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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention (Technical Field)
[0002] The present invention relates to digital messaging and more particularly to the integration of legacy and new mission display systems with the military data link radios and the implementation of the Link 16 message set defined by MIL-STD-6016 and associated message processing capabilities.
[0003] 2. Background Art
[0004] The military uses various tactical data link radios to send and receive digital voice and data between their air, land, sea and space vehicles, and command and control facilities. On each vehicle and in each command and control facility, these data link radios are interfaced to various mission computers and display systems. The data transmitted across these data link radios consists of messages, message formats, and message protocols defined by various message standards. The mission and display systems use the data contained in these messages from external sources and generate the data put into these messages sent to external systems.
[0005] Some examples of military data link radios are UHF line of sight (LOS) radios, UHF DAMA SATCOM, EHF MDR SATCOM, HF radios, Joint Tactical Information Distribution System (JTIDS), Multi-function Information Distribution System (MIDS), and Joint Tactical Radio System (JTRS). Military data link message standards can be Link 4, Link 11, Link 16, Link 22, and the Variable Message Format (VMF). Examples of mission and display systems are vehicle controls and displays equipment, mission computers, workstations, and network servers.
[0006] The Department of Defense (DoD) has recently selected the Link-16 data link message set (in accordance with MIL-STD-6016) as the standard for use on military platforms for tactical data link operations. In addition, the DoD is currently developing the Joint Tactical Radio System (JTRS) to use as the standard data link radio system. Each existing (legacy) and future military platform will use the JTRS with the Link 16 message set for its tactical data link capability.
[0007] As outlined in the DoD Command, Control, Communications, Computers, and Intelligence (C4I) Joint Tactical Data Link Management Plan (dated June 2000), a wide range of legacy military platforms will be upgraded to incorporate the JTRS with the Link-16 message set through 2015 and beyond. These same legacy platforms are currently deployed with existing subsystems that generate information used by or consume information provided by various existing and disparate military data link systems. When the new JTRS equipment is introduced into these legacy platforms, there will be a need to interface the existing platform subsystems with the new JTRS equipment. Also, each existing subsystem will need to be upgraded to utilize the new and evolving Link 16 message set.
[0008] Since most of these existing platform subsystems were developed in the past, they either implement a subset of the Link 16 message set, or they implement a different and older data link message set such as Link 4 or Link 11. Also, many existing subsystems were designed to interface with older data link radio equipment and are not compatible with the newer data link radio equipment and message processing protocols. Each of these prior art systems are point solutions unique to the specific platform they are implemented on, and they are each provided by a specific company. These point solutions include receive, transmit, and processing functions. Receive functions receive the message from the data link radio, decode the message data, and send the data to the appropriate subsystem. Transmit functions collect specific data from platform subsystems, encode the data into the proper message format, and send the message to the data link radio. Processing functions act on selected data elements to perform specific tasks such as filtering, correlation, keeping track files, and other mission specific functions. Each solution only implements the subset of messages required for that platform's mission. When future changes are needed because the military wants to add, delete or modify specific messages and message processing for the platform, the military must return to the previous point solution company and pay them to implement the changes. Thus, the existing product solutions do not provide the military with the capability of modifying specific messages without a major product redesign on each unique platform. For example, on fighter aircraft the mission computer interfaces to the existing data link radio and performs the message processing for the message subset implemented on the specific fighter. The display system also processes those messages that contain situational awareness information, but tailors it for the specific fighter mission and display requirements.
[0009] There are many different implementations of data link integration used in the United States military aircraft as well as NATO countries. Each of these are point solutions that were designed specifically for the aircraft they are used on. A specific example is the Data Link Interface Processor (DLIP) provided by Thales Communications. However, these existing implementations do not offer the benefits of the Military Data Link Integration Application:
They only implement a subset of the full J-Series message set. They are not user programmable. Any addition or deletion of messages or special message processing functions requires redesign of the operational software. They do not use API databases to allow I/O re-configuration without modification. They do not provide standard display system interfaces and video outputs.
[0014] As a result, the upgrade costs for these existing platform subsystems will be enormous if traditional subsystem upgrade approaches are used. Traditional upgrade approaches involve point solutions and upgrades by different integrators on each platform application. A need exists for a common and low cost military data link integration (MDLI) product that can be used in multiple and disparate platform applications.
SUMMARY OF THE INVENTION
Disclosure of the Invention
[0015] The present invention implements a common scalable design that can be used on each and every platform application. The invention implements the complete or full Link 16 J-Series message set with a database driven design so that the military user can control message activation, message deactivation, and message processing instructions for each platform application. The database used for this capability is created by and maintained by the military user. The military does not need to pay any company to do this for them. This allows the common MDLI product to work on each unique platform without the need to recompile the operational software.
[0016] The present invention implements a database driven design that allows automatic re-configuration of the MDLI product for each unique platform without the need for software changes to the product. The database used for this capability contains the interface instructions for each type of subsystem used on each unique platform and allows the common MDLI product to work on each unique platform without the need to recompile the operational software.
[0017] The present invention implements special message processing functions. These functions provide correlation of similar data from disparate sources, target track files, formatting of data into situational awareness display formats, automatic event triggers and associated actions, automatic triggers for transmit messages, mission recording and playback, and others. In addition, the present invention provides standard video outputs for Link 16 display formats.
[0018] A primary object of the present invention is to provide a common scalable design that can be used on each and every platform application
[0019] One advantage of the Military Data Link Integration Application is that it provides the military with a low cost solution. The user can tailor how the Military Data Link Integration Application works on each unique host platform simply by updating the Applications Programming Interface (API) Databases and User Modifiable Instructions (UMI) Databases. This gives the user control over the use and operation of the solution without the need to pay someone to modify it for them.
[0020] Another advantage of the Military Data Link Integration Application is that it is flexible, scalable, and reusable for each unique host platform. Through the API Database it can be used on multiple unique host platforms to interface with available communications subsystems and legacy subsystems without any required modifications.
[0021] Yet another advantage of the Military Data Link Integration Application is that it implements the complete set of Link 16 messages and processing rules defined in MIL-STD-6016. The user can then activate or deactivate messages as required for each unique host platform.
[0022] Another advantage of the Military Data Link Integration Application is that it implements special message processing functions and utilities that can be activated or deactivated by the user. These message processing functions and utilities allow the user to add value to the data and messages sent by the Military Data Link Integration Application to available communications subsystems and legacy subsystems on the host platform.
[0023] Another advantage of the Military Data Link Integration Application is that it provides standard display system interfaces to support flexible and user programmable display formats to view Link 16 data and legacy subsystem data.
[0024] Another advantage of the Military Data Link Integration Application is the Ground Based Software Tool that allows users to define and create the API Databases and UMI Databases on a workstation in an office environment.
[0025] Another advantage of the Military Data Link Integration Application common solution is that is saves the user money on training and maintenance costs across all host platforms.
[0026] Other objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating a preferred embodiment of the invention and are not to be construed as limiting the invention. In the drawings:
[0028] FIG. 1 depicts the military data link integration application implantation on a host processor;
[0029] FIG. 2 is a flow chart that shows the preferred military data link integration application;
[0030] FIG. 3 is a flow chart showing the data link message processing flow;
[0031] FIG. 4 is a flow chart showing the data link platform integration processing flow;
[0032] FIG. 5 shows the military data link integration application hosted on a general purpose processor module; and
[0033] FIG. 6 shows the military data link integration application hosted on an image processing module.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Best Modes for Carrying out the Invention
[0034] The Military Data Link Integration Application is a software partition that executes on a host processor. FIG. 1 illustrates how the Military Data Link Integration Application 100 software partition is implemented. This same implementation is envisioned for each platform in which the Military Data Link Integration Application is used. The Military Data Link Integration Application consists of the following functions: Data Link Message Processing 200 , Data Link Platform Integration 400 , Application Programming Interface (API) Database 300 , Message Parameter Database 340 , and User Modifiable Instructions (UMI) Database 350 . These Military Data Link Integration Application functions ( 200 through 400 ) are implemented in a computer system available on each host platform. The host computer system is expected to consist of a Host Applications Processor 632 module, Legacy Image Processing Module (IPM) 634 , Legacy Input and Output (I/O) Modules 636 , and a computer cabinet with the necessary Legacy Computer Module Interconnects 638 . The Military Data Link Integration Application functions ( 200 through 400 ) execute on the Host Applications Processor 632 and interface with legacy software Mission Applications 630 that are also executing on the Host Applications Processor 632 through pre-defined API data exchange protocols in the API Database 300 . The Military Data Link Integration Application functions ( 200 through 400 ) also interface with external Communications Subsystems 500 and other Legacy Subsystems 600 through the host computer system Legacy IPM 634 , Legacy I/O Modules 636 , and their associated Legacy Computer Module Interconnections 638 . The pre-defined data exchange protocols consist of host computer system port addresses, message structures and formats, and data exchange command sequences. The Military Data Link Integration Application functions ( 200 through 400 ) utilize these host computer resources ( 632 , 634 , 636 and 638 ) to exchange data with external subsystems ( 500 and 600 ) over pre-defined system interfaces Legacy I/O 660 and Link 16 Messages 550 . Additionally, the Military Data Link Integration Application databases ( 300 and 350 ) can be created off the platform on a Ground Based Software Tool 700 . These databases can then be uploaded to the Host Application Processor 632 memory through a data loader within the Legacy Subsystems 600 using a Data Loader Cartridge 702 . These databases ( 300 and 350 ) are used by the Data Link Message Processing 200 and Data Link Platform Integration 400 functions to automatically configure the Military Data Link Integration Application on the host platform, and to implement user defined instructions.
[0035] FIG. 2 illustrates the Military Data Link Integration Application 100 approach consisting of its major functions Data Link Message Processing 200 and Data Link Platform Integration 400 . It also includes the API Database 300 , the Message Parameter Database 340 , and the User Modifiable Instructions (UMI) Database 350 . The Data Link Message Processing 200 function implements the Link 16 message set with its processing rules and special message functions. It interfaces with the Communications Subsystems 500 on the host platform, databases ( 300 , 340 and 350 ), and the Data Link Platform Integration 400 function. The Data Link Platform Integration 400 function implements the rules and instructions needed to interface with and interact with the various Legacy Subsystems 600 on the host platform, as well as Special Platform Functions 460 , under the control of the Data Link Message Processing 200 function. Control is accomplished through the Control and Status Exchange 320 interface. The Data Link Platform Integration 400 function also implements the data loader function that is used to update the API Database 300 and the UMI Database 350 using the host platform's Data Loader 640 device.
[0036] FIG. 3 provides the Data Link Message Processing 200 functional flow chart. The processing flow illustrated in FIG. 3 implements the functions 210 through 260 identified on FIG. 2 . The Automatically Configurable API 210 function shown on FIG. 2 is implemented in processes 212 through 224 of FIG. 3 . The Decode Messages 230 function shown on FIG. 2 is implemented in processes 230 and 232 of FIG. 3 . The Encode Messages 240 function shown on FIG. 2 is implemented in processes 240 and 242 of FIG. 3 . The function Standard Message Processing and Link 16 Network Management Rules per MIL-STD-6016 250 shown on FIG. 2 is implemented in processes 252 through 256 of FIG. 3 . The Special Message Functions 260 shown on FIG. 2 is implemented in process 260 of FIG. 3 .
[0037] The Data Link Message Processing 200 function processing flow is as follows. As shown in FIG. 3 , Startup 212 occurs after application of power when the Host Applications Processor 632 ( FIG. 1 ) initiates the execution of the Data Link Message Processing 200 function. The Initialize Communications Interface 214 task is executed to establish the interfaces to the Communications Subsystems 500 using pre-defined instructions in the Communications Equipment API 302 database obtained through the API Configurations 310 interface ( FIG. 2 ). This database contains the instructions to identify which Communications Subsystems 500 are available on the host platform. The database also provides Host Applications Processor 632 interface port addresses and protocols, message structures and formats, and command sequences to accomplish data exchange for each of the available communications subsystems ( 510 through 540 ). After initialization is complete, Receive Messages 216 task is executed to poll each available Communications Subsystem ( 510 through 540 ) for incoming Link 16 Messages 550 . These incoming messages are received into Receive Message Queue 222 . Decode Messages 230 task is then executed to unpack each received message in Receive Message Queue 222 and extract the data contained within each message. The extracted data is placed in Receive Message Data 232 storage area. Process Input Data 252 task is then executed to process incoming Link 16 data in accordance with the message processing rules defined in MIL-STD-6016 254 . All Link 16 message processing rules are contained in MIL-STD-6016 Message Rules 254 data storage area. Process Input Data 252 task uses pre-defined Message Processing Instructions 354 to determine which Link 16 messages have been activated for the host platform and then uses the appropriate MIL-STD-6016 Message Rule 254 on received message data 232 . Message parameters obtained from incoming data are stored in Message Parameter Database 340 . Execute Special Message Functions 260 task is then executed. Execute Special Message Functions 260 task uses Data Collection Instructions 356 to identify data parameters to be collected from Legacy Subsystems 600 on the host platform. These collected data parameters are stored in Message Parameter Database 340 . Execute Special Message Functions 260 task uses Message Processing Instructions 354 to activate utilities on user specified data parameters. These utilities include data fusion algorithms, creation and update of track files, creation and update of shared situational awareness (SSA) information, and other user defined data operations. The results of these utility operations are stored in Message Parameter Database 340 . Execute Special Message Functions 260 task uses Routing Instructions 352 to identify data in Message Parameter Database 340 to be sent to specific Legacy Subsystems 600 and Communications Subsystems 500 . Execute Special Message Functions 260 task uses Display Format Instructions 358 to format selected data in Message Parameter Database 340 for display. Process Output Data 256 task is then executed. This task formats the data tagged in Message Parameter Database 340 for output to available Communications Subsystems 500 . The tagged data is formatted in accordance with MIL-STD-6016 Message Rules 254 , and then is placed in Transmit Message Data 242 buffer. Encode Messages 240 task is then executed to encode the output data into the appropriate message format and to place these formatted messages in Transmit Message Queue 224 . Transmit Messages 218 task is then executed to send each transmit message to the appropriate Communications Subsystem ( 510 , 520 , 530 , or 540 ). A check is made to decide if it is time to Shutdown 220 . If not, then Data Link Message Processing 200 function repeats itself by starting again with Receive Message 216 task. This process is repeated at a pre-defined update rate. Otherwise, Data Link Message Processing 200 function is Shutdown 222 .
[0038] FIG. 4 provides the Data Link Platform Integration Processing 400 functional flow chart. The processing flow illustrated in FIG. 4 implements the functions 410 through 460 identified on FIG. 2 . Automatically Configurable API 410 function ( FIG. 2 ) is implemented in processes 412 through 424 of FIG. 4 . Decode Data 430 function ( FIG. 2 ) is implemented in processes 430 and 432 in FIG. 4 . Encode Data 440 function ( FIG. 2 ) is implemented in processes 440 and 442 of FIG. 4 . Function Rules and Instructions for Unique Host Platform Requirements 450 ( FIG. 2 ) is implemented in processes 452 through 456 of FIG. 4 . Special Platform Functions 460 ( FIG. 2 ) is implemented in process 460 of FIG. 4 .
[0039] Data Link Platform Integration Processing 400 function processing flow is as follows. Startup 412 occurs after application of power when Host Applications Processor 632 ( FIG. 1 ) initiates the execution of Data Link Platform Integration Processing 400 function. Initialize Legacy Interfaces 414 task is executed to establish the interfaces to Legacy Subsystems 600 using pre-defined instructions in the Displays Equipment API 304 database, Mission Equipment API 306 database, and Platform Unique API 308 database using API Configurations 310 interface ( FIG. 2 ). These databases contain the instructions to identify which Legacy Subsystems 600 are available on the host platform. These databases also provide Host Applications Processor 632 interface port addresses and protocols, message structures and formats, and command sequences to accomplish data exchange for each of the available legacy subsystems ( 610 through 650 ). After initialization is complete, Receive Data 416 task is executed to poll each available Legacy Subsystem ( 610 through 650 ) for incoming Legacy I/O 660 . The incoming data is received into Receive Data Queue 422 . Decode Data 430 task is then executed to unpack each received data item in Receive Data Queue 422 and extract the data from the legacy subsystem message format. The extracted data is placed in Receive Data 432 buffer. Process Input Data 452 task is then executed to process incoming data in accordance with Platform Integration Rules 454 . Process Input Data 452 task uses pre-defined Platform Application Instructions 360 to determine which legacy subsystems have been activated for the host platform and then uses the appropriate Platform Integration Rules 454 on Receive Data 432 . Message parameters obtained from incoming data are stored in Message Parameter Database 340 . Execute Special Platform Functions 460 task is then executed. Execute Special Platform Functions 460 task uses Data Collection Instructions 356 to identify data parameters to be collected from Legacy Subsystems 600 on the host platform. These collected data parameters are stored in Message Parameter Database 340 . Execute Special Platform Functions 460 task uses Platform Application Instructions 360 to activate utilities on user specified data parameters. These utilities include display applications, mission applications, and other user defined data operations. The results of these utility operations are stored in Message Parameter Database 340 . Execute Special Platform Functions 460 task uses Display Format Instructions 358 to format selected data in Message Parameter Database 340 for display. Process Output Data 456 task is then executed. This task formats the data tagged in Message Parameter Database 340 for output to available Legacy Subsystems 600 . The tagged data is formatted in accordance with Platform Integration Rules 454 , and then is placed in Transmit Data 442 buffer. Encode Data 440 task is then executed to encode the output data into the appropriate message format and to place these formatted messages in Transmit Data Queue 424 . Transmit Data 418 task is then executed to send each transmit data message to the appropriate Legacy Subsystem ( 610 , 620 , 630 , 640 or 650 ). A check is made to determine if it is time to Shutdown 420 . If not, then Data Link Platform Integration Processing 400 function repeats itself by starting again with Receive Data 416 task. This process is repeated at a pre-defined update rate. Otherwise, Data Link Platform Integration Processing 400 function is Shutdown 425 .
[0040] A capability of the Military Data Link Integration Application is the ability to automatically initialize its interfaces to Communications Subsystems 500 on the host platform. This capability allows the Military Data Link Integration Application to be hosted on many different host platforms without the need to modify it for different communications equipment configurations. Automatically Configurable API 210 , shown on FIG. 2 , uses Communications Equipment API 302 database to obtain instructions to identify which Communications Subsystems ( 510 through 540 ) are available on the host platform. Communications Equipment API 302 database also provides Host Applications Processor 632 ( FIG. 1 ) interface port addresses and protocols, message structures and formats, and command sequences to accomplish data exchange for each of the available communications subsystems ( 510 through 540 ). Communications Equipment API 302 database is created off the platform using Ground Based Software Tool 700 shown in FIG. 1 . Ground Based Software Tool 700 is provided on a workstation in an office environment. This tool is used to define the interface port addresses and protocols, message structures and formats, and command sequences to accomplish data exchange for each of the communications subsystems available on a specific platform and to create the associated Communications Equipment API 302 database for the host platform. This Communications Equipment API 302 database is then copied to a Data Loader Cartridge 702 ( FIG. 1 ). Data Loader Cartridge 702 is then used on the host platform to load Communications Equipment API 302 database into Military Data Link Integration Application API Database 300 storage area through host platform Data Loader 640 shown in FIG. 2 . The instructions in Communications Equipment API 302 database are used by Initialize Communications Interface 214 task ( FIG. 3 ) to automatically configure Data Link Message Processing 200 functions for the host platform communications subsystems ( 510 through 540 in FIG. 2 ). Communications Equipment API 302 database is also used by Receive Messages 216 task and Transmit Messages 218 task to automatically configure these tasks to exchange incoming and outgoing messages with the available host platform communications subsystems ( 510 through 540 ).
[0041] Another capability of the Military Data Link Integration Application is the ability to automatically initialize its interfaces to Legacy Subsystems 600 on the host platform. This capability allows the Military Data Link Integration Application to be hosted on many different host platforms without the need to modify it for different legacy mission and displays equipment configurations. Automatically Configurable API 410 ( FIG. 2 ) uses Displays Equipment API 304 database, Mission Equipment API 306 database, and Platform Unique API 308 database to obtain instructions to identify which legacy subsystems ( 610 through 650 ) are available on the host platform. The databases ( 304 , 306 and 308 ) also provide Host Applications Processor 632 ( FIG. 1 ) interface port addresses and protocols, message structures and formats, and command sequences to accomplish data exchange for each of the available legacy subsystems ( 610 through 650 ). The instructions in the databases ( 304 , 306 and 308 ) are used by Initialize Legacy Interfaces 414 task, shown in FIG. 4 , to automatically configure Data Link Platform Integration Processing 400 functions for the host platform legacy subsystems ( 610 through 650 in FIG. 2 ). The databases ( 304 , 306 and 308 ) are also used by Receive Data 416 task and Transmit Data 418 task to automatically configure these tasks to exchange incoming and outgoing data with the available host platform legacy subsystems ( 610 through 650 ).
[0042] Another capability of the Military Data Link Integration Application is the ability to implement user specified instructions associated with Link 16 message processing and unique host platform functions. This capability allows the user to tailor how Link 16 messages are processed, to define special message processing functions, and to define special platform integration functions without the need to modify the Military Data Link Integration Application for each host platform configuration. Several databases are used to implement this capability. These databases, shown on FIG. 2 , are Routing Instructions 352 database, Message Processing Instructions 354 database, Data Collection Instructions 356 database, Display Format Instructions 358 database, and Platform Application Instructions 360 database. Routing Instructions 352 database provides instructions that identify data to be routed and the associated source and destination information. Source instructions identify the Link 16 message in which the data is contained or the legacy subsystem that provides the data. Destination instructions identify the Link 16 message in which the data is required or a legacy subsystem that required the data. Execute Special Message Functions 260 task, shown in FIG. 3 , uses Routing Instructions 352 database to identify and tag source data in Message Parameter Database 340 , shown in FIG. 2 , to be sent to specific legacy subsystems ( 610 through 650 ) and communications subsystems ( 510 through 540 ). The source data tagged for Link 16 messages is then processed by Process Output Data 256 task ( FIG. 3 ), Encode Messages 240 task ( FIG. 3 ) and Transmit Messages 218 task ( FIG. 3 ). This data is incorporated into Link 16 messages that are sent to the available communications subsystems ( 510 through 540 ). The source data tagged for legacy subsystems is then processed by Process Output Data 456 task ( FIG. 4 ), Encode Data 440 task ( FIG. 4 ) and Transmit Data 418 task ( FIG. 4 ). This data is incorporated into messages that are sent to the available legacy subsystems ( 610 through 650 ). Message Processing Instructions 354 database provides instructions that identify which Link 16 messages to activate or deactivate, and which utility functions to activate for specific data items. Message Processing Instructions 354 database is used by Process Input Data 252 task, ( FIG. 3 ), to identify which Link 16 messages have been activated for the host platform and then uses the appropriate MIL-STD-6016 Message Rules 254 on received message data 232 . Message parameters obtained from incoming messages are stored in Message Parameter Database 340 . Execute Special Message Functions 260 task also uses Message Processing Instructions 354 database to activate utilities on user specified data parameters. These utilities include data fusion algorithms, creation and update of track files, creation and update of shared situational awareness (SSA) information, and other built-in data operations. The results of these utility operations are stored in Message Parameter Database 340 . Data Collection Instructions 356 database provides instructions that identify what data is to be collected from the available communications subsystems ( 510 through 540 ) and legacy subsystems ( 610 through 650 ). Data Collection Instructions 356 database is used by Execute Special Message Functions 260 task, ( FIG. 3 ), to identify data parameters to be collected from available communications subsystems ( 510 through 540 ) on the host platform. These collected data parameters are stored in Message Parameter Database 340 . Data Collection Instructions 356 database is also used by Execute Special Platform Functions 460 task, ( FIG. 4 ), to identify data parameters to be collected from legacy subsystems ( 610 through 650 ) on the host platform. These collected data parameters are stored in Message Parameter Database 340 . Display Format Instructions 358 database provides instructions that identify what data needs to be formatted for display and what display formats to send to Display Subsystem 610 . Display Format Instructions 358 database is used by Execute Special Message Functions 260 task ( FIG. 3 ) to identify Link 16 message data in Message Parameter Database 340 that needs to be formatted, and what formatting instruction to use. The formatted data is placed in Message Parameter Database 340 . Display Format Instructions 358 database is also used by Execute Special Platform Functions 460 task ( FIG. 4 ) to identify legacy subsystem data in Message Parameter Database 340 that needs to be formatted, and what formatting instruction to use. The formatted data is placed in Message Parameter Database 340 . The formatted display data and selected display format information contained in Message Parameter Database 340 is then used by Process Output Data 456 task, Encode Data 440 task, and Transmit Data 418 task to send the formatted display data and selected display format information to Display Subsystem 610 ( FIG. 2 ) on the host platform. Platform Application Instructions 360 database provides instructions that identify which platform utility functions to activate. Process Input Data 452 task ( FIG. 4 ) uses pre-defined Platform Application Instructions 360 to determine which legacy subsystems have been activated for the host platform and then uses the appropriate Platform Integration Rules 454 on Receive Data 432 . Message parameters obtained from incoming data are stored in Message Parameter Database 340 . Execute Special Platform Functions 460 task also uses Platform Application Instructions 360 database to activate utilities on user specified data parameters. These utilities include display applications, mission applications, logic operations, preferred channel selections, service operational preference tables, mission record and playback, and other user defined data operations. The results of these utility operations are stored in Message Parameter Database 340 . Another capability of the Military Data Link Integration Application is the ability to create its databases ( 302 through 308 and 352 through 360 ) off the host platform using Ground Based Software Tool 700 shown in FIG. 1 . Ground Based Software Tool 700 is provided on a workstation in an office environment. This tool is used to collect information, to define and create data and data structures, and to define and create the associated instructions required in each database ( 302 through 308 and 352 through 360 ). Once created, the databases ( 302 through 308 and 352 through 360 ) are then copied to a Data Loader Cartridge 702 ( FIG. 1 ). Data Loader Cartridge 702 is then used on the host platform to load the individual databases ( 302 through 308 and 352 through 360 ) into API Database 300 storage area and UMI Database 350 storage area through host platform Data Loader 640 shown in FIG. 2 .
[0043] Since the Military Data Link Integration Application is a software partition, it can be implemented in an existing computer system on the host platform as illustrated in FIG. 1 . It can also be hosted on a General Purpose Processor module 680 illustrated in FIG. 5 , or an Image Processing Module 690 illustrated in FIG. 6 .
[0044] In FIG. 5 API Database 300 is used to define the interfaces between Military Data Link Integration Application and Mission Applications 630 executing on Host Applications Processor 632 . API Database 300 is also used to define the interfaces to Legacy IPM 634 and Legacy I/O Modules 636 .
[0045] In FIG. 6 API Database 300 is used to define the interfaces between the Military Data Link Integration Application and Mission Applications 630 executing on Host Applications Processor 632 . API Database 300 is also used to define the interfaces to Legacy I/O Modules 636 . Legacy IPM 634 is eliminated because it is replaced with Image Processing Module 690 .
[0046] The advantage of hosting the Military Data Link Integration Application on a General Purpose Processor module or an Image Processing Module is that these provide more flexibility in implementing the Military Data Link Integration Application on host platforms that do not have an existing computer system. In the alternative, the existing computer system may not have the processing and memory resources required for the Military Data Link Integration Application. In these cases, the General Purpose Processor module or Image Processing Module can be integrated into any legacy subsystem equipment that has a spare card slot.
[0047] Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above, are hereby incorporated by reference.
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The military data link integration solution provides a common and reusable approach to interface tactical data link radios with legacy subsystems on each unique military platform. The solution implements the full Link 16 J-Series message set. Enhancements are provided that allow the military user to activate or deactivate specific messages for each unique platform and to customize message processing and display selections through user defined instructions. The solution also provides the capability to automatically re-configure itself for subsystem interfaces and the integration of subsystem functions on each unique platform without the need to modify the product.
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BACKGROUND OF THE INVENTION
This invention relates to a process for hydrogenating conjugated diene polymers and more particularly, to the process for hydrogenating the unsaturated double bonds of the diene units of conjugated diene polymer, wherein the unsaturated double bonds of conjugated diene polymers, which has been widely used as a modifier for transparent impact-resistant resin or polyolefin and polystyrene resin, is saturated via hydrogenation in the presence of a novel homogeneous catalyst of the organotitanium in the absence of a separate reducing agent, thus representing a high hydrogenation yield with a good reaction reproducibility.
Some polymers of conjugated diene such as 1,3-butadiene or isoprene, have been widely applicable as an elastomer in the industrial field, together with copolymers formulated by these conjugated dienes and copolymerization-possible aromatic vinyl monomers(e.g., styrene, etc.). Since these polymers have a double bonds within their internal chain, their vulcanization is made available but with poor durability and poor resistance to oxidation.
The conjugated diene-aromatic vinyl monomer block copolymers which are not vulcanized, have been as thermoplastic elastomer used for a transparent impact-resistant resin, or for a modifier for polyolefin and polystyrene resin. However, the double bonds in these copolymers are concerned directly with poor durability and poor resistance against oxygen and ozone in the air.
Under such situation, these copolymers need to be used within limited scope of application, while not being exposed to the external environment.
To overcome the shortcomings as aforementioned, a method designed to improve the durability and oxidative resistance of these polymers is to hydrogenate the internal double bonds for saturation in part or whole.
In polymers with the olefinical double bonds, the method of adding hydrogen to the internal double bonds is generally classified into the following two types: (a)a method of using heterogeneous catalysts, and (b)a method of using homogeneous catalyst belonging to Ziegler type catalyst or the organometallic compounds such as Rh and Ti.
According to the hydrogenation of using the heterogeneous catalyst, the olefinic polymers are dissolved in an appropriate solvent and then, contacted with hydrogen in the presence of a heterogeneous catalyst. However, shch method has recognized some disadvantages in that (a) due to adverse factors such as steric hindrance of polymers and relatively high viscosity, the contact may not be easily made between the reactant and catalyst, and (b) if hydrogenation is successfully achieved due to strong adsorption of both the polymer and catalyst, their not easily detachable bonding characteristics make other unhydrogenated polymers extremely difficult to reach the activated point.
The complete addition of hydrogen to the double bonds in the case of the heterogeneous catalyst should require a large volume of catalyst including severe conditions such as high temperature and high pressure, which may result in degradation of polymer and gelation as well. In particular, in case of copolymers comprising conjugated dienes and aromatic vinyl mononers, the saturation of the double bonds in an aromatic compound is simultaneously performed, which makes it difficult to selectively hydrogenate the double bonds of olefinic polymer only.
In addition, physical separation of the residual catalyst from the resulting polymer solution after hydrogenation would be extremely difficult, and a part of heterogeneous catalyst is strongly absorbed to the polymer, whereby its removal is not completely made available.
In contrast to the hydrogenation of using heterogeneous system catalyst, a hydrogenation designed to use a homogeneous catalyst is characterized in that (a) catalytic activity is high, and (b) with less amounts of catalyst, hydrogenation can be made available with higher yield under a mild conditions, i.e., low-temperature and low-pressure.
On top of that, if the homogeneous catalyst is used, its advantage is to selectively hydrogenate the olefinic double bonds only among the chains of copolymer consisting of aromatic vinyl hydrocarbon and conjugated dienes under appropriate hydrogenation conditions.
Notwithstanding this, hydrogenation of the unsaturated double bonds using the homogeneous catalyst is responsible for lowering the stability of catalyst itself, and the separation of the deactivated catalyst from hydrogenated polymers becomes extremely difficult.
Meantime, several hydrogenations or selective hydrogenation involved in the conjugated diene polymers were disclosed in the prior arts. For example, in order to hydrogenate or selectively hydrogenate the polymer containing an ethylenically unsaturated double bonds, or the polymer having aromatic and ethylenically unsaturated double bonds, the methods of using appropriate catalysts published in the prior arts, preferably some catalysts containing 8-, 9- and 10-group metals or precursor of catalysts, were disclosed in the U.S. Pat. No. 3,494,942, No. 3,634,594, No. 3,670,054, and No. 3,700,633.
According to these methods, the catalyst includes 9- and 10-group metals, especially some catalyst prepared by nickel or cobalt compounds in combination with an appropriate reducing agent such as alkyl aluminium. The prior arts disclosed that in addition to alkyl aluminium, 1-, 2- and 13-group metals in the Periodic Table of the Elements, especially lithium, magnesium and aluminium alkyl or hydride, might be used as an effective reducing agent. In general, the blending ratio of both 1-, 2- and 13-group metals and 8-, 9- and 10-group metals is in the molar ratio of 0.1:1 to 20:1, preferably in the molar ratio of 1:1 to 10:1.
The U.S. Pat. No. 4,501,857 has also disclosed that via hydrogenation of conjugated diene polymer in the presence of one bis(cyclopentadienyl)titanium compound at least and one hydrocarbon lithium compound at least, the double bonds within the polymer may be selectively hydrogenated.
Further, the U.S. Pat. No. 4,980,421 has also disclosed that pseudo-hydrogenation activity may develop via combination of alkoxy lithium compound with bis(cyclopentadienyl) titanium compound, which may be directly added or as a mixed form of organolithium compound and alcoholic or phenolic compound. This invention has reported that the catalytic activity was quite effective even less catalyst used and the residual amount of catalyst did not reversely affect the stability of hydrogenated polymer formed after hydrogenation Another hydrogenation process using bis(cyclopentadienyl)titanium diaryl compound as bis(cyclopentadienyl)titanium compound was disclosed in the U.S. Pat. No. 4,673,714. According to this invention, the unsaturated double bonds of conjugated diene were hydrogenated in the absence of hydrocarbon lithium compound.
Further, there was another process of hydrogenating a conjugated diene polymer including generation of a living polymer via polymerization or copolymerization of conjugated diene monomer as an initiator of organo-alkalimetal polymerization in the presence of an appropriate solvent, which was disclosed in the U.S. Pat. No. 5,039,755. According to this invention, the polymerization of the living polymer, so formed, is terminated with the addition of hydrogen. From a conjugated diene unit of terminated polymer, the selective hydrogenation of the double bonds was carried out via a catalyst expressed by (C 5 H 5 ) 2 TiR 2 (wherein R is a arylalkyl group).
Another method of hydrogenating the double bonds of conjugated diene was disclosed in the U.S. Pat. No. 5,583,185 via use of a catalyst represented by (C 5 H 5 ) 2 Ti(PhOR) 2 or (C 5 H 5 ) 2 TiR 2 as a homogeneous system catalyst.
However, the hydrogenation activity of such homogeneous system catalysts differs greatly depending on the reduced state of catalyst and then, the reproducibility of hydrogenation may be lowered. Thus, a high-yield hydrogenated polymer with high reproducibility cannot be easily obtained.
Further, when the reaction is being carried out, there is a trend that some active ingredients of catalyst is contaminated into the inactive ones by the impurities. This is liable to lower the hydrogenation activity which may result in poor reaction reproducibility.
In the homogeneous catalyst, the hydrogenation yield is significantly affected by the stability of catalyst during the hydrogenation process.
Therefore, hydrogenation of a polymer based on the homogeneous catalyst has encountered a lot of problems, when applied to the industrial scale.
Under such situation, the implementation of more economical hydrogenation process should require more effective, high-active and stable catalyst with less amount than the conventional homogeneous system catalysts. Further, a novel catalyst needs to be made available so as to avoid any complicated process to remove catalyst residues from the hydrogenated polymer after reaction.
SUMMARY OF THE INVENTION
An object of this invention is to provide a process of hydrogenating conjugated diene polymers using a catalyst synthesized by bis(cyclopentadienyl)titanium compound and thiophene compound so as to produce a hydrogenated polymer with high hydrogenation yield and remarkable reproducibility, without problems the conventional homogeneous catalysts have faced.
To achieve the above object, the process for hydrogenating a conjugated diene polymers according to this invention is characterized in that a homopolymer of conjugated diene monomer, or a conjugated dine monomer-aromatic vinyl monomer copolymer, is hydrogenated under the presence of a novel catalyst represented by the following formula I.
Formula I. ##STR2## Wherein Cp is a cyclopentadienyl (C 5 H 5 ) group; R 1 , R 2 and R 3 are hydrogen atom or alkyl group of 1 to 3 carbon atoms; and
R 1 , R 2 and R 3 can be the same or different.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
This invention is explained in more detail as set forth hereunder.
This invention relates to the process for hydrogenating a conjugated diene polymer in the presence of a catalyst formulated by bis(cyclopentadienyl)titanium compound and thiophene compound. The catalyst used for this invention is a compound represented by the above formula I. The above compound may be used by selecting one or more compounds from the following groups:
bis(cyclopentadienyl)-bis(thienyl)titanium,
bis(cyclopentadienyl)-bis(4-methyl thienyl)titanium,
bis(cyclopentadienyl)-bis(3-methyl thienyl)titanium,
bis(cyclopentadienyl)-bis(2, 4-dimethyl thienyl)titanium,
bis(cyclopentadienyl)-bis(4-ethyl thienyl)titanium,
bis(cyclopentadienyl)-bis(3-ethyl thienyl)titanium and,
bis(cyclopentadienyl)-bis(2,4-diethyl thienyl)titanium,
The hydrogenation catalyst of this invention can be synthesized in accordance with the method published in the existing literature (Zh. Obshch. khim. 1982, 52(7), 1571-5).
Meantime, it is preferred that the amount of the hydrogenation catalyst used for this invention is in the range of 0.05 to 5 mmol per 100 g of polymer, more preferably in the range of 0.1 to 2 mmol per 100 g of polymer.
If the amount of the hydrogenation catalyst used for this invention is less than 0.05 mmol, the hydrogenation rate of conjugated diene is not significantly high; in case of exceeding 5 mmol, its excessive use is deemed uneconomical, even though the hydrogenation yield is significantly high.
It is preferred that the molecular weight of a polymer is about 500 to 1,000,000, when it is hydrogenated in the presence of a hydrogenation catalyst of this invention. The selective hydrogenation of unsaturated double bonds in the following polymers is available: a homopolymer of conjugated diene monomer, or a copolymer consisting of conjugated diene monomer and copolymerization-possible vinyl-substituted aromatic monomer, or conjugated diene units of random or block copolymer.
As already reported, some polymers containing ethylenically unsaturated double bonds and optional aromatic unsaturated double bonds, may be synthesized by polymerizing one or more polyolefins, especially diolefin individually, or by copolymerizing one or more alkenyl aromatic hydrocarbon monomers. The copolymer is linear, star or radial types including random, tapered, block or combination thereof.
In case of a copolymer containing ethylenically unsaturated double bonds, or a copolymer containing both aromatic unsaturated double bonds and ethylenically unsaturated double bonds, its preparation may be available using anionic initiator such as organolithium compound or polymerization catalyst.
The above polymer may be synthesized via commonly available bulk polymerization, solution polymerization, or emulsion polymerization.
The conjugated dienes, which can be polymerized in an anionic type, includes the ones of 4 to 12 carbon atoms such as 1,3-butadiene, isoprene, piperylene, phenylbutadiene, 3,4-dimethyl-1,3-hexadiene and 4,5-diethyl-1,3-octadiene. It is preferred to use a conjugated diolefin of 4 to 9 carbon atoms.
The alkenyl aromatic hydrocarbon compounds, which can be copolymerized with the conjugated dienes, include styrene, styrene substituted with various alkyl groups, alkoxy substituted styrene, 2-vinyl pyridine, 4-vinyl pyridine, vinyl naphthalene, and vinyl aryl compound such naphthalene substituted with various alkyl groups.
In hydrogenating these copolymers, it is preferred to carry out the hydrogenation in such a manner that a living polymer solution, so formed via polymerization of these conjugated dienes in inert solvents, is subject to hydrogenation as it is and then, is continuously performed.
Hence, an "inert solvent" means the one which is not reacted with any reactants obtained from the polymerization or hydrogenation. Such inert solvent includes the following: aliphatic hydrocarbons such as n-pentane, n-hexane, n-hepane and n-octane; aliphatic-cyclic hydrocarbons such as cyclohexane and cycloheptane; ethers such as diethylether and tetrahydrofuran. The above solvent may be employed in a single or mixed form. Further, aromatic hydrocarbons(e.g., benzene, toluene, xylene, and ethylbenzene) may be also applicable unless it hydrogenates the aromatic double bonds under predetermined hydrogenation conditions.
The hydrogenation of this invention is performed, when the content of the living polymer is in the range of 1 to 50% by the weight to a solvent, preferably in the range of 5 to 25% by the weight.
Meantime, the hydrogenation of this invention is performed in such a manner that the polymer solution is maintained at constant temperature under hydrogen or inert atmosphere and then, a hydrogenation catalyst represented by the formula I is added to the polymer in a stirred or unstirred state, and followed by input of hydrogen gas under constant pressure.
Hence, helium, nitrogen, or argon is used for inert atmosphere. These gases are not reacted with any reactants produced from the hydrogenation; since air or oxygen,which oxidizes or degrades the catalyst, induces the reduction of its activity such gas is not preferred for use.
In line with the hydrogenation of this invention, the reaction temperature is generally in the range of 0 to 150° C. If the hydrogenation temperature is lower than 0° C., the hydrogen process proves to be uneconomical in that the reduced catalytic activity including slower hydrogenation rate requires a large amount of catalyst. Further, the insolubility of the hydrogenated polymer may easily induce the precipitation of polymer. By contrast, if the hydrogenation temperature is higher than 150° C., this may result in reducing the catalytic activity and inducing the gelation or degrading the polymer. Further, with the addition of hydrogen to aromatic double bonds, the selectivity of hydrogenation is liable to be reduced. Therefore, the preferred reaction temperature is in the range of 50 to 140° C.
The pressure of hydrogen used in the hydrogenation is not specifically limited but an appropriate pressure of hydrogen is in the range of 1 to 100 kg.f/cm 2 . If the pressure is lower than 1 kg.f/cm 2 , the hydrogenation rate becomes slow and in case of higher than 100 kg.f/cm 2 , unnecessary gelation is actually induced.
Therefore, it is preferred to maintain the pressure of hydrogen in the range of 2 to 30 kg.f/cm 2 . In a correlation with hydrogenation conditions such as catalyst amounts, an optimal pressure of hydrogen is selected. Actually, it is preferred that when the amount of hydrogenation catalyst is small, the pressure of hydrogen should be high.
Meantime, as for the hydrogenation of this invention, the hydrogenation time is generally several seconds to 100 hours. The hydrogenation time may be properly selected in the above range, in the same manner as do in any reaction conditions.
According to this invention, either batch or continuous-type hydrogenation may be used.
The hydrogenation may be monitored by examining the hydrogen absorption amount.
When the unsaturated double bonds of conjugated diene polymer is hydrogenated in the presence of a hydrogenation catalyst according to this invention, more than 50% of unsaturated double bonds may be hydrogenated in a conjugated diene unit of polymer; preferably, more than 90% of unsaturated double bonds may be achieved.
More preferably, if a copolymer consisting of conjugated dienes and vinyl-substituted aromatic hydrocarbons is hydrogenated, more than 90% of hydrogenation yield may be obtained on the unsaturated double bonds of conjugated diene unit and at the same time, a hydrogenated copolymer having less than 5% hydrogenation yield in aromatic double bonds may selectively be attained.
This invention is explained in more detail by the following examples as set forth hereunder but is not limited by these examples.
PREPARATION EXAMPLE 1
Synthesis of bis(cyclopentadienyl)-bis(thienyl)titanium catalyst
A mixture of 2.5 g of 10 mmol titanocendichloride(Cp 2 TiCl 2 ) and 50 ml of tetrahydrofuran was charged to a 200 ml schienk reactor under inert gas atmosphere and the temperature was lowered to -10° C., while stirring the mixture.
20 mmol of thienyl lithium solution(in 1.0M tetrahydrofliran solution)was added slowly to the mixture and reacted for 30 minutes, while stirring it at -10° C.
Then, the solution was left at room temperature for 1 hour, and solvents were removed using a vacuum pump. With the addition of diethyl ether, the solid residues in the reactor were dissolved for filtration thereof.
The ether solution was dried using the vacuum pump to obtain a red solid as a final product.
This product was analyzed using 1 H-NMR. Yield: 80%;. 1 H-NMR(CDCl 3 ) δ(ppm):6.44(C 5 H 5 ,5H,s), 6.66(2H,d), 6.87(2H,d,d), 7.35(2H,d)
PREPARATION EXAMPLE 2
Synthesis of styrene-butadiene-styrene block copolymer
4,800 g of cyclohexane was charged to a 10 l autoclave and with the addition of 11 g of tetrahydrofuran, 124 g of styrene monomer and 16 mmol of n-butyl lithium, the mixture was under polymerization for 30 minutes.
Then, 552 g of 1,3-butadiene monomer was added to the reactor to polymerize the mixture for 1 hour.
Finally following the addition of 124 g of styrene monomer, the mixture was polymerized for 30 minutes to obtain a styrene-butadiene-styrene block copolymer with the following properties: combined styrene content: 31.0%(block styrene content: 30.0%): combined 1,2-vinyl content as butadiene unit: 38.5%(26.6% to total polymer): number-average molecular weight: about 50,000.
PREPARATION EXAMPLE 3
Synthesis of styrene-butadiene-styrene block copolymer
4,800 g of cyclohexane was charged to a 10 l autoclave and with the addition of 11 g of tetrahydrofuran, 124 g of styrene monomer and 13.3 mmol of n-butyl lithium, the mixture was under polymerization for 30 minutes. Then, 552 g of 1,3-butadiene monomer was added to the reactor to polymerize the mixture for 1 hour.
Finally, following the addition of 124 g of styrene monomer, the mixture was polymerized for 30 minutes to obtain a styrene-butadiene-styrene block copolymer with the following properties: combined styrene content: 30.9%(block styrene content: 30.0%): combined 1,2-vinyl content as butadiene unit: 38.2%(26.4% to total polymer); number-average molecular weight: about 60,000.
PREPARATION EXAMPLE 4
Synthesis of styrene-butadiene-styrene block copolymer
4,800 g of cyclohexane was charged to a 10 l autoclave and with the addition of 11 g of tetrahydrofuran, 124 g of styrene monomer and 20.0 mmol of n-butyl lithium, the mixture was under polymerization for 30 minutes. Then, 552 g of 1,3-butadiene monomer was added to the reactor to polymerize the mixture for 1 hour.
Finally, following the addition of 124 g of styrene monomer, the mixture was polymerized for 30 minutes to obtain a styrene-butadiene-styrene block copolymer with the following properties: combined styrene content: 30.7%(block styrene content: 29.9%): combined 1,2-vinyl content as butadiene unit: 39.0%(26.9% to total polymer): number-average molecular weight: about 40,000.
PREPARATION EXAMPLE 5
Synthesis of conjugated diene homopolymer
A mixture of 4,800 g of cyclohexane and 800 g of 1,3-butadiene monomer was charged to 10 l autoclave and with the addition of 20.0 mmol of n-butyl lithium, the mixture was under polymerization for 1 hour. After 1 -hour reaction was completed, a butadiene polymer was obtained with the following properties: combined 1,2-vinyl content as butadiene unit: 14.0%, cis content: 35.0%, and number-average molecular weight: about 40,000.
EXAMPLE 1
2,800 g of the solution, containing 400 g of the polymer obtained from the preparation example 2, was charged to a 5 l autoclave and heated to 60 l under stirring.
Then, 1.6 mmol of the catalyst obtained from the preparation example 1 was added to the polymer solution and under 10 kg.f/cm 2 of pressure, hydrogenation was continued for 60 minutes.
After the reaction was completed, the reactor was cooled, and the pressure was lowered to atmospheric pressure. The reacting solution was added to methanol to precipitate the polymer.
1 H-NMR analysis on hydrogenated polymer, so obtained shows that the final hydrogenation yield on butadiene unit was 90.4%, while no hydrogenation on styrene unit was observed.
EXAMPLE 2
2,800 g of the solution, containing 400 g of the polymer obtained from the preparation example 3, was charged to a 5 l outoclave and heated at 400 rpm at 60° C. Then, 2.0 mmol of the catalyst obtained from the preparation example 1 was added to the polymer solution and under 10 kg.f/cm 2 of pressure of hydrogen, hydrogenation was continued for 60 minutes.
After the reaction was completed, the reactor was cooled, and the pressure was lowered to atmospheric pressure. The reacting solution was added to methanol to precipitate the polymer.
1 H-NMR analysis on hydrogenated polymer, so obtained shows that the final hydrogenation on styrene unit was observed.
EXAMPLE 3
2,800 g of the solution, containing 400 g of the polymer obtained from the preparation example 4, was charged to a 1 l autoclave and heated at 400 rpm at 60° C. Then, 2.0 mmol of the catalyst obtained from the preparation example 1 was added to the polymer solution and under 15 kg.f/cm 2 of pressure of hydrogen, hydrogenation was continued for 60 minutes.
After the reaction was completed, the reactor was cooled, and the pressure was lowered to atmospheric pressure. The reacting solution was added to methanol to precipitate the polymer.
1 H-NMR analysis on hydrogenated polymer, so obtained shows that the final hydrogenation rate on butadiene unit was 99.2%, while no hydrogenation on styrene unit was observed.
EXAMPLE 4
2,800 g of the solution, containing 400 g of the polymer obtained from the preparation example 5, was charged to a 1 l autoclave and heated at 400 rpm at 60° C. Then, 4.0 mmol of the catalyst obtained from the preparation example 1 was added to the polymer solution and under 15 kg.f/cm 2 of pressure of hydrogen, hydrogenation was continued for 90 minutes.
After the reaction was completed, the reactor was cooled, and the pressure was lowered to atmospheric pressure. The reacting solution was added to methanol to precipitate the polymer.
1 H-NMR analysis on hydrogenated polymer, so obtained shows that the final hydrogenation rate on butadiene unit was 98.1%.
COMPARATIVE EXAMPLE 1
2,800 g of the solution, containing 400 g of the polymer obtained from the preparation example 4, was charged to a 1 l autoclave and heated at 400 rpm at 60° C.
2.0 mmol of Cp 2 TiCl 2 , a catalyst which was disclosed in the U.S. Pat. No. 4,501,857, was added to the polymer solution together with 10 mmol of n-butyl lithium. Under 1 kg.f/cm 2 of pressure of hydrogen, hydrogenation was continued for 60 minutes.
After the reaction was completed, the reactor was cooled, and the pressure was lowered to atmospheric pressure. The reacting solution was added to methanol to precipitate the polymer.
1 H-NMR analysis on hydrogenated polymer, so obtained shows that the final hydrogenation rate on butadiene unit was 85.2%, while no hydrogenation on styrene unit was observed.
As mentioned in the above, this invention has the following several advantages: (a) the hydrogenation is made available under a mild condition in the presence of a high-active catalyst; (b) in particular, in line with a copolymer consisting of conjugated diene and vinyl-substituted aromatic hydrocarbon, highly selective hydrogenation may be made available on the unsaturated double bonds of conjugated diene unit; (c) since conjugated diene polymer is used as raw material in this invention, continual hydrogenation in a same reactor may be attained and at the same time, the polymer represents extremely high activity with the addition of catalyst in a small amount, and; (d) since the hydrogenation may be performed economically and easily without catalyst removal process following hydrogenation, the process of this invention is highly effective in the industrial field.
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This invention relates to a process for hydrogenating selectively the unsaturated double bonds of copolymer having the double bonds of conjugated diene unit, which has been widely used as a modifier of transparent impact-resistant resin or polyolefin, and polystyrene resin. According to this invention, the copolymer is saturated via hydrogenation in the presence of a novel homogeneous system organotitanium catalyst without a separate reducing agent, thus representing an extremely high hydrogenation yield with remarkable hydrogenation reproducibility. Hence, a compound represented by the following formula I is employed as an appropriate catalyst.
Formula I ##STR1## Wherein Cp is a cyclopentadienyl (C 5 H 5 ) group; R 1 , R 2 and R 3 are hydrogen atom or alkyl group of 1 to 3 carbon atoms; and
R 1 , R 2 and R 3 can be the same or different.
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FIELD OF THE INVENTION
The present invention generally relates to controlling continuous sheetmaking, and more specifically, to controlling the flow of paper stock into the headbox of a papermaking machine by using measurements of the paper stock at the wire and developing a fast speed compensation signal to control said flow.
BACKGROUND OF THE INVENTION
In the art of making paper with modern high-speed machines, sheet properties must be continually monitored and controlled to assure sheet quality and to minimize the amount of finished product that is rejected when there is an upset in the manufacturing process. The sheet variables that are most often measured include basis weight, moisture content, and caliper (i.e., thickness) of the sheets at various stages in the manufacturing process. These process variables are typically controlled by, for example, adjusting the feedstock supply rate at the beginning of the process, regulating the amount of steam applied to the paper near the middle of the process, or varying the nip pressure between calendaring rollers at the end of the process. Papermaking devices well known in the art are described, for example, in "Handbook for Pulp & Paper Technologists" 2nd ed., G. A. Smook, 1992, Angus Wilde Publications, Inc., and "Pulp and Paper Manufacture" Vol III (Papermaking and Paperboard Making), R. MacDonald, ed. 1970, McGraw Hill. Sheetmaking systems are further described, for example, in U.S. Pat. Nos. 5,539,634, 5,022,966 4,982,334, 4,786,817, and 4,767,935.
In the manufacture of paper on continuous papermaking machines, a web of paper is formed from an aqueous suspension of fibers (stock) on a traveling mesh wire or fabric and water drains by gravity and vacuum suction through the fabric. The web is then transferred to the pressing section where more water is removed by dry felt and pressure. The web next enters the dryer section where steam heated dryers and hot air completes the drying process. The papermaking machine is essentially a de-watering, i.e., water removal, system. In the sheetmaking art, the term machine direction (MD) refers to the direction that the sheet material travels during the manufacturing process, while the term cross direction (CD) refers to the direction across the width of the sheet which is perpendicular to the machine direction.
Conventional methods for controlling the basis weight of the paper produced include regulating the paper stock flow rate from the stuff box through a basis weight or thick stock valve into the headbox. The valve is actuated in response to measurements of the paper just before the reel. The ability of this technique to smooth out disturbances however is limited due to the long time lags through the machine from the thick stock valve to the reel.
SUMMARY OF THE INVENTION
The present invention is based in part on the recognition that significant improvements in the control of the papermaking process can be achieved by diverting a portion of the stock flow from the stuff box to the headbox through a second line that is regulated by a second valve (e.g., vernier valve). The second valve is actuated in response to measurements of the basis weight of the wet stock at the wire. In a preferred embodiment, the wet stock basis weight measurements are made with an underwire water weight sensor (referred to herein as the "UW 3 " sensor) which is sensitive to three properties of materials: the conductivity or resistance, the dielectric constant, and the proximity of the material to the UW 3 sensor. Depending on the material being measured, one or more of these properties will dominate.
In a preferred embodiment, a plurality of UW 3 sensors are positioned underneath the wire of a papermaking machine to measure the conductivity of the aqueous wet stock. In this case, the conductivity of the wet stock is high and dominates the measurement of the UW 3 sensor. The conductivity of the wet stock is directly proportional to the total water weight within the wet stock, consequently the sensor provides information which can be used to monitor and control the quality of the paper sheet produced.
In one aspect, the invention is directed to a sheetmaking system having a wet end and a dry end wherein the wet end includes a headbox through which wet stock is discharged onto a water permeable moving wire, said system including:
a source of wet stock from which wet stock is introduced into the headbox through a first line and a second line;
a first controllable stock valve that regulates flow through the first line;
a second controllable stock valve that regulates flow through the second line;
a first control loop including means for obtaining basis weight measurements within said dry end and means for performing coarse adjustments to the first controllable stock valve in response to said dry end basis weight measurements, said first control loop having an associated first response time; and
a second control loop including means for obtaining basis weight basis weight measurements within said wet end and means for performing fine adjustments to said the second controllable stock valve in response to said wet end basis weight measurements, said second control loop having an associated second response time.
In another aspect, the invention is directed to a method for controlling a sheetmaking system having a source of wet stock that is connected to a headbox through a first line and a second line and having a wet end and a dry end, with the first line having a first controllable stock valve that regulates flow through the first line and the second line having a second controllable stock valve that regulates flow through the second line, and wherein the wet stock is discharged through the headbox onto a water permeable wire, said method including the steps of:
(a) implementing a first control loop having an associated first response time by performing at least the steps of:
(i) obtaining basis weight measurements within said dry end; and
(ii) performing coarse adjustments to first controllable stock valve in response to said dry end basis weight measurements; and
(b) implementing a second control loop having an associated second response time by performing at least the steps of:
(i) obtaining basis weight measurements within said wet end; and
(ii) performing fine adjustments to the second controllable stock valve in response to said wet end basis weight measurements.
In a further aspect, the invention is directed to a sheetmaking system that forms a sheet of wet stock on a moving water permeable wire and having a wet end and a dry end, and having a source of wet stock that is connected to a headbox through a first line, said system including:
means for measuring the basis weight within the dry end and generating first signals indicative of the dry end basis weight;
means for diverting a portion of wet stock flow from the source of wet stock through a second line having a second control valve that regulates flow through the second line and into the headbox;
a sensor positioned underneath and adjacent to the wire for measuring the basis weight of the wet stock and which generates second signals indicative of the wet end basis weight, said sensor being positioned downstream from a dry line which develops during operation of the system;
means for adjusting the flow rate through the first line in response to the first signals; and
means for adjusting the flow rate through the second line in response to the second signals.
In yet another aspect, the invention is directed to a method of controlling the formation of a sheet of wet stock that forms on a moving water permeable wire of a de-watering machine, having a wet end and a dry end, that has a source of wet stock that is connected to a headbox through a first line having a first control valve that regulates flow through the first line and that has means for measuring the basis weight within the dry end, said method including the steps of:
(a) diverting a portion of wet stock flow from the source of wet stock through a second line having a second control valve that regulates flow through the second line;
(b) placing a sensor underneath and adjacent to the wire and downstream from a dry line which develops during operation of the machine;
(c) operating the machine and measuring the basis weight within the dry end and generating first signals indicative of the dry end basis weight and measuring the basis weight with the sensor and generating second signals indicative of the wet end basis weight;
(d) adjusting the flow rate through the first line in response to the first signals; and
(e) adjusting the flow rate through the second line in response to the second signals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a basic block diagram of the under wire water weight (UW 3 ) sensor and FIG. 1B shows the equivalent circuit of the sensor block.
FIG. 2A shows a sheetmaking system implementing the technique of the present invention and FIG. 2B is a generalized block diagram of the control system.
FIG. 3 shows a block diagram of the UW 3 sensor including the basic elements of the sensor.
FIG. 4A shows an electrical representation of an embodiment of the UW 3 sensor.
FIG. 4B shows a cross-sectional view of a cell used within the UW 3 sensor and its general physical position within a sheetmaking system in accordance with one implementation of the sensor.
FIG. 5A shows a second embodiment of the cell array used in the UW 3 sensor.
FIG. 5B shows the configuration of a single cell in the second embodiment of the cell array shown in FIG. 5A.
FIG. 6A shows a third embodiment of the cell array used in the UW 3 sensor.
FIG. 6B shows the configuration of a single cell in the third embodiment of the cell array shown in FIG. 6A.
FIG. 7 is a graph of water weight versus wire position of a papermaking machine.
FIG. 8 is a graph of freeness versus wire position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention employs a system that includes one or more sensors that measure the basis weight of paper stock on the web or wire of a papermaking machine, e.g., fourdrinier. These sensors preferably are UW 3 sensors which have a very fast response time (1 msec) so that an essentially instantaneous profile of the basis weight can be obtained. Although the invention will be described as part of a fourdrinier papermaking machine, it is understood that the invention is applicable to other papermaking machines including, for example, twin wire and multiple headbox machines and to paper board formers such as cylinder machines or Kobayshi Formers. Some conventional elements of a papermaking machine are omitted in the following disclosure in order not to obscure the description of the elements of the present invention.
FIG. 2A shows a system for producing continuous sheet material that comprises processing stages including headbox 1, web or wire 7, dryer 2, calendaring stack 3, and reel 4. Actuators (not shown) in headbox 1 discharge wet stock (e.g., pulp slurry) through a plurality of slices 11 onto supporting wire 7 which rotates between rollers 5 and 6. Foils and vacuum boxes (not shown) remove water, commonly known as "white water", from the wet stock on the wire into wire pit 8 for recycle. A scanning sensor 14 continuously traverses the finished sheet (e.g., paper) and measures properties of the finished sheet. Multiple stationary sensors could also be used. Scanning sensors are known in the art and are described, for example, in U.S. Pat. Nos. 5,094,535, 4,879,471, 5,315,124, and 5,432,353, which are incorporated herein. The finished sheet is then collected on reel 4. As used herein, the "wet end" portion of the system depicted in FIG. 2A comprises the headbox, the web, and those sections just before the dryer, and the "dry end" comprises the sections that are downstream from the dryer.
The system further includes means for measuring the basis weight of the sheet of wet stock on the wire. A preferred device is the UW 3 sensor which is employed singly or in combination. In one embodiment an array of UW 3 sensors is positioned under the wire either in the CD or MD position. For instance, the basis weight at the wet end can be measured with a CD array 12 of the UW 3 sensors that is positioned underneath wire 7. By this is meant that each sensor is positioned below a portion of the wire which supports the wet stock. As further described herein, each of the sensors is configured to measure the water weight of the sheet material as it passes over the array. The array provides a continuous measurement of the entire sheet material along the CD direction at the point where it passes the array. A profile made up of a multiplicity of water weight measurements at different locations in the CD is developed. In one embodiment, an average of these measurements is obtained and converted to the wet end basis weight.
Alternatively, an MD array comprised of three UW 3 sensors 9A, 9B, and 9C is positioned underneath wire 7. A water weight profile made up of a multiplicity of water weight measurements at different locations in the MD is developed. The array should have a minimum of 3 sensors. Typically 4 to 6 sensors are employed in tandem and positioned approximately 1 meter from the edge of the wire. Typically, the sensors are positioned about 30 to 60 cm apart from each other. Both the CD and MD array sensors are preferably positioned upstream from a dry line that forms at position 10 on the wire.
The term "water weight" refers to the mass or weight of water per unit area of the wet paper stock which is on the wire. Typically, the UW 3 sensors when positioned under the wire are calibrated to provide engineering units of grams per square meter (gsm). As an approximation, a reading of 10,000 gsm corresponds to paper stock having a thickness of 1 cm on the fabric. The term "basis weight" or "BW" refers to the total weight of the material per unit area. The term "dry weight" or "dry stock weight" refers to the weight of a material (excluding any weight due to water) per unit area.
Typically, the papermaking furnish or raw material is metered, diluted, mixed with any necessary additives, and finally screened and cleaned as it is introduced into headbox 1 from fan pump 50. Specifically, although stock from machine chest 54 should be reasonable free from impurities, paper machine approach systems usually utilize pressure screens 51 and centrifugal cleaners 52 to prevent contamination.
Fan pump 50 serves to mix the stock with the white water and deliver the blend to the headbox 1. To ensure a uniform dispersion to the headbox, the stock is fed from a constant head tank 53, commonly called the "stuff box," through a first line 55A that is regulated by first control valve 55B (also called the basis weight valve) and through a second line 56A that is regulated by second control valve 56B (e.g., vernier valve). Typically, the first line 56A will accommodate at least about 70% to 80% by weight of the stock from the stuff box and can be 90% or more with the remainder going through the second line 56A. The first control valve 55B is controlled by a first controller 65 that is responsive to BW measurements performed at the dry end and the second control valve 56B is controlled by a second controller 66 that is responsive to BW measurements at the wet end.
The UW 3 sensor detects changes in properties of the material being sensed via electrical signal measurements. The second controller 66 correlates the detected electrical measurements to changes in wet BW which are then correlated to changes in dry weight and finally to a fine control signal for controlling the second valve 56B.
Dry end BW measurements can be performed using scanning sensor 14 or using a UW 3 sensor. When the UW 3 sensor is employed, it is positioned next to the reel and underneath the paper. The UW 3 sensor would be measuring the dielectric constant of the paper. When using either a scanning or UW 3 sensor, the detected electrical signals from the sensor is correlated to a dry end BW measurement and then to a coarse control signal for controlling the first valve 55B. As is apparent, the dry end BW is essentially equal to the dry weight of the paper produced.
The control system is illustrated in FIG. 2B. With respect to the outer control loop, for the paper that is produced, its basis weight is influenced by the dry end process 87 as well as by disturbances in the dry end which are represented by D 2 . The fluctuation in the basis weight of the paper is therefore represented as the sum of fluctuations in the dry process 87A and D 2 at summer 88. The dry end process experiences large delays of 3 to 4 minutes for example. The basis weight is continuously measured by the scanning sensor 89 located next to the reel 70. The scanning sensor transmits signals 89A which are representative of the measured basis weight to comparator 90 which also receives input signal 90A that introduces the basis weight set point. Any difference between the incoming signals delivered appears as an error signal 90B from the comparator to a primary basis weight controller 91, e.g., Dahlin controller, that produces valve control signal 91A to controller 92 which converts the input signal 91A into the predicted basis weight at the wire via a transfer function (k) for example, which information 92A is then transmitted to comparator 85.
With respect to the inner control loop, the water weight of the paper stock is influenced by the wet end process 82 as well as by disturbances in the wet end which are represented by D 1 . The wet end process experiences only small transient delays of 15 to 30 seconds for example. The fluctuation in the water weight of the paper is therefore represented as the sum of fluctuations in the wet process 82A and D 1 at summer 83. The water weight of the paper stock at the wire is continuously measured with sensors 84 and the measurements therefrom are used to calculate the anticipated basis weight on the wire which is represented by signal 84A which is transmitted to comparator 85.
Any differences between the predicted basis weight at the wire signal 92A and the anticipated basis weight signal 84A appears as an error signal to the secondary basis weight controller 80, e.g., proportional integral differential controller or Dahlin controller. The secondary basis weight controller transmits signal 80A that activates divert valve 81 to increase or decrease the flow rate of wet stock into the headbox from the stuff box. Controller 80 converts the basis weight error signal from comparator 85 into valve movement signals.
As is apparent, disturbances within the fast inner control loop are corrected by the fast inner loop controller based on water weight measurements on the wire before the disturbances can affect the thick stock valve 86 of the slower outer control loop. Stock valve 86 receives signals from controller 98 which performs a transfer function (1/k) that converts signals from summer 83 that represent the predicted basis weight to valve movement signals 98A.
In addition, the closed loop response of the outer control loop is influenced by the dynamics of the inner control loop. Therefore, the faster the vernier valve 81 can respond and the faster water weight measurement is achieved, the less the outer control loop will need to act on thick stock valve 86 to correct variations as indicated by measurements by the scanning sensor 89.
Furthermore, if the dynamics of the inner control loop are faster, the phase lag of the inner control loop is less than that of the outer control loop. Consequently, the crossover frequency for the inner control loop is higher than that of the outer control loop. This means that the larger gains of the inner controller can be employed to more effectively regulate the effect of a disturbance occurring in the inner control loop, i.e., wet end, without endangering the stability of the basis weight controller. So, rather than having one controller designed to ensure stability, the inventive process employs a fast inner controller rejecting wet end disturbances and a slower outer controller ensuring that the operation is in range.
When employing the MD array of UW 3 sensors to provide fast control of first control valve 55B (e.g., venier valve), it is preferred to formulate a functional relationship between water weight measurements from the UW 3 sensors for a segment of moving wet stock on the wire and the predicted moisture level for the segment after being substantially de-watered, i.e., its dry end basis weight. The modeling technique is described herein and in U.S. patent application Ser. No. 08/789,086 filed on Jan. 27, 1997 which is incorporated herein.
The functional relationship allows water weight measurements for a segment on the wire made by the UW 3 sensors to be employed to predict what the dry basis weight or dry stock weight would be when the segment reaches the dry end. In this fashion, the UW 3 sensor measurements can be converted into dry basis weights that are compared to the target setting to obtain the error, if any.
Predicting Dry End Basis Weight From Measurements of UW 3 Sensors
A preferred method of predicting the dry end basis or stock weight of the paper produced involves simultaneous measurements of (1) the water contents of the paper stock on the fabric or wire of the papermaking machine at three or more locations along the machine direction of the fabric and of (2) the dry stock weight of the paper product preceding the paper stock on the fabric. In this fashion, the expected dry stock weight of the paper that will be formed by the paper stock on the fabric can be determined at that instance.
Specifically, the method of predicting the dry stock weight of a sheet of material that is moving on the water permeable wire of the above-described system includes the following steps:
a) placing three or more water weight sensors adjacent to the wire wherein the sensors are positioned at different locations in the MD and placing a sensor to measure the moisture content of the sheet of material after being substantially de-watered (this would be the scanning sensor);
b) operating the system at predetermined operating parameters and measuring the water weights of the sheet of material at the three or more locations on the wire with the water weight sensors and simultaneously measuring the dry basis weight of a part of the sheet of material that has been substantially de-watered;
c) performing bump tests to measure changes in water weight in response to perturbations in three or more operating parameters wherein each bump test is performed by alternately varying one of the operating parameters while keeping the others constant, and calculating the changes in the measurements of the three or more water weight sensors and wherein the number of bump tests correspond to the number of water weight sensors employed;
d) using said calculated changes in the measurements from step c) to obtain a linearized model describing changes in the three or more water weight sensors as a function of changes in the three or more operating parameters about said predetermined operating parameters wherein this function is expressed as an N×N matrix wherein N is equal to the number of water weight sensors employed; and
e) developing a functional relationship between water weight measurements from the three or more water weight sensors for a segment of the moving sheet of material at the fabric and the predicted moisture level for the segment after being substantially de-watered.
Preferably, the bump tests comprise varying the flow rate of the aqueous fiber stock onto the fabric, freeness of the fiber stock, and concentration of fiber in the aqueous fiber stock. By continuously monitoring the water weight levels of the paper stock on the fabric, it is possible to predict the quality (i.e., dry stock weight) of the product.
The water drainage profile on a fourdrinier wire is a complicated function principally dependent on the arrangement and performance of drainage elements, characteristics of the wire, tension on the wire, stock characteristics (for example freeness, pH and additives), stock thickness, stock temperature, stock consistency and wire speed. It has demonstrated that particularly useful drainage profiles can be generated by varying the following process parameters: 1) total water flow which depends on, among other things, the headbox delivery system, head pressure and slice opening and slope position; 2) freeness which depends on, among other things, the stock characteristics and refiner power; and 3) dry stock flow and headbox consistency.
Water weight sensors placed at strategic locations along the papermaking fabric can be used to profile the de-watering process (hereinafter referred to as "drainage profile"). By varying the above stated process parameters and measuring changes in the drainage profile, one can then construct a model which simulates the wet end paper process dynamics. Conversely one can use the model to determine how the process parameters should be varied to maintain or produce a specified change in the drainage profile. Furthermore the dry stock weight of the web on the wire can be predicted from the water weight drainage profiles.
Three water weight sensors 9A, 9B, and 9C are illustrated to measure the water weight of the paper stock on the wire. The position along the fabric at which the three sensors are located are designated "h", "m", and "d", respectively. More than three water weight sensors can be employed. It is not necessary that the sensors be aligned in tandem, the only requirement is that they are positioned at different machine directional positions. Typically, readings from the water weight sensor at location "h" which is closest to the headbox will be more influenced by changes in stock freeness than in changes in the dry stock since changes in the latter is insignificant when compared to the large free water weight quantity. At the middle location "m", the water weight sensor is usually more influenced by changes in the amount of free water than by changes in the amount of dry stock. Most preferably location "m" is selected so as to be sensitive to both stock weight and free changes. Finally, location "d", which is closest to the drying section, is selected so that the water weight sensor is sensitive to changes in the dry stock because at this point of the de-water process the amount of water bonded to or associated with the fiber is proportional to the fiber weight. This water weight sensor is also sensitive to changes in the freeness of the wire although to a lesser extent. Preferably, at position "d" sufficient amounts of water have been removed so that the paper stock has an effective consistency whereby essentially no further fiber loss through the fabric occurs.
In measuring paper stock, the conductivity of the mixture is high and dominates the measurement of the sensor. The conductivity of the paper stock is directly proportional to the total water weight within, consequently providing information which can be used to monitor and control the quality of the paper sheet produced by the papermaking system. In order to use this sensor to determine the weight of fiber in a paper stock mixture by measuring its conductivity, the paper stock is in a state such that all or most of the water is held by the fiber. In this state, the water weight of the paper stock relates directly to the fiber weight and the conductivity of the water weight can be measured and used to determine the weight of the fiber in the paper stock.
To implement this technique, three water weight sensors are used to measure the dependence of the drainage profile of water from the paper stock through the wire on three machine operation parameters: (1) total water flow, (2) freeness of paper stock, and (3) dry stock flow or headbox consistency. Other applicable parameters include for example, (machine speed and vacuum level for removing water). For the case of three process parameters the minimum is three water weight sensors. More can be used for more detailed profiling.
A preferred form of modeling uses a baseline configuration of process parameters and resultant drainage profile, and then measures the effect on the drainage profile in response to a perturbation of an operation parameter of the fourdrinier machine. In essence this linearizes the system about the neighborhood of the baseline operating configuration. The perturbations or bumps are used to measure first derivatives of the dependence of the drainage profile on the process parameters.
Once a set of drainage characteristic curves has been developed, the curves, which are presented as a 3×3 matrix, can be employed to, among other things, predict the water content in paper that is made by monitoring the water weight along the wire by the water weight sensors. This information is employed to control the vernier valve.
Bump Tests
The term "bump test" refers to a procedure whereby an operating parameter on the papermaking machine is altered and changes of certain dependent variables resulting therefrom are measures. Prior to initiating any bump test, the papermaking machine is first operated at predetermined baseline conditions. By "baseline conditions" is meant those operating conditions whereby the machine produces paper. Typically, the baseline conditions will correspond to standard or optimized parameters for papermaking. Given the expense involved in operating the machine, extreme conditions that may produce defective, non-useable paper is to be avoided. In a similar vein, when an operating parameter in the system is modified for the bump test, the change should not be so drastic as to damage the machine or produce defective paper. After the machine has reached steady state or stable operations, the water weights at each of the three sensors are measured and recorded. Sufficient number of measurements over a length of time are taken to provide representative data. This set of steady-state data will be compared with data following each test. Next, a bump test is conducted. The following data were generated on a Beloit Concept 3 papermaking machine, manufactured by Beloit Corporation, Beloit, Wis. The calculations were implemented using a microprocessor using Labview 4.0.1 software from National Instrument (Austin Tex.).
(1) Dry stock flow test. The flowrate of dry stock delivered to the headbox is changed from the baseline level to alter the paper stock composition. Once steady state conditions are reached, the water weights are measured by the three sensors and recorded. Sufficient number of measurements over a length of time are taken to provide representative data. FIG. 7 is a graph of water weight vs. wire position measured during baseline operations and during a dry stock flow bump test wherein the dry stock was increase by 100 gal/min from a baseline flow rate of 1629 gal/min. Curve A connects the three water weight measurements during baseline operations and curve B connects the measurements during the bump test. As is apparent, increasing the dry stock flow rate causes the water weight to increase. The reason is that because the paper stock contains a high percentage of pulp, more water is retained by the paper stock. The percentage difference in the water weight at positions h, m, and d (corresponding to sensors 9A, 9B and 9C, respectively, in FIG. 2) along the wire are +5.533%, +6.522%, and +6.818%, respectively.
For the dry stock flow test, the controls on the papermaking machine for the basic weight and moisture are switched off and all other operating parameters are held as steady as possible. Next, the stock flow rate is increased by 100 gal/min. for a sufficient amount of time, e.g., about 10 minutes. During this interval, measurements from the three sensors are recorded and the data derived therefrom are shown in FIG. 7.
(2) Freeness test. As described previously, one method of changing the freeness of paper stock is to alter the power to the refiner which ultimately effects the level of grinding the pulp is subjected to. During the freeness test, once steady state conditions are reached, the water weights at each of the three sensors are measured and recorded. In one test, power to the refiner was increased from about 600 kw to about 650 kw. FIG. 8 is a graph of water weight vs. freeness measured during baseline operations (600 kw) (curve A) and during the steady state operations after an additional 50 kw are added (curve B). As expected, the freeness was reduced resulting in an increase in the water weight as in the dry stock flow test. Comparison of the data showed that the percentage difference in the water weight at positions h, m, and d are +4.523%, +4.658%, and +6.281%, respectively.
(3) Total paper stock flow rate (slice) test. One method of regulating the total paper stock flow rate from the headbox is to adjust aperture of the slice. During this test, once steady state conditions are reached, the water weights at each of the three sensors are measured and recorded. In one test, the slice aperture was raised from about 1.60 in. (4.06 cm) to about 1.66 in. (4.2 cm) thereby increasing the flow rate. As expected, the higher flow rate increased the water weight. Comparison of the data showed that the percentage difference in the water weight at positions h, m, and d are +9.395%, +5.5%, and +3.333%, respectively. (The measurement at position m of 5.5% is an estimate since the sensor at this location was not in service when the test was performed.)
The Drainage Characteristic Curves (DCC)
From the previously described bump tests one can derive a set of drainage characteristic curves (DCC). The effect of changes in three process parameters on the three water weight sensor values provides nine partial derivatives which form a 3×3 DCC matrix. Generally, when employing n number of water weight sensors mounted on the wire and m bump tests, a n×m matrix is obtained.
Specifically, the 3×3 DCC matrix is given by:
DC.sub.The DC.sub.Tm DC.sub.Td
DC.sub.Fh DC.sub.Fm DC.sub.Fd
DC.sub.Sh DC.sub.Sm DC.sub.Sd
where T, F, S refer to results from bumps in the total water flow, freeness, and dry stock flow, respectively, and h, m, and d designate the positions of the sensors mounted along the wire or fabric.
The matrix row components DC The DC Tm DC Td ! are defined as the percentage of water weight change on total water weight at locations h, m, and d based on the total flow rate bump tests. More precisely, for example, "DC The " is defined as the difference in percentage water weight change at position h at a moment in time just before and just after the total flow rate bump test. DC Tm and DC Td designate the values for the sensors located at positions m and d, respectively. Similarly, the matrix row components DC Fh DC Fm DC Fd ! and
DC Sh DC Sm DC Sd ! are derived from the freeness and dry stock bump tests, respectively.
Components DC The , DC Fm and DC Sd on the DDC matrix are referred to pivotal coefficients and by Gauss elimination, for example, they are used to identify the wet end process change as further described herein. If a pivot coefficient is too small, the uncertainty in the coefficients will be amplified during the Gauss elimination process. Therefore, preferably these three pivotal coefficients should be in the range of about 0.03 to 0.10 which corresponds to about 3% to 10% change in the water weight during each bump test.
Drainage Profile Change
Based on the DCC matrix, the drainage profile change can be represented as a linear combination of changes in the different process parameters. Specifically, using the DCC matrix, the percentage change in the drainage profile at each location may be computed as a linear combination of the individual changes in the process parameters: total water flow, freeness, and dry stock flow. Thus:
ΔDP % (h,t)=DCTh*w+DCFh*ƒ+DCSh*s,
ΔDP % (m,t)=DCTm*w+DCFm*ƒ+DCSm*s,
ΔDP % (d,t)=DCTd*w+DCFd*ƒ+DCSd*s,
where (wwhere (w, ƒ, s) refer to changes in total water flow, freeness, and dry stock flow respectively, and the DC's are components of the DCC matrix.
By inverting this system of linear equations, one may solve for the values of (w, ƒ, s) needed to produce a specified drainage profile change (ΔDP % (h), ΔDP % (m), ΔDP % (d). Letting A represent the inverse of the DCC matrix, ##EQU1##
The above equation shows explicitly how inverting the DCC matrix allows one to compute the (w, ƒ, s) needed to effect a desired change in drainage profile, (ΔDP % (h), ΔDP % (m), ΔDP % (d)).
Empirically, the choice of the three operating parameters, the location of the sensors, and the size of the bumps produces a matrix with well behaved pivot coefficients, and the matrix can thus be inverted without undue noise.
By continuously comparing the dry weight measurement from scanner 14 in FIG. 2 with the water weight profiles measured at sensors h, m, and d, one can make a dynamic estimate of the final dry stock weight will be for the paper stock that is at the position of scanner 14.
Dry Stock Prediction
At location d which is closest to the drying section, the state of the paper stock is such that essentially all of the water is held by the fiber. In this state, the amount of water bonded to or associated with the fiber is proportional to the fiber weight. Thus the sensor at location d is sensitive to changes in the dry stock and is particularly useful for predicting the weight of the final paper stock. Based on this proportionality relation: DW(d)=U(d)*C(d), where DW(d) is the predicted dry stock weight at location d, U(d) is the measured water weight at location d and C(d) is a variable of proportionality relating DW to U and may be referred to as the consistency. Further, C(d) is calculated from historical data of the water weight and dry weight measured by the scanning sensor at reel-up.
Subsequent to position d (9C) in the papermaking machine (see FIG. 2A), the sheet of stock is dried and scanning sensor 14 measures the final dry stock weight of the paper product. Since there is essentially no fiber loss subsequent to location d, it may be assumed that DW(d) is equal to the final dry stock weight and thus one can calculate the consistency C(d) dynamically.
Having obtained these relations, one can then predict the effect of changes in the process parameters on the final dry stock weight. As derived previously the DCC matrix predicts the effect of process changes on the drainage profile. Specifically in terms of changes in total water flow w, freeness ƒ, and dry stock flow s, the change in U(d) is given by:
ΔU(d)/U(d)=DC.sub.Td
where Ref(cd) is a dynamic calculated value based on current dry weight sensor and historical water weight sensory readings
where the α's are defined to be gain coefficients which were obtained during the three bump tests previously described. Finally, the perturbed dry stock weight at location d is then given by:
Dw(d)=U(d)* {1+ α.sub.T DC.sub.Td *w+α.sub.F DC.sub.Fd *ƒ+d.sub.S DC.sub.Sd *s!}Ref (c)
The last equation thus describes the effect on dry stock weight due to a specified change in process parameters. Conversely, using the inverse of the DCC matrix one can also deduce how to change the process parameters to produce a desired change in dry weight (s), freeness (f) and total water flow (w) for product optimization.
Under Wire Water Weight (UW 3 ) Sensor
In its broadest sense, the sensor can be represented as a block diagram as shown in FIG. 1A, which includes a fixed impedance element (Zfixed) coupled in series with a variable impedance block (Zsensor) between an input signal (Vin) and ground. The fixed impedance element may be embodied as a resistor, an inductor, a capacitor, or a combination of these elements. The fixed impedance element and the impedance, Zsensor, form a voltage divider network such that changes in impedance, Zsensor, results in changes in voltage on Vout. The impedance block, Zsensor, shown in FIG. 1A is representative of two electrodes and the material residing between the electrodes. The impedance block, Zsensor, can also be represented by the equivalent circuit shown in FIG. 1B, where Rm is the resistance of the material between the electrodes and Cm is the capacitance of the material between the electrodes. The sensor is further described in U.S. patent application Ser. No. 08/766,864 filed on Dec. 13, 1996, which is incorporated herein.
As described above, wet end BW measurements can be obtained with one or more UW 3 sensors. Moreover, when more than one is employed, preferably the sensors are configured in an array.
The sensor is sensitive to three physical properties of the material being detected: the conductivity or resistance, the dielectric constant, and the proximity of the material to the sensor. Depending on the material, one or more of these properties will dominate. The material capacitance depends on the geometry of the electrodes, the dielectric constant of the material, and its proximity to the sensor. For a pure dielectric material, the resistance of the material is infinite (i.e. Rm=∞) between the electrodes and the sensor measures the dielectric constant of the material. In the case of highly conductive material, the resistance of the material is much less than the capacitive impedance (i.e. Rm<<Z Cm ), and the sensor measures the conductivity of the material.
To implement the sensor, a signal Vin is coupled to the voltage divider network shown in FIG. 1A and changes in the variable impedance block (Zsensor) is measured on Vout. In this configuration the sensor impedance, Zsensor, is: Zsensor=Zfixed*Vout/(Vin-Vout) (Eq. 1). The changes in impedance of Zsensor relates physical characteristics of the material such as material weight, temperature, and chemical composition. It should be noted that optimal sensor sensitivity is obtained when Zsensor is approximately the same as or in the range of Zfixed.
Cell Array
FIG. 4A shows an electrical representation of cell array 24 (including cells 1-n) and the manner in which it functions to sense changes in conductivity of the aqueous mixture. As shown, each cell is coupled to Vin from signal generator 25 through an impedance element which, in this embodiment, is resistive element Ro. Referring to cell n, resistor Ro is coupled to the center sub-electrode 24D(n). The outside electrode portions 24A(n) and 24B(n) are both coupled to ground. Also shown in FIG. 4A are resistors Rs1 and Rs2 which represent the conductance of the aqueous mixture between each of the outside electrodes and the center electrode. The outside electrodes are designed to be essentially equidistant from the center electrode and consequently the conductance between each and the center electrode is essentially equal (Rs1=Rs2=Rs). As a result, Rs1 and Rs2 form a parallel resistive branch having an effective conductance of half of Rs (i.e. Rs/2). It can also be seen that resistors Ro, Rs1, and Rs2 form a voltage divider network between Vin and ground. FIG. 4B also shows the cross-section of one implementation of a cell electrode configuration with respect to a sheetmaking system in which electrodes 24A(n), 24B(n), and 24D(n) reside directly under the web 13 immersed within the aqueous mixture.
The sensor apparatus is based on the concept that the resistance Rs of the aqueous mixture and the weight/amount of an aqueous mixture are inversely proportional. Consequently, as the weight increases/decreases, Rs decreases/increases. Changes in Rs cause corresponding fluctuations in the voltage Vout as dictated by the voltage divider network including Ro, Rs1, and Rs2.
The voltage Vout from each cell is coupled to detector 26. Hence, variations in voltage directly proportional to variations in resistivity of the aqueous mixture are detected by detector 26 thereby providing information relating to the weight and amount of aqueous mixture in the general proximity above each cell. Detector 26 may include means for amplifying the output signals from each cell and in the case of an analog signal will include a means for rectifying the signal to convert the analog signal into a DC signal. In one implementation well adapted for electrically noisy environments, the rectifier is a switched rectifier including a phase lock-loop controlled by Vin. As a result, the rectifier rejects any signal components other than those having the same frequency as the input signal and thus provides an extremely well filtered DC signal. Detector 26 also typically includes other circuitry for converting the output signals from the cell into information representing particular characteristics of the aqueous mixture.
FIG. 4A also shows feedback circuit 27 including reference cell 28 and feedback signal generator 29. The concept of the feedback circuit 27 is to isolate a reference cell such that it is affected by aqueous mixture physical characteristic changes other than the physical characteristic that is desired to be sensed by the system. For instance, if water weight is desired to be sensed then the water weight is kept constant so that any voltage changes generated by the reference cell are due to physical characteristics other than water weight changes. In one embodiment, reference cell 28 is immersed in an aqueous mixture of recycled water which has the same chemical and temperature characteristics of the water in which cell array 24 is immersed in. Hence, any chemical or temperature changes affecting conductivity experienced by array 24 is also sensed by reference cell 28. Furthermore, reference cell 28 is configured such that the weight of the water is held constant. As a result voltage changes Vout(ref. cell) generated by the reference cell 28 are due to changes in the conductivity of the aqueous mixture, not the weight. Feedback signal generator 29 converts the undesirable voltage changes produced from the reference cell into a feedback signal that either increases or decreases Vin and thereby cancels out the affect of erroneous voltage changes on the sensing system. For instance, if the conductivity of the aqueous mixture in the array increases due to a temperature increase, then Vout(ref. cell) will decrease causing a corresponding increase in the feedback signal. Increasing Vfeedback increases Vin which, in turn, compensates for the initial increase in conductivity of the aqueous mixture due to the temperature change. As a result, Vout from the cells only change when the weight of the aqueous mixture changes.
One reason for configuring the cell array as shown in FIG. 3, with the center electrode placed between two grounded electrodes, is to electrically isolate the center electrode and to prevent any outside interaction between the center electrode and other elements within the system. However, it should also be understood that the cell array can be configured with only two electrodes. FIG. 5A shows a second embodiment of the cell array for use in the sensor. In this embodiment, the sensor includes a first grounded elongated electrode 30 and a second partitioned electrode 31 including sub-electro 32. A single cell is defined as including one of the sub-electrodes 32 and the portion of the grounded electrode 30 which is adjacent to the corresponding sub-electrode. FIG. 5A shows cells 1-n each including a sub-electrode 32 and an adjacent portion of electrode 30. FIG. 5B shows a single cell n, wherein the sub-electrode 32 is coupled to Vin from the signal generator 25 through a fixed impedance element Zfixed and an output signal Vout is detected from the sub-electrode 32. It should be apparent that the voltage detected from each cell is now dependent on the voltage divider network, the variable impedance provided from each cell and the fixed impedance element coupled to each sub-electrode 32. Hence, changes in conductance of each cell is now dependent on changes in conductance of Rs1. The remainder of the sensor functions in the same manner as with the embodiment shown in FIG. 4A. Specifically, the signal generator provides a signal to each cell and feedback circuit 27 compensates Vin for variations in conductance that are not due to the characteristic being measured.
The cells shown in FIGS. 5A and 5B may alternatively be coupled such that Vin is coupled to electrode 30 and each of sub-electrodes 32 are coupled to fixed impedance elements which, in turn, are coupled to ground.
In still another embodiment of the cell array shown in FIGS. 6A and 6B, the cell array includes first and second elongated spaced apart partitioned electrodes 33 and 34, each including first and second sets of sub-electrodes 36 and 35, (respectively). A single cell (FIG. 6B) includes pairs of adjacent sub-electrodes 35 and 36, wherein sub-electrode 35 in a given cell is independently coupled to the signal generator and sub-electrode 36 in the given cell provides Vout to a high impedance detector amplifier which provides Zfixed. This embodiment is useful when the material residing between the electrodes functions as a dielectric making the sensor impedance high. Changes in voltage Vout is then dependent on the dielectric constant of the material. This embodiment is conducive to being implemented at the dry end (FIG. 2A) of a sheetmaking system (and particularly beneath and in contact with continuous sheet 18) since dry paper has high resistance and its dielectric properties are easier to measure.
In a physical implementation of the sensor shown in FIG. 1A for performing individual measurements of more than one area of a material, one electrode of the sensor is grounded and the other electrode is segmented so as to form an array of electrodes (described in detail below). In this implementation, a distinct impedance element is coupled between Vin and each of the electrode segments. In an implementation for performing individual measurements of more than one area of a material of the sensor, the positions of the fixed impedance element and Zsensor are reversed from that shown in FIG. 1A. One electrode is coupled to Vin and the other electrode is segmented and coupled to a set of distinct fixed impedances which, in turn, are each coupled to ground. Hence, neither of the electrodes are grounded in this implementation of the sensor.
FIG. 3 illustrates a block diagram of one implementation of the sensor apparatus including cell array 24, signal generator 25, detector 26, and optional feedback circuit 27. Cell array 24 includes two elongated grounded electrodes 24A and 24B and center electrode 24C spaced apart and centered between electrodes 24A and 24B and made up of sub-electrodes 24D(1)-24D(n). A cell within array 24 is defined as including one of sub-electrodes 24D situated between a portion of each of the grounded electrodes 24A and 24B. For example, cell 2 includes sub-electrode 24D(2) and grounded electrode portions 24A(2) and 24B(2). For use in the system as shown in FIG. 2, cell array 24 resides beneath and in contact with supporting web 13 and can be positioned either parallel to the machine direction (MD) or to the cross-direction (CD) depending on the type of information that is desired. In order to use the sensor apparatus to determine the weight of fiber in a wetstock mixture by measuring its conductivity, the wetstock must be in a state such that all or most of the water is held by the fiber. In this state, the water weight of the wetstock relates directly to the fiber weight and the conductivity of the water weight can be measured and used to determine the weight of the fiber in the wetstock.
Each cell is independently coupled to an input voltage (Vin) from signal generator 25 through an impedance element Zfixed and each provides an output voltage to voltage detector 26 on bus Vout. Signal generator 25 provides Vin. In one embodiment Vin is an analog waveform signal, however other signal types may be used such as a DC signal. In the embodiment in which signal generator 25 provides a waveform signal it may be implemented in a variety of ways and typically includes a crystal oscillator for generating a sine wave signal and a phase lock loop for signal stability. One advantage to using an AC signal as opposed to a DC signal is that it may be AC coupled to eliminate DC off-set.
Detector 26 includes circuitry for detecting variations in voltage from each of the sub-electrodes 24D and any conversion circuitry for converting the voltage variations into useful information relating to the physical characteristics of the aqueous mixture. Optional feedback circuit 27 includes a reference cell also having three electrodes similarly configured as a single cell within the sensor array. The reference cell functions to respond to unwanted physical characteristic changes in the aqueous mixture other than the physical characteristic of the aqueous mixture that is desired to be measured by the array. For instance, if the sensor is detecting voltage changes due to changes in water weight, the reference cell is configured so that it measures a constant water weight. Consequently, any voltage/conductivity changes exhibited by the reference cell are due to aqueous mixture physical characteristics other than weight changes (such as temperature and chemical composition). The feedback circuit uses the voltage changes generated by the reference cell to generate a feedback signal (Vfeedback) to compensate and adjust Vin for these unwanted aqueous mixture property changes (to be described in further detail below). The non-weight related aqueous mixture conductivity information provided by the reference cell may also provide useful data in the sheetmaking process.
Individual cells within sensor 24 can be readily employed in the system of FIGS. 2A and 2B so that each of the individual cells (1 to n) corresponds to each of the individual UW 3 sensors (or elements) 9A, 9B, and 9C. The length of each sub-electrode (24D(n)) determines the resolution of each cell. Typically, its length ranges from 1 in. to 6 in.
The sensor cells are positioned underneath the web, preferably upstream of the dry line, which on a fourdrinier, typically is a visible line of demarcation corresponding to the point where a glossy layer of water is no longer present on the top of the stock.
A method of constructing the array is to use a hydrofoil or foil from a hydrofoil assembly as a support for the components of the array. In a preferred embodiment, the grounded electrodes and center electrodes each has a surface that is flushed with the surface of the foil.
It should be understood that in the case in which an array 24 of sensor cells as shown in FIG. 3 cannot be placed along the machine or cross direction of the sheetmaking system due to obstructions within the system, then individual sensor cells are positioned along the cross or machine direction of the system. Each cell can then individually sense changes in conductivity at the point at which they are positioned which can then be used to determined basis weight. As shown in FIGS. 3 and 4b a single cell comprises at least one grounded electrode (either 24A(n) or 24B(n) or both) and a center electrode 24D(n).
The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments discussed. Thus, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.
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Apparatus and process for controlling the basis weight of paper produced in a papermaking machine are provided. In the papermaking process, a major portion of the paper stock flows through a first line that is controlled by a thick stock valve and a minor portion of the stock flow from the stuff box to the headbox is diverted through a second line that is regulated by a second valve (e.g., vernier valve). The thick stock valve is controlled by the dry end basis weight and the second valve responsive to measurements of the basis weight of the wet stock at the wire. The second line and control valve along with the wet end basis weight measurements form a fine control loop with fast response time whereas the first line and control valve that is responsive to dry end basis weight measurements form a course control loop. The dual control loops enable fast and actual basis weight control.
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FIELD OF THE INVENTION
The present invention relates to an acoustic coupler system for coupling data signals such as those supplied from a modem device to a telephone line, particularly wherein a non-linear acoustic coupling transducer is employed between the modem and the telephone line.
BACKGROUND OF THE INVENTION
Present day communication systems include interface coupling arrangements wherein data signals from a modem are to be coupled to a telephone link. Desirably, the modem is to be coupled through any telephone instrument without direct connection to a telephone line. Unfortunately, the coupling transfer characteristic of a typical telephone microphone is very non-linear, which creates a severe intefacing problem in that the fidelity of signals which can be coupled from a modem to a telephone line through the standard telephone acoustic transducer device is limited. Moreover, the degree of such non-linearity is variable from telephone to telephone, and varies as a function of time for any particular instrument, so that providing a fixed compensation for the telephone instrument will not eliminate the non-linearity.
SUMMARY OF THE INVENTION
In accordance with the present invention, the above described non-linearity can be effectively eliminated by the use of a novel acoustic coupling system which imparts a variable correction signal to the telephone line signal in accordance with the degree of non-linearity being imparted by the coupling instrument.
More particularly, the present invention monitors both the data signal from the modem and the output of the acoustic coupling telephone instrument, the non-linearity of which is to be compensated. The two signals are compared and an error signal representative of the degree of non-linearity of the signal is generated. This error signal is appropriate scaled and stored in a memory as a correction signal. Stored correction signals are read out of the memory in response to the characteristics of the signals from the modem and added to these signals before they are imparted to the non-linear coupling instrument. The added correction signals effectively compensate for the non-linearity of the acoustic coupler thereby removing the unwanted distortion from the telephone line signal. The contents of the memory are dynamically adjusted so that the system effectively adapts itself to the non-linearity of the instrument.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a general configuration of an adaptive linearizing acoustic coupling system;
FIG. 2 is a schematic block diagram of a modification of the adaptive linearizing acoustic coupling system shown in FIG. 1; and
FIG. 3 is a schematic diagram of an adaptive delay employed in the modified system configuration illustrated in FIG. 2.
DETAILED DESCRIPTION
Referring now to FIG. 1, there is shown a modem 1 from which signals are to be coupled to a telephone line 2 through a standard telephone coupling instrument identified as non-linear coupler 3. Prior to entering coupler 3, digital data signals from modem 1 are combined in an adder 5 with a distortion correction signal obtained from an adaptive feedback network. The output of adder 5 is converted into an analog signal by digital to analog converter 4 for coupling to telephone coupler 3. The output of the non-linear coupler 3, which is directly linked to the telephone line 2, is monitored by a receiver coupler 11. Fortunately, the type of transducer used in the telephone receiver earpiece does not suffer from the non-linearity of the modem-to-telephone coupler so that a substantially distortion-free representation of the telephone line signal is available at the output of receiver coupler 11. The telephone line representative signal is sampled and then converted into digital form by A-D converter 12 for adjustment of the adaptive feedback network, so that successive digital samples of the telephone line signal from A-D converter 12 are supplied to one input of subtractor 13. The other input of subtractor 13 is connected to the output of the modem 1 whereby, at the output of subtractor 13, there is generated a digital error signal corresponding to the difference between the intended-to-be transmitted modem output signal and the telephone line signal which is a distorted version of the modem output (due to the non-linearity imparted by coupler 3).
The error signal output of subtractor 13 is connected to a scaler circuit 14 which adjusts the amplitude of the error signal by multiplying the error signal by an appropriate constant. The adjusted error signal for a particular telephone line signal sample is then combined in adder 15 with an error signal selectively read out of memory 16 and then returned to memory 16 as an updated representation of the correction signal to be added to the modem signal in adder 5. Memory 16 is selectively addressed by quantizing the amplitude and the rate of change of the modem output. To this end, the output of modem 1 is connected to quantizer 18 and to differentiator 17. The output of differentiator 17 is also connected to quantizer 18. The output of quantizer 18 is a digital signal which identifies an address in memory 16 from which the correction signal for the data sample of interest is to be obtained and combined with the modem output in adder 5. Quantizer 18 converts the amplitude of the output of modem 1 and the time differential of this output into respective digital bit codes which are combined to define a memory address. The upper order bits are defined by the encoded amplitude, while the lower order bits are established by encoding the output of differentiator 17. If desired, higher order differentiators may be added to further refine memory address codes.
In operation, modem signals, in digital format, are supplied to adder 5, differentiator 17, quantizer 18, and subtractor 13. Quantizer 18 generates a memory address signal based upon the characteristics of the output of modem 1 and thereby causes a correctin signal to be read out from memory 16 and supplied to adders 5 and 15. As the correction signal stored in the memory address defined by the output of quantizer 18 is being combined in adder 5 with the modem output signal, the analog value of the telephone line signal at the output of coupler 3 is sampled and converted into a digital form by A-D converter 12. Subtractor 13 generates an error signal on the basis of the difference between the value of the modem output and the digital sample of the telephone line signal, which error signal is adjusted by scaler 14 and combined with the correction signal obtained from memory 16, so that a new or updated value of the correction signal of interest is written back into the particular memory address defined by quantizer 18 on the basis of the characteristics of that particular signal sample. Thus, as the distortion characteristic of coupler 3 varies with time, the adaptive feedback network will continue to follow the changes in this characteristic and adjust the correction signal contents of memory 16 so as to compensate the modem output during successive sample intervals for the error introduced by coupler 3. In this manner, a high fidelity telephone line signal may be obtained at the output of coupler 3.
While the above description of the basic approach to storing the non-linearity problem created by coupler 3 provides an adaptive correction signal, in reality, refinement of the system is needed to offset delays in signal processing and electrical acoustic conversion, such as delays introduced in the acoustic paths by both the transmitter and receiver couplers 3 and 11, respectively. These delays result in the fact that by the time the line signal is available at the output of receiver coupler 11, the modem output signal has changed, so that no meaningful error signal can be produced and the necessary correction signal cannot be obtained and combined with the modem output signal in adder 5. This problem is overcome by modifying the circuit configuration of FIG. 1 with the implementation shown in FIG. 2, wherein delay circuitry is introduced into the path between the output of modem 1 and subtractor 13.
Basically, the configuration of FIG. 2 is identical to that of FIG. 1, except for the addition of a separate delay and memory address network. Specifically, to account for the above-described delays, the output of modem 1 is connected to a delay circuit 20. The output of delay circuit 20 is, in turn, connected to an input of subtractor 13, to be subtracted from the telephone line sample output of A-D converter 12. To effect the proper read-out and write-in addressing of memory 16, the delayed modem output is also applied to a differentiator 22 and to a quantizer 23 which may be identical to quantizer 18 and which generates an appropriate memory address digital signal based upon the characteristics of the delayed modem signal of interest. Connected between the outputs of quantizers 18 and 23 and the input and output of memory 16 is a gate circuit 24. Gate circuit 24 is formed of appropriate combinational logic to alternately apply the address outputs of quantizers 18 and 23 to memory 16. Gate circuit 24 also selectively connects the output of memory 16 to either adder 5 or adder 15. Namely, during correction of the modem signal, gate circuit 24 couples the read-out address output of quantizer 18 to memory 16, and couples the contents of this address as a correction signal to adder 5. However, the output of memory 16 is not coupled to adder 15 at this time. Subsequently, the delayed modem signal is converted into an updated correction address signal by quantizer 23, which address is coupled to memory 16, while the output of quantizer 18 is blocked. The contents of the presently addressed location in memory 16 are now coupled by gate circuit 24 to adder 15 to be combined with the error modification signal output of scaler 14 and rewritten back into memory. The path from memory 16 to adder 5 is concurrently blocked by gate 24, during the updating of the memory correction signal.
The output of delay circuit 20 is also coupled to one input of a subtractor 21. Another input of subtractor 21 is obtained from the output of A-D converter 12. Subtractor 21 generates an error signal which is fed back to delay 20 so that an adaptive delay of the modem signal correction process can be effected in response to time variant changes in the system. The details of the adaptive delay 20 are shown in FIG. 3, described below.
Referring to FIG. 3, the output of modem 1 is connected to the serial input of a multistage shift register 30, which functions as a tapped delay line. Selected stages of register 30 are connected to appropriate tap logic circuits, such as circuits 31, 32, and 33. Each tap logic circuit performs a functional operation on the contents of a stage of register 30 and subtractor 21 and the result is summed in adder 39 together with the results of the other tap logic circuits to create a delayed representation of the modem signals.
To this end, looking at the details of tap logic circuit 33, for example, selected contents of shift register 30 are multiplied in multiplier 38 by a stored tap weight value stored in weight value register circuit 37. The output from multiplier 38 is added in adder 39 to the outputs of tap logic circuits 31 and 32. To establish the desired weight value, selected contents of register 30 are multiplied in multiplier 34 by the error output signal from subtractor 21. The output of multiplier 34 is then scaled in a constant multiplier circuit 35 and added to the weight value stored in weight register 37 by adder 36. The modified weight value is then stored in register 37 as an updated weight value.
The action carried out by the adaptive delay circuit 20, shown in FIG. 3, effectively correlates the error signal from subtractor 21 with delayed versions of the modem output signal, with the delay feedback loop forcing the correlation result to zero for each increment value of delay. For a fixed delay, the correlation result will be high at only a single tap and the weight value for this tap will be increased to generate the necessary delay of the modem signal. If, in addition to delay, the coupler circuitry effects a filtering action on the signal, there will be correlation values at several adjacent taps of register 30, causing several tap weights to be adjusted to create a replica of the signal in its delayed and filtered form. This action of the adaptive delay is particularly useful where there is both delay and filtering imparted by the coupling elements.
The operation of the circuit configuration shown in FIG. 2 proceeds in substantially the same manner as described above in connection with FIG. 1, except that, due to the delay imparted to the modem signal by delay 20, a gating circuit 24 is activated to alternately connect the output of quantizer 18 to memory 16 in order to read out the contents of a selected memory address for supplying a non-delayed correction signal to adder 5, and then subsequently storing, in memory 16, a new correction signal for the delayed sample of the modem output in accordance with address signal generated by quantizer 23. Namely, the memory is accessed twice for each sample interval - once to obtain the correction signal to be added in adder 5 with the output of modem 1; secondly, to update a previously used correction signal.
Considering now the sequence of operations which take place for each successive signal sample, it will be assumed that on the basis of previous sampled values memory 16 has stored correction signals. Now, during one complete sample interval, quantizer 18 initially generates a first or read-out correction address for obtaining a correction signal to be added to the output of modem 1. Gate circuit 24 supplies this address to memory 16 and couples the read-out contents of this address as a correction signal to adder 5 to be combined with the output of modem 1. This combining effect compensates for the non-linearity imparted by coupler 3 to that particular type of signal, the characteristics of which cause quantizer 18 to define the address of the presently read-out contents of memory 16, the contents of which have been prepared and updated on the basis of previous data samples.
Subsequently, after the period of delay imparted by delay 20, quantizer 23 generates a second or up-date address. Gate circuit 24 couples this address to memory 16 and blocks the path from quantizer 18 to memory 16 and the path from the output of memory 16 to adder 5. The delay imparted by delay circuit 20 has adapted itself to the transmission characteristics from modem 1 through the system couplers so that the signal sample error supplied by subtractor 13, adjusted by scaler 14, is combined in adder 15 with the contents of the location in memory 16, defined by the second or up-date address from quantizer 16. Gate circuit 24 couples the output of this memory location to adder 15 so that a new or updated correction value can be generated and written back into memory. The contents of the location of this second or update address in memory 16 now contain the most recent correction value for correcting a signal sample from modem 1 having characteristics which would cause quantizer 18 to generate, as a read-out correction address, this second or update address. Gate circuit 24 now switches back to its previous state wherein an address generated by quantizer 18 may be coupled to memory 16 while the path from quantizer 23 is blocked. Also, gate 24 couples the output of memory 16 to adder 5 while it blocks the path to adder 15. In this condition, the system now proceeds to process the next data sample in the newly starting sample interval.
In place of the above delay imparted to the modem signal, the delay circuit can be inserted at the output of quantizer 23 to generate the necessary memory address signal for storage of the modified correction signal.
As will be appreciated from the foregoing description, the present invention provides an effective technique of interfacing high data rate modems with telephone line communication networks, without suffering from the typical non-linearities introduced by the coupling circuitry in the interface.
While I have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are obvious to one of ordinary skill in the art.
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Non-linearities imparted by an acoustic coupling instrument for interfacing data signals from a modem to a telephone line are compensated. Both the output of the modem and that of the non-linearity introducing instrument are monitored. The two output signals therefrom are compared and an error signal representative of the degree of non-linearity of the line signal is generated, and this error signal is then appropriately scaled and stored in a memory as a correction signal. Stored correction signals are read out of the memory in response to address signals defined by the characteristics of the signals from the modem, and are added to the modem output signals before they are imparted to the non-linear coupling instrument. The added correction signals effectively compensate for the non-linearity of the acoustic coupler, thereby removing the unwanted distortion from the telephone line signal. The contents of the memory are dynamically adjusted so that the system effectively adapts itself to the non-linearity of the instrument.
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BACKGROUND OF THE INVENTION
In one aspect, this invention relates to an improved shell and tube heat exchanger. In another aspect, the invention relates to apparatus and methods for reducing the pressure drop in the flow of shell side fluid in a shell and tube heat exchanger.
Heat transfer is an important part of any process. As is well known, an indirect transfer of heat from one medium to another is usually accomplished by the use of heat exchangers, of which there are many types. For example, there are double pipe, shell and tube, plate heat exchangers and others. Indeed, the art of heat exchanger design is developed to a very high degree; however, there is still room for improvement in a number of areas, such as reducing pressure drop, increasing overall heat transfer coefficients, reducing fouling and in heat exchangers utilizing a tube bundle, such as the shell and tube heat exchangers, in improving the flow of the medium through the shell in contact with the tube bundle. In shell-and-tube heat exchanger designs, it is frequently advantageous to utilize "vapor belts" or annular distributors to reduce shellside inlet and exit pressure losses, reduce impingement velocities, and improve shellside fluid distribution. In Standards of Tubular Exchanger Manufacturers Association, 6th Edition, 1978, the following shell side impingement protection requirements are set forth in Section 5, page 29:
"An impingement plate, or other means to protect the tube bundle against impinging fluids, shall be provided when entrance line values of ρν 2 exceed the following: non-corrosive, nonabrasive, single-phase fluids 1500; all other liquids, including a liquid at its boiling point, 500. For all other gases and vapors, including all nominally saturated vapors, and for liquid vapor mixtures, impingement protection is required. ν is the linear velocity of the fluid in feet per second and ρ is its density in pounds per cubic foot. A properly designed diffuser may be used to reduce line velocities at shell entrance."
An annular distributor is conventionally designed such that the ratios of nozzle-to-annulus flow area and annulus-to-slot flow area provide a recovery of static pressure by virtue of reduced momentum with passage through the nozzle, annulus, and shell slots. The exact magnitudes of these area ratios required to fulfil this criterion are not precisely predictable. If these area ratios are incorrectly specified by the designer, the pressure recovery through the annular distributor may be less than optimal and possibly result in a negative pressure recovery (i.e., positive pressure loss). It is thus desirable to provide apparatus and methods for adjusting such flow areas in tube and shell heat exchangers fitted with annular distributors, so that pressure drop can be minimized, particularly in the areas between nozzles and the shell interior, and flow through the shell and over the tube bundle optimized.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a shell suitable for use in a shell and tube heat exchanger, utilizing at least one shell side annular distributor, characterized by low shell side pressure drop, especially in the regions between the nozzles and the shell interior. It is a further object of this invention to provide means for adjusting the nozzle and shell slot or port flow areas, so that the flow area ratios of nozzle to annulus and annulus to shell ports can be optimized and pressure drop across the shell unit can be minimized. Another object of this invention is to provide means for adjusting the circumferential and radial distribution of fluid passing from an annular distributor into such a shell so that, e.g., a tube sheet installed within the shell would receive uniform distribution of the fluid entering the shell, such that the heat transfer process is optimized. A still further object of this invention is to provide a complete shell-and-tube heat exchanger with means for adjusting the nozzle and shell port flow areas, and/or adjusting the radial distribution of fluid entering the shell, so that the flow area ratios of nozzle to annulus and annulus to shell ports can be optimized (and thus pressure drop across the shell unit minimized) and the heat transfer process optimized.
These and other objects, advantages, details, features and embodiments of this invention will become apparent to those skilled in the art from the following description of the invention, the drawing, and the appended claims.
According to the present invention, a shell suitable for use in a shell-and-tube heat exchanger is provided, having an inner surface and at least one annular distributor attached to said shell, with at least one nozzle means in communication with the annulus of said annular distributor, at least one shell port which provides communication for said annulus with said inner surface of said shell, and means for adjusting the fluid flow area of at least one nozzle and/or at least one shell port.
Further according to the present invention, in a shell and tube heat exchanger comprising a tube bundle enclosed within a shell having a first end and a second end, wherein the shell is provided with a first nozzle near the first end for the introduction of shell side fluid and a second nozzle near the second end for the withdrawal of shell side fluid and annular distributors for said first nozzle and said second nozzle, a third nozzle for the introduction of tube side fluid and a fourth nozzle for the withdrawal of tube side fluid, the improvement is provided comprising means for adjusting the shell side nozzle and shell ports flow areas, so that the flow area ratios of nozzle to annulus and annulus to shell ports can be optimized and pressure drop across the annular distributors of the shell side can be minimized. According to another aspect of the invention, by employing variable area nozzle liners and adjustable area shell inserts, the annular distributor pressure recovery can be adjusted after fabrication of the heat exchanger to achieve design goals of minimum pressure drop across the shell side. In still another aspect of this invention, the optimal annulus-to-nozzle flow area ratio can be achieved by using nozzle liners of varied wall thicknesses, which alter the nozzle flow area. In a still further aspect of this invention, the shell ports-to-annulus flow area ratio can be varied to achieve optimal performance by using variable-width shell inserts, which are fitted into recesses machined on the inside or outside diameter of the shell and thus at least partially block the shell port flow areas.
Still further, according to yet another aspect of this invention, a method is provided for reducing pressure drop across the shell side of a tube and shell heat exchanger fitted with annular distributors for the shell side inlet and outlet nozzles which comprises using the nozzle liners provided above and/or the variable-width shell inserts provided above to obtain the optimal flow area ratios of annulus-to-nozzle and shell ports-to-annulus.
In yet another aspect of this invention, a method is provided for controlling the circumferential and radial distribution of fluid passing from an inlet annular distributor into a heat exchanger shell by rotably and/or slidably adjusting a variable-width shell insert such that the shell port flow areas exposed are smallest near the nozzle and largest on the opposite side of the shell. The radial distribution of fluid entering the shell through the ports can thus be essentially uniform, providing optimum heat transfer with a tube bundle when installed in the shell.
This invention is applicable to shells suitable for use in shell and tube heat exchangers having only one annular distributor, and to exchangers having annular distributors at both inlet and exit ends. In the latter case, basic design criteria can require that the inlet and outlet annular distributors be of approximately equal size, or of different sizes. For example, where the heat exchanger serves as a condenser as well, the inlet annular distributor will generally be larger than the outlet annular distributor.
Although the invention is illustrated in the drawings using a "one-pass" shell, the invention can be applied to other shells of various shell-tube heat exchangers. (See Chemical Engineers' Handbook, Perry and Chilton, 5th Edition, McGraw Hill Book Company, New York, copyright 1973, pages 11-3 through 11-17.) Such other shell types include a two pass shell with divider plate, split flow, double split flow, and divided flow. Provided that annular distributors of appropriate size are provided according to normal design criteria, this invention for "fine-tuning" the flow area ratios for optimal performance is applicable to all heat exchangers with at least one annular distributor.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an elevational view of a shell and tube heat exchanger with annular distributors fitted, which is taken in cross section and illustrates certain features of the present invention.
FIG. 2 is an elevational view of the nozzle affixed to the annular distributor of the heat exchanger shell shown in FIG. 1.
FIG. 3 is a cutaway view of the annular distributor and a portion of the shell of the shell and tube heat exchanger shown in FIG. 1.
FIG. 4 is a front view of the variable width shell insert shown in FIGS. 1 and 3.
FIG. 5 is an elevational view of the variable width shell insert of this invention shown in FIGS. 1, 3 and 4, in flat form, before being bent into cylindrical form for insertion into the shell of the heat exchanger.
FIG. 6 is a view of the variable width shell insert of this invention as inserted into the shell of the heat exchanger shown in FIGS. 1 and 3.
FIG. 7 is a cutaway isometric view of the annular distributor and shell shown in FIGS. 1 and 3.
FIG. 7a is an enlargement of a cross section of a portion of the apparatus shown in FIG. 7, illustrating the recess in the shell and the shell insert in the recess.
FIG. 7b is a cutaway isometric view similar to FIG. 7 showing the shell insert fitted in a recess on the outer surface of the shell rather than the inner surface.
FIG. 8 is a cutaway isometric view of a portion of the annular distributor and shell shown in FIGS. 1, 3 and 7, illustrating a modified variable width shell insert.
FIG. 9 is an elevation view of a pattern for cutting two of the modified shell inserts, as shown in FIG. 8, from a rectangular piece of sheet metal.
FIG. 10 illustrates apparatus used for measuring differential pressures in the shell and tube heat exchanger of FIG. 1.
FIG. 11 shows plots of the resistance coefficient K versus Reynolds Number to illustrate the present invention.
FIG. 12 shows plots of the resistance coefficient K versus Reynolds Number to illustrate the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Shell and tube heat exchangers fitted with annular distributors are preferably designed to minimize pressure drop across the shell side. The total pressure drop can be conveniently divided into the pressure drops in the inlet and outlet annular distributors, respectively, and the pressure drop inside the shell. A certain amount of pressure drop across the tube bundle is required to achieve the desired heat transfer, but conventional plate-baffle heat exchangers exhibit a relatively high pressure drop relative to the amount of heat transferred.
Improved heat exchangers, licensed by Phillips Petroleum Company as RODBaffle® exchangers, have been developed; see, e.g., U.S. Pat. No. 3,708,142, Jan. 2, 1973. Such heat exchangers have a relatively high rate of heat transfer compared with pressure drop. In applications, such as RODBaffle® exchangers, where there is relatively little pressure drop inside the shell, e.g., where the pressure drop inside the shell is approximately equal to the sum of the pressure drops in the inlet and outlet annular distributors, it is important to minimize the pressure drop through the annular distributors. That is, assuming that some maximum amount of pressure drop is allotted to a heat exchanger in a given installation, it is generally preferred to minimize the proportion of the pressure drop which takes place in the annular distributors so that a maximum proportion of the overall pressure drop can contribute productively to the heat transfer process inside the shell. When a heat exchanger is designed to maximize the ratio of heat transferred to total pressure drop, as with the RODBaffle® designs, this is particularly desirable. Thus while the present invention is applicable for shells of shell and tube heat exchangers generally, it is particularly applicable to shells of RODBaffle® heat exchangers.
For conventional liquid-to-liquid flows, it has been discovered that heat exchangers are preferably designed and constructed with annular distributors at both inlet and outlet sides of the shell and with the fluid flow area progressively "opening up" as the fluid passes through, at least in the inlet and outlet annular distributors. That is, the ratios of shell inlet flow areas mentioned earlier are greater than 1.0, such that the inlet annulus flow area exceeds the inlet nozzle flow area, and the inlet shell port flow area exceeds the corresponding annulus flow area. Furthermore, the outlet shell port flow area should generally be greater than the shell inlet port flow area, with the shell outlet annulus flow area larger than the shell outlet port area, and the outlet nozzle area larger than the outlet annulus area, so that the outlet flow area ratios of ports to annulus and annulus to nozzle are less than 1.0. To achieve the design criterion described above, it may be necessary to connect the inlet and/or outlet nozzles of a heat exchanger with inlet/outlet lines slightly larger or smaller (e.g., within 20%) than the nozzles. Alternatively, if economic or technical factors require that the nozzles and/or lines be of the same size, the criterion can be applied to the annular distributors separately, with, e.g., the shell ports for the outlet being smaller than those for the inlet.
However, many exceptions to this design criterion exist, particularly where a single annular distributor is employed, or where annular distributors of different sizes are required to accommodate vapor as well as liquid flow. In such cases, it is still preferred that the flow areas increase as a fluid passes through the inlet or outlet end systems of nozzle/annulus/shell ports, except where a vapor is condensed into a liquid.
According to this invention, means comprising nozzle liners and shell inserts are provided for adjusting the flow areas of nozzles and shell ports in the annular distributors of such shells, thus facilitating the optimization of the relevant flow area ratios and minimizing shell side pressure drop, particularly the pressure drops in these annular distributors. Heat exchangers can thus be "fine-tuned" for minimum shell side pressure drop upon installation, or when subsequently opened for overhaul, repair or inspection. Generally, removal of the tube bundle will be required for such fine-tuning. If sufficient capacity for adjustment is provided according to this invention, the flow of shell side fluid through such a heat exchanger could even be reversed without adversely affecting efficiency of operation, as illustrated in Example III. In an embodiment, the shell port inserts of this invention can be adjusted in an inlet annular distributor to control the circumferential and radial distribution of fluid passing from said distributor through the shell ports, thus, e.g., providing an essentially uniform distribution of fluid throughout the shell.
The following detailed description is directed to an embodiment of the invention as shown in the drawings, with emphasis on the inlet side of the heat exchanger. The same features and criteria generally apply to the outlet side of a heat exchanger, particularly to the type which preferably has an outlet annular distributor similar to the inlet annular distributor. Although the embodiment described has the inlet and outlet, with their respective annular distributors, at opposite ends of the heat exchanger shell, the invention is of course applicable to other designs, e.g., multiple-pass heat exchangers having the inlet and outlet at the same end of the shell, or even designs with multiple inlets and/or outlets for the shell. However, due to direction of flow, the ratios to be optimized are not identical. For an inlet annular distributor the ratios considered are annulus-to-nozzle and shell ports-to-annulus, while with an outlet annular distributor the ratios considered are annulus-to-shell ports and nozzle-to-annulus.
FIG. 1 depicts a shell-tube heat exchanger 10 comprising shell 12 and tube-bundle 14. The tubes 14 are affixed to tube sheets 13 which are held by flanges 44 bolted at 15. Shell-side fluid enters exchanger 10 via inlet nozzle 16 and shell side fluid exits exchanger 10 via outlet nozzle 18. To avoid excessive pressure drop, the inlet nozzle should generally be at least as large as the pipe entering it, and the outlet nozzle should be approximately the same size as the pipe it feeds to. Tube-side fluid enters the tubes via inlet conduit 20 and tube-side fluid exits the tubes via outlet conduit 22 for countercurrent flow. Liner 24 can be mounted within nozzle 16 to decrease the cross-sectional flow area of the shell side fluid charged into exchanger 10. Shell fluid annulus 26 is formed by inner cylindrical means 28, which can be an extension of shell means 12, and outer cylindrical means 30, the annulus 26 being a flow port for shell inlet fluid. Outer cylindrical means 30 form the annular distributor earlier referred to, which distributes fluid from the nozzle to the shell interior. Inner cylindrical means 28 has four shell ports 32 therein allowing the passage therethrough of fluid from annulus 26 into the shell side of exchanger 10, wherein indirect heat exchange of the fluid in the shell with fluid in the tubes of tube bundle 14 is effected. Materials of construction for such shells and tube bundles can, in general, be chosen from those available in commerce, taking into account the corrosive nature of materials entering the shell and tubes as well as the expected pressures of operation. The inner periphery of inner cylindrical means 28 has a recess 34, to retain slideably and/or rotably positioned cylindrical shell insert 36, preferably having four openings 38 therein, so that the four ports 32 can be at least partially closed. The cylindrical inserts are preferably installed in recess 34 in such a way that they can be adjusted by rotation as well as sliding. The four openings 38 therein are designed to facilitate the adjustment of the port flow areas for both pressure loss and axial flow distribution enhancement of fluid near the tube sheet. Said openings can be on one or more edge of such inserts, and/or in the central portion of the inserts, and can be of various shapes, comprising rectangular, rounded, triangular and the like.
FIG. 2 details the nozzle 16 with liner 24 therein. Shoulder 40 of liner 24 fits against receiving recessed means 42 of nozzle 16. Liner 24 can be provided with various wall thicknesses, to provide any nozzle flow area desired which is less than the original nozzle area. Nozzle liner 16 and shell insert 36 (FIG. 1) are preferably made of metals similar to those which they contact in the heat exchanger, thus avoiding the adverse electrolytic effects of adjacent dissimilar metals and being compatible with the fluids passing through the shell side. However, nozzle liner 16 can be made of other compositions of matter compatible with the shell-side fluid and resistant to friction, comprising plastics, ceramics and glasses. The nozzle flow area NA is defined as simply the cross-sectional area of the nozzle inside diameter, which can be altered by the use of the nozzle liners of this invention.
FIG. 3 is a detailed showing of inlet nozzle 16, liner 24, annulus 26, inner cylindrical means 28, outer cylindrical means 30, shell ports 32 in inner cylindrical means 28, recess 34, insert 36, and openings 38 in insert 36. Numeral 44 indicates the flange attached to the shell to which (not shown) the tube sheet 13 of tube bundle 14 can be affixed. Tube sheet 13 can be attached to flange 44 by, e.g., bolts 15.
As fluid passes from the nozzle to the annulus, it can proceed in two directions into the annulus. Thus, the efective annulus flow area AA, the area through which fluid flows, is twice the longitudinal cross-sectional area of the annular port. Expressed as a formula,
AA=2hl,
where AA is the effective annulus area, h is the radial height of the annular port, i.e., the distance between the annular wall and the shell and l is the length of the annulus along the longitudinal surface of the heat exchanger shell, as seen best in FIG. 3.
FIG. 4 is a cross-sectional view of insert 36 having the openings 38 therein.
Cylindrical insert 36 is preferably installed in a recess 34 in the inner surface of the shell, the inner cylinder 28. For this embodiment, it is desirable that the insert metal be tempered, worked or heat treated so that it is springy, allowing said insert to be installed so that it is held in position at least partially by expansive tension. The insert is preferably also fastened in place after adjustment by any appropriate mechanical means, comprising set screws, pins, shim rings, welding and the like. Cylindrical inserts can also be cut to fit snugly in the recess provided in the shell, with the openings in the inserts exposing the desired areas of the shell ports. The inserts are thus more simply and securely installed, but cannot be further adjusted by sliding longitudinally.
Cylindrical insert means can alternately be installed in a recess 34' cut into the outer surface of the shell (inner cylinder 28), as shown in FIG. 7b, in which case the metal of said insert means is preferably malleable rather than springy, and the inserts are preferably fastened securely in place after adjustment. This embodiment offers the advantage that the insert means can be made accessible through the open nozzle means if necessary for simplified adjustment.
Again referring to FIG. 3, it will be seen that in installing insert 36 in recess 34, the shell ports 32 will be covered to a greater or lesser degree, depending upon where said insert 36 is positioned by sliding and/or rotation. The effective shell ports flow area PA, defined as the total ports area uncovered or exposed, can thus be limited to any figure less than the total area of the ports before the insert is fastened in place.
Although for minimum annular pressure drop heat exchangers are designed so that the flow path areas progressively increase along the annular flow paths, by using combinations of the nozzle liners and shell inserts of this invention in at least the outlet side, it is possible to adjust a heat exchanger such as the embodiment depicted here for reversed flow through the shell side, as illustrated in calculated Example III. This can be advantageous in certain instances, e.g. where a heat exchanger can be physically installed more easily in one position than in another or where it becomes necessary to redirect the flow of shell-side fluid through a heat exchanger permanently installed in an existing system.
FIG. 5 shows insert 36 prior to being formed into a cylindrical configuration. In this figure the insert is flat, illustrating how insert means 36 can be cut from materials such as a sheet of metal.
FIG. 6 is a view of the closed cylindrical insert 36 with openings 38 and extension means 50. Ends 52 and 54 form the closure of ends of insert 36.
By preferably providing openings 38 in insert 36, the effective area of shell ports 32 can be closely adjusted by sliding and/or rotating the insert within recess 34. The openings can be in various shapes, placed on the edge or in the interior of the insert, designed to provide appropriate adjustments of the effective port flow area as the insert is slid or rotated. Such inserts can also be provided without such openings, i.e., as a strip of uniform or varied width, and will be operable to control the effective port flow area by sliding, especially if a relatively longer recess is provided.
FIG. 7 is a cutaway view of the invention showing, in greater detail, portions of the apparatus including annulus 26, inner cylindrical means 28, outer cylindrical means 30, ports 32 in means 28, recess 34 in the inner periphery of means 28, insert 36, openings 38 in insert 36, and extension means 50.
FIG. 7a is a detail of FIG. 7 showing a portion of inner cylindrical means 28 with the recess means 34 which is retaining insert 36, and has sufficient longitudinal space for movement longitudinally of insert means 36.
FIG. 7b is a cutaway view of an embodiment of the invention in which the shell insert is fitted into a recess on the outer surface of the shell, i.e., within the annulus. Shell inserts fitted in this manner would normally be installed before the annular distributor is attached, and could not be replaced as easily as inserts fitted inside the shell, but offer the advantage that means can be provided for adjusting the insert slideably or rotably by access through the open nozzle, without the necessity of removing the tube bundle.
FIG. 8 is a cutaway isometric view of another embodiment of insert means 36 which is numbered 36'. Insert means 36' is movably retained in recess 34 of the inner cylindrical means 28, which means 28 has ports 32 therein. Insert 36' is a truncated hollow cylinder, as illustrated, with the truncated end facing the adjacent tube sheet (not shown). Insert 36' is movable both longitudinally and rotationally in recess 34, so that proper adjustment of shell fluid flow can be attained. Preferably, the truncated end is positioned to allow more shell fluid flow to the tube locus remote from the shell fluid inlet nozzle, allowing that portion of the tubes opposite the shell fluid inlet and adjacent to the tube sheet to receive proper contact with the shell fluid for optimum heat exchange. The truncated end angle with respect to the longitudinal axis is between about 20 and about 70 degrees, normally about 40 degrees. The truncated end can be formed by cutting a cylindrical insert blank or by laying out a pattern on a sheet of material, and cutting this, and then forming the truncated cylinder for insertion into recess 34 as insert means 36'.
FIG. 9 illustrates a flat plate of material with marking thereon for cutting to produce the sheet to be formed into the cylinder with the truncated end for use as insert means 36'. In the drawing one rectangular blank sheet can be used to produce two cut sheets to form two inserts 36'. The illustrated cut, as laid out by descriptive geometry, produces a cylindrical insert which appears to be cut by a plane passed through the cylinder. It is pointed out that a curved cut can be used on the truncated end of insert means 36'. That is, for simplicity of flow specifications, the markings on the sheet can be straight lines rather than the curved line illustrated.
Insert 36' can be adjusted not only to give the desired area ratios of the annulus flow area to port flow area, but also to radially direct the shell fluid flow as desired for proper contact of shell fluid with the tubes remote from the shell fluid inlet nozzle.
The insert 36' can similarly be used at the outlet end of the shell-tube heat exchanger, to ensure that all tubes at that end receive full contact with the fluid before the fluid passes from the shell into the annulus.
FIG. 10 shows a test heat exchanger with pressure taps for determining various pressure differentials between the various pressure taps.
The following examples illustrate further details and embodiments of this invention but are not intended to unduly limit the scope thereof.
EXAMPLE I
To test for the effects of the relationships of the nozzle cross-sectional area, the annulus area, and the shell entry area on pressure drops across portions of the shell-tube heat exchanger, the following listed pressure points shown in FIG. 10 were used:
81. Within inlet nozzle;
82. Within inlet annulus at 45 degrees circumferentially from inlet nozzle;
83. Shell side of exchanger at inlet end at about 90 degrees circumferentially from inlet nozzle;
84. Within the inlet annulus at 135 degrees circumferentially from inlet nozzle;
85. Shell side of exchanger at about 180 degrees circumferentially from inlet nozzle;
86. Shell side of exchanger at about 90 degrees circumferentially from inlet nozzle;
87. Shell side of exchanger downstream from inlet annulus at about 90 degrees circumferentially from inlet nozzle;
88. Shell side of exchanger upstream from outlet annulus at about 90 degrees circumferentially from outlet nozzle;
89. Shell side of exchanger at about 90 degrees circumferentially from outlet nozzle;
90. Shell side of exchanger at about 180 degrees circumferentially from outlet nozzle.
91. Within the outlet annulus at 135 degrees circumferentially from outlet nozzle;
92. Shell side of exchanger at about 90 degrees circumferentially from outlet nozzle;
93. Within outlet annulus at 45 degrees circumferentially from outlet nozzle; and
94. Within outlet nozzle.
Various tests were made using different constant shell fluid flows, constant tube fluid flows, constant shell fluid inlet pressure and temperature, constant tube fluid inlet pressure and temperature, but at various ratios of nozzle radial cross-sectional areas to effective annulus areas, and of effective annulus areas to shell-ports' flow areas. Pressures were measured at different points (see above) and differential pressures were determined (correcting for pressure drops caused by tube bundle in the measured loci) to determine the effects of ratio changes on heat exchange efficiency.
In one set of data, the shell fluid was water at about 50° F. No tube side fluid was used in this isothermal operation.
The inlet nozzle cross-sectional area (NA) was 0.1278 square feet; the annulus flow area (AA), as defined herein, was 0.1409 square feet, and the inlet shell ports flow area (PA) was 0.1622 square feet. The ratios, as reported, were:
NA/AA=0.907
AA/NA=1.10
PA/AA=1.15
Results are summarized in Table I, below.
TABLE I__________________________________________________________________________ ρVn.sup.2(3)Run Flow Rate.sup.(1) Vn.sup.(2) (lb/ft- Va.sup.(4) Vp.sup.(5)No. (lbs/hr) (ft/sec) sec.sup.2 (ft/sec) (ft/sec) NRe.sub.n.sup.(6) ΔP.sup.(7) K.sup.(8)__________________________________________________________________________1 94,144 3.281 672 2.976 2.585 94,209 0.120 1.662 127,300 4.442 1231 4.029 3.500 156,113 0.536 4.053 179,686 6.271 2454 5.688 4.941 227,754 1.342 5.084 145,600 5.083 1612 4.610 4.005 191,237 0.796 4.595 173,923 6.072 2301 5.507 4.784 228,761 1.232 4.986 219,840 7.674 3675 6.961 6.047 287,113 2.161 5.467 248,046 8.641 4659 7.838 6.809 233,935 2.772 5.528 248,124 8.643 4661 7.840 6.810 227,841 2.881 5.739 330,362 11.510 8267 10.440 9.069 315,287 5.221 5.8610 408,501 14.236 12646 12.912 11.217 411,818 7.994 5.87__________________________________________________________________________ .sup.(1) Flow rate is pounds of water per hour; .sup.(2) Vn is velocity of water in nozzle, feet per second; .sup.(3) ρVn.sup.2 is pounds/cu. ft times nozzle velocity squared; ρ is actual pounds per cubic foot of water density; .sup.(4) Va is velocity of water in annulus, feet per second; .sup.(5) Vp is velocity of water through inlet ports; ##STR1## where Dn is nozzle diameter in feet; μn is actual viscosity of water; ρ is defined above; and Vn is defined above. ##STR2## where M is ΔP (psi) caused by tube bundle of segment from taps 81 t 86, which can be either measured or estimated as a proportion of the ΔP for the total length of the tube bundle; and ##STR3##
A specimen calculation for run 1 follows:
94,144 lbs/hr÷3600=26.1511 lbs/sec
ρ≈62.4 lbs/gal (water)
26.1511 lbs/sec÷62.4 lbs/cu ft=0.4191 ft 3 /sec; NA=0.1278 ft 2
Vn=0.4191 ft 3 /sec÷0.1278 ft 2 =3.2792 ft/sec
Vn 2 =10.7538 ft 2 /sec 2
ρVn 2 =62.4 lbs/ft 3 ×10.7538 ft 2 /sec 2 =671 lbs/ft/sec 2
μ=0.00088 lbs/ft/sec (viscosity)
(πDn 2 )/4=0.1278 ft 2 ; Dn=0.4034 ft
NRe.sub.(n) (Nozzle Reynolds Number)=(ρn Dn Vn)/μn ##EQU1## Although ρ changes with temperature and pressure, it can be seen that K is a function of
ΔP/Vn 2 .
Referring again to my K value, or resistance coefficient, reference is had to "Flow of Fluids Through Valves, Fittings, and Pipes", Trane Technical Paper No. 410, 1957, pages 2-8 and A-26, with equation 2--2 as rearranged.
Equation 2--2 shows
h.sub.L =(KV.sup.2 /2gc) (in feet).
By multiplying both sides by ρ(lbs/ft 3 ), the dimensions become pressure, (lbs/ft 2 ):
h.sub.L ·ρ=ΔP=(Kv.sup.2 ρ/2gc) (lbs/ft.sup.2)
solving for K (dimensionless),
K=ΔP2gc/ρV.sup.2.
The resistance coefficient should thus be minimized to obtain the minimum pressure drop across, e.g., the annular distributor, at least to the extent permitted by other factors.
Using the same apparatus that was used for the data in Table I, but using cooling water flow in the tubes (inlet temperature about 100° F.) and using heated water flow in the shell (inlet temperature about 150° F.), the results of this operation are summarized in Table II, below.
TABLE II__________________________________________________________________________ ρVn.sup.2Run Flow Rate Vn (lb/ft- Va VpNo. (lbs/hr) (ft/sec) sec.sup.2 (ft/sec) (ft/sec) NRe.sub.n ΔP K__________________________________________________________________________11 92,407 3.283 673 2.978 2.587 274,437 0.140 1.9712 135,726 4.824 1452 4.376 3.801 406,724 0.670 4.3713 173,097 6.159 2367 5.586 4.852 528,025 1.224 4.914 213,815 3604 6.893 5.988 641,450 2.114 5.5515 244,121 8.661 4681 7.856 6.824 707,739 2.836 5.7216 340,896 12.092 9124 10.968 9.528 984,246 5.716 5.9217 418,830 14.867 13792 13.484 11.714 1,224,857 8.914 6.1118 249,887 8.880 4921 8.054 6.997 745,894 2.979 5.7319 337,543 11.997 8981 10.882 9.453 1,010,942 5.717 6.0220 416,065 14.790 13650 13.415 11.653 1,248,884 8.857 6.14__________________________________________________________________________
These data illustrate that as the flow velocity Vn and Reynolds Number NRe n are increased, the pressure differential and resistance coefficient K increase. However, for a given range of Reynolds Numbers (which is dependent upon flow velocities), it has been found that generally lower K values, and thus lower ΔP, will be obtained when the values of the flow area ratios AA/NA and PA/AA are at least 1.0 for an inlet annular distributor. Calculations and tests should be performed separately for the outlet annular distributor, particularly when fluid is flowing in the tubes, due to density and viscosity effects.
EXAMPLE II
Using the method of Example I, test runs and calculations were performed on the inlet annular distributor system to study the effects of independently varying the ratios of annulus flow area to nozzle cross-sectional area and shell ports flow area to annulus flow area. Data for runs with the flow area ratio AA/NA (annulus area/nozzle area) adjusted to three values are presented in Table III. For each run, the values of the resistance coefficient K are tabulated for various Reynolds numbers for the nozzle. The flow area ratio PA/AA was held constant at 1.033 for all runs.
TABLE III______________________________________CURVE A CURVE B CURVE CAA/NA = 1.017 AA/NA = 1.2 AA/NA = 1.3NRe.sub.n K NRe.sub.n K NRe.sub.n K______________________________________324,928 6.20 387,149 5.92 192,786 3.96349,873 6.62 305,208 5.75 282,783 4.89186,230 5.46 254,212 5.52 335,054 4.99386,219 6.57 750,844 5.86 365,077 5.06488,100 6.50 998,442 6.11 558,153 5.32650,865 6.77 1,286,157 6.34 510,039 5.42494,315 6.15 541,520 5.36 554,976 4.80609,708 6.64 645,492 5.64 705,597 5.15714,917 6.75 677.727 6.16 771,758 5.31942,000 6.66 1,093,548 5.421,184,163 6.91 1,317,485 5.60______________________________________
The data of Table III are plotted in FIG. 11 as curves A, B and C. For the ranges of Reynolds Numbers covering the test runs, a family of flat curves results, with the values of resistance coefficient K decreasing as the inlet area ratio AA/NA is increased.
Using the same methods and holding the flow area ratio AA/NA constant at 1.02, runs and calculations were performed for three values of the inlet flow area ratio PA/AA. The data are tabulated in Table IV below and plotted in FIG. 12 as curves D, E and F.
TABLE IV______________________________________CURVE D CURVE E CURVE FPA/AA = 1.033 PA/AA = 1.15 PA/AA = 1.263NRe.sub.n K NRe.sub.n K NRe.sub.n K______________________________________324,928 6.20 280,747 6.00 215,871 5.04349,873 6.62 204,204 5.41 266,416 5.42186,230 5.46 257,592 5.91 251,169 5.66386,219 6.57 170,075 5.42 404,200 4.59488,100 6.50 490,342 5.40 430,974 5.96650,865 6.77 616,559 5.84 481,227 4.69494,315 6.15 695,833 6.06 592,603 5.35609,708 6.64 986,521 6.43 1,164,650 6.07714,917 6.75 1,191,277 6.61 967,440 6.01942,000 6.66 727,946 5.711,184,163 6.91______________________________________
The curves of FIG. 12 illustrate that K decreases as the inlet ports-to-annulus area ratio PA/AA increases, as would be expected. However, the effect of increasing (PA/AA) appears to be less pronounced than increasing (AA/AN). Over the range of geometric conditions, i.e., (AA/NA) and (PA/AA), tested, no optimum or minimum K values were observed. In principle, the resistance coefficient K would continue to decrease as inlet flow area ratios (AA/NA) and (PA/AA) are increased. Thus the ideal or optimum configuration would be goverened by the cost of increasing the annular distributor geometry and the savings realized by lower pressure losses associated with reduced K values. Furthermore, if the areas of inlet nozzles or outlet ports were decreased excessively, frictional effects should predominate and negate the advantage of increasing the flow area ratios. Separate effects are presented in FIGS. 11 and 12, however it is expected that when both inlet flow area ratios (AA/NA) and (PA/AA) are increased simultaneously, the flow coefficient K would be reduced below the values obtained when only one variable is increased.
In practical applications, a shell can be fabricated with inlet ports cut to the maximum size practicable, consistent with the proposed size of the annular distributors, strength of materials, radial distribution of fluid flow, and the requirements for protection of the tube bundle from impingement at the inlet end. Once the size and flow area of the annular distributors are determined, the shell port inserts can be adjusted during fabrication and/or installation of the heat exchanger to produce an inlet flow area ratio PA/AA which is a maximum. Assuming the nozzle diameters have been designed to be comparable to those of the inlet and outlet lines, nozzle inserts can then be added, if necessary, to maximize the flow area ratio AA/NA. Based on the data presented in this Example, it is preferred, at least for the inlet, to maximize the ratio AA/NA rather than the ratio PA/AA, provided this can be done without constricting the nozzle excessively or creating too great a mismatch between the nozzles and inlet or outlet lines. For instance, the inlet nozzle should not be constricted by inserting liners too much smaller than about 80% of the flow area of the inlet line (i.e., not less than about 90% the diameter of the inlet line), and the outlet nozzle should not have a flow area greater than about 120% that of the outlet line. It is advantageous to accomplish final adjustments of the flow area ratios by inserting or removing nozzle liners, due to ease of access and the fact that a greater reduction in K values, thus pressure loss, is obtained by increasing the flow area ratio AA/NA than by increasing the ratio PA/AA.
While not wishing to be bound by any theory, it is believed that increasing the inlet flow are ratios AA/NA and/or PA/AA will continue to produce lower K values, but at a constant AA, NA must be decreased to produce an increase in AA/NA, and at too high a ratio, the nozzle velocity will become so high that frictional effects, turbulent flow, etc. begin to predominate and the assumptions implicit in the calculations herein may no longer apply. Similar effects are expected to apply for the flow area ratios of an outlet annular distributor, except that the corresponding ratios should be less than 1.0 to produce the desired effect of progressively "opening up" as fluid passes from inlet to outlet.
For practical operations, the ratio of inlet AA/NA will be in the range of from about 1.0 to about 3.0, preferably from about 1.1 to about 2.0; and more preferably from about 1.1 to about 1.5. In addition, at constant AA, inlet PA must be increased to produce an increase in inlet PA/AA, but PA is limited in size because too great a PA minimizes the desired distributing effect of the annulus itself. For practical operations, the ratio of inlet PA/AA will be in the range of about 1.0 to about 3; preferably about 1.1 to about 2; and more preferably about 1.1 to about 1.5.
Similarly, for an outlet annular distributor, the ratio of outlet AA/NA should be in the range of from about 0.3 to about 1.0, preferably from about 0.9 to about 0.5, and more preferably from about 0.9 to about 0.6. Likewise, the ratio of outlet PA/AA should be in the range of from about 0.3 to about 0.1, preferably from about 0.9 to about 0.5, and more preferably from about 0.9 to about 0.6. From reference to the drawings and formulas herein, it will be clear that, for fluid passin through the shell of the instant invention from inlet to outlet, the inlet flow area ratios AA/NA and PA/AA are preferably greater than 1.0, while the identical ratios AA/NA and PA/AA for the outlet must be less than 1.0, since the fluid passes from nozzle to ports at the inlet, then from ports to nozzle at the outlet. When arranged in the sequence encountered by the fluid as it transits the outlet annular distributor, the inverse flow area ratios AA/PA and NA/AA would be greater than 1.0.
EXAMPLE III
Calculated Example
As a practical example of a variable-area, annular distributor, without limiting the invention thereto, let us consider an application in which an annular distributor is required at both the inlet and exit ends of the shell and tube heat exchanger. For economic reasons, a minimal pressure loss is required for both annular distributors, which may require final field adjustment of the nozzle and shell slot areas after the exchanger is fabricated. (The shell ports take the form of rectangular slots in the shell. The nozzle area can be reduced by inserting nozzle liners as previously disclosed. The shell slot area, hereafter referred to as shell port area PA as previously disclosed, can be reduced by partially covering the slots with a shell insert, as previously disclosed.) Similarly, for economic reasons the same annular cylinder size and nozzle size are to be utilized for both inlet and exit distributors. Further, in this example process conditions dictate that the flow direction on the shell side of the annular distributor exchange may be periodically reversed, i.e., the inlet distributor becomes the exit distributor and vice versa. Under these periodically reversed-flow conditions, it is economically advantageous to adjust shell slot and nozzle dimensions in place, rather than disconnect process piping and physically move the exchanger such that the annular distributors are reversed. An annular distributor design for use at both inlet and exit ends which accomplishes the above objectives is illustrated as follows. With no nozzle liners or shell inserts, the basic annular distributor design provides an annulus-to-nozzle area ratio (AA/NA) of 0.83. Similarly, with no shell inserts present, a port-to-annulus area ratio (PA/AA) of 1.30 is produced.
These ratios can be changed by using nozzle liners of known flow area, and/or by positioning a shell insert to partially cover the ports, leaving uncovered the portions of the ports whose areas are calculated to produce the desired flow area. Where the shell ports take the form of rectangular slots as in this example, the positioning of the inserts to produce specific flow areas can be easily calculated. Such points can be determined and marked in fabrication or field installation for exchangers with various types of ports.
When the above described annular distributor is to be employed as the inlet distributor, where flow areas PA>AA>NA, a series of nozzle inserts producing area ratios (AA/NA) of 1.10, 1.15, and 1.20 are provided. The shell inserts can be positioned to produce slot-to-annulus area ratios (PA/AA) of 1.10, 1.15, and 1.20. Based on field operations, to achieve minimum pressure loss, it is envisioned that the optimum area ratios would be approximately AA/NA=1.15 and PA/AA=1.20. This inlet annular distributor configuration would require a relatively thickwalled nozzle insert and a relatively small shell insert width (i.e. portion of the slots which is covered) to achieve AA/NA=1.15 and PA/AA=1.20.
At the outlet annular distributor, where flow areas NA>AA>PA, the shell insert employed would be adjusted to cover more of the machined slot area, ultimately producing an area ratio of AA/PA=1.15. Since preferably NA>AA, the nozzle liner at the exit end would probably be omitted, producing an area ratio NA/AA=1.20. As with the inlet annular distributor, the precise shell insert setting and nozzle liner size would be established through field tests. At such time as the shell side flow is reversed, the liners and inserts employed in the original inlet distributor could be installed in the original exit distributor to achieve the desired increase in area with flow direction.
While this invention has been described in detail for the purpose of illustration, it is not to be construed as limited thereby, but is intended to cover all the changes and modifications within the spirit and scope thereof.
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A shell unit, for use in a shell and tube heat exchanger, includes a shell having shell ports whose flow areas are adjustable. The unit comprises an annular distributor having an annulus which surrounds the shell such that fluid may flow from the annulus into the shell ports, and a nozzle in fluid communication with the annulus for feeding shell fluid into the annulus. A means is provided in the shell unit for adjusting the fluid flow area of the ports. In one embodiment, the means for adjusting the flow area is an insert rotatably mounted within the shell which may be rotated to at least partially cover the ports a selected amount.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for visualizing the presence and/or distribution of a liquid on a microtiter plate, microscope slide, glass cover slip or other laboratory member.
2. Description of the Prior Art
Microtiter plates are typically multi-well devices used primarily in biochemical analyses, particularly assays using the so-called ELISA techniques. Each well in the plate may receive a sample of a serum or other liquid under test. Suitable additional reagents may be added to the wells, either individually or "en masse," using hand held or automatic pipesetting techniques. Thereafter, following appropriate incubation and washing stages, the results of the biochemical reaction produced by the introduction of the reagent into the well may be automatically or manually monitored.
It is also common practice in a laboratory setting to use a so-called cover slip, or very thin glass plate akin to a microscope slide, to carry a liquid medium or sample for reaction with, for example, fixed cells and for subsequent microscopial examination.
Presently difficulty attends the determination as to whether a particular well in a microtiter plate or portion of a glass slip has a liquid sample disposed thereon. Further, it is often important to have a visual estimate of the relative volume and uniformity of distribution of liquid on the slip.
Accordingly, in view of the foregoing, it is believed to be advantageous to provide an inexpensive, easy-to-use arrangement operable with a cover slip, microscope slide, microtiter plate or other laboratory member to provide an indication as to the presence, uniformity of distribution and, in some instances, relative volume of liquid in or on the same.
SUMMARY OF THE INVENTION
The present invention relates to an apparatus for providing a visual indication of the presence of a liquid sample on a laboratory member such as a microtiter plate, microscope slide, glass cover slip or appropriate other laboratory member. In addition, the apparatus is also adapted, in appropriate cases, to provide an indication of the relative volume and/or distribution of the liquid sample.
The apparatus comprises a substrate with a substantially planar surface thereon. The substrate carries a predetermined visual pattern thereon. The substrate is positionable by a suitable mounting device to lie substantially parallel to, and a predetermined adjustable distance from, a laboratory member to be observed. As a result of the juxtaposition of the substrate with respect to the laboratory member, light reflected from the pattern and passing through the member is refracted and focused by the presence of the liquid thereby to alter the visual perception of the pattern by an observer and thus provide a visually perceptible indication of the presence, relative volume and/or distribution of the liquid.
The invention may be used in one particular embodiment with a microtiter plate having a plurality of wells therein. In an alternative embodiment, the invention may be used to ascertain the presence and/or distribution of a liquid on the surface of a planar member such as microscope slide or glass cover slip.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood from the following detailed description thereof, taken in connection with the accompanying drawings which form a part of this application and in which:
FIG. 1 is a side elevation view of an apparatus embodying the present invention adapted to provide an indication of the presence of a liquid in wells of a microtiter plate;
FIG. 2 is an enlarged top view taken along view lines 2--2 in FIG. 1;
FIG. 3 is a side elevation view in section of an apparatus in accordance with the present invention adapted to provide an indication of the presence and/or uniformity of distribution of a liquid on the surface of a clear planar member, as a microscope slide or glass cover slip, as the same is housed in suitable vessel such as a Petri dish.
DETAILED DESCRIPTION OF THE INVENTION
Throughout the following detailed description similar reference numerals refer to similar elements in all figures of the drawings.
As noted earlier, laboratory technicians working with any assay involving so-called ELISA techniques or using slides and incubating the same in Petri dishes are often faced with the problem of ascertaining the completeness of the dispensation of liquid into or onto the surface of the member being used. In some circumstances the technician is faced with the difficulty of ascertaining whether liquid is present in some or all of the wells in a multi-well member known as a microtiter plate. In other circumstances the technician is presented with the problem of ascertaining the presence and/or uniformity of distribution of liquid on the surface of a member such as a microscope slide or cover slip when the same is in repose in a Petri dish or other laboratory vessel. The present invention provides a simple, inexpensive and easy-to-use apparatus for ascertaining the presence and/or uniformity of distribution of a liquid on a member in these and other circumstances encountered by a technician in a laboratory setting.
Referring to FIG. 1, a laboratory member to be observed using an apparatus embodying the teachings of the present is shown in the form of a microtiter plate 10. The plate 10 is illustrated a shaving a substantially planar base 12 from which is supported a matrix-like array of wells 14. The plate 10 is typically fabricated from optically transparent material. The lower boundary of the individual wells 14 of the plate 10 may be either planar or curved.
A visualization apparatus 20 in accordance with the present invention is shown in FIG. 1 as comprising a generally planar substrate 22 having a predetermined optical pattern 24 supported thereon. The pattern is perhaps best seen in FIG. 2. The substrate 22 may be fabricated in any suitable manner, in any suitable configuration and from any suitable materials consistent with its function as a supporting base for the pattern 24. The apparatus 20 may itself be mounted or otherwise suitably supported on a surface S, such as a laboratory table (FIG. 1).
In the preferred instance, the substrate 22 is formed from an optically transparent material such as a clear plastic. The pattern 24 is embedded in the body of the substrate 22. The pattern 24 may be any visually perceptible arrangement of figures, motifs, designs, themes, images, whether in black and white or in color. In the preferred embodiment, the pattern 24 is in the form of a graphic arts pattern manufactured by Para-tone, Inc. Such patterns are available from Scientific Instrument Services, Inc., Ringols, New Jersey.
The substrate 22 is provided with mounting legs 26 at convention locations thereon. The legs 26 serve to support the microtiter plate 10 a predetermined clearance distance 28 above the plane of the pattern 24. In the embodiment shown in FIG. 1, the legs 26 are adjustable with respect to the plate 10 by means of screw threads which interact with similarly threaded openings provided in the substrate 22. Of course, any suitable mounting arrangement that serves to support the member being observed a predetermined optimum distance from the substrate 22 and from the pattern 24 lies within the contemplation of the present invention.
In operation, the member 10 to be observed is placed by an operator (diagrammatically indicated at 30) on the apparatus 20. The height of the legs 26 on the substrate 22 is adjusted until the predetermined optimum distance 28 is defined. Light reflected from the pattern 24 passes through the member 10 being observed. The presence of liquid on or in the member 10 being observed will refract and/or focus the reflected light and alter the visual perception of the pattern 24 to the observer. This is illustrated in the instance of the microtiter plate as schematically shown in FIG. 2. The alteration of the pattern 24 is perhaps best illustratable in this Figure as an alteration in the regularity in the size and spacing in the pattern 24. The refractive properties of the liquid in the well 14D has altered the visual perception of the pattern 24 disposed therebelow. The pattern 24 disposed beneath the wells 14A, 14B and 14C is shown as being visually unaltered. Different patterns would be visually altered in different fashions. For example, it lies within the contemplation of this invention to provide a pattern 24 which changes color due to the refractive properties of a liquid by causing spots of various primary colors to meld together to form a distinctive different color. Similarly, the refractive and/or focusing effect of the liquid will enable the use of a suitable grating pattern whereby the effect of the liquid would be to visually alter the pattern defined by the ruling on the grating.
Whatever the form of the pattern 24 used, the presence of liquid on or in the member 10 being observed changes the perception of the pattern 24 to an observer and thus provides a visually perceptible indication of the presence and/or the uniformity of the distribution of the liquid. In some instances it may also be possible to ascertain the approximate volume of the liquid present on or in the member 10.
The embodiment of the invention shown in FIG. 3 is adapted for use in providing a visual indication of the presence of liquid on a different type of laboratory member such as a planar transparent member in the form of a microscope slide or glass cover slip 36. The planar member 36 is housed within an optically clear vessel such as a Petri dish 40. The dish 40 may be supported on the legs 26 analogously to the plate 10 (FIG. 1). Alternatively, the dish 40 may be supported atop another Petri dish 41 having a pattern 24 therein. The height of the supporting dish 41 serves to support the member 36 being observed the predetermined distance 28 from the pattern 24. Suitable abutments 42, in the form of small O-rings, may be disposed on the bottom of the dish 40 to facilitate the manipulation of the planar member 36. Such abutments 36 are especially useful if the planar member 36 is in the form of a thin glass cover slip. As in the case of the microtiter plate light reflected from the pattern 24 passes through the bottom of the dish 40, through the planar member 36 and to the eye of the observer. A liquid on the surface of the planar member 36 alters the visual perception of the pattern 24 to the eye of the observer and thus provides an indication of the same.
Those skilled in the art, having the benefit of the teachings of the present invention, may impart numerous modifications thereto. For example, it is apparent that the apparatus in accordance with the present invention may be used with laboratory members other than those here discussed. In addition the pattern may be oriented in positions where the path of the light reflected from the pattern does not pass directly to the eye of the observer. As another alternative, it should be possible to project the pattern into and through the laboratory member. It should be understood, however, these and other modifications are to be construed as lying within the scope of the present invention as defined by the present claims.
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Apparatus for indicating the presence of a liquid on a member includes a substrate having a pattern thereon that is perceptibly visually modified by the presence of a liquid on the member.
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FIELD OF THE INVENTION
This invention relates generally to footwear and specifically to an improved system for making walking easier with boots of the type having substantially inflexible soles.
BACKGROUND OF THE INVENTION
Modern conventional ski-boots offer an example of footwear with relatively flat, non-bending soles. Other examples include foot covering made inflexible by plaster of Paris or otherwise braced for special medical or mechanical reasons, but this invention will be described in combination with ski-boots, the most common and widely used flat, rigidsole footwear.
Known in the art are the showings of the following U.S. Pat. Nos.:
1,938,617 to A. Augusta, Dec. 12, 1933, showed a strap-attachable member with heel and a sole that extends forward to the metatarsal area forming a pivotal support for walking without need to flex the shoe;
2,278,626 to J. R. Vasko, Apr. 7, 1942, showed a lace-up rounded bumper of rubber or the like that can be attached under a rigid cast on the foot to make it easier to walk;
2,423,354 to F. B. Van Hosen, July 1, 1947, showed a zipon boot with a "U"-shaped metal "walking iron" transversely supported under the instep;
2,519,613 to F. K. Urban, Aug. 22, 1950, showed a clampon device with a cylindrical lower surface transverse to the shoe making it easier and safer to walk with an injured foot;
2,526,205 to E. E. Doerschler, Oct. 17, 1950 (Re. U.S. Pat. No. 23,348) showed a rocker-shaped or arcuate ground-engaging surface attachable by wires to a cast; material suggested was rubber, plastic or wood pulp, for expendability.
Taken together these patents suggest that it is known to provide a system of flat topped detachable transversely extending member with length sloped to the front and rear forming a high central support for use under the rigid sole of a shoe or boot as a pivot for easier walking, and to make the member of resilient and/or disposable material.
SUMMARY OF THE INVENTION
However, such systems are not in widespread use, and a principal object of this invention is to provide a system as described that improves the general concept and makes such systems standard in the industry for the purposes noted.
Further objects are to provide a system as described with use-ready self-storing on boots when not in use and that offers two modes of use.
And further objects are to provide a system as described that teaches proper posture for skiing with knees slightly flexed, when the user stands with boot pivoted forward, boot toes touching the floor.
Still further objects are to provide such a system that has easy adjustment for locating walking pivot point as desired; fits a wide range of sizes of footwear, up to the largest made, that requires no modification of conventional modern ski-boots for use thereon, that is efficient, economical, easy to use, safe when used as intended, durable and reliable and attractive in appearance.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of this invention will become more readily apparent on examination of the following description, including the drawings in which like reference numerals refer to like parts.
FIG. 1a, 1b and 1c show a ski-boot with the preferred embodiment of the invention attached, in progressive stages of walking;
FIG. 2 is a front elevational view of the showing of FIG. 1b;
FIGS. 3 and 4 show respectively, elevational views of the left and right sides of a boot with the invention selfstored on the upper portion;
FIGS. 5 and 6 shows on an enlarged scale and in fragmentary, partly sectional elevational views, the relation in two positions of the boot when not in use storing the invention, as it may be used as a lever prying the bungee cord free of the recess around the heel of a boot;
FIG. 7 shows in elevational view another mode of use of the system with an ordinary ski-boot; the embodiment may, but need not be, different; the special surfaces shown can apply to the rocker in any Figure; and
FIG. 8 shows in perspective view and on an enlarged scale, details and relations of the parts of the preferred embodiment.
DETAILED DESCRIPTION
FIG. 1a shows the invention in preferred embodiment 10, a pivotal support system, installed on a ski-boot B of any conventional modern type. The wearer (not shown) is beginning a stride with rocker 20 on the floor F or other surface. Only the rounded apex 22 part of the rocker 20 touches the ground.
The rocker 20 is attached to the boot by a pair of loops; first and second loops 24, 26 of elastic, preferably bungee cord 28 that extend from the rocker 20 around the front or toe end of the boot and the rear or heel end of the boot in the conventional binding clamping grooves G', G" of the boot.
A hook 30 pivotally held on loop 26 at the heel end provides for storage of the system when removed from use on the sole of the boot as will be described.
FIG. 1b shows at the midpoint of a stride the function of the rocker in providing a pivot at the apex 22 of the rocker more normal walking motions than the conventionally stiff or inflexible boot sole S would otherwise permit.
FIG. 1c shows the stride-ending position, with rocker 20 pivoted forward of the apex 22 and the substantially normal leg and foot angle relative to the floor completing the substitution for the usual noisy Frankenstein-like clomping.
FIG. 2 shows in the front elevational view of the boot B with the system or embodiment 10 of the inventions attached, how the rocker 20 and apex 22 of it are preferably wider than the sole S of the boot and how the rocker preferably has flanges 32, 34 along the edges to hold the boot sole and restrain lateral movement relative to the boot sole. Except for the flanges the rocker is preferably uniform in height and in longitudinal cross-section. The bungee cord loop 24 extneds forwardly from holes in the rocker as will be indicated and similarly rearwardly for the rear loop. To provide additional lateral stability the bungee cord extends from the rocker in outwardly diverging directions, and is tightly stretched.
The shape of the boot protruding portions at toe and sole retains the bungee cords as well, as will be seen.
A problem with pivotal systems of the type is what to do with them when they are not in use. Carried in the hand, they can be laid aside, left behind or lost, and at least will be bulky to carry in pockets. What's needed is an almost foolproof storage.
FIG. 3 shows the solution to the transport and storage problem. When not in use, the system 10 is looped around an upper portion or shank, or top or leg portion of the boot B and fastened to itself with the hook on the far side or inner side for least bothersome protrusion of the system during walking/skiing. The hook and the use-ready transport and storage that it provides show in later figures. Preferably the apex 22 of the rocker 20 is turned outward and the flat top of the rocker inward, also for least protrusion. The means for storing includes both the provision of hook and of the loop structures's extension around the boot upper a distance requiring no adjustment beyond being correct for attachment to the sole.
FIG. 4 shows the hoop 30 detachably engaging the forward loop 24 of the bungee 28. The rectangular plan view of the rocker shows, apex out. The hook 30 open side (or free-end) is preferably oriented to the inside, against the boot, so that it will not snag the opposite boot during walking/skiing. Convenience and memory-jogging of the storage wil be appreciated. Also, as noted above, the length of the bungee does not have to be adjusted; the stretched length suitable for looping engagement of the boot sole front and rear is about the same as the stretched length required to stretch around and hold on the shank of the boot, for storage.
FIGS. 5 and 6 show successive positions of the hook 30; it has no function normally when the system is in use, during which it stores for safety at the rear of the sole S or a ski-boot in the clamping groove G". However, (FIG. 6, broken lines and arrow) the hook 30 can serve as a lever to pry the rear loop 26 of the bungee 28 free of the groove G" when removing the rocker from use-position under the boot sole.
FIG. 7 shows a further mode of use of the system, in a similar embodiment 10' with no modification required to it or to the boot. Permitting this is the generally longitudinal extension of the loops from the faces respectively of the inclined faces of the wedge shape.
In this mode the system is inverted, the flat face 38 of the rocker 20' is down and the apex 22 is up, supporting the boot B. (Loops 24, 26 are installed as usual). This places the pivot axis closer to the user's foot. Further, it leaves a greater-area "footprint", possibly advantageous in some uncertain footing such as mud, and since it provides for the ground-contacting portion of the rocker 20' to be stationary rather than in rotary, moving contact with the ground, may offer non-slip advantages on ice or other slippery footing. Moving contact between shoe-sole S and apex 22 may help prevent accumulation of debris. Provision of non-slip surfaces as by rubber covering and/or serrating, indicated at 40, is possible, and the flanged edges, 32 shown, may help guide somewhat like blades of an ice skate.
FIG. 8 shows in embodiment 10 the apex 22, the preferably concave (non-slip) inclined surface 42, 44 between apex and upper, flat portion 38, the flanges 32, 34 and the bungee securance in two sets of paired fore and aft generally horizontal holes 46, 48, 50, 52 that lead through the inclined faces or surfaces 42, 44 into a transverse, upwardly open recess 54 centrally in the upper flat portion.
To adjust the longitudinal position of the rocker relative to a boot sole, or the tightness, it is only necessary to adjust the length of either loop or both loops 24, 26 by putting the knots 28', 28" in the free ends of the bungee cord 28, at positions desired. Third knot 28"' prevents slippage. The bungee cord 28 may be in one piece as shown, with knot 28"' in the bight on one side, that centers the cord but can be shifted to suit.
The hook 30 may be any suitable conventional hook of sheet metal or otherwise thin, lightweight material. It will be appreciated that use of bungee cord provides a safer, less abrasive and lighter system than a heavy metal spring would, and that the hook may be of plastic or plastic-coated, accordingly.
The rocker may be of wood or plastic or other suitable material, disposable and cheap, as will be evident from the above.
This invention is not to be construed as limited to the particular forms disclosed herein, since these are to be regarded as illustrative rather than restrictive. It is, therefore, to be understood that the invention may be practiced within the scope of the claims otherwise than as specifically described.
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A quick-attach/detach footwear-sole rocker system provides for wearers of inflexible-sole footwear such as ski-boots to attach one to each boot sole and enjoy pivotal motion while walking. Each rocker has an elastic loop which may be of bungee cord extending forwardly and one extending rearwardly, for tightly looping around a boot toe portion and heel portion respectively. Adjustment may be by placing knots in the bungee cord at desired locations fixing the cord relative to hole structure in the rocker. Use-ready transport and storage of the rocker system when not in use is provided: a hook on one loop provides for stretching the rocker system around a boot-top or ankle portion and attaching the loops together.
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This is a continuation of U.S. patent application Ser. No. 08/439,160 filed May 11, 1995, now abandoned.
FIELD OF THE INVENTION
This invention relates to a device and method for storing cooked food portions at elevated temperatures and more particularly to a staging device for holding previously cooked food portions at elevated temperatures.
BACKGROUND OF THE INVENTION
Quick service restaurants face a number of conflicting factors when striving to provide fast, palatable and safe food. First, the customers expect to receive their food quickly, with a minimum of delay and with predictable and constant high quality. Moreover, the rate of customer demand varies over time, with some periods, such as lunch and dinner times, having extremely high rates of customer demand. However, the kitchens of many quick service restaurants are of limited size and/or production capacity and thus necessarily have a limited number of food cooking devices.
Typical food products that are of most interest include sandwiches that are composed of a bun or other bakery cooked bread product and a sandwich filling that is cooked at the quick service restaurant. Typical sandwich fillings include hamburger patties, breaded fish fillets, Canadian bacon, pork sausage, eggs and breaded chicken patties, for example, as well as other products, such as chicken nuggets, biscuits, muffins and hotcakes. Consequently, the cooked food supply capacity of the restaurant is limited by the size and number of food cooking devices located at the restaurant.
To meet the competing factors of quick service and consistent high quality, it is advantageous for quick service restaurants to frequently cook a number of individual food sandwich filling portions which are then almost immediately incorporated into individual sandwiches and then wrapped and held ready in advance of actual customer orders in an open storage bin for a relatively short predetermined period of time. To insure constant high quality, if the items are not sold prior to the expiration of that time, the sandwiches are destroyed. Holding the previously cooked, prepared and wrapped sandwiches incorporating the previously cooked sandwich fillings is thus of limited utility.
Since some quick service restaurants sell very large quantities of food, even a small increase in the efficiency of handling cooked sandwich fillings and other food would be desirable.
A need exists for a device and method that acts as a buffer between the relatively fixed and limited capacity of the sandwich filling cooking step and the highly variable completed sandwich demand without any significant adverse impact on sandwich quality or food safety. In addition, a need also exists for a food staging device which promotes efficient food handling and use of space within the kitchen of the quick service restaurant.
SUMMARY OF THE INVENTION
In accordance with the present invention, an improved food staging device and method for holding previously cooked food items at elevated temperatures is provided.
The device is particularly adapted for storing over extended periods of time cooked sandwich fillings such as hamburger patties, fish fillets, Canadian bacon, pork sausage, eggs, chicken patties, chicken fillets, as well as other types of food, including biscuits, muffins and hotcakes. When used in combination with trays specifically configured for use in the staging device, the appearance, taste, and texture of the previously cooked food items is maintained over extended storage periods (such as about up to two hours or more depending on the type of food) without risk of bacterial contamination.
In accordance with another aspect of the invention, a method is provided for storing previously cooked food, that is especially suited for a plurality of individual portion sandwich fillings, over extended periods of time without any significant detrimental effect on the quality of the food, including the appearance, taste and texture and without risk of bacterial contamination.
The food staging device in accordance with the invention includes a cabinet containing a plurality of discrete compartments, each bounded by an upper heated compartment surface and a lower heated compartment surface. The upper and lower compartment surfaces are constructed from a material having a high thermal conductivity, preferably from anodized aluminum. The previously cooked food portions are held within the compartments until the food portions are sold or otherwise disposed of. The air currents throughout the cabinet, if any, are limited because each of the compartments is segregated from other compartments and has solid upper and lower surfaces as well as closed sidewalls and limited access doors, the combination of which limits air flow in the compartments. In addition, air currents within the compartments are limited because both the lower and upper surfaces of the compartments are heated, thereby minimizing regions of thermal gradients within the compartments.
The device also includes at least one inlet door on one side of the device for inserting the food portions into the compartments and one complementary outlet door on the opposite side of the device for removing therethrough food portions contained in the compartments. This pass-through configuration of the doors promotes an efficient use of space in the kitchen containing the device because, for example, the device can be positioned intermediate the food cooking area and the cooked food assembly area, thereby providing cooking and assembly restaurant personnel separate access to the device. One inlet and corresponding outlet door may be provided to service one, two or more compartments.
In accordance with another aspect of the invention, the device may include a plurality of opposed corresponding inlet and outlet doors such that each of the compartments has its own inlet and outlet door. In addition, the inlet and outlet doors preferably are vertically spaced apart from each other by a distance approximately equal to the thickness of the doors to enable the doors to open by swinging in a generally upward direction, without any further structure enclosing the cabinet interior in the area between adjacent doors from the exterior. Thus, there is provided a relatively narrow, elongated slot opening permitting limited air flow between the compartment of the device and the atmosphere. Typically, the slot height should be no more than about 0.25 inches. Using a separate inlet and outlet door for each compartment further limits air transfer between the interior of the device and the atmosphere, thereby Limiting vapor transfer from the cooked food articles contained therein and further protecting the appearance, taste, and texture of the food portions. The inlet and outlet doors preferably are attached to the cabinet by pins located at the upper opposed edges of the doors, enabling the doors to open by swinging in a generally upward direction. If desired, no stops are provided for holding the doors open. Consequently, the doors automatically close by their own weight, thereby further minimizing air transfer and promoting a relatively constant temperature within the compartments. Alternatively, a stop may be provided for each door as desired to hold it in an open position.
In accordance with still another aspect of the invention, the device includes a plurality of trays for containing the food portions. One type of tray includes a sidewall having an upper edge and a lower edge, a closed bottom attached to the lower edge, and an open top defined by the upper edge. The trays have a height such that the top edges of the trays are a predetermined vertical distance, generally in the range of from 0 to 0.25 inches and most preferably about 0.16 inches, from the upper heated compartment surface when the trays are inserted into the compartments. The preferred gap for biscuits and hotcakes is about 0.125 inches. A typical tray height is in the range of from about one inch to about 2.5 inches. By limiting the space between the top edges of the trays and the upper compartment surface, evaporation of liquid from the cooked food portions is minimized, thereby maintaining the appearance, taste, and texture of the cooked food held in the device over extended storage periods such as up to about two hours. In addition, the trays can be configured such that the length of the trays is less than but approximately equal to the depth of the compartments thereby enabling easy removal of the trays through the outlet doors of the compartment.
Typical storage temperatures are in the range of from about 145°-200° F. and preferably about 160° F. for biscuits, about 170° F. for hamburger patties, grilled chicken, eggs, Canadian bacon, pork sausage, and muffins, about 200° F. for breaded chicken nuggets, breaded chicken fillets, breaded fish fillets and hotcakes. Trays with solid bottoms and raised sides are preferred for unbreaded meat and other food products such as hamburger patties, grilled chicken, eggs, Canadian bacon, pork sausage, biscuits and hotcakes. Flat trays with a mesh or wire grid with no sides are preferred for breaded products including breaded chicken nuggets, breaded chicken and fish fillets and also for muffins (preferably longitudinally cut in half and stored with the cut side up for both halves).
In accordance with yet another aspect of the invention, each of the compartments includes an upper electric resistance heating element for heating the upper compartment surface and a lower electric resistance heating element for heating the lower compartment surface. The temperatures generated by the heating elements therefore can be individually controlled by appropriate control circuitry. Consequently, the temperatures of the compartments can be separately controlled thus providing different holding temperatures in different compartments. As a result, the device can be used to simultaneously hold previously cooked food items at two or more temperatures, therefore eliminating the need for separate staging devices and further promoting an efficient use of space within the kitchen containing the staging device.
In accordance with another aspect of the invention, a method of storing previously cooked food products is provided. In accordance with this method, the previously cooked food products (such as individual portion sandwich fillings) are stored in a device that is composed of at least one compartment for holding the food portions, with the compartment bounded by upper and lower heated compartment surfaces. A cabinet defines an enclosed volume for housing the compartment therein, the cabinet including at least one door for inserting and removing the food portions from the compartment, where the compartment has a predetermined compartment height and width. The method includes placing the previously cooked sandwich fillings and at least one tray having a solid bottom and upwardly extending tray walls resulting in a tray height that is about 0 to 0.25 inches less than the compartment height. Thereafter, the tray containing the cooked sandwich fillings is placed in the heated compartment with the heated compartment surfaces having a temperature in the range of from about 145° F. to less than the boiling point of water. A gap is achieved between the top of the tray and the upper heated compartment surface between about 0 and 0.25 inches for restricting water vapor evaporating from the sandwich fillings contained in the tray. Thereafter, the inlet door is closed and the sandwich fillings in the tray are stored for a desired period of time.
Preferably, in accordance with the foregoing method, the cooked sandwich fillings stored in the tray fill at least about 5% and most preferably at least 17% of the tray volume.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cooked food staging device according to the invention;
FIG. 2 is a front elevational view of the device in FIG. 1;
FIG. 3 is a partially cut-away side elevational view of the device in FIG. 1 showing the placement of food-containing trays within the device;
FIG. 4 is a partially cut-away front elevational view of a second cooked-food staging device according to the invention;
FIG. 5 is a partially cut-away side elevational view of the device in FIG. 4;
FIG. 6 is an exploded view of two of the heated shelves within the device in FIG. 4;
FIG. 7 is a sectional view taken along line 7--7 in FIG. 5 showing the attachment of the shelves to the cabinet of the device in FIG. 4;
FIG. 8 is a partial perspective view of a portion of the food staging device of FIG. 1;
FIG. 9 is a perspective view of a tray for use in the device of FIG. 1;
FIG. 10 is a perspective view of an alternative tray used in the device;
FIG. 11 is a perspective view of a wire grid support used in the device;
FIG. 12 is a sectional view of the wire grid support of FIG. 11 taken along line 12--12 of FIG. 11 and having schematic food portions depicted thereon;
FIG. 13 is a partial elevational view of the interior of a cooked food staging device according to the invention and showing an alternative means for securing shelves within the device;
FIG. 14 is a perspective view of the interior of the device in FIG. 13; and
FIG. 15 is a sectional view of a portion of the interior of the device in FIG. 13 taken along line 15--15 of FIG. 14 and showing a shelf therein.
DETAILED DESCRIPTION
Referring to the Figures generally, where like reference numerals refer to like structure, and in particular to FIGS. 1-3, there is illustrated a cooked food staging device 20 according to the invention. Device 20 includes a cabinet 22 having two sidewalls 24 and 26, a closed top 28, and a closed bottom 30. As shown in FIG. 1, device 20 may be supported by a separate support structure 31. Alternatively, device 20 may rest directly on the floor (not shown) or on a table (not shown) via bottom 30. Front 27 of device 20 also includes vertically spaced apart inlet doors 32A-E and 34A-B, located on inlet side 1 of device 20, as illustrated in FIG. 3. Inlet doors 32A-E swing open upwardly and generally are all the same width and height. Inlet doors 34A-B, however, are larger than inlet doors 32A-E to provide access to larger holding compartments for larger cooked food items, such as biscuits 36, as shown in FIG. 3. Alternatively, all inlet doors can have the same dimensions. As shown in FIG. 3, device 20 also includes outlet doors 33A-E, located opposite inlet doors 32A-E, and outlet doors 35A--B, located opposite inlet doors 34A-B. For each inlet door 32A-E or 34A-B there is a corresponding outlet door 33A-E or 35A-B located on outlet side O of device 20 as illustrated in FIG. 3. Each of inlet doors 32A-E and 34A-B, as well as outlet doors 33A-E and 35A-B, are hinged to cabinet 22 along their upper edges and can include a reinforcing member 38 (shown in FIGS. 1-3 and 8) attached to their upper edges. Reinforcing members 38 generally are U-shaped channels extending along the length of each door 32-35, with the top portion of each door 32-35 being disposed in a force-fit relationship in the channel portion of its respective reinforcing member 38. Each of reinforcing members 38 has ends 39 that are closed as illustrated in FIGS. 2 and 8 and each has a pin 39' mounted thereto and extending parallel to the length of member 38. Each pin 39' is disposed in a corresponding aperture (not shown) in cabinet 22, to provide the hinging mechanism for doors 32-35.
Raising doors 32A-E, 33A-E, 34A-B and 35A-B provides access into the discrete, heated compartments 40A-E and 42A-B, respectively, contained within cabinet 22, as best seen in FIG. 3.
Doors 32A-E, 33A-E, 34A-B and 35A-B include handles 44 to facilitate opening doors 32A-E, 33A-E, 34A-B and 35A-B to gain access to compartments 40A-E and 42A-B. Doors 32A-E, 33A-E, 34A-B and 35A-B do not include any stop members which would retain them in an open position. Each of doors 32A-E, 33A-E, 34A-B and 35A-B thus moves to a closed position under its own weight when its respective handles 44 are released, thereby preventing sustained heat losses from compartments 40A-E and 42A-B. Each door is spaced apart from its adjacent door(s) by a predetermined distance approximately equal to and slightly greater than the thickness of the lower of the two doors. For example, as seen in FIG. 2, door 34B is spaced apart from adjacent door 34A by a distance 37 which is approximately equal to the thickness of door 34B. In a preferred embodiment, the door thickness is about 0.25 inches and distance 37 is slightly greater than about 0.25 inches. Cabinet 22 can also include a fixed upper front panel 46 located above top inlet door 32A and a fixed lower front panel 48 located below bottom inlet door 34B, as seen in FIGS. 1 and 2. Similar panels 46' and 48' are provided for the outlet side O of device 20. A control keyboard 50 and a display 52 located along panel 46 are operatively connected to the control circuitry of device 20 and enable programming and monitoring of the temperatures and times within each of the heated compartments 40A-E and 42A-B.
Preferably, control keyboard 50 controls a microprocessor controller (not shown) that is programmed in a known manner to provide the desired temperature control, time control and display information. Preferably, each of compartments 40A-E and 42A-B is programmable to a desired set point temperature within the specified temperature range for upper and lower heated surfaces 64 and 66, depending on product type.
If desired, a separate display can be provided for breakfast, lunch and dinner types of food. The display can be divided into a series of rows and columns, each row corresponding to one of compartments 40A-E and 42A-B. Each column corresponds to a horizontal tray position. For example, as shown in FIG. 2, there are five horizontal tray positions (trays 54A-E) and seven compartments resulting in a display having seven rows and five columns. Each column and row can be set to display the row and column number, the name of product stored in that position in device 20 and the countdown hold time remaining for that particular product. Preferably, the row and column display with the lowest time remaining for that product will be highlighted on the display so that the operator can select that tray first.
When a product type is selected for a particular row and column, the desired temperature set points are implemented for the corresponding upper and lower heated surfaces 64 and 66. The microprocessor controller checks the other columns (positions) in that row (shelf) for compatible temperatures considering food products already in storage on that shelf, and if not compatible, an audible beep can be generated, the input not accepted and "incompatible product selection" or other warning as desired displayed on display 52. For example, chicken nuggets (200° F. storage temperature) should not be stored on the same shelf with hamburger patties (170° F. storage temperature.)
FIG. 2 shows device 20 with inlet door 32B raised to provide access to trays 54A-E within compartment 40B. For ease of handling by a person, trays 54A-G preferably are constructed from a material having a low heat capacity, such as polycarbonate. Preferably, each of trays 54A-E, as well as trays 54F-G shown in FIG. 3, has a width 56 smaller than the width 58 of compartments 40A-E and 42A-B to permit placing more than one tray within a compartment. FIGS. 9 and 10 depict trays 54G and 54A, respectively. In the preferred embodiment shown in FIG. 2, width 56 is chosen relative to width 58 such that five trays 54A-E will fit within any of compartments 40A-E and 42A-B. In addition, each of the trays has a length almost equal to the depth 62 of compartments 40A-E and 42A-B, as seen in FIG. 3. For example, tray 54F is of length 60.
Each of compartments 40A-E and 42A-B is bounded by an upper heated compartment surface 64A-G and a lower heated compartment surface 66A-G, as shown in FIG. 3. Each of lower heated compartment surfaces 66A-G is flat and substantially horizontal to provide uniform heat transfer to trays 54A-G and permit easy sliding of those trays along the surface of lower heated compartment surfaces 66A-G. Each of trays 54A-F has a height 68 defined by the distance between the upper edge 70 of the sidewall 72 and the lower edge 74 of sidewall 72 of trays 54A-F. Height 68 is chosen so that upper edge 70 of any of trays 54A-F is at a predetermined distance 76 from upper compartment surfaces 64A-F when trays 54A-F are placed within compartments 40A-E so that vapor transfer out of the interior of the trays is minimized, thereby also minimizing the fluid loss of the cooked food portions stored therein which is important for cooked food stored in trays 54 such as egg products, hamburger patties, grilled chicken, pork sausage and Canadian bacon. Preferably for such food, the cooked food portions fill more than about 5% and more preferably about 17-30% or more of the volume of trays 54 when stored in device 20. Generally, minimal vapor transfer is achieved out of the interior of the trays when distance 76 is in the range of 0-0.25 inches. Most preferably, height 68 is chosen so that the distance 76 is approximately 0.16 inches (0.125 inches for biscuits). In the embodiment shown in FIGS. 1-3, compartments 42A-B are of greater height than compartments 40A-E to accommodate larger food portions such as biscuits 36. Consequently, when trays 54A-F are placed within compartments 42A-B, upper edges 70 are at a substantial distance greater than distance 76 from upper heated compartment surfaces 64F-G. Sidewall 73 of tray 54G has an increased height 69 so that a gap 77 is provided between the upper edge 70' of tray 54G and upper heated compartment surface 64G. Gap 77 is about 0.16 inches (0.125 inches for biscuits).
For cooked, breaded food such as breaded chicken nuggets, breaded fish and chicken fillets, achieving minimal vapor transfer is usually not desirable because such food may have a tendency to become soggy. Sogginess is usually objectionable for cooked, breaded food products. Consequently, a larger gap than distance 76 should be employed such as at least 1.0 inch, for example. Alternatively, cooked, breaded food products may be stored within one or more of compartments 40A-E or 42A-B on a wire grid support or on a tray having a wire grid support therein. FIGS. 11-12 illustrate a wire grid support 79 that is suitable for supporting cooked, breaded food products within compartments 40A-E and 42A-B.
Wire grid support 79 comprises a polycarbonate tray 81 that houses a removable frame 87. Frame 87 is connected to a grid having wires 83 and perpendicular wires 85 as shown in FIGS. 11 and 12. Cooked, breaded food products P are placed on wire grid support 79 in order to provide air circulation beneath breaded food products P so that they do not become soggy. Wires 83 and 85 have a diameter of about 0.06 inches, thereby providing a spacing from the surface of tray 81 of about 0.12 inches. It is advantageous to minimize the distance from the heated surface yet still provide an airspace from the heated lower compartment surfaces 66A-G.
Returning now to FIG. 3, upper heated compartment surfaces 64A-G and lower heated compartment surfaces 66A-G are constructed from a material having a high thermal conductivity and preferably are constructed from anodized aluminum.
The previously cooked food portions are held within compartments 40A-E and 42A-B, preferably within trays 54A-G, until sold or otherwise disposed of. Because compartments 40A-E and 42A-B are discrete, with well-defined upper heated compartment surfaces 64A-G and well-defined lower heated compartment surfaces 66A-G, air currents throughout cabinet 22, if any, are limited because surfaces 64A-G and 66A-G obstruct air flow within cabinet 22. In addition, air currents within compartments 40A-E and 42A-B, if any, are limited because both upper heated compartment surfaces 64A-G and lower heated compartment surfaces 66A-G are heated thereby reducing or eliminating thermal incongruities within compartments 40A-E and 42A-B. By restricting the air currents throughout cabinet 22 and within compartments 40A-E and 42A-B, device 20 reduces the amount of moisture lost from the food portions held therein and thus protects the appearance, taste, and texture of the food portions. Evaporation of liquid from the food portions is further minimized by choosing height 68 of trays 54A-F such that upper edges 70 of trays 54A-F are at a small, predetermined distance 76, generally preferably greater than 0 and less than about 0.25 inches and most preferably 0.16 inches, from upper compartment surfaces 64A-E when trays 54A-F are placed within compartments 40A-E for minimizing vapor loss from the food contained therein. For increasing the amount of vapor loss, gap 76 can be increased.
Device 20 also promotes an efficient use of space within a kitchen containing device 20. A kitchen in a quick service restaurant is frequently divided into two or more work areas. For example, the food cooking area can include food cooking devices such as grills, deep fat fryers, and other cooking devices, for example, for cooking sandwich fillings such as hamburger patties, fish fillets, chicken fillets, eggs and chicken nuggets. After being cooked, the food portions are transported to the sandwich assembly area for sandwich assembly which can include applying condiments to the cooked food portions, placing the cooked food portion in a roll or bun, and/or wrapping the cooked food portions. Consequently, restaurant personnel in the food cooking area and in the sandwich assembly area handle the cooked food portions. Device 20 promotes an efficient use of space when device 20 is located within the kitchen intermediate the food cooking area and the sandwich assembly area. When so positioned, the restaurant personnel responsible for cooking can place a tray 54E containing the cooked food portions within compartment 40A through inlet door 32A of device 20 inlet side I, as shown in FIG. 3. Then, when the cooked food portions are needed for assembly into a sandwich, restaurant personnel remove tray 54E from compartment 40A through outlet door 33A of outlet side O of device 20, as shown in FIG. 3. The flow-through configuration of inlet doors 32A-E and outlet doors 33A-E thus enables the cooking and assembly personnel to have completely separate access to cooked food portions held within device 20.
FIGS. 4 and 5 illustrate a second embodiment of a cooked-food staging device 80 according to the invention. Device 80 includes a cabinet 82 having two sidewalls 84, 86, a closed top 88, a closed bottom 90, an upper front panel 92, a lower front panel 94, and a right front panel 96. Keyboards 114 and displays 116 are provided in right front panel 96 to program and monitor the temperatures within the holding chambers 100A-F contained within cabinet 82. Holding chambers 100A-F are bounded by upper heated chamber surfaces 102 and lower heated chamber surfaces 104. Chambers 100A-F are also bounded by inlet doors 108A-F and outlet doors 112A-F hingedly attached along their upper surfaces to cabinet 82 in a manner as described previously with respect to device 20. Doors 108A-F and 112A-F are lifted by grasping handles 118 to thereby gain access to chambers 100A-F. In FIG. 4, inlet doors 108A and 108B are raised to reveal trays 120 contained within chambers 100A and 100B. The width 122 of trays 120 is such that three trays 120 will fit within any of chambers 100A-F. The length of trays 120 is almost equal to the depth of chambers 100A-F so that trays 120 may be readily handled through inlet doors 108A-F and through outlet doors 112A-F, as best seen in FIG. 5. Cabinet 82 can also include a compartment 98 for holding non-heated food portions. Compartment 98 is bounded by an inlet door 106 and an outlet door 110, both of which provide access to compartment 98. Doors 106 and 110 include handles 118 for rotating doors 106 and 110 along their upper hinged edges.
FIGS. 6 and 7 illustrate one system for attaching upper heated chamber surfaces 102 and lower heated chamber surfaces 104 to cabinet 82. Surfaces 102 and 104 are parts of shelves 126 and 128 which contain heating components for heating surfaces 102 and 104. Preferably, the source of heat is an electric resistance heating element, the construction of which is well known in the art. In addition to surface 102, shelf 126 includes a hollow housing 130 overlying surface 102. The heating component is positioned within the space between housing 130 and surface 102. Similarly, shelf 128 includes surface 104, an underlying housing 132, and a heating component positioned inside housing 132. Surfaces 102 and 104 are attached to housings 130 and 132 by conventional methods, such as rivets 134. Surfaces 102 and 104 extend beyond housings 130 and 132 to form flanges 136 and 138 which contain holes 140 and 142 for attaching shelves 126 and 128 to cabinet 82. Surfaces 102 and 104 are separated by two spacers 144, each of which includes posts 148 for engaging the holes of the overlying flange, for example, holes 140 of flange 136. Clips 150 underlying shelf 128 include posts 152 for engaging holes 142 of flange 138. Clips 150 also include prongs 154 for engaging shelf brackets 156 attached to sidewalls 84 and 86.
As best seen in FIG. 7, shelf 128, including lower heated chamber surface 104, is attached to clip 150 by inserting post 152 through hole 142 of flange 138. Clip 150 in turn is attached to bracket 156 via prongs 154. Spacer 144 is then positioned over shelf 128 and clip 150 so that post 152 is inserted into an opening in the bottom of spacer 144. Finally, shelf 126 is aligned with and mounted on spacer 144 so that post 148 extends through hole 140 in flange 136. The height 158 of trays 120 is chosen so that the top edges 160 of trays 120 are at a predetermined distance from upper heated chamber surfaces 102, as previously described with respect to device 20, when trays 120 are placed within chambers 100A-F. However, since the height of chambers 100A-F is determined by the height of spacers 144, different chamber dimensions can be achieved by using differently sized spacers. Consequently, device 80 can be readily configured to provide holding chambers which can accommodate trays having various heights.
An alternative embodiment device is depicted in FIGS. 13-15 as staging device 180. Staging device 180 has an exterior sidewall 182 and an interior sidewall 183 attached thereto, as most clearly seen in FIG. 14 by any suitable structure, such as by a weld or fastener, for example. Angle irons 184A-G are mounted to interior side wall 183 to support shelves 186A-G. Each end of angle irons 184A-G uses an upturned tab 184' for preventing lateral movement of shelves 186A-G when mounted thereon. Shelves 186A-G define heated compartments 188A-H.
FIG. 15 is an enlarged view of shelf 186C, which is representative of the other shelves. Shelf 186C includes an upper heated surface 190, a lower heated surface 192 and a housing 194 for storing the heating components (not shown).
In use, device 80 can be positioned within the kitchen of a quick service restaurant in an area intermediate the food cooking area and the food finishing area. The flow-through design of inlet doors 106 and 108A-F and outlet doors 110 and 112A-F thus promotes an efficient use of space within the kitchen. Device 80 also protects the appearance, taste, and texture of cooked food potions held therein because the discrete upper and lower heated chamber surfaces 102 and 104 limit air currents within device 80, thereby reducing or eliminating moisture losses from the food portions. In addition, electrical resistive heating elements can be used as the heating components for heating surfaces 102 and 104. Such heating elements can be individually controlled by the control circuitry of device 80. As a result, device 80 can be used to simultaneously hold previously cooked food portions at two or more temperatures, therefore eliminating the need for separate staging devices and further promoting an efficient use of space within the kitchen containing device 80. Generally, the heated chamber surfaces will be maintained in the temperature range from about 145° F. to less than the boiling point of water during the period of time that the sandwich fillings are stored in the chambers.
Whereas the present invention has been described with respect to specific embodiments thereof, it will be understood that various changes and modifications will be suggested to one skilled in the art and it is intended that the invention encompass such changes and modifications as fall within the scope of the appended claims.
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A cooked food staging device and method is provided. The cooked food staging device allows previously cooked food items, particularly sandwich fillings such as hamburger patties, fish fillets, biscuits, Canadian bacon, pork sausage, eggs, chicken patties, chicken fillets and nuggets, to be stored over extended periods of time at an elevated temperature without significant deleterious effects to the appearance, taste and texture of the food while avoiding risk of bacterial contamination. The food staging device is composed of a plurality of discrete compartments bounded by upper and lower heated compartment surfaces. Food can be stored within the compartments in trays having side walls of a height such that a gap is achieved between the top of the tray and the upper compartment heated surface to limit and control the evaporation of liquid from the food stored therein.
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This is a continuation of application Ser. No. 715,461 filed Mar. 25, 1985, now abandoned, 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 a composition and method of use for the treatment of mucocutaneous lesions by the topical administration of an effective amount of a composition comprising diphenhydramine, lidocaine, aloe, propolis and sufficient base to obtain a pH of 8-9.
2. Description of the Prior Art
Various agents have been used to treat oral lesions within the oral cavity. Among the most widely used are gentian violet, methylene blue, hydrogen peroxide and surfactants, such as ceepyrn (Cepacol). However, these agents have met with limited success and their clinical efficacy leaves much to be desired.
Antihistamines have been commonly employed in dental practice however, mostly for the allergic reactions involving the oral tissues and structures. Among the most widely used antihistamines are ChlorTrimeton, Benadryl, Pyribenzamine and Phenergan. The use of antihistamines has met with very limited success in controlling edema, facial swelling or trismus, etc. resulting from oral surgical procedures.
Corticosteroids have been used in dentistry but only to a limited extent. The most widely used corticosteroid for interoral use is Kenolog (triamcinolone acetonide) which is marketed in an adhesive base (Orabase). The use of this preparation is quite limited since its use is contraindicated in the presence of fungal, viral or bacterial infections of the mouth or throat.
Local anesthetics for topical use are available for dental practice. Tetracaine and dibucaine produce the most adequate topical anesthesia. However, the most widely used is Xylocaine Viscous (lidocaine) available as a 2% aqueous solution adjusted to a pH of 6.0-7.0. It is indicated for use of inflamed and denuded mucus membranes. Generally for an adult an amount of less than 1 ounce, usually 1/2 ounce, is administered at intervals of not less than 3 hours with no more than 8 doses being administered in a 24 hour period. The maximum single does for a healthy adult is 2 mg/lb body weight and does not in any case exceed a total of 300 mg. The peak effect on the mucus membrane appears in 2-5 minutes and the duration of the effect is 30-60 minutes.
When using oral topical anesthetics the patient is cautioned to avoid food and beverages for one hour after application since the production of topical anesthesia may impair swallowing and thus enhance the danger of aspiration. Numbness of the tongue or buccal mucousal may increase the danger of biting trauma.
Diphenhydramine HCl elixer is used topically as a 10 mg per 4 ml elixir or may be diluted with equal parts of water for its minor anesthetic effect for painful oral conditions such as pemphigus vulgaris, stomatitis, aphthosis and glossodynia. Diphenhydramine is also used topically as a cream (Surfadil) or a lotion (Ziradryl).
Havsteen discusses flavonoids their presence in bee propolis and their therapeutic applications such as pain relief and promotion of healing. B. Havsteen, Flavanoids, A Class of Natural Products of High Pharmacology Potency, Biochemical Pharmacology, Volume 32, No. 7, pp. 1141-1148, 1983.
Product literature for a tooth gel "Forever Bright" indicates the use of aloe vera as a inhibitor and a killer of bacteria which are known to cause plaque and bee propolis as having a natural antibiotic action.
U.S. Pat. No. 3,892,853 teaches the use of aloe vera gel by physicians and dentists in relieving pain and in promoting healing of topical and other lesions.
Also in the prior art is a mixture used to treat oral lesions comprising equal amounts of Benadryl, Amphojel and Xylocaine 2% solution, hereinafter Original Composition. The therapeutic dose is one teaspoonful (5 ml) and at low doses this composition does not interfere with swallowing.
The treatment of oral lesions by oral compositions has heretofore met with limited success. With some compositions, the anesthetic effect is coupled with a caution against eating or drinking for about an hour after applying because of the potential aspiration of swallowed material. With other compositions the anesthetic effect either takes too long to reach a therapeutic level or fails to numb the area altogether. For example, the treatment of canker sores which are characterized by ulcers which are confined to the oral mucosa in an otherwise healthy patient, with oral compositions has met with limited success. Present remedies such as spirits of camphor, alcohol 70%, salt water rinses, Blistex, cortizone-like drugs and topical adhering gels such as Orabase have been recommended.
For recurrent or the more troublesome causes of oral lesions such as recurrent herpes simplex or recurrent aphtheloris stomatitis (canker sores) no satisfactory topical treatment is available. The efficacy and safety of neutral red dye and photo therapy (photo inactivation), topical ether or alcohol has not been established. Idoxuridin is of questionable benefit.
A more troublesome oral lesion is secondary to cancer chemotherapy, for example methotrexate therapy. These are large, deep necrotizing ulcers which may effect all mucosal surfaces. Mouth rinses which include a local anesthetic, such as Dyclone, and an antihistamine, such as diphenhydramine, have been used for these lesions.
Zovirox topical ointment is indicated for the treatment of herpes genitalis. Topical application has shown a decrease in healing time and in some cases a decrease in the duration of viral shedding and duration of pain.
What is needed is a composition which will provide relatively longlasting relief of the symptoms associated with oral cavity lesions and promote the healing of the lesions. The composition of the invention allows for the patient to maintain adequate nutritional intake, by relieving symptoms associated with oral lesions.
It is an object of the present invention to provide a mucocutaneous composition that will provide immediate and relatively long-lasting relief from adverse symptoms such as itching, burning and pain caused by mucocutaneous lesions.
It is a further object of the present invention to provide a mucocutaneous composition that will promote healing.
It is a further object of the present invention to provide a mucocutaneous composition which is easy to administer.
It is a further object of the present invention to provide an oral composition that will promote the well being of the patient by diminishing the pain and discomfort of the oral lesion thereby allowing the patient to ingest food and beverages.
It is a further object of the present invention to provide an oral composition which produces a selective topical anesthetic effect at the lesion site(s) when the composition of the invention is applied orally, thereby allowing the ingestion of food and beverages shortly after administration.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims.
SUMMARY OF THE INVENTION
The present invention relates to a composition and method of use for the treatment of pain and inflammation associated with lesions, such as herpes simplex, herpes labialis, herpes progenitalis, chickenpox lesions, herpes genitalis, sensitivity of the gingiva tissue due to procedure for etching teeth with HCl, swollen gums, cheilosis, ulcers resulting from chemotherapy, oral traumatic injury (wound due to puncture from foreign object) and recurrent aphthous stomatitis by administering to the lesion an effective amount of a topical composition comprising diphenhydramine HCl, lidocaine HCl, aloe vera gel, propolis and sufficient base to attain a pH of 8-9. The composition may be applied locally by application with a cotton applicator or orally by swishing throughout the oral cavity, holding for two minutes and expectorating. For treatment of sore throat the patient swishes and gargles the composition throughout the oral cavity, holding for two minutes and then swallowing slowly.
The topical anesthetic onset of action of the composition of the invention is usually about one or two minutes after application with the duration of action usually about twenty to forty minutes.
Both the onset of action and the duration of action by the inventive composition are unexpected since the amount of lidocaine used is less per dose than taught by prior art compositions. Generally in an adult 15 ml (1 tablespoon) of Xylocaine 2% solution is used. This means about 0.3 gram of lidocaine is used per dose verses 0.025 grams per dose, one teaspoonful, of the inventive composition. It is further noted that in the original composition (equal amounts of diphenhydramine elixir, aluminum hydroxide gel and lidocaine viscous (2%)) contains 0.033 grams of lidocaine per dose. Following oral administration of the inventive or original composition the second stage of swallowing (the pharyngeal stage) does not appear to be interfered with thereby permitting the ingestion of food and beverages. This is unexpected since with the majority of oral topical anesthetics the patient is cautioned not to eat or drink within 60 minutes of administering an oral anesthetic throughout the oral cavity to prevent the possible aspiration of food. Surprisingly, the numbness produced by the composition of the invention appears to be selective i.e., mostly at the lesion site. This is based on the fact that a patient using the inventive composition experiences diminished adverse symptoms, but is still able to taste food and beverages.
Hence, inventive composition not only facilitates eating, but also provides short-term pain relief (numbness) which allows for the ingestion of oral therapeutic drugs such as maintenance drugs or antipyretic drugs, if needed.
The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other compositions for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
The composition of the instant invention promotes healing and relieves adverse symptoms such as burning and pain, associated with irritated--inflammed mucous membrane of the mouth and throat. The composition of the invention is composed of five elements:
diphenhydramine HCl about : 0.06% to 0.09% by weight
lidocaine HCl about: 0.5% to 0.7% by weight
aloe vera gel about: 20% to 35% by weight
propolis about: 1% to 2% by weight and sufficient base to raise the pH to 8-9, plus any necessary pharmaceutical excipients.
The frequency of the dose is at least 3 or 4 times per day and the dose quantity is one teaspoonful (5 ml.). The maximum dosage is about 2.4 grams (lidocaine HCl) per 24 hours in equally divided intervals.
The base is selected from the group consisting of aluminum hydroxide gel, magnesium hydroxide mixture such as Maalox. It is critical to the invention that the pH of the final solution be within a range of 8-9. That is, while any base which is pharmaceutically acceptable may be used in the invention to attain the desired pH, it is critical that the pH be in the range of 8-9. The aforementioned bases appear to prepare the most pharmaceutically elegant composition.
Aloe vera gel relieves pain and promotes healing of topical lesions. The stabilized form provides the longest shelf life and therapeutic efficacy without refrigeration. The aloe vera gel used in the inventive composition should be pure. Aloe vera gel is readily available as see U.S. Pat. No. 3,892,853. There are many aloe vera gel preparations available. For the inventive composition, the amount of aloe vera gel is based on the more pure forms, namely about 99-100% pure. Lidocaine HCl and diphenhydramine HCl may be added either as the aqueous solution (2% Xylocaine Viscous) or the elixir (Benadryl Elixir) respectively or as any form available to attain the required amount.
The therapeutic applications of bee propolis are reported to be the promotion of healing, relief of pain, antibiotic action, among others. These actions are based on the presence of flavonoids in the propolis.
The composition is a liquid for ease of administration throughout the oral cavity or mucous membrane.
Pharmaceutical preservatives, such as methylparaben and propylparaben, may be used. The only criteria in the selection of a preservative is that it would not be incompatible with the active ingredients. Flavorants, such as cinnamon, peppermint and spearmint may be used. Thickening agents such as sodium carboxymethylcellulose, carrogeen may also be used. Sweetening agents such as Nutra-Sweet, sugar, or sodium saccharin may also be used.
The selection of any or all of the above pharmaceutical excipients can be made by one skilled in the art of pharmaceutical preparations. Moreover, the active ingredients may also be delivered to the lesion site by way of a cream base. However, the pH of the resultant cream must be 8-9.
EXAMPLE
In order to prepare 120 ml (liquid) of the composition of the invention:
Amphojel (aluminum hydroxide gel): 30 ml
Benadryl (diphenhydramine HCl 10 mg/4 ml) elixir: 30 ml (75.0 mg)
2% Xylocaine viscous: 30 ml (0.6 gm)
Aloe (100% pure): 30 ml
Three, 500 mg propolis tablets: 1.5 grams (1.25% w/v)
Crush the tablets in a mortar and pestal, add other ingredients to attain a volume of 120 ml and mix well to insure proper dispersion of the ingredients. Flavorants, sweeteners and other pharmaceutical excipients may be added, however, the pH of the final product must be in the range of 8-9.
The composition of the invention is applied to mucocutaneous lesions at least 3 or 4 times per day. For application to the skin, a sufficient amount is applied to the lesion site which relieves the adverse symptoms. The maximum dosage is the amount of the inventive composition which contains about 2.4 grams lidocaine per 24 hours applied in equally divided intervals.
COMPARATIVE DATA
In order to compare the effect of the added aloe and propolis in relieving burning and pain and in the promotion of healing, three composition were prepared. Composition no. 1 (prior art) was composed of three equal amounts of Benadryl elixir, Xylocaine viscous 2% and Amphojel. Composition no. 2 (composition of the inventio) was composed of equal amounts of Benadryl elixir, Xylocaine viscous 2%, Amphojel, aloe vera gel and 1.5 grams of propolis per 120 ml of composition. Composition no. 3 (not prior art--comparative composition) was composed of equal amounts of Benadryl elixir, Xylocaine viscous 2%, Amphojel and aloe vera gel (100% pure).
Various lesions were treated:
(1) Aphthous ulcer
(2) Sensitivity of gingival tissue due to etching of teeth procedure using HCl etchant
(3) Traumatic injury (wound due to puncture from foreign object)
(4) Swollen gums
(5) Cheilosis (cracks in corner of mouth)
(6) Herpes simplex (canker sore, fever blister)
The mixtures were applied either locally to the lesion itself, that is, by way of a cotton applicator where the composition remained in contact with the lesion for two minutes or they were applied orally (entire oral cavity treated) to the lesion, that is, the mixture was taken into the mouth, swished around the oral cavity without gargling, held for two minutes and then expectorated. The entire oral cavity was treated unless noted otherwise. The patient tested in each group was about 14 years of age with the youngest and oldest for all groups being 8 years and 36 years respectively. The dose was one teaspoonful (5 ml) given 3 or 4 times per day.
Of those treating their oral lesions with composition no. 1, they respond as to the effectiveness:
very effective: 1
effective: 4
not effective: 1
The lesions treated were:
very effective: traumatic injury (1)*
effective: traumatic injury (2); aphthous ulcer (1); gingival sensitivity to etch compound (1)
non effective: cheilosis (1)
Of those treating their oral lesion with composition no. 2, they responded as to the effectiveness:
very effective: 8
effective: 8
not effective: none
The lesions treated were:
very effective: aphthous ulcer (1); gingival sensitivity due to etch compound (2); traumatic injury (2); swollen gums (1); herpes simplex (2) (one patient applied the composition to the lesion with a cotton applicator)
effective: aphthous ulcer (3) (one patient applied the composition to the lesion with a cotton applicator); traumatic injury (4); cheilosis (1)
Of those treating their oral lesion with composition no. 3, they responded as to the effectiveness:
very effective: 3
effective: none
not effective: none
The lesions treated were: aphthous ulcer (2); traumatic injury (1)
Days to heal:
It is noted that with or without the use of a topical agent, healing usually occurs itself, for example with canker sores within ten days.
Composition no. 1 took the longest time averaging 7.1 days.
Composition no. 2 averaged 4.8 days and composition no. 3 averaged 3 days; however, one patient stated that the composition did not heal at all.
All of the users of the composition no. 2 expressed that the composition "brought comfort". The majority of users of mixtures no. 1 and 3 expressed that it also brought comfort, however some noted that it only brought "some comfort".
The above data represents a surprising and unexpected result since the prior art teaches using stronger concentration of lidocaine to attain a similar therapeutic response. Not only is the effective dose lower, but the therapeutic response as measured by the comfort after use is better in the inventive composition.
A lower effective dose with the same frequency means less chance of toxic or adverse actions. Furthermore, the chance for the development of hypersensitivity due to repeated applications of lidocaine to the mucous membrane may be lessened.
The present disclosure includes that contained in the appended claims as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.
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A composition and method of use for the treatment of pain and inflammation associated with lesions of the skin or mucus membrane, such as herpes simplex, herpes labialis, herpes progenitalis, chickenpox lesions, herpes genitalis, sensitivity of gingival tissue due to procedures for etching teeth with HCl, swollen gums, cheilosis, oral traumatic injuries, aphthous ulcer, by applying to the lesion an effective amount of a topical composition comprising diphenhydramine HCl, lidocaine HCl, aloe vera gel, propolis and sufficient base to raise the pH to 8-9.
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This is a continuation of application Ser. No. 207,289, filed Nov. 17, 1980, now abandoned.
This application is related to divisional application Ser. No. 390,859 filed June 22, 1982, now allowed.
BACKGROUND OF THE INVENTION
This invention relates generally to microwave circuits and to the fabrication thereof.
The state of the art in fabrication and construction of millimeter and sub-millimeter wave length microwave systems before the present invention was essentially a "bolt together" waveguide component technology. Individual circuits or discrete components were developed and then interconnected to provide the desired system. In essence, the "blocks" of the overall block diagram of the microwave system were assembled after each "block" was individually developed.
Various problems and shortcomings are inherent in the "bolt-together" approach. One such shortcoming is the high frequency limitation that exists when separate components are bolted together. The size and separation of individual components cannot be scaled proportionally for extremely short wave lengths, resulting in uncontrollable parasitic reactances which limit performance. Other difficulties inherent in the waveguide approach are bulkiness, excessive weight, and high manufacturing costs. In addition, minor design changes can result in costly hardware modifications.
The technology of electronic circuitry has evolved from discrete components such as diodes, transistors, capacitors, and resistors on printed circuit boards to the use of monolithic linear and digital integrated circuits. This trend has continued by combining specific integrated circuit functions into larger integrated circuits having versatile and multi-function capability such as in the case of electronic calculators, watches, and micro-computers.
Concurrently with these developments in electronic circuitry, similar techniques have been employed in the technology of microwave circuits. GaAs field effect transistors (FETs) have been developed as well as microwave integrated circuit components such as oscillators, mixers, amplifiers, detectors, and filters, using both monolithic and hybrid construction techniques. With the development of the micro-strip radiator, high performance monolithic micro-strip phased arrays have also been developed.
It has been recognized that there are advantages in performance and versatility to be gained by building micro-computer controlled antenna systems. Various multi-mode systems have been developed to demonstrate these advantages. In such systems, the electronics, comprising integrated circuits mounted on printed circuit boards were packaged separately and interfaced with an antenna by means of a multi-conductor cable. Such construction represents the present state of the art in microwave system fabrication. To date, complete microwave systems have not been fabricated as a monolithic unit.
SUMMARY OF THE INVENTION
Realizing the inherent disadvantages and shortcomings of the previously utilized "bolt together" technology for the fabrication of millimeter and sub-millimeter wave length microwave systems, it is the primary objective of the present invention to provide a non-optical microwave system incorporating all of the system components including active and/or passive RF components such as amplifiers, FET phase shifter switches, phase shifting and other r.f. transmission circuits, a microprocessor controller, and related digital control circuits into a single monolithic semi-insulating GaAs substrate to provide a monolithic phased array antenna system for use at X-band frequencies and above.
A further objective of the present invention is to provide a fabrication process for monolithic microwave integrated antennas suitable for high volume, low cost production that is also repeatable and reliable.
The monolithic microwave integrated antenna system and the method of fabrication described herein enable the physical integration of active microwave and digital circuits onto a common semi-insulating GaAs substrate. The fabrication technique provided by this invention is not unique to a particular microwave system design but rather is applicable to a wide range of systems and system frequencies, i.e., 10 GHz through 10 8 GHz (ultraviolet). The fabrication technique set forth herein is based upon thin-film techniques. The fabrication of all components whether active or passive and their interconnections are formed by either semiconductor or thin-film processing steps.
Using the fabrication technique set forth herein, design changes can be implemented through mask and/or material and process variations rather than through the previously required intricate hardware modifications.
The monolithic nature of the microwave system has the inherent benefits of low volume (non-bulky), light weight, and high reliability. The fabrication process lends itself to automated, high volume production so that even the most complex designs will be repeatable and cost effective when compared with present fabrication and assembly techniques. The inherent accuracy and precision of the process enables PG,8 component size and separation to be scaled with frequency thereby eliminating or reducing parasitic reactances for improved performance. The inherent repeatability will eliminate the need for "tweaking" or circuit adjustment to meet performance specifications.
In essence, the systems and fabrication techniques set forth herein represent a unique marriage of the arts of semiconductor and integrated circuit fabrication techniques, used at frequencies lower than microwave, with integrated monolithic electromagnetic system techniques.
The invention recognizes and builds upon the commonality of materials and processes associated with digital and linear integrated circuits, active and passive microwave semiconductor devices, microwave integrated circuits and monolithic antenna systems. The present invention also recognizes that it is both technically advantageous and unique to integrate these devices into a functional monolithic system.
The fabrication technique features the use of ion implantation directly into high quality semi-insulating GaAs to form the active layer for planar FET elements.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in further detail with reference to the accompanying drawings wherein:
FIG. 1 is a block diagram of a monolithic microwave integrated circuit receiver according to the present invention;
FIG. 2 is a block diagram of a monolithic microwave integrated circuit transmitter according to the present invention;
FIG. 3 is a schematic diagram of a monolithic microwave integrated circuit adapted to receive visible light and deliver dc power;
FIG. 4 is a graphical representation of the E-plane half power beamwidth of a sapphire element radiator, plotted from experimental results;
FIG. 5 is a cut-away side view of a microstrip radiator element showing a 90° E-plane half power beamwidth;
FIG. 6 is a cut-away side view of a microstrip radiator element showing a 126° E-plane half power bandwidth;
FIG. 7 illustrates the physical structure of a single gate FET switch used in the phase shifter elements;
FIG. 8 is a schematic diagram of the equivalent circuit of the single gate FET switch shown in FIG. 7;
FIG. 9 is a schematic diagram of the preferred embodiment of one of the 4-bit phase shifters utilizing a hybrid design;
FIG. 10 is a physical schematic of a branch line hybrid coupler;
FIG. 11 is a backward wave quadrature hybrid coupler;
FIG. 12 is a schematic diagram of a loaded line phase shifter; and
FIG. 13 depicts the fabrication process for the planar GaAs FET phase shifter elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, there is shown a block diagram of a first embodiment of the monolithic microwave integrated circuit according to the present invention. The embodiment shown in FIG. 1 is a four (4)- element microcomputer controlled phased array. The phased array shown in FIG. 1 is configured as a receiving array. The corresponding transmitting array is shown in a second embodiment in FIG. 2. Continuing to refer to FIG. 1, all components are integrated onto a common semi-insulating GaAs substrate 30. The phased array is controlled by a microcomputer 32 operating in accordance with a program stored within a read only memory (ROM) 34. The program stored in ROM 34 defines the beam pattern to be followed by the phased array. A random access memory (RAM) 36 provides volatile memory for microcomputer calculations during the execution of its program. For a desired scanning pattern, microcomputer 32, based upon the program of ROM 34 computes the phase setting appropriate for each of four (4) phase shifter elements 38, 40, 42 and 44. These phase shifter elements control the phase shift of the four (4) array elements 46, 48, 50, and 52, respectively.
As previously stated, FIG. 1 is a receiver configuration. Signals from array elements 46, 48, 50, and 52, coupled through their respective phase shifters are amplified by low noise amplifiers 54, 56, 58, and 60, associated respectively therewith. The outputs of amplifiers 54, 56, 58 and 60 are combined by a corporate feed 62 and are coupled to a receiver or detector 64. Output base band signals from receiver or detector 64 are coupled to a signal processor 68 controlled by microcomputer 32.
Microcomputer 32 controls phase shifters 38, 40, 42 and 44 via an address decoder 70 and latches 72, 74, 76, and 78 associated one each with the phase shifters. Data from microcomputer 32 appears in serial fashion on an address bus 80 coupled to address decoder 70. The serial data is latched into latches 72, 74, 76 and 78 and then is transferred to an associated driver 82, 84, 86 and 88 on a single clock pulse. Thus, the phase of each of phase shifters 38, 40, 42 and 44 is shifted simultaneously.
Similarly, the individual gains of low noise amplifiers 54, 56, 58 and 60 are controlled by microcomputer 32 via address decoder 70, latches 90, 92, 94, and 96 and individual digital to analog converters 100, 102, 104 and 106, associated one each with the low noise amplifiers. Serial data from microcomputer 32 is decoded by address decoder 70. Latches 90, 92, 94 and 96 latch the serial information in place and on a single clock pulse the information latched is transferred simultaneously from all latches to the digital to analog converters. Thus, the gains of the low noise amplifiers are changed simultaneously. A DC power network 110 shown in dotted line, distributes power to all active circuit elements. A data output line 112 provides a means for connection to an external sensor or to another microcomputer. A command input line 114 provides an input from an external source such as an operator or another microcomputer. Array elements 46, 48, 50 and 52 are of the general type known in the art, even though not previously fabricated as part of a totally integrated microwave system. Specific examples of array elements 46, 48, 50 and 52 are detailed in U.S. Pat. No. 3,811,128 entitled "Electronically Scanned Microstrip Antenna" and U.S. Pat. No. 3,921,177 entitled "Microstrip Antenna Structures and Arrays", commonly owned with the present patent. These two patents are incorporated herein by reference to avoid unnecessary lengthy discussion.
Referring now to FIG. 2 there is shown a second embodiment of the monolithic microwave integrated circuit according to the present invention. As previously stated, this figure is a block diagram of a transmitting array corresponding to the receiving array shown in FIG. 1. In essence, the transmitting array is configured by exchanging the locations of the phasing networks and amplifiers shown in FIG. 1. In addition, the amplifiers 54, 56, 58 and 60 of FIG. 1 are replaced by voltage controlled power amplifiers 120, 122, 124, and 126; and receiver or detector 64 is replaced by a signal source 128. Otherwise, the remaining elements of FIG. 2 are identical to those of FIG. 1.
Referring now to FIG. 3, there is shown in schematic diagram, a third embodiment of the monolithic microwave integrated circuit according to the present invention. It illustrates a possible application of the underlying concepts of the monolithic microwave integrated circuit to the visible light spectrum of 10 5 -10 6 GHz. Receiving array elements 150 would gather visible light, such as solar energy, which would be converted into direct current by diode networks 152. The power from each of diode networks 152 would be "summed" by a DC power collection network 154 and delivered to an output terminal 156. All of the elements are integrated onto a common substrate 160. Ground 158 is a continuous (e.g. the metalized back surface of the substrate). Arrays such as this can be used to form even larger arrays since the gain and hence the collected energy is proportional to [4π (AREA) ]
SEMICONDUCTOR MEDIUM
The presently preferred embodiments of the monolithic microwave integrated circuit shown in FIGS. 1 and 2 are fabricated on semi-insulating gallium arsenide (S.I. GaAs). However, other media, such as silicon and/or GaAs on sapphire represent potential alternatives. At this time, only silicon and gallium arsenide present possible practical choices for X-band application because the processing technologies for these media are sufficiently mature so that consistent, repeatable results may be achieved at microwave frequencies. Other Groups III-V semiconductor compounds having better theoretical band gap and carrier mobility characteristics may ultimately be well suited for millimeter and submillimeter applications, but at the present time neither the material nor processing technology for these compounds has been sufficiently developed to provide the uniformity required for mass production. As a result the presently preferred embodiments, set forth herein, utilizes semi-insulating GaAs, with silicon being the only presently possible alternative but which, in turn, has been found impractical for reasons discussed below. This therefore leaves semi-insulating GaAs substrate material as the only presently known practical possibility. This substrate material is itself already known in the prior art having a resitivity in the range of about 10 7 to 10 9 ohm-cm.
In further consideration of the semiconductor medium, PIN diodes fabricated in planar, mesa and beam-lead configurations have been successfully used as switching elements at X-band microwave frequencies and above for over a decade in "bolt together" systems. These devices are made from the highest quality bulk silicon with cutoff frequencies in excess of 2000 GHz. Silicon, however, has a maximum resistivity of only 200-300 ohm-cm undoped. The loss tangent of silicon is therefore many orders of magnitude worse than that of standard microwave substrate materials such as quartz, alumina and sapphire. Typical microstrip transmission lines on silicon have losses of several dB/cm. Thus, the dielectric losses in a microstrip radiator on bulk silicon would reduce aperture efficiency to 20%, which is impractical.
The use of a silicon on sapphire (SOS) medium would eliminate this loss problem by allowing the microwave radiator and feedline to be fabricated on the sapphire dielectric leaving silicon only in small areas where PIN diodes need to be fabricated. This would solve one problem but create another. To date the achievable electron mobility, μn, in SOS epitaxial layers is less than that of bulk silicon. Therefore, PIN diodes suitable for X-band switches are not practical.
Another negative aspect of silicon is that low noise amplifiers are impractical at X-band. This is significant because the ultimate benefits of monolithic microwave integrated circuits and antennas could not be realized in silicon at this frequency.
MICROSTRIP RADIATORS
Microstrip radiators 46, 48, 50 and 52 are fabricated as a metallization adjacent to the semiconductor material. Layers of Ti-Pt-Au are deposited sequentially on the semiconductor material. The final metalization layer of Au should be at least four (4) skin depths thick at the operating frequency to prevent excessive ohmic losses in the microwave conductors.
In conventional microstrip radiator designs such as illustrated by U.S. Pat. No. 3,811,128 entitled "Electrical Scanned Microstrip Antenna" and U.S. Pat. No. 3,921,177 entitled "Microstrip Antenna Structures and Array", the choice of a dielectric or substrate material is based on tradeoffs involving physcial size and efficiency. As an example conventional hybrid microwave integrated circuits are often configured on high dielectric constant substrates with small conductors in order to minimize physical size. Circuit losses in the "bolt together" systems are often not critical since amplification stages can be liberally incorporated. Conversely, microstrip antennas, phasing networks and corporate feed networks are typically restricted to utilizing low dielectric constant materials such as teflon-fiberglass and employ larger conductors to achieve minimum loss, hence maximum gain.
In the presently described monolithic microwave integrated circuit, however, these traditional tradeoffs are overshadowed by totally different requirements imposed by the semiconductor device. Since the performance of a semiconductor component is uniquely related to the physical properties of the material, radiators 46, 48, 50 and 52 are adapted to the semiconductor medium without compromising element performance, i.e., radiation efficiency.
This adaptation is important because high efficiency, typically 90-95%, is an inherent "no-cost" characteristic of microstrip radiators. If this efficiency is inadvertently sacrificed, an amplifying component with its attendant increase in dc power will be required to recover the lost aperture gain. Such a trade-off is not at all attractive and therefore has been avoided.
Alternative microstrip radiators using quartz, alumina and sapphire substrates were tested as alternatives for the fabrication of radiators 46, 48, 50 and 52. Optimum performance was obtained for sapphire elements. The E-plane half-power beamwidth of the sapphire radiator was 126 degrees, as shown in FIG. 4, which is a computer plot of experimentally measured data. This half power beamwidth is desirable for phased array applications since the element factor does not degrade severly at large scan angles. Such broad beamwidths are characteristic of microstrip elements on high dielectric constant materials, and are explained by the examples shown in FIGS. 5 and 6.
Referring now to FIGS. 5 and 6, there are shown cut-away side views of microstrip radiators showing half power beamwidths of 90° and 126°, respectively. In essence the microstrip element is a two slot radiator and the dielectric under the patch can be treated as a low impedance transmission line λ/2 long connecting slot A and slot B. The half-wavelength property of this transmission line is determined by the dielectric constant of the material, however, the radiated field is a function of the slot separation in terms of free-space wavelength. A typical element on teflon-fiberglass dielectric, r=2.2, is shown in FIG. 5 and has a half power beamwidth of 90°. A comparable element on sapphire, r=9.39 is shown in FIG. 6. The resonant dimension or slot separation is reduced due to the higher dielectric constant resulting in a smaller aperture, hence broader beamwidth. It is also significant to note that the aperture efficiency of the same sapphire element determined by integration of the far-field radiation patterns is in excess of 93%.
The sapphire element has a 2:1 VSWR bandwidth of 9.5% which is substantially greater than the typical 1-3% bandwidths associated with designs on lower dielectric materials.
Similar performance is obtained on slightly higher dielectric constant materials such as the semi-insulating (S.I.) GaAs with r=12.6 utilized in the preferred embodiment. Efficiency is slightly degraded since the loss tangent of S.I. GaAs having a resistivity of 10 8 ohm-cm is equivalent to that of 99.6% AL 2 0 3 or Alumina. The loss tangents for sapphire (mono-crystalline AL 2 0 3 ) and S.I. GaAs or Alumina are 2 ×10 -5 and 1 ×10 -4 respectively Although these values are nearly an order of magnitude apart, the additional loss due to increased dielectric dissipation is negligible since the term is only 1.5% of the conductor loss. The net result, then is that microstrip radiator aperture efficiencies on semi-insulating GaAs exceed 90%.
PHASE SHIFTER SWITCHING ELEMENTS
Referring now to FIGS. 7 and 8, there are shown respectively the physical structure and equivalent circuit of one of the single gate FET switches that are utilized as the switching elements of 4-bit phase shifters 38, 40, 42 and 44. FET switches provide low power consumption and are fabricated using ion implantation planar GaAs technology.
The single gate FET switch, as shown in FIG. 7, is turned on and off by application of the appropriate voltage to the gate electrode. The on state is achieved with the gate zero biased or slightly forward biased with respect to the switch terminals. The off state is achieved by biasing the gate beyond the channel pinch-off voltage (negative for the usual n-type depletion-mode GaAs FET). There is no bias applied to the switch terminals for the FET switch.
As a result, there is no distinction between source and drain electrodes in the conventional sense. Also, as in the case of the varactor switch alternative, there is no required sustaining power to hold the FET switch in either the on or the off state. The use of a three terminal (or 4-terminal in the case of the dual gate FET) device for switching greatly simplifies the application of switching bias since the need for dc blocking capacitors is eliminated.
In the on state, the single gate FET switch exhibits a small resistance which is the sum of the channel resistance plus the ohmic contact resistance of the switch terminals. For a 500 μm wide FET with n + implanted ohmic contacts and a pinch off voltage of about 7 volts, the on resistance can be reduced to about 5 Ωor less for a single gate switch and about 7 Ωor less for a dual gate switch. Lower on state resistance can be achieved by increasing the width of the switch for a corresponding decrease in resistance but with a resultant increase in shunt capacitance in the off state. The dual gate switch has additional resistance due to the additional channel length required for the second gate. The parasitic series inductance in the on state can be made negligible by integrating the switch into the transmission line. It may be desirable in some applications to intentionally introduce inductance by locating the switch in a section of transmission line away from the ground plane.
The current handling capability of the FET switch in the on state is limited by the drain saturation current which is of the order of 150 mA for the 500 μm wide FET considered earlier assuming zero gate bias. Therefore, if the FET switch is used to effectively short circuit a 50Ω transmission line, the power handling capability in the on mode is about 63 to 100 mW. This power handling capability is more than adequate for switching in a low power phase shifter.
In the off state, the FET switch is essentially non-conductive and the microwave impedance is dominated by the shunt capacitance across the switch terminals which is largely the fringing field capacitance through the semi-insulating GaAs substrate of the gap capacitor formed when the gate is completely pinched off. For a 500 μm wide switching FET, this shunt capacitance is of the order of 0.07 to 0.1pF. At 10 GHz the capacitance of the off switch is about 160Ω to 230Ω. Since the off resistance of the FET switch is very high, the dissipation is very small in this state, i.e. reflection coefficients with magnitude near one are obtained. Thus, some form of ballasting or loading may be required to balance the amplitude characteristics between the two switching states. The power handling capability of the switch in the off state is determined by the amplitude of the rf voltage swing which can be sustained across the switch without turning the FET on in one direction or the other. For a single gate switch, the FET will turn on if the bias between the gate and either switch terminal (ohmic contact) becomes less than the pinch off voltage. Thus, the maximum permissible voltage swing across the switch cannot exceed the excess gate bias beyond pinch off. For example, if the pinch off voltage is -7V and the gate is biased at -10V, the rf swing at the output of a single gate switch may not exceed 3V peak or 6V peak-to-peak or else the FET will turn on during negative excursions of the rf voltage. In this example, the power handling capability of the off single gate switch would be about 23 mW into a 50 line which is again entirely adequate for a low-power phase shifter.
The single FET switch utilized in the preferred embodiment has the advantages of ease of biasing, power handling capability, and compatibility with existing process technology. There is, in addition, another subtle advantage for the FET switch in terms of control of circuit parameters. The circuit parameters of the FET switch are almost completely defined by the geometry which is established by the photolithography process. For the varactor switch, however, the capacitance in the on and off states is determined by the doping profile, bias voltage, and junction area. Although excellent control is anticipated over doping profiles through the use of ion implantation processes, the FET switch would be expected to hold an advantage in tightness of parameter distributions which would result in superior circuit reproducibility.
PHASE SHIFTER CIRCUIT
The realization of a 4-bit shifter involves incorporation of the switching elements (FET switches in the preferred embodiment) into circuitry permitting the insertion phase of the phase shifter to be switched in binary increments (22.5°, 45°, 90° and 180°) while maintaining nearly constant input and output VSWR and amplitude uniformity independent of phase.
Referring now to FIG. 9, there is shown a schematic diagram of one of the four-bit phase shifters 38-44. The phase shifters utilize FET switching elements, as previously discussed, in a circuit using both switched line and hybrid coupled techniques. The 45° and 22.5° bits use a switched line configuration to reduce area while the 90° and 180° bits utilize a hybrid configuration.
There are alternative phase shifter circuits which may be appropriate to alternative embodiments. The following discussion relates in general to these various alternatives and to the guiding criteria that will aid in the design of other phase shifter circuits.
Referring now to FIG. 10, there is shown, as another example, a physical schematic of a quadrature hyrid coupler in a branch line configuration. The branch line coupler is limited in bandwidth to about 10 to 15 percent since the transmission match, 3 dB power split, and 90° phase shift is only realized for the frequency at which all line lengths are 90°.
The backward wave interdigitated coupler, shown in FIG. 11, gives the broadest phase-shifter bandwidth of all and can be made fairly compact in size. This arises from the fact that although the 3 dB power split is realized only at the center frequency, the 90° phase difference between the coupler output arms, the input match, and the directivity are theoretically frequency independent. Another advantage is that the device is comparatively small and can also be fabricated in a single plane. This coupler typically yields octave bandwidths when designed in stripline, but due to unequal even and odd mode phase velocities in microstrip line the bandwidth reduces to about 35 to 40 percent. Such bandwidth is more than adequate for element compatibility.
A configuration suitable for the 45° and 22.5° bits is shown in FIG. 12. The loaded-line phase shifter is particularly worth considering with regard to their potential for small size. The loaded line phase shifter offers good VSWR and constant phase shift up to 20 percent bandwidith, but is practically limited to 45° maximum shift for that bandwidth. The design of the loaded-line phase shifter is based upon two factors. First, a symmetric pair of quarter wavelength spaced shunt susceptances (or series reactances) will have mutually cancelling reflections provided their normalized susceptances are small. Therefore, a good match results regardless of the susceptance sign or value.
FABRICATION
The fabrication process begins with the lapping and polishing of the semi-insulating GaAs substrate to a plane parallel thickness compatible with microstrip propagation characteristics (typically 0.6 mm at 10 GHz). Several surface cleaning steps insure proper adhesion of deposited SiO 2 and metal layers required for masking during the ensuing ion-implantation. The process continues following the sequence depicted in FIG. 13.
Referring now to FIG. 13, there are shown the processing steps for fabricating one of the planar GaAs FET phase shifter elements. As shown in FIG. 13(a) the semi-insulating substrate is covered with SiO 2 and a suitable metal. Holes are opened and the SiO 2 is removed by dry etching. The N+implant is then performed. After the N+implant is performed, the metal and oxide mask is removed from the source in FIG. 13(b). Then the alignment mark is defined by ion milling, as shown in FIG. 13(c). After the alignment mark is defined, the resist and metal are removed. Nitride and oxide is deposited and the implantation anneal is performed, as shown in FIG. 13(d). After the implantation anneal is performed, the insulators are removed and ohmic contact holes are defined using conventional photolithographic techniques. AuGe-Pt is then deposited. FIG. 13(e) shows the device after AuGe-Pt has been deposited. As shown in FIG. 13(f), a layer of SiO 2 is deposited. The gate and ohmic contact holes are defined and the exposed SiO 2 is removed by plasma etching, after removal of the SiO 2 by plasma etching, Ti-Pt-Au is deposited and the gate and circuit path areas are defined using conventional photo resist technology, as shown in FIG. 13(g). Then the exposed metal is removed by ion-milling, as shown in FIG. 13(h).
In the processing step shown in FIG. 13(h), the microstrip transmission lines, radiating element and DC biasing interconnect metallization are formed using photolithographic procedures. At this point RF blocking chokes or eventually lumped element components are simultaneously defined.
The use of ion implantation directly into high quality semi-insulating GaAs to form the active layer for planar FETs places certain restrictions on the nature of the compensation method used to obtain the insulating properties. The following conditions must be met to allow to achieve successful implantation of an active layer:
1. The compensating impurities and defects in the substrate must not affect the electrical properties of the ion implanted layer, so that carrier concentration, mobility, carrier lifetimes, etc., depend only on the identity and dose of the implanted purity. Meeting this condition ensures that the electrical properties of the implanted layers are independent of the substrate, and guarantees that the implanted layers can be prepared reproducibly.
2. Unimplanted portions of the semi-insulating substrate must retain their high resistivity after a wafer has been capped and annealed to remove damage in the implanted portions, so that electrical isolation is maintained between the doped pockets.
3. The substrate must be homogeneous. This implies that conditions 1 and 2 must be met with a minimum of short or long-range inhomogeneities or defects. In addition to homogeneity, flatness requirements on the wafers will be stringent for uniform small geometries and high density.
As previously stated the semiconductor material is semi-insulated GaAs, chromium (Cr) compensated (doped) grown by the horizontal Bridgman technique. The crystalline quality of the horizontal Bridgman grown ingots are superior with regard to low percipitate density, dislocation density and strain. Electrical compensation is routinely obtained with low Cr concentrations of 5 ×10 15 cm -3 . The initial uncompensated background doping is often as low as 8 ×10 14 cm -3 .
In order to obtain a high level of reproducibility, the GaAs may be qualified by a procedure such as that set forth in U.S. Pat. No. 4,157,494 --Eisen et al (1979).
Thus, there has been provided a monolithic microwave system including an integral array antenna. Of course, various alternative embodiments will be apparent to those of ordinary skill in the art having the benefit of the teachings set forth herein. Therefore, such alternate embodiments are intended to be within the scope of the appended claims.
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A monolithic microwave integrated circuit including an integral array antenna. The system includes radiating elements, feed network, phasing network, active and/or passive semiconductor devices, digital logic interface circuits and a microcomputer controller simultaneously incorporated on a single semi-insulating GaAs substrate by means of a controlled fabrication process sequence.
The resulting integrated circuit structure built upon a semi-insulating GaAs substrate provides a unique monolithic structure capable not only of phase-shifting, amplifying or otherwise controlling and conducting r.f. electrical signals but also capable of directly radiating/receiving r.f. electromagnetic emanations propagated to/from the integral antenna elements of the monolithic structure.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority of European Patent Application No. 03405454.4, filed on Jun. 23, 2003, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to an arrangement for the optional forming of stacks from several products, conveyed successively along a conveying path, and/or for changing the sequence of products, conveyed successively along a conveying path, the arrangement comprising a conveying device for conveying the products and at least one lifting apparatus for picking up the products along the conveying path from the conveying device and subsequently depositing them, wherein the lifting apparatus is designed as an up and down moving lifting element which picks up the products from the underside.
An arrangement of the aforementioned type has been in use at the Axel Springer Publishing House in Darmstadt, Germany, for processing stacked printed products.
The aforementioned arrangement consists of a narrow conveying belt, extending across a table, on which stacks are formed from bundled magazines. For this, a separate, height-adjustable fork is provided on both sides of the conveying belt and this fork is inserted underneath the magazine bundles, which project on both sides over the conveying belt that is stopped during the stacking operation, and lifts up these bundles. Thus, the lifted-up magazine bundle can then be lowered onto the subsequently arriving bundle during the following conveying step. The forks, which are arranged opposite each other on both sides of the conveying belt, are lifted up jointly by means of a synchronously driven toothed belt.
SUMMARY OF THE INVENTION
It is an object of the present invention to create a simple arrangement that allows the forming of a stack consisting of several products during a shorter cycle time.
The above and other objects are achieved according to the invention by the provision of an arrangement for an optional forming of stacks of multiple products conveyed successively along a conveying path, and/or for changing the sequence of products conveyed successively along the conveying path, the arrangement comprising: a conveying device having conveying sections for transporting the products in a conveying direction; and at least one up and down movable lifting element disposed on at least one side of the conveying device and which picks up the products from an underside of the products along the conveying path from the conveying device and subsequently deposits them again, the lifting element being disposed at a right angle to the conveying direction and being displaceable below a support surface of the conveying device.
To be able to grip products with differently large deposit surfaces from the underside, the lifting element is provided with several support rods that project evenly spaced and at right angles to the conveying direction from a support.
It is advantageous if two separately controlled and/or driven lifting elements are arranged on opposite sides of the conveying device, which make it possible to achieve a higher output.
The conveying device preferably is a working section of a circulating conveying belt, the support surface of which is interrupted several times in the operative range of the lifting element, so that the support rods can be inserted.
A simple measure for creating interruptions in the support surface is to have conveying belt sections that are deflected below the support surface and back.
The deflected sections of the conveying belt are advantageously formed by rolls that can be jointly lowered, thus creating a downward extending loop into which the support rods of the lifting element are inserted, such that they are positioned below the level of the support surface of the conveying section.
If the arrangement is not in use, the rolls that form the interruptions in the support surface can be lifted out jointly, thus resulting in a continuous conveying section of the conveying device.
A tensioning device, connected to the conveying belt, can function as simple means for removing the interruptions in the support surface through re-tensioning of the conveying belt once the rolls are lifted out.
Alternatively, the support surface of the conveying device can be formed by driven conveying rolls, arranged transverse to the conveying direction, wherein individual conveying rolls can be lowered to form interruptions in the support surface.
To secure the products during the stacking, a format-adjustable vertical guide is provided above and/or at the upper end of the lifting element, into which the products, lifted up from below for the stacking operation, are inserted.
It is advantageous if one position for gripping the products is arranged below the vertical guide on the support surface, such that the products can be lifted up perpendicular.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained with the aid of an exemplary embodiment and with reference to the drawing, to which reference is made for all details not further mentioned in the description.
FIG. 1 is a schematic view from the side of the device according to the invention.
FIG. 2 is a schematic view from the side of the device according to FIG. 1 , with raised mechanisms and raised intake rolls.
FIG. 3 is a view of the arrangement in transporting direction F in FIG. 1 , with the lifting elements inserted into the conveying path;
FIG. 4 is a view of the arrangement according to FIG. 3 , with extended lifting elements;
FIGS. 5A-5F show a stacking operation of the arrangement, in a step-by-step representation.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an arrangement 1 for forming predetermined stacks from several products 2 , which can be stacked one above the other and are conveyed successively in the direction or arrow F. This arrangement can also be used for changing the sequence in which the products 2 are conveyed successively along a conveying path. The products can be stackable goods, such as bundles, individual magazines, brochures, books, work pieces or the like. The products 2 are conveyed with the aid of a conveying device 3 , and are lifted up at a location along the conveying path where a stacking device 4 is positioned. Several arrangements 1 can also be arranged along the conveying path, wherein products 2 can be transported and lifted up either continuously or discontinuously.
For the purpose of lifting products 2 off conveying device 3 , the latter is provided with a conveying element 5 which forms a conveying section of the conveying path. This conveying element 5 is at least as long as the longest products to be stacked. At least one conveying section 6 for feeding products 2 is installed upstream of conveying element 5 while a conveying section 7 or a different processing station can be installed downstream of this element.
Conveying element 5 is an endless conveying belt 10 that circulates around two spaced-apart deflection rolls 8 , 9 and forms a support surface 11 by means of a conveying belt section for products 2 to be transported. Support surface 11 is interrupted by respective roll pairs 12 , around which conveying belt 10 is deflected so as to form a downward loop 13 . Of these roll pairs 12 , at least two pairs are arranged (evenly) distributed over the length of the effective product pickup area, wherein FIG. 1 shows four roll pairs 12 of this type. Each belt loop 13 is respectively created through one intake roll 14 which pulls conveying belt 10 via a roll pair 12 from a stretched position (see FIG. 2 ) downward. The four intake rolls 14 , used for the exemplary embodiment shown in FIGS. 1 and 2 , are respectively positioned with each end in a respective joint roll support 15 , 16 that is arranged to the side of the conveying element 5 (see also FIGS. 3 and 4 ).
Conveying belt 10 is tensioned with a tensioning device 18 which acts upon an empty belt section 17 . For this, the conveying belt 10 moves around two tensioning rolls 19 , 20 , arranged in the manner of pulleys, and a deflection roll 21 after and/or before conveying belt 10 has been deflected around deflection rolls 22 , 23 in a vertical direction. Conveying belt 10 is respectively pre-tensioned with a tensioning force Z at rolls 19 , 20 .
Roll supports 15 , 16 are held by a holding device, not shown herein, below the level of supporting surface 11 , so that a lifting element 24 of a lifting apparatus 25 can be inserted below the support surface 11 into belt loops 13 .
The lifting apparatus 25 furthermore comprises a support 26 , guided on a frame 27 , such that it can be adjusted in a perpendicular direction and can be secured. Support rods 28 are attached on one end to support 26 such that they project in the manner of an extension arm from a side into an area of operation of lifting apparatus 25 . FIG. 1 shows a lifting element 24 , consisting of four support rods 28 , which make it possible to pick up products 2 or packages even considerably shorter than the fork-type lifting element.
FIG. 2 shows arrangement 1 in the form of a simple conveying device 3 , with a continuous support surface 11 , wherein lifting apparatus 25 , and lifted-out intake rolls 14 are in a non-operational position above conveying surface 11 . To achieve the non-operational position, lifting apparatus 25 including support 26 and lifting element 24 , and roll supports 15 , 16 are connected to a motor-driven (not visible herein) lifting mechanism that places lifting apparatus 25 and roll supports 15 , 16 into the position shown in FIGS. 1 and 2 . Once intake rolls 14 are moved out of belt loops 13 , conveying belt 10 is re-tensioned with tensioning device 18 to form a continuous, level support surface 11 above the roll pairs 12 .
As a result, the arrangement 1 is partially turned off and can be operated simply as a conveying element for conveying device 3 .
Of course, it is also possible to install several arrangements 1 along a conveying device 3 .
FIGS. 3 and 4 show arrangement 1 as seen in transporting direction F wherein intake rolls 14 that form belt loops 13 are located below support surface 11 of conveying belt 10 , meaning the support surface 11 has gaps into which support rods 28 of lifting element 24 of lifting apparatus 25 can be inserted.
FIGS. 3 and 4 illustrate an arrangement 1 with two driven lifting elements 24 , 29 of respective lifting apparatus 25 , 30 , wherein these lifting elements are positioned opposite each other on both sides of conveying device 3 and/or conveying element 5 and can be driven to move up and down on frame 27 . Each lifting apparatus 25 , 30 can thus be driven along frame 27 independent of the other one. Support rods 28 of lifting elements 24 , 29 respectively can be displaced jointly in the manner of a telescope from an operating position, where they are located above conveying element 5 , to a non-operating position on the side of the conveying element. Respectively one pneumatic cylinder 31 associated with each lifting apparatus 25 , 29 is provided for this, as indicated. Naturally, a mechanical device could be provided for the same purpose. As for the height adjustment of a lifting apparatus 25 , 30 , there may be provided a lifting mechanism, in the form of a toothed belt (not shown) that runs around a lower or an upper roll (not shown) and which is attached at both ends to support 26 of lifting elements 24 , 29 . The height-adjustable lifting element 24 , 29 is respectively guided along two vertical posts 27 that project through support 26 .
A vertical guide 32 is arranged above the support surface 11 , at the maximum height for the up and down moving lifting elements 24 , 29 , on which one or several products 2 can be positioned one above the other for maintaining their position during the stack forming. The vertical guide 32 is designed such that it can adjust to the corresponding products 2 to be stacked.
The mode of operation for arrangement 1 for stacking products is explained in the following with the aid of FIGS. 5A to 5F . In FIG. 5A , a stack of products 2 has been lifted off support surface 11 with the aid of lifting element 29 of lifting apparatus 30 and has been positioned in vertical guide 32 . In the meantime, a following product 2 ′ on conveying element 5 is available for pickup by lifting element 24 of lifting apparatus 25 that is inserted into the gaps formed by belt loops 13 in support surface 11 or is in the process of passing by stacking device 4 .
According to FIG. 5B , product 2 ′ is lifted up with lifting apparatus 25 from the conveying element 5 and is raised to below the lifting element 29 and/or its support rods 28 . Product 2 ′ preferably does not make contact with the underside of support rods 28 , so that it will not be displaced in the compound stack on support rods 28 of lifting element 25 when support rods 28 of lifting element 29 are pulled out.
In the following step ( FIG. 5C ), lifting element 29 underneath product 2 is pulled out to the side, so that the latter, which is secured on the side of vertical guide 32 , comes to rest on top of the product 2 ′ underneath. Immediately following this, both products 2 and 2 ′ are lifted up further, until lower product 2 ′ has reached the vertical guide 32 .
According to FIG. 5D , a product 2 ″ subsequently reaches the position where it is picked up by the stack-forming device 4 , below vertical guide 32 on conveying element 5 , where it is awaited by lifting element 29 of lifting apparatus 30 that has meanwhile been lowered below the support surface 11 . This third product 2 ″ is then lifted up to below the packet consisting of the upper product 2 and lower product 2 ′, in the same way as the product 2 ′ (see FIG. 5E ).
Following this, lifting element 24 is again removed again from the stack, so that three stacked products 2 , 2 ′ and 2 ″ rest on the support rods 28 of lifting element 29 .
The finished packet and/or the stack consisting of three products 2 , 2 ′ and 2 ″ is then lowered with lifting apparatus 30 onto support surface 11 of conveying element 5 and is thus transported further along conveying device 3 ( FIG. 5F ).
The forming into stacks is carried out with a control (not shown herein), which is connected to a programmable computer. With the aid of a processing program in the computer, the device 1 can automatically form product stacks from the supplied products 2 , 2 ′, 2 ″. The arrival of the supplied products 2 , 2 ′, 2 ″ is determined, for example, with sensors installed in front of device 1 , so that a fully automatic stack-forming operation is created. Products 2 , 2 ′, 2 ″ to be stacked are determined with the aid of the computer program, meaning individual products 2 can also pass through the device 1 without being stacked.
The product stacks or individual products can then be packaged or hoop-encased downstream of device 1 and can subsequently be addressed and/or delivered to a palletizer for shipping.
For a precise positioning of the products in the device 1 , an end stop (not shown herein) which can be raised to above the support surface 11 , can also be used on the transport path upstream of the device 1 .
The invention has been described in detail with respect to exemplary 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.
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An arrangement for an optional forming of stacks of multiple products conveyed successively along a conveying path, and/or for changing the sequence of products conveyed successively along the conveying path. The arrangement includes a conveying device having conveying sections for transporting the products in a conveying direction. At least one up and down movable lifting element is disposed on at least one side of the conveying device and picks up the products from an underside of the products along the conveying path from the conveying device and subsequently deposits them again. The lifting element is disposed at a right angle to the conveying direction and is displaceable below a support surface of the conveying device.
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BACKGROUND OF THE INVENTION
This invention relates to a method of and apparatus for oxidizing p-xylene, and in particular, to the use of an induced flow loop reactor for the oxidation of p-xylene and/or p-methyltoluate.
Various reaction sequences, methods, and apparatus for the oxidation of p-xylene, p-toluic acid, and esters thereof, to form terephthalates including dimethylterephthalate (DMT), are known. For example, U.S Pat. No. 4,185,073, teaches an apparatus for continuous production of terephthalic acid by catalytic air-oxidation of p-xylene in a benzoic acid-water liquid solvent system. U.S. Pat. No. 3,923,867, teaches a method of producing high purity monomethylterephthalate by oxidation of p-xylene. Various methods of producing terephthalic acid from p-xylene are taught in U.S. Pat. Nos. 3,513,193; 3,887,612; and 3,850,981.
The oxidation products of p-xylene have wide commercial and industrial application, particularly in the production of polyester fibers and films. Industrial-scale methods and apparatus for oxidation of p-xylene are known, but none to date achieve high yields and good temperature control utilizing relatively simple and inexpensive equipment.
Moreover, in each of the aforementioned patents, mechanical agitation means is utilized during oxidation. Not only do they require costly energy, i.e. utilities, to operate, but have the additional disadvantages of moving parts within the reactor, such as mechanical breakdowns. Other currently used oxidation reactors in which agitation is not provided suffer from significant temperature variations within the reactor and/or poor heat transfer characteristics, resulting in increased operating costs and lower product quality.
Reactors wherein circulation is induced without the need for an outside power source, e.g. electricity, or mechanical agitation are known. Liquid phase reactors, wherein the introduction of a gas to one part of the reactor induces circulation due to density differentiations, have been utilized for contacting liquid and solid particles. For example, U.S. Pat. No. 3,759,669, teaches a reactor with concentric reactor legs, in which introduction of gas maintains catalytic particles in suspension without the need of a circulating pump system. U.S. Pat. No. 3,552,934, uses a partition head with a plurality of channels to separate two such reactor legs or zones. U.S. Pat. No. 3,124,518 teaches a reactor configuration for hydrogenation, wherein the introduction of hydrogen induces the necessary circulation without mechanical agitation or stirring.
SUMMARY OF THE INVENTION
In accordance with the present invention, p-xylene is oxidized to p-toluic acid and/or p-methyltoluate is oxidized to monomethylterephthalate (MMT) at high circulation rates in an induced flow reactor loop without mechanical agitation or pumping. The circulation achieved by design of the reactor and the manner and amount of oxygen-containing gas-introduction into the reactor permits an essentially isothermal operation. Maximum temperature variation within the reactor can be limited to about 3°-5° F.
The oxidation of p-xylene and/or p-methyltoluate (PMT) can be effectively and efficiently carried out on a continuous basis as part of a continuous process for the production of DMT or other desirable end-products by utilizing an induced circulation reactor comprising two substantially vertical reactor columns or legs interconnected at their respective tops and bottoms by first and second interconnecting conduits or passages to form a "loop." According to the method of the present invention, oxidation of p-xylene and/or PMT is carried out in the presence of small amounts of catalysts in a reaction medium flowing through such a loop reactor by (a) introducing the liquid reactants, i.e. inputting p-xylene and/or PMT, into the loop through at least one liquid reactant inlet means; (b) introducing an oxygen-containing gas, such as air, into one of the two said reactor columns to gasify, i.e. reduce the density of, the reaction medium in this first reactor column through gas inlet means spaced below the top of said loop a vertical distance sufficient to cause circulation of the reaction medium through the loop, i.e. to cause the denser reaction medium in the other of said reactor columns to flow downward and the gasified, lighter reaction medium in said first reactor leg to flow upward; (c) inputting catalysts into the loop; (d) venting the excess gas from the top of the reactor loop to degasify, i.e. increase the density of, the reaction medium as it flows from said first reactor column to said second reactor column; and (e) cooling the reaction medium as it flows upward through the said first reactor column or downward through the second "downside" reactor column. The oxidate reaction products, i.e. p-toluic acid and/or monomethylterephthalate (MMT), are removed from the reactor, typically as overflow from the top of the reactor loop, at about the same rate of input as the liquid reactants.
More particularly, the reactor utilized in the method of the present invention operates as a liquid phase reactor with high liquid circulation rates without the need for mechanical agitation or pumping equipment. The motivating force for circulation is the difference in specific gravity or weight of the vertical interconnected reactor columns of the liquid reaction medium contained in the two legs of the reactor. One column contains a gas/liquid mixture while the other contains essentially ungasified liquid. The difference in specific gravity between the reaction medium in the first and second reactor columns is a result of the introduction of the oxygen-containing gas, such as air, to only the first or upside of the vertical reactor columns. The upside leg or column thus has a gasified section, whereas the other, i.e., the downside, reactor leg or column contains essentially only liquid reaction medium. Unreacted oxygen-containing gas and inerts are vented off the top of the loop, thereby effecting substantial removal of gases from the liquid reaction medium prior to its entering the downside leg. In the preferred embodiment, the non-gasified, or downside, portion of the loop, is in effect a tube and shell heat exchanger for removal of the heat of reaction. However, the tubular, i.e. the tube and shell, side can also be utilized as the gasified side, in which case it still functions to remove the heat of reaction, but then the flow is reversed and the liquid reaction medium flows up through the tubes as a result of the oxygen-containing gas being introduced through the gas inlet on the cooling or tubular side of the loop.
Significantly, by oxidizing p-xylene and/or PMT according to the method and apparatus of the present invention, the induced circulation through the reactor, including the heat exchange portion of the reactor, effected without mechanical agitation or stirring, is sufficient to maintain the point to point temperature variation in the reactor to less than 10° F. and often to within 3°-5° F. The excellent mixing achieved due to turbulent flow plus minimizing the temperature differential within the reactor results in high yields. Introduction of the gas in the appropriate amount and location results in adequate circulation, i.e. turbulent flow in the region of gas input plus a circulation through the heat exchanger sufficient to remove substantially all the heat of reaction and thus maintain a relatively constant temperature throughout the reactor and reaction medium.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut-away partial front view of a reactor utilized for the oxidation of p-xylene and PMT in accordance with one embodiment of the present invention.
FIG. 2 is a schematic flow sheet drawing of a process for producing DMT wherein oxidation of p-xylene and/or PMT is carried out according to the present invention.
FIG. 3 is a cut-away front view of a reactor utilized for the oxidation of p-xylene in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts one embodiment of a reactor useful for the oxidation of p-xylene and PMT, according to the present invention. The reactor 2 is an induced circulation "loop" reactor having first and second substantially vertical columns or legs, i.e. a first upside reactor column 4 and a second downside heat exchange column 6. The reactor columns 4 and 6 are interconnected at their tops and bottoms by connecting passages or conduits 12 and 13 to form a "loop." Liquid reactants, i.e. p-xylene and/or p-methyltoluate (PMT) and catalysts, are inputted to the reactor loop through p-xylene inlet means 10, PMT inlet means 11 and catalyst inlet means 21. Although the p-xylene inlet means 10 and the PMT inlet means 11 may be located anywhere in the loop, they are preferably not in the heat exchanger, and most preferably disposed upstream of the gas inlet means and near or about the bottom of the loop. Air or another oxygen-containing gas is inputted or introduced into said upside column 4 through gas inlet means 8, spaced from the top of the loop at a distance sufficient to induce the desired circulation, i.e. at least enough circulation through the heat exchange column 6 to permit the heat of reaction to be removed. Introducing gas into only one column of the loop gives the reaction medium in the reactor column 4 a lower density than that in the non-gasified column 6 thereby causing the reaction medium to circulate through the loop, upwardly in the first reactor column 4 and downwardly in the second reactor column 6. The excess gas and inerts are separated and exit the reactor through venting means 14 at the top of the loop, thereby allowing substantially degasified, and more dense, reaction medium to enter the downside column 6. Of course, by an appropriate relocation of the gas inlet the flow direction could be reversed to make column 6 the upside column and column 4 the downside column.
The downside column 6 is equipped with cooling means, such as the tube and shell heat exchanger 16 depicted in FIG. 1. In order to minimize the pressure drop through the reactor and to maintain the high circulation rate, the flow area of the heat exchanger 16 in the downside column 6 may be as large as or larger than the flow area, i.e. cross-sectional area, of the upside column 4.
The liquid-gas separation area 19 in the reactor 2 is typically but not necessarily above the downside column 6. In a reactor with a configuration such as that of FIG. 1, the liquid-gas interface 18 is preferably at about the same level as the top of the conduit or passage 12 interconnecting the tops of the reactor columns 4 and 6. The liquid oxidate comprising p-toluic acid and/or MMT can be removed from an oxidate outlet 20 disposed at about the same elevation as the top conduit 12 or alternatively about the bottom interconnecting conduit 13 as depicted in FIG. 1, but in either event should be on the down flow side of the reactor. The vertical distance between the interface 18 and the gas inlet means 8 is defined as the submergence level of the gas inlet 8. Typically the rate of circulation increases with submergence.
The consumption of oxygen during the oxidation reaction reduces the amount of gas reaching the top of the reactor loop. However, as will be known and understood by those skilled in the art, the circulation is not dependent upon gas reaching the top since the maintenance of any gasified section (height) will produce some degree of circulation. The taller the gasified section, i.e. the larger the submergence, the greater the circulation. A certain amount of the circulation rate can be attributed to the oxygen even though eventually much of it is consumed. The amount of inerts, such as nitrogen, present in the air feedstock will in any event create a high circulation rate within the reactor. The circulation rate through the heat exchanger will be sufficient to reduce the temperature variation within the reactor to about 5° F. When air is utilized as the oxygen-containing gas, the introduction of about 14.3 moles of air, i.e. about 3 moles of O 2 , per mole of p-xylene and/or PMT to be oxidized results in more than adequate circulation and heat removal. The force causing circulation is balanced by the pressure drop through the reactor. By per mole p-xylene is meant per mole of p-xylene, PMT and/or any other intermediate of p-xylene which is itself oxidized. Typical reaction conditions are, temperature of about 140° C. to about 170° C. and pressure of about 4 to about 8 atmospheres.
The inherently low pressure drop through the reactor of the present invention is a direct result of its novel design. The wall effects (friction) on the flow of the reaction medium are minimal because of the relatively large diameters of the reactor columns. The height to diameter ratio of the reactor column which does not include the heat exchanger may be from 3:1 to 100:1 depending on reactor capacity and is typically in the range of from 5:1 to 10:1. The heat exchange tubes 15 will have diameters larger than those normally utilized in chemical reactors, i.e. having an outside diameter of 1 to 3 inches, more preferably about 2 inches O.D. The relatively large diameters of the tubes allow turbulent flow conditions to be maintained in the tubes with a resulting high heat transfer efficiency. The number of such tubes will be primarily dependent on the total cross-sectional or flow area desired. The length of the tubes is dependent upon heat transfer considerations, i.e. the length will be sufficient to effect enough heat removal to maintain the reaction medium temperature constant to within about 10° F. and preferably within about 3°-5° F.
In accordance with the present invention, the heat of reaction is removed by indirect heat exchange with another liquid and/or gas. The heat exchange surfaces are incorporated into the reactor in such a way as to permit a substantially unimpeded flow of the circulation rate of the reaction medium. In addition, consistent with the present invention, heat transfer surfaces may be inexpensively provided since the rapid circulation and turbulent flow allow the heat transfer to be effected utilizing high temperature (pressurized) water.
The sizing of the reactor for any particular design capacity is based upon calculations of heat transfer requirements for removal of the heat of reaction, gas velocity and throughput rate, and reaction kinetics. In calculating the surface area of the heat exchanger tubes, the overall heat transfer coefficient is the key parameter. Depending upon the manner in which the entire reactor is designed, the overall heat transfer coefficient may vary from 30 to 80 BTU/hr/ft 2 /°F. Typically a coefficient of 50 to 60 BTU/hr/ft 2 /°F. will be achieved if the flow areas are designed in accordance with the parameters set forth herein. Assuming the heat exchanger is located in the nongasified leg of the reactor, the gasified leg is sized so that the superficial gas velocity in that leg is between 0.25 and 4 feet per second and preferably between 1 and 1.5 feet per second. The cross sectional flow area so calculated is the minimum flow area provided in the nongasified leg. Thus if the heat exchanger is in the nongasified leg, the total of the inside cross sectional areas of all the heat transfer tubes provided should equal or exceed the cross sectional flow area of the other leg.
Often it is most economical to use heat exchanger tubes which are 20 feet in length, although this length is by no means a requirement. If more flow area is required than would be provided with the number of 20 foot long tube required for the heat transfer requirement, a larger number of shorter tubes are used. In this way both the flow area and heat transfer surface requirements are met.
Generally a reactor designed on the basis of flow area and heat transfer requirements will contain enough liquid volume so that reaction kinetic requirements are met. However, if additional volume is required it is simply and economically obtained by increasing the height of the wide diameter sections above or below the heat exchanger.
In the embodiment depicted in FIG. 1, water at a temperature of 270° to 338° F. and a pressure of 27 to 100 psig. will enter the shell of the downside reactor column 6 through water inlet 30 and will flow around the tubes 15 carrying the liquid reaction medium 3. Heat from the reaction medium will cause the pressurized water to form steam which exits the shell at steam outlet 32.
Where the desired process end-product is DMT (dimethylterephthalate) a mixture of p-xylene and p-methyltoluate is oxidized with air in the presence of heavy metal catalysts to produce p-toluic acid and MMT (monomethylterephthalate). No reaction solvent is necessary during oxidation, although the reaction may be carried out in acetic acid. The catalyst may be cobalt acetate or a mixture of cobalt and manganese acetates. The p-xylene and p-methyltoluate are continuously oxidized at 140° to 170° C. and 4 to 8 atmospheres pressure with air. A small amount of catalyst may be continuously added to the reactor so as to maintain a constant catalyst concentration. It will be understood that a small amount of catalyst is continuously withdrawn from the reactor with the overflowing oxidate. The catalyst is added as a solution in water or acetic acid.
A small amount of terephthalic acid may be formed due to the reaction of p-toluic acid with oxygen (air). Any terephthalic acid formed will be insoluble. However, the amount of terephthalic acid formed is very small due to the relative ease of oxidizing p-xylene and p-methyltoluate. Any terephthalic acid formed will be maintained in suspension and will overflow out of the reactor with p-methyltoluate and a small amount of unreacted p-xylene.
Referring to FIG. 2, the overflowing oxidate leaving the reactor is first steam stripped to remove p-xylene which can be recycled to the reactor. The remaining oxidate is then esterified with methanol by conventional methods, such as taught by U.S. Pat. No. 3,923,867. The crude ester obtained is subsequently fractionated, whereby p-methyltoluate is recovered overhead for recycle to the reactor. The bottom of the fractionation is separated in another column into crude DMT and residue. The DMT is further purified by crystallization or other known methods.
As will be known and understood by those skilled in the art, a number of induced flow reactors of the present invention may be operated in series, i.e. the oxidate product out of the first reactor may feed a second reactor, and if desired, the overflow of the second may feed a third reactor. The reactor operates continuously with feedstock constantly added and liquid oxidate continuously withdrawn. However, when first put into operation, unless there is a supply of p-methyltoluate with which to fill the reactor, it will typically be filled with p-xylene. In such a case no fresh p-xylene would be added until a sufficient concentration of p-methyltoluate has been formed downstream in the process for recycling to the reactor.
FIG. 3 depicts an alternative configuration of the loop reactor wherein the upside reactor column 4 is inside and concentric with the downside heat exchange column. The loop of the reactor of FIG. 3 is thus configured like a vertically elongated donut with the liquid reaction medium moving upward through the center of the donut and downward through the sides. The numerals utilized in FIG. 3 are the same as those in FIG. 1 for corresponding elements of the reactors.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, which are nevertheless within the scope of the invention and are intended to be understood as falling within the meaning and range of equivalents of the appended claims.
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A novel vertical induced circulation reactor is utilized to carry out the oxidation of p-xylene and p-methyltoluate with air in the presence of a catalyst to produce p-toluic acid and monomethylterephthalate (MMT). A novel method for preparation of dimethylterephthalate (DMT) is provided wherein the p-toluic acid and MMT formed according to the invention are esterified by conventional means in the presence of methanol to produce p-methyl toluate and dimethylterephthalate (DMT), respectively, the p-methyl toluate being recycled to the reactor as a reactant stream.
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FIELD OF THE INVENTION
The invention relates generally to the field of photography, and in particular to cameras. More specifically, the invention relates to a variable format viewfinder mask and lens cover in a camera.
BACKGROUND OF THE INVENTION
Reloadable and recent one-time-use cameras for the new "Advanced Photo System" give you not just one print format, but a choice of three. For the classic proportions of a 35 mm print, the photographer chooses the "C" format. For a wider view, the full-frame "H" format is chosen. And for an even wider look, the "P" format is chosen to provide a sweeping panoramic print. The camera records the choice of print format magnetically and/or optically on the filmstrip for each exposure. The photofinisher's equipment then reads this data, and automatically prints each print in the selected "C", "H" or "P" format. A "C" format print is typically 4×6 inches. An "H" format print is typically 4×7 inches. And a "P" format print is typically 4×10 inches or 4×11.5 inches.
No matter which format is selected in the camera, "C", "H" or "P", the exposed image areas on the filmstrip are always in the "H" format. This allows re-prints to be made in any of the three formats rather than just in the selected format.
In order for the photographer to know how much of the subject being photographed will be included in the "C", "H" or "P" format print, the viewfinder in the camera includes a variable state masking device, such as a mechanical masking blade or an electronic masking liquid crystal display, for framing the subject according to the particular format that is selected. A manually operated format selector is provided to change the state of the masking device to the view the desired format in the viewfinder. This is shown, for example, in U.S. Pat. No. 4,973,997 issued Nov. 27, 1990.
In inexpensive reloadable cameras and one-time-use cameras, implicity of the variable state masking device and the manually operated format elector is an ever-present goal.
SUMMARY OF THE INVENTION
A camera comprising a viewfinder for viewing a subject to be hotographed, a masking a device for the viewfinder having a number of different format mask configurations, a taking lens for forming an image of the subject, and a lens cover for the taking lens, is characterized in that:
the masking device and said lens cover are supported to be moved at the same time for any one of the mask configurations to be in a masking position partially masking the viewfinder when the lens cover is not covering the taking lens and for every one of the mask configurations to be respective non-masking positions not partially masking the viewfinder when the lens cover covers the taking lens.
Preferably, the masking device and the lens cover are united to form a single piece.
Also, the camera includes a flash switch that is capable of changing state to energize an electronic flash, and the single piece includes a number of switch actuators whose particular number is one more than the number of the mask configurations for individually changing the state of the flash switch to energize the electronic flash as the single piece is moved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded front perspective view of a one-time-use camera according to a preferred embodiment of the invention;
FIG. 2 is an exploded rear perspective view of the one-time-use camera shown in FIG. 1; and
FIGS. 3-8 are front elevation views of the one-time-use camera depicting operation of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention is disclosed as being embodied preferably in a one-time-use camera. Because the features of a one-time-use camera are generally known, the description which follows is directed in particular only to those elements forming part of or cooperating directly with the disclosed embodiment. It is to be understood, however, that other elements may take various forms known to a person of ordinary skill in the art.
Referring now to the drawings, FIGS. 1 and 2 show a one-time-use camera 10 comprising a plastic opaque main body part 12, and a pair of plastic opaque front and rear cover parts 14 (rear cover part not shown) which connect to one another to house the main body part between them in order to complete the camera assembly. The main body part 12 is adapted to be nested in the front cover part 14, and the rear cover part is intended to be fitted to the main body part 12 to make the main body part light-tight.
As shown in FIGS. 1 and 2, the main body part 12 has a pair of cartridge receiving and unexposed film roll chambers 16 and 18 for a known "Advanced Photo System" film cartridge 20 and for an unexposed film roll coiled about a film supply spool (not shown). The cartridge receiving and unexposed film roll chambers 16 and 18 are located at opposite sides of a backframe opening 22 in which successive frames of a filmstrip 24 are exposed during picture-taking. The filmstrip 24 is originally on a cartridge spool (not shown) inside the film cartridge 20, but for the most part is pre-wound onto the film supply spool during camera manufacture. After each picture is taken, the exposed frame of the filmstrip 24 is wound onto the cartridge spool inside the film cartridge 20 and the next unexposed frame is drawn off the unexposed film roll and to the backframe opening 22.
The main body part 12 supports various known camera components which are connected to the main body part before the main body part nested in the front cover part 14 and the rear cover part is fitted to the main body part. These camera components are a taking lens 26 for forming an image of a subject being photographed; a viewfinder 28 for viewing the subject and including a pair of optically aligned front and rear viewfinder lenses 30 and 32; a manually depressable shutter release button 34 for releasing a pivotally mounted shutter blade (not shown) behind the taking lens; a manually rotatable thumbwheel 36 for engaging one end of the cartridge spool (not shown) in order to wind an exposed frame of the filmstrip 24 into the film cartridge 20 after each picture is taken and to move an unexposed frame from the unexposed film roll on the film supply spool (not shown) to the backframe opening 22 for the next exposure; and an electronic flash 38 including a flash circuit board 40, a flash capacitor (not shown) located behind the circuit board, a flash emission lens 42, and a flash battery 44. Details of the flash circuitry are provided in prior art U.S. Pat. No. 5,574,337 issued Nov. 11, 1996.
As shown in FIGS. 1 and 2, a combination lens cover for uncovering/recovering the taking lens 26 and masking device for partially masking/completely masking (covering) the front viewfinder lens 30 is a single piece disk 46 which is rotatably supported on an axial pin 48 that is located in respective bearing pin-holes 50, 52 and 54 in the single-piece disk, the front cover part 14 and the main body part 12. The single-piece disk 46 has three different format rectangular-shaped mask openings 56, 58 and 60 and three identical rectangular-shaped lens openings 62, 64 and 66. The different format mask openings 56 and 58 are spaced ninety degrees apart; the different format mask openings 58 and 60 are spaced ninety degrees apart; and the different format mask openings 56 and 60 are spaced one-hundred eighty degrees apart. The identical lens openings 62, 64 and 66 are arranged radially inward of the respective mask openings 56, 58 and 60 about the axial pin 48.
The respective mask openings 56, 58 and 60 have the standard "C" format, i.e. classic, the standard "H" format, i.e. substantially full frame, and the standard "P" format, i.e. panoramic, aspect ratios. See FIGS. 1-6. The single-piece disk 46 is intended to be manually rotated to locate any one of the "C" format, "H" format and "P" format mask openings 56, 58 and 60 in a partial masking position over a rectangular-shaped front viewfinder opening 68 in the front cover part 14 which is for the front viewfinder lens 30. This is done in order to frame a subject to be photographed in accordance with the desired "C", "H" or "P" format. As shown in FIG. 3, when the "C" format mask opening 56 in the single-piece disk 46 is in the partial masking position over the front viewfinder opening 68 in the front cover part 14, the lens opening 62 in the single-piece disk is over a circular-shaped lens opening 70 in the front cover part which is for the taking lens 26. Thus, the taking lens 26 is uncovered when the "C: format mask opening 56 is in the partial masking position. As shown in FIG. 4, when the "H" format mask opening 58 in the single-piece disk 46 is in the partial masking position over the front viewfinder opening 68 in the front cover part 14, the lens opening 64 in the single-piece disk is over the lens opening 70 in the front cover part. Thus, the taking lens 26 is uncovered when the "H" format mask opening 58 is in the partial masking position. As shown in FIG. 5, when the "P" format mask opening 60 in the single-piece disk 46 is in the partial masking position over the front viewfinder opening 68 in the front cover part 14, the lens opening 66 in the single-piece disk is over the lens opening 70 in the front cover part. Thus, the taking lens 26 is uncovered when the "P" format mask opening 60 is in the partial masking position. As shown in FIG. 6, when every one of the mask openings 56, 58 and 60 in the single-piece disk 46 are in respective non-masking positions not over the front viewfinder opening 68 in the front cover part 14, the lens openings 62, 64 and 66 in the single-piece disk are not over the lens opening 70 in the front cover part. Thus, the single-piece disk 46 completely masks the front viewfinder opening 68 in the front cover part 14 and the lens opening 70 in the front cover part.
As shown in FIGS. 1 and 2, the single-piece disk 46 has four evenly spaced detents or protuberances 72, 74, 76 and 78 for individually being received in a mating cavity 80 in the front cover part 14 to secure the single-piece disk in place. In FIG. 3, the detent 72 is received in the mating cavity 80. In FIG. 4, the detent 74 is received in the mating cavity 80. In FIG. 5, the detent 76 is received in the mating cavity 80. In FIG. 6, the detent 78 is received in the mating cavity 80.
Respective sets of ambient light receiving holes 82, 84 and 86, 88 and 90, and 92 and 94 are formed in the single-piece disk 46, the front cover part 14 and the main body part 12 which permit any one of three different binary encodements to be provided on the filmstrip 24 for each exposed frame. The two sets of holes 88 and 90 in the front cover part 14 and 92 and 94 in the main body part 12 are permanently aligned. The binary encodements to be provided on the filmstrip 24 are "1,1" for a "C" format selection, "0,0" for an "H" format selection and "0,1" for a "P" format selection. In FIG. 3, the holes 82 and 84 in the single-piece disk 46 are over the respective holes 88 and 90 to effect the "1,1" binary encodement. In FIG. 4, none of the holes 82, 84 or 86 in the single-piece disk 46 are over the respective holes 88 and 90 to effect the "0,0" binary encodement. In FIG. 5, the hole 86 in the single-piece disk 46 is over the hole 90 to effect the "0,1" binary encodement.
As shown in FIGS. 7 and 8, the single-piece disk 46 has four evenly spaced switch actuators 96, 98, 100 and 102 for individually closing a normally open flash switch 104 to initiate charging the flash capacitor (not shown) when the single-piece disk is rotated. Successive ones of the switch actuators 96, 98, 100 and 102 close the flash switch 104 as the single-piece disk 46 is rotated out of its respective rotational positions in FIGS. 3, 4, 5 and 6.
The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.
PARTS LIST
10. one-time-use camera
12. main body part
14. front cover part
16. cartridge receiving chamber
18. unexposed film roll chamber
20. film cartridge
22. backframe opening
24. filmstrip
26. taking lens
28. viewfinder
30. front viewfinder lens
32. rear viewfinder lens
34. shutter release button
36. thumbwheel
38. electronic flash
40. flash circuit board
42. flash emission lens
44. flash battery
46. single-piece disk
48. axial pin
50. pin-hole
52. pin-hole
54. pin hole
56. mask opening
58. mask opening
60. mask opening
62. lens opening
64. lens opening
66. lens opening
68. front viewfinder opening
70. lens opening
72. detent
74. detent
76. detent
78. detent
80. cavity
82. light-receiving hole
84. light-receiving hole
86. light-receiving hole
88. light-receiving hole
90. light-receiving hole
92. light-receiving hole
94. light-receiving hole
96. switch actuator
98. switch actuator
100. switch actuator
102. switch actuator
104. flash switch
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A camera including a viewfinder for viewing a subject to be photographed, a masking a device for the viewfinder having a number of different format mask configurations, a taking lens for forming an image of the subject, and a lens cover for the taking lens, is characterized in that the masking device and said lens cover are supported to be moved at the same time for any one of the mask configurations to be in a masking position partially masking the viewfinder when the lens cover is not covering the taking lens and for every one of the mask configurations to be respective non-masking positions not partially masking the viewfinder when the lens cover covers the taking lens.
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RELATED APPLICATIONS
Instant application is a continuation of Ser. No. 07/286,801 filed Dec. 20, 1988, now abandoned; which was a continuation-in-part of Ser. No. 07/080,865 filed Aug. 3, 1987, now U.S. Pat. No. 4,819,146.
Instant application is also a continuation-in-part of Ser. No. 07/346,321 filed May 1, 1989; which is a continuation of Ser. No. 06/686,275 filed Dec. 26, 1984, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to series-resonance-loaded inverters, particularly as used for powering gas discharge lamps.
2. Description of Prior Art
In an inverter where a gas discharge lamp load is parallel-connected across the tank capacitor of a high-Q LC circuit that is resonantly series-excited by a high-frequency voltage output of the inverter, it is necessary to provide some means to protect against the high currents and voltages resulting due to so-called Q-multiplication whenever the lamp load is removed or otherwise fails to constitute a proper load for the LC circuit.
In U.S. Pat. No. 4,370,600 to Zansky, circuit protection is provided by way of providing to the LC circuit an alternative load in the form of a voltage-clamping means; which voltage-clamping means acts to load the LC circuit during any period when the lamp does not constitute a proper load therefor.
The voltage-clamping is accomplished by rectifying the Q-multiplied voltage output of the LC circuit and by applying the resulting DC output to the inverter's DC power source.
However, during any period when voltage-clamping does occur, a relatively large amount of power circulates within the electronic ballast means: from the inverter's output, through the LC circuit, and back into the inverter's DC power source by way of the voltage-clamping means.
SUMMARY OF THE INVENTION
Objects of the Invention
An object of the present invention is that of providing control means in a series-resonance-loaded inverter.
This as well as other objects, features and advantages of the present invention will become apparent from the following description and claims.
Brief Description
A half-bridge inverter powered from a DC voltage source has a series-tuned high-Q LC circuit connected across its output. A lamp load is normally connected across the tank capacitor of the LC circuit. However, when a load is not so connected, the magnitude of the high-frequency current flowing through the LC circuit would tend to increase to destructively high levels. To prevent this from taking place, the 30 kHz high frequency current is controlled by making the inverter skip a charging-cycle each time the peak magnitude of this 30 kHz current exceeds a pre-determined level.
In particular, during normally loaded operation, the LC circuit receives a charge from the DC voltage source for each individual half-cycle of the inverter's oscillation. However, if--during a given inverter half-cycle--the magnitude of the high frequency current were to exceed a predetermined level, a control circuit would act to prevent the inverter from completing its immediately following half-cycle. As a result, with an unloaded series-tuned LC circuit connected across the inverter's output, each time the inverter acts to charge the LC circuit during a given half-cycle, the magnitude of the high frequency current increases: eventually beyond the predetermined level. After that point, the inverter will be prevented from re-charging the LC circuit until the magnitude of the high frequency current has decayed below the predetermined level; which decay will be exponential and will typically take 10-30 cycles of free-running oscillations of the high-Q LC circuit.
When the LC circuit is free-running, its current flows back and forth to the DC voltage source by way of one of the inverter's two switching transistors.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 provides a basic electrical circuit diagram of the preferred embodiment of the invention.
FIG. 2 illustrates waveshapes of various high frequency voltages and currents present within the circuit during different modes of operation where the inverter is not controlled such as to skip cycles.
FIG. 3 illustrates waveshapes of various high frequency voltages and currents present within the circuit during a mode of operation where the inverter is indeed controlled such as to skip cycles.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Details of Construction
FIG. 1 schematically illustrates the electrical circuit arrangement of the preferred embodiment of the present invention.
In FIG. 1a, a source S of ordinary 120 Volt/60 Hz power line voltage is applied to power input terminals PITa and PITb; which terminals, in turn, are connected with a bridge rectifier BR. The DC output from bridge rectifier BR is applied to a B+ bus and a B- bus, with the B+ bus being of positive polarity.
A first filter capacitor FCa is connected between the B+ bus and a junction Jc; and a second filter capacitor FCb is connected between junction Jc and the B- bus.
A first switching transistor Qa is connected with its collector to the B+bus and with its emitter to a junction Jq; a second switching transistor Qb is connected with its collector to junction Jq and with its emitter to the B- bus.
A saturable current transformer SCTa has a secondary winding SCT as connected between base and emitter of transistor Qa.
A first inverter control means ICM1, which is illustrated in detail in FIG. 1b, has a pair of transistor drive terminals TDT1 and TDT2, a pair of control input terminals CIT1 and CIT2, and a pair of feedback input terminals FIT1 and FIT2.
Terminal TDT1 is connected with the base of transistor Qb; terminal TDT2 is connected with the B- bus; terminal FIT1 is connected with junction Jq; and terminal FIT2 is connected with a junction Jx by way of primary winding SCTap of saturable current transformer SCTa.
A second inverter control means ICM2, which is illustrated in detail in FIG. 1c, has a pair of base control terminals BC 1 and BC 2, a pair of drive input terminals DIT1 and DIT2.
Terminal BCT1 is connected with the base of transistor Qb; terminal BCT2 is connected with the B- bus; terminal DIT1 is connected with a junction Jy; and terminal DIT2 is connected with a junction Jz.
A tank inductor L is connected between junctions Jx and Jy; and a tank capacitor C is connected between junctions Jz and Jc. Power output terminals POT1 and POT2 are connected, respectively, with junctions Jc and Jy. A fluorescent lamp FL is connected between power output terminals POT1 and POT2.
A resistor Rt is connected between the B+ bus and a junction Jt; a capacitor Ct is connected between junction Jt and the B- bus; and a Diac Dt is connected between junction Jt and the base of transistor Qb.
In FIG. 1b, a saturable current transformer SCTb is positioned in the gap of gapped magnetic core GMC, which is part of a cross-magnetizing electro-magnet CMEM. A magnetizing winding MW wound around core GMC is connected between terminals CIT1 and CIT2. A primary winding SCTbp of saturable current transformer SCTb is connected between terminals FIT1 and FIT2; and a secondary winding SCTbs of saturable current transformer SCTb is connected between terminals TDT1 and TDT2.
In FIG. 1c, a control transistor Qc is connected with its collector to terminal BCT1 and with its emitter to terminal BCT2; which is also connected with a C- bus. A resistor R1 is connected between the base and emitter of transistor Qc; and a diode D1 is connected with its cathode to the base of transistor Qc. An energy-storing capacitor ESC is connected between the B- bus and a B+ bus.
A transistor Qd is connected with its emitter to the C- bus. The collector of transistor Qd is connected to the C+ bus by way of a resistor R2. A resistor R3 is connected between the collector of transistor Qd and the anode of diode D1.
A transistor Qe is connected with its emitter to the C- bus. The collector of transistor Qe is connected with the C+ bus by way of a resistor R4. A resistor R5 is connected between the collector of transistor Qe and the base of transistor Qd; and a resistor R6 is connected between the collector of transistor Qd and the base of transistor Qe.
A non-saturable current transformer NSCT has a primary winding NSCTp and a secondary winding NSCTs. A saturable current transformer SCT has a primary winding SCTp and a secondary winding SCTs.
Primary windings NSCTp and SCTp are series-connected between terminals DIT1 and DIT2.
Secondary winding NSCTs is connected between the C- bus and the anode of a diode D2. The cathode or diode D2 is connected with the C+ bus. A diode D3 is connected with its anode to the anode of diode D2 and with its cathode to the cathode of a Zener diode ZD. The anode of Zener diode ZD is connected with the base of transistor Qe. A resistor R7 is connected across secondary winding NSCTs.
Secondary winding SCTs is connected between the C- bus and the anode of a diode D4, whose cathode is connected with the base of transistor Qd. A resistor R8 is connected across secondary winding SCTs.
Details of Operation
Except for effects associated with cross-magnetizing the ferrite core of saturable current transformer SCTb, the operation of the half-bridge inverter of FIG. 1 is conventional and is explained in conjunction with FIG. 8 of U.S. Pat. No. Re. 31,758 to Nilssen. That is, when not cross-magnetized, saturable current transformer SCTb is of characteristics identical to those of saturable current transformer SCTa.
For a given magnitude of the DC supply voltage, due to the effect of the high-Q LC circuit, the magnitude of the current provided to the fluorescent lamp load (or to any other load presented to the output) is a sensitive function of the waveshape of the inverter's output voltage; which output voltage is a squarewave voltage of controllable symmetry and with peak-to-peak magnitude about equal to that of the instantaneous magnitude of the DC voltage present between the B- bus and the B+ bus.
The symmetry of the inverter's squarewave output voltage is a sensitive function of the symmetry of the saturation characteristics of saturable current transformers SCTa and SCTb. In particular, the duration of the ON-time of each switching transistor is determined by the saturation characteristics of its associated saturable current transformer.
By cross-magnetizing the ferrite core of saturable current transformer SCTb, its saturation characteristics are significantly affected, thereby significantly affecting the duration of the ON-time of transistor Qb. That is, the higher the degree of cross-magnetization of SCTb, the lower the saturation flux density of its ferrite core, and the shorter the resulting ON-time of transistor Qb.
The fundamental frequency of the inverter's output voltage is essentially determined by the duration of the ON-time of the transistor that has the longest ON-time. Thus, for the circuit arrangement of FIG. 1, as long as the saturation flux of the ferrite core of saturable current transformer SCTa remains unaffected, the inverter's oscillation frequency stays approximately constant even as the saturation flux of the ferrite core of saturable current transformer SCTb is reduced. As an overall result, as the duration of the ON-time of transistor Qb is reduced, the fundamental frequency as well as the peak-to-peak magnitude of the inverter's squarewave output voltage remain approximately constant, but the symmetry of this squarewave output voltage is modified such as to reduce the magnitude of the fundamental frequency component thereof.
In fact, by sufficiently cross-magnetizing the ferrite core of saturable current transformer SCTb, the duration of the ON-time of transistor Qb may be reduced to near zero (and even actually to zero), thereby resulting in a dramatic reduction of the magnitude of the fundamental frequency component of the inverter's squarewave output voltage.
The situation is illustrated by FIG. 2, which shows the waveforms of the inverter's output voltage Vo (i.e., the voltage provided between junctions Jc and Jx; i.e., across the LC series-circuit) and the inverter's output current Io (i.e., the current flowing through the LC series-circuit). FIG. 2a depicts the waveforms under a condition when no cross-magnetization is applied to saturable current transformer SCTb; FIG. 2b depicts the waveforms under a condition when an intermediate degree of cross-magnetization is applied to saturable current transformer SCTb; and FIG. 2c depicts the waveforms under a condition when a relatively high degree of cross-magnetization is applied to saturable current transformer SCTb. (With still a higher degree of cross-magnetization applied to saturable current transformer SCTb, the inverter simply ceases to oscillate.)
Thus, with respect to the circuit arrangement of FIG. 1 and in view of the waveforms of FIG. 2, the action of inverter control means ICM1 is such that: i) the higher the magnitude of any (unidirectional) control current provided to terminals CIT1 and CIT2 of inverter control means ICM1, ii) the more cross-magnetization there be of the ferrite magnetic core of saturable current transformer SCTb, iii) the more reduction there be in the saturation flux density of this current transformers' ferrite magnetic core, iv) the shorter be the duration of the ON-time of transistor Qb, v) the lower be the magnitude of the fundamental frequency component of the inverter's output voltage, and vi) due to the frequency-discrimination characteristics of the tuned LC output circuit, the lower be the magnitude of the current provided to the load.
Now, for purposes of explaining the operation of inverter control means ICM2, it is assumed that no cross-magnetization is applied to saturable current transformer SCTb while at the same time having the fluorescent lamp non-connected. Under this condition of no loading on the LC circuit and maximum magnitude of the fundamental frequency component of the inverter's output squarewave voltage, the waveforms and magnitudes of various resulting voltages and currents are illustrated by FIG. 3.
FIG. 3a, which is for time-reference purposes only, depicts the inverter output voltage Vo as it is observed at junction Jx--with reference to the B- bus--when the inverter oscillates without being affected by either inverter control means ICM1 or inverter control means ICM2.
FIG. 3b depicts the inverter output voltage Vo under a condition where the inverter is affected by inverter control means ICM2, but not by inverter control means ICM1. More particularly, the waveform of FIG. 3a indicates that the inverter is barred from operation--by way of preventing transistor Qb from operation--by inverter control means ICM2, except for a single cycle from time to time.
FIG. 3c depicts the current Ic flowing through tank capacitor C under the condition depicted in FIG. 3b.
FIG. 3d depicts the waveform of FIG. 3c but with a different time scale.
The current of FIG. 3c, by flowing through the primary windings of transformer SCT, affects inverter control means ICM2 such as to set the flip-flop represented by transistors Qd and Qe (thereby to cause transistor Qc to become conductive and therefore to prevent transistor Qb from switching into its ON-state) each time the positive magnitude of the current exceeds a pre-set limit (identified as PSL in FIG. 3c); which pre-set limit is mainly established by Zener diode ZD. Thus, each time after the positive magnitude of the current flowing through the LC series-circuit has exceeded this pre-set limit, transistor Qb is prevented from switching into its ON-state; which, in turn, means that no additional energy will be applied to the tuned LC series-circuit after the magnitude of the current flowing through its has exceeded this pre-set level.
The current of FIG. 3c, by also flowing through the primary winding of saturable current transformer SCT, acts to re-set the flip-flop at the very beginning of each positive half-cycle of current Ic; which re-set--by way of saturable current transformer SCT and its output to the base of transistor Qd via diode D4--is accomplished before the positive magnitude of the current has had a chance to exceed the pre-set limit.
Thus, at the beginning of each positive half-cycle, the flip-flop is re-set, thereby making transistor Qc non-conductive and transistor Qb ready to enter its ON-state. Then, except if the magnitude of the current during this positive half-cycle were to exceed the pre-set limit, transistor Qb would enter its ON-state during the next-following negative half-cycle.
In FIG. 3c, the area of each positive half-cycle that exceeds the pre-set magnitude limit is cross-hatched. Similarly, the initial part of each positive half-cycle, during which the re-setting of the flip-flop occurs, is cross-hatched.
As an overall result, the inverter of FIG. 1 operates in the following manner.
Absent cross-magnetization of the ferrite core of saturable current transformer SCTb, current flowing through the LC circuit will act to provide base drive for both switching transistors (Qa/Qb); and, as a result of positive feedback, an inverter squarewave output voltage like that depicted in FIG. 3a will be generated. Without fluorescent lamp FL connected at the inverter's output, after but a few initial cycles, the magnitude of the positive current flowing through the LC circuit will grow to a point exceeding the pre-set limit; whereafter the base drive for transistor Qb will be shunted away by transistor Qc, thereby rendering transistor Qb inoperable by preventing it from entering its ON-state. Even without transistor Qb in operation, however, the energy stored in the LC circuit will keep on oscillating: the current flowing back and forth through transistor Qa and capacitor FCa. However, since there are losses associated with this oscillation, the magnitude of the oscillating current will gradually decrease (see FIG. 3c): eventually to a point where the magnitude of the positive half-cycle will fail to exceed the pre-set limit, thereby not preventing transistor Qb from entering its ON-state when its next opportunity arrives; which next opportunity arrives with the immediately following negative half-cycle.
Thus, during this immediately following negative half-cycle, transistor Qb does enter its ON-state--as indicated in FIG. 3b --and the LC circuit thereby receives a charge of energy, thereby causing the magnitude of that negative half-cycle to increase (rather than decrease); whereafter the magnitude of the next following positive half-cycle will be large enough to exceed the pre-set limit; etc.
FIG. 3d shows the waveform of the resulting amplitude-modulated current Ic. Since the inverter frequency remains approximately constant, the magnitude of Ic (the current flowing through the tank capacitor) is proportional to the magnitude of the voltage present across the tank capacitor; which means that the waveform of FIG. 3d also represents the waveform of the output voltage provided between terminals POT1 and POT2.
Additional Comments
a) Detailed information relative to a fluorescent lamp ballast wherein the fluorescent lamp is powered by way of a series-excited parallel-loaded L-C resonant circuit is provided in U.S. Pat. No. 4,554,487 to Nilssen.
b) The instantaneous peak-to-peak magnitude of the more-or-less squarewave output voltage provided by the half-bridge inverter between junctions Jq and Jc is substantially equal to the instantaneous magnitude of the DC supply voltage.
c) Current transformers SCTa, SCTb, NSCT and SCT require only a miniscule amount of voltage across their primary windings. Hence, the magnitude of the voltage-drops between junctions Jq & Jx and between junctions Jy & Jz are substantially negligible, and the inverter's full output voltage is therefore effectively provided across the LC circuit, which consists of tank capacitor C and tank inductor L.
d) The circuit arrangement of FIG. 1 provides for two separate and substantially independent means for controlling the effective magnitude of the inverter's more-or-less squarewave output voltage.
As indicated in FIG. 2, inverter control means ICM1 provides for gradual control of the symmetry of the inverter's more-or-less squarewave output voltage, thereby providing corresponding control of the magnitude of the fundamental frequency component of this output voltage; which, in turn, provides for gradual control of the power provided to the tuned LC circuit and therefore to the load connected therewith by way of terminals POT1 and POT2. In case of a lamp load, by controlling the magnitude of current provided to terminals CIT1 and CIT2 of inverter control means ICM1, effective control of light output is attained. However, in the absence of a load on the LC circuit, it is difficult to control the effective magnitude of the inverter's output voltage to a point low enough to avoid the development of excessive currents though the LC circuit: it is simply too difficult with currently available bipolar switching transistors to make the duration of the ON-time associated with transistor Qb as low as then required.
As indicated in FIG. 3, inverter control means ICM2 provides for automatic control operative to prevent the development of excessive currents through the LC circuit.
Thus, in effect, control means ICM1 is operative to control the amount of charge provided to the LC circuit per charging cycle; whereas control means ICM2 is operative to control the repetition rate of the charging cycles.
e) Controlling the inverter's output by way of controlling the symmetry of its squarewave output voltage has an advantage compared with controlling its output by way of controlling the inverter's frequency.
The inverter's frequency can be controlled by cross-magnetizing the ferrite cores of both saturable current transformers. However, as frequency increases, the resulting output current will become more-and-more out of phase with the inverter's output voltage; which implies that each transistor will switch at a point where the magnitude of the forward-flowing current is relatively large; which, in turn, leads to high switching losses.
On the other hand, by cross-magnetizing only one of the ferrite cores, transistor switching occurs at a more favorable point--particularly in the situation of minimum power output.
f) With reference to FIG. 3d, one full charging cycle causes the magnitude of Ic to increase by a substantial amount; whereafter a relatively large number of free oscillations occur before the magnitude falls below the pre-set limit and a new charging cycle is initiated. As a result, the amplitude modulations on the Ic current--and thereby on the output voltage--get to be relatively large.
By providing only a partial charge per charging cycle--such as would result by providing an amount of control current to terminals CIT1 and CIT2 of control means ICM1--the increase in the magnitude of Ic resulting from a single charging cycle would be reduced; and, as a result, the degree of amplitude modulation would be correspondingly reduced.
g) As may be noticed in FIG. 2, transistor Qa ceases to conduct in its forward direction while current is still flowing in the forward direction. After transistor Qa has ceased to conduct, the forward-flowing current will continue to flow for a brief period. However, instead of flowing through capacitor FCa and the B+ bus, it will now flow through capacitor FCb and the B- bus, through the secondary winding of saturable current transformer SCTb, and through the base-collector junction of transistor Qb.
h) In some situations it may be advantageous to place a commutating rectifier in parallel with each switching transistor, especially with transistor Qb. In particular, a commutating rectifier may be connected with its anode to the emitter and with its cathode to the collector of each of transistors Qa and Qb.
i) The waveform of FIG. 3b is idealistic. In reality, with most commonly available components, the waveform will have very narrow negative-going spikes occurring between each major negative-going pulse--with one such narrow spike occurring just prior to each time the current waveform of FIG. 3c crosses the zero-line from positive to negative.
j) Forward conduction of a transistor is defined as current flowing, with the aid of forward base drive current, directly between the collector and the emitter; which, in case of transistor Qa for, instance, means that forward current is defined as positive current flowing from its collector to its emitter while positive drive current is being provided to its base.
k) It is noted that fluorescent lamp FL could have been connected between junctions Jc and Jz instead of between junctions Jc and Jy.
l) In inverter control means ICM2, saturable current transformer SCT may be eliminated by using a so-called one-shot instead of the indicated ordinary flip-flop. That is, the flip-flop may be so arranged as to automatically reset itself after a pre-determined period of time (ex: about 30 micro-seconds) instead of using the pulse from saturable current transformer SCT to effect such resetting.
m) It is believed that the present invention and its several attendant advantages and features will be understood from the preceeding description. However, without departing from the spirit of the invention, changes may be made in its form and in the construction and interrelationships of its component parts, the form herein presented merely representing the presently preferred embodiment.
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A half-bridge inverter is powered from a DC voltage source and has a series-tuned high-Q LC circuit connected across its output. A load is normally connected across the tank capacitor of the LC circuit. When a load is not so connected, the magnitude of the high-frequency current flowing through the LC circuit would tend to increase to destructively high levels. To prevent this from taking place, the high frequency current is controlled by making the inverter skip a charging-cycle each time the peak magnitude of this current exceeds a pre-determined level. In particular, during normally loaded operation, the LC circuit receives a charge from the DC voltage source for each individual half-cycle of the inverter's oscillation. However, if--during a given inverter half-cycle--the magnitude of the high frequency current exceeds a predetermined level, a control circuit acts to prevent the inverter from completing its immediately following half-cycle. As a result, with an unloaded series-tuned LC circuit connected across the inverter's output, each time the inverter acts to charge the LC circuit during a given half-cycle, the magnitude of the high frequency current increases beyond the predetermined level. Thereafter, the inverter will be prevented from re-charging the LC circuit until the magnitude of the high frequency current has decayed below the predetermined level; which will typically take about 30 cycles of free-running oscillations of the LC circuit.
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FIELD OF THE INVENTION
The invention relates to a device for selectively separating particles in a liquid, in particular in a suspension. The invention is particularly suitable for the paper industry, in particular the cleaning of particulate suspensions, for example fibrous suspensions. The invention may, however, find other applications in separation or centrifugal fractioning techniques, in the recovery of immiscible liquids of differing densities, etc.
BACKGROUND OF THE INVENTION
There currently exists in the paper industry a large number of apparatuses intended for the cleaning or separation of fibrous suspensions.
In the document EP-B-0,037,347 of the Applicant (corresponding to U.S. Pat. No. 4,443,331), a free vortex device has been proposed, in which the suspension to be cleaned is supplied to a chamber of revolution rotating about its axis, of the type comprising:
fixed means for supplying the suspension, arranged along the longitudinal axis of said chamber of revolution, extended by movable means for deviating the suspension current towards the periphery of the chamber;
means for driving said chamber in rotation about its longitudinal axis;
fixed means for discharging the cleaned suspension and various separated fractions, arranged along the longitudinal axis of said chamber, preceded by movable deviating means and in which the means for discharging the lightest components is arranged along the longitudinal axis of rotation (2) on the same side as the supply means,
wherein:
the movable deviating means preceding the fixed outlet means intercept most of the throughput of the suspension in the region of the periphery of the chamber, then deviate it towards the longitudinal axis of rotation, so as to recover most of the kinetic energy of rotation;
and wherein the main outlet means are situated at the opposite end to that of the chamber comprising the supply means and are arranged at the periphery of this chamber, so that a large central centrifugal zone is available.
This device provides excellent results as regards efficiency, reject rate and energy consumption, in particular for outputs less than about three hundred cubic meters per hour of diluted pulp (concentration of the order of 1%). In order to treat effectively higher outputs, i.e. throughputs greater than 300 cubic meters per hour of diluted pulp, it becomes necessary to increase the volume of the apparatus and hence its diameter. These large apparatus with a high cleaning capacity thus have various drawbacks depending on the conditions of their use.
Thus, if diluted pulp is being treated, there is first of all an increase in the pressure drop in the region of the bearings and the inlet/outlet ends, as well as in the peripheral cleaning zone, on account of the need to maintain sufficient turbulence with a high throughput. Furthermore, again in the case of diluted pulp, it becomes necessary, on account of the larger diameter, to increase the counterpressure at the outlet in order to extract the rejects intercepted along the axis of the central zone of the vortex, or alternatively to intercept it at the periphery of this zone: there is thus formed along the axis of the apparatus an air core which, having no fixed geometry, moves inside the suspension and generates vibrations throughout the body of the apparatus.
If treating pulp with a higher concentration (up to about (3)% (sic), the problems which arise are different. First of all, owing to the centrifugal force effect, the pulp tends to accumulate against the walls, thus also resulting in the risks of vibrations due to imbalances and clogging of the apparatus by very concentrated pulp. Furthermore, in order to individualize the movement of the fibers, it is necessary to maintain a high degree of turbulence and, for this reason, a big difference in peripheral/wall flow speeds, thus resulting in high pressure losses. Moreover, control of the flow at the periphery of the vortex, by the geometry of the ends, and that of the body of the apparatus essentially for small diameters, is fairly delicate and poses problems as regards homogeneity of flow, which may adversely affect the quality of cleaning and which result in the risk of deposits.
SUMMARY OF THE INVENTION
The present invention overcomes these drawbacks.
It relates to an improved device of the same type as that described in the document EP-B-0,037,347, in which control of the flow in the peripheral cleaning zone is improved and evacuation of the light reject in the central zone of the vortex is promoted, even in the case of high throughputs, while ensuring stable operation of the apparatus.
The subject of the invention is also an improved device of the type in question enabling large quantities of pulps of the order of five hundred meters cubed per hour (500 m 3 /h) and more to be cleaned.
This improved device for separating particles in a liquid, in which the suspension to be cleaned is supplied to a chamber of revolution rotating about a longitudinal axis, of the type comprising:
fixed means for supplying the suspension, arranged along the longitudinal axis of the chamber of revolution, extended by movable means for deviating the suspension current towards the periphery of the chamber;
means for driving said chamber in rotation about its longitudinal axis;
fixed means for discharging the cleaned suspension and the different separated fractions, arranged along the longitudinal axis of said chamber, preceded by movable deviating means and in which the means for discharging the lightest components is arranged on the longitudinal axis of rotation, either on the side where the suspension to be cleaned is admitted or on the side where the cleaned suspension is discharged, and in which:
the movable deviating means preceding the fixed outlet means intercept most of the throughput of the suspension in the region of the periphery of the chamber, then deviate it towards the longitudinal axis of rotation so as to recover most of the kinetic energy of rotation;
the outlet means are situated at the opposite end to that of the chamber comprising the supply means and are arranged at the periphery of this chamber;
wherein moreover a central body of revolution is arranged inside this chamber along the longitudinal axis of rotation of the chamber, between the means supplying the suspension and the means discharging the cleaned suspension, the said central body of revolution:
having a general convergent shape from the inlet means towards the outlet means;
and comprising a run-off means arranged in the vicinity of the smallest cross-section of said central body of revolution, connected to an axial outlet duct.
In other words, the invention consists in providing in the device described in the document EP-B-0,037,347 of the Applicant, a single rigid central body with a general tapered and convergent shape inside the chamber, which occupies the decreasing part of the gap between the supply and outlet means, associated with a run-off means arranged in the vicinity of its smallest cross-section and intended to extract the light fraction of the suspension.
The run-off system provided in the central body of revolution of the apparatus converts the residual energy of the vortex (dynamic and static pressures) into static pressure. This avoids the counterpressure on the outlet side and therefore enables the inlet pressure to be correspondingly reduced, resulting in an appreciable saving in energy.
Advantageously:
the gap between the inner wall of the chamber and the wall of the central body increases gradually from the inlet towards the outlet;
the chamber has an inner cylindrical general shape and the characteristic central body has a diabolo shape;
the diabolo-shaped central body comprises three distinct portions, namely:
a first frustoconical portion, tapered towards the outlet;
a second cylindrical portion connected to the first portion, having at its periphery orifices associated with the run-off means;
a third portion, also frustoconical, but with a conicity which is opposite to that of the first portion, connected to the second cylindrical portion and having an axial duct associated with the run-off means and intended to extract the light fraction;
the run-off means consist of radial fins associated with the peripheral orifices of the second cylindrical portion;
the inlet and outlet ends of the central body are integral with the chamber of revolution and are driven in rotation by a single motor at the same speed as the speed of rotation of said chamber;
the central body is driven in rotation at a speed which is different from that of the chamber, but is integral with the inlet and/or outlet ends of the chamber; in this case, the central body advantageously has fins at the periphery, arranged along a generatrix.
In the sector of centrifuges, or centrifugal settlers, it has been known for a long time to arrange, inside the rotor, a central body substantially of revolution and with a shape similar to the general inner shape of the rotor. This shape defines a flow space with a substantially constant thickness so as to avoid any unfavorable agitation during the settling of the suspension. This central body generally has scraping or run-off elements for the heavy particles which have settled against the inner wall of the rotor so as to return them to the vicinity of the axis and to extract them from the apparatus (see, for example, FR-A-1,450,895 (corresponding to U.S. Pat. No. 3,467,304); U.S. Pat No. 4,332,350 or GB-A-1,366,170). On the other hand, in the device of the invention, the central body of necessity has a shape which is different from the inner wall of the chamber, in particular at the level of the run-off devices, so as to return to the vicinity of the central body, and to extract in the axis, not only the heavy particles, but also the light fraction of the suspension.
Thus, for the extraction of the light fractions, the state of the art argued against the use of a central body.
In other words, the invention consists, for this new application and in order to obtain the objective of extracting the light fraction, in defining a particular and specific shape for the central body relative to the inner wall of the chamber, namely a convergent shape, and in positioning the run-off point on this central body at the point with the smallest cross-section.
If the central body is integral with the rotating chamber of the apparatus, the apparatus is in this case particularly suitable for the sector of fine cleaning into diluted pulp, since the presence of the central body allows the flow to be channeled more effectively, in particular upon leaving the injection channels of the inlet end. In fact, the parasitic recirculation currents as well as the radial variations in angular speed of the pulp are reduced, thereby making the flow more uniform, in particular with a more homogeneous turbulent condition.
On the other hand, if the central body is driven in rotation separately from the rotating body of the apparatus, but integrally with the suspension inlet and/or outlet end(s), the apparatus is thus perfectly suited to the cleaning of more concentrated suspensions. In fact, control of the flow in the external peripheral zone is improved not only by the presence of the central body but also by the choice of its rotational speed differential, which enables the pulp to be entrained in rotation again, so that the suspension retains an optimum degree of turbulence. In practice, the rotational speed differential of the central body is chosen according to the difference in speed of the suspension relative to the wall in the region of the injection zone, depending on the characteristics of the supply end.
The chamber, the supply means, the movable deviating means, the outlet means and the rotational driving means are made in a known manner, notably in accordance with the teachings of the document EP-B-0,037,347 referred to in the preamble, for example from stainless steel.
The convergent central body has the following characteristics:
a conical (diabolo) shape converging from the suspension supply and outlet ends enables the light reject to be properly evacuated, by promoting the displacement of the light components towards the extraction zone which may be situated at any level between the ends, and in particular towards the outlet end, where the latter comprises the axial tube for evacuation of the light reject;
the diameter of the run-off, arranged at the point of the diabolo with the smallest cross-section, must be sufficiently great in order to avoid the formation of the air core and in order to recover the residual pressure necessary for the extraction of the light fraction, but it must also be substantially less than the internal diameter of the chamber in order to avoid the simultaneous extraction of heavy particles;
the diameter of the central body in the region of the supply and outlet ends must be fairly large in order to control properly the flow in the peripheral cleaning zone, and more particularly in the region of the supply end, so as to channel the parasitic currents more effectively; in the case where the central body is driven in rotation separately from the body of the apparatus, this central body may advantageously be equipped with elements for re-entrainment of the suspension, such as radial fins arranged longitudinally on its surface and more or less close to the wall according to the shearing, and hence the turbulence required.
For technical and mechanical reasons, the inner wall of the chamber is cylindrical. A slightly frustoconical general shape could, if required, be used with the proviso that, as already stated, the distance between the walls of the chamber and of the central body increases uniformly from the inlet towards the run-off device. This slightly frustoconical arrangement entails, however, an increased construction cost which is not essential.
The manner in which the invention may be achieved and the advantages arising therefrom will emerge more clearly from the examples of embodiment taken in conjunction with the attached figures.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 shows in basic schematic form, in longitudinal cross-section, an apparatus in which the characteristic central body is integral with the chamber of the apparatus.
FIG. 2 shows in schematic form, in longitudinal cross-section, an apparatus where the central body is capable of being driven in rotation separately from the chamber of the apparatus.
FIG. 3 shows in basic schematic form, in longitudinal cross-section, a preferred embodiment of the invention, whereas FIG. 4 illustrates, in cross-section, a detail of FIG. 3 (run-off) taken along the axis IV--IV'.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, the cleaning apparatus consists of:
an internally and externally cylindrical hollow chamber (1) driven in rotation about its longitudinal axis (2), by known means, not shown (motor);
bearings (3) and (4), associated with conventional seals (20-24), allowing the chamber (1) to rotate about its axis (2);
a tube (5) forming a fixed means for supplying the suspension to be cleaned and leading by means of a connection piece rotating at the end of the chamber (1) into a supply duct (6) forming a movable deviating means;
opposite the inlet means (5,6) and opposite the assembly (1), outlet means also formed by two fixed ducts (9,10) forming fixed outlet means, connected via rotating connection pieces, respectively to the duct (7) closest to the outlet periphery, for the extraction of the heaviest particles and to the concentric outlet duct (8), for the extraction of the intermediate fraction;
a diabolo-shaped rigid characteristic central body of revolution (11) aligned on the longitudinal axis (2) and fixed to the chamber (1) by sealed means (not shown); this central body (11) comprises a radial run-off or radial passage means (12) (having an inlet remote from the axis of the chamber 1) situated in the smallest cross-section of the diabolo and open to the chamber to collect the lightest fraction of the suspension closest to the axis of rotation (2); consequently, the distance D (FIG. 3) between the inner cylindrical wall of the chamber (1) and the wall (51) of the diabolo (11,30) increases uniformly from the inlet (5,6) towards the outlet (7,8);
an outlet duct (13) for the cleaned suspension, open to the radial inner end of the run-off (12) and along the longitudinal axis (2) of the chamber (1), for eliminating the lightest fraction of the suspension collected by the run-off (12).
This therefore constitutes an improved cleaner of the type described in the aforementioned document EP-B-0,037,347, having a cylindrical chamber (1) in which is arranged a diabolo-shaped single central body (11) with a run-off (12) in the smallest cross-section, which promotes the removal of light reject, reduces the pressures necessary for effective operation of the cleaner, avoids vibration problems and improves the homogeneity of the suspension.
On the device of FIG. 2 the central body (11) and the inlet (6) and outlet (7) means form an integral unit driven in rotation separately from the chamber. As in FIG. 1, the fixed means (5) and (8) are connected to the movable means (6) and (10) respectively by sealed connections (20-24) and the central body has a diabolo shape that, two oppositely directed cones joined at their smallest diameter ends. This diabolo (11) is also equipped at the periphery with fins (14,15) for entraining the suspension to be cleaned, arranged along generatrices and equidistant from each other. Bearings (16,17) associated with conventional seals (23,24), allow the central diabolo (11) to rotate about the longitudinal axis (2) at an appropriate speed. The run-off (12) provided in the central body forms a movable means for discharging the light fraction and is extended downstream by an evacuation duct (13) arranged along the axis (2). A radial run-off or radial passage means (18) provided in the outlet end (19) allows extraction of the heaviest fraction in the peripheral zone (7), forming the movable means for discharging this heavy fraction. This run-off (18) is extended downstream by an outlet duct (25) arranged along the longitudinal axis (2). Movable means (26) for supplying an auxiliary dilution fluid are provided along the outlet end (19) integral with the central diabolo (11) and are connected via sealed connections (22) to fixed means (27) for supplying the auxiliary dilution fluid. It is important that the characteristic run-off (12) be arranged in the vicinity of the smallest cross-section of the central convergent body (11) and preferably on this point, an inlet radially remote from the axis of the chamber 1, in order to satisfactorily recover the entire light fraction.
The introduction of washing water minimizes, in the case of paper pulps, the losses of fibers which tend to concentrate in the region of the wall with the heavy contaminants.
In the advantageous embodiment of the device of FIG. 2, the unit (18,25) for continuous evacuation of the heavy fraction is associated with devices (26,27) for continuous ejection of washing water which use the space (26) situated between the outlet end (19) linked to the diabolo-shaped central body (11) and the outlet flange of the chamber (1) of the apparatus. In a simplified embodiment, the same devices (18,25) may be used alternately for the discontinuous injection of water for washing the heavy fraction and for discontinuous extraction of the heavy contaminants, the extraction phase being advantageously very short compared to the washing phase, in order to minimize the heavy-fraction losses.
FIG. 3 shows in schematic form and in longitudinal cross-section a device particularly suited to the cleaning of paper suspensions. The inner wall of the chamber (1) is cylindrical. The characteristic diabolo-shaped convergent central body (11) comprises:
a first frustoconical portion (30), tapered towards the outlet (7), occupying more than half the distance between the inlet (6) and the outlet (7); for ease of manufacture and mounting, this frustoconical portion (30) is fixed at its wide part (31) to the feed end (32) with a cylindrical shape and having the oblique channels for injection of the paper pulp; the distance D between the inner wall (50) of the chamber (1) and the wall (51) of the central body (30) thus increases uniformly from the inlet (6) towards the outlet (7);
a second cylindrical portion (33) shrunk (34) onto the tapered end of the first portion (30), in order to define a zone with a smaller cross-section and having at the periphery thereof orifices (35,36,37) and the inner wall (38) of which (see FIG. 4) has radial fins (40,41,42); the orifice (35-37) and fin (40-42) unit forms a run-off unit or radial passage means similar to (12); consequently, as previously (12), the run-off takes place at the low point of the central body (30);
a third frustoconical portion (45), but with a conicity which is opposite to, (30) integral at (46) with the cylindrical portion (33) and which has an axial duct (47) similar to (13), associated with the run-off unit (35-37, 40-42) and intended to extract the light fraction from the suspension.
In a practical embodiment, the cylindrical chamber (1) has an internal diameter of 0.75 m for a length of 2.5 m. The cylindrical inlet portion (32) has a diameter of 0.62 m for a length of 0.2 m. The first frustoconical inlet portion (30) has a length of 1.7 m for a diameter which decreases gradually from 0.6 to 0.36 m. The cylindrical run-off section (33) has a length of 0.2 m for a diameter of 0.36 m. The third frustoconical outlet portion (45) has a length of 0.4 m with a diameter which increases from 0.45 to 0.55 m. Finally, the orifices (35,36) have a diameter of 0.05 m and the axial duct (47) has a diameter of 0.05 m.
Such a cleaner device according to FIGS. 3 and 4 is able to handle throughputs of the order of five hundred cubic meters per hour and more. In the case where the suspension treated is a paper pulp suspension, the fiber consistency of which is of the order of 0 to 3%, and preferably of the order of 1.5%, the efficiency of this cleaner is comprised between 90 and 99%, with a fiber loss rate of less than 0.5%. Moreover, the energy consumption is considerably smaller compared to that of a plant comprising two conventional cleaners in parallel (21 kw compared to 2×17 kw), a saving to which a saving in pumping energy of 12 kw must be added, i.e. a total of 21 kw compared to 46 kw for a nominal throughput of 450 m 3 /hour. This considerable reduction is due to the increase in the capacity of the apparatus and to the fact that it is no longer necessary to provide a counterpressure at the outlet of the apparatus.
Furthermore, because of the presence of the central body of revolution, in particular in a diabolo shape, which prevents the formation of the air core and because of the general symmetry of the device in rotation, the detrimental vibrations are eliminated.
The separating device of the invention has numerous advantages compared to those known hitherto, in particular that described in the document EP-B-0,037,347 of the Applicant mentioned in the preamble. There may be mentioned:
the possibility of increasing the diameter of the chamber, in other words its volume, and therefore the production of treated substances and, with equivalent efficiency, the specific productivity;
for the same quantity of treated substance, the possibility of reducing the investment cost;
the reduction in the consumption of energy, by reducing the specific apparatus-driving and pumping powers, because of the reduction in the counterpressure;
the substantial reduction in detrimental vibrations, which improves the lifespan of the mechanical elements (bearings, mountings, joints . . . ).
Consequently, this device may be used successfully for the treatment and cleaning of various suspensions, such as for example suspensions of various paper pulps, waste water or polluted water, water/petroleum suspensions, etc.
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A device for separating particles in a liquid in which a paper suspension to be cleaned and supplied to a chamber of revolution (1) rotating about an axis (2). Movable deviators (7, 8) precede the fixed outlets (9, 10) to intercept most of the through-put of the suspension in the region of the periphery of the chamber (1), then deviate it towards the longitudinal axis of rotation (2) so as to recover most of the kinetic energy of rotation. The outlets (7, 8, 9, 10) are situated at the opposite end to that of chamber (1) from the supply (5, 6) and are arranged at the periphery of this chamber (1). A diabolo-shaped central body of revolution (11) is arranged inside the chamber, along the longitudinal axis of rotation (2) for rotation about its axis and with a radial run-off (12) in the vicinity of its smallest cross-section connected to an axial outlet duct (13).
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BACKGROUND OF INVENTION
In the artificial insemination of poultry, such as turkeys, for example, there may be employed very fine, hollow, cylinders which are loaded with a precise amount of semen and a separate straw is then employed for each female fowl in order to ensure application of the desired amount of semen in each artificial insemination operation. These fine, hollow cylinders are termed "straws" and reference is made to U.S. Pat. No. 3,774,578 for "Poultry Insemination Apparatus" containing description of apparatus for the utilization of such straws. Reference is also made to U.S. Patent Application Ser. No. 384,937 for "Straw Charging and Feeding Apparatus," wherein the present invention, A. G. Horsting, is a co-inventor, describing and illustrating apparatus for the loading of fine, hollow cylinders or straws with poultry semen.
The utilization of a separate sterile straw for each artificial insemination operation is highly advantageous in preventing infection or the spread of disease in poultry being operated upon. However, it will be realized that commercial artifical poultry insemination is a very large scale operation involving hundreds of thousands and even millions of fowl. The insemination straws may be formed of a variety of materials such as glass or plastic; however, with even the most inexpensive materials, the very large volume of straws required poses a problem of cost and also supply. Reuse of these straws requires an extremely thorough cleaning disinfecting and again the large number thereof involved necessitates some type of automated process for the efficienct and inexpensive handling thereof.
SUMMARY OF INVENTION
The present invention provides a fully automated system and apparatus for the thorough cleaning and disinfecting of fine cylinders or straws employed in artificial poultry insemination. The apparatus hereof also provides for the thorough drying of the cleaned and disinfected straws and the packaging of same in a magazine so that they may be directly loaded into apparatus such as disclosed in U.S. Patent Application Ser. No. 384,937 noted above, to preclude the possibility of contamination.
The apparatus of the present invention includes a hopper into which straws are dumped and which feeds straws individually in succession therefrom onto transport means which holds each straw in predetermined orientation. The transport means of the present invention moves successive straws through a cleaning and disinfecting cycle wherein the exterior of the straws are scrubbed and the interior of the straws are washed while both interior and exterior are disinfected. The transport means then continues the movement of straws through a rinsing station wherein both the interior and exterior of the straws are thoroughly rinsed. Individual straws after rinsing are then successively moved by the transport means into a drying cycle wherein the interior of each straw is thoroughly dried and the exterior of the straws are dried so that the straws are then individually in condition for further utilization. The dry, cleaned and disinfected straws are automatically loaded by the present invention into a magazine or the like, again in predetermined orientation with each other whereby the magazine may be closed and moved in such condition to straw filling apparatus without being touched by human hands.
The entire system and apparatus of the present invention is automated and the straws thereof move continuously therethrough to provide a high rate of cleaning and disinfecting so that the large numbers of straws may be processed hereby to provide the necessary volume for commercial artificial poultry insemination.
DESCRIPTION OF FIGURES
The present invention is ilustrated as to a single preferred embodiment thereof in the accompanying drawings wherein:
FIG. 1 is a central longitudinal vertical section through a preferred embodiment of the present invention, with the section being offset in the plane of the chain cylinders to illustrate chain drive;
FIG. 2 is a transverse vertical sectional view taken in the plane 2--2 of FIG. 1;
FIG. 3 is a partial sectional view taken in the plane 3--3 of FIG. 2;
FIG. 4 is a schematic flow diagram in accordance with the present invention;
FIG. 5 is a schematic plan view of the apparatus of the present invention;
FIG. 6 is a partial sectional view taken in the plane 6--6 of FIG. 3; and
FIG. 7 is an enlarged sectional view taken in the plane 7--7 of FIG. 5.
DESCRIPTION OF PREFERRED EMBODIMENT
A preferred embodiment of the present invention, as illustrated in the drawings, includes a housing 11 including a vertical back wall 12, front and rear walls 13 and 14 and an inclined bottom 16. A front wall 17 includes a lower fixed portion 17a and an upper removable portion 17b as shown, for example, in FIG. 2. At the forward end of the apparatus there is provided an inlet hopper 21 having an open top with an inclined back wall 22. At the bottom of the hopper there is provided a rotatably mounted cylinder 26 having peripherally spaced longitudinal notches 27 thereabout. The cylinder 26 extends transversely of the housing between the back and front walls and has a pair of ball chains 28 and 29 disposed thereabout adjacent opposite ends of the cylinder. The chains 28 and 29 extend about the cylinder 26 in circumferential grooves and fit into peripheral indentations 30 in the bottom of these grooves. Each of the chains is composed of a succession of balls or spheres 31 connected by links 32 and such chains may be conventional commercially available items of this type. Balls 31 of the chains and indentations 30 of the cylinder are dimensioned such that the balls fit in the indentations so that the cylinder acts in part as a cog wheel for moving the chains. These chains 28 and 29 extend longitudinally through the housing about a second peripherally indented cylinder 33 mounted for rotation at the rear end of the housing. An idler cylinder 34 is rotatably mounted on a pivotally mounted arm to adjustably tension the chains 28 and 29.
The chains 28 and 29 are driven by one of the cylinders 26 or 33 to move continuously through the housing longitudinally thereof and U-shaped chain supports 36 are provided beneath the upper traverse of the chains, as illustrated in FIG. 2, to prevent lateral movement of the chains or sagging thereof. The separation of the individual balls 31 of the chains is just sufficient to accommodate the placement of a straw 41 therebetween upon the link 32 connecting the balls. This is illustrated in FIG. 1 where it will be seen that the bottom of the hopper 21 is formed of the notched cylinder 26 so that movement of the cylinder across the otherwise open bottom of the hopper will cause successive straws from the hopper to fall into the notches 27 and be moved onto the chains 28 and 29 to then be transported individually therefrom rearwardly of the housing. The forward lower part of the hopper is preferably formed of an angled plate 42 mounted on a pivot arm 43 with the plate 42 resting upon the cylinder 26 so that rotation of the cylinder 26 with the chains thereabout will cause the pivoted plate to ride over the notched cylinder periphery and thus vibrates the straws in the hopper to overcome any tendency of same to stick together or lodge in a fixed position. This assists in feeding the straws into the cylinder notches and thence onto the transport chains whereby successive straws are moved from the hopper upon the chains.
The housing 11 is divided into a plurality of transverse compartments by successive partitions 46, 47, 48 and 49 extending transversely of the upper portion of the housing and mounted on the back wall 12. Transverse support beams 51 mount the chain guides 36. The separate transverse compartments hereof are open to the bottom of the housing which forms a sump 52 and the chains 28 and 29 pass across the bottom of these compartments immediately beneath the partitions 46 to 49.
The first cycle of the present invention following removal or transport of successive individual straws from the hopper is that of cleaning disinfecting. This is accomplished in a compartment 56 disposed between the partitions 46 and 47. Within this compartment 56 there are mounted a pair of scrub brushes 57 and 58 which may be formed with hollow shafts slidably mounted upon driven shafts 59 with a pin through the latter engaging a cutout on the brush shafts for rotating the brushes.
Provision is made for maintaining the straws at a desired height within the compartment 56 and successive compartments by mounting a strip 66 along the back wall 12 of the housing with such strip having a U-shaped projection 67 longitudinally thereof along one half of the chamber and within which one end of the straws rides. Within the U-shaped projection there are preferably provided upper and lower flexible strips 68 between which the straw ends move to grip the ends of the straws and hold them in desired vertical position as they move through the compartments. The straws are prevented from bouncing upwardly from the chains by hold-down strips 71 and 71' extending between the partitions 46 and 47 immediately above the straws 41 on the chains and spaced apart so as to engage the straws if they should attempt to rise from the chains. A central low transverse wall 72 extends across the chamber 56 between the brushes 57 and 58 and the hold-down strips 71 and 71' are engaged therewith as by extension into slots therein with strips 71 in the first part of the compartment laterally offset with respect to strips 71' in the second part in order that the brushes shall engage all of the straw exteriors as the straws pass through the compartment.
The brushes and straws in the compartment 56 are subjected to a "rain" of cleaning and disinfecting fluid fed through an apertured tube 76 disposed transversely of the chamber between and above the brushes 57 and 58. Thus the exteriors of the straws are scrubbed by the brushes in passage through the chamber 56 while the cleaning and disinfecting fluid is directed onto the brushes. The interiors of the straws are also cleaned and in this respect reference is made to FIG. 2 wherein it will be seen that each straw in passing through a first portion of the chamber 56 is disposed with one end between the resilient strips 68 of the U-shaped projection 67 on strip 66 and the other end is engaged by a retainer strip 77 extending longitudinally of the chamber 56 and engaging only the top of the straw so that the center opening thereof is left unobstructed.
The interior of the straws are washed by the passage of cleaning and disinfecting material therethrough and to this and the strip 66 is provided with a plurality of small openings 81 therethrough aligned with the centers of the straws 41 in passage through the compartment 56. Fluid is supplied to the openings 81 under pressure from a pipe 82 threaded into a boss on the back wall 12 of the housing. An opening 84 in the back wall communicates between the pipe 82 and a longitudinal recess 85 in strip 66 communicating with the small orifices 81 that are aligned with the centers of the straws so that liquid cleaner and disinfectant supplied to the pipe will be forced through the straws to exit therefrom at the far ends of the straws, as indicated by the small arrows in FIG. 2.
It will be seen that the straws are successively transported by the chains 28 and 29 through the cleaning and disinfecting compartment 56 while such straws are maintained in fixed orientation to each other. The straws are prevented from lateral motion by fitting between the bottom of the U-shaped mwmvwe 67 on a strip 66 and the retaining strip 77 in the first portion of chamber 56, while the straws are prevented from moving up and down by the hold-down strips 71 and the first ends of the straws are maintained in alignment with the orifices 81 by the resilient strips 68 in the U-shaped member 67. In the latter portion of the chamber 56 the U-shaped projection 67 is omitted and the hold-down strips are offset so that all parts of all straws are scrubbed. Of course the balls 31 on the chains prevent movement of the straws longitudinally of the chains and consequently the only movement possible for the straws relative to the chains is a rotary motion which is, in fact, caused by the brushes 57 and 58 rotated at a speed much greater than the speed of translation of the straws by the chains. The brushes 57 and 58 may be rotated counterclockwise with the peripheral velocity thereof substantially greater than the translational velocity of the chains so that the brushes not only scour the straws as they pass through the compartment 56 but also rotate them so that all portions of the exterior of the straws are in fact cleaned and scrubbed.
Following the cleaning and disinfecting compartment 56 there is provided a rinse compartment 86 disposed between the partitions 47 and 48. Within this rinse compartment there is transversely disposed a slotted or perforated pipe 87 having one end extending through the ball wall 12 of the housing and the other end capped. Clean water or other fluid rinse is supplied through this pipe 87 and is sprayed downwardly upon the straws 41 transported across the bottom of the compartment 86 by the chains 28 and 29. Within the rinse chamber 86 there is also provided an extension of the strip 66 and all elements thereof in the first part of the chamber 86 whereby the straws in the rinse compartment have one end thereof passing between the strips 68 and clean water pipes 88 force filtered water through the slits 81 into the straws in the rinse compartment to thus rinse out the inside of the tubes therein. This structure of the rinse compartment is not illustrated inthe drawings inasmuch as it is the same as the structure in the cleaning and disinfecting compartment as illustrated in FIGS. 2 and 3.
Following complete rinsing of the straws as they pass through the rinse compartment 86, the present invention provides for completly drying the straws both internally and externally thereof. To this end there is provided an internal drying compartment or chamber 91 between the transverse partitions 48 and 49. This compartment may be quite short in length and includes wiping means 92 which may take the form of a plurality of thin strips of resilient material such as rubber, secured along the upper edges thereof to the lower portion of the partition 48 in the compartment 91 so that the lower edges of these resilient strips depend transversely across the compartment. As the chains move the straws 41 past the strips 92, the straws will be wiped by the strips to remove droplets of water adhering to the exterior of the strips. Following this wiping operation in the compartment 91, there are provided one or more fine orifices 93 aligned with the ends of the straws as they pass across the bottom of the compartment and high pressure air is applied through these orifices to thus blow as a jet forcibly through the interior of the straws and thus remove droplets of water that may remain therein.
Following the inner drying compartment 91 there is provided an outlet hopper 96 disposed between the partition 49 and end wall 14. This hopper has an upwardly inclined floor 97 with longitudinal slots therein through which the chains 28 and 29 pass so that movement of the chains through the hopper causes the straws carried thereby to be pushed onto the inclined floor upwardly from the chains as they pass through the inclined floor so as to leave the cleaned and disinfected straws in the hopper. The straws will thus pile upin the hopper, as shown, while yet in parallel alignment with each other and the back wall 12 of the housing at the hopper is formed with a large number of perforations, such as by the insertion of a screen 98 in a large opening therein with warm air being blown therethrough so as to complete drying of the straws in the hopper. The front wall 17 is also perforated at the exit hopper in order for this air to readily escape from the housing.
Provision is also made in the present invention for the automatic loading of magazines or the like with cleaned, disinfected and dried straws. To this end the housing is provided with means for receiving a magazine 101 immediately above the exit hopper 96. The magazine 101 has a slidably disposed bottom wall 102 which may be retracted, as illustrated in FIG. 1, to leave the interior of the magazine open to the hopper at the top thereof. The magazine 101 may also include an apertured flange 103 for fitting about a bolt and nut 104 on the housing to lock the magazine onto the housing. As the straws pile up in the hopper they will thus be moved upwardly into the magazine following the complete drying operation in the exit hopper. At such time as the magazine is filled or filled to desired capacity the floor 102 is then slid into closing position to the magazine so that the latter may be removed from the apparatus with straws therein ready for further use. Such a magazine may then be emptied into straw filling apparatus such as that disclosed in U.S. Patent Application Ser. No. 384,937 without the straws being touched by human hands since they were placed in the inlet hopper of the present invention.
The mechanical configuration of a preferred embodiment of the present invention has been described above and reference is now made to FIGS. 4 and 5 illustrating the flow of fluid in the apparatus hereof and the drive means for elements of the apparatus. Preferably cleaning and rinsing of the straws and the apparatus of the present invention is accomplished with water, although some other type of fluid can be employed. A water supply 111 is shown to pass water under pressure through a filter 112 into a manifold 113. A source 114 of detergent or other cleansing means and disinfectant solution is connected to one inlet of a conventional metering pump 116 having the other inlet connected to the manifold 113 so as to provide a controllable desired mixture of cleanser, disinfectant and water which is then discharged from the pump to the tube 76 and inlet pipes 82 of the cleaning and disinfecting chamber 56. Clean, fresh water from the manifold 113 is also connected directly to the inlet pipes 87 and 88 of the rinse chamber. It will thus be seen that water containing a cleanser and disinfectant is forced into the chamber 56 through the pipes 76 and 82 for the purposes described above and also clean water is forced under pressure through the pipes 87 and 88 into the rinse chamber 86 for rinsing the inside and outside of straws.
The chains 28 and 29 are moved across the bottoms of the above-described compartments by rotation of one of the notched cylinders 26 or 33 and in FIG. 5 there is shown a motor 121 disposed exteriorly of the housing 11 and driving the shaft 25 of the notched cylinder 26. This connection of motor and shaft may be made in any one of a variety of ways such as by gears, belts, chains or the like, and the motor may be variable speed motor with control means thereon for adjusting the rate of travel of the chains through the apparatus of the present invention. Preferably a clutch 122 is included in the drive train so that no undue damage could result from possible jamming of the apparatus. The brushes 57 and 58 of the present apparatus are rotated as, for example, by an exterior motor 123 through a chain drive or the like into connection with the brush shafts 59. The interior drying of the straws in the chamber 91 is accomplished by a high velocity jet of air forced through the straws and such jet is preferably provided by a separate high velocity blower 126 mounted exteriorly of the housing at the back wall 12 thereof and having an outlet pipe 127 extending through such wall into communication with the jets 93 within the chamber 91. The final drying of the straws in the outlet hopper 96 is accomplished by the passage of heated air longitudinally of the straws therein and to this end there is provided a blower 131 passing air through a heater 132 and exhausting through the perforated opening in the back wall of the housing at the outlet hopper 96.
The liquids employed in the apparatus of the present invention will be seen to fall from the chambers 56 and 86 into the sump 52 at the bottom of the housing inasmuch as there are no floors provided in these chambers. The sump 52 is preferably provided with a low point in the bottom thereof so that liquid may be readily drained from the sump, as shown.
It will be appreciated that the present invention, as described above in connection with a preferred embodiment thereof, operates to thoroughly clean, disinfect and dry poultry insemination straws without the necessity of any human intervention. The apparatus is fully automatic so that a large number of straps may be passed therethrough to provide necessary high output for this field. Additionally the apparatus hereof provides for automatic loading of magazines with the dry, clean straws so that the latter may then be readily employed in further artificial insemination operations without the necessity of handling same and this is advantageous in reducing the risk of possible straw contamination by human handling.
Although the present invention has been illustrated with respect to a single preferred embodiment, it will be apparent to those skilled in the art that various modifications and alterations may be made in such showing without departing from the concepts of this invention. It is thus not intended to limit the invention to the precise details of illustration nor terms of description.
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Apparatus for scrubbing, rinsing, drying and packaging very fine, hollow cylinders or straws employed in artificial poultry insemination, includes straw transport means moving straws in fixed orientation through successive cycles including interior washing and drying and magazine loading entirely automatically.
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BACKGROUND OF THE INVENTION
Amorphous fluoropolymers are a class of plastic materials with low surface energy and low dielectric constant that are characterized as exceptionally chemically inert and thermally stable due to their strong carbon-fluorine and carbon-carbon bonds. Most of these polymers have low reflective index with high transparency in a wide range of wavelength from 200 to 2000 nm. Amorphous fluoropolymers are widely used in different fields such as coatings in optics, insulators in electronics, protection material in chemical industries, and semiconductors. [1]
Applying amorphous fluoropolymers in nano devices is in high demand for many emerging high-tech applications; especially in pharmaceutical products, and electronics. So far, all currently available techniques to pattern amorphous fluorinated polymers are based on etching by high energy radiation sources, such as focused laser light, resulting in micro structures with aspect ratios less than 2; synchrotron radiation, giving micro structures which reach aspect ratios between 10 and 70; focused ion beams, with 5 nm spatial resolution. In addition, high doses of electron beam radiation have been reported to cause photodegradation of the polymer with ˜200 nm feature resolution. [2-4]
However, lithography-based nano-patterning of fluorinated polymers still remains a challenge, mainly because of the chemical inertness. No suitable solvents to chemically etch, or develop this type of polymer have been reported.
The method presented here is a novel approach to achieve patterning of fluoropolymer surfaces with micrometer and submicrometer feature resolution by means of chemically developing surface-deposited and high-energy radiation exposed films of such polymers in the fashion of a negative lithographic resist process.
SUMMARY OF THE INVENTION
This invention provides a method to create patterns of amorphous fluoropolymer on a solid substrate. The invention detailed here allows for the generation of amorphous fluoropolymer patterns on surfaces, featuring high resolution with feature sizes ranging from the micrometer to the low nanometer size scale. This pattern generation is achieved by treating thin films of amorphous fluoropolymer, which are previously exposed to high energy radiation, with a developer. The developer is chosen to selectively dissolve the unexposed polymer areas, while leaving the exposed areas unchanged. In order to obtain patterned surfaces, an amorphous fluoropolymer film is deposited on a solid substrate, exposed with a pre-defined pattern, and developed to liberate the desired pattern on the substrate surface. The procedure follows the principle of a negative lithographic resist, i.e., unexposed resist is removed from the substrate surface in the development process, and only the exposed areas remain on the substrate. A change in chemical structure, i.e., chemical degradation, of the exposed polymer, which is caused by the high-energy radiation, is responsible for a decrease in solubility in the developer that we use to produce the fluoropolymer pattern on the surface.
In the first aspect, an amorphous fluoropolymer film is deposited as a thin layer on a solid substrate.
In one embodiment, the amorphous fluoropolymer is Teflon AF.
In one preferred embodiment, the amorphous fluoropolymer is Teflon AF 1600.
In another preferred embodiment, the amorphous fluoropolymer is Teflon AF 2400.
In one aspect, the solid substrate is transparent.
In a preferred embodiment, the transparent substrate is glass, quartz or mica.
In a preferred embodiment, the transparent substrate is plastics.
In one aspect, the solid substrate is opaque.
In one embodiment, the opaque substrate is a metal, semiconductor, glass or ceramics.
In one preferred embodiment, the opaque substrate is Silicon (Si).
In another embodiment, the opaque substrate is Silicon oxide (SiO2).
In another embodiment, the opaque substrate is Silicon carbide (SIC).
In another embodiment, the opaque substrate is Silicon-germanium (SiGe).
In another embodiment, the opaque substrate is germanium (Ge).
In another embodiment, the opaque substrate is gallium-antimonide (GaSb).
In another embodiment, the opaque substrate is gallium-arsenide (GaAs).
In another embodiment, the opaque substrate is gallium phosphide (GaP).
In another embodiment, the opaque substrate is gallium-nitride (GaN).
In another embodiment, the opaque substrate is indium phosphide (InP).
In another embodiment, the opaque substrate is indium arsenide (InAs).
In another embodiment, the opaque substrate is indium antimonide (InSb).
In another embodiment, the opaque substrate is cadmium selenide (CdSe).
In another embodiment, the opaque substrate is cadmium telluride (CdTe).
In another embodiment, the opaque substrate is cadmium sulphide (CdS).
In another embodiment, the opaque substrate is zinc selenide (ZnSe).
In another embodiment, the opaque substrate is zinc sulphide (ZnS).
In another embodiment, the opaque substrate is zinc telluride (ZnTe).
In another embodiment, the opaque substrate is zinc oxide (ZnO).
In another embodiment, the opaque substrate is Strontium titanate (SrTiO3).
In one aspect, the solid substrate is coated with a thin-film.
In one embodiment, the solid substrate is coated with a conductive thin-film.
In one preferred embodiment, the solid substrate is coated with an oxide.
In another preferred embodiment, the solid substrate is coated with tin doped indium oxide (ITO).
In another embodiment, the solid substrate is coated with zinc oxide (ZnO).
In another embodiment, the solid substrate is coated with aluminum doped zinc oxide (ZnO:Al).
In another embodiment, the solid substrate is coated with gallium doped zinc Oxide (ZnO:Ga).
In another embodiment, the solid substrate is coated with is indium doped zinc oxide (IZO).
In another embodiment, the solid substrate is coated with indium doped cadmium oxide (ICO).
In one preferred embodiment, the solid substrate is coated with a nitride.
In another embodiment, the solid substrate is coated with graphene.
In another embodiment, the solid substrate is coated with carbon nano fibers.
In another embodiment, the solid substrate is coated with a metal.
In another embodiment, the solid substrate is coated with a polymer.
In one preferred embodiment, the solid substrate is coated with Poly(3,4-ethylenedioxythiophene) (PEDOT).
In another preferred embodiment, the solid substrate is coated with Poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT: PSS).
In another embodiment, the solid substrate is coated with poly(4,4 dioctylcyclopentadithiophene).
In another embodiment, the solid substrate is coated with Poly(4,4-dioctylcyclopentadithiophene) doped with iodine.
In another embodiment, the solid substrate is coated with Poly(4,4 dioctylcyclopentadithiophene) doped with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ).
In one aspect, the thin layer of amorphous fluoropolymer is fabricated by a common thin film deposition method.
In one embodiment, the thin layer of amorphous fluoropolymer is fabricated spin coating.
In a preferred embodiment, the thin layer of amorphous fluoropolymer is fabricated by spin coating, for which the amorphous fluoropolymer is applied as a solution of Teflon AF 1600 in a fluorinated solvent.
In another preferred embodiment, the thin layer of amorphous fluoropolymer is fabricated by spin coating, for which the amorphous fluoropolymer is applied as a solution of Teflon AF 2400 in a fluorinated solvent.
In another embodiment, the thin layer of amorphous fluoropolymer is fabricated by meniscus coating.
In another embodiment, the thin layer of amorphous fluoropolymer is fabricated by capillary coating.
In another embodiment, the thin layer of amorphous fluoropolymer is fabricated by extrusion coating.
In another embodiment, the thin layer of amorphous fluoropolymer is fabricated by patch coating.
In another embodiment, the thin layer of amorphous fluoropolymer is fabricated by extrude-and-spin coating.
In one aspect, the thickness of amorphous fluoropolymer film is in the range of 10 nm-50 nm.
In one aspect, the thickness of amorphous fluoropolymer film is in the range of 50 nm-250 nm.
In another aspect, the thickness of amorphous fluoropolymer film is in the range of 250 nm-5 μm.
In another aspect, the thickness of amorphous fluoropolymer film is in the range of 5 μm-500 μm.
In one aspect, the thin Layer of amorphous fluoropolymer is exposed by high energy radiation.
In one aspect, the source of radiation is an electron beam.
In another aspect, the source of radiation is an x-ray beam.
In another aspect, the source of radiation is synchrotron radiation.
In another aspect, the source of radiation is a focused ion beam.
In another aspect, the source of radiation is a laser beam.
In one main aspect, the amorphous fluoropolymer film is brought in contact with a fluid developer to achieve development.
In one main aspect, the exposed amorphous fluoropolymer film is developed with a fluorinated hydrocarbon solvent.
In a preferred embodiment, the fluorinated solvent is Perfluoro (2-butyltetrahydrofuran).
In one embodiment, the fluorinated solvent is perfluorononane (C 9 F 20 ).
In another embodiment, the fluorinated solvent is perfluoro-2-butyltetrahydrofuran (C 8 F 16 O)
In another embodiment, the fluorinated solvent is Hexafluorobenzene (C 6 F 6 ).
In another embodiment, the fluorinated solvent is perfluorodecalin (C 10 F 18 ).
In another embodiment, the fluorinated solvent is perfluorooctyl bromide (C 8 BrF 17 ).
In another embodiment, the fluorinated solvent is 2H,3H-Decafluoropentane (C 5 H 2 F 10 ).
In another embodiment, the fluorinated solvent is benzotrifluorde (C 7 H 5 F 3 ).
In another embodiment, the fluorinated solvent is octafluorotoluene (C 7 F 8 ).
In another embodiment, the fluorinated solvent is hexadecafluoroheptane (C 7 F 16 ).
In another embodiment, the fluorinated solvent is Hexadecafluoro(1,3-dimethylcyclohexane)
In another embodiment, the fluorinated solvent is perfluoro-1,3-dimethylcyclohexane (C 8 F 16 ).
In another embodiment, the fluorinated solvent is 2H,3H-Decafluoropentane.
In one embodiment, the fluorinated solvent is (trifluoromethyl)-, 1-butanamine.
In one aspect, the exposed amorphous fluoropolymer film is developed with a mixture of different solvents.
In one preferred embodiment, the mixture is composed of Perfluoro (2-butyltetrahydrofuran) and hexadecafluoroheptane.
In one embodiment, the mixing ratio is in a range between 10:1 and 1:10.
In one preferred embodiment, the mixing ratio is 1:1.
In one aspect, the developer is applied by a spraying or nebulizing technique.
In another aspect, the developer is applied by a dipping or immersion technique.
In another aspect, the developer is applied by a flow technique.
In another aspect, the developer is applied locally by a microflow device.
In one aspect the contact between the exposed fluoropolymer layer and the developer is kept for a determined period of time to achieve development.
In one embodiment, the development time comprises a duration between 1 second and 10 minutes.
In a preferred embodiment, the development time is 30 seconds.
In another preferred embodiment, the development time is 2 minute.
In one aspect, the developer is held at a determined temperature between melting point and flash point during development.
In a preferred embodiment, the development temperature is fixed at 20° C.
In another embodiment, the development temperature is fixed at 60° C.
In another embodiment, the development temperature is changed from 20° C. to 60° C. during the development.
In one aspect, the substrate carrying the exposed amorphous fluoropolymer film is held still during development.
In another aspect, the substrate carrying the exposed amorphous fluoropolymer film is agitated during development.
In another aspect, the substrate carrying the exposed amorphous fluoropolymer film is sonicated during development.
DEFINITIONS
Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by a person skilled in the art to which this invention belongs. The following references provide one of skill with a general definition of many of the terms used in this invention: The Cambridge Dictionary of Science and Technology (Walker ed., 1988), Britannica encyclopedia/Academic Edition online. As used herein, the following terms have the meanings ascribed to them below, unless specified otherwise. In this disclosure, “comprises,” “comprising,” “containing” and “having” and the like can have the meaning ascribed to them in U.S. Patent law and can mean “includes,” “including,” and the like; “consisting essentially of” or “consists essentially” likewise has the meaning ascribed in U.S. Patent law and the term is open-ended, allowing for the presence of more than that which is recited so long as basic or novel characteristics of that which is recited is not changed by the presence of more than that which is recited, but excludes prior art embodiments.
By “fluoropolymer” is meant to refer to a carbon polymer containing a large portion of carbon-fluorine bonds in its repeating monomer.
By “amorphous fluoropolymer” is meant to refer a fluoropolymer in which the molecules are oriented randomly.
By “negative lithographic resist” is meant to refer to a chemical that is sensitive to interaction with radiation in a way that its solubility in a developer decreases when exposed to electromagnetic or particle radiation.
By “exposure” is meant to refer to the interaction of radiation and radiation-sensitive resist, which defines the exposed (irradiated) areas in a lithographic resist film.
By “radiation” is meant to refer to the propagation of energy in the form of waves, rays or particles.
By “high energy radiation” is meant to refer to the radiation with energy of more than one thousand electron volts.
By “thin film” is meant to refer to a layer of material with thickness less than one millimeter.
By “pattern” is meant to refer to the design made up of an arrangement of regular shapes, such as lines, circles, squares, polygons, or irregular shapes, which is typically repeated at regular intervals over the substrate surface.
By “chemical degradation” is meant to refer to a chemical process by which a compound is broken down into molecular or atomic fragments.
By “aspect ratio” is meant to refer to the ratio between the height and the width of a structure.
By “resolution” is meant to refer to the minimum distance at which features can be distinguished as individuals. The resolution is limited by the width of the exciting beam and by the interaction volume in a solid.
By “feature size” is meant to refer to the size of one or more individual elements of a pattern.
By “development” is meant to refer to a process which liberates the pattern from the lithographic resist film after exposure.
By developer is meant to refer to a liquid or fluid which is used to achieve development, typically by dissolving and removing the exposed (positive developer) or unexposed (negative developer) areas in the lithographic resist film.
By “fluorinated solvent” is meant to refer to a hydrocarbon solvent in which some or all of the hydrogen atoms are replaced by fluorine atoms.
By “Perfluorinated solvent” is meant to refer to a hydrocarbon solvent in which all of the hydrogen atoms are replaced by fluorine atoms.
By “microflow device” is meant to refer to a microscale device controlling or sensing flow in the order of μl/min to nl/min.
By “substrate” is meant to refer to the material on which a process is conducted.
By “coating” is meant to refer to a thin layer of something spreads over a substrate or surface.
BRIEF DESCRIPTION OF DRAWINGS
In the accompanying drawings:
FIGS. 1A-1E show schematically top views of the substrate in the process of substrate preparation and surface patterning.
FIG. 1A illustrates the top view of a clean solid substrate.
FIG. 1B illustrates the top view of a clean solid substrate coated with a thin layer of a transparent conductive coating.
FIG. 1C illustrates the top view of a solid substrate after coating with a thin layer of a transparent conductive coating and a thin layer of an amorphous fluoropolymer.
FIG. 1D illustrates the top view of a coated substrate after exposure by high energy radiation, defining the pattern.
FIG. 1E illustrates the side view of a coated and exposed substrate after development with developer.
FIGS. 1F-1J show schematically side views of the substrate in the process of substrate preparation and surface patterning.
FIG. 1F illustrates the side view of a clean solid substrate.
FIG. 1G illustrates the side view of a clean solid substrate coated with a thin layer of a transparent conductive coating.
FIG. 1H illustrates the side view of a solid substrate after coating with a thin layer of a transparent conductive coating and a thin layer of an amorphous fluoropolymer.
FIG. 1I illustrates the side view of a coated substrate after exposure by high energy radiation, defining the pattern.
FIG. 1J illustrates the side view of a coated and exposed substrate after development with developer.
FIG. 2A illustrates schematically a set-up to deposit a thin layer of an amorphous fluoropolymer onto a solid substrate.
FIG. 2B illustrates schematically a set-up to define the desired pattern on the fluoropolymer by exposing to a high energy radiation
FIGS. 2C-2E are schematic representations showing possible methods of pattern development.
FIG. 2C shows schematically pattern development by dipping of the exposed substrate into developer.
FIG. 2D shows schematically pattern development by spraying the exposed substrate with developer.
FIG. 2E shows schematically localized pattern development by means of a micropipette and a controlled flow of developer.
FIG. 2F shows schematically a patterned substrate after development.
FIG. 3A shows an optical microscopy image of a patterned amorphous fluoropolymer substrate after exposure by electron beam radiation.
FIG. 3B shows an atomic force 2D micrograph of a patterned amorphous fluoropolymer substrate after exposure by electron beam radiation.
FIG. 3C shows an atomic force 3D micrograph of a patterned amorphous fluoropolymer substrate after exposure by electron beam radiation.
FIG. 4A shows an optical microscopy image of an e-beam exposed amorphous fluoropolymer-coated substrate after development.
FIG. 4B shows an atomic force 2D micrograph of an e-beam exposed amorphous fluoropolymer-coated substrate after development.
FIG. 4C shows atomic force 3D micrograph of an e-beam exposed amorphous fluoropolymer-coated substrate after development.
DESCRIPTION OF THE DRAWINGS
FIG. 1 displays the process of substrate preparation, comprising spin coating of an amorphous fluoropolymer onto a solid substrate. For clarity both plane and profile views are presented. The clean solid substrate ( 0100 ) is coated with a thin layer of a transparent conductive coating ( 0101 ) and then a thin layer of an amorphous fluoropolymer ( 0102 ) is spun on top of the coating. The desired pattern is exposed by electron beam radiation ( 0103 ). After development all the unexposed areas is dissolved into the developer and only exposed areas are remained ( 0104 ).
FIG. 2 provides an exemplary illustration of the set-up of the method. The coated solid substrate ( 0200 ) is placed on a spin-coater ( 0201 ) which rotates at a specific speed ( 0202 ). The amorphous fluoropolymer ( 0203 ) is put onto the substrate by a pipette ( 0204 ). The solid substrate covered by fluoropolymer ( 0205 ) is exposed by a high energy radiation ( 0207 ) producing the desired pattern ( 0206 ) at exposed areas. After exposure the substrate can be dipped into a container ( 0208 ) filled with the fluorinated hydrocarbon solvent as developer ( 0209 ), or the fluorinated hydrocarbon solvent can be sprayed ( 0210 ) by a nozzle ( 0211 ) placed above the exposed areas. The developer can also be applied by localized developing system including a micropipette ( 0212 ) and a controlled flow of developer ( 0213 ). After development, all the unexposed fluoropolymer is dissolved by the developer and only the exposed fluoropolymer ( 2014 ) is remained on the surfaces, surrounding by transparent conductive coating ( 2015 ).
FIG. 3 shows optical microscopic image ( FIG. 3A ) and atomic force 2D and 3D macrographs ( FIG. 3B and FIG. 3C ) of a patterned amorphous fluoropolymer exposed by electron beam radiation. An amorphous fluoropolymer is spun onto a solid substrate ( 0300 ) and desired pattern is exposed by e-beam radiation ( 0301 ). Gold alignment marks ( 0302 ) are used to find the structure easier.
FIG. 4 shows optical microscopic image ( FIG. 3A ) and atomic force 2D and 3D macrographs ( FIG. 3B and FIG. 3C ) of e-beam exposed amorphous fluoropolymer after development by fluorinated hydrocarbon developer. After development only exposed areas of amorphous fluoropolymer ( 0401 ) remain on the transparent conductive coating ( 0400 ) while the rest of unexposed fluoropolymer is removed by the developer. Gold alignment marks ( 0402 ) are used to find the structure easier.
DETAILED DESCRIPTION
The embodiments of this method provide means for the generation of amorphous fluoropolymer patterns on solid surfaces, featuring high resolution with feature sizes ranging from the micrometer to the low nanometer size scale.
First a solid surface ( 0100 ) is selected and cleaned ( FIG. 1 ). In one aspect the solid substrate is transparent. In a preferred embodiment the transparent solid substrate is glass. In other embodiments the transparent solid substrate is quartz, mica or polymer. In another aspect the solid substrate is opaque including metal, semiconductor amorphous materials and ceramics. Second, the solid substrate can be coated with a thin layer of a conductive coating ( 0101 ). In one aspect the transparent conductive coating is an oxide. In a preferred embodiment the transparent coating is indium tin oxide (ITO). In other embodiments the transparent oxide is indium doped cadmium oxide (ICO), aluminum doped zinc oxide (ZnO:Al), gallium doped zinc Oxide (ZnO:Ga), indium doped zinc oxide (IZO) or zinc oxide (ZnO). In other aspects the conductive coating is graphene, carbon nanofiber, polymer or metal. Third, a thin layer of an amorphous fluoropolymer ( 0203 ) is deposited on the solid substrate coated with a thin conductive film ( 0200 ). In one aspect the amorphous fluoropolymer is Teflon AF 1600. In another aspect the amorphous fluoropolymer is Teflon AF 2400. In a preferred embodiment thin layer of the amorphous fluoropolymer is generated by spin-coating ( FIG. 2A ). In other embodiments the thin layer of amorphous fluoropolymer is generated by meniscus coating, capillary coating, extrusion coating, extrude-and-spin coating and patch coating. In a preferred embodiment the thickness of the amorphous fluoropolymer is 500 nm. In other embodiments the thickness of the amorphous fluoropolymer is in the range of 10 nm to 500 μm. Fourth, the substrate coated with amorphous fluoropolymer ( 0205 ) is exposed by a high energy radiation ( 0207 ) producing the desired pattern at exposed areas ( 0206 ) ( FIG. 2B ). In a preferred embodiment the high energy radiation is an electron beam, which is common equipment in most fabrication facilities. In other embodiments the high energy radiation is an X-ray beam, synchrotron radiation, laser radiation, or a focused ion beam. Finally, the exposed amorphous fluoropolymer film is developed with a fluorinated hydrocarbon solvent ( 0209 ). In a preferred embodiment the fluorinated hydrocarbon solvent is perfluoro (2-butyltetrahydrofuran), but the developer can comprise a variety of other perfluorinated solvents, including perfluoro-2-butyltetrahydrofuran (C 8 F 16 O), hexafluorobenzene (C 6 F 6 ), perfluorodecalin (C 10 F 18 ), 2H,3H-Decafluoropentane (C 5 H 2 F 10 ), benzotrifluorde (C 7 H 5 F 3 ), (trifluoromethyl)-, 1-butanamine, hexadecafluoroheptane (C 7 F 16 ), Hexadecafluoro(1,3-dimethylcyclohexane), perfluoro-1,3-dimethylcyclohexane (C 8 F 16 ), 2H,3H-Decafluoropentane octafluorotoluene (C 7 F 8 ) and is perfluorooctyl bromide (C 8 BrF 17 ). In another aspect the developer is a mixture of fluorinated hydrocarbon solvents in order to regulate the duration of the development process. Such a mixture can comprise, for example, perfluorononane and perfluoro-2-butyltetrahydrofuran (C 8 F 16 O) in a 1:1 (v/v) mixture. The exposed fluoropolymer coated substrates are brought in contact with the developer, until the exposed pattern is liberated from the amorphous fluoropolymer film. In a preferred embodiment the exposed surface is immersed, or dipped into fluorinated hydrocarbon solvent ( FIG. 2C ). In other embodiments the developer can be applied by spraying ( FIG. 2D ), or locally on selected substrate surface areas by a microflow needle or microfluidic device ( FIG. 2E ). During development, unexposed amorphous fluoropolymer is dissolved in the fluorinated hydrocarbon solvent, such that only the exposed areas ( 2015 ) remain on the substrate after development ( FIG. 2F ). Development can be controlled by adjusting development parameters. In one aspect, the temperature is regulated. Temperature can be increased to increase the solubility of the unexposed fluoropolymer in the developer. In another aspect, the developing time is regulated. For each amorphous fluoropolymer, an optimal development time has to be determined, in order to avoid over- or underdevelopment. In yet another aspect the substrate carrying the exposed amorphous fluoropolymer film is either held still, or is agitated, or is sonicated, in order to improve the contact between the developer liquid and the amorphous fluoropolymer film, and to facilitate the removal of dissolved material from the surface. After the development is complete, the substrates are washed, dried and characterized according to common fabrication procedures.
Example
A non-limiting example of the invention is presented herein. FIG. 3 shows a thin layer of Teflon AF 1600 after exposure by e-beam radiation. The desired pattern on 500 nm thick Teflon AF 1600 film is exposed by 100 keV accelerated electron beam radiation with a 500-1500 μC/cm 2 dose range. In FIG. 3A , a micrograph of an exposed Teflon film on a ITO/glass substrate is displayed. Exposed areas are visible, due to the structural change in the exposed Teflon AF ( 0301 ), it can be distinguished from the unexposed Teflon AF ( 0300 ). Alignment marks ( 0302 ) help to locate the exposed regions. FIG. 3B is an AFM topography image of a locally exposed Teflon AF film. The unexposed areas ( 0300 ) appear bright, the exposed areas ( 0301 ) appear dark. The brightness encodes the absolute hight, showing a hight difference in the nanometer range between exposed and unexposed Teflon AF. After a 2 minute development at 20° C., subsequent to exposure, by means of perfluoro (2-buthyltetrahydrofuran), the e-beam exposed Teflon remains on the substrate while the unexposed Teflon has been removed by the developer solvent. FIG. 4A is a micrograph of the exposed, and subsequently developed Teflon film on a ITO/glass substrate. Exposed areas ( 0401 ) are visible as brighter areas, due to removed unexposed Teflon AF, easily distinguished from the uncoated substrate ( 0400 ). Alignment marks ( 0402 ) facilitate locating the exposed and developed pattern. FIG. 4B is a AFM 2D-topography image, and FIG. 4C a AFM 3D-topography image of an exposed and developed Teflon AF pattern. The developed pattern ( 0401 ) appears bright, and the substrate areas ( 0400 ) appear dark. The gap between the two exposed areas is ˜50 nm wide.
Materials
Substrate:
Unbeveled, CNC (Computer Numerical Control) precision cut, thin borosilicate glass substrate (diameter: 50 mm (+/−0.25)×50 mm (+/−0.25); thickness: 0.175 mm (+/−0.015)) coated with ITO-coating (20+/−5 Ohms/sq.) with no SiO 2 layer from Präzisions Glas & Optik (Iserlohn, Germany)
Chemicals:
Teflon AF solution grade 601S2-100-6 1600 (6% (w/w) solids contents, based on Teflon AF1600, glass transition temperature Tg=160° C.) from Dupont Chemicals (Wilmington, US); HMDS (Hexamethyldisiloxane) from Micro Resist Technology GmbH (Berlin, Germany); Perfluoro (2-buthyltetrahydrofuran) from Tokyo Chemical Industry (Tokyo, Japan); Fluorinert FC-770 (CAS Number 86508-42-1) from Sigma Aldrich (Missouri, USA).
Equipment:
The Electron Beam Lithography system EBL-JEOL JBX-9300FS, from JEOL, Tokyo, Japan was used as radiation source for exposure. Electron Beam Evaporator (AVAC-HVC600) was used for the deposition of alignment marks. Dry plasma etching system (BatchTop PE/RIE m/95, PlasmaTherm/Advanced Vacuum, USA, was used for pre-treatment of the substrates. Standard clean-room fabrication methods and equipment was used for common substrate preparation steps.
Microscopy:
Scanning Electron microscope (Leo Ultra 55 FEG, Zeiss); AFM images were recorded using a Veeco Dimension 3100 SPM scanning probe microscope in tapping mode with a NSG01 DLC probe (NT-MDT Europe BV, Netherlands), The transmission optical micrographs were recorded using an Olympus reflected light optical microscope, with a LMPLFL50XBD objective, and a SONY ST50CCD Video camera.
Process
The ITO substrate was cleaned by spraying with acetone and subsequently isopropanol. To remove all the possible organic contaminants, the substrate was plasma treated (10 sccm oxygen, 500 mbar, 50 W) for 10 min. HMDS (Hexamethyldisiloxane) was spin-coated onto the substrate (3000 rpm) and baked on a hot plate (110° C. for 90 s) to improve the adhesion of Teflon to the substrate. Teflon AF 1600 ( 0203 ) was spin-coated ( 0202 ) onto the substrate (2000 rpm) and baked for 15 min at 180° C. beyond the glass transition temperature of Teflon AF. The substrate was then loaded into an electron beam lithography system (EBL-JEOL JBX-9300FS) where it was exposed by electron beam radiation ( 0207 ) using a pre-designed pattern. After exposure, the substrate was immersed in perfluoro (2-butyl tetrahydrofuran) ( 0209 ) in a glass container ( 0208 ). The unexposed surface area dissolved in the developer solvent, while the exposed pattern ( 0206 ) remained on the surface. After 2 min of development, the substrate was removed from the developer bath, washed with FC770, and dried by air blowing. The surfaces are stored under nitrogen.
REFERENCES
1. Amorphous fluoropolymers—A new generation of products. Korinek, p. M. 1994, Macromolecular symposia, pp. 61-65.
2. Micro- and Nano-Scale Fabrication of Fluorinated Polymers by Direct Etching Using Focused Ion Beam. Fukutake, N., et al. s.l.: Japanese Journal of Applied Physics, 2010, Vol. 49.
3. Direct Electron-Beam Patterning of Teflon AF. Karre, V., et al. 2, s.l.: Transactions on Nanotechnology, 2009, Vol. 8.
4. Nano- and micro-fabrication of perfluorinated polymers using quantum beam technology. Miyoshi, N., et al. s.l.: Radiation Physics and Chemistry, 2011, Vol. 80. 230-235.
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Here we disclose a lithographic pattern development process for amorphous fluoropolymers. Amorphous fluoropolymers are a class of plastic materials with high chemical inertness and favorable optical properties. Exposure of surface-deposited layers of such polymer with high energy radiation leads to a change in the chemical structure of the polymer, which selectively compromises the solubility of the exposed areas in fluorinated organic solvents. Micro- and nanopatterning with a feature size down to <50 nm was achieved by dissolving and removing unexposed amorphous fluoropolymer from exposed, surface deposited films. The amorphous fluoropolymer functions thus as a negative resist.
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BACKGROUND
[0001] The present disclosure is directed to wellbore lithology fractionation technology, more particularly to fracture characterization using reservoir monitoring devices, and more particularly, but not by way of limitation, to a system and method for using several sensors attached below a fracturing tool string.
[0002] A wide variety of downhole tools may be used within a wellbore in connection with producing hydrocarbons from a hydrocarbon formation. Downhole tools such as frac plugs, bridge plugs, and packers, for example, may be used to seal a component against casing along the wellbore wall or to isolate one pressure zone of the formation from another.
[0003] Fracturing is a wellbore service operation to break or fracture a production layer with the purpose of improving flow from that production layer. In the case that multiple zones of production are planned, fracturing may be conducted as a multi-step operation, for example positioning fracturing tools in the wellbore to fracture a first zone, pumping fracturing fluids into the first zone, repositioning the fracturing tools in the wellbore to fracture a second zone, pumping fracturing fluids into the second zone, and repeating for each of the multiple zones of production. Fracturing fluids sometimes propagate into water bearing formations, which is undesirable. Water must be separated at the surface from oil or gas and properly disposed of, imposing undesirable expenses on the production operation. If the production fluids are pumped to the surface, pumping energy, and hence money, is expended lifting the waste water product to the surface. What is needed is a system and method to detect during the course of a fracturing job when the fracturing fluid is propagating into a water bearing formation so that the fracturing job may be interrupted.
[0004] Fracturing tools may be withdrawn from the wellbore, and sensors may then be deployed into the wellbore and used to directly sense the results of fracturing. The sensors are withdrawn from the wellbore, the sensor information they have stored is downloaded to a computer, and the data is analyzed for use in planning future fracturing jobs in similar lithology structures or similar production fields. This two trip process is undesirable. What is needed is a system and method for co-deployment and co-retraction of fracturing tools and sensors for a fracturing service operation which may reduce the number of tool string trips into and out of the wellbore.
SUMMARY
[0005] Disclosed herein is a system for monitoring a wellbore service treatment, comprising a downhole tool operable to perform the wellbore service treatment; a conveyance connected to the downhole tool for moving the downhole tool in the wellbore, and a plurality of sensors operable to provide one or more wellbore indications and attached to the downhole tool or a component thereof via one or more tethers.
[0006] Further disclosed herein is a method of monitoring a wellbore service treatment, comprising conveying into a wellbore a downhole tool operable to perform the wellbore service treatment and a plurality of sensors operable to provide one or more wellbore indications attached to the downhole tool or a component thereof via one or more tethers, deploying the downhole tool at a first position in the wellbore for service, treating the wellbore at the first position; and monitoring an at least one wellbore indication provided by the wellbore sensors at the first position.
[0007] These and other features and advantages will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.
[0009] FIG. 1 a depicts a wellbore and a first tool string in a first stage of a fracturing job.
[0010] FIG. 1 b depicts a wellbore and a first tool string in a second stage of a fracturing job.
[0011] FIG. 1 c depicts a wellbore and a first tool string in a third stage of a fracturing job.
[0012] FIG. 1 d depicts a second tool string and fracturing configuration.
[0013] FIG. 1 e depicts a third tool string and fracturing configuration.
[0014] FIG. 1 f depicts a fourth tool string and fracturing configuration.
[0015] FIG. 1 g depicts a fifth tool string and fracturing configuration.
[0016] FIGS. 1 h and 1 i depict a sixth tool string and fracturing configuration.
[0017] FIG. 2 a illustrates a group of tiltmeters tethered together and hanging under a fracturing plug.
[0018] FIG. 2 b illustrates a group of tiltmeters attached to wellbore casing.
[0019] FIG. 2 c illustrates a group of tiltmeters each tethered separately to a fracturing plug.
[0020] FIG. 3 a depicts a data recovery component.
[0021] FIG. 3 b depicts an embodiment for tethering a sensor.
[0022] FIG. 4 is a flow chart illustrating a first method for monitoring a wellbore service treatment.
[0023] FIG. 5 is a flow chart illustrating a second method for monitoring a wellbore service treatment.
[0024] FIG. 6 is a flow chart illustrating a third method for monitoring a wellbore service treatment.
DETAILED DESCRIPTION
[0025] It should be understood at the outset that although an exemplary implementation of one embodiment of the present disclosure is illustrated below, the present system may be implemented using any number of techniques, whether currently known or in existence. The present disclosure should in no way be limited to the exemplary implementations, drawings, and techniques illustrated below, including the exemplary design and implementation illustrated and described herein.
[0026] FIGS. 1 a , 1 b , and 1 c show a wellbore 10 , which may be cased or uncased, and three stages of a wellbore service job corresponding to a first wellbore service configuration, in FIG. 1 a , a second wellbore service configuration, in FIG. 1 b , and a third wellbore service configuration, in FIG. 1 c . The exemplary wellbore service job depicted is a fracturing service job, but the present disclosure contemplates other wellbore service jobs such as acidizing, gravel packing, cementing, perforating, logging, conducting a survey to collect data, placing downhole sensors, installing and shifting the position of gas lift valves and flow valves, and other wellbore service jobs known to those skilled in the art. The exemplary fracturing job is directed to improving the flow from a zone of interest 14 . In an embodiment shown in FIGS. 1 a - c , a first tool string 8 comprises a bridge plug 16 and a plurality of sensors 18 —a first sensor 18 a , a second sensor 18 b , a third sensor 18 c , and a fourth sensor 18 d -attached to and hanging from the bridge plug 16 . The sensors 18 may be referred to as a sensor array or an array of sensors.
[0027] The bridge plug 16 may be generically referred to as a downhole tool. A wide variety of downhole tools may be used within a wellbore in connection with producing hydrocarbons from a hydrocarbon formation. Downhole tools such as frac plugs, bridge plugs, and packers, for example, may be used to seal a component against casing along the wellbore wall or to isolate one pressure zone of the formation from another. In addition, perforating guns may be used to create perforations through casing and into the formation to produce hydrocarbons. Downhole tools are typically conveyed into the wellbore on a wireline, tubing, pipe, or another type of cable. The first tool string 8 provides for the co-deployment and co-retraction of the bridge plug 16 and the sensors 18 using a tubing 20 .
[0028] The bridge plug 16 is an isolation tool that is operable to shut the well in, to isolate the zones above and below the bridge plug 16 , and to allow no fluid communication therethrough. The bridge plug 16 may be referred to as a sealable member. The sensors 18 may be tiltmeters, geophones, pressure sensors, temperature sensors, combinations thereof, or other sensors operable to sense wellbore characteristics which are known to those skilled in the art. The sensors 18 may each be supported by an individual or dedicated link or tether to the bridge plug 16 as shown in FIG. 2 c . Alternately, the sensors 18 may be chained or linked together, as shown in FIGS. 2 a and 2 b , wherein sensor 18 d is supported by a link or tether to sensor 18 c , sensor 18 c is supported by a link or tether to sensor 18 b , sensor 18 b is supported by a link or tether to sensor 18 a , and sensor 18 a is supported by a link or tether to the bridge plug 16 . While in this exemplary case four sensors 18 are shown to be employed, in other wellbore service jobs either more or fewer sensors 18 may be employed, for example 1 or more. The embodiments of FIGS. 2 a - c may be used with any of the tool string embodiments disclosed herein.
[0029] In the first wellbore service configuration of FIG. 1 a , the first tool string 8 has been lowered into the wellbore 10 , below the zone of interest 14 , via a tubing 20 . In another embodiment, the first tool string 8 may be conveyed into the wellbore 10 using wireline, slickline, coiled tubing, jointed tubing, or another conveyance known to those skilled in the art. The bridge plug 16 is placed to seal a lower boundary of the zone of interest 14 .
[0030] In the second wellbore service configuration of FIG. 1 b , the tubing 20 has been detached from the bridge plug 16 and withdrawn from the wellbore 10 . A stimulation service pump 22 is connected to a wellhead 24 and provides a fracturing fluid or other wellbore servicing fluid at a desirable pressure, temperature, and flow rate into the wellbore 10 . The fracturing fluid flows down the wellbore 10 , through wellbore casing perforations, into the zone of interest 14 . In an alternative embodiment as shown in FIGS. 1 h and 1 i , the tubing may remain attached to the sealable member 19 , e.g., a packer, and the fracturing fluid may be pumped via one or more stimulation service pumps 22 into the zone of interest 14 via an internal flow path 21 inside the tubing 20 , via a flow path 23 in the annular space between the outer wall of tubing 20 and the inside wall of the wellbore 10 , or via both. The fracturing fluid may contain proppants or sand. A fracturing effect 26 is represented by an ellipse. During the course of the fracturing, or other wellbore service job, the sensors 18 collect data on conditions in the wellbore 10 . Hanging off of the bridge plug 16 or sealable member 19 , the sensors 18 are out of the flow of fracturing fluid and hence are not subject to possibly damaging ablation which may occur if proppants are employed.
[0031] In the third wellbore service configuration in FIG. 1 c , the tubing has been run back into the wellbore 10 , the tubing 20 has been reattached to the bridge plug 16 , the bridge plug 16 has been disengaged from the wellbore casing, and the tubing 20 is shown withdrawing the first tool string 8 from the wellbore 10 . Alternatively, prior to withdrawing the tool string from the wellbore, the tool string may be redeployed and the treatment steps repeated to fracture multiple zones or intervals. For example, as shown in FIGS. 1 h and 1 i , multiple zones or intervals 14 a and 14 b within the wellbore 10 may be fractured. While two zones are show in FIGS. 1 h and 1 i , it should be understood that more than two zones may be treated in a multi-stage job, and preferably the zones are perforated sequentially starting at the bottom zone and working upward. As shown in FIG. 1 h the downhole tool is run into the wellbore via tubing 20 and the sealing member 19 , e.g., a packer, is set. An array of sensors 18 a - d is tethered to and hangs from the bottom of packer. If not already present, perforations 25 are formed by a perforating component of the downhole tool, for example a hydra-jetting tool or a perforating gun. A treatment fluid such as a fracturing fluid may be pumped, for example via the annular flow path 23 , the flow path 21 inside the tubing, or both, though the perforations 25 and into the formation, thereby creating a fracturing effect 26 . Upon completion of the fracturing, for example as determined via data provided by the sensor array 18 a - d , the packer may be repositioned and reset and additional zones may be treated as shown in FIG. 1 i.
[0032] When the first tool string 8 is removed from the wellbore 10 , the sensors 18 may be operably coupled to a monitoring computer to download the data collected by the sensors 18 during the wellbore service job. The sensor data may be analyzed to model the effect of the fracture job and to adjust fracturing parameters for future fracture jobs in similar lithology. The co-deployment and co-retrieval of the bridge plug 16 and the sensors 18 saves extra trips into the wellbore 10 to deploy and retract the sensors 18 .
[0033] Turning now to FIG. 1 d , a second tool string 101 is shown comprising a packer 102 , a tool body 104 , a plurality of jets 106 , the bridge plug 16 , and the plurality of sensors 18 in a fourth wellbore service configuration 100 a . The second tool string 101 may be generically referred to as a downhole tool. The packer 102 seals between two areas of the wellbore 10 and contains a valve or conduit therethrough that permits fluid flow in one direction, as shown with arrows, when desirable. The packer 102 may be referred to as a sealable member. The jets 106 are a plurality of orifices in the tool body 104 wherefrom fracturing fluid flows under pressure. In some embodiments, the jets 106 may be inserts which are formed of special materials that resist erosion. The second tool string 101 is attached to the tubing 20 via a connector 108 . The second tool string 101 is shown after having placed the bridge plug 16 to seal a lower boundary of the zone of interest 14 , having disconnected from the bridge plug 16 , having withdrawn from the bridge plug 16 , and having placed the packer 102 to seal an upper boundary of the zone of interest 14 . The use of the packer 102 and the bridge plug 16 confines the fracture fluid and pressure to the region between the packer 102 and the bridge plug 16 , which may be useful when fracturing a wellbore 10 having multiple zones of interest 14 and/or multiple sets of perforations.
[0034] A fracturing job is shown in progress, with fracturing fluid, which may contain proppants, being pumped down the tubing 20 , through the tool body 104 , out of the jets 106 , into the zone of interest 14 . The sensors 18 hang down from the packer 102 , out of the path of fracturing fluid flow, for example as shown in FIGS. 2 a and 2 b . In an embodiment, the sensors 18 may attach themselves to the wellbore wall as in FIG. 2 b , for example tiltmeters using magnetism to attach to a wellbore casing wall. In an embodiment according to FIG. 3 , the data recovery component 60 may be employed to provide electrical power to and receive data from the sensors 18 and may be located above the packer 102 .
[0035] Turning now to FIG. 1 e , a third tool string 120 is shown comprising the packer 102 , the tool body 104 , the jets 106 , the bridge plug 16 , and the plurality of sensors 18 in a fifth wellbore service configuration 100 b . The third tool string 120 may be generically referred to as a downhole tool. The third tool string 120 is attached to the tubing 20 via the connector 108 . The third tool string 120 is shown after having placed the bridge plug 16 to seal a lower boundary of the zone of interest 14 , having disconnected from the bridge plug 16 , having withdrawn from the bridge plug 16 , and having placed the packer 102 to seal an upper boundary of the zone of interest 14 . The use of the packer 102 and the bridge plug 16 confines the fracture fluid and pressure to the region between the packer 102 and the bridge plug 16 , which may be useful when fracturing a wellbore 10 having multiple zones of interest 14 and/or multiple sets of perforations.
[0036] A fracturing job is shown in progress, with fracturing fluid, which may contain proppants, being pumped down the tubing 20 , through the tool body 104 , out of the jets 106 , into the zone of interest 14 . The sensors 18 hang above the packer 102 , out of the path of fracturing fluid flow, suspended in the wellbore fluid due to buoyancy or through the action of a propulsion action. In an embodiment, the sensors may attach themselves to the wellbore wall as in FIG. 2 b , for example tiltmeters using magnetism to attach to a wellbore casing wall. In an embodiment according to FIG. 3 , the data recovery component 60 may be employed to provide electrical power to and receive data from the sensors 18 and may be located above the packer 102 .
[0037] Turning now to FIG. 1 f , a fourth tool string 140 is shown comprising the packer 102 , the tool body 104 , the jets 106 , the bridge plug 16 , and the sensors 18 in a sixth wellbore service configuration 100 c . The fourth tool string 140 may be generically referred to as a downhole tool. The fourth tool string 140 is attached to the tubing 20 via the connector 108 . The fourth tool string 140 is shown after having placed the bridge plug 16 to seal a lower boundary of the zone of interest 14 and having placed the packer 102 to seal an upper boundary of the zone of interest 14 . The use of the packer 102 and the bridge plug 16 confines the fracture fluid and pressure to the region between the packer 102 and the bridge plug 16 , which may be useful when fracturing a wellbore 10 having multiple zones of interest 14 and/or multiple sets of perforations.
[0038] A fracturing job is shown in progress, with fracturing fluid, which may contain proppants, being pumped down the tubing 20 , through the tool body 104 , out of the jets 106 , into the zone of interest 14 . The sensors 18 hang below the bridge plug 16 , out of the path of fracturing fluid flow, for example as shown in FIGS. 2 a and 2 b . In an embodiment, the sensors may attach themselves to the wellbore wall as in FIG. 2 b , for example tiltmeters using magnetism to attach to a wellbore casing wall. In an embodiment according to FIG. 3 , the data recovery component 60 may be employed to provide electrical power to and receive data from the sensors 18 and may be located below the bridge plug 16 .
[0039] Turning now to FIG. 1 g , a fifth tool string 160 is shown comprising the packer 102 , the tool body 104 , the jets 106 , the bridge plug 16 , and the sensors 18 in a seventh wellbore service configuration 100 d . The fifth tool string 160 may be generically referred to as a downhole tool. The fifth tool string 160 is attached to the tubing 20 via the connector 108 . The fifth tool string 160 is shown after having placed the bridge plug 16 to seal a lower boundary of the zone of interest 14 , having disconnected from the bridge plug 16 , having withdrawn from the bridge plug 16 , and having placed the packer 102 to seal an upper boundary of the zone of interest 14 . The use of the packer 102 and the bridge plug 16 confines the fracture fluid and pressure to the region between the packer 102 and the bridge plug 16 , which may be useful when fracturing a wellbore 10 having multiple zones of interest 14 and/or multiple sets of perforations.
[0040] A fracturing job is shown in progress, with fracturing fluid, which may contain proppants, being pumped down the tubing 20 , through the tool body 104 , out of the jets 106 , into the zone of interest 14 . The sensors 18 hang below the bridge plug 16 , out of the path of fracturing fluid flow, for example as shown in FIGS. 2 a and 2 b . In an embodiment, the sensors may attach themselves to the wellbore wall as in FIG. 2 b , for example tiltmeters using magnetism to attach to a wellbore casing wall. In an embodiment according to FIG. 3 , the data recovery component 60 may be employed to provide electrical power to and receive data from the sensors 18 and may be located below the bridge plug 16 .
[0041] Each of the tool strings may be referred to generally as a downhole tool. While the exemplary wellbore service jobs described above referred to using a bridge plug 16 and a packer 102 in various tool string configurations, those skilled in the art will readily appreciate that other sealable members may be employed to conduct fracturing wellbore service jobs as well as other wellbore service jobs. Other dispositions of the sensors 18 out of the flow of fracture fluid are also contemplated by this disclosure.
[0042] Turning now to FIG. 2 a , the first tool string 8 is shown in the wellbore 10 with six tiltmeters (or other appropriate sensors)—a first tiltmeter 50 a , a second tiltmeter 50 b , a third tiltmeter 50 c , a fourth tiltmeter 50 d , a fifth tiltmeter 50 e , and a sixth tiltmeter 50 f -attached to and hanging below the bridge plug 16 , not attached to the wellbore 10 . The first tiltmeter 50 a is attached to the bridge plug 16 by a first link 52 a . The second tiltmeter 50 b is attached to the first tiltmeter 50 a by second link 52 b . The third tiltmeter 50 c is attached to the second tiltmeter 50 b by a third link 52 c . The fourth tiltmeter 50 d is attached to the third tiltmeter 50 c by a fourth link 52 d . The fifth tiltmeter 50 e is attached to the fourth tiltmeter 50 d by a fifth link 52 e . The sixth tiltmeter 50 f is attached to the fifth tiltmeter 50 e by a sixth link 52 f.
[0043] Turning now to FIG. 2 b , the wellbore 10 is shown with the tiltmeters 50 a - f attached to the wellbore casing and with desirable slack in each of the links 52 a - f . The slack in each of the links 52 a - f mechanically isolates the tiltmeters 50 a - f from one another and from the bridge plug 16 . The slack may be imparted to the links 52 a - f by performing a maneuver wherein the bridge plug 16 is lowered more quickly than the tiltmeters 50 a - f can fall in suspension in the fluid in the wellbore 10 , the tiltmeters 50 a - f are attached to the wellbore 10 , and the bridge plug 16 deploys and seals the wellbore 10 . The tiltmeters 50 a - f may be designed to deploy a drag structure and/or to increase their buoyancy whereby to slow the descent of the tiltmeters 50 a - f in the fluid in the wellbore 10 . The drag structure also may be employed to orient the tiltmeters 50 a - f and to steer them towards the wellbore casing where the tiltmeters 50 a - f may attach to the wellbore casing, for example employing magnets.
[0000] In another embodiment, the tiltmeters 50 a - f may hang in tension, suspended by the links 52 a - f and simultaneously attached to the wellbore casing without slack in the links.
[0044] The links 52 a - f may be chain links; rope wire, or cable tethers; bands, or data transmission cables formed of metal, plastic, rubber, ceramic, composite materials, or other materials known to those skilled in the art. The sensors 50 a - f may separate the links 52 a - f , forming part of the weight bearing structure supporting sensors located below. Alternately, the links 52 a - f may form a continuous chain or tether, and sensors 50 a - f may be attached thereto without forming part of the weight bearing structure. The links 52 a - f may also serve as data communication pathways between the sensors 50 a - f and a memory module 60 , as in FIG. 3 a.
[0045] The discussion of how the sensors 50 a - f are suspended from the bridge plug 16 and attached to the wellbore casing also applies to the alternative tool strings illustrated in FIGS. 1 d - i.
[0046] Turning now to FIG. 3 a , in some embodiments of the first tool string 8 a data recovery component 60 may attached as shown to the bottom of the bridge plug 16 . The data recovery component 60 comprises a battery 62 and a memory tool 64 . The battery 62 provides electrical power via a first cable 66 a to the first sensor 18 a . The memory tool 64 communicates with and receives data from the first sensor 18 a through the first cable 66 a and stores this data, to be downloaded by a monitoring computer at the surface when the first tool string 8 is withdrawn from the wellbore 10 . In some embodiments, the memory tool 64 may provide data collection commands, data collection timing signals, and or excitation signals to the sensors 18 through the first cable 66 a.
[0047] The memory tool 64 may be a data recording device such as for example a microcontroller/microprocessor associated with a memory and operable to receive and store data from the sensors 18 . Electrical power is provided to and data is returned from each of the sensors 18 through a path comprising the first cable 66 a , the first sensor 18 a , a second cable 66 b attached between the first sensor 18 a and the second sensor 18 b , the second sensor 18 b , a third cable 66 c attached between the second sensor 18 b and the third sensor 18 c , the third sensor 18 c , a fourth cable 66 d attached between the third sensor 18 c and the fourth sensor 18 d , and the fourth sensor 18 d.
[0048] A first chain 68 a is shown supporting the weight of the sensors 18 . The first chain 68 a is shown attached to the data recovery component 60 , but in some embodiments the first chain 68 a may attach to the bridge plug 16 . A second chain 68 b , a third chain 68 c (not shown), and a fourth chain 68 d (not shown) are interconnected through the bodies of the sensors 18 and support the weight of the sensors 18 . In an alternate embodiment as shown in FIG. 3 b , the chains 68 attach to each other to form a continuous chain and the sensors attach thereto via attachment 69 without bearing any of the weight. The chains 68 may be constructed of metal, plastic, ceramic, or other materials. Support linkages other than chain also are contemplated, such as a flexible chord.
[0049] In some embodiments, the cable 66 and the chain 68 attached to each sensor 18 may attach directly to the data recovery component 60 . In an embodiment, the cable 66 may be a continuous cable with Tee-like drop connections provided along the length of the continuous cable for coupling to the sensors 18 . In some embodiments the cable 66 and the chain 68 may be enclosed in a sheath to prevent entanglements and to protect the cable 66 and chain 68 from hazards in the wellbore 10 . The cable 66 may be interwoven in the chain 68 . In an embodiment, the cable 66 may be integrated with the chain 68 or a tether.
[0050] The discussion of the data recovery component 60 also applies to the alternative tool strings illustrated in FIGS. 1 d - i.
[0051] In some embodiments, a communication path may be provided between the surface and the downhole tool 16 and/or the sensors 18 . The communication path may be contained by the tubing, for example provided by a cable inside or embedded in the walls of the tubing 20 . In addition to or alternatively, the communication path may be provided by a wireless link such as radio link, an optical link, and/or an acoustic link through the fluid in the wellbore 10 .
[0052] A communication path between the surface and the second tool string 101 , the third tool string 120 , and the fourth tool string 140 , for example through a cable inside or embedded in the walls of the tubing 20 to a monitoring computer located at the surface, may be provided by the tubing 20 . This capability, which may be termed a real-time fracture monitoring capability or near real-time fracture monitoring capability, could be employed to monitor a wellbore servicing operation such as detecting pumping of fracturing fluid into a water bearing formation. Pumping fracturing fluid into a water bearing formation increases flow of water, which is generally not desirable. Being able to detect this event permits stopping the fracturing job and minimizing the fracturing of the water bearing formation. Additionally, this real-time or near real-time fracture monitoring capability may be employed to adaptively control the fracture job, such as stopping pumping of fracturing fluid after data from the sensors 18 fed into a fracture model generated by the monitoring computer indicates an optimal fracture stage has been arrived at.
[0053] In an embodiment, an acoustic communication link between the surface and the first tool string 8 , such as using hydraulic telemetry, may be established. This communication link may be used to monitor fracturing processes while fracturing is in progress as described above.
[0054] In one embodiment, a communication path between the surface and the fifth tool string 160 by providing a connectionless communication link between the bridge plug 16 and the packer 102 and by providing a connected communication link, for example a wire cable within the tubing 20 , from the packer 102 to the surface. The connectionless communication link may be provided by a radio link, an optical link, or an acoustic link, such as using hydraulic telemetry, through the fluid between the bridge plug 16 and the packer 102 . The communication path between the bridge plug 16 and the surface may support the ability to monitor fracturing processes while fracturing is in progress as described above.
[0055] In other embodiments, a combination of these communication link technologies may be employed to provide the ability to monitor fracturing processes or other wellbore service operations in real-time or near real-time.
[0056] Turning now to FIG. 4 , a flow chart is shown of a first method for using the various tool strings of the present disclosure such as shown in FIGS. 1 a - c . The first method begins at block 200 where a sealing member such as the bridge plug 16 or a packer, the sensors 18 , and the tubing 20 are co-deployed downhole. The first method proceeds to block 202 where the bridge plug 16 is seated in the wellbore casing and seals the wellbore 10 below the bridge plug 16 from the wellbore 10 above the bridge plug 16 . The first method proceeds to block 204 where the tubing 20 detaches from the bridge plug 16 . The first method proceeds to block 206 where the tubing 20 is retracted from the wellbore 10 .
[0057] The first method proceeds to block 208 where a wellbore service procedure such as a fracturing job is conducted. This involves pumping fracturing fluid down the wellbore 10 at the appropriate pressure, temperature, and flow rate with the appropriate mix of materials, such as proppants and fluids. The parameters for a specific fracturing job are engineered for a specific lithology or field based on experience and data obtained during previous fracture jobs, as is well known to those skilled in the art. Upon completion of pumping, the first method proceeds to block 210 where the tubing 20 is deployed into the wellbore 10 and reattaches to the bridge plug 16 .
[0058] The first method proceeds to block 212 where the bridge plug 16 detaches from the wellbore casing. The first method proceeds to block 214 where the tubing 20 is retracted from the wellbore 10 , drawing out with it the bridge plug 16 and the sensors 18 .
[0059] The first method proceeds to block 216 where the data collected by the sensors 18 is downloaded to a first computer system. The first method proceeds to block 218 where the data downloaded from the sensors is employed to characterize the fracture job by modeling on a second computer system. This first and second computer systems may be the same computer, or they may be different computers. The characterization of the fracture job of block 218 may occur at the location of the wellbore 10 or it may occur away from the location of the wellbore 10 , for example at a headquarters or at an office.
[0060] Observe that the first method described above saves extra trips into the wellbore 10 to deploy and retrieve the sensors 18 , for example using a wireline equipment. In the first method the sensors 18 are co-deployed and co-retracted with the bridge plug 16 .
[0061] Turning now to FIG. 5 , a flow chart is shown of a second method for using the various tool strings of the present disclosure such as is shown in FIGS. 1 h and 1 i . The second method is related to the first method but is different by providing fracturing of multiple zones within the wellbore 10 . The second method begins at block 220 where a sealing member such as the bridge plug 16 or a packer, the sensors 18 , and the tubing 20 are co-deployed downhole. The second method proceeds to block 221 where the bridge plug 16 is seated in the wellbore casing and seals the wellbore 10 below the bridge plug 16 from the wellbore 10 above the bridge plug 16 ; where the tubing 20 detaches from the bridge plug 16 ; and where the tubing 20 is retracted from the wellbore 10 .
[0062] The first method proceeds to block 222 where a wellbore service procedure such as a fracturing job is conducted. This involves pumping fracturing fluid down the wellbore 10 at the appropriate pressure, temperature, and flow rate with the appropriate mix of materials, such as proppants and fluids. The parameters for a specific fracturing job are engineered for a specific lithology or field based on experience and data obtained during previous fracture jobs, as is well known to those skilled in the art. Upon completion of pumping, the second method proceeds to block 223 where the tubing 20 is deployed into the wellbore 10 , the tubing 20 reattaches to the bridge plug 16 , and the bridge plug 16 detaches from the wellbore casing.
[0063] The second method proceeds to block 224 where if another zone of the wellbore 10 remains to be fractured, the second method proceeds to block 225 . In block 225 the bridge plug 16 and sensors 18 are repositioned to fracture the next zone of the wellbore 10 , for example at a position further out of the wellbore 10 . The second method proceeds to block 221 . By repeatedly looping through blocks 221 , 222 , 223 , 224 , and 225 multiple zones of the wellbore 10 may be fractured. Note that the sensors 18 attached to the bridge plug 16 are not deployed into and retracted from the wellbore 10 between each of the fracturing operations, thus saving numerous extra trips into and out of the wellbore 10 . The sensors 18 detect, collect, and store data for each of the multiple fracturing operations.
[0064] In block 224 if no additional zones of the wellbore 10 remain to be fractured, the second method proceeds to block 226 where the tubing 20 is retracted from the wellbore 10 , drawing out with it the bridge plug 16 and the sensors 18 .
[0065] The second method proceeds to block 227 where the data collected by the sensors 18 is downloaded to a first computer system. The second method proceeds to block 228 where the data downloaded from the sensors is employed to characterize the multiple fracture jobs by modeling on a second computer system. This first and second computer systems may be the same computer, or they may be different computers. The characterization of the fracture job of block 228 may occur at the location of the wellbore 10 or it may occur away from the location of the wellbore 10 , for example at a headquarters or at an office.
[0066] Observe that the second method described above saves multiple extra trips into the wellbore 10 to deploy and retrieve the sensors 18 , for example using wireline equipment. In the second method the sensors 18 are co-deployed and co-retracted with the bridge plug 16 .
[0067] Turning now to FIG. 6 , a flow chart is shown of a third method for using the various tool strings of the present disclosure such as second tool string 101 , the third tool string 120 , the fourth tool string 140 , or the fifth tool string 160 . The third method begins at block 230 where a sealing member such as the bridge plug 16 or a packer, the sensors 18 , the first tool string 101 , and the tubing 20 are deployed into the wellbore 10 . The third method proceeds to block 232 where the bridge plug 16 is seated in the wellbore casing and seals the wellbore 10 below the bridge plug 16 from the wellbore 10 above the bridge plug 16 .
[0068] The third method proceeds to block 234 where a fracturing job is started. This involves pumping fracturing fluid down the wellbore 10 at the appropriate pressure, temperature, and flow rate with the appropriate mix of materials, such as proppants and fluids, as is well known to those skilled in the art.
[0069] The third method proceeds to block 236 where the sensors 18 are monitored at the surface by a first computer system. The monitoring includes gathering data from each of the sensors 18 and analyzing the gathered data. Analysis may include feeding the gathered data into a fracture model which predicts fracture progress based on a history of sensor data. The results of the analyzing the gathered data provides input to fracture job operators making a decision to continue pumping fracturing fluid, to stop pumping fracturing fluid, and perhaps to change the material mix of the fracturing fluid or other fracture job parameters such as pressure, temperature, and flow rate.
[0070] In an embodiment, in block 236 the pumping of fracturing fluid into the wellbore is completely ceased. Substantial vibration may be produced in the wellbore by the pumping of fracturing fluid, and this vibration may interfere with the sensors 18 monitoring the progress of the fracturing job. In another embodiment, in block 236 the pumping of fracturing fluid continues.
[0071] The third method proceeds to block 238 where if the fracturing fluid is not being pumped into a water bearing formation the third method proceeds to block 240 . In block 240 , if the fracture job is not complete, the third method returns to block 234 and the fracture job continues.
[0072] If in block 238 the fracturing fluid is being pumped into a water bearing formation the third method proceeds to block 242 . Similarly, if in block 240 the fracturing job is complete the third method proceeds to block 242 . In block 242 the pumping of fracturing fluid is stopped. The third method proceeds to block 244 where the bridge plug 16 detaches from the wellbore casing, and the tubing 20 is retracted from the wellbore 10 , drawing out with it the first tool string 101 , the bridge plug 16 , and the sensors 18 .
[0073] Observe that the third method described above saves extra trips into the wellbore 10 to deploy and retrieve the sensors 18 , for example using wireline equipment. In the third method the sensors 18 are co-deployed with the first tool string 101 or with the bridge plug 16 and co-retracted with the first tool string 101 or with the bridge plug 16 . Additionally, the third method permits on-location adaptation of fracture job plans to better accord with the circumstances detected, in real-time or near real-time, by the sensors 18 .
[0074] While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein, but may be modified within the scope of the appended claims along with their full scope of equivalents. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented.
[0075] Also, techniques, systems, subsystems and methods described and illustrated in the various embodiments as discreet or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown as directly coupled or communicating with each other may be coupled through some interface or device, such that the items may no longer be considered directly coupled to each but may still be indirectly coupled and in communication with one another. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.
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A system for monitoring a wellbore service treatment, comprising a downhole tool operable to perform the wellbore service treatment; a conveyance connected to the downhole tool for moving the downhole tool in the wellbore, and a plurality of sensors operable to provide one or more wellbore indications and attached to the downhole tool or a component thereof via one or more tethers. A method of monitoring a wellbore service treatment, comprising conveying into a wellbore a downhole tool operable to perform the wellbore service treatment and a plurality of sensors operable to provide one or more wellbore indications attached to the downhole tool or a component thereof via one or more tethers, deploying the downhole tool at a first position in the wellbore for service, treating the wellbore at the first position; and monitoring an at least one wellbore indication provided by the wellbore sensors at the first position.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention provides a surgical prosthesis for facial augmentation and more particularly a modular implantable prosthesis having a variable thickness and contour.
2. Description of Prior Art
The skeletal framework of the face determines many of the relationships between features of the face which will produce either an attractive or unattractive appearance. Prominences or weaknesses in features are related to the underlying bony structure in the face. It is possible to augment weaknesses of the skeletal framework using facial implants to enhance or create prominences. In addition, although not pertinent to the instant invention, it is possible to sculpt the appearance of the face by reducing the projection of underlying bone in areas that are not ideal. Facial implants offer a means of improving the foundation of an unattractive face. By the use of such implants it is possible to convert concavities to convexities, create more of an oval-shaped face by enhancing the prominence of certain areas of the face, and generally improve the overall aesthetic appearance.
The most commonly used facial implant is the chin implant. The second most commonly used facial implant is the malar or cheek implant. The sub-malar and mid-facial implant are also frequently used, and, less frequently, implants augmenting the temple and forehead are employed. Among the newest are supraorbital and mandibular augmentation implants. Many other implants and techniques of skeletal augmentation are known and commonly used by the plastic surgeon. A summary of such procedures is set forth, for example, in AESTHETIC FACIAL SURGERY (Raven Press, 1991) authored by the present inventor.
Malar implants are well known in the art. An example is provided by the present inventor in the ARCHIVES OF OTOLARYNGOLOGY, Vol. 108, pp 441-444, (July, 1982) and in U.S. Pat. No. 4,790,849 issued Dec. 13, 1988 to Terino. The foregoing references generally describe an anatomical implant suitable for positioning between the malar zygomatic bone complex and the fleshy portion of the side of the face commonly referred to as the cheek for increasing the prominence of the cheek below the eye orbit of the patient. Such an implant will raise the cheeks giving the underlying cheekbones a more prominent appearance and imparting a more handsome and pleasing appearance to the facial features of the patient. Such implants are commercially available and are sold in a variety of sizes for a particular shape. In accordance with current practice, once a shape is selected, the surgeon must search through the inventory of existing sizes to find the best fit for a particular patient. In some instances more than one implant may be required to augment different portions of the facial skeleton during a procedure. Such a selection is usually a compromise and does not provide an exact fit. It is, therefore, desirable to provide a single modular implant having the flexibility to be adapted to fit and anatomically conform to the underlying bone structure of any particular patient to provide a desired elevation of the overlying tissue.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an implantable modular prosthesis which, in combination, can be assembled from component parts to produce a composite prosthesis adapted to a particular patient.
It is yet another object of this invention to provide a modular facial implant which consists of a shell, or primary outermost surface, generally anatomically adapted to the host site, and one or more shims adapted to attach to the shell to build up portions thereof to enhance the projection of the overlying tissue and to conform to .the contour of the underlying skeletal structure of the face.
It is yet another object of this invention to provide a modular implantable prosthesis whereby the prosthesis may be assembled from component parts to more particularly take on the desired contour of the face prior to implantation.
Another object of the invention is to provide a modular implantable prosthesis which may be modified following implantation to adjust the projection of the overlying tissue in relation to the underlying skeletal structure.
These and other objects of the invention will become apparent as we turn now to the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a malar implant according to the prior art.
FIG. 2 is a perspective view of the universal shell portion of a modular malar implant in accordance with a preferred embodiment of the present invention.
FIG. 3 is a perspective view of a generalized shim sheet which may be cut to form a shim as shown in phantom.
FIG. 4(a) is a side view of the universal shell of FIG. 2 and the shim of FIG. 3 brought together so as to form a composite implant.
FIG. 4(b) is the same as FIG. 4(a), but shows examples of various expansion types of locking means on the end of the attachment protuberances.
FIG. 5 is a perspective view (a) and end-on view (b) of the shim and implant composite with the connecting tabs cut off to conform to the outer surface of the individual shell.
FIG. 6 is a perspective view of an embodiment of the modular facial implant properly positioned below the patients orbit with it's position slightly below the orbital notch avoiding the infraorbital foramen.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the present invention is best taught by means of an example drawn from the prior art, the invention is understood to not be limited to any particular implant or to any particular embodiment selected for exemplary purposes from the prior art. Turning now to FIG. 1, an embodiment of a malar implant according to the prior art is illustrated. The implant 10, while it may of uniform thickness, generally has a 3-dimensional asymmetric configuration. There is an outer or skin-facing surface 11, illustrated as a generally convex surface having a area of greatest prominence at the apex at the lower mid region of the outer surface 11. The outer surface 11 forms a prominent cheekbone when the implant 10 is implanted in the patient. Fenestrations 12 extending from the outer surface 11 to the inner surface provide channels for tissue ingrowth which stabilizes the implant.
The inner surface is a generally concave surface or deep recess in the back side of the implant which forms a complementary fit with the skeletal tissue underlying the cheek of the patient. Such an implant is generally referred to as an anatomical implant. The cheekbone region includes the maxillary zygomatic bones which form the maxillary zygomatic complex. The cheekbone is the prominence below the eye formed by the zygomatic prong. The malar bone is a four-pointed bone on each side of the face uniting the frontal and superior maxillary bones with the zygomatic process of the maxilla.
It is known in the art that different patients require different shapes and sizes of protheses for building up or augmenting the malar zygomatic complex and/or the submalar area. Thus, the surgeon must have access to an inventory of different sizes and shapes of implants. Prior to surgery, the surgeon must measure the patient to determine which implant is the correct size and shape. Then the correct implant; that is, the implant providing the "best fit" is retrieved from the inventory and, if not already sterile, it is sterilized prior to implantation. As stated earlier, it is common that none of the sizes in the inventory is the exact fit for the particular patient. In such cases, the off-the-shelf implant coming the closest to the ideal is selected.
FIG. 2 shows a universal shell 20 which is a modular component of the implant of the present invention and which may be cut from a sheet of biocompatible elastomer to have a shape approximating the overall shape of, for example, the prior art implant 10. The universal shell 20, which has an upper skin-facing surface 21 and a shim-contacting surface 22, is thinner than the implant 10 because it is meant to be used together with a modular shimming system to build up the shell over the underlying skeletal tissue to approximate the desired overall contour. Thus, the shell 20 may be cut with a pair of scissors or other tool to the correct shape as is required for the particular procedure, and patient. The shim 31 (FIG. 3) may then be cut and positioned against the shim-contacting surface 22 of the universal shell 20 to build a prosthesis having desired projection in specific areas. The shell 20 and shim 31 together form the modular implant of the present invention. In order for the combination or composite modular implant to form a more or less integral structure, means for attaching the shim 31 to the shell 20 are necessary. One such means comprises holes or fenestrations 24 cut in the universal shell 20 to matingly receive protuberances 33 on the shell-contacting surface of a shim 31. In the preferred embodiment, the shim sheet, generally indicated at 30, from which individual shims 31 may be cut, comprises a substantially planar sheet of a biocompatible polymer with protuberances 33 thereon. The protuberances 33 are spaced a distance d apart. The protuberances 33 may have an expansion-type locking means thereon such as a barbed tip 41 or a mushroom tip 42 to securely hold the shim 31 to the shell 20. Holes or fenestrations 24 are then cut in the universal shell 20 such that they can matingly receive the protuberances 33. An actual shim 31, shown in phantom in FIG. 3, may be cut from the shim sheet 30. Shim sheets can be provided in a variety of thicknesses.
In practice, the surgeon may have the patient come in prior to surgery for a fitting. The fitting consists of applying the universal shell 20 to the patient's cheek, cutting it to size and cutting shims 31 to make the overall outer curvature and projection aesthetically pleasing prior to implantation. The shims 31 are cut from the shim sheet 30 and placed on the universal shell. In a preferred embodiment, tissue ingrowth fenestration (not shown) are punched through the prosthesis at the time of surgery. Alternatively, the tissue ingrowth fenestrations are incorporated into the (molded) shell and shim sheets in such a way that when the modular implant is assembled, the tissue ingrowth fenestrations in the shell and shim(s) are in alignment. A mirror image of the prosthesis is made for the other side of the face. Then, sometime prior to surgery, the composite modular implants (prostheses) are sterilized and readied for implantation. Alternatively, sterile shim sheets and shells can be used to assemble a modular implant at the time of surgery.
The manner in which the composite implant comprising the universal shell 20 module and the shim 31 module are assembled into a more or less integral modular implant is shown more clearly in FIGS. 4 and 5. FIG. 4(a) is an end view of a shim 31 having a thickness 32 bearing protuberances 33 on its upper or shell-contacting surface pressed onto the bottom or shim-contacting surface 22 of a universal shell 20 having a thickness 23. The protuberances 33 project above the upper tissue-facing surface 21 of the universal shell 20. As previously stated, the protuberances 33 may have means thereon such as a barb 41 or a mushroom cap 42 to lockingly engage the shell 20. FIG. 5(a)shows the relative positions of the composite shims 31 and the universal shell 20 in the modular prosthesis 50. The shim 31 and shell 20 in the modular prosthesis 50 may be glued together with a medical grade RTV compound such as Silastic® or they may simply be pressed together and held in place by friction. It is most preferable to punch the attachment holes 24 in the universal shell 20 with a coring punch. This removes the material from the universal shell 20 to matingly receive the protuberances 33 in the shim 31. The punch is preferably a multiple-hole punch where the center of the two holes to be punched are separated by a distance d. After the holes 24 are punched in the universal shell 20 and the shim 31 is positioned correctly against the shell 20, then ingrowth fenestrations may be punched in the implant to penetrate both the shim and shell thereby providing space for tissue ingrowth to promote fixation and stabilization of the implant following implantation. These ingrowth fenestrations (not shown) may conveniently be molded into the shim sheet 30 coaxial with and central to the protuberances 33. Such ingrowth fenestrations in the prosthesis are preferably located near the center of the implant so that if it becomes necessary at a later date to remove the implant for further shimming or reduction, the tissue holding the implant in place can be easily snipped. Wherever the fenestrations are located, it is particularly desirable that the tissue ingrowth fenestrations extend from the skin-facing surface of the shell portion through to the tissue-facing surface of the shin portion of the implant.
It is important that the modular prosthesis does not delaminate or otherwise disintegrate following implantation. For example, tissue ingrowth between the shim 31 and the universal shell 20 may force them apart. Thus, the interface between the shim 31 and the universal shell 20 should be designed to discourage organized tissue ingrowth therebetween. One possible way of achieving this may be by making the upper shell-contacting surface of the shim 31 and the bottom shim-contacting surface 22 of the shim 31, which surfaces contact each other in the implant 50, open cell or otherwise disorganized but pervious to tissue ingrowth. Alternately, a silastic adhesive or viscous silicone gel may be used to exclusively fill the interface between the shim and the shell.
While a particular embodiment of the present invention has been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the scope of the invention. For example, the modular nature of the prosthetic implant described herein can be applied to any implantable prosthesis requiring a custom fit to the underlying supportive structure and a particularly desirable projection of the overlying tissue. Chin, temple and forehead implants, for example, as well as any implant adapted to augment an anatomical site may be custom fabricated using the shim and shell type of modular system described herein. In addition to the protuberances discussed above, the means for connecting the shims to the shell may vary. For example, mating "hook-and-loop" type of connectors may be molded into contacting surfaces of the shim sheet and the shell sheet respectively. Or the shim and shell may be joined with adhesive. Or a combination of such means of connection may be employed. It is, therefore, intended to cover in the appended claims all such changes and modifications that are within the scope of the invention.
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A modular prosthesis for implantation beneath the skin is described. The modular prosthesis comprises a universal shell, which is relatively thin and substantially planar, having the general size and shape required for the prosthesis. The prosthesis is a composite structure consisting of the universal shell and one or more shims. The shims are individually cut from a shim sheet of a biocompatible material of suitable thickness. The shim sheet has a shell-contacting surface with means thereon for attaching the shim to the shell. The shims are cut from the shim sheet and attached to the shell to construct a prosthesis providing the desired contour to the overlying tissue following implantation. In a preferred embodiment, the universal shell and the shims have releasable interlocking means therebetween which permits changing the shims or adding shims to the prosthesis as required.
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BRIEF SUMMARY OF THE INVENTION
Corrosion of metal, such as iron (reinforcing steel) embedded in concrete having a surface exposed to moist, saline air is inhibited by removal of a superficial part of the surface of the concrete, preferably by sandblasting or the like, to provide a newly exposed surface and then by promptly spraying forcibly, as by flame-spraying, a molten conductive metal onto the just-exposed surface in order to afford a cover on the concrete. In many instances the reinforcing metal and the covering metal are included in a direct current electric circuit counterbalancing deterioration of the iron.
PRIOR ART
Patents known to the applicant and having some pertinence to this disclosure are as follows:
______________________________________2,866,742 3,766,032 4,196,0643,047,478 3,992,272 4,255,2413,475,304 4,173,523______________________________________
None of the foregoing is particularly concerned with the problem of arranging an evenly distributed nearly perfect (low) electrolytic connection between the reinforcing metal and the coating metal. None is concerned with appropriate steps to provide such a good connection.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a diagrammatic view in cross-section showing an initial sandblasting or surface preparation step.
FIG. 2 is a similar diagrammatic view in cross-section showing the application of an appropriate metallic coating to the just-prepared concrete surface by a stylized "flame-sprayer".
FIG. 3 is a diagram showing in similar cross-section the finished arrangement including a source of electricity.
DETAILED DESCRIPTION
It is a widespread practice to utilize cement concrete for structures. Most of these require reinforcement by included stiff materials strong in tension, such as reinforcing shapes or members almost universally of a ferrous origin, particularly iron or steel bars. The concrete is somewhat pervious to surrounding water and to the atmosphere. Particularly when the surroundings or atmosphere are marine, or otherwise contain saline material, the structure is subject to erosion or corrosion of the metal largely by an electrolytic action. On the short term this may not be serious, but over a long period the integrity of the structure is substantially compromised. It is therefore a great advantage to provide an effective means for reducing or even eliminating the electrolytic action and thus to preserve the integrity of the metal reinforcement and of the whole structure.
In ordinary exposure of the structural concrete, the surface thereof tends to wear away or to be disintegrated by spalling, cracking, dusting and general superficial failure. This aggravates the problem of penetration of corrosive materials to the contained steel (or iron) reinforcing materials.
In accordance with this invention, there is postulated a typical construction embodying a concrete structure 6 of the usual description, including aggregates 7, sand and Portland cement 8 or the like. Such structure encloses a reinforcing shape or bar 9 usually of metal especially of a ferrous material such as steel and has exposed surfaces 11 subject to substantial deterioration, use and wear.
Pursuant to the present invention, the first step in reducing the customary corrosion of the reinforcement 9 is to prepare or to treat the surface 11 by removing the exposed portion thereof. This is variously done, preferably by a sandblast gun 13 ejecting a stream 14 of grit or sand particles or the like against the surface 11. This dislodges and displaces weathered concrete or surface or exposed concrete which has been mechanically abraded or loosened or has disintegrated by atmospheric effects or the like. This first step leaves a surface 16 freshly exposed to the atmosphere and has a roughened, pocked or irregular surface affording what is referred to as "tooth". That is to say, newly exposed surface has depressions or even partly closed pits or a matte finish after the sandblasting has been completed and the sand has been removed. The surface 16 is clean after the sandblasting operation and is fresh in that it has not theretofore been exposed directly to the ambient conditions, especially to the atmosphere.
Promptly following the sandblasting operation and preferably before there has been time for any substantial deterioration in the new surface 16, there is deposited on such new surface a coating or layer 18 of a molten metal. This is often zinc although it can be of some other conductive metal.
The molten or liquified metal is preferably discharged with substantial velocity from a conventional metallizing gun which sprays the metal in finely divided particle form from a nozzle 19 or the like so as to provide a flame deposit. The flame-spray mechanism used is such as to propel and deposit the metallic spray on the just-prepared surface 16 and is directed to afford an evenly distributed layer. The effect is that the finely divided metal in spray form can enter and interengage with all the interstices and pits and depressions in the freshly prepared surface 16. The metal can interlock or interengage therewith with considerable intimacy so that conduction of an electric current between the metal and the adjacent prepared concrete is very good. Even minor currents can easily flow since there is virtually no resistance. The metal 18 can be laid down either as a sheet that is continuous when cool and solid, or in discrete strips or areas adjacent the reinforcement bar 9 or the like.
When the deposition of the metal layer 18 has been completed, the layer is permitted to cool and solidify, any resulting shrinkage assisting in even more tightly interlocking the metal layer and the rough, contacting concrete. To the layer there may then be connected by a conductor 21 a source 22 of direct current also connected by a conductor 23 to the reinforcing bar 9. The aim is to provide a flow of electrical current between the metallic layer 18 and the reinforcing bar 9 by reason of the battery or other direct current source, substantially equal and opposite to the current which would result between the various surface areas of bar 9 and/or other metals or bars electrically connected to bar 9. Since the imposed or impressed current is opposite and equal to the naturally occurring current, the net result is very little or no electrolytic action on the reinforcing bar, which therefore maintains its integrity over a long period.
In some instances it is not necessary to have an external source 22 of direct current because the simple establishment of a metal connection between the surface 16 and the bar 9 is adequate if the surface 18 is composed of a metal which is higher in the electromotive series than the reinforcing metal; although under most circumstances and particularly under severe ambient conditions, the provision of a direct current source is advisable whether by battery or other means, such as a generator.
In various practical instances and in numerous tests, it has been discerned that by first affording a clean, fresh surface 16 by removal of the normally occurring exterior surface 11 to dissipate old material and to leave a pitted, freshly prepared surface, the metal coat or layer is able to unite intimately therewith and to afford a greatly improved electrical continuity.
Although the metal 18 is preferably deposited on the surface 16 to a thickness in the range of 0.010" to 0.030", unusually servere conditions, such as constant exposure to a moist saline environment, may require a thicker coating than 0.030"; and while the metal is customarily laid down as a continuous sheet, some types of reinforced concrete structures are adequately protected by applying the metal in a square gridwork pattern. For example, a gridwork having a band width of 6" and a 6" spacing between the bands has been used to economic advantage.
The process has many applications. Thus, the reinforcing bar 9 in FIGS. 1-3 could be any of the conventional steel reinforcing shapes or it could be a steel wire cable tensioning member in any pre-cast, pre-tensioned concrete structure, such as a girder or beam.
Still other applications in which cathodic protection is afforded by the process include cooling towers and reinforced concrete tanks pre-tensioned by steel bands or wires and coated with a layer of concrete. Quite frequently, oil refineries and chemical plants are located adjacent an arm of the sea in which case corrosive electrolytic forces are present, capable of damaging the numerous concrete-covered, pre-tensioned storage tanks associated with all such installation.
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Electrically conductive metal is melted, preferably by a flame, and is sprayed onto a freshly exposed, pitted surface of a concrete member having iron embedded therein. The sprayed metal, when cooled, forms a metal cover on and interlocked with at least part of the newly exposed surface. The cover and the embedded iron are preferably joined in an electric circuit affording a direct current electromotive force, effectively opposite to that which normally would occur, in order to preclude the deterioration of the contained iron.
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BACKGROUND OF THE INVENTION
The present invention relates to a novel method of dry cleaning of fabric materials and a dry cleaning solvent used therefor. More particularly, the invention relates to a dry cleaning method of fabric materials having advantages of, besides the high cleansing effect exhibited to an oily or greasy dirt deposited on the fabric material and pleasant touch feeling of the fabric material finiashed by the dry cleaning method, absence of unpleasant smell therefrom, little problems against environmental pollution possibly leading to destruction of the ozone layer in the aerosphere and safety against workers' health by virtue of the use of a unique dry cleaning solvent which has never been employed for this purpose of dry cleaning.
Needless to explain, dry cleaning is a process for cleaning a fabric material such as clothes in which the fabric material is immersed in or soaked with a non-aqueous organic solvent capable of dissolving oily or greasy dirt materials deposited on the fabric material so as to dissolve the dirt material out of the fabric material into the solvent followed by removal of the solvent from the cleaned fabric material and drying thereof.
A great variety of organic solvents have been proposed as the dry cleaning solvent and are actually employed for the purpose, of which the solvents currently under wide applications include halogenated hydrocarbon solvents, such as chlorofluorinated hydrocarbons and chlorinated hydrocarbons such as perchloroethylene, trichloroethylene and trichloroethane, and petroleum-based hydrocarbon solvents which are mainly paraffinic or naphthenic.
While advantageous in respects of non-inflammability and rapid drying, the above mentioned halogenated hydrocarbon solvents as a dry cleaning solvent have serious problems because vapors of such a halogenated hydrocarbon solvent emitted to the atmosphere are suspected to be liable for destruction of the ozone layer in the aerosphere in addition to the problem against public and workers' health due to contamination of the underground wate by discarded dry cleaning solvents and environmental pollution by the solvent vapor.
Accordingly, it is now a world-wide trend that use of halogenated hydrocarbon solvents is going to be banned not only as a dry cleaning solvent but also in any other applications. Petroleum-based hydrocarbon solvents are also noxious as an environmental pollutant against workers' health. For example, regulations in many countries prescribe the maximum permissible concentration of vapors of petroleum-based hydrocarbon solvents in the working environment at a very low level in order to ensure workers' health against toxication by the solvents. Among various proposals to solve this problem, Japanese Patent No. 1502875 proposes use of a cyclic organopolysiloxane oligomer or a mixture thereof with a petroleum-based hydrocarbon solvent as a dry cleaning solvent. Japanese Patent Kokai 6-327888 further discloses a method of dry cleaning by using a volatilizable organopolysiloxane having a straightly linear molecular structure as the dry cleaning solvent.
The above mentioned cyclic organopolysiloxane oligomer, however, has a disadvantage, when used as a dry cleaning solvent, that the cyclic organopolysiloxane oligomer is susceptible to ring-opening polymerization by the catalytic activity of the acidic or basic compound contained in the contaminant dirt material deposited on the fabric material for cleaning to produce a non-volatile organopolysiloxane of an increased degree of polymerization which in turn is deposited on the fabric material sometimes adversely affecting the touch feeling of the finished fabric material.
Japanese Patent Kokai 11-214587 teaches that organopolysiloxane oligomers are useful as a washing solvent of articles of a metal, ceramic, glass and plastic as well as semiconductor materials. It is unclear there, however, whether or not the organopolysiloxane oligomer be effective as a dry cleaning solvent for fabric materials or, in particular, clothes.
SUMMARY OF THE INVENTION
In view of the above described problems in the prior art method of dry cleaning, the present invention has an object to provide a novel method for dry cleaning of a fabric material by using a unique volatilizable organopolysiloxane compound as the dry cleaning solvent having advantages, in addition to the excellent cleansing effect on not only oily or greasy dirt materials but also some water-soluble dirt materials and very pleasant touch feeling of the fabric material finished by the method, that the dry cleaning solvent is not toxic against human body to ensure safety to the public and workers' health and that the solvent is not liable for the destruction of the ozone layer in the aerosphere due to emission of the vapor thereof to the atmosphere. The invention also has an object to provide a dry cleaning solvent used in the dry cleaning method.
Thus, the method of the present invention for dry cleaning of a fabric material comprises the steps of:
(a) immersing the fabric material in or soaking the fabric material with a dry cleaning solvent which is a tris(trimethylsiloxy) silane compound represented by the general formula
RSi(—O—SiMe 3 ) 3 , (I)
In which Me is a methyl group and R is a monovalent hydrocarbon group having 1 to 6 carbon atoms, or a mixture thereof with a petroleum-based hydrocarbon solvent so as to dissolve dirt materials on the fabric material into the solvent;
(b) removing the dry cleaning solvent containing the dirt materials dissolved therein from the fabric material by solid-liquid separation; and
(c) drying the fabric material wet with the dry cleaning solvent.
The invention also provides a dry cleaning solvent used in the above defined method of dry cleaning which comprises:, as a uniform mixture:
(A) at least 30% by weight of the tris(trimethylsiloxy) silane compound represented by the above given general formula (I); and
(B) a petroleum-based hydrocarbon solvent in an amount not exceeding 70% by weight.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As is described above, the dry cleaning method of the present invention is characterized by the use of, as the dry cleaning solvent, the tris(trimethylsiloxy) silane compound, referred to as the silicone solvent hereinafter, represented by the general formula (I) or a mixture thereof with a petroleum hydrocarbon solvent.
In the general formula (I) representing the silicone solvent, the group denoted by R is a monovalent hydrocarbon group having 1 to 6 carbon atoms exemplified by alkyl groups such as methyl, ethyl, propyl, butyl, pentyl and hexyl groups, cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl groups and phenyl group, of which alkyl groups having 1 to 3 carbon atoms, i.e. methyl, ethyl and propyl groups, are preferable and methyl group is more preferable as R in respects of the low boiling point to ensure good volatilizability and inexpensiveness of methyl tris(trimethylsiloxy) silane.
Particular examples of the tris(trimethylsiloxy) silane compounds as the silicone solvent include: methyl, ethyl, propyl, butyl, pentyl and hexyl tris(trimethylsiloxy) silanes of the formulas MeSi(—O—SiMe 3 ) 3 , C 2 H 5 Si(—O—SiMe 3 ) 3 , C 3 H 7 Si(—O—SiMe 3 ) 3 , C 4 H 9 Si(—O—SiMe 3 ) 3 , C 5 H 11 Si(—O—SiMe 3 ) 3 and C 6 H 13 Si(—O—SiMe 3 ) 3 , respectively, when R is an alkyl group, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl tris(trimethylsiloxy) silanes expressed by the formulas C 3 H 5 Si(—O—SiMe 3 ) 3 , C 4 H 7 Si(—O—SiMe 3 ) 3 , C 5 H 9 Si(—O—SiMe 3 ) 3 and C 6 H 11 Si(—O—SiMe 3 ) 3 , respectively, when R is a cycloalkyl group, and phenyl tris(trimethylsiloxy) silane of the formula C 6 H 5 Si(—O—SiMe 3 ) 3 , when R is a phenyl group, in which Me is a methyl group. These silicone solvents can be used either singly or as a mixture of two kinds or more.
The above described tris(trimethylsiloxy) silane compound as the silicone solvent can be prepared by several different synthetic routes including, for example, the dehydrochlorination reaction between trimethyl silanol Me 3 SiOH and a trichlorosilane compound RSiCl 3 , a co-hydrolysis/co-condensation reaction between a trichlorosilane compound RSiCl 3 and trimethyl chlorosilane Me 3 SiCl and a rearrangement reaction between hexamethyldisiloxane and a chlorosilane compound or an alkoxysilane compound.
The dry cleaning solvent used in the inventive dry cleaning method of fabric materials can be a mixture of the above described tris(trimethylsiloxy) silane compound and a petroleum-based hydrocarbon solvent which can be any of those used in the conventional dry cleaning processes and specified in JIS K2201-5 and ASTM D235. The petroleum-based hydrocarbon solvent can be paraffinic or naphthenic including benzines and solvent naphthas as well as isoparaffins. These petroleum-based hydrocarbon solvents can be used either singly or as a combination of two kinds or more.
The above described silicone solvent and the petroleum-based hydrocarbon solvent are freely miscible in any desired mixing proportions to give a uniform solvent mixture. When the dry cleaning solvent used in the inventive dry cleaning method is a mixture of the silicone solvent and the petroleum-based hydrocarbon solvent, it is preferable that the solvent mixture contains at least 30% by weight of the silicone solvent, the proportion of the hydrocarbon solvent not exceeding 70% by weight, in order to obtain the advantages to be accomplished by the inventive method. When the weight proportion of the silicone solvent in the solvent mixture is too small, the fabric material finished by dry cleaning by using the mixed solvent cannot be imparted with fully improved touch feeling in addition to the disadvantages inherent in the use of a petroleum-based hydrocarbon solvent.
The procedure of dry cleaning of fabric materials according to the invention is not particularly different from that in the conventional dry cleaning processes using a halogenated hydrocarbon solvent or a petroleum-based hydrocarbon solvent as the dry cleaning solvent excepting for the replacement of the conventional dry cleaning solvent with the silicone solvent or a mixture thereof with a petroleum-based hydrocarbon solvent so that the facilities for dry cleaning ready installed can be used as such in the inventive method. In step (a) of the inventive method, namely, the fabric material for cleaning is immersed in a sufficiently large volume of the dry cleaning solvent so as to dissolve out the dirt materials adhering to the fabric material into the solvent. Instead of immersion in the dry cleaning solvent, the fabric material can be soaked with a limited volume of the solvent, for example, by spraying the solvent. Application of ultrasonic waves to the fabric material or increase of the temperature up to 60° C. or in the range from 10 to 60° C. is sometimes effective to promote dissolution of the dirt materials in the solvent. In step (b) of the inventive method, the fabric material is separated from the solvent containing the dirt material dissolved therein in a solid-liquid separating method such as centrifugation and roller squeezing as completely as possible and, in step (c), the fabric material still wet with the solvent is dried by air drying, hot-air circulation drying or drying under reduced pressure.
In the following, the present invention is described in more detail by way of Examples, which, however, never limit the scope of the invention in any way. The Examples are preceded by the description of the synthetic preparation of the tris(trimethylsiloxy) silane compounds.
SYNTHESIS EXAMPLE 1
Methyl tris(trimethylsiloxy) silane was prepared in the following manner. Thus, 1296 g (8 moles) of hexamethyl disiloxane, 100 g of concentrated hydrochloric acid and 30 g of water were introduced into a four-necked flask of 2 liter capacity to form a reaction mixture which was chilled by immersing the flask in an ice water bath. Thereafter, 359 g (2.4 moles) of methyl trichlorosilane were added dropwise into the reaction mixture under agitation and chilling and agitation of the reaction mixture was continued for further 1 hour to complete the reaction between hexamethyl disiloxane and methyl trichlorosilane. The reaction mixture was then neutralized with a 10% by weight aqueous solution of sodium hydrogencarbonate followed by washing with water and distillation under reduced pressure to give a colorless, clear liquid product having physical properties including: boiling point of 86° C. under 20 Torr, viscosity of 1.4 mm 2 /s at 25° C., density of 0.848 g/cm 3 at 25° C., refractive index of 1.386 at 25° C. and surface tension of 16.6 mN/m at 25° C., from which the liquid product could be identified to be methyl tris(trimethylsiloxy) silane. The yield of the product was 65% of the theoretical value.
SYNTHESIS EXAMPLE 2
Propyl tris(trimethylsiloxy) silane was prepared in the following manner. Thus, 303 g (3 moles) of triethylamine and 300 g of toluene were introduced into a four-necked flask of 2 liter capacity to give a solution which was chilled by immersing the flask in an ice water bath. Thereafter, 177.5 g (1 mole) of propyl trichlorosilane and 297 g (3.3 moles) of trimethyl silanol were added separately but concurrently each dropwise into the solution in the flask under agitation followed by washing with water and distillation under reduced pressure to give a colorless, clear liquid product having physical properties including: boiling point of 78° C. under 12 Torr, viscosity of 2.2 mm 2 /s at 25° C., density of 0.852 g/cm 3 at 25° C., refractive index of 1.395 at 25° C. and surface tension of 17.1 mN/m at 25° C., from which the liquid product could be identified to be propyl tris(trimethylsiloxy) silane. The yield of the product was 55% of the theoretical value.
EXAMPLE 1
Three 15 cm by 15 cm square pieces of plain-woven cloths of polyester, nylon and cotton fibers were each smeared with 1 g of a motorcar oil on the respective center areas to serve as the oil-stained fabric specimens for the dry cleaning test. The thus stained test specimens were put together into 1 liter of methyl tris(trimethylsiloxy) silane prepared in Synthesis Example 1 held in the 3-liter washing vessel of a test washer machine and agitated therein for 15 minutes at 40° C. followed by roller squeezing and drying in a hot-air drying oven at 60° C. taking 60 minutes.
The conditions of each of the test specimens after the above described dry-cleaning run were examined by subjecting the specimens to organoleptic tests for the items of: (Evaluation Item I) cleansing effect on the oil-stained areas; (Evaluation Item II) touch feeling of the finished cloths; and (Evaluation Item III) smell due to remaining solvent. The results of each evaluation item were rated in two ratings of A (no trace of oil stain) and B (trace of oil stain recognizable) for the Evaluation Item I, in two ratings of A (good) and B (poor) for the Evaluation Item II and in three ratings of A (no smell), B (slight but noticeable smell) and C (noticeable smell) for the Evaluation Item III as shown in Table 1 below. Discoloration or denaturation was noted in none of the test specimens after the dry cleaning test.
EXAMPLE 2
The experimental procedure was substantially the same as in Example 1 described above excepting for the replacement of the methyl tris(trimethylsiloxy) silane as the dry cleaning solvent with the same volume of propyl tris(trimethylsiloxy) silane prepared in Synthesis Example 2. The results of the test cleaning are shown in Table 1. Discoloration or denaturation was noted in none of the test specimens after the dry cleaning test.
EXAMPLE 3
The experimental procedure was substantially the same as in Example 1 described above excepting for the replacement of the methyl tris(trimethylsiloxy) silane as the dry cleaning solvent with the same volume of a 50:50 by weight mixture of methyl tris(trimethylsiloxy) silane and a petroleum-based hydrocarbon solvent (Brightsol, a product by Shell Japan Co.). The results of the test cleaning are shown in Table 1. Discoloration or denaturation was noted in none of the test specimens after the dry cleaning test.
COMPARATIVE EXAMPLE 1
The experimental procedure was substantially the same as in Example 1 described above excepting for the replacement of the methyl tris(trimethylsiloxy) silane as the dry cleaning solvent with the same volume of the petroleum-based hydrocarbon solvent (Brightsol, supra) alone. The results of the test cleaning were clearly inferior for the Evaluation Items II and III as shown in Table 1 although no discoloration nor denaturation was noted in any of the test specimens after the dry cleaning test.
TABLE 1
Fiber
Evaluation
Polyester
Nylon
Cotton
Item
I
II
III
I
II
III
I
II
III
Example 1
A
A
A
A
A
A
A
A
A
Example 2
A
A
A
A
A
A
A
A
A
Example 3
A
A
B
A
A
B
A
A
B
Comparative
A
B
C
A
B
C
A
B
C
Example 1
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The invention discloses a novel method for dry cleaning of a fabric material characterized by the use of a unique dry cleaning solvent which is a tris(trimethylsiloxy) silane compound represented by the general formula of RSi(—O—SiMe 3 ) 3 , in which Me is a methyl group and R is a monovalent hydrocarbon group of 1 to 6 carbon atoms or, preferably, a methyl group, or a mixture thereof with a petroleum-based hydrocarbon solvent in a limited proportion. In addition to the excellent effect of dry cleaning equivalent to that of conventional dry cleaning solvents and little unpleasant smell remaining on the fabric material, the solvent used in the inventive method is little liable for the problems of environmental pollution against public and workers' health and the problem of ozone layer destruction in the aerosphere due to emission of vapors of halogenated hydrocarbon solvents can be solved by the inventive method.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a dehumidifier for removing the moisture in the air by heat exchange.
2. Description of the Related Art
Such type of a prior art dehumidifier is disclosed in Japanese Utility Model Publication No. 57-59820, in which a cooling zone is defined by an inner housing and an evaporator accommodated therein. A precooling zone is defined between the inner housing and a cylindrical outer housing in which a heat transfer pipe is accommodated. Both end openings of the outer housing are sealed by covers welded thereto.
Hot end moist air passes through the precooling zone, and thereafter through to the cooling zone. The air passing through the cooling zone is allowed to escape to the outside through the heat transfer pipe. The moisture in the air is removed when it is cooled in the cooling zone, and the dehumidified cool air flows through the heat transfer pipe. Accordingly, the hot and moist air flowing in the precooling zone can be precooled by the cool air in the heat transfer pipe.
The foregoing conventional dehumidifier consists mainly of iron members, and rust is caused by the hot and moist air passing through the dehumidifier. Accordingly, the wall thickness of the dehumidifier must be increased in order to take the rust effect into consideration. This will increase the size and weight of the dehumidifier. There is also a possibility that rust will contaminate the dry air to be discharged.
Both end openings of the outer housing are sealed by the covers which are welded thereto. However, the welding of the covers requires professional staffing, and also the welded products do not usually maintain their initial quality and reliability. Besides, most of the parts inside the outer housing are fixed by welding, so that intricate, laborious and time-consuming welding operations are required to produce the dehumidifier. Further, since the covers are directly welded to the outer housing, the apparatus cannot be easily disassembled to maintain the various components of the dehumidifier.
If the quantity of heat in the incoming hot and moist air is above the heat exchange capacity of the dehumidifier, an additional unit for assisting in cooling the dehumidifier will be required.
SUMMARY OF THE INVENTION
The present invention addresses and resolves the foregoing problems with conventional dehumidifiers. It is a first object of the invention to provide a rust proof, light and compact dehumidifier.
It is a second object of the invention to provide a dehumidifier which can be manufactured and assembled without welding, and which has the capacity to process significant heat transfer.
In order to attain the above objects, the dehumidifier according to the present invention includes a first chamber and a second chamber formed parallel to each other, along the longitudinal direction of the dehumidifier body.
A first cover and a second cover are detachably secured to the ends of the body, to seal the open ends of the first and second chambers, respectively. An evaporator is accommodated in the first chamber. A pipe extends through the second chamber, and divides it into a precooling zone and a reheating zone. The precooling zone corresponds to the internal space of the pipe. The reheating zone corresponds to the space outside the pipe and inside the second chamber. A path connects the outlet of the precooling zone to the inlet of the first chamber, and is defined between the dehumidifier body and the second cover, for feeding the air to the first chamber. A path connects the outlet of the first chamber to the inlet of the reheating zone, and is defined between the body and the first cover, for feeding the air to the reheating zone. The body, covers, evaporator and pipe are made of rust proof material.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of this invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with the objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments, taken in conjunction with the accompanying drawings, in which:
FIG. 1 shows a horizontal cross-sectional view of a dehumidifier according to a first embodiment of the invention;
FIG. 2 shows a partially cutaway perspective view of the dehumidifier shown in FIG. 1;
FIG. 3 is a cross sectional view of the dehumidifier taken along the line III--III of FIG. 1;
FIG. 4 is a cross-sectional view of the dehumidifier taken along the line IV--IV of FIG. 1;
FIG. 5 shows a partially cutaway perspective view of a dehumidifier according to a second embodiment of the invention; and
FIG. 6 is a horizontal cross sectional view of the dehumidifier shown in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the invention will now be described referring to the attached drawings.
As shown in FIGS. 1 to 4, the dehumidifier includes a body 1 which is made of rust proof material, such as aluminum, and has a substantially rectangular cross section. Two elongated bores or openings 1a and 1b, each of which has a circular cross section, are defined in the body 1, in parallel relationship to each other, and extend along the longitudinal axis of the body 1. The first bore 1a constitutes a cooling chamber 2, and the second bore 1b constitutes a part of a reheating chamber 3. Aluminum covers 4 and 5 are detachably fitted to both ends of the body 1 by means of a plurality of hexagonal socket head cap screws. The covers 4 and 5 seal the end openings of the first and second bores 1a and 1b, respectively.
A copper or aluminum refrigerant pipe 7 is inserted in the cooling chamber 2 and penetrates through the cover 4. The free end of the refrigerant pipe 7 is closed and abuts the inner surface of the other cover 5. A seal ring 8 is interposed between the cover 4 and the refrigerant pipe 7 to secure hermetic sealing of the cooling chamber 2. A plurality of closely spaced apart elongated aluminum heat exchange fins 9 extend radially from the outer periphery of the refrigerant pipe 7 to form a high density heat exchange device. A capillary tube 10 is inserted inside the pipe 7, for feeding a refrigerant thereto, in such a way that a free open end of the tube 10 is located adjacent to the closed free end of the refrigerant pipe 7. The refrigerant is supplied from one open end of the capillary tube 10 into the refrigerant pipe 7. The refrigerant pipe 7, heat exchange fins 9 and capillary tube 10 constitute an evaporator 11.
A heat transfer pipe 12 is inserted in the second bore 1b, such that the internal space of the heat transfer pipe 12 constitutes a precooling chamber 13. A middle portion of the heat transfer pipe 12 is spirally waved, with the spiral crests 12a contacting the inner wall surface of the second bore 1b. A plurality of spiral spaces forming the reheating chamber 3, are defined between a spiral troughs 12b of the heat transfer pipe 12 and the inner wall surface of the second bore 1b.
An inlet side end portion (left end portion in FIG. 1) of the heat transfer pipe 12 is fitted into the cover 4 with a seal ring 14 interposed therebetween. Inlets for the heat transfer pipe 12, i.e. air inlets 15 and 15B, communicating with the inlet of the precooling chamber 13, are defined in the cover 4 at one side wall as well as at the top and bottom, respectively. Hermetical sealing between the air inlet side and the reheating chamber side is achieved by the seal ring 14. The air inlets 15B opening to the top and bottom of the cover 4 are normally plugged, and only the air inlet 15A opening to the side wall is normally unplugged. The outlet (the left end opening in FIG. 1) of the cooling chamber 2 and the inlet (the left end opening in FIG. 1) of the reheating chamber 3 are connected by a path 4a defined between the cover 4 and the body 1.
As shown in FIGS. 1 and 4, an annular spacer 17 is fitted around the inner circumference on the outlet side (the right end opening in FIG. 1) of the reheating chamber 3 with a seal ring 16 being interposed therebetween. The outlet side (right end opening in FIG. 1) of the heat transfer pipe 12 is fitted into the spacer 17 via a seal ring 18. A pair of steps 19 is formed on the inner surface of the cover 5, adjacent to the spacer 17 and the heat transfer pipe 12. The steps 19 partially abut the spacer 17 and the heat transfer pipe 12. The outlet of the heat transfer pipe 12, i.e. the outlet of the precooling chamber 13, and the inlet (the right end opening in FIG. 1) of the cooling chamber 2 are connected by a path 5a which is defined between the cover 5 and the body 1. An air outlet 20 is defined in one side wall of the body 1 and communicates with the outlet of the reheating chamber 3. Hermetical sealing between the air outlet side and the outlet side of the precooling chamber 13 is achieved by the seal rings 16 and 18.
As shown in FIGS. 1 and 3, a discharge port 21 communicates with the outlet side of the cooling chamber 2, and is defined at the bottom of the body 1. The evaporator 11 does not include heat exchange fins 9 in an intermediate section that is adjacent to the location of the discharge port 21. Accordingly, the heat exchange fins 9 are divided into two groups on each side of the discharge port 21, i.e. a first fin group 9A on the inlet side and a second fin group 9B on the outlet side of the cooling chamber 2. Steps 22 are formed on the inner wall surface of the cooling chamber 2 at the location of the discharge port 21 so that the cross-sectional area of the cooling chamber 2 is enlarged compared with the other sections. As shown in FIG. 3, a drain trap 24 is connected to the discharge port 21 via a cap 23. The operation of the dehumidifier will now be described in detail.
Hot and humid air is introduced through the air inlet 15A to the precooling chamber 13 defined in the heat transfer pipe 12 and flows rightward (FIG. 1). The air passes through the precooling chamber 13 and is led to the cooling chamber 2 through the space between the steps 19 and the path 5a and then flows leftward between the heat exchange fins 9 (FIG. 1). The air in the cooling chamber 2 is cooled by the evaporator 11, and the moisture in the air is simultaneously removed by the evaporator 11. Accordingly, the hot and humid air is converted into cool and dry air after passing through the cooling chamber 2. The moisture which is removed from the air is discharged through the discharge port 21 and the drain trap 24.
As described above, the moisture in the air flowing through the cooling chamber 2 is removed mostly by the heat exchange action with the first fin group 9A. Since the cross-sectional area of the cooling chamber 2 is enlarged at the intermediate section between the first and second fin groups 9A and 9B, the air flow rate is reduced at this intermediate section. Accordingly, the moisture removed from the air is prevented from being carried by the air flow beyond the discharge port 21 into the reheating chamber 3. The moisture is substantially retained in the intermediate section.
The step 22 serves to make certain that the moisture will be guided through the discharge port 21 to the drain trap 24, without flowing along the inner bottom surface of the cooling chamber and going into the reheating chamber 3. Dust and other impurities remaining in the air after passing through the first fin group 9A are removed by the second fin group 9B.
The cool and dry air, having passed through the cooling chamber 2, is led to the reheating chamber 3 through the path 4a. After flowing spirally along the outer periphery of the heat transfer pipe 12 toward the air outlet 20, the air is discharged from the air outlet 20. Thus, the hot and humid air in the precooling chamber 13 is first precooled by the cool and dry air flowing around the precooling chamber 13 before entering the cooling chamber 2, and the load on the evaporator 11 can be reduced. The cool and dry air passing through the reheating chamber 3 is heated by the hot and humid air introduced to the precooling chamber 13.
In the dehumidifier according to the first embodiment, as described above, the heat transfer pipe 12 has a spirally waved portion. Thus, not only the surface area on the outer circumference of the pipe but also the distance of the path for the cool and dry air can be made greater than in a dehumidifier with a smooth cylindrical pipe having no spirally waved portion. Further, the waved inner wall surface of the heat transfer pipe 12 causes turbulence in the flow of the hot and humid air in the pipe 12. Accordingly, the heat exchange effectiveness in the precooling chamber 13 can be improved to provide a better precooling effect than if the cool and dry air flow and the hot and humid air flow are laminar.
Since the entire apparatus is made of rust proof materials such as aluminum according to the first embodiment of the invention, there is no danger of rusting, and hence the wall thickness need not be made large. This contributes to the reduction in the size and weight of the apparatus. Further, clean air can be processed without rust contamination.
Since the covers 4 and 5 are secured to the body 1 by hexagonal socket head cap screws 6, furthermore, they can be removed easily, allowing easy maintenance of the internal portion of the apparatus. The fitting by the screws 6 does not require skilled labor and, consequently, the products can maintain a substantially fixed high quality of operation and reliability.
According to the first embodiment of the invention, since the body 1 has a cylindrical shape having two bores, the body can be molded by extrusion, and thus the length of the body can easily be changed. Accordingly, when very hot air is to be processed, the heat exchange capacity of the apparatus can be increased merely by elongating the body 1, the cooling chamber 2, the reheating chamber 3 and the other components. In other words, the degree of freedom in the design is high. In this case, the length of the evaporator 11 and that of the heat transfer pipe 12 must be changed depending on the length of the body 1. Since, the evaporator 11 includes a plurality of heat exchange fins 9 that are radially formed on the outer periphery circumference of a linear refrigerant pipe 7, and the heat transfer pipe 12 is linear, the length of these components can be easily changed. Covers 4 and 5 of the same size can be used irrespective of the length of the body 1.
As described above, since both the evaporator 11 and the heat transfer pipe 12 are basically comprised of a linear pipe, their structure is relatively simple and provides high efficiency of space utilization, so that the size of the entire apparatus can be reduced. Besides, the evaporator 11 provides sufficient heat exchange capacity by means of the heat exchange fins 9. The spirally waved portion in the heat transfer pipe 12 also provides sufficient heat exchange capacity. A refrigerant is supplied from the capillary tube 10 and discharged from the refrigerant pipe 7, and the inlet and outlet of the refrigerant are provided on the same side so that supply and discharge of the refrigerant to and from the evaporator 11 can be facilitated.
The evaporator 11 and the heat transfer pipe 12 are not fixed to the body 1. In other words, the evaporator 11 is inserted to the cooling chamber 2 of the body 1 and is designed to pass through the cover 4 so as to be supported partially thereby. The heat transfer pipe 12 is fitted at the inlet side into the cover 4 so as to be supported thereby. The outlet side of the pipe 12 is inserted through the spacer 17 so as to be supported thereby. Accordingly, the evaporator 11 and the heat transfer pipe 12 can easily be detached from the body 1 when the covers 4 and 5 are removed. This makes it easy to assemble, replace and maintain the dehumidifier. Moreover, the seal rings 8, 14, 16 and 18 are disposed respectively at the supporting portions of the evaporator 11 and heat transfer pipe 12 can secure airtightness of the apparatus.
In this embodiment, the drain trap 24 is directly attached to the body 1 with no discharge pipe or the like being interposed therebetween, so that the entire apparatus can be made compact and that there is no fear of having such discharge piper clogged with dust or other impurities.
FIGS. 5 and 6 show another dehumidifier according to a second embodiment of the invention. As shown in FIGS. 5 and 6, two cooling chambers 2 and two reheating chambers 3 may be defined in a body 25, in parallel, with two evaporators 11 and two heat transfer pipes 12 disposed therein. This embodiment employs two sets of the heat exchanger used in the first embodiment.
In this second embodiment, two each of covers 4 and 5, similar to those used in the first embodiment, are secured to each end of the body 25. One of the air inlets 15B is defined in the top and bottom (in the second embodiment the top and bottom turn to side walls) of each cover 4 (which is plugged in the first embodiment) is opened, and the unplugged air inlets 15B of the respective covers 4 are aligned to allow communication therebetween. Further, the air inlet 15A of one cover 4 is opened and that of the other cover 4 is plugged. Hot and humid air introduced from the unplugged air inlet 15A is led to the two precooling chambers 13 through the air inlet 15B.
A throughhole 26 is formed on the outlet side of the two reheating chambers 3 defined in the body 25, and an air outlet 27 communicating with the throughhole 26 is also designed to open to the top surface of the body 25. The air which dehumidified in these two chambers separately is combined at the outlet side of the reheating chambers 3, passes through the throughhole 26, and is discharged from the single air outlet 27.
Accordingly, by preparing a different body 25 of double structure, the dehumidifier can cope with two-fold throughput of air, employing similar parts as those used in the first embodiment.
Although two embodiments of the present invention have been described herein, it should be apparent to those skilled in the art that the present invention may be embodied in many other different forms without departing from the spirit of scope of the invention. For example, it would be possible to use a body 1 or 25 and covers 4 and 5 that are made of synthetic resin materials.
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A dehumidifier includes an elongated body in which a first open ended chamber and a second open ended chamber are defined parallel to each other along the longitudinal direction of the body. A first cover and a second cover are detachably secured to the ends of the body, to cover the open ends of the first and second chambers, respectively. An evaporator is housed in the first chamber. A pipe is disposed in the second chamber, and divides the second chamber into a precooling zone, which corresponds to the internal space of the pipe extending along the axis thereof, and a reheating zone which corresponds to the external space. A path connects the outlet of the precooling zone and the inlet of the first chamber, and is defined between the dehumidifier body and the second cover, for feeding the air from the precooling zone to the first chamber. Another path connects the outlet of the first chamber and the inlet of the reheating zone, and is defined between the body and the first cover, for leading the air from the first chamber to the reheating zone. The body, covers, evaporator and pipe are made of rust proof material.
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BACKGROUND OF THE INVENTION
This invention relates generally to building temperature controls and more specifically to setback thermostats.
In homes with non-automatic setback thermostats, it is normal for the homeowner to set the temperature down at night and up again in the morning. this is done by altering the setpoint of the device. The repeatability of the actual temperature set depends upon the persons visual acuity and manual dexterity. In addition, no indication of the setback is readily apparent.
SUMMARY OF THE INVENTION
The present invention is a thermostat having a simple setback and setup indication. A slide for setting a desired temperature is formed within an assembly used for putting the thermostat into the setup or setback mode. A flange adjacent to the assembly and hidden by the asssembly when the thermostat is in a . normal operating mode, can be colored to contrast with the assembly to provide a visual indication of setup or setback when the assembly is moved.
In a first embodiment, two potentiometers are adjusted by the slide and assembly upon movement of the slide and assembly to adjust the temperature setpoint.
In a second embodiment, two ramps are placed between a temperature sensitive element and a switch. One ramp is continuous while the other ramp has at least two flat regions along one side. By arranging the ramps, the temperature sensitive element and the switch in a desired way, movement of the ramps affects the temperature at which the switch is actuated.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1A is a front perspective view of the exterior of the inventive thermostat in a normal operating mode.
FIG. 1B is a perspective view of the inventive thermostat in a setback mode.
FIG. 1C is a perspective view of the inventive thermsotat in a setup mode.
FIG. 2A is a partial internal view of the first and second temperature setting and adjusting means in an electronic embodiment of the inventive thermostat.
FIG. 2B is a block diagram of the electronic embodiment of the thermostat.
FIG. 3A is a partial internal view of the first and second temperature setting and adjusting means of a mechanical embodiment of the present invention.
FIGS. 3B, 3C and 3D are top views of the mechanical embodiment excluding the temperature setting means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1A, thereshown is the exterior of thermostat 5 of the present invention. The thermostat includes a first temperature setting means 10, second temperature setting means 15, flange 20 and cover 25. The cover may include a temperature scale, setpoint indicator 26 and temperature indicator 27.
The thermostat is capable of turning on a heating or cooling system when the setpoint of the thermostat does not match the temperature sensed by the thermostat in a manner well known in the art. The setpoint is adjusted by moving first temperature setting means 10, which in this case is a slide, in the channel 16 formed in the second temperature setting means 15 until setpoint indicator 26 indicates a desired temperature. More on the operation of the thermostat will be described below.
As was stated before, at night or when the controlled space is to be unoccupied for a long period, it is desirable to reduce the energy used to maintain space temperature. This may be accomplished by lowering the setpoint when in a heating mode (setback) or raising the temperature when in a cooling mode (setup).
The present invention provides a simple to make and simple to use setback or setup indication means as shown in FIGS. 1B and 1C. Second temperature setting means 15 is movable with respect to cover 25 and flange 20 to put the thermostat into either setback or setup mode. As an example, the position of second temperature setting means in FIG. 1B could be indicative of the thermostat being in setback mode. Then, FIG. 1C would be indicative of setup mode. It is obvious however, that these positions could also be reversed and still fall within the spirit of the invention. Flange 20 may be modified at regions 22 and 23 so that these regions when exposed due to movement of second temperature setting means 15 easily indicate whether the thermostat is in setback or setup mode. For example, region 22 could be colored blue to indicate setback while region 23 could be colored red to indicate setup.
While the exterior of the inventive thermostat 5 has been described, more details of the internal operation of the thermostat is provided with reference to FIGS. 2A through 3D.
In FIGS. 2A and 2B, an electronic version of the inventive thermostat is shown. First temperature setting means 10, also known as a slide, moves in channel 16. Slide 10 contacts second temperature adjustment means 35, which in this case is a potentiometer. Movement of the slide causes a change in the resistance of the potentiometer. In this case, serrated edge 12 of slide 10 contacts gear wheel 35 to change the resistance. A linear potentiometer could be used equally as well with some modification to slide 10.
Second temperature setting means 15, also known as an assembly, is connected to second temperature adjustment means 40. The second temperature adjustment means may be a potentiometer. The assembly has a serrated portion 17 which contacts a gear wheel 45 to modify the resistance of the second potentiometer. Again, a linear potentiometer could be used in place of the shown potentiometer with some modifications to assembly 15.
In FIG. 2B, the electrical circuit of the electronic embodiment is shown. A temperature sensing means 50 produces a electrical signal proportional to a sensed temperature and is connected to comparators 60, 65. The two potentiometers are connected in series and then joined to the comparators. Switch 55 determines whether the thermostat is in a heating or cooling mode. The comparators produce a signal depending upon relative signal levels to operate either the furnace or the air conditioner.
Turning now to FIG. 3A, thereshown is a portion of a mechanical embodiment of the present invention in a front perspective view. First temperature setting means (slide) 10' and second temperature setting means (assembly) 15' are the same as in the first embodiment. The slide is connected via first rod 66 to first temperature adjustment means 30', also known as a first ramp. The first ramp 30' has a sloped region 31 extending from first end 32 to second end 33. Movement of slide 10 causes movement of first ramp 30.
Assembly 15' is connected via slide 65 to second temperature adjustment means 40', also known as second ramp. Second ramp 40' has three flat regions 42, 43 and 44 separated by sloped regions 46 and 47. Movement of assembly 15' causes movement of second ramp 40'. Note that the three level second ramp 40' is necessary if a setup and setback are both desired in the same thermostat. Otherwise, only two levels are necessary.
Looking now at FIGS. 3B, 3C and 3D, thereshown is a top view of the second embodiment without the first and second temperature setting means and connecting rods. Wall 8 contains all of the pieces of the thermostat. Temperature sensing means 70 is connected to wall 8 and expands as the temperature rises while contracting when the temperature falls. Temperature sensing means 70 may be a bimetal or a filled element and is connected to second ramp 40, by rod 71. Next, first ramp 30' is slidably connected to second ramp 40'. Lastly, rod 72 connects first ramp 30' to switch 80. Switch 80 is operated by moving actuator 81 axially.
In FIG. 3D, the thermostat is shown in normal operation. Note that second ramp 40' is positioned so that rod 71 rests on the middle level 43 of the second ramp. In FIG. 3B, the thermostat is in setback mode with the second ramp being positioned to be in contact with rod 71 at low level 42. Lastly, in FIG. 3C. second ramp 40' is positioned to be in a setup mode with the second ramp contacting rod 71 at high level 44.
The foregoing has been a description of a novel and non-obvious thermostat. The inventor does not intend to limit the invention to the foregoing description, but instead defines the limits of the invention through the claims appended hereto.
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A thermostat having a simple to see and use setup-setback visual indicator. One temperature control is used to set temperature while a second temperature control is used to activate the setup or setback. The second temperature control is offset from the body of the thermostat in the setup or setback mode to provide simple visual indication of the setup or setback.
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RELATED PATENT APPLICATIONS
[0001] This application is a Continuation-In-Part of prior U.S. patent application Ser. No. 10/868,745, filed Jun. 9, 2004, which was a Continuation-In-Part of prior U.S. patent application Ser. No. 10/307,250, filed Nov. 30, 2002, which was a Continuation-In-Part of prior U.S. patent application Ser. No. 09/566,622, filed May 8, 2000, now U.S. Pat. No. 6,733,636B1 issued May 11, 2004, entitled WATER TREATMENT METHOD FOR HEAVY OIL PRODUCTION, which claimed priority from prior U.S. Provisional Patent Application Ser. No. 60/133,172, filed on May 7, 1999. Also, this application claims priority from U.S. Provisional Patent Application Ser. No. 60/578,810, filed Jun. 9, 2004. The disclosures of each of the above identified patents or patent applications are incorporated herein in their entirety by this reference, including the specification, drawing, and claims of each patent or application.
COPYRIGHT RIGHTS IN THE DRAWING
[0002] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The applicant no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
TECHNICAL FIELD
[0003] The invention disclosed and claimed herein relates to treatment of water to be used for steam generation in operations which utilize steam to recover oil from geological formations. More specifically, this invention relates to novel, improved techniques for efficiently and reliably generating from oil field produced waters, in high pressure steam generators, the necessary steam for down-hole use in heavy oil recovery operations.
BACKGROUND
[0004] Steam generation is necessary in heavy oil recovery operations. This is because in order to recover heavy oil from certain geologic formations, steam is required to increase the mobility of the sought after oil within the formation. In prior art systems, oil producers have often utilized once-through type steam generators (“OTSG's). As generally utilized in the industry, once through steam generators—OTSG's—usually have high blowdown rates, often in the range of from about 20% to about 30% or thereabouts. Such a blowdown rate leads to significant thermal and chemical treatment inefficiencies. Also, once through steam generators are most commonly provided in a configuration and with process parameters so that steam is generated from a feedwater in a single-pass operation through boiler tubes that are heated by gas or oil burners. Typically, such once through steam generators operate at from about 1000 pounds per square inch gauge (psig) to about 1600 psig or so. In some cases, once through steam generators are operated at up to as much as about 1800 psig. Such OTSG's often operate with a feedwater that has from about 2000 mg/L to about 8000 mg/L of total dissolved solids. As noted in FIG. 1 , which depicts the process flow sheet of a typical prior art water treatment system 10 , such a once through steam generator 12 provides a low quality or wet steam, wherein about eighty percent (80%) quality steam is produced. In other words, the 80% quality steam 14 is about 80% vapor, and about 20% liquid, by weight percent. The steam portion, or high pressure steam produced in the steam generators is injected via steam injection wells 16 to fluidize as indicated by reference arrows 18 , along or in combination with other injectants, the heavy oil formation 20 , such as oils in tar sands formations. The injected steam 14 eventually condenses and an oil/water mixture 22 results, and which mixture migrates through the formation 20 as indicated by reference arrows 24 . The oil/water mixture 22 is gathered as indicated by reference arrows 26 by oil/water gathering wells 30 , through which the oil/water mixture is pumped to the surface. Then, the sought-after oil is sent to an oil/water separator 32 in which the oil product 34 separated from the water 35 and recovered for sale. The produced water stream 36 , after separation from the oil, is further de-oiled in a de-oiling process step 40 , normally by addition of a de-oiling polymer 42 or by other appropriate processes. Such a de-oiling process usually results in generation of an undesirable waste oil/solids sludge 44 . However, the de-oiled produced water stream 46 is then further treated for reuse.
[0005] The design and operation of the water treatment plant which treats the de-oiled produced water stream 46 , i.e., downstream of the de-oiling unit 40 and upstream of injection well 16 inlet 48 , is the key to the improvement(s) described herein.
[0006] Most commonly in prior art plants such as plant 10 , the water is sent to the “once-through” steam generators 12 for creation of more steam 14 for oil recovery operations. The treated produced water stream 12 F which is the feed stream for the once through steam generator, at time of feed to the steam generator 12 , is typically required to have less than about 8000 parts per million (“PPM”) of total dissolved solids (“TDS”). Less frequently, the treated produced water stream 12 F may have up to about 12000 parts per million (as CaCO3 equivalent) of total dissolved solids, as noted in FIG. 8 . Further, it is often necessary to meet other specific water treatment parameters before the water can be reused in such once-through steam generators 12 for the generation of high pressure steam.
[0007] In most prior art water treatment schemes, the de-oiled recovered water 46 must be treated in a costly water treatment plant sub-system 101 before it can be sent to the steam generators 12 . Treatment of water before feed to the once-through steam generators 12 is often initially accomplished by using a warm lime softener 50 , which removes hardness, and which also removes some silica from the de-oiled produced water feedstream 46 . Various softening chemicals 52 are usually necessary, such as lime, flocculating polymer, and perhaps soda ash. The softener clarifier 54 underflow 56 produces a waste sludge 58 which must be further handled and disposed. Then, an “after-filter” 60 is often utilized on the clarate stream 59 from the softener clarifier 54 , to prevent carry-over from the softener clarifier 54 of any precipitate or other suspended solids, which substances are thus accumulated in a filtrate waste stream 62 . For polishing, an ion exchange step 64 , normally including a hardness removal step such as a weak acid cation (WAC) ion-exchange system that can be utilized to simultaneously remove hardness and the alkalinity associated with the hardness, is utilized. The ion exchange systems 64 require regeneration chemicals 66 as is well understood by those of ordinary skill in the art and to which this disclosure is directed. As an example, however, a WAC ion exchange system is usually regenerated with hydrochloric acid and caustic, resulting in the creation of a regeneration waste stream 68 . Overall, such prior art water treatment plants are relatively simple, but, result in a multitude of liquid waste streams or solid waste sludges that must be further handled, with significant additional expense.
[0008] In one relatively new heavy oil recovery process, known as the steam assisted gravity drainage heavy oil recovery process (the “SAGD” process), it is preferred that one hundred percent (100%) quality steam be provided for injection into wells (i.e., no liquid water is to be provided with the steam to be injected into the formation). Such a typical prior art system 11 is depicted in FIG. 2 . However, given conventional prior art water treatment techniques as just discussed in connection with FIG. 1 , the 100% steam quality requirement presents a problem for the use of once through steam generators 12 in such a process. That is because in order to produce 100% quality steam 70 using a once-through type steam generator 12 , a vapor-liquid separator 72 is required to separate the liquid water from the steam. Then, the liquid blowdown 73 recovered from the separator is typically flashed several times in a series of flash tanks F 1 , F 2 , etc. through F N (where N is a positive integer equal to the number of flash tanks) to successively recover as series of lower pressure steam flows S 1 , S 2 , etc. which may sometimes be utilized for other plant heating purposes. After the last flashing stage F N , a residual hot water final blowdown stream 74 must then be handled, by recycle and/or disposal. The 100% quality steam is then sent down the injection well 16 and injected into the desired formation 20 . Fundamentally, though, conventional treatment processes for produced water used to generate steam in a once-through steam generator produces a boiler blowdown which is roughly twenty percent (20%) of the feedwater volume. This results in a waste brine stream that is about fivefold the concentration of the steam generator feedwater. Such waste brine stream must be disposed of by deep well injection, or if there is limited or no deep well capacity, by further concentrating the waste brine in a crystallizer or similar system which produces a dry solid for disposal.
[0009] As depicted in FIG. 3 , another method which has been proposed for generating the required 100% quality steam for use in the steam assisted gravity drainage process involves the use of boilers 80 , which may be packaged, factory built boilers of various types or field assembled boilers with mud and steam drums and water wall piping. Various methods can be used for producing water of a sufficient quality to be utilized as feedwater 80 F to a boiler 80 . One method which has been developed for use in heavy oil recovery operations involves de-oiling 40 of the produced water 36 , followed by a series of physical-chemical treatment steps. Such treatment steps normally include a series of unit operations as warm lime softening 54 , followed by filtration 60 for removal of residual particulates, then an organic trap 84 (normally non-ionic ion exchange resin) for removal of residual organics. The organic trap 84 may require a regenerant chemical supply 85 , and, in any case, produces a waste 86 , such as a regenerant waste. Then, a pre-coat filter 88 can be used, which has a precoat filtrate waste 89 . In one alternate embodiment, an ultrafiltration (“UF”) unit 90 can be utilized, which unit produces a reject waste stream 91 . Then, effluent from the UF unit 90 or precoat filter 88 can be sent to a reverse osmosis (“RO”) system 92 , which in addition to the desired permeate 94 , produces a reject liquid stream 96 that must be appropriately handled. Permeate 94 from the RO system 92 , can be sent to an ion exchange unit 100 , typically but not necessarily a mixed bed demineralization unit, which of course requires regeneration chemicals 102 and which consequently produces a regeneration waste 104 . And finally, the boiler 80 produces a blowdown 110 which must be accommodated for reuse or disposal.
[0010] The prior art process designs, such as depicted in FIG. 3 , for utilizing packaged boilers in heavy oil recovery operations, have a high initial capital cost. Also, such a series of unit process steps involves significant ongoing chemical costs. Moreover, there are many waste streams to discharge, involving a high and ongoing sludge disposal cost. Further, where membrane systems such as ultrafiltration 90 or reverse osmosis 92 are utilized, relatively frequent replacement of membranes 106 or 108 , respectively, may be expected, with accompanying on-going periodic replacement costs. Also, such a process scheme can be labor intensive to operate and to maintain.
[0011] In summary, the currently known and utilized methods for treating heavy oil field produced waters in order to generate high quality steam for down-hole use are not entirely satisfactory because:
such physical-chemical treatment process schemes are usually quite extensive, are relatively difficult to maintain, and require significant operator attention; such physical-chemical treatment processes require many chemical additives which must be obtained at considerable expense, and many of which require special attention for safe handling; such physical-chemical treatment processes produce substantial quantities of undesirable sludges and other waste streams, the disposal of which is increasingly difficult, due to stringent environmental and regulatory requirements.
[0015] It is clear that the development of a simpler, more cost effective approach to produced water treatment would be desirable in the process of producing steam in heavy oil production operations. Thus, it can be appreciated that it would be advantageous to provide a new produced water treatment process which minimizes the production of undesirable waste streams, while minimizing the overall costs of owning and operating a heavy oil recovery plant.
SOME OBJECTS, ADVANTAGES, AND NOVEL FEATURES
[0016] The new water treatment process(es) disclosed herein, and various embodiments thereof, can be applied to heavy oil production operations. Such embodiments are particularly advantageous in that they minimize the generation of waste products, and are otherwise superior to water treatment processes heretofore used or proposed in the recovery of bitumen from tar sands or other heavy oil recovery operations.
[0017] From the foregoing, it will be apparent to the reader that one of the important and primary objectives resides in the provision of a novel process, including several variations thereof, for the treatment of produced waters, so that such waters can be re-used in producing steam for use in heavy oil recovery operations.
[0018] Another important objective is to simplify process plant flow sheets, i.e., minimize the number of unit processes required in a water treatment train, which importantly simplifies operations and improves quality control in the manufacture of high purity water for down-hole applications.
[0019] Other important but more specific objectives reside in the provision of various embodiments for an improved water treatment process for production of high purity water for down-hole use in heavy oil recovery, which embodiments may:
in one embodiment, eliminate the requirement for flash separation of the high pressure steam to be utilized downhole from residual hot pressurized liquids; eliminate the generation of softener sludges; minimize the production of undesirable liquid or solid waste streams; minimize operation and maintenance labor requirements; minimize maintenance materiel requirements; minimize chemical additives and associated handling requirements; increase reliability of the OTSG's, when used in the process; decouple the de-oiling operations from steam production operations; and reduce the initial capital cost of water treatment equipment.
[0029] Other important objectives, features, and additional advantages of the various embodiments of the novel process disclosed herein will become apparent to the reader from the foregoing and from the appended claims and the ensuing detailed description, as the discussion below proceeds in conjunction with examination of the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
[0030] In order to enable the reader to attain a more complete appreciation of the novel water treatment process disclosed and claimed herein, and the various embodiments thereof, and of the novel features and the advantages thereof over prior art processes, attention is directed to the following detailed description when considered in connection with the accompanying figures of the drawing, wherein:
[0031] FIG. 1 shows one typical prior art process, namely a generalized process flow diagram for a physical-chemical water treatment process configured for use in heavy oil recovery operations.
[0032] FIG. 2 shows another prior art process, namely a generalized process flow diagram for a physical-chemical water treatment process as used in a steam assisted gravity drainage (SAGD) type heavy oil operation.
[0033] FIG. 3 shows yet another prior art physical-chemical treatment process scheme, also as it might be applied for use in steam assisted gravity drainage (SAGD) type heavy oil recovery operations.
[0034] FIG. 4 shows one embodiment of an evaporation based water treatment process, illustrating the use of a seeded slurry evaporation based process in combination with the use of packaged boilers for steam production, as applied to heavy oil recovery operations.
[0035] FIG. 5 shows another embodiment for an evaporation based water treatment process for heavy oil production, illustrating the use of a seeded slurry evaporation process in combination with the use of once-through steam generators for steam production, as applied to heavy oil recovery operations, which process is characterized by feed of evaporator distillate to once-through steam generators without the necessity of further pretreatment.
[0036] FIG. 6 shows a common variation for the orientation of injection and gathering wells as utilized in heavy oil recovery, specifically showing the use of horizontal steam injection wells and of horizontal oil/water gathering wells, as often employed in a steam assisted gravity drainage heavy oil gathering project.
[0037] FIG. 7 shows the typical feedwater quality requirements for steam generators which produce steam in the 1000 pounds per square inch gauge range, or thereabouts, for conventional steam boiler installations.
[0038] FIG. 8 shows the typical feedwater quality requirements for steam generators which produce steam in the 1000 pounds per square inch gauge range, or thereabouts, for once-through type steam generator installations.
[0039] FIG. 9 provides a simplified view of a vertical tube falling film evaporator operating in a seeded slurry mode in the treatment of produced water from heavy oil operations, for production of distillate for reuse in once through steam generators or in conventional steam boilers.
[0040] FIG. 10 shows further details of the use of evaporators operating in a seeded slurry mode, illustrated by use of falling film evaporators, and indicates selected injection points for acidification of the feedwater and for control of pH in the evaporator via optional injection of a selected base such as sodium hydroxide.
[0041] FIG. 11 illustrates the solubility of silica in water as a function of pH at 25° C. when such silica species are in equilibrium with amorphous silica, as well as the nature of such soluble silica species (molecule or ion) at various concentration and pH ranges.
[0042] FIG. 12 diagrammatically illustrates functional internal details of the operation of a falling film evaporator operating in a seeded slurry mode, which evaporator type would be useful in the evaporation of produced waters from heavy oil production; details illustrated include the production of steam from a falling brine film, by a heat exchange relationship from condensation of steam on a heat exchange tube, and the downward flow of such steam condensate (distillate) by gravity for the collection of such condensate (distillate) above the bottom tube sheet of the evaporator.
[0043] The foregoing figures, being merely exemplary, contain various elements that may be present or omitted from actual process implementations depending upon the circumstances. An attempt has been made to draw the figures in a way that illustrates at least those elements that are significant for an understanding of the various embodiments and aspects of the invention. However, various other elements of the unique process methods, and the combination of apparatus for carrying out the methods, are also shown and briefly described to enable the reader to understand how various features, including optional or alternate features, may be utilized in order to provide an efficient, low cost process design which can be implemented in a desired throughput size and physical configuration for providing optimum water treatment plant design and operation.
DESCRIPTION
[0044] Many steam assisted heavy oil recovery schemes, such as a steam assisted gravity drainage (SAGD) heavy oil recovery process injection and recovery well arrangements of the type depicted in FIG. 6 , most efficiently utilize a 100% quality steam supply 70 . It would therefore be desirable to produce such a steam supply by an efficient process scheme such as I have found may be provided by evaporation based heavy oil produced water treatment method(s). Various embodiments and details of such evaporation based produced water treatment method(s) are depicted in FIGS. 4, 5 , 6 , 9 , 10 and 12 .
[0045] As depicted in FIG. 6 , in a SAGD process, horizontal injection wells 16 ′ and horizontal oil/water gathering wells 30 ′ are advantageously utilized spaced apart within an oil bearing formation 20 . As particularly illustrated in FIGS. 4 and 5 , a process for the use of an evaporation based water treatment system 120 has been developed to treat produced water, in order to produce high quality steam for use in further heavy oil recovery. Conceptually, such an evaporative water treatment process may, in one embodiment, be situated process wise—that is, water flow wise—between the point of receipt of a de-oiled produced water stream 46 and the point of steam injection at well head 48 of injection well 16 . The process, in combination with the steam injection well 16 , oil recovery well 30 , and related oil water separation equipment 32 and de-oiling equipment 40 , and boilers 80 as shown in FIG. 4 , or alternately, once through steam generators 12 as shown in FIG. 5 , can substantially reduce capital costs and can minimize ongoing operation and maintenance costs of heavy oil recovery installations. Boilers 80 may be packaged, factory built boilers of various types or field assembled boilers with mud and steam drums and water wall piping, or more generally, conventional steam boilers. In some locales, such as northern Canada, the possibility of elimination of the need for handling of waste sludges and other waste streams made possible by the evaporation based water treatment system 120 may be especially important, since it may be difficult to work with such waste materials during the extremely cold winter months.
[0046] It has been observed that it may be desirable in some instances to use a packaged boiler 80 to produce the required steam 70 , rather than to utilize a traditional once-through type steam generator 12 to produce 80% quality steam 14 and then utilize separator(s) 130 to separate steam 132 from liquid 134 . It is noteworthy in such an economic process evaluation that packaged boilers 80 are often less expensive on a capital cost basis and on an operating cost basis than once-through type oil-field steam generators 12 . Also, package boilers can be utilized to produce pure steam 70 , and thus produce only a minimal liquid blowdown stream 110 . Also, as shown in FIGS. 4 and 5 , boiler blowdown stream can be either sent to the evaporator feed tank 210 , or injected into the sump reservoir 152 of evaporator 140 , such as via line 111 , or into a recirculating brine via line 111 ′. One type of packaged boiler suitable for use in the process described herein is a water tube boiler having a lower mud drum and an upper steam drum and water cooled sidewalls substantially extending therebetween in a manner which encloses a combustion chamber. However, most such packaged boilers require a much higher quality feed water 80 F than is the case with requirements for feedwater 12 F for a once-through type steam generator. As a result, in one embodiment, the process disclosed herein includes an evaporation unit 140 based approach to packaged boiler 80 feedwater 80 F pretreatment. In other words, the de-oiled produced water 46 generated can be advantageously treated by an evaporative process operating in a seeded slurry mode, particularly if the oil in the de-oiled produced water is reduced reliably to a selected low level of less than about 20 parts per million, or more preferably to less than about 10 parts per million, and provides a significantly improved method for produced water treatment in heavy oil production.
[0047] An oil/water mixture 22 is pumped up through oil gathering wells 30 . The oil water mixture 22 is sent to a series of oil/water separators 32 . An oil product 34 is gathered for further conditioning, transport, and sale. The produced water 36 which has been separated from the oil/water mixture 22 is then sent to a produced water de-oiling step 40 , which may be accomplished in dissolved air flotation units with the assistance of the addition of a de-oiling polymer 42 , or by other appropriate unit processes, to achieve a preselected low residual oil level such as less than 20 parts per million.
[0048] In the water treatment method disclosed herein, the de-oiled produced water 46 is treated and conditioned for feed to one or more mechanical vapor recompression evaporator units 140 (normally, multiple redundant units) to concentrate the incoming produced water stream 46 . The necessary treatment and conditioning prior to the evaporator unit 140 can be efficiently accomplished, but may vary somewhat based on feedwater chemistry—i.e. the identity and distribution of various dissolved and suspended solids—and on the degree of concentration selected for accomplishment in evaporator units 140 .
[0049] In one embodiment, it may be necessary or appropriate to add acid by line 144 , or at an appropriate point upstream of the feed tank 210 when desired such as via line 146 ′. A suitable acid may be sulfuric acid or hydrochloric acid, which is effective to lower the pH sufficiently so that bound carbonates are converted to free gaseous carbon dioxide, which is removed, along with other non-condensable gases 148 dissolved in the feedwater 46 such as oxygen and nitrogen, in an evaporator feedwater deaerator 150 . However, use of acid 144 is this manner is optional, and can sometimes be avoided if feedwater chemistry and the concentration limits of scale forming species are sufficiently low at the anticipated concentration factor utilized in evaporator 140 . For pH control, as seen in FIG. 10 , it may be useful to add a selected base such as caustic 232 to the concentrated brine recirculating in the evaporator 140 , which can be accomplished by direct injection of a selected base such as caustic 232 into the sump 141 , as indicated by line 157 , or by feed of a selected base such as caustic 232 into the suction of recirculation pump 153 , as indicated by line 159 . However, if the produced water contains an appreciable amount of calcium and sulfate, the mechanical vapor recompression evaporator 140 may in one embodiment be operated using a calcium sulfate seeded-slurry technique, normally in a near neutral pH range. That mode of operation can be made possible by the substantial elimination of carbonate alkalinity before the feedwater is introduced into the evaporator 140 . Then, the evaporator 140 may be operated a seeded-slurry mode wherein calcium sulfate and silica co precipitated recirculating seed crystals, which avoids scaling of the heat transfer surfaces.
[0050] At feedwater heat exchanger, the feedwater pump 149 is used to provide sufficient pressure to send feedwater from the evaporator feed tank 210 through the feedwater heat exchanger 148 , prior to the deaerator 150 . In the opposite direction, the distillate pump 143 moves distillate 180 through the feedwater heat exchanger 148 , so that the hot distillate is used to heat the feedwater stream directed toward the deaerator 150 .
[0051] The conditioned feedwater 151 is sent as feedwater to evaporator 140 . The conditioned feedwater 151 may be directed to the inlet of recirculation pump 153 , or alternately, directed to the sump 141 of evaporator 140 as indicated by broken line 151 ′ in FIG. 10 . Concentrated brine 152 in the evaporator 140 is recirculated via pump 153 , so only a small portion of the recirculating concentrated brine is removed on any one pass through the evaporator 140 . In the evaporator 140 , the solutes in the feedwater 46 are concentrated via removal of water from the feedwater 46 . As depicted in FIGS. 10 and 12 , an evaporator 140 is in one embodiment provided in a falling film configuration wherein a thin brine film 154 is provided by distributors 155 and then falls inside of a heat transfer element, e.g. tube 156 . A small portion of the water in the thin brine film 154 is extracted in the form of steam 160 , via heat given up from heated, compressed steam 162 which is condensing on the outside of heat transfer tubes 156 . Thus, the water is removed in the form of steam 160 , and that steam is compressed through the compressor 164 , and the compressed steam 162 is condensed at a heat exchange tube 156 in order to produce yet more steam 160 to continue the evaporation process. The condensing steam on the outer wall 168 of heat transfer tubes 156 , which those of ordinary skill in the evaporation arts and to which this disclosure is directed may variously refer to as either condensate or distillate 180 , is in relatively pure form, low in total dissolved solids. In one embodiment, such distillate contains less than 10 parts per million of total dissolved solids of non-volatile components. Since, as depicted in the embodiments shown in FIGS. 4, 5 , 9 , and 10 , a single stage of evaporation is provided, such distillate 180 may be considered to have been boiled, or distilled, once, and thus condensed but once.
[0052] Prior to the initial startup of the evaporator 140 in the seeded-slurry mode, the evaporator, which in such mode may be provided in a falling-film, mechanical vapor recompression configuration, the fluid contents of the unit are “seeded” by the addition of calcium sulfate (gypsum). The circulating solids within the brine slurry serve as nucleation sites for subsequent precipitation of calcium sulfate 272 , as well as silica 274 . Such substances both are precipitated as an entering feedwater is concentrated. Importantly, the continued concentrating process produces additional quantities of the precipitated species, and thus creates a continuing source of new “seed” material as these particles are broken up by the mechanical agitation, particularly by the action of the recirculation pump 153 .
[0053] In order to avoid silica and calcium sulfate scale buildup in the evaporator 140 , calcium sulfate seed crystals 272 are continuously circulated over the wetted surfaces, i.e., the falling film evaporator tubes 156 , as well as other wetted surfaces in the evaporator 140 . Through control of slurry concentration, seed characteristics, and system geometry, the evaporator can operate in the otherwise scale forming environment. The thermo chemical operation within the evaporator 140 with regard to the scale prevention mechanism is depicted in FIG. 12 . As the water is evaporated from the brine film 154 inside the tubes 156 , the remaining brine film becomes super saturated and calcium sulfate and silica start to precipitate. The precipitating material promotes crystal growth in the slurry rather than new nucleation that would deposit on the heat transfer surfaces; the silica crystals attach themselves to the calcium sulfate crystals. This scale prevention mechanism, called preferential precipitation, has a proven capability to promote clean heat transfer surfaces 260 . The details of one advantageous method for maintaining adequate seed crystals in preferentially precipitation systems is set forth in U.S. Pat. No. 4,618,429, issued Oct. 21, 1986 to Howard R. Herrigel, the disclosure of which is incorporated into this application in full by this reference.
[0054] It is to be understood that the falling film evaporator 140 design is provided only for purposes of illustration and thus enabling the reader to understand the water treatment process(es) taught herein, and is not intended to limit the process to the use of such evaporator design, as those in the art will recognize that other designs, such as, for example, a forced circulation evaporator, or a rising film evaporator, may be alternately utilized with the accompanying benefits and/or drawbacks as inherent in such alternative evaporator designs.
[0055] In any event, in a falling film evaporator embodiment, the distillate 180 descends by gravity along tubes 156 and accumulates above bottom tube sheet 172 , from where it is collected via condensate line 174 . A small portion of steam in equilibrium with distillate 180 may be sent via line 172 to the earlier discussed deaerator 150 for use in mass transfer, i.e, heating and steam stripping descending liquids in a packed tower to remove non-condensable gases 148 such as carbon dioxide. However, the bulk of the distillate 180 is removed as a liquid via line 180 ′, and may optionally be sent for further treatment in a distillate treatment plant, for example such as depicted in detail in FIG. 4 , or as merely depicted in functional form as feed 181 F for plant 181 in FIG. 5 , to ultimately produce a product water 181 P which is suitable for evaporator feedwater, such as feedwater 80 F′ in the case where packaged boilers 80 are utilized as depicted in FIG. 4 . The plant 181 also normally produces a reject stream 181 R which may be recycled to the evaporator feed tank 210 or other suitable location for reprocessing or reuse. As shown in the embodiment set forth in FIG. 5 , the distillate treatment plant 181 is optional, especially in the case of the use of once through steam generators, and in such instance the distillate 180 may often be sent directly to once-through steam generators as feedwater 12 F′ (as distinguished from the higher quality from feedwater 12 F discussed hereinabove with respect to prior art processes) for generation of 80% quality steam 14 . Also, as shown in FIG. 4 , a distillate treatment plant 181 may also be optional in some cases, depending on feedwater chemistry, and in such cases, distillate 180 may be fed directly to boiler 80 as indicated by broken line 81 .
[0056] In an embodiment where boilers 80 are used rather than once through steam generators 12 , however, it may be necessary or desirable to remove the residual organics and other residual dissolved solids from the distillate 180 before feed of distillate 180 to the boilers 80 . For example, as illustrated in FIG. 4 , in some cases, it may be necessary to remove residual ions from the relatively pure distillate 180 produced by the evaporator 140 . In most cases the residual dissolved solids in the distillate involve salts other than hardness. In one embodiment, removal of residual dissolved solids can be accomplished by passing the evaporator distillate 180 , after heat exchanger 200 , through an ion exchange system 202 . Such ion-exchange systems may be of mixed bed type or include an organic trap, and directed to remove the salts and/or organics of concern in a particular water being treated. In any event, regenerant chemicals 204 will ultimately be required, which regeneration results in a regeneration waste 206 that must be further treated. Fortunately, in the process scheme described herein, the regeneration waste 206 can be sent back to the evaporator feed tank 210 for a further cycle of treatment through the evaporator 140 .
[0057] In another embodiment, removal of residual dissolved solids can be accomplished by passing the evaporator distillate 180 through a heat exchanger 200 ′ and then through electrodeionization (EDI) system 220 . The EDI reject 222 is also capable of being recycled to evaporator feed tank 210 for a further cycle of treatment through the evaporator 140 .
[0058] The just described novel combination of process treatment steps produces feedwater of sufficient quality, and in economic quantity, for use in packaged boilers 80 in heavy oil recovery operations. Advantageously, when provided as depicted in FIG. 4 a single liquid waste stream is generated, namely evaporator blowdown 230 , which contains the concentrated solutes originally present in feedwater 46 , along with additional contaminants from chemical additives (such as regeneration chemicals 204 ). Also, in many cases, even the evaporator blowdown 230 can be disposed in an environmentally acceptable manner, which, depending upon locale, might involve injection in deep wells 240 . Alternately, evaporation to complete dryness in a zero discharge system 242 , such as a crystallizer or drum dryer, to produce dry solids 244 for disposal, may be advantageous in certain locales.
[0059] Various embodiments for new process method(s), as set forth in FIGS. 4 and 5 for example, are useful in heavy oil production since they generally offer one or more of the following advantages: (1) eliminate many physical-chemical treatment steps commonly utilized previously in handing produced water (for example, lime softening, filtrating, ion exchange systems, and certain de-oiling steps are eliminated); (2) result in lower capital equipment costs, since the evaporative approach to produced water treatment results in a zero liquid discharge system footprint size that is about 80% smaller than that required if a prior art physical-chemical treatment scheme is utilized, as well as eliminating vapor/liquid separators and reducing the size of the boiler feed system by roughly 20%; (3)-result in lower operating costs for steam generation; (4) eliminate the production of softener sludge, thus eliminating the need for the disposal of the same; (5) eliminate other waste streams, thus minimizing the number of waste streams requiring disposal; (6) minimize the materiel and labor required for maintenance; (7) reduce the size of water de-oiling equipment in most operations; and (8) decouple the de-oiling operations from the steam generation operations.
[0060] One of the significant economic advantages of using a vertical tube, falling film evaporator such as of the type described herein is that the on-line reliability and redundancy available when multiple evaporators are utilized in the treatment of produced water. An evaporative based produced water treatment system can result in an increase of from about 2% to about 3% or more in overall heavy oil recovery plant availability, as compared to a produced water treatment system utilizing a conventional prior art lime and clarifier treatment process approach. Such an increase in on-line availability relates directly to increased oil production and thus provides a large economic advantage over the life of the heavy oil recovery plant.
[0061] In the process disclosed herein, the evaporator 140 is designed to produce high quality distillate (typically 2-5 ppm non-volatile TDS) which, after temperature adjustment to acceptable levels in heat exchangers 200 or 200 ′ (typically by cooling to about 45° C., or lower) can be fed directly into polishing equipment (EDI system 220 , ion exchange system 202 , or reverse osmosis system 224 ) for final removal of dissolved solids. The reject stream 221 from the reverse osmosis system can be recycled to the evaporator feed tank 210 for further treatment. Likewise, the reject from the EDI system may be recycled to the evaporator feed tank 210 for further treatment. Similarly, the regenerant from most ion exchange processes 202 may be recycled to the evaporator feed tank 210 for further treatment. The water product produced by the polish equipment just mentioned is most advantageously used as feedwater for the packaged boiler 80 . That is because in the typical once-though steam generator 12 used in oil field operations, it is normally unnecessary to incur the additional expense of final polishing by removal of residual total dissolved solids from the evaporator distillate stream 180 . In some applications, final polishing is not necessary when using conventional boilers 80 . This can be further understood by reference to FIG. 6 , where a typical boiler feed water chemistry specification is presented for (a) packaged boilers, and (b) once-through steam generators. It may be appropriate in some embodiments from a heat balance standpoint that the de-oiled produced waters 46 fed to the evaporator for treatment be heated by heat exchange with the distillate stream 180 . However, if the distillate stream is sent directly to once-through steam generators 12 , then no cooling of the distillate stream 180 may be appropriate. Also, in the case of once-through steam generators 12 , it may be necessary or appropriate to utilize a plurality of flash tanks F 1 , etc., in the manner described above with reference to FIG. 2 .
[0062] Also, as briefly noted above, but significantly bears repeating, in those cases where the EDI system 220 is utilized for polishing, the membrane reject stream includes an EDI reject stream 222 that is recycled to be mixed with the de-oiled produced water 46 in the evaporator feed tank 210 system, for reprocessing through the evaporator 140 . Similarly, when reverse osmosis is utilized the a membrane reject stream includes the RO reject stream which is recycled to be mixed with the de-oiled produced water 46 in the evaporator feed tank 210 system, for reprocessing through the evaporator 140 . Likewise, when ion-exchange system 202 is utilized, the regenerant waste stream 206 is recycled to be mixed with the de-oiled produced water 46 in the evaporator feed tank system, for reprocessing through the evaporator 140 .
[0063] Again, it should be emphasized that the blowdown 230 from the evaporator 140 is often suitable for disposal by deep well 240 injection. Alternately, the blowdown stream can be further concentrated and/or crystallized using a crystallizing evaporator, or a crystallizer, in order to provide a zero liquid discharge 242 type operation. This is an important advantage, since zero liquid discharge operations may be required if the geological formation is too tight to allow water disposal by deep well injection, or if regulatory requirements do not permit deep well injection.
[0064] Many produced waters encountered in heavy oil production are high in silica, with values that may range up to about 200 mg/l as SiO 2 , or higher. Use of a seeded slurry operational configuration in evaporator 140 co-precipitates silica with precipitating calcium sulfate, to provide a process design which prevents the scaling of the inner surfaces 260 of the heat transfer tubes 156 with the ever-present silica. This is important, since silica solubility must be accounted for in the design and operation of the evaporator 140 , in order to prevent silica scaling of the heat transfer surfaces 260 .
[0065] Since the calcium hardness and sulfate concentrations of many produced waters is low (typically 20-50 ppm Ca as CaCO3), it is possible in many cases to operate the evaporators 140 with economically efficient concentration factors, while remaining below the solubility limit of calcium sulfate, assuming proper attention to feedwater quality and to pre-treatment processes.
[0066] It is to be appreciated that the water treatment process described herein for preparing boiler feedwater in heavy oil recovery operations is an appreciable improvement in the state of the art of water treatment for oil recovery operations. The process eliminates numerous of the heretofore encountered waste streams, while processing water in reliable mechanical evaporators, and in one embodiment, in mechanical vapor recompression (“MVR”) evaporators. Polishing, if necessary, can be accomplished in ion exchange, electrodeionization, or reverse osmosis equipment. The process thus improves on currently used treatment methods by eliminating most treatment or regeneration chemicals, eliminating many waste streams, eliminating some types of equipment. Thus, the complexity associated with a high number of treatment steps involving different unit operations is avoided.
[0067] In the improved water treatment method, the control over waste streams is focused on a the evaporator blowdown, which can be conveniently treated by deep well 240 injection, or in a zero discharge system 242 such as a crystallizer and/or spray dryer, to reduce all remaining liquids to dryness and producing a dry solid 244 . This contrasts sharply with the prior art processes, in which sludge from a lime softener is generated, and in which waste solids are gathered at a filter unit, and in which liquid wastes are generated at an ion exchange system and in the steam generators. Moreover, this waste water treatment process also reduces the chemical handling requirements associated with water treatment operations.
[0068] It should also be noted that the process described herein can be utilized with once through steam generators, since due to the relatively high quality feedwater—treated produced water—provided to such once through steam generators, the overall blowdown rate of as low as about 5% or less may be achievable in the once through steam generator. Alternately, as shown in FIG. 5 , at least a portion of the liquid blowdown 134 from the once through steam generator 12 can be recycled to the steam generator 12 , such as indicated by broken line 135 to feed stream 12 F′.
[0069] In yet another embodiment, to further save capital and operating expense, industrial boilers of conventional design may be utilized since the distillate—treated produced water—may be of sufficiently good quality to be an acceptable feedwater to the boiler, even if it requires some polishing. It is important to observe that use of such boilers reduces the boiler feed system and evaporative produced water treatment system size by twenty percent (20%), eliminates vapor/liquid separation equipment as noted above, and reduces the boiler blowdown flow rate by about ninety percent (90%).
[0070] In short, evaporative treatment of produced waters using a falling film, vertical tube evaporator is technically and economically superior to prior art water treatment processes for heavy oil production. It is possible to recover ninety five percent (95%) or more, and even up to ninety eight percent (98%) or more, of the produced water as high quality distillate 180 for use as high quality boiler feedwater (resulting in only a 2% boiler blowdown stream which can be recycled to the feed for evaporator 140 ). Such a high quality distillate stream may be utilized in SAGD and non-SAGD heavy oil recovery operations. Such a high quality distillate stream may have less than 10 mg/L of non-volatile inorganic TDS and is useful for feed either to OTSGs or to conventional boilers.
[0071] The overall life cycle costs for the novel treatment process described herein are significantly less than for a traditional lime softening and ion exchange treatment system approach. And, an increase of about 2% to 3% in overall heavy oil recovery plant availability is achieved utilizing the treatment process described herein, which directly results in increased oil production from the facility. Since boiler blowdown is significantly reduced, by as much as 90% or more, the boiler feed system may be reduced in size by as much as fifteen percent (15%) or more. Finally, the reduced blowdown size results in a reduced crystallizer size when zero liquid discharge is achieved by treating blowdown streams to dryness.
[0072] Although only several exemplary embodiments of this invention have been described in detail, it will be readily apparent to those skilled in the art that the novel produced waste treatment process, and the apparatus for implementing the process, may be modified from the exact embodiments provided herein, without materially departing from the novel teachings and advantages provided by this invention, and may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Therefore, the disclosures presented herein are to be considered in all respects as illustrative and not restrictive. It will thus be seen that the objects set forth above, including those made apparent from the preceding description, are efficiently attained. Many other embodiments are also feasible to attain advantageous results utilizing the principles disclosed herein. Therefore, it will be understood that the foregoing description of representative embodiments of the invention have been presented only for purposes of illustration and for providing an understanding of the invention, and it is not intended to be exhaustive or restrictive, or to limit the invention only to the precise forms disclosed.
[0073] All of the features disclosed in this specification (including any accompanying claims, and the drawing) may be combined in any combination, except combinations where at least some of the features are mutually exclusive. Alternative features serving the same or similar purpose may replace each feature disclosed in this specification (including any accompanying claims, and the drawing), unless expressly stated otherwise. Thus, each feature disclosed is only one example of a generic series of equivalent or similar features. Further, while certain process steps are described for the purpose of enabling the reader to make and use certain water treatment processes shown, such suggestions shall not serve in any way to limit the claims to the exact variation disclosed, and it is to be understood that other variations, including various treatment additives or alkalinity removal techniques, may be utilized in the practice of my method.
[0074] The intention is to cover all modifications, equivalents, and alternatives falling within the scope and spirit of the invention, as expressed herein above and in any appended claims. The scope of the invention, as described herein and as indicated by any appended claims, is thus intended to include variations from the embodiments provided which are nevertheless described by the broad meaning and range properly afforded to the language of the claims, as explained by and in light of the terms included herein, or the legal equivalents thereof.
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A process for treating produced water to generate high pressure steam. Produced water from heavy oil recovery operations is treated by first removing oil and grease. Feedwater is then acidified and steam stripped to remove alkalinity and dissolved non-condensable gases. Pretreated produced water is then fed to an evaporator. Up to 95% or more of the pretreated produced water stream is evaporated to produce (1) a distillate having a trace amount of residual solutes therein, and (2) evaporator blowdown containing substantially all solutes from the produced water feed. The distillate may be directly used, or polished to remove the trace residual solutes before being fed to a steam generator. Steam generation in a packaged boiler, such as a water tube boiler having a steam drum and a mud drum with water cooled combustion chamber walls, produces 100% quality high pressure steam for down-hole use.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional patent application No. 61/561,146, filed Nov. 17, 2011, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to medical devices useful in in vivo environments, in particular, methods and materials used to sterilize such devices prior to their implantation in vivo.
[0004] 2. Description of Related Art
[0005] Medical personnel and patients commonly utilize a wide variety of pre-sterilized medical products, such as glucose sensors that are used by diabetic patients. In this context, a number of different sterilization processes are used with various medical products in order to kill microorganisms that may be present. Most sterilization processes require the sterilizing agent to systemically permeate the article being sterilized. These methods can include heat sterilization, where the object to be sterilized is subjected to heat and pressure, such as in an autoclave. The heat and pressure penetrates though the object being sterilized and after a sufficient time will kill the harmful microorganisms. Gases such as hydrogen peroxide or ethylene oxide are also used to sterilize objects. Sterilization methods also include those that use ionizing radiation, such as gamma-rays, x-rays, or energetic electrons to kill microorganisms.
[0006] Radiation has a number of advantages over other sterilization processes including a high penetrating ability, relatively low chemical reactivity, and instantaneous effects without the need to control temperature, pressure, vacuum, or humidity. Consequently, the sterilization of medical devices by exposure to radiation is a common practice. Medical devices composed in whole or in part of polymers are typically sterilized by various kinds of radiation, including, but not limited to, electron beam (e-beam), gamma ray, ultraviolet, infra-red, ion beam, and x-ray sterilization.
[0007] Electron-beam and gamma ray sterilization processes provide forms of radiation commonly used to kill microbial organisms on medical devices. However, when used to kill microorganisms, such radiation can alter the structure of functional macromolecules present in medical products including polymers such as proteins. High-energy radiation tends to produce ionization and excitation in polymer molecules, as well as free radicals. These energy-rich species can react with macromolecules present in medical products and undergo dissociation, abstraction, chain scission and cross-linking.
[0008] The deterioration of the performance of polymeric materials and other macromolecules in medical devices due to radiation sterilization has been associated with free radical formation during radiation exposure. Electron-beam and gamma ray radiation can therefore be problematical when used to sterilize medical device includes components that are radiation sensitive. This complicates the sterilization process and limits the range of designs or materials available for medical devices. Consequently, methods and formulations that can protect medical device materials from damage that can occur as a result of exposure to high-energy radiation are desirable.
SUMMARY OF THE INVENTION
[0009] As noted above, the sterilization of medical devices by exposure to radiation is a common practice. Unfortunately, radiation sterilization can compromise the function of certain components of some medical devices. In this context, embodiments of the invention provide methods and materials that can be used to protect medical devices from unwanted effects of radiation sterilization. While typical embodiments of the invention pertain to glucose sensors, the systems, methods and materials disclosed herein can be adapted for use with a wide variety of medical devices.
[0010] The invention disclosed herein has a number of embodiments. Typical embodiments of the invention comprise methods for inhibiting damage to a saccharide sensor that can result from a radiation sterilization process (e.g. electron beam irradiation) by combining the saccharide sensor with an aqueous radioprotectant formulation during the sterilization process. In common embodiments of the invention, the saccharide sensor comprises a saccharide binding polypeptide having a carbohydrate recognition domain and the aqueous radioprotectant formulation comprises a saccharide selected for its ability to bind the saccharide binding polypeptide. In certain embodiments of the invention, the saccharide sensor comprises a fluorophore; and the aqueous radioprotectant formulation comprises a fluorophore quenching composition selected for its ability to quench the fluorophore. In illustrative embodiments of the invention, the sensor is a glucose sensor and the saccharide binding polypeptide comprises mannan binding lectin, concanavalin A, glucose-galactose binding protein, or glucose oxidase. In certain methods of the invention, the sterilization process is performed under conditions selected so that the saccharide binds the saccharide binding polypeptide and/or the fluorophore quenching composition quenches the fluorophore in a manner that inhibits damage to the saccharide sensor that can result from the radiation sterilization process.
[0011] As discussed below, a number of compounds are useful in the radioprotectant formulations disclosed herein. In certain embodiments of the invention, the aqueous radioprotectant formulation comprises a saccharide such as glucose, mannose, fructose, melizitose, N-acetyl-D-glucosamine, sucrose or trehalose. In some embodiments, the aqueous radioprotectant formulation comprises an antioxidant selected from the group consisting of ascorbate, urate, nitrite, vitamin E, α-tocopherol or nicotinate methylester. In certain embodiment of the invention, the aqueous radioprotectant formulation comprises a buffering agent, for example, one selected from the group consisting of citrate, tris(hydroxymethyl)aminomethane (TRIS) and tartrate. In various embodiments of the invention the radioprotectant formulations can comprise additional agents such as surfactants, amino acids, pharmaceutically acceptable salts and the like. Related embodiments of the invention include compositions of matter comprising a medical device combined with an aqueous radioprotective formulation. One illustrative embodiment of the invention is a composition of matter comprising a saccharide sensor that includes a saccharide binding polypeptide; and/or a fluorophore. In typical composition embodiments, a saccharide sensor is combined with an aqueous radioprotectant formulation comprising a saccharide, wherein the saccharide binds to the saccharide binding polypeptide. Optionally in such compositions, the saccharide sensor is combined with a fluorophore quenching compound in the aqueous radioprotective formulation.
[0012] A number of compounds can be combined with the saccharide sensors disclosed herein to form the radioprotectant compositions of the invention. In typical embodiments of the invention, the composition comprises a saccharide selected from the group consisting of glucose, mannose, fructose, melizitose, N-acetyl-D-glucosamine, sucrose or trehalose. In certain embodiment of the invention, the composition comprises a fluorophore quenching compound, for example, acetaminophen. In some embodiments of the invention, the composition comprises an antioxidant compound is selected from the group consisting of ascorbate, urate, nitrite, vitamin E, α-tocopherol or nicotinate methylester. In some embodiments of the invention, the composition comprises a surfactant, for example a polysorbate such as Tween 80. In certain embodiments of the invention, the composition comprises a buffering agent such as citrate, tris(hydroxymethyl)aminomethane (TRIS) or tartrate.
[0013] Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description and specific examples, while indicating some embodiments of the present invention are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE FIGURES
[0014] FIG. 1A shows a sensor design comprising a tubular capsule that is implanted under the skin and provides optical sensor in response to analyte (glucose). FIG. 1B shows a view of this capsule. FIG. 1C shows the relative size of this capsule. FIG. 1D shows a diagram of shows an alternative sensor design, one comprising an amperometric analyte sensor formed from a plurality of planar layered elements.
[0015] FIG. 2 shows a bar graph of data presenting dose response (DR) retention as a function of ebeam radiation dose for non-formulated sensors (control sensors not combined with any radioprotectant compositions), triple dose and formulated sensors at 15 kGy. The triple dose is 3×5 kGy. The sensors tested were radiated wet in a solution comprising 50 mM Tris-buffer saline. The arrow symbolizes that we can retain +80% of DR after exposure to 15 kGy for formulated sensors.
[0016] FIG. 3 shows a plot of phase and intensity data obtained from sensors after exposure to 15 kGy of radiation. The dose response is 1.7 after radiation compared to 2.1 before i.e. a retention of 81%.
[0017] FIG. 4 shows a graph of data on DR retained for irradiated sensors as a function of Ascorbate concentration used for formulation. Too low or too high concentrations of Ascorbate used both yield low retained DR whereas the 20 mM to 100 mM concentration range yields good protection.
[0018] FIG. 5 shows a graph of data on DR retained for irradiated sensors as a function of Acetaminophen (=paracetamol, hence abbreviated PAM) concentration used for formulation. It is seen that using low concentrations of Acetaminophen yields low retained DR whereas the use of concentrations above 10 mM yields good protection. Further it is shown that adding Ascorbate to the excipients in most cases provides better protective effects.
[0019] FIG. 6 shows a graph of data on DR retained for irradiated sensors as a function of Acetaminophen concentration used for formulation.
[0020] FIG. 7 shows a graph of data of DR retained for irradiated sensors as a function of Acetaminophen concentration used for formulation. All sensors have contained 100 mM Sucrose and variation of additions of Ascorbate and Mannose are also shown.
[0021] FIG. 8 shows a graph of data of DR retained for irradiated sensors as a function of Ascorbate concentration used for formulation. All sensors have contained 500 mM Sucrose and variation of additions of Acetaminophen (PAM) and Mannose are also shown.
[0022] FIG. 9 shows a bar graph of data presenting the absolute DR for both radiated and non-radiated sensor as a function of formulating the sensors with Acetaminophen and Ascorbic acid/ascorbate.
[0023] FIG. 10 shows a bar graph of data presenting the absolute DR for both radiated and non-radiated sensor as a function of formulating the sensors with Acetaminophen, Ascorbic acid, Mannose and 500 mM Sucrose. The overall result is illustrated in FIG. 11 .
[0024] FIG. 11 shows a graph of data showing sensor response after using Tris/Citrate saline buffer+excipients. Sensors show good retention of DR.
[0025] FIG. 12 shows a graph of data presenting a direct comparison of e-beamed and non e-beamed sensors.
[0026] FIG. 13 shows a graph of data obtained from a native sensor tested after storage in PBS pH=5.5. The sensor itself has no problem with the PBS buffer.
[0027] FIG. 14 shows a graph of data obtained from a sensor with excipients added (500 mM sucrose, 20 mM Acetaminophen and 50 mM Ascorbate) in PBS buffer during e-beam irradiation.
[0028] FIG. 15 shows a graph of data obtained from a sensor with excipients added (500 mM sucrose, 20 mM Acetaminophen and 50 mM Ascorbate) in PBS buffer.
[0029] FIG. 16 shows a bar graph of data on retained DR for using different buffer concentrations.
[0030] FIG. 17 shows a graph of data resulting from sensors using citrate only during e-beam irradiation.
[0031] FIG. 18 shows a graph of data resulting from sensors using citrate and excipients during e-beam irradiation.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0032] Unless otherwise defined, all terms of art, notations and other scientific terms or terminology used herein are intended to have the meanings commonly understood by those of skill in the art to which this invention pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and/or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a substantial difference over what is generally understood in the art. Many of the techniques and procedures described or referenced herein are well understood and commonly employed using conventional methodology by those skilled in the art. As appropriate, procedures involving the use of commercially available kits and reagents are generally carried out in accordance with manufacturer defined protocols and/or parameters unless otherwise noted.
[0033] A number of terms are defined below.
[0034] The term “sensor” for example in “analyte sensor,” is used in its ordinary sense, including, without limitation, means used to detect a compound such as an analyte. A “sensor system” includes, for example, elements, structures and architectures (e.g. specific 3-dimensional constellations of elements) designed to facilitate sensor use and function. Sensor systems can include, for example, compositions such as those having selected material properties, as well as electronic components such as elements and devices used in signal detection (e.g. optical detectors, current detectors, monitors, processors and the like). The term “sensing complex” as used herein refers to the elements of a sensor that interact with and generate a signal indicative of, a particular analyte (e.g. glucose and the like). The term “matrix” is used herein according to its art-accepted meaning of something within or from which something else is found, develops, and/or takes form. While typical embodiments of the invention pertain to glucose sensors used in the management of diabetes, the systems, methods and materials disclosed herein can be adapted for use with a wide variety of medical devices known in the art.
[0035] In the management of diabetes, the regular measurement of glucose in the blood is essential in order to ensure correct insulin dosing. Furthermore, it has been demonstrated that in the long term care of the diabetic patient better control of the blood glucose levels can delay, if not prevent, the onset of retinopathy, circulatory problems and other degenerative diseases often associated with diabetes. Thus, there is a need for reliable and accurate self-monitoring of blood glucose levels by diabetic patients. Typically, blood glucose is monitored by diabetic patients with the use of commercially available colorimetric test strips or electrochemical biosensors (e.g. enzyme electrodes), both of which require the regular use of a lancet-type instrument to withdraw a suitable amount of blood each time a measurement is made. On average, the majority of diabetic patients would use such instruments to take a measurement of blood glucose twice a day. However, the U.S. National Institute of Health has recommended that blood glucose testing should be carried out at least four times a day, a recommendation that has been endorsed by the American Diabetes Association. This increase in the frequency of blood glucose testing imposes a considerable burden on the diabetic patient, both in financial terms and in terms of pain and discomfort, particularly in the long-term diabetic who has to make regular use of a lancet to draw blood from the fingertips. Thus, there is clearly a need for a better long-term glucose monitoring system that does not involve drawing blood from the patient.
[0036] There have been a number of proposals for glucose measurement techniques that do not require blood to be withdrawn from the patient. One method for assaying glucose via competitive binding uses a proximity-based signal generating/modulating moiety pair which is typically an energy transfer donor acceptor pair (comprising an energy donor moiety and an energy acceptor moiety). The energy donor moiety is photoluminescent (usually fluorescent). In such methods, an energy transfer donor-acceptor pair is brought into contact with the sample (such as subcutaneous fluid) to be analyzed. The sample is then illuminated and the resultant emission detected. Either the energy donor moiety or the energy acceptor moiety of the donor-acceptor pair is bound to a receptor carrier (for example a carbohydrate binding molecule), while the other part of the donor acceptor pair (bound to a ligand carrier, for example a carbohydrate analogue) and any analyte (for example carbohydrate) present compete for binding sites on the receptor carrier. Energy transfer occurs between the donors and the acceptors when they are brought together. An example of donor-acceptor energy transfer is fluorescence resonance energy transfer (Förster resonance energy transfer, FRET), which is non-radiative transfer of the excited-state energy from the initially excited donor (D) to an acceptor (A). Energy transfer produces a detectable lifetime change (reduction) of the fluorescence of the energy donor moiety. Also, a proportion of the fluorescent signal emitted by the energy donor moiety is quenched. The lifetime change is reduced or even eliminated by the competitive binding of the analyte. Thus, by measuring the apparent luminescence lifetime, for example, by phase-modulation fluorometry or time resolved fluorometry (see Lakowicz, Principles of Fluorescence Spectroscopy, Plenum Press, 1983, Chapter 3), the amount of analyte in the sample can be determined. The intensity decay time and phase angles of the donor are expected to increase with increasing analyte concentration. An important characteristic of FRET is that it occurs over distances comparable to the dimensions of biological macromolecules. The distance at which FRET is 50% efficient, called the Förster distance, is typically in the range of 20-60 Å. Förster distances ranging from 20 to 90 A are convenient for competitive binding studies. See, e.g. U.S. Pat. No. 6,232,120 and U.S. Patent Application Publication Nos. 20080188723, 20090221891, 20090187084 and 20090131773.
[0037] WO 91/09312 describes a subcutaneous method and device that employs an affinity assay based on glucose (incorporating an energy transfer donor acceptor pair) that is interrogated remotely by optical means. WO97/19188, WO 00/02048, WO 03/006992 and WO 02/30275 each describe glucose sensing by energy transfer, which produce an optical signal that can be read remotely. The systems discussed above rely on the plant lectin Concanavalin A (Con A) as the carbohydrate binding molecule. WO 06/061207 proposes that animal lectins such as mannose binding lectin (MBL) could be used instead. Previously disclosed carbohydrate analogues (e.g. those of U.S. Pat. No. 6,232,130) have comprised globular proteins to which carbohydrate and energy donor or energy acceptor moieties are conjugated. Carbohydrate polymers (e.g. optionally derivatized dextran and mannan) have also been used as carbohydrate analogues. In WO 06/061207 the use of periodate cleavage to allow binding of dextran to MBL at physiological calcium concentrations is disclosed. The assay components in such systems are typically retained by a retaining material. This may for example be a shell of biodegradable polymeric material, as described in WO 2005/110207.
[0038] Before implantable medical devices such as glucose sensors are introduced into the body, they must be sterilized. However, the materials of such devices, for example the assay components in sensors, can be sensitive to damage during sterilization. Heat sterilization causes denaturation of protein (lectin and/or carbohydrate analogue). Gas sterilization is difficult to use for wet devices such as the sensor. In view of this, the sterilization of medical devices by exposure to radiation is a common practice. Types of radiation which may be used in sterilization include gamma radiation and electron beam radiation. Electron beam radiation is easier to control than gamma radiation. However, electron beam radiation can lead to loss of protein activity and bleaching of dyes (e.g. a donor fluorophore and/or a acceptor dye). These effects can lead to loss of sensor activity.
[0039] Embodiments of the invention provide methods and materials that can be used to protect medical devices such as implantable glucose sensors from unwanted effects of radiation sterilization. The invention disclosed herein has a number of embodiments. Typical embodiments of the invention comprise methods for inhibiting damage to a medical device (e.g. a saccharide sensor) that can result from a radiation sterilization process by combining the medical device with an aqueous radioprotectant formulation during the sterilization process. In the context of embodiments of the invention as disclosed herein, because electron beam and gamma irradiation are fundamentally the same process, the protection provided by the methods and materials of the invention will be the same for these forms of irradiation. Gamma rays release secondary electrons from the materials around the item and hence create a cascade of electrons much like the e-beam. For this reason, gamma irradiation is suitable for sensors comprising one or more metal elements because metal is a good provider of secondary electrons. In some embodiments of the invention, the radiation sterilization process comprises electron beam irradiation. In some embodiments of the invention, the radiation sterilization process comprises gamma ray irradiation.
[0040] While the medical devices can be exposed to radiation supplied in multiple doses (e.g. 3×5 kGy for a total dose of 15 kGy), in typical embodiments of the instant invention, radiation is supplied in a single dose (e.g. 1×15 kGy for a total dose of 15 kGy). As disclosed herein (see, e.g. FIG. 2 ), supplying a sterilizing amount radiation in a single dose gives better radiation protection than supplying the same amount of radiation in multiple doses (dividing the radiation into a triple dose resulted in sensors having worse signal retention). Optionally, the total dose of radiation is not more than 35 kGy, and typically is in the range of. 10-20 kGy). In certain embodiments the total dose is 15 kGy±2 kGy. Gy (J/kg) is the SI unit of dose i.e. the amount of energy absorbed per unit mass. Following radiation exposure, sensor function parameters can be evaluated such as the sensor Dose Response (DR relative to 0 kGy DR) as well as the absolute DR (measured in degrees phase shift from 40 mg/dL glucose to 400 mg/dL glucose). In certain embodiments of the invention, an aqueous radiation protecting formulation functions to protect a glucose sensor from radiation damage so that the glucose sensor retains at least 50, 60 or 70% of its dose response (DR) to glucose following irradiation of the sensor (as compared to the DR of a control sensor that received no irradiation).
[0041] In some embodiments of the invention, the saccharide sensor comprises a boronic acid derivative such as those disclosed in U.S. Pat. Nos. 5,777,060, 6,002,954 and 6,766,183, the contents of which are incorporated herein by reference. In other embodiments of the invention, the saccharide sensor comprises a saccharide binding polypeptide. In certain embodiments of the invention the saccharide sensor comprises a lectin. Optionally the lectin is a C-type (calcium dependent) lectin. In some embodiments, the lectin is a vertebrate lectin, for example a mammalian lectin such as a human or humanized lectin. However, it may alternatively be a plant lectin, a bird lectin, a fish lectin or an invertebrate lectin such as an insect lectin. In certain embodiments, the lectin is in multimeric form. Multimeric lectins may be derived from the human or animal body. Alternatively, the lectin may be in monomeric form. Monomeric lectins may be formed by recombinant methods or by disrupting the binding between sub-units in a natural multimeric lectin derived from the human or animal body. Examples of this are described in U.S. Pat. No. 6,232,130. Saccharide sensors useful in embodiments of the invention are also disclosed in U.S. Patent Publication No. 2008/0188723, the contents of which are incorporated by reference.
[0042] In certain embodiments of the invention, the saccharide sensing element in a saccharide sensor comprises a lectin. Optionally, the lectin is mannose binding lectin, conglutinin or collectin-43 (e.g. bovine CL-43) (all serum collecting) or a pulmonary surfactant protein (lung collectins). Mannose binding lectin (also called mannan binding lectin or mannan binding protein, MBL, MBP), for example human MBL, has proved particularly interesting. MBL is a collagen-like defense molecule which comprises several (typically 3 to 4 (MALDI-MS), though distributions of 1 to 6 are likely to occur (SDS-PAGE)) sub-units in a “bouquet” arrangement, each composed of three identical polypeptides. Each sub-unit has a molecular weight of around 75 kDa, and can be optionally complexed with one or more MBL associated serine proteases (MASPs). Each polypeptide contains a CRD. Thus, each sub-unit presents three carbohydrate binding sites. Trimeric MBL and tetrameric MBL (which are the major forms present in human serum, Teillet et al., Journal of Immunology, 2005, page 2870-2877) present nine and twelve carbohydrate binding sites respectively. In typical embodiments of the invention, the lectin comprises polypeptides of Homo sapiens mannose-binding protein C precursor (NCBI Reference Sequence: NP — 000233.1). Serum MBL is made of 3-4 subunits of 3 polypeptides each. The sequence of NCBI Reference Sequence: NP — 000233.1 is between 27 kDa and 30 kDa giving the entire MBL protein a Mw typically of 270 kDa to 300 kDa.
[0043] Alternatively, the lectin may be a pulmonary surfactant protein selected from SP-A and SP-D. These proteins are similar to MBL. They are water-soluble collecting which act as calcium dependent carbohydrate binding proteins in innate host-defense functions. SP-D also binds lipids. SP-A has a “bouquet” structure similar to that of MBL (Kilpatrick D C (2000) Handbook of Animal Lectins, p. 37). SP-D has a tetrameric “X” structure with CRDs at each end of the “X”. Other suitable animal lectins are known in the art such as PC-lectin CTL-1, Keratinocyte membrane lectins, CD94, P35 (synonym: human L-ficolin, a group of lectins), ERGIC-53 (synonym: MR60), HIP/PAP, CLECSF8, DCL (group of lectins), and the GLUT family proteins, especially GLUT1, GLUT4 and GLUT11. Further suitable animal lectins are set out in Appendices A, B and C of “Handbook of Animal Lectins: Properties and Biomedical Applications”, David C. Kilpatrick, Wiley 2000.
[0044] In common embodiments of the invention, the saccharide sensor comprises a saccharide binding polypeptide having a carbohydrate recognition domain and the aqueous radioprotectant formulation comprises a saccharide selected for its ability to bind the saccharide binding polypeptide. In certain embodiments of the invention, the saccharide sensor comprises one or more fluorophores (e.g. a donor and/or a reference fluorophore); and the aqueous radioprotectant formulation comprises a fluorophore quenching compound selected for its ability to quench the fluorophore(s). Optionally, the sensor comprises at least one of protein/polypeptide, at least one energy donor, and/or at least one energy acceptor and this sensor is combined with at least one protective substance. In some embodiments the sensor comprises a protein, a fluorescent dye, dextran and a polymeric material. In illustrative embodiments of the invention, the sensor is a glucose sensor and the saccharide binding polypeptide comprises a mannan binding lectin, a concanavalin A, a glucose oxidase, or a glucose-galactose binding protein (see, e.g. U.S. Pat. No. 6,232,130; U.S. Patent Publication No. 2008/0188723; Jensen et al., Langmuir. 2012 Jul. 31; 28(30):11106-14. Epub 2012; Paek et al., Biosens Bioelectron. 2012 and Judge et al., Diabetes Technol Ther. 2011 March; 13(3):309-17, 2011, the contents of which are incorporated by reference).
[0045] As discussed below, a number of compounds are useful in the radioprotectant formulations disclosed herein. In certain embodiments of the invention, the aqueous radioprotectant formulation comprises a sugar such as glucose, mannose, fructose, melizitose, N-acetyl-D-glucosamine, sucrose or trehalose. In some embodiments, the aqueous radioprotectant formulation comprises an antioxidant selected from the group consisting of ascorbate, urate, nitrite, vitamin E, α-tocopherol or nicotinate methylester. In certain embodiment of the invention, the aqueous radioprotectant formulation comprises a buffering agent, for example, one selected from the group consisting of citrate, tris(hydroxymethyl)aminomethane (TRIS) and tartrate.
[0046] In typical methods of the invention, the sterilization process is performed under conditions selected to protect the functional integrity of the sterilized sensor. For example, in typical embodiments of the invention, the sterilization process is performed during or after cooling the device. In illustrative embodiments, the sterilization process is performed below a certain temperature or within a particular range of temperatures, for example below 10° C. or below 5° C. or at a temperature between 0 and 5° C., or between 0 and 10° C. In some embodiments of the invention, the sterilization process is performed under oxygen free conditions (e.g. when a formulation does not comprise an oxidizing compound). Optionally, the process is performed on a sensor within and aqueous formulation that has been de-aerated with argon gas, nitrogen gas, or the like. In some embodiments of the invention, the sterilization process is performed using a formulation having a pH below 7, below 6, or below 5 etc. In some embodiments of the invention, the sterilization process is performed under conditions selected so that the saccharide binds the saccharide binding polypeptide and/or the fluorophore quenching composition quenches the fluorophore so as to inhibit damage to the saccharide sensor that can result from the radiation sterilization process. Some methodological embodiments of the invention comprise further steps, for example those where an irradiated sensor composition comprising the aqueous radiation protecting formulation is dialyzed to alter the concentrations of one or more components in the formulation.
[0047] Another embodiment of the invention is a composition of matter comprising a saccharide sensor and a fluorophore. The saccharide sensing element of the saccharide sensor can comprise a boronic acid derivative, a molecular imprinted polymer or a polypeptide. In such compositions, the saccharide sensor is combined with a fluorophore quenching compound. One illustrative embodiment of the invention is a composition of matter comprising a saccharide sensor that includes a saccharide binding polypeptide having a carbohydrate recognition domain; and a fluorophore. In such compositions, the saccharide sensor is combined with an aqueous radioprotectant formulation comprising a saccharide, wherein the saccharide binds to the carbohydrate recognition domain. Optionally in such compositions, the saccharide sensor is also combined with a fluorophore quenching compound.
[0048] A number of compounds can be combined with the saccharide sensors disclosed herein to form the radioprotectant compositions of the invention. In typical embodiments of the invention, the composition comprises a saccharide selected from the group consisting of glucose, mannose, fructose, melizitose, N-acetyl-D-glucosamine, GluNac, sucrose or trehalose. In certain embodiment of the invention, the composition comprises a fluorophore quenching compound, for example, acetaminophen. In some embodiments of the invention, the composition comprises an antioxidant compound is selected from the group consisting of ascorbate, urate, nitrite, vitamin E, α-tocopherol or nicotinate methylester. In some embodiments of the invention, the composition comprises a surfactant, for example a polysorbate such as Tween 80. In certain embodiments of the invention, the composition comprises a buffering agent such as citrate, tris(hydroxymethyl)aminomethane (TRIS) or tartrate. Optionally the composition is formed to have a pH of 7 or below, 6 or below, or 5 or below.
[0049] Specific compounds are observed to provide saccharide sensors (e.g. those shown in FIGS. 1A-1C ) with high levels of protection against radiation damage when present in aqueous radioprotectant formulations in a particular concentration range. For example, in certain embodiments of the invention, the radiation protecting formulation comprises acetaminophen in a concentration of at least 1 mM to 50 mM (e.g. at least 10 mM, at least 20 mM, at least 30 mM, at least 40 mM etc.). Optionally, the radiation protecting formulation comprises acetaminophen in a concentration of 20 mM±10 mM (and typically ±5 mM). In certain embodiments of the invention, the radiation protecting formulation comprises sucrose in a concentration of at least 10 mM to 1000 mM (e.g. at least 100 mM, at least 200 mM, at least 300 mM, at least 400 mM etc.). Optionally, the radiation protecting formulation comprises sucrose in a concentration of 500 mM±200 mM (and typically ±100 mM). In certain embodiments of the invention, the radiation protecting formulation comprises mannose in a concentration of at least 1 mM to 100 mM (e.g. at least 10 mM, at least 20 mM, at least 30 mM, at least 40 mM etc.). Optionally, the radiation protecting formulation comprises mannose in a concentration of 50 mM±20 mM (and typically ±10 mM). In certain embodiments of the invention, the radiation protecting formulation comprises ascorbate in a concentration of at least 1 mM to 100 mM (e.g. at least 10 mM, at least 20 mM, at least 30 mM, at least 40 mM etc.). In certain embodiments of the invention, the radiation protecting formulation comprises ascorbate in a concentration of not more than 10 mM, 20 mM, 30 mM, 40 mM, 50 mM, 60 mM, 70 mM, 80 mM, 90 mM or 100 mM. Optionally, the radiation protecting formulation comprises ascorbate in a concentration of 50 mM±20 mM (and typically ±10 mM). In certain embodiments of the invention, the radiation protecting formulation comprises Tris in a concentration of at least 1 mM to 10 mM (e.g. at least 1 mM, at least 2 mM, at least 3 mM, at least 4 mM etc.). Optionally, the radiation protecting formulation comprises Tris in a concentration of 5 mM±2 mM (and typically ±1 mM). In certain embodiments of the invention, the radiation protecting formulation comprises citrate in a concentration of at least 5 mM to 100 mM (e.g. at least 10 mM, at least 20 mM, at least 30 mM, at least 40 mM etc.). Optionally, the radiation protecting formulation comprises citrate in a concentration of 10 mM±2 mM (and typically ±1 mM).
[0050] As shown by the working embodiments disclosed herein, one or more of these compounds is typically combined with another of these compounds in the radiation protecting formulations of the invention. For example, certain formulations of the invention will comprise sucrose combined with acetaminophen and/or ascorbate and/or Tris and/or citrate. Similarly, certain formulations of the invention will comprise acetaminophen combined with sucrose and/or ascorbate and/or Tris and/or citrate. Similarly, certain formulations of the invention will comprise ascorbate combined with sucrose and/or acetaminophen and/or Tris and/or citrate. Similarly, certain formulations of the invention will comprise citrate combined with sucrose and/or acetaminophen and/or Tris and/or ascorbate. The formulations can comprise additional compositions such as one or more amino acids or pharmaceutically acceptable salts, for example those disclosed in Remington: The Science and Practice of Pharmacy, University of the Sciences in Philadelphia (Ed), 21 st Edition (2005). As the sensor is to be used in the body, in typical embodiments, the excipients are commonly acceptable for use in the body.
[0051] As noted above, embodiments of the invention disclosed herein provide methods and materials useful in sterilization procedures for medical devices such as glucose sensors. While glucose sensors are the common embodiment discussed herein, embodiments of the invention described herein can be adapted and implemented with a wide variety of medical devices. As discussed in detail below, typical sensors that benefit from the methods and materials of the invention include, for example, those having sensing complexes that generate an optical signal that can be correlated with the concentration of an analyte such as glucose. A number of these sensors are disclosed, for example in U.S. Patent Application Publication Nos. 20080188723, 20090221891, 20090187084 and 20090131773, the contents of each of which are incorporated herein by reference. Embodiments of the invention described herein can also be adapted and implemented with amperometric sensor structures, for example those disclosed in U.S. Patent Application Publication Nos. 20070227907, 20100025238, 20110319734 and 20110152654, the contents of each of which are incorporated herein by reference.
[0052] The compositions used in embodiments of the invention exhibit a surprising degree of flexibility and versatility, characteristics which allow them to be adapted for use in a wide variety of sensor structures. In some embodiments of the invention, one or more sensor elements can comprise a structure formed from a polymeric composition through which water and other compounds such as analytes (e.g. glucose) can diffuse. Illustrative polymeric compositions are disclosed in U.S. Patent Publication No. 20090221891 and include, for example, material (e.g. one that is biodegradable) comprising a polymer having hydrophobic and hydrophilic units. Specific polymers can be selected depending upon a desired application. For example, for mobility of glucose, a material can be selected to have a molecular weight cut-off limit of no more than 25000 Da or no more than 10000 Da. Components disposed within such polymeric materials (e.g. sensing complexes) can be of high molecular weight, for example proteins or polymers, in order to prevent their loss from the sensor by diffusion through the polymeric materials. In an illustrative embodiment, hydrophilic units of a polymeric material comprise an ester of polyethylene glycol (PEG) and a diacid, and the molecular weight cut-off limit is affected by the PEG chain length, the molecular weight of the polymer and the weight fraction of the hydrophilic units. The longer the PEG chains, the higher the molecular weight cut-off limit, the higher the molecular weight of the polymer, the lower the molecular weight cut-off limit, and the lower the weight fraction of the hydrophilic units, the lower the molecular weight cut-off limit.
[0053] Sensor components can be selected to have properties that facilitate their storage and or sterilization. In some embodiments of the invention, all components of the sensor are selected for an ability to retain sensor function following a sterilization procedure (e.g. e-beam sterilization). In some embodiments of the invention, all components of the sensor are selected for an ability to retain sensor function following a drying procedure (e.g. lyophilization).
[0054] In illustrative embodiments of the invention, the sensor comprises a cylindrical/tubular architecture and has a diameter of less than 1 mm, 0.9 mm, 0.8 mm, 0.7 mm, 0.6 mm, 0.5 mm, 0.4 mm, 0.3 mm or 0.2 mm. Illustrative sensors of this type are shown in FIG. 1 . In certain examples, the sensor has a diameter of about 0.5 mm or about 0.25 mm. In some embodiments, the body of sensor is formed from a polymeric material. Optionally, the sensor is in the form of a fiber. In some embodiments of the invention, the internal matrix of a cylindrical sensor comprises one or more cavities or voids, for example a encapsulated longitudinal cavity.
[0055] Optionally the sensing complex produces an optical signal that can be correlated with an analyte of interest, for example, glucose. A sensing complex (e.g. one comprising a binding assay) generating the optical signal should typically be reversible such that a continuous monitoring of fluctuating levels of analyte can be achieved. Optionally, the detectable or measurable optical signal is generated using a proximity based signal generating/modulating moiety pair so that a signal is generated or modulated when a first member of the pair is brought into close proximity with a second member of the pair. In one illustrative embodiment, the analyte binding agent (e.g. a lectin such as mannose binding lectin as disclosed in WO 2006/061207) is labelled with one of a proximity based signal generating/modulating moiety pair and the analyte analogue is labelled with the other of the proximity based signal generating/modulating moiety pair, and there is a detectable difference in signal when the analyte analogue and analyte binding agent form the complex and when the analyte analogue is displaced by the analyte from the complex. Typically, the proximity based signal generating/modulating moiety pair is an energy donor moiety and energy acceptor moiety pair. Energy donor moieties and energy acceptor moieties are also referred to as donor and acceptor chromophores (or light absorbing materials) respectively. An energy acceptor which does not emit fluorescence is referred to as a quenching moiety. In such embodiments, a lectin can be labelled with one of an energy donor and energy acceptor moiety pair and the analyte analogue is labelled with the other of the energy donor and energy acceptor moiety pair. The detectable difference in signal corresponds to a detectable difference in energy transfer from the energy donor moiety to the energy acceptor moiety. Optionally, the analyte analogue bears the energy acceptor moiety and the analyte binding agent bears the energy donor moiety. In certain embodiments of the invention, the sensor of the invention incorporates an assay which generates an optical readout using the technique of fluorescence resonance energy transfer (FRET).
[0056] In one illustrative embodiment of the sensors discussed in the paragraph above, the variants of the competitive binding assay each comprise: an analyte binding agent labelled with a first light-absorbing material; a macromolecule labelled with a second light-absorbing material and comprising at least one analyte analogue moiety; wherein the analyte binding agent binds at least one analyte analogue moiety of the macromolecule to form a complex from which said macromolecule is displaceable by said analyte, and wherein said complex is able to absorb light energy and said absorbed light energy is able to be non-radiatively transferred between one of the light-absorbing materials and the other of the light-absorbing materials with a consequent measurable change in a fluorescence property of said light absorbing materials when present in said complex as compared to their said fluorescence property when said macromolecule is displaced by said analyte from said complex, and wherein the different variants of the assay are distinguished by the number of analyte analogue moieties present in the macromolecule. Such sensors are disclosed, for example in U.S. Patent Application Publication Nos. 20080188723, 20090221891, 20090187084 and 20090131773, the contents of each of which are incorporated herein by reference.
[0057] In other embodiments of the invention, the sensor comprises planar layered elements and, for example comprises a conductive layer including an electrode, an analyte sensing layer disposed over the conductive layer (e.g. one comprising glucose oxidase); and an analyte modulating layer disposed over the analyte sensing layer. In certain embodiments of the invention, the sensor electrode is disposed within a housing (e.g. a lumen of a catheter). The sensor embodiment shown in FIG. 1D is a amperometric sensor 100 having a plurality of layered elements including a base layer 102 , a conductive layer 104 which is disposed on and/or combined with the base layer 102 . Typically the conductive layer 104 comprises one or more electrodes. An analyte sensing layer 110 (typically comprising an enzyme such as glucose oxidase) is disposed on one or more of the exposed electrodes of the conductive layer 104 . A protein layer 116 disposed upon the analyte sensing layer 110 . An analyte modulating layer 112 is disposed above the analyte sensing layer 110 to regulate analyte (e.g. glucose) access with the analyte sensing layer 110 . An adhesion promoter layer 114 is disposed between layers such as the analyte modulating layer 112 and the analyte sensing layer 110 as shown in FIG. 1D in order to facilitate their contact and/or adhesion. This embodiment also comprises a cover layer 106 such as a polymer coating can be disposed on portions of the sensor 100 . Apertures 108 can be formed in one or more layers of such sensors. Amperometric glucose sensors having this type of design are disclosed, for example are disclosed, for example, in U.S. Patent Application Publication Nos. 20070227907, 20100025238, 20110319734 and 20110152654, the contents of each of which are incorporated herein by reference.
[0058] Embodiments of the invention can be used with sensors having a variety of configurations and/or sensing complexes. In certain methodological embodiments of the invention, the sensor comprises a cylindrical polymeric material having a diameter of less than 1 mm, less than 0.5 mm or less than 0.25 mm, the internal matrix comprises an encapsulated longitudinal cavity, and the sensing complex comprises a carbohydrate binding lectin (e.g. mannose binding lectin which binds glucose) coupled to a fluorophore pair. In other methodological embodiments of the invention, the sensor comprises an electrode coated with glucose oxidase and a glucose limiting membrane disposed over the glucose oxidase, wherein the glucose limiting membrane modulates the diffusion of glucose therethrough.
[0059] Various publication citations are referenced throughout the specification. The disclosures of all citations in the specification are expressly incorporated herein by reference. All numbers recited in the specification and associated claims that refer to values that can be numerically characterized can be modified by the term “about”.
EXAMPLES
Example 1
Illustrative Methods and Materials for Use with Embodiments of the Invention
[0060] Sterilization of medical devices is important and the choice of sterilization method is based on which methods would be both safe and least destructive to the medical device. Three methods of sterilization are commonly used with medical devices. These are heat sterilization, gas sterilization and radiation sterilization. Heat sterilization can be problematical for devices that include proteins because the heat can denature the proteins (protein unfolding happens at approx. 60° C.). Gas sterilization process can be difficult to use in medical devices that end up as a wet device because getting a gas into even small amounts of liquid (and out again) can be difficult. For these reasons radiation sterilization is a method of choice for use with many devices such as the glucose sensors discussed herein. Moreover, as e-beam is typically easier to control than gamma radiation, e-beam radiation is used in the illustrative examples disclosed herein. As noted below, e-beam radiation of protein containing solutions can lead to a loss of protein activity in these sensors. In addition, e-beam radiation of dyes can lead to bleaching of the dyes. Both these effects can contribute to losses in sensor activity.
[0061] In aqueous solutions, the radiolysis of water can initiate oxidation reactions of compounds dissolved in water. The treatment of aqueous solutions by electron beam irradiation can decrease the concentration of certain compounds, provided that the energy absorbed (dose) is sufficient.
[0062] During radiolysis (e.g. electron beam; eb) H2O turns into the following species:
[0063] OH., eaq, H., H3O+, H2, H2O2
[0000] H2O+ eb→[ 0.28]OH.+[0.27 ]e -(aq)+[0.6]H.+[0.07]H2O2+[0.27]H3O++[0.05]H2
[0000] (brackets show the formation of species in μmoles/J)
These entities formed by the radiolysis of water initiate many reactions with compounds present and in literature phenol degradation is often used as model compound to study the effect of the radiolysis.
[0064] The ionization of the assay components themselves in the solution is minimal compared to the radiolysis of the aqueous solvent since the concentration of assay is in the range of μM and the concentration of water will be approx. 55 M, i.e. the damaging effects of electron beam radiation to the assay origins from attack from water radiolysis products. In the optical sensor assay the protein appears in the concentration of μM i.e. water is present is 10 7 times the concentration of protein.
[0065] As discussed in detail below, a number of compounds were identified and tested to assess their ability to protect sensors against radiation damage.
Protection of Polymers
[0066] Embodiments of the invention are designed to protect sensors that comprise polymers such as PolyActive™. PolyActive™ is a biodegradable polymeric drug delivery system. PolyActive represents a series of poly(ether ester) multiblock copolymers, based on poly(ethylene glycol), PEG, and poly(butylene terephthalate), PBT.
[0067] Polymers such as PolyActive™ can be protected against radiation damages by the presence of α-tocopherol. The α-tocopherol is added to the polymer by the manufacturer and is an antioxidant (Vitamin E) often used to protect products against radiation damage. In the PolyActive polymer used in the optical sensor it is expected that the α-tocopherol predominantly will be in the lipophilic domains of the polymer.
Decoloration of Dyes
[0068] Embodiments of the invention are designed to protect sensors that comprise dyes such as Alexa Fluor® fluorescent dyes. Decoloration of dye containing water, happens when the extensive electron conjugated system of the dye molecules is destroyed. The presence of radicals in the solution can initiate this process.
Protein Degradation
[0069] Embodiments of the invention are designed to protect sensors that comprise proteins such as MBL. Radiation damages to proteins are most often initiated by the damage of the disulphide bond RSSR formed by the cysteine residues. Cysteine amino acids are the most affected amino acid by radiation. Radiation damages occur when disulfide bridges break and carbonyl groups of acidic residues lose their definition thus causing the proteins to lose their activity.
[0070] The MBL protein has cysteine rich N-terminal domains (see, e.g. NCBI Reference Sequence: NP — 000233.1). The tertiary structure of MBL is maintained by the RSSR bridges in the N-Terminal and if these are broken the structure of the protein and hence the function of the protein is lost. Wallis et al., J Biol Chem 274: 3580 (1999) shows a schematic of a polypeptide unit of MBL. In order to protect the protein from radiation damages one can endeavor to protect the cysteine residues of the N-Terminal and the CRD's.
Protection Against Radiation Damages
[0071] Art teaches that the prime species that damages proteins and other molecules in solution is the OH. (hydroxyl radical) hence this is the species to look for during protection. Antioxidants such as ascorbate can be used to protect proteins from damages by ionizing radiation. Prior art shows that the concentration of ascorbate used to protect the proteins is 0.2 M or higher, most likely due to the need for continuous antioxidant protection.
[0072] Antioxidants (e.g. ascorbate) have been described in literature for use in radiation protection of dyes. Vandat et al., Radiation Physics and Chemistry 79 (2010) 33-35 reports that electron beam irradiation induced oxidation leading to decoloration and decomposition of the dye C.I. Direct Black 22. Holton, J. Synchotron Rad. (2009), 16, 133-142 reports that ascorbate, nicotinic acid, DNTB, nitrate ion, 1,4-benzoquinone, TEMP and DTT have a protective effect against radiation damage to protein crystals. Wong et al., Food Chemistry 74 (2001) 75-84 reports the effect of L-ascorbic acid (LAA) on oxidative damage to lipid (linoleic acid emulsion) caused by electron beam radiation.
Ascorbate Action
[0073] The mechanism of action of protectants is to, for example, scavenge the radicals formed by radiolysis. The ascorbate is capable of reducing the hydroxyl radical. The ascorbate radical will undergo several processes e.g. disproportionately to ascorbate and dehydro-ascorbate (DHA). Due to this possible mode of action (ascorbate radical acting both as oxidizer and reducer) too high a concentration of ascorbate could be damaging to the chemistry of certain sensor embodiments.
Acetaminophen Action
[0074] Acetaminophen is easily oxidized in aqueous solution and hence is able to reduce radicals in solution. Since this compound also works as a fluorescence quencher for the AF594 donor fluorophore and AF700 reference fluorophore in a glucose assay system with these components, it appears that acetaminophen protects the dyes from bleaching due to its presence near the lipophilic areas of both the protein and the dyes.
[0075] Acetaminophen is more lipophilic than ascorbate and could hence act as a lipophilic radical scavenger primarily protecting the vulnerable domains (RSSR bridges and aromatic systems of the dyes) close to lipophilic domains in the compounds needing protection. This predominant lipophilic protection from acetaminophen combined with ascorbate's high solubility in aqueous solution protecting the more hydrophilic domains can be a powerful combination when looking for protection.
Sucrose and Mannose
[0076] Polyols like mannitol may be good radical scavenges and hence such carbohydrates also could yield some protection against radiation damages (hydrophilic domains). Further sucrose is known to have a stabilizing effect on the MBL hence this could help to improve the storage stability of the assay and mannose would bind to the CRD and create some stabilization effect here. Indeed carbohydrates add protective effects to the assay.
Buffer System:
[0077] Amine containing buffer systems like Tris and HEPES are known to provide some protection to the proteins. Especially they provide protection against tryptophan loss from proteins. We also observe protective effects from Tris buffer. Using Citrate as part of the buffer system keeps pH around 6 during storage. Citrate is a tertiary alcohol and alcohols like t-butanol (a tertiary alcohol) and isopropyl alcohol (a secondary alcohol) is known scavengers for radiolysis radicals.
[0078] In initial e-beam experiments, sterilization at a 15 kGy dose was used for the optical glucose sensor, one that comprises both MBL and fluorophore compositions. The conclusion was further that we would continue to identify and test excipients first for their individual protection capability and later take the best from each class and use them in combination.
[0079] The following experiments were all conducted with radiation dose of 15 kGy while the sensors were cooled and oxygen free (except when the excipient was an oxidizing compound). After radiation the performance of the sensors was evaluated. The primary parameters evaluated as being retained was the Dose Response (DR relative to 0 kGy DR) as well as the absolute DR (measured in degrees phase shift from 40 mg/dL glucose to 400 mg/dL glucose) after the 15 kGy radiation dose. Also, sensor signal drift after radiation was observed but not quantified. The first initial experiments with sterilizing unformulated sensors (control sensors not combined with any radioprotectant compositions) yielded the results shown in FIG. 2 . FIG. 2 shows a graph of data from experiments observing a retained dose response for unformulated sensors as a function of e-beam doses. The triple dose is 3×5 kGy. The sensors tested were radiated wet in a solution comprising 50 mM Tris-buffer saline.
[0080] A dose of 15 kGy as target for the radiation dose is a reasonable choice as there is still 50% retention of DR after irradiation of the unformulated fluorescent sensors. In addition the electrochemical sensors discussed herein are irradiated with 16 kGy if they have a low bioburden after production (<1.5 cfu). Due to the simplicity of the production of the optical sensor we expect this low bioburden to be the rule (and not the exception). Hence, a 15 kGy dose of e-beam is expected to provide sterility.
[0000] Tests of Excipients Useful to Protect Fluorescent Sensors from Radiation Damage:
[0081] Experiments were conducted on the fluorescent glucose sensor shown in FIGS. 1A-1C , one comprising MBL and fluorophore compounds (see, e.g. U.S. patent application publication 2008/0188723). Excipients used for protecting the sensor during e-beam sterilization processes were consequently chosen to protect MBL and these fluorophores. Dextran was considered to benefit from the protection applied to MBL. The protective excipients were chosen from the following categories:
Known MBL Binding Sugars:
[0082] Binding sugars can protect the carbohydrate recognizing domain (CRD) of the protein, by keeping the peptide structure in the right conformation. However this is not thermodynamically favored compared to non-binding sugars. ΔG=ΔH−TΔS. For binding sugars the TΔS contribution is large due to the binding sugar in the CRD being in an ordered conformation instead of the random (non-ordered) water structure in the CRD. The binding sugar will then lower the loss in ΔG less than a low binding sugar due to entropy effects.
Low-Binding Sugars:
[0083] Low-binding sugars can function to provide a more rigid hydrogen-bonding scaffold (compared to water) to support the structure of the protein during radiation.
Antioxidants:
[0084] Antioxidants are generally used as protective agents against free radical associated radiation damage. Antioxidants quench radicals by reducing them.
Oxidants:
[0085] Oxidants were tested as protective agent for the reduction of the fluorescent dyes. Radicals generated during irradiation could reduce the dyes resulting in bleaching them.
[0086] Oxidants could oxidize the dye-radicals formed thus protecting the dyes. Further in this context these compounds were trialed also to show the benefit of using antioxidants.
Amino Acids:
[0087] Amino acids are often used to stabilize pharmaceutical formulations. Both hydrophilic and hydrophobic amino acids were tested.
Surfactants:
[0088] Surfactants are often used to stabilize pharmaceutical formulations since denaturing often happens at phase transitions or boundaries.
Phenyl Compounds:
[0089] Phenyl containing compounds may stabilize the fluorescent dyes via a π-π stacking mechanism (and hence the assay).
Bacteriostats:
[0090] Bacteriostat compounds tested were phenyl containing compounds.
[0091] In the following experiments, two or more excipients were chosen from each category and tested individually and in combination with ascorbate. For the best excipients in four categories a larger matrix of experiments was trialed.
[0000] Results from Screening Round
[0092] The list of excipients tested and the concentration of each is shown in Table 1 below.
[0000]
TABLE 1
A list of tested excipients to protect our sensors during radiation.
All excipients were dialyzed into the sensor prior to irradiation.
The sensors formulated with oxidative excipients were not de-aerated
prior to radiation all other were de-aerated with Ar.
Used
Excipient
Excipients
Concentration
in combi-
Type
Used
range tested
nations 1)
Binding
Mannose
1, 2, 5, 10, 20 and 50 mM
Yes
Sugars
Fructose
50
mM
No
Melizitose
20
mM
No
Low-Binding
Sucrose
100, 500 and 1000 mM
Yes
Sugars
Trehalose
500 and 1000 mM
Yes
Antioxidants
Ascorbate
5, 50, 100 and 250 mM
Yes
Nitrite
5, 10 and 20 mM
Yes
Ureate
1 and 5 mM
Yes
α-Tocopherol
1 mg/mL (4.6 mM)
Yes
Nicotinate
20 and 50 mM
No
methylester
Oxidants
H 2 O 2
50
mM
Yes
N 2 O
Sat'd (gas bubbled through)
No
Amino Acids
Lysine
2
mg/mL
No
Tryptophan
2
mg/mL
No
Phenylalanine
2
mg/mL
No
Surfactants
Synperonic
1
mg/mL
No
Tween 20
1
mg/mL
No
Tween 80
1
mg/mL
No
“Drugs”
Acetaminophen
1, 2, 5, 10 and 20 mM
Yes
Acetylsalicylic
10
mM
Yes
acid
α-Tocopherol
1 mg/mL (4.6 mM)
Yes
Phenyl
Acetaminophen
1, 2, 5, 10 and 20 mM
Yes
Containing
Acetylsalicylic
10
mM
Yes
Compounds
acid
α-Tocopherol
1 mg/mL (4.6 mM)
Yes
Phenol
1 mg/mL (106 mM)
Yes
m-Cresol
1 mg/mL (92 mM)
Yes
Tryptophan
2 mg/mL (98 mM)
Yes
Phenylalanine
2 mg/mL
No
Nicotinate
20 and 50 mM
No
methylester
Bacteriostats
Phenol
1 mg/mL (106 mM)
Yes
m-Cresol
1 mg/mL (92 mM)
Yes
Combinations
+80
Max molarity 1M
1) The combination most often used was together with ascorbate.
[0093] The excipients listed in Table 1 were evaluated in order to choose which compounds should be used for the test of different combination of excipient. Test endeavored to identify compounds that individually had an expected protective property towards a preferred target (e.g. CRD, Dye, General peptide bond or protein and storage stabilizing effects).
[0094] Table 2 provides a brief summary of the results of the screening round. In Table 2, an overview of the excipients tested as protective agents against radiation damages during e-beam (15 kGy dose) is provided. The excipients are listed according to class of compound. Some of the excipients are listed in more than one category.
[0000] TABLE 2 Retention Range (with Excipient Type Excipients acc. DR) Best In Class Binding Mannose 47%-55% Mannose Sugars Fructose Melizitose Non-Binding Sucrose 47%-90% Sucrose Sugars Trehalose Antioxidants Ascorbate 28%-80% Ascorbate Nitrite Ureate α-Tocopherol Nicotinate methylester Oxidants H 2 O 2 38%-58% N 2 O N 2 O Amino Acids Lysine 44%-95% 1) Tryptophan Tryptophan Phenylalanine Surfactants Synperonic 26%-33% Synperonic Tween 20 Tween 80 “Drugs” Acetaminophen 10%-80% Acetaminophen Acetylsalicylic acid α-Tocopherol Phenyl Acetaminophen 10%-80% Acetaminophen Containing Acetylsalicylic acid Compounds α-Tocopherol Phenol m-Cresol Tryptophan Phenylalanine Nicotinate methylester Bacteriostats Phenol 0% N/A m-Cresol Combinations +80 50-+80%
From Table 2 we chose the following four excipients (all best in their excipient class) to be used in combination as follows:
[0095] Ascorbate: Used for general protection of the peptide bonds in proteins. In literature mentioned as the best antioxidant and yielding best protection of proteins against free radical attack. However in literature the best protection is obtained with very high concentrations of ascorbate, most often >200 mM which is at least four times the best concentration identified herein. Surprisingly, in tests of the sensor embodiments disclosed herein, it was found that using high concentrations of ascorbate (e.g. 250 mM) yields poor protection while low concentrations of ascorbate (e.g. not more than 100 mM, not more than 50 mM etc.) yields good protection.
[0096] Acetaminophen: This compound is not known to interfere with the protein in the assay. However it works as a dynamic and reversible quencher of the fluorescence from AF594. This means that acetaminophen has an effect on the AF594 and could help to protect the dye from radiation damages, e.g. prevent bleaching.
[0097] Mannose: Mannose could protect the carbohydrate recognizing domain (CRD) of the protein, by keeping the peptide structure in the right conformation.
[0098] Sucrose: Sucrose is often used for building a more rigid hydrogen-bonding scaffold (compared to water) to support the structure of the protein during radiation. Also Sucrose could bring some improved storage stability to the assay.
[0099] The list of combinations with the concentration of each excipient and the results are shown in Table 3: Table 3 shows 48 variations over the four chosen excipients that have been tested. The order of the variations is stochastic.
[0000]
TABLE 3
Excipient concentration (mM)
Dose response
Aceta-
0
15
Ascorbate
minophen
Mannose
Sucrose
kGy
kGy
Retained 1)
50
20
5
1.6
1.8
112.5%
50
20
5
500
1.1
1.6
145.5%
*50
20
1
1.8
2.1
116.7%
50
20
1
100
2.2
1.9
86.4%
*50
20
1
500
1.5
2.1
140.0%
50
10
5
1.8
1.7
94.4%
50
10
5
100
1.5
1.8
120.0%
50
10
5
500
2.0
1.6
80.0%
50
10
1
1.5
1.0
66.7%
50
10
1
100
1.8
1.4
77.8%
50
10
1
500
1.7
1.0
58.8%
50
10
1.9
1.7
89.5%
50
5
5
0.8
1.7
212.5%
50
2
2.0
1.1
55.0%
50
5
2.1
1.7
81.0%
50
5
100
1.9
1.4
73.7%
50
5
500
1.7
1.8
105.9%
50
1
1.8
1.7
94.4%
50
1
100
1.7
1.5
88.2%
50
1
500
1.8
1.8
100.0%
50
1000
2.3
1.8
78.3%
20
10
2.0
1.7
85.0%
10
20
5
1.6
1.0
62.5%
10
20
5
100
0.8
0.8
100.0%
10
20
5
500
2.2
1.2
54.5%
10
20
1
1.9
1.9
100.0%
10
20
1
100
0.9
0.8
88.9%
10
20
1
500
2.1
1.7
81.0%
10
10
5
1.3
1.5
115.4%
10
10
5
100
1.6
1.7
106.3%
10
10
5
500
1.7
1.6
94.1%
10
10
1
1.7
1.5
88.2%
10
10
1
100
1.7
1.0
58.8%
10
10
1
500
2.0
1.9
95.0%
10
5
5
1.9
1.3
68.4%
10
2
1.8
1.0
55.6%
10
5
100
1.8
1.6
88.9%
10
1
1.0
0.0
0.0%
10
1
100
1.8
1.5
83.3%
5
2
1.8
1.2
66.7%
5
1000
2.3
1.8
78.3%
20
2.2
1.7
77.3%
10
2.0
1.6
80.0%
5
2.2
1.6
72.7%
2
2.3
1.5
63.0%
1
2.4
1.3
54.2%
100
2.8
1.7
60.7%
500
1.8
1.9
105.6%
1) Retained DR >100% should not be possible but if the 0 kGy DR is unexpected low retained DR can become >100%
*High absolute DR after radiation
[0100] The plot of data shown in FIG. 3 from the SITS system shows a test run of a set of sensors that has had good protection during radiation. FIG. 3 shows a plot of phase and intensity data obtained from sensors after exposure to 15 kGy of radiation. The dose response is 1.7 after radiation compared to 2.1 before i.e. a retention of 81%. Note the long equilibration time of the sensor after startup. This most likely origins from the large concentration of sucrose used in the formulation. As is known in the art, concentrations of agents in aqueous solutions can be easily changed via processes such as dialysis.
Excipients Individual Effects
[0101] In order to get an overview of the effect of the individual excipients the results will be visualized as seen FIG. 4 . FIG. 4 shows a graph of data on DR retained for irradiated sensors as a function of Ascorbate concentration used for formulation. Too low or too high concentrations of Ascorbate used both yield low retained DR whereas the 20 mM to 100 mM concentration range yields good protection.
[0102] FIG. 5 shows a graph of data on DR retained for irradiated sensors as a function of Acetaminophen (=paracetamol, hence abbreviated PAM) concentration used for formulation. It is seen that using low concentrations of Acetaminophen yields low retained DR whereas the use of concentrations above 10 mM yields good protection. Further it is shown that adding Ascorbate to the excipients in most cases gives better protection.
[0103] FIG. 6 shows data of DR retained for irradiated sensors as a function of Acetaminophen concentration used for formulation.
[0104] FIG. 7 shows data of DR retained for irradiated sensors as a function of Acetaminophen concentration used for formulation. All sensors have contained 100 mM Sucrose and variation of additions of Ascorbate and Mannose are also shown.
[0105] FIG. 8 shows data of DR retained for irradiated sensors as a function of Ascorbate concentration used for formulation. All sensors have contained 500 mM Sucrose and variation of additions of Acetaminophen (PAM) and Mannose are also shown.
[0106] FIG. 9 shows a bar graph of data presenting the absolute DR for both radiated and non-radiated sensor as a function of formulating the sensors with Acetaminophen and Ascorbic acid.
[0107] FIG. 10 shows a bar graph of data presenting the absolute DR for both radiated and non-radiated sensor as a function of formulating the sensors with Acetaminophen, Ascorbic acid, Mannose and 500 mM Sucrose. An overall result is illustrated in FIG. 11 .
[0108] FIG. 11 shows a graph of data showing sensor response after using Tris/Citrate saline buffer+excipients. Sensors show good retention of DR.
[0109] FIG. 12 shows a graph of data presenting a direct comparison of e-beamed and non e-beamed sensors.
[0000] Buffer Impact on the Sensor Dose Response Retentions after e-Beam
[0110] Due to a demand for not degrading the polymer used on the sensor pH level needs to be around 6 during wet storage.
PBS Buffer Results
[0111] FIG. 13 shows a graph of data obtained from a native sensor tested after storage in PBS pH=5.5. The sensor itself has no problem with the PBS buffer.
[0112] FIG. 14 shows a graph of data obtained from a sensor with excipients added (500 mM sucrose, 20 mM Acetaminophen and 50 mM Ascorbate) in PBS buffer during e-beam.
[0113] FIG. 15 shows a graph of data obtained from a sensor with excipients added (500 mM sucrose, 20 mM Acetaminophen and 50 mM Ascorbate) in PBS buffer. No dose response and large drift is observed even though the sensors have not been e-beamed.
Alternative Buffers
[0114] Alternative clinically acceptable buffers are shown in Table 4.
[0000]
TABLE 4
List of optional buffers in the desired
range together with their redox state.
Primary
“Red-Ox
Buffer
pK1
pK2
pK3
amine
State”
Comment
Phosphoric
2.15
7.20
12.33
No
P = +7
+Excipients
Acid
DR Loss
Glycine
2.35
9.78
Yes
C = +3
Alanine
2.71
9.10
Yes
C = +3
Tartaric Acid
3.04
4.37
No
C = +3
Citrate
3.13
4.76
6.40
No
C = +3
Lactate
3.86
No
C = +3
Ascorbic Acid
4.17
11.57
No
C = +2
Acetic Acid
4.76
No
C = +3
Uric Acid
5.83
No
Solubility
problem
Carbonic
6.35
10.33
No
C = +4
CO 2 pressure
acid/
to keep pH
Bicarbonate
Tris
8.06
Yes
[0115] Citrate was found to be superior, and tested in up to 50 mM concentration. Citrate works OK alone but better if Tris is added:
[0116] FIG. 16 shows a bar graph of data on retained DR for using different buffer concentrations.
[0117] FIG. 17 shows a graph of data resulting from sensors using citrate only during e-beam irradiation.
[0118] FIG. 18 shows a graph of data resulting from sensors using citrate and excipients during e-beam irradiation.
[0000] Amines to Protect the Chemistry from e-Beam Damages
[0119] In certain embodiments, amines can be included in the formulations (e.g. as a good quencher of radicals). Experimental results have shown that Tris (primary amine) by itself provides protection and that this protective effect is improved when excipients are added. Illustrative amines include urea, creatine, creatin, as well as the 20 naturally occurring amino acids.
[0120] The data in this Example confirms that the effects of a single excipient as well as the effects of combinations of excipients on glucose sensor DR retention following radiation sterilization are unpredictable. In these experiments, categories of agents tested included surfactants, amino acids (hydrophilic/hydrophobic), sugars (binding/non-binding), oxidants, antioxidants, drugs, bacteriostats, and combinations of these agents. The “best-in-class” excipients appear to include ascorbate, mannose, sucrose (high concentration) and acetaminophen (low concentration). The experimental data provides evidence that combinations of excipients can protect different specific sites or functionalities of a sensor against radiation damages. Ascorbate, mannose, sucrose and acetaminophen in combination provide particularly good signal retention for sensors. Typical embodiments of the invention include a combination of two to four excipients from each group and using a combination buffer consisting of 5 mM Tris and/or 10 mM Citrate saline buffer. Some embodiments include sensor storage stability enhancing agents such as low-binding sugars (sucrose, trehalose and other polyols)
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Medical devices are typically sterilized in processes used to manufacture such products and their sterilization by exposure to radiation is a common practice. Radiation has a number of advantages over other sterilization processes including a high penetrating ability, relatively low chemical reactivity, and instantaneous effects without the need to control temperature, pressure, vacuum, or humidity. Unfortunately, radiation sterilization can compromise the function of certain components of medical devices. For example, radiation sterilization can lead to loss of protein activity and/or lead to bleaching of various dye compounds. Embodiments of the invention provide methods and materials that can be used to protect medical devices from unwanted effects of radiation sterilization.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a workpiece composite including a preform and a gel.
2. Description of Related Art
Workpiece composites containing a preform and a gel, which is accommodated in a recess of the preform, are used as pressure sensors, for example. The preform may contain a pressed screen of a printed circuit board, for example, and may be connected to a pressure sensor chip. The pressure sensor chip is positioned over a recess in the preform. The gel fills the recess and the area underneath the diaphragm of the pressure measuring chip. In general, the pressure measuring chip is bonded to the preform with the aid of an accessory agent.
Normally the gel is a passivating gel which is used as a barrier against harmful media. These are, for example, corrosive media.
However, unhardened passivating gels usually tend to creep. It is necessary to select the time period between the application of the gel and hardening to be as short as possible in order to limit areas affected by creeping to a minimum. Another option for preventing creeping is the formation of edges at which creeping stops. However, these edges may stop creeping only temporarily.
In order to prevent oils from creeping on surfaces, i.e., to prevent a surface from being wetted by an oil, it is known, for example, from published German patent document DE A 196 49 955, to coat a substrate with a fluoroalkyl-functional organopolysiloxane-containing composition. Coatings of this type are offered commercially, for example, by the Dr. Tillwich Company. Published German patent document DE A 198 47 303 describes a sensor element having an anti-adhesive surface coating. The surface coating has a compound selected from the group of the fluoropolymers, fluorormocers, polymeric fluorocarbon resins, fluorine-containing silanes, or partially fluorinated polymers.
BRIEF SUMMARY OF THE INVENTION
A workpiece composite according to the present invention contains a preform and a gel which is accommodated in a recess of the preform. The recess is enclosed by at least one edge as a creep barrier to prevent the gel from spreading. At least the edge and/or a surface surrounding the recess between the recess and the edge is provided with a coating made of an oleophobic material.
Surprisingly, it has been found that a surface which is provided with a coating made of oleophobic material also prevents the gel from creeping on this surface. The gel may thus be further prevented from creeping by the workpiece composite designed according to the present invention.
Another improvement results from providing the surfaces adjacent to the edge with the coating made of the oleophobic material.
The oleophobic material of the coating is preferably selected from the group composed of fluoropolymers, fluorormocers, polymeric fluorocarbon resins, fluorine-containing silanes, and partially fluorinated polymers. Suitable materials contained in the coating include, for example, silanes of the general formula (1)
R a —R b —Si(X) 3-n (R c ) n (1)
where R a is a perfluorinated alkyl group having 1 to 16 C atoms, preferably 6 to 12 C atoms, R b is an alkyl spacer, for example, methyl or ethyl, and R c is an alkyl group, for example, methyl or ethyl. X is a halogen, an acetoxy or an alkoxy, for example, ethoxy or methoxy, and n has the value of 0 to 2.
Silanes of the general formulas R a —R b —SiX 3 , R a —R b —Si(X) 2 Me or R a —R b —Si(X)Me 2 and their derivatives are particularly suitable, X denoting fluorine, chlorine, bromine, methoxy, ethoxy, isopropoxy, alkoxy, or acetoxy, Me denoting methyl, and Me 2 dimethyl. R a denotes perfluoro-butyl, perfluoro-hexyl, perfluoro-octyl, perfluoro-decyl, perfluoro-methyl, and R b denotes ethyl or methyl. More preferably, R a —R b — denotes 1,1,2,2-tetrahydroperfluorooctyl- or 3,3,3-trifluoropropyl.
Silanes of the general formula (R a —R b ) 2 —SiX 2 and their derivatives are also suitable, X here also denoting fluorine, chlorine, bromine, methoxy, ethoxy, isopropoxy, alkoxy, or acetoxy, R a denoting perfluoroethyl, perfluorobutyl, perfluoromethyl, and R a denoting ethyl or methyl. A suitable R a —R b radical is, for example, 3,3,3-trifluoropropyl
Suitable silanes include, for example, 1,1,2,2-tetrahydroperfluorodecyltriethoxysilane, 1,1,2,2-perfluorotetrahydrododecyltrichlorosilane, 1,1,2,2-perfluorotetrahydrododecyltrimethoxysilanes, 1,1,2,2-tetrahydroperfluorodecyltrichlorosilane, 1,1,2,2-tetrahydroperfluorodecyltrimethoxysilane, 1,1,2,2-tetrahydroperfluorodecyltriacetoxysilane, 1,1,2,2-tetrahydroperfluorodecyltriethoxysilane, 1,1,2,2-tetrahydroperfluorooctyltrichlorosilane, 1,1,2,2-tetrahydroperfluorooctyltrimethoxysilane, 1,1,2,2-tetrahydroperfluorooctyltriethoxysilane, 1,1,2,2-perfluorotetrahydrohexyltrichlorosilane, 1,1,2,2-perfluorotetrahydrohexyltriethoxysilane, 1,1,2,2-perfluorotetra-hydrohexyltrimethoxysilane, di(3,3,3-trifluoropropyl)dichlorosilane, 3,3,3-trifluoropropyltriacetoxysilane, 3,3,3-trifluoropropyltribromsilane, 3,3,3-trifluoropropyltrichlorosilane, 3,3,3-trifluoropropyltriethoxysilane, 3,3,3-trifluoropropyltrifluorosilane, 3,3,3-trifluoropropyltri-isopropoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, di(pentafluorophenyl)diacetoxysilane, di(pentafluorophenyl)dibromosilane, di(pentafluorophenyl)dichlorosilane, di(pentafluorophenyl)-diethoxysilane, di(pentafluorophenyl)difluorosilane, di(pentafluorophenyl)diisopropoxysilane, di(pentafluorophenyl)dimethoxysilane, perfluorodecyl-1H,1H,2H,2H-dimethylchlorosilane, perfluorodecyl-1H,1H,2H,2H-methyldichlorosilane, perfluorodecyl-1H,1H,2H,2H-triacetoxysilane, perfluorodecyl-1H,1H,2H,2H-trichlorosilane, perfluorodecyl-1H,1H,2H,2H-triethoxysilane, perfluorodecyl-1H,1H,2H,2H-trimethoxysilane, perfluorododecyl-1H,1H,2H,2H-dimethylchlorosilane, perfluorododecyl-1H,1H,2H,2H-methyldichlorosilane, perfluorododecyl-1H,1H,2H,2H-trichlorosilane, perfluorododecyl-1H,1H,2H,2H-triethoxysilane, perfluorododecyl-1H,1H,2H,2H-trimethoxysilane, perfluorohexyl-1H,1H,2H,2H-dimethylchlorosilane, perfluorohexyl-1H,1H,2H,2H-methyldichlorosilane, perfluorohexyl-1H,1H,2H,2H-trichlorosilane, perfluorohexyl-1H,1H,2H,2H-triethoxysilane, perfluorohexyl-1H,1H,2H,2H-trimethoxysilane, perfluorooctyl-1H,1H,2H,2H-dimethylchlorosilane, perfluorooctyl-1H,1H,2H,2H-methyldichlorosilane, perfluorooctyl-1H,1H,2H,2H-triacetoxysilane, perfluorooctyl-1H,1H,2H,2H-trichlorosilane, perfluorooctyl-1H,1H,2H,2H-triethoxysilane, perfluorooctyl-1H,1H,2H,2H-trimethoxysilane, perfluorodecyl-1H,1H-dimethylchlorosilane, perfluorodecyl-1H,1H-methyldichlorosilane, perfluorodecyl-1H,1H-triacetoxysilane, perfluorodecyl-1H,1H-trichlorosilane, perfluorodecyl-1H,1H-triethoxysilane, perfluorodecyl-1H,1H-trimethoxysilane, perfluorododecyl-1H,1H-dimethylchlorosilane, perfluorododecyl-1H,1H-methyldichlorosilane, perfluorododecyl-1H,1H-trichlorosilane, perfluorododecyl-1H,1H-triethoxysilane, perfluorododecyl-1H,1H-trimethoxysilane, perfluorohexyl-1H,1H-dimethylchlorosilane, perfluorohexyl-1H,1H-methyldichlorosilane, perfluorohexyl-1H,1H-trichlorosilane, perfluorohexyl-1H,1H-triethoxysilane, perfluorohexyl-1H,1H-trimethoxysilane, perfluorooctyl-1H,1H-dimethylchlorosilane, perfluorooctyl-1H,1H-methyldichlorosilane, perfluorooctyl-1H,1H-triacetoxysilane, perfluorooctyl-1H,1H-trichlorosilane, perfluorooctyl-1H,1H-triethoxysilane, perfluorooctyl-1H,1H-trimethoxysilane, perfluorodecyl-1H,1H,2H,2H,3H,3H-dimethylchlorosilane, perfluorodecyl-1H,1H,2H,2H,3H,3H-methyldichlorosilane, perfluorodecyl-1H,1H,2H,2H,3H,3H-triacetoxysilane, perfluorodecyl-1H,1H,2H,2H,3H,3H-trichlorosilane, perfluorodecyl-1H,1H,2H,2H,3H,3H-triethoxysilane, perfluorodecyl-1H,1H,2H,2H,3H,3H-trimethoxysilane, perfluorododecyl-1H,1H,2H,2H,3H,3H-dimethylchlorosilane, perfluorododecyl-1H,1H,2H,2H,3H,3H-methyldichlorosilane, perfluorododecyl-1H,1H,2H,2H,3H,3H-trichlorosilane, perfluorododecyl-1H,1H,2H,2H,3H,3H-triethoxysilane, perfluorododecyl-1H,1H,2H,2H,3H,3H-trimethoxysilane, perfluorohexyl-1H,1H,2H,2H,3H,3H-dimethylchlorosilane, perfluorohexyl-1H,1H,2H,2H,3H,3H-methyldichlorosilane, perfluorohexyl-1H,1H,2H,2H,3H,3H-trichlorosilane, perfluorohexyl-1H,1H,2H,2H,3H,3H-triethoxysilane, perfluorohexyl-1H,1H,2H,2H,3H,3H-trimethoxysilane, perfluorooctyl-1H,1H,2H,2H,3H,3H-dimethylchlorosilane, perfluorooctyl-1H,1H,2H,2H,3H,3H-methyldichlorosilane, perfluorooctyl-1H,1H,2H,2H,3H,3H-triacetoxysilane, perfluorooctyl-1H,1H,2H,2H,3H,3H-trichlorosilane, perfluorooctyl-1H,1H,2H,2H,3H,3H-triethoxysilane, perfluorooctyl-1H,1H,2H,2H,3H,3H-trimethoxysilane.
Particularly suitable are 1,1,2,2-perfluorotetrahydrododecyltrichlorosilane, 1,1,2,2-perfluorotetrahydrododecyltrimethoxysilane, 1,1,2,2-tetrahydroperfluorodecyltrichlorosilane, 1,1,2,2-tetrahydroperfluorodecyltrimethoxysilane, 1,1,2,2-tetrahydroperfluorodecyltriacetoxysilane, 1,1,2,2-tetrahydroperfluorodecyltriethoxysilane, 1,1,2,2-tetrahydroperfluorooctyltrichlorosilane, 1,1,2,2-tetrahydroperfluorooctyltrimethoxysilane, 1,1,2,2-tetrahydroperfluorooctyltriethoxysilane, 1,1,2,2-perfluorotetrahydrohexyltrichlorosilane, 1,1,2,2-perfluorotetrahydrohexyltriethoxysilane, 1,1,2,2-perfluorotetrahydrohexyltrimethoxysilane.
Furthermore, perfluorodecyl carboxylic acid (PFDA) and perfluorinated plasma polymers are suitable for the coating material.
The physical and/or chemical bonding of the coating to the material of the preform may be improved by an activating pre-treatment. Oxygen plasma, ozone, steam plasma, or hard UV light at wavelengths <220 nm, for example, is suitable for the activating pre-treatment.
For applying the coating, the coating material may furthermore contain at least one solvent in which the oleophobic material is dissolved or dispersed. Additives such as antifoam and fluidizing agents may also be added.
A suitable solution for applying the coating contains, for example, 0.1% to 5% 1,1,2,2-tetrahydroperfluorooctyltrimethoxysilane, 0.5% to 5% water, 0.1% acetic acid, the balance isopropanol. The solution is prepared and homogenized overnight with stirring. The solution is applied at the desired locations and, after drying at 110° C. for 30 minutes, baked in a circulating air oven.
Many of the above-mentioned silanes are utilizable directly as a solution in hydrocarbons or alcohols without any further additives for the coating. Chlorosilanes are preferably used for the gas phase deposition. In addition to solutions of the pure silanes, these silanes are also suitable for coating in a partially hydrolyzed form or in mixtures with polymers or mixtures of the individual silanes.
The coating, which is applied to the edge and/or the surface surrounding the recess between the recess and the edge, preferably has a layer thickness in the range of 1 nm to 20 μm; especially preferably the layer thickness of the coating is in the range of 1 nm to 1 μm.
In another specific embodiment, at least two edges of the preform have a stepped design as creep barriers. The two stepped edges further slow down creeping. In particular, even in the case of long dwelling times, for example, between application and hardening of the gel, creeping on the preform surface may be suppressed. Another improvement results if at least each edge is provided with the oleophobic coating.
The oleophobic layer may be applied to the preform, for example, as a paint layer or as an epilame layer. The coating may be applied, for example, by pad printing, stamping, dripping, dispensing, immersing, or spraying, as well as by CVD (Chemical Vapor Deposition) methods or PVD (Physical Vapor Deposition) methods. In the pad printing, stamping, dripping, dispensing, immersing, or spraying methods, the coating is applied using a liquid coating material; in the CVD or PVD method, the coating is applied from the gaseous phase.
After applying the coating, the surfaces that are not provided with the coating may be structured.
The coating may be applied from a solution or from the gaseous phase. Local application by stamping, spraying, dispensing, etc., is possible from a solution. From the gaseous phase, the entire component is coated; local removal of the coating is possible by applying perforated sheet metal masks and 50 Hz to 40 kHz oxygen plasma or steam plasma, by applying quartz glass masks and UV light, as well as without masking with the help of a laser.
Since, in general, components are glued to the preform, to which gel is also to adhere, preforms coated on their entire surface have the coating preferably removed again with the exception of the gel stop edges.
In a particularly preferred specific embodiment of the present invention, the recess, which is enclosed by at least one edge as a creep barrier, is sealed using a diaphragm. The diaphragm which seals the recess is preferably part of a pressure sensor chip.
The preform is preferably made of a thermoplast or duroplast, usually of LCP, PEEK, or epoxy resin. Other suitable materials for the preform are, however, also ceramics and metals.
The gel preferably contains silicones, partially fluorinated silicones, or perfluoropolyethers. The gel preferably furthermore contains substances for neutralizing corrosive or poisonous media, for example, anti-corrosion additives.
In particular when using the workpiece composite as a pressure sensor, the embodiment according to the present invention and the associated increased effectiveness of the creep barrier yield the advantage that the risk of leaks on the boundary surface between the adhesive using which the pressure sensor chip is applied to the preform and the preform is reduced. In addition, the mechanical adhesive strength of the workpiece composite in a plug housing in which it is mounted is improved.
The gel is held in position by the improved creep barrier. Minor leaks, for example, are prevented by the gel. These leaks, in particular on the adhesive of the pressure sensor chip on the preform, may result in a pressure exchange between the front and back sides of the diaphragm. This prevents the differential pressure from being correctly measured. The measuring accuracy may thus be improved by using the workpiece composite according to the present invention.
Manufacturability is also enhanced by the workpiece composite according to the present invention. Contamination from handling and manufacturing devices, for example, may thus be prevented. A more reliable protection, which is almost unlimited in time, against gel overflow by creeping also results in this way. This allows substantially longer dwelling times between the introduction of the gel and hardening to be defined, which may increase the flexibility in the manufacturing process. In addition, the workpiece composite according to the present invention also provides protection against gel overflow via mechanical introduction during handling, for example, due to vibrations, shocks, or tipping. Introducing gel into the recess in the preform also offers the advantage that the sensor cannot be damaged by icing. The contained gel prevents water from penetrating. Deposits directly on the diaphragm resulting in a characteristics curve drift are also prevented. In addition, the sensor may be installed in any position, since water is not able to penetrate. Previously, especially in applications in which water might penetrate into the sensor, it was necessary to install the sensor in such a way as to allow penetrating or condensed water to escape. Furthermore, the gel is also used for corrosion protection against basic or acidic media attacking the diaphragm.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING
FIG. 1 shows a section through the workpiece composite for a pressure sensor in a first example embodiment of the invention.
FIG. 2 shows a section through the workpiece composite for a pressure sensor in a second example embodiment of the invention.
FIG. 3 shows a pressure sensor according to FIG. 1 , which is mounted on a connection piece.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1 , a workpiece composite 1 for a pressure sensor according to a first example embodiment of the present invention includes a preform 3 , which is connected to a pressure sensor chip 5 . Pressure sensor chip 5 is attached to preform 3 using an adhesive layer 7 for this purpose.
Preform 3 is a ceramic socket or a PC board, for example. When preform 3 is a ceramic socket, Al 2 O 3 is suitable as a ceramic, for example. When preform 3 is a PC board substrate, epoxy resin materials are typically used.
Pressure sensor chip 5 is usually a semiconductor chip which has a diaphragm 9 . When there is a pressure difference between the pressures acting on the top and bottom sides of diaphragm 9 , the diaphragm is deformed. Using the deformation of the diaphragm, the pressure difference, and thus, when a pressure on one side of diaphragm 9 is known, the pressure on the other side of diaphragm 9 may be determined.
For a pressure to be able to act on diaphragm 9 on its side facing preform 3 , a recess 11 is formed in preform 3 . Recess 11 is designed as a borehole, for example. Due to recess 11 , diaphragm 9 is accessible to media also on its side facing preform 3 .
In the specific embodiment depicted here, a cavity 13 is formed between preform 3 and diaphragm 9 . However, it is also possible as an alternative that the diaphragm lies directly on preform 3 .
To protect diaphragm 9 , for example, against deposits on diaphragm 9 or condensing water, which may freeze, for example, and even at temperatures below the freezing point of water may permanently damage diaphragm 9 , recess 11 and cavity 13 are filled with a gel 15 . The side of diaphragm 9 facing preform 3 is completely covered by gel 15 . Gel 15 is a passivating gel which, in addition to preventing deposits, also provides corrosion protection against basic or acidic aggressive media. Gel 15 generally contains silicones, partially fluorinated silicones, or perfluoropolyethers. In addition, corrosion protective additives are preferably also contained in the gel.
When selecting a suitable gel 15 , particular attention must be paid to the fact that, on the one hand, it performs a protective function for diaphragm 9 but, on the other hand, the diaphragm function, i.e., the sensor characteristics and/or the electronic circuit is/are not to be negatively affected.
Recess 11 and cavity 13 are covered with the gel, for example, as described in German patent document DE-A 10 2005 056 769. For this purpose, the gel is introduced using a soft plastic needle which is inserted through recess 11 , for example. By using a soft plastic, it is ensured that the walls of recess 11 or diaphragm 9 are not damaged. A ring is conveniently used as a stop, so that the plastic needle cannot hit diaphragm 9 , damaging it. A metal ring, for example, is suitable as a ring. It preferably has a diameter that is greater than the diameter of recess 11 .
As an alternative, it is also possible, for example, to introduce gel 15 into recess 11 and cavity 13 by a vacuum dispensing method. Any other suitable methods known to those skilled in the art may also be used to add the gel.
To prevent gel 15 from creeping from recess 11 along preform 3 , recess 11 is enclosed by a first edge 17 , which acts as a gel stop edge. A surface 19 adjacent to first edge 17 is coated with an oleophobic coating 21 as a further protection against the creeping of gel 15 . Oleophobic coating 21 preferably contains a compound selected from the group composed of fluoropolymers, fluorormocers, polymeric fluorocarbon resins, fluorine-containing silanes, and partially fluorinated polymers. Polytetrafluoroethylene (PTFE) or perfluoroalkylsilanes are suitable compounds, for example.
The coating may be applied, for example, from the liquid phase or from the gaseous phase. Methods for applying coating 21 from the liquid phase include, for example, pad printing, stamping, dripping, dispensing, immersing, or spraying. Suitable methods for applying oleophobic coating 21 from the gaseous phase include, for example, CVD methods or PVD methods, but preferably CVD methods.
In the specific embodiment illustrated here, there is a second edge 23 next to first edge 17 . Second edge 23 is also used as a gel stop edge and prevents creeping, for example, when gel flows out of recess 11 or cavity 13 , for example, due to tipping or jarring, and reaches the area of surface 19 . Both surfaces forming second edge 23 are provided with oleophobic coating 21 . Bottom 25 of preform 3 , adjacent to second edge 23 , is provided with coating 21 only in the area adjacent to edge 23 .
Another advantage of second edge 23 is that, for example, roughness may occur in the area of first edge 17 , or portions of edge 17 may break off. In this case, creeping of gel 15 occurs in the area of the damage to first edge 17 , which may be further limited by second edge 23 , in addition to oleophobic coating 21 .
A workpiece composite 1 in a second specific embodiment is illustrated in FIG. 2 .
Workpiece composite 1 illustrated in FIG. 2 differs from the one illustrated in FIG. 1 by the fact that a third edge 27 , which also acts as a gel stop edge, is situated next to second edge 23 . First edge 17 , second edge 23 , and third edge 27 have a stepped design. An additional creep protection is ensured by third edge 27 , in particular with regard to jarring or tipping of workpiece composite 1 .
Also in the case of third edge 27 , as in the case of second edge 23 , both adjacent surfaces are provided with oleophobic coating 21 . Also in FIG. 2 , in the area of bottom 25 of preform 3 only the area adjacent to third edge 27 is coated with oleophobic coating 21 . After oleophobic coating 21 has been applied, it is possible that exposed surfaces, for example, bottom 25 of preform 3 , the top of preform 3 or exposed surfaces of pressure sensor chip 5 are structured. Structuring may be performed, for example, using UV light, laser, or a plasma method. When coating is removed using a plasma method, the areas containing oleophobic coating 21 preferably remain covered. A loosely placed screen may be used for covering, for example. A PC-board structure, for example, may be applied to preform 3 using structuring.
FIG. 3 shows a pressure sensor, which is mounted on a connection piece.
The pressure sensor illustrated in FIG. 3 differs from the pressure sensor illustrated in FIG. 1 by the fact that only surface 19 adjacent to first edge 17 is provided with oleophobic coating 21 . The surfaces adjacent to second edge 23 have no oleophobic coating.
Workpiece composite 1 containing pressure sensor chip 5 is mounted on a connection piece 29 . Connection piece 29 is installed, for example, on a housing containing a gas or a liquid. Such a housing may be a gas or liquid tank, for example. Workpiece composite 1 is mounted on connection piece 29 as a cover. A flange 31 , for example, is formed on connection piece 29 for this purpose. Workpiece composite 1 is attached to preform 3 via flange 31 . It may be attached using an adhesive, for example. For this purpose, an adhesive layer 33 is applied between flange 31 and bottom 25 of preform 3 . Alternatively, however, a detachable connection of workpiece composite 1 with connection piece 29 is also possible. For this purpose, workpiece composite 1 and connection piece 29 may be screwed together, for example. Clamping is also conceivable. In the case of a detachable, connection, a sealing element is preferably introduced between flange 31 of connection piece 29 and bottom 25 of preform 3 to prevent the medium, i.e., the liquid or gas contained, from flowing out from the housing or the piping on which connection piece 29 is mounted. Alternatively, gases or liquids from the environment are also prevented from penetrating into the tank or the piping, for example.
In particular if there is a positive pressure in the tank or the piping and corrosive or poisonous media are possibly contained, it is necessary to achieve a sufficient seal between preform 3 and connection piece 29 to prevent the medium from escaping.
To measure the pressure, the pressure of the medium contained in the tank or the piping acts initially on gel 15 and thus on diaphragm 9 through connection piece 29 . This pressure causes diaphragm 9 to deform, the deformation being a function of the pressure difference between the pressure in connection piece 29 and the pressure in the environment. The greater the pressure difference, the greater is the degree of deformation of diaphragm 9 . The pressure difference and thus, if the pressure in the environment is known, the pressure in connection piece 29 may be ascertained using the deformation of diaphragm 9 .
In addition to the specific embodiments illustrated in FIGS. 1 through 3 , it is also possible, for example, to position a glass plate between preform 3 and pressure sensor chip 5 . The glass plate has preferably the same peripheral geometry as pressure sensor chip 5 . A through opening is formed in the glass plate, which may also be filled with gel 15 with the glass plate installed.
In addition to its use as a pressure sensor, the embodiment according to the present invention having a gel stop edge and oleophobic coating is also suitable for any other workpiece composite in which a gel is used and creeping of the gel is to be prevented. Thus, for example, instead of a pressure sensor chip 5 , alternatively other capacitive or other sensor structures may also be used in which diaphragms are applied. Sensor structures of this type include, for example, mass flow rate sensors or microphones (dynamic pressure sensors).
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A workpiece composite includes a preform part and a gel accommodated in a recess in the preform, the recess being enclosed by at least one edge which serves as a creep barrier to prevent the gel from spreading. The at least one edge of the recess defines a termination point of at least one surface which is provided with a coating made of an oleophobic material in an area adjacent to the at least one edge.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the priority of German Application No. 197 04 815.2 filed Feb. 8, 1997.
BACKGROUND OF THE INVENTION
This invention pertains to a drawing frame for textile slivers and is more particularly directed to a device for pressing down the upper rolls onto the respective lower rolls of the drawing unit which is composed of serially arranged roll pairs formed of upper and lower rolls. The pressing device has a pressing arm which carries a force-generating device, such as a pneumatic cylinder provided with a back-and-forth movable member, such as a pressure rod for pressing the upper roll against the lower roll. Further, the upper rolls may be moved away from the lower rolls into an inoperative position.
During operation, the pressing arms are closed and the pressing devices press the upper rolls onto the associated lower rolls of the drawing unit. In case the drawing frame is at a standstill particularly for a longer time period, the pressing arms are opened to thus release the upper rolls from the pressing forces for protecting the roundness of the rolls and their elastic coating against deformation. In a known arrangement the pressing arms are pivoted open manually while the upper rolls remain stationarily positioned on the lower rolls. In case of operational disturbances, for example, if sliver is wound around the upper roll, the latter is manually lifted off its holding device against its weight and after removal of the wound loops it is preferably immediately repositioned. For inserting the slivers (in case of processing a different fiber type), for cleaning the drawing frame, for installing or removing or setting an axial pressure bar carried by the pressing arm or, in case of loop formation about a lower roll, all upper rolls have to be removed. The manual removal of particularly a plurality of upper rolls is time consuming and labor intensive. It is a further disadvantage of the prior art arrangement that particular space is required for depositing the upper rolls. It is also a drawback that the sensitive upper roll, particularly its coating, is likely to be damaged if handled carelessly.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a device of the above-outlined type from which the discussed disadvantages are eliminated and which, in a particularly simple and rapid manner makes possible an exposure of the lower rolls as well as a simple and rapid removal and replacement of the upper rolls.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the textile sliver drawing unit includes a roller assembly for advancing and drawing a sliver running therethrough. The roller assembly includes an upper roll and a lower roll cooperating with the upper roll. The drawing unit further has a pressing device for pressing the upper roll against the lower roll during operation. The pressing device includes a pivotally supported pressing arm having an inwardly pivoted operational position and an outwardly pivoted inoperative position; a force-generating device carried by the pressing arm; a movable member coupled to the force-generating device and engageable at least indirectly with the upper roll for transmitting a force from the force-generating device to the upper roll for pressing on the lower roll; and a carrier element mounted on the pressing arm and being settable into locking and unlocking positions. In the locking position the carrier element locks the upper roll to the pressing arm, whereby the upper roll is moved away from the lower roll together with the pressing arm when the latter is pivoted from the operative position into the inoperative position. In the unlocking position of the carrier element the upper roll is released from the pressing arm, whereby the upper roll remains positioned on the lower roll when the pressing arm is pivoted from the operative position into the inoperative position.
Further, by providing a settable carrier element mounted on the pressing arm, the upper roll may be lifted off its support and thereafter pivoted upwardly (that is, lifted off its associated lower roll) together with the pressing arm by means of the force-generating device (such as a pneumatic cylinder) carried by the pressing arm. In this manner, the pressing element has the combined function of pressing down on the upper rolls during operation and of lifting the upper roll from the lower roll during standstill, at which time the upper roll is automatically released from pressure by the pressing arm lifting operation. During the upward pivotal motion which follows, the upper roll remains on the pressing arm so that no separate space is needed for depositing the removed upper roll and thus damaging thereof due to a careless deposition is securely avoided and further, a substantial exposure of the lower roll is achieved. By virtue of the fact that, as an alternative, the carrier element may remain out of engagement with the upper roll, an upward pivotal motion of the pressing arm may be carried out while leaving the upper roll in its support at the associated lower roll. In such an alternative operation too, the upper roll is released from load as the pressing arm is pivoted away. In case sliver looping around an upper roll occurs, the latter may be manually lifted off its support and after removal of the sliver loop, the upper roll may again be repositioned without the need of manipulating the securing elements therefor.
The invention has the following additional advantageous features:
Each upper roll is straddled by a portal-shaped pressing arm.
Two pneumatic cylinders (force-generating devices) are associated with each upper roll.
A settable actuating lever or the like is associated with the pressure rod of the pneumatic cylinder.
The actuating lever is rotatably supported at one end thereof.
The carrier lever projects into an opening provided in a holding component for the upper roll.
The carrier lever and the upper roll may be lifted upon withdrawing the pressing rod of the pneumatic cylinder.
A setting element is associated with the carrier lever.
A pneumatic valving device is provided which has at least three switching positions.
With each pneumatic cylinder two 5/2-way valves are associated.
With each pneumatic cylinder one 5/3-way valve is associated.
With each pneumatic cylinder two 3/2-way valves are associated.
The loading force for each upper roll is individually settable by a pressure regulator.
In the pressing arm a pivotal setting element is arranged.
The pressing arm is pivotal about a joint.
A switching element, for example, a manually operable pushbutton is provided for activating the pneumatic cylinder for the carrier element.
The switching element is connected to an electronic control and regulating device and the settable position is preselected.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a drawing unit incorporating the invention.
FIG. 2a is a sectional view taken along line IIa--IIa of FIG. 1.
FIG. 2b is a view similar to FIG. 2a, showing the upper roll in a lifted position.
FIG. 3a is a front elevational view illustrating the device according to the invention, showing a downwardly pivoted pressing arm and a carrier element illustrated out of engagement with the upper roll.
FIG. 3b is a view similar to FIG. 3a showing the pressing arm in an upwardly pivoted position, leaving the upper roll in place at the lower roll.
FIG. 3c is a view similar to FIG. 3a, showing the pressing arm in an downwardly pivoted position and illustrating the carrier element in engagement with the upper roll.
FIG. 3d is a view similar to FIG. 3b showing the pressing arm and the upper roll in an upwardly pivoted position.
FIG. 4 is a front elevational view of another embodiment of the invention in which a portal-shaped pressing arm is shown in an upwardly pivoted position with the upper roll.
FIG. 5 is a view similar to FIG. 4 showing the pressing arm in an upwardly pivoted position, while leaving the upper roll in place at its associated lower roll.
FIG. 6 is a front elevational view showing details of one part of a preferred embodiment of the invention.
FIG. 7a is a schematic side elevational view of a pneumatic 5/2-way valve forming part of the structure according to the invention.
FIG. 7b is a symbolic representation of the pneumatic 5/2-way valve shown in FIG. 7a.
FIG. 8 is a block diagram of a microcomputer control and regulating device coupled to the pneumatic cylinders of the pressing arms by means of two valves.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a drawing unit forming part, for example, of an HS-model drawing frame manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Germany. The drawing unit is of the "4-over-3" type, that is, it is formed of three lower rolls I (lower output roll), II (lower middle roll) and III (lower input roll) and four upper rolls 1, 2, 3 and 4. The drawing unit drafts the sliver bundle 5 formed of a plurality of slivers and advancing through the drawing unit in the direction of the arrow C. The roll pairs formed of rolls 4 and III as well as 3 and II constitute a pre-drafting field while the roll pair formed of rolls 3 and II and the roll assembly formed of rolls 1, 2 and I constitute the principal drawing field.
The lower output roll I is driven by a non-illustrated principal motor which determines the output speed. The lower input roll III and the lower middle roll II are driven by a non-illustrated regulating motor. The upper rolls 1-4 are pressed against the respective lower rolls I, II, III by pressing devices 6, 7, 8 and 9 positioned in pressing arms 11 (only one is visible) rotatable in the direction of arrows A and B about a bearing 10. The upper rolls 1-4 are driven by the respective lower rolls I, II and III by frictional contact.
Also referring to FIGS. 2a and 2b, the lower rolls I, II and III are supported in bearing blocks 13 mounted on the machine frame 35. The pressing arms 11 also serve for shiftably receiving two pressing roll holders 14 for accommodating the upper rolls 1-4. Each upper roll holder 14 is composed of an upper part 15 and a lower part 16. The upper part 15 forms a cylinder unit having a cylinder chamber 17 in which a piston 18 is slidably received. A piston rod (pressure rod) 19 is attached to the piston 18 and is guided in a bore 20 of the upper part 15 and in a bore 21 of the lower part 16. The stub shaft 4a of the upper roll 4 projects through an opening of a holding plate 24a and is received in a bearing 22 which extends in a space 23 between the pressing roll holder 14 and the roll stub shaft of the lower roll III.
A diaphragm 25 which is in engagement with the face of the piston 18 divides the cylinder chamber 17 into an upper work chamber 17a and a lower work chamber 17b which may be selectively vented or charged with compressed air.
In operation, after a sliver bundle 5 has been positioned over the lower rolls I, II and III, the pressing arms 11 are pivoted inwardly (downwardly) into the working position illustrated in FIG. 1 and immobilized therein so that the upper rolls 1, 2, 3 and 4 may press the sliver bundle 5 against the lower rolls I, II and III. Such a pressing force is effected by the pressurization of the upper work chamber 17a of each pressing device 9, as a result of which the respective pressure rod 19--displaceable in the direction of the arrows D and E--presses down on the associated bearings 22 holding the upper rolls 1-4 which, in turn, press down on the respective lower rolls I, II, III. A carrier element formed as a slide pin 26 is mounted at an angle of 90° to the pressing rod 19 by a securing screw 28 and is shiftable in the direction of the arrows F and G relative to the pressing rod 19 by virtue of a slot 27 which is provided in the slide pin 26 and through which the securing screw 28 extends. The slide pin 26 is, at one end, supported in a bearing housing 29 which is shiftable in the direction of the arrows H, I' and in which a non-illustrated driving device is accommodated for shifting the slide pin 26. The holding plate 24a has a throughgoing opening 30 in alignment with the slide pin 26. By shifting the slide pin 26 in the direction of the arrow G, it may form-fittingly project through the opening 30.
If, as shown in FIG. 2b, a sliver loop 31 is formed about an upper roll or a lower roll, the upper roll of the roll pair where the sliver loop has been formed is shifted radially in the direction D against the resistance of the pressing rod 19 into the position 4', whereby the bearing 22 and the pressing rod 19 are likewise shifted in the direction D. At the same time a non-illustrated device for monitoring a loop formation is activated.
In FIG. 3a the pressing arm 12a is shown in a downwardly pivoted state, and the pressing rod 19 of the pneumatic pressing device 9 presses on the bearing 22. The slide pin 26 is out of engagement with the holding plate 24a. The pressing arm 12a is rotatable in the direction of the arrows K, L about a rotary bearing 32. FIG. 3b shows the pressing arm 12a in an upwardly pivoted position which it assumes after it has been swung outwardly in the direction of the arrow K. Since the slide pin 26 is out of engagement with the holding plate 24a, the upper roll 4 remains in its position at the lower roll (not shown in FIG. 3b). In FIG. 3c the slide pin 26 projects through the opening 30 of the holding plate 24a after it has been shifted in the direction of the arrow G. Thereafter the pressing rod 19 is shifted in the direction of the arrow E. Also referring to FIGS. 2a and 2b, since the slide pin 26 is connected to the pressing rod 19 by means of the screw 28 (see FIGS. 2a and 2b), the holding plate 24a, together with the upper roll 4 is also lifted in the direction E to the same extent as the pressing rod 19. At the same time, the attachment 22 1 of the bearing 22 is lifted out of the supporting extension 13a of the stand 13. Also at the same time, the housing 29, which is shiftably supported by a slide bearing 33 at the pressing arm 12a, is also displaced in the direction of the arrow N through the same extent as the pressing rod 19. Thereafter the pressing arm 12a, as shown in FIG. 3d, is pivoted outwardly in the direction of the arrow K about the rotary bearing 32. Since the slide pin 26 is form-fittingly coupled with the holding plate 24a, the upper roll 4 is, together with the pressing arm 12a, pivoted outwardly and is thus pivoted away from the lower roll. The displacement of a slide pin 26 in the direction of the arrows F, G at the other, non-illustrated end of the upper roll 4 occurs in a similar manner.
According to FIGS. 4 and 5, with each upper roll 1-4 (shown only for the upper roll 4) a portal-shaped pressing arm 12 is associated which straddles the upper roll 4. The pressing arm 12 is composed of two lateral columns 12' and 12" and a traverse 12'". At the lateral columns 12', 12" a pneumatic pressing device 9a and 9b is mounted, having respective pressing rods 19a, 19b to which carrier elements formed as levers 34a and 34b are mounted by securing screws 28a, 28b.
As shown in FIG. 4, the pressing arm 12 has been pivoted upwardly about the rotary bearing 32 supported in the machine frame 35. The levers (carrier elements) 34a, 34b project into openings of the holding plates 24a, 24b in a form-fitting manner. As a result, the upper roll 4 is also pivoted upwardly. While according to FIG. 5 the pressing arm 12 of the FIG. 4 structure is also shown in an upwardly pivoted position, the levers 34a, 34b are out of engagement with the holding plates 24a, 24b so that the upper roll 4 is not pivoted outwardly but remains in the drawing unit in its usual, operative position. It is to be understood that the other upper rolls 1, 2 and 3 are also associated with a separate pressing arm 12 which operates identically to that described in connection with the upper roll 4. At the lower end of the lateral column 12' an opening 47 is provided through which a non-illustrated shiftable locking rod extends which is mounted on the machine frame 35. The lateral column 12' further carries a key 37.
Turning now to FIG. 6, the lever 34 constituting a carrier element is at one end 34 1 rotatably jointed for pivotal motions in the direction of the arrows O, P to a rotary bearing 35' which is secured to the lateral column 12' of the pressing arm 12. The lever 34 is a single lever crank, whose two arms are oriented at an obtuse angle to one another. The other end 34 2 of the lever 34 terminates in a fork 34' through which extends a pin 28 secured to an intermediate element 36 which, in turn, is mounted on the pressing rod 19. One tine of the fork 34' has a carrier attachment (carrier element) 34" which may project into the opening 30 of the holding plate 24a (not shown in FIG. 6). If the pressing rod 19 is shifted in the direction of the arrow E, the carrier element 34 pivots about the bearing 35' in the direction P and the carrier attachment 34" is shifted in the direction E in a circular path about the center of the bearing 35'. At the same time the lever 34 rotates in the direction of the arrow P and the opening 34' moves in the direction of the pin 28 so that the carrier attachment 34" projects beyond the pin 28 as the latter slides inwardly into the fork 34'. In this manner, the carrier attachment 34" is placed in a position in which it may project into the opening of the non-illustrated holding plate for the upper roll 4 (also not shown in FIG. 6). If the pressing rod 19 is shifted in the direction of the arrow D, all motions occur in the opposite direction.
The pneumatic control of the loading (pressure-applying) device of the drawing unit is effected by means of two 5/2-way valves as shown in FIGS. 7a and 7b. Also reverting to FIGS. 2a and 4, the following three switching positions may be obtained:
A. The piston 18 is charged with pressurized air in its upper dead center, that is, the upper rolls 1-4 are lifted as shown in FIG. 4. For lifting the upper roll 1-4, before releasing a lock from the aperture 47 at the lower end of the holding column 12', a key 37 arranged on the pressing arm 12 has to be depressed. As a result, the pistons 18 are shifted upwardly and the upper rolls 1-4 are immobilized with the aid of the levers 34a and 34b. The upper rolls 1-4 may then be pivoted upwardly together with the pressing arms 12.
B. The piston 18 is charged with pressurized air in its lower dead center, that is, the upper rolls 1-4 are loaded with pressure. The loading force applied to each upper roll 1-4 may be individually set by the pressure regulator 42. Also, the pressure is monitored by a pressure switch for safety reasons.
C. The piston 18 is in its lower dead center and is depressurized (vented), that is, the pressing arms may be pivoted upwardly without the upper rolls 1-4 (as shown in FIG. 5) because the latter are not locked to the respective pressing arms. This condition is obtained automatically when the machine is at a standstill. As a result of this operation, the upper roll coatings and the material are handled gently.
Turning to FIG. 7a, in the pneumatic valve 38 a solenoid 40 is operating a 5/2-way valve 39 which has a supply air inlet nipple 39a, a first venting nipple 39b, a second venting nipple 39c, a work nipple 39d (way 1) and a work nipple 39e (way 2). The arrows show the direction of the air flow. FIG. 7b is a symbolic representation of the operation of the 5/2-way valve 39. Dependent upon the state and direction of pressurization through the work nipple 39d three switching states may be obtained. The additional work nipple 39e may be blocked or may be utilized, for example, for a pneumatic control of the slide pin 26 (shown in FIGS. 2a, 2b and 3a-3d).
FIG. 8 illustrates an electronic control and regulating device 41 (microcomputer) to which the solenoids 40', 40" of respective 5/2-way valves 39' and 39" are connected. The valves 39', 39" are coupled to respective air lines 45, 46. All pneumatic cylinders 9a-9f are coupled to both air lines 45 and 46. With this arrangement the three pneumatic switching states described above under A., B. and C may be obtained for each pneumatic cylinder 9a-9f. Further, the key 37 (FIG. 4) is also connected to the control and regulating device 41. The air line 46 is coupled to a pressure regulator 42.
It is to be understood that for obtaining the above-described three switching states, two 3/2-way valves or a single 5/3-way valve may be used as alternatives. Also, while the invention was described in connection with pneumatic pressing elements, mechanical, hydraulic or electric pressing elements may be used in the alternative for loading the upper rolls 1-4.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A textile sliver drawing unit includes a roller assembly for advancing and drawing a sliver running therethrough. The roller assembly includes an upper roll and a lower roll cooperating with the upper roll. The drawing unit further has a pressing device for pressing the upper roll against the lower roll during operation. The pressing device includes a pivotally supported pressing arm having an inwardly pivoted operational position and an outwardly pivoted inoperative position; a force-generating device carried by the pressing arm; a movable member coupled to the force-generating device and engageable at least indirectly with the upper roll for transmitting a force from the force-generating device to the upper roll for pressing on the lower roll; and a carrier element mounted on the pressing arm and being settable into locking and unlocking positions. In the locking position the carrier element locks the upper roll to the pressing arm, whereby the upper roll is moved away from the lower roll together with the pressing arm when the latter is pivoted from the operative position into the inoperative position. In the unlocking position of the carrier element the upper roll is released from the pressing arm, whereby the upper roll remains positioned on the lower roll when the pressing arm is pivoted from the operative position into the inoperative position.
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This application is a divisional of U.S. application Ser. No. 09/828,952, filed Apr. 10, 2001, now U.S. Pat. No. 6,450,182 granted Sep. 17, 2002, and claims the priority under 35 U.S.C. § 119(e) of U.S. Application No. 60/196,296, filed Apr. 12, 2000.
FIELD OF THE INVENTION
This invention relates to the field of cleaning the surfaces within pipes. The surfaces may be metal, including stainless steel. The restricted points of entry may prevent these surfaces from being cleaned by application of mechanical force or sonic energy. The contaminants to be cleaned from the surfaces include organic matter and particulates.
BACKGROUND OF THE INVENTION
The oxygen supply systems on aircraft may comprise oxygen converters, oxygen regulators, molecular sieve oxygen generators (MSOG units), oxygen pipes which are more commonly referred to as oxygen lines, and other apparatus. The cleaning of these oxygen supply systems is required primarily to remove two types of contamination. The first type of contamination arises from organic compounds. These organic compounds include jet fuel, compounds that result from the incomplete combustion of jet fuel, hydraulic oil and special types of greases that are used in these oxygen systems. The second type of contamination arises from particles of dust and dirt, as well as particles of Teflon that are found in the greases that may be used in these oxygen systems, and from Teflon tape which may be used in the threaded connections of these oxygen systems. The particulates may be in a size range of about one to 300 microns, and more commonly, in a size range of about 2 to about 150 microns.
The prior art attempts to clean oxygen lines have involved the use of chlorofluorocarbons, and have generally had unsatisfactory results. Aqueous solvents are unsatisfactory because they are difficult to remove completely and residual water may freeze and create a dangerous buildup of pressure.
There are certain requirements for methods, compositions and apparatus for cleaning the surfaces within aircraft oxygen lines to remove such contaminants. The methods should be able to be carried out in a relatively short period of time. Preferably, the cleaning should be carried out with the minimum removal of components of the oxygen system from the aircraft. The cleaning compositions should be non-aqueous, non-flammable, non-toxic, and environmentally friendly. The solvent of the cleaning compositions should be able to be used as a verification fluid that is circulated through the cleaned components in order to verify cleaning. The apparatus for cleaning should preferably be transportable to the location of the aircraft. The cleaning should achieve at least a level B of ASTM standard G93-96, which may be stated as less than 3 mg/ft 2 (11 mg/m 2 ), or less than about 3 mg. of contaminants per square foot of interior surface of the components, or less than about 11 mg. of contaminants per square meter of interior surface of the components. The method of ASTM standard G93-96 may not accurately determine the level of cleanliness in vessels with restricted entry.
There are other installations where clean oxygen lines are required. These include hospitals and physical science research facilities.
SUMMARY OF THE INVENTION
The present invention comprises methods, compositions and apparatus for cleaning the interior surfaces of pipes, and particularly, oxygen lines. These methods, compositions and apparatus have certain features in common, and other features that may be varied depending on the nature of the surfaces to be cleaned.
The present invention achieves the satisfactory cleaning of contaminants from pipes by first pulling a vacuum on the pipe to be cleaned. The pipe is then filled with a solvent, which is preferably a fluorocarbon solvent. After the pipe is filled with solvent, a cleaning solution is pumped at a high velocity through the pipe. The cleaning solution preferably comprises the fluorocarbon solvent, and a fluorosurfactant. The pipe is then rinsed with solvent. A particle counter is used to determine whether the solvent rinse contains an acceptably low number of particles. The solvent is then blown out of the pipe by a gas, such as dry air. A vacuum is then pulled on the pipe to evaporate the solvent. Subsequently, a hot dry gas is pumped through the pipe to remove any remaining solvent. The gas is preferably hot, dry air. The gas exiting from the pipe is then checked with a halogen detector to confirm that it contains an acceptably low level of solvent vapor.
DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic illustration of apparatus embodying the invention.
DETAILED DESCRIPTION OF THE INVENTION
The solvent may be selected from a number of fluorocarbons. A preferred solvent is HFE301 which is a hydrofluoroether available from 3M, and which comprises methyl heptafluoropropyl ether (C 3 F 7 OCH 3 ). A more preferred solvent is HFE-7100, which is a mixture of methyl nonafluorobutyl ether, Chemical Abstracts Service No. 163702-08-7, and methyl nonafluoroisobutyl ether, Chemical Abstract Service No. 163702-07-06. HFE-7100 generally comprises about 30-50 percent of methyl nonafluorobutyl ether and about 50-70 percent of the methyl nonafluoroisobutyl ether. A third solvent is FC-72, which is Chemical Abstract Service No. 865-42-1, and comprises a mixture of fluorinated compounds with six carbons. A fourth solvent is FC-77 which is Chemical Abstract Service No. 86508-42-1, and comprises a mixture of perfluorocompounds with 8 carbons. A preferred group of solvents comprises segregated ethers which comprise a hydrocarbon group on one side of the ether oxygen (—O—) and a fluorocarbon group on the other side.
The surfactant of the present invention may be selected from the following fluorosurfactants, or similar fluorosurfactants. The preferred surfactant is L11412 which is available from 3M, and which is a perfluorocarbon alcohol, 100% volatile, and a clear, colorless liquid, with a boiling point in the range of from about 80° C. to about 90° C. and a specific gravity of about 1.8 g./ml. A second surfactant is Krytox alcohol, which is a nonionic fluorosurfactant that comprises hexafluoropropylene oxide homopolymer. A third surfactant is Zonyl UR, which is an anionic flurosurfactant. It comprises Telomer B phosphate, which is known by Chemical Abstracts Service No. 6550-61-2. A fourth surfactant is Krytox 157FS, which is a perfluoropolyether carboxylic acid, Chemical Abstracts Service No. 51798-33-5-100.
A preferred cleaning composition comprises from about 0.001% to about 5% by weight surfactant, and more preferably from about 0.05% to about 0.5% by weight surfactant. In a preferred embodiment, there is about 0.05% by weight of the surfactant in the cleaning composition of the present invention.
The methods and apparatus of the present invention are more fully disclosed in FIG. 1 and the following description.
The apparatus of the present invention is preferably housed in a trailer or other vehicle which is parked adjacent the aircraft. An aircraft may have one or more oxygen lines. In some aircraft, there is one oxygen line for each oxygen mask that is worn by a crew member. Each aircraft oxygen line may be provided with an oxygen regulator. In practicing the invention, the oxygen regulator is typically removed from each aircraft oxygen line before it is connected to the apparatus of the present invention.
In FIG. 1, aircraft 1 is shown comprising eight oxygen lines 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 . The apparatus of the present invention comprises hose 71 which is adapted to be attached to line 72 which is the main terminus of all of the oxygen lines. Manifold 4 is provided with hoses 73 , 74 , 75 , 76 , 77 , 78 , 79 and 80 , which are adapted to be attached to the terminus of oxygen lines 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , respectively. Manifold 4 is provided with valves 2 , 3 , 33 , 34 , 67 , 68 , 69 and 70 to allow selective communication between oxygen lines 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , respectively, on the one hand, and line 39 on the other hand.
In a method according to the present invention, valve 13 in line 14 is opened. This allows concentrated surfactant from surfactant tank 15 to flow through line 14 to surfactant proportioner 16 . The concentrated surfactant may be from about 8% to about 15% by weight of the solvent. After surfactant proportioner 16 is filled with a fixed volume of concentrated surfactant, valve 13 is closed. Valve 17 in line 18 is opened, and valve 19 in line 20 is opened. A fixed volume of solvent from solvent tank 21 is pumped by a pump (not shown) through line 18 to surfactant proportioner 16 . The fixed volume of concentrated surfactant from surfactant proportioner 16 and the fixed volume of solvent from solvent tank 21 , flow through line 20 , through desiccant 22 , through filter 23 and into cleaning solution tank 24 . Valves 17 and 19 are closed. The foregoing steps may be repeated until a predetermined amount of cleaning solution is present in cleaning solution tank 24 .
Vacuum pump 25 is turned on and evacuates line 26 . Hoses 71 , 73 , 74 , 75 , 76 , 77 , 78 , 79 and 80 are attached to aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , respectively. Valve 27 is opened, while valves 2 , 3 , 33 , 34 , 67 , 68 , 69 and 70 are closed. Vacuum pump 25 is used to leak test aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 through hose 71 and lines 28 and 26 . After a predetermined level of evacuation is achieved, valve 27 is closed. Vacuum pump 25 may be turned off. Valves 2 , 3 , 29 , 30 , 31 , 33 , 34 , 67 , 68 , 69 and 70 are opened. Pump 32 is turned on. Solvent is pumped from solvent tank 21 through line 37 , through pump 32 , through lines 38 and 28 , through hose 71 , through aircraft oxygen lines 72 and 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , through hoses 73 , 74 , 75 , 76 , 77 , 78 , 79 and 80 , and through lines 39 and 35 to distillation unit 40 . After aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 are full of solvent, valves 3 , 29 , 31 , 33 , 34 , 67 , 68 , 69 and 70 are closed, and valves 41 and 43 are opened.
Cleaning solution is pumped by pump 32 from cleaning solution tank 24 , through line 42 , through pump 32 , through lines 38 and 28 , through hose 71 , through aircraft oxygen lines 72 and 5 , through hose 73 , through lines 39 and 44 , through desiccant 22 , through filter 23 and into cleaning solution tank 24 . Filter 23 should remove a substantial amount of particles. The cleaning solution is pumped by pump 32 through this continuous loop for a predetermined amount of time at a relatively high velocity. The velocity through aircraft oxygen lines 72 and 5 is preferably from about 10 to about 30 feet (about 3.0 to 9.1 meters) per second, and more preferably from about 16 to about 25 feet (about 4.9 to 7.6 meters) per second. After the cleaning solution has been pumped through this loop for a predetermined amount of time, valve 3 is opened and valve 2 is closed. After the cleaning solution has been pumped through this loop for a predetermined amount of time, valve 33 is opened and valve 3 is closed. After the cleaning solution has been pumped through this loop for a predetermined amount of time, valve 34 is opened and valve 33 is closed. After the cleaning solution has been pumped through this loop for a predetermined amount of time, valve 67 is opened and valve 34 is closed. After the cleaning solution has been pumped through this loop for a predetermined amount of time, valve 68 is opened and valve 67 is closed. After the cleaning solution has been pumped through this loop for a predetermined amount of time, valve 69 is opened and valve 68 is closed. After the cleaning solution has been pumped through this loop for a predetermined amount of time, valve 70 is opened and valve 69 is closed. After the cleaning solution has been pumped through this loop for a predetermined amount of time, valves 41 and 43 are closed, and valves 2 , 3 , 29 , 31 , 33 , 34 , 67 , 68 , 69 and 70 are opened.
Solvent is pumped by pump 32 from solvent tank 21 , through line 37 , through pump 32 , through lines 38 and 28 , through hose 71 , through aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , through hoses 73 , 74 , 75 , 76 , 77 , 78 , 79 and 80 , through manifold 4 , and through lines 39 and 35 to distillation unit 40 . The velocity of the solvent does not have to be a relatively high velocity. After aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 have been rinsed with solvent, valves 45 and 46 are opened. Pump 32 continues to pump solvent from solvent tank 21 , through line 37 , through pump 32 , through lines 38 and 28 , through hose 71 , through aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , through hoses 73 , 74 , 75 , 76 , 77 , 78 , 79 and 80 , to manifold 4 . Solvent is further pumped from manifold 4 through lines 39 and 47 , through particle counter 49 , and through lines 48 and 35 to distillation unit 40 . If the amount of particles in the solvent passing through particle counter 49 is below a predetermined level, then aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 have been cleaned. On the other hand, if the amount of particles in the solvent passing through particle counter 49 is not low enough to meet a predetermined level, then the steps of pumping cleaning solution through aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 may be repeated.
When aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 have been cleaned, pump 32 is turned off, valves 29 , 30 , 45 and 46 are closed, and valves 31 and 36 are opened. Dry air from dry air generator 50 is forced by a pump or other means (not shown) through lines 51 and 28 , and through hose 71 to aircraft oxygen line 72 . This forces the remaining solvent out of aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , through hoses 73 , 74 , 75 , 76 , 77 , 78 , 79 and 80 , through manifold 4 , and through lines 39 and 35 to distillation unit 40 . After the remaining solvent has been forced out of aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , valves 2 , 3 , 31 , 33 , 34 , 36 , 67 , 68 , 69 and 70 are closed. Valve 27 is opened. Vacuum pump 25 pulls a vacuum through lines 26 and 28 and through hose 71 , on aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 . After a predetermined level of evacuation has been achieved, valve 27 is closed, and valves 2 , 3 , 33 , 34 , 67 , 68 , 69 , 70 , 52 , 53 , and 54 are opened.
Dry air from dry air generator 50 is forced by a pump or other means (not shown) through line 55 to air heater 56 . Air heater 56 is turned on. Air heater 56 heats the dry air which is further forced through lines 57 and 28 , through hose 71 , through aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , through hoses 73 , 74 , 75 , 76 , 77 , 78 , 79 and 80 , through manifold 4 , and through lines 39 and 58 to vent 59 . After a predetermined amount of heated dry air has been forced through aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , valves 60 and 61 are opened. The heated dry air exiting from manifold 4 passes through lines 39 and 62 , through halide detector 63 , and through lines 64 and 58 to vent 59 . If the amount of halide detected by halide detector 63 is below a predetermined level, then aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 have been dried. On the other hand, if the level of halide that is detected by halide detector 63 is above a predetermined level, then additional hot dry air may be forced through aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , until the level of halide is below the predetermined level.
After the level of halide that is detected by halide detector 63 is below the predetermined level, air heater 56 is turned off and valves 2 , 3 , 33 , 34 , 52 , 53 , 60 , 61 , 67 , 68 , 69 and 70 are closed. Hoses 71 , 73 , 74 , 75 , 76 , 77 , 78 , 79 and 80 , may now be disconnected from aircraft oxygen lines 72 , 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , respectively.
Solvent may be recycled before, during or after the steps that are described above, by opening valve 66 and activating distillation unit 40 . The solution within distillation unit 40 is heated to vaporize the solvent, and the condensed solvent vapor is gravity fed through line 65 to solvent tank 21 .
Variations of the invention may be envisioned by those skilled in the art.
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The present invention is an apparatus that cleans contaminants from pipes. The apparatus comprises a high velocity pump, a cleaning solution tank, a first line that selectively connects said cleaning solution tank to said high velocity pump, a solvent tank, a second line that selectively connects said solvent tank to said high velocity pump, a manifold, and a third line that selectively connects said manifold to said high velocity pump.
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This is a continuation of U.S. patent application Ser. No. 08/681,655, filed Jul. 29, 1996, now abandoned which is a continuation of U.S. patent application Ser. No. 08/318,852, filed Dec. 29, 1994, now U.S. Pat. No. 5,540,476 which is a continuation of PCT/US92/03081 filed Apr. 15, 1992, designating the United States, which is a continuation of U.S. patent application Ser. No. 07/680,371, filed Apr. 4, 1991, now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to automobile convertible tops, and more particularly to an improved technique for attaching pliable coverings to the convertible top linkage assembly.
The present invention is well suited for convertible vehicles utilizing pliable coverings such as convertible top covers, headliners, and backlights. One common way that pliable coverings are attached to a linkage assembly is by stapling them to tack strips which are in turn fastened to the linkage assembly. Once the tack strip is attached to the linkage assembly, the staples holding the covering to the tack strip are exposed and must be covered. Accordingly, trim members are fastened to the convertible top such that the entire length of the tack strip seam is covered, however, the trim member itself protrudes above the convertible top surface and is itself a variance from the desirable smooth outer surface.
Proper installation of such a trim member involves matching the trim member with the top covering, fastening it to the linkage assembly such that it covers the tack strip seam and seats properly upon the convertible top, and finally placing end caps over the ends of the trim member to hide fasteners which hold the trim member in place. Consequently, existing methods for attaching pliable coverings require a multitude of parts, each requiring precise positioning to achieve the desirable esthetic appearance. Thus, assembly of these parts requires considerable man hours, and the removal and replacement of a damaged or defective covering requires additional man hours.
The present invention utilizes a novel bow within a convertible top linkage assembly that has a unique elongated supporting means. This elongated supporting means comprises keyhole type grooves which correspond to welts that extend from the edges of the pliable coverings. The welts slidingly engage with the grooves such that the welt is disposed longitudinally within the groove in a dovetail fashion. As a result, a seamless connection between the coverings and the linkage assembly is achieved and the welt can only be removed by sliding the covering in a direction parallel to the groove. Accordingly, the covering is securely retained and an unsightly seam that utilizes conventional fasteners is avoided. Furthermore, the time to assemble a convertible top utilizing the present invention is significantly reduced, as is the time to remove and replace damaged convertible top coverings.
Additional advantages and features of the present invention will become apparent from the subsequent description and the claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a typical convertible top with the convertible top cover, the backlight and the headliner attached in accordance with the principles of the present invention;
FIG. 2 is an exploded perspective view showing how the convertible top cover, the backlight and the headliner are interconnected by the supporting means of the present invention;
FIG. 3 is a cross sectional view of the supporting means of the present invention taken along line 3--3 in FIG. 1 showing the convertible top cover, the backlight, and the headliner engaged with the grooves in the supporting means in accordance with the principles of the present invention;
FIG. 4 is a cross sectional view similar to FIG. 3 showing an alternative supporting means in accordance with the present invention with two grooves for engagement with attaching means that extend from the convertible top cover and the backlight, in combination with a conventional headliner retainer for holding the headliner in place;
FIG. 5 is a cross sectional view similar to FIG. 3 showing another alternative supporting means in accordance with the present invention having a grooved member, with two grooves for engagement with attaching means that extend from the backlight and the headliner, riveted to a bow member having one groove for engagement with attaching means extending from the convertible top cover; and
FIG. 6 is a cross sectional view similar to FIG. 3 showing yet another alternative supporting means in accordance with the present invention having a grooved member, with one groove for engagement with attaching means extending from the backlight, riveted to a bow member having one groove for engagement with attaching means extending from the convertible top cover, along with a conventional headliner retainer attached to the bow member for holding the headliner in place.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, particularly to FIGS. 1-3, the seamless attachment of a convertible top cover 10, a flexible plastic backlight 12 and a headliner 14 to a typical linkage assembly (not shown) is accomplished by utilizing a novel bow member 16 having unique grooved supporting means. Typically, the sole function of a bow member is to support the convertible top cover 10 and the headliner 14, however, the bow member 16 of the present invention additionally provides grooves for attaching pliable coverings directly to the linkage assembly without using conventional fastening means. Furthermore, this bow member 16 can be designed to either replace a conventional bow or to be attached to an existing bow.
The bow member 16 of the present invention is preferably extruded from aluminum, however, it may also be made from other materials such as a fiber reinforced plastic material. FIGS. 2 and 3 illustrate such a bow member 16 having three grooves in accordance with the present invention. These three grooves 18, 20 and 22 are designed to individually retain corresponding attaching means that extend from the pliable coverings and engage with the grooves 18, 20 and 22. The two attaching means used to attach the backlight 12 and the headliner 14 to the bow member 16 are key-hole shaped welts 24 and 26. These key-hole shaped welts 24 and 26 are sewn with heavy stitching 27 to the edges of the backlight 12 and the headliner 14 as illustrated in FIG. 2. Note that these key-hole shaped welts 24 and 26 can be an integral portion of the backlight 12 and the headliner 14 (not shown). The welts 24 and 26 slidingly engage with the corresponding grooves 18 and 20, and by virtue of their key-hole engagement cannot be transversely disengaged from the grooves 18 and 20. To prevent the welts 24 and 26 from longitudinally disengaging from the keyhole grooves 18 and 20, small screws 25 pass through the bow member 16 and individually engage with one of the welts 24 and 26.
The other attaching means shown in FIGS. 2 and 3 is an elongated barbed member 28 which is used to attach the top cover 10 to the bow member 16. This barbed member 28 is attached to an intermediate portion of the interior surface of the convertible top cover 10 by die electric bonding 29 and reinforced by heavy stitching (not shown), however, other means such as an adhesive may be utilized. Moreover, as with the backlight 12 and the headliner 14, the barbed member 28 can integrally extend from the top cover 10. The elongated barbed member 28 has two symmetrical barbed portions 30A and 30B that extend downward from the body of the member 28. These barbed portions 30A and 30B are inserted downwardly into the corresponding groove 22 across the entire length of the barbed member 28 until the entire barbed member 28 engages with the groove 22 as shown in FIG. 3. Note that the two barbed portions 30A and 30B form a slot 32 that traverses the entire length of the barbed member 28. This slot 32 provides the necessary relief that allows the barbed portions 30A and 30B to be inserted into the groove 22. To insure that the elongated barbed member 28 does not inadvertently deflect and disengage from the groove 22, an elongated rectangular strip 34 is slidingly engaged into the slot 32.
The elongated barbed member 28 further has first and second undercut grooves 101 and 103, respectively. A substantially flat surface 105 is outwardly angled from a distal tip 107 to an enlarged portion 109 of each barbed portion 110. Thus, the leading flat surfaces 105 are inwardly angled toward each other at an end substantially opposite from a base 111. The base 111 contacts against an upper surface of the bow member 16 opposite from the undercut grooves 101 and 103. Two intermediate walls 113 project substantially perpendicular from the base 111 and the barbed portions 110 depend from the corresponding intermediate walls 113. Channel engaging portions of each barbed portion 110 are disposed outward farther than the corresponding distal end or tip 107 while the flat surface of the base 111 contacts against the external surface of the bow member 16. Furthermore, bow member 16 has differing thicknesses and at least two substantially flat external surfaces.
FIGS. 4-6 are similar to FIG. 3 and illustrate three alternate embodiments of the present invention. The embodiment depicted in FIG. 4 is a bow member 36 that has only two grooves 38 and 40; one groove 38 corresponds to an elongated barbed member 28 that extends from the top cover 10, and the second groove 40 corresponds to a keyhole shaped welt 24 that extends from the backlight 12. Unlike the previous embodiment, the headliner 14 is attached to this bow member 36 by a conventional headliner retainer 42 that is detachably affixed to the bow member 36 with threaded fasteners 44.
The embodiment depicted in FIG. 5 utilizes a bow member 46 having one groove 48 that corresponds to an elongated barbed member 28. In addition, a grooved member 50 having two grooves 52 and 54 is detachably affixed to the bow member 46 by rivets 60 or the like for supporting the backlight 12 and the headliner 14. These grooves 52 and 54 are keyhole shaped for engagement with correspondingly shaped welts 24 and 26 as discussed above.
The embodiment depicted in FIG. 6 also utilizes a bow member 56 very similar to the one depicted in FIG. 5, however, the headliner 14 is attached to this bow member 56 with a conventional headliner retainer 42 that is detachably affixed to the bow member 56 using threaded fasteners 44. Furthermore, the backlight 12 is supported by a grooved member 58 that is detachably affixed to the bow member 56 using rivets 60 or the like. This grooved member 58 has one keyhole shaped groove 62 for engagement with a correspondingly shaped welt 26 that extends from the backlight 12 as discussed previously.
Although the invention has been described and illustrated in connection with certain preferred embodiments there are many variations and modifications that can be effected within the spirit and scope of invention, therefore the invention as set forth in the following claims is not to be limited to the precise details of construction set forth above.
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A convertible top having improved supporting means (16, 36, 46, 50, 56 and 58) for securing pliable covering (10, 12, and 14) to the linkage assembly. The means for securing the pliable covering (10, 12 and 14) includes one or more grooves (18, 20 and 22) on the supporting means (16, 36, 46, 50, 56 and 58) and attaching means (24, 26, 28) on the pliable covering (10, 12 and 14) which engages a groove (18, 20 or 22) in the supporting means (16, 36, 46, 50, 56 and 58) to secure the pliable covering (10, 12 and 14) in place. A method of assembly is also disclosed.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of International PCT Patent Application No. PCT/US2009/056390, which was filed on Sep. 9, 2009, now pending, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/095,337, filed Sep. 9, 2008, which applications are incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a process for recovering hemicellulose from Arundo donax.
[0004] 2. Description of the Related Art
[0005] The world today is facing growing burdens caused by overpopulation, depletion of fossil fuels, increasing demands for fuels, pollution of air, water and land, global warming and climate changes, forest cover destruction, and agricultural land loss. Although to some extent some of these concerns can be met through the improved use of solar energy and windpower and increased nuclear power, more conservation of resources and more efficient use of resources are always being sought.
[0006] Fibrous cellulosic material, such as straw, corn stalks (stover), bagasse, hardwoods, cotton stalks, kenaf and hemp, are composed primarily of cellulose (typically, 40-60% dry weight), hemicellulose (typically 20-40% by dry weight) and lignin (typically 5-25% by dry weight). These components, if economically separated fully from one another, can provide vital derivative sources of fermentable sugars for the production of alcohols, ethers, esters and other chemicals. There is a growing interest in the manufacture of biofuels from cellulosic biomass by fermentation with enzymes or yeast. To date, the majority of that interest has focused on the use of starch, cane and beet sugar. As used herein, biofuels refers to fuel (ethanol) for the generation of electricity and for transportation. Biofuels are beneficial in that they add fewer emissions to the atmosphere than petroleum fuels. They also are beneficial in that they use herbaceous and sparsely used woody plants and, particularly, plant wastes that currently have little or no use. Biofuels are obtained from renewable resources and can be produced from domestic, readily available plants and wastes, thus reducing dependence on coal, gas and foreign fossil fuel in addition to boosting local and world-wide economies.
[0007] To date, however, there has not been an economical method for cleanly separating the basic components of fibrous, ligno-cellulosic materials and the fermentable sugars they represent from one another. In particular, it has proved difficult to economically separate the mixed hexose and pentose structured hemicellulose from the lignin and other, minor, components, such as lipids and silica, present in biomass. The processes which exist today focus on techniques such as ball-milling, two-roll milling, cryogenic grinding, explosive depressurization, ultrasonics and osmotic cell rupture followed by ethanol extraction, as well as conventional pulping techniques. All use high levels of technology, fossil energy and investment and, accordingly, are expensive and, often, highly polluting. For example, conventional pulping processes, which use high temperatures (e.g., 175° C.) and pressure (e.g., 175 psi) and sulfite, kraft or alkali to obtain purified cellulose, known as alpha pulp, are well recognized as involving high investment, energy and operating costs, including recovery of chemicals, which are accompanied by severe problems of air and water pollution and the production of toxic materials.
[0008] Accordingly, although there have been advances in the field, there remains a need in the art for alternative cellulosic biomass materials and alternative methods for fractionating cellulosic biomass materials. The present invention addresses these needs and provides further related advantages.
BRIEF SUMMARY OF THE INVENTION
[0009] In brief, the present invention is directed to processes for recovering hemicellulose from Arundo donax , separating the lignin and other extractives (e.g., plant extractives), and hydrolyzing the purified hemicellulose containing extract (or fraction) to a mixture of 5 and 6 carbon sugars at sufficiently high concentration for fermentation and/or hydrogenation treatments. As disclosed herein, recovery of hemicellulose and its separation from lignin and other extractives depends on minimizing hemicellulose side reactions during extraction and on retaining the hemicellulose material in a high molecular weight form (i.e., large size) during subsequent purification and concentration steps prior to conversion to 5 and 6 carbon sugars.
[0010] Due to its high biomass productivity, Arundo donax is a potentially economically viable source of pulp, as well as bioethanol and bio/petrochemical replacements such as 3 to 6 carbon glycols. All of these are in very high demand as a result of national moves to “green” products and of increased crude oil costs. As described in more detail below, prior to conventional pulping processes or as part of nonconventional pulping conditions described herein, a portion of the Arundo donax plant hemicellulose fraction may be recovered and converted to 5 and 6 carbon sugars using the disclosed integrated processes comprising various hemicellulose extraction, purification, concentration and hydrolysis steps. The 5 and 6 carbon sugars obtained according to these processes may be marketed to existing manufacturing facilities for further fuel and chemical production. While similar individual process steps have been used separately in other industries, integration and development of appropriate process conditions is required for this combination of raw material and products.
[0011] In one embodiment, a process for extracting a hemicellulose containing fraction from an Arundo donax biomass is provided, comprising treating the Arundo donax biomass in an aqueous solution at a temperature in the range of 40-130° C. and at a pH in the range of 5-12 for ½-5 hours. In certain embodiments, the Arundo donax biomass comprises Arundo donax chips.
[0012] In certain embodiments, the process yields an extracted Arundo donax biomass. In other embodiments, the process yields an Arundo donax pulp.
[0013] In certain embodiments, the aqueous solution comprises hydrogen peroxide. For example, in more specific embodiments, the aqueous solution comprises 0-10% by weight hydrogen peroxide (e.g., 0-5% by weight hydrogen peroxide).
[0014] In certain embodiments, the aqueous solution comprises sodium hydroxide. For example, in more specific embodiments, the aqueous solution comprises 0-12% by weight sodium hydroxide.
[0015] In certain embodiments, the temperature is in the range of 40-105° C. In other embodiments, the temperature is in the range of 45-130° C.
[0016] In certain embodiments, the temperature is in the range of 40 to less than 90° C., the Arundo donax biomass is treated for ½-1½ hours and the process yields an extracted Arundo donax biomass. In other embodiments, the temperature is in the range of 90-100° C., the Arundo donax biomass is treated for 1-3 hours and the process yields an Arundo donax pulp. In other embodiments, the temperature is in the range of 100-130° C., the Arundo donax biomass is treated for ½-1½ hours and the process yields an Arundo donax pulp.
[0017] In certain embodiments, the hemicellulose containing fraction comprises 10-40% by weight hemicellulose.
[0018] In a second embodiment, an integrated process for recovering hemicellulose from Arundo donax is provided, comprising: (a) extracting a hemicellulose containing fraction from an Arundo donax biomass as set forth in the embodiments above; (b) purifying the hemicellulose containing fraction to remove lignin and other extractives; (c) concentrating the purified hemicellulose containing fraction; and (d) hydrolyzing the concentrated and purified hemicellulose containing fraction to yield a 5 and 6 carbon sugar containing fraction.
[0019] In certain embodiments, steps (b) and (c) comprise a single purification and concentration step.
[0020] In certain embodiments, the process further comprises: (e) purifying the 5 and 6 carbon sugar containing fraction to remove any remaining lignin and other extractives; and (f) concentrating the purified 5 and 6 carbon sugar containing fraction.
[0021] These and other aspects of the invention will be evident upon reference to the following detailed description and attached drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0022] FIG. 1 is a schematic diagram of a first representative Arundo donax hemicellulose recovery process of the present invention.
[0023] FIG. 2 is a schematic diagram of second representative Arundo donax hemicellulose recovery process of the present invention.
[0024] FIG. 3 is a schematic diagram of a third representative Arundo donax hemicellulose recovery process of the present invention.
[0025] FIG. 4 is a schematic diagram of fourth representative Arundo donax hemicellulose recovery process of the present invention.
[0026] FIG. 5 shows hemicellulose extracted as a function of temperature, time, alkali and peroxide charge.
DETAILED DESCRIPTION OF THE INVENTION
[0027] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the invention. However, one skilled in the art will understand that the invention may be practiced without these details. In other instances, well-known structures and methods associated with pulping processes have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments of the invention.
[0028] Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is as “including, but not limited to”.
[0029] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0030] Arundo donax is one of highest known biomass producing plants. As disclosed in U.S. Pat. No. 6,761,798, Arundo donax may be used to produce pulps, paper products and particle board. In addition, and as disclosed herein, the high bioproductivity of this species may provide the basis for production of various biobased petroleum replacements.
[0031] FIGS. 1-4 are schematic diagrams of representative Arundo donax hemicellulose recovery processes of the present invention. For purposes of illustration assume a biomass production of 20 dry tons of leaf/sheath free chips per acre-year. Using conventional pulping conditions, this will yield about 9 tons of pulp while about 11 tons of dissolved plant material appears in process black liquor. This dissolved organic material comprises a complex mixture derived from degradation of a portion of the hemicellulose and lignin originally present in the biomass. However, conventional pulping chemistry alters the hemicellulose and produces non-sugar degradation products that may not be used to produce fermentation ethanol or useful petroleum replacement chemicals. Thus, separation and recovery of useful hemicellulose and related simple sugars directly from this black liquor is not feasible using existing conventional techniques.
[0032] As disclosed herein, a portion of the hemicellulose may be extracted from an Arundo donax biomass prior to conventional pulping ( FIGS. 1 and 2 ). Alternatively, as part of the hemicellulose extraction process, an Arundo donax pulp may be produced as part of a new non-conventional mild pulping process described herein ( FIGS. 3 and 4 ). In either case, the extracted hemicellulose containing fraction is rich in soluble hemicellulose oligomers, as well as soluble lignin and other plant extractives. This extract stream may be used for production of ethanol or for a range of petrochemical replacements described later. In addition, as further disclosed herein, careful selection of the extraction conditions permits economical recovery of a hemicellulose rich liquid contaminated with relatively small amounts of lignin and plant extractives. After removal of the soluble (e.g., low molecular weight) lignin and extractives, the hemicellulose is hydrolyzed to simple 5 and 6 carbons sugars that may be subsequently fermented to ethanol or hydrogenated to a blend of glycols. The market for the former as a fuel additive is extremely large and the demand for the latter is huge since these are potential fuel additives and amount to about ¼ of the total mass of products such as polyesters and polyurethanes.
[0033] By limiting this extraction to ¼ to ⅓ of the total available hemicellulose, the extracted chips are easier to pulp by conventional pulping processes and will produce a pulp with equal properties and yield as obtained from non-extracted chips. Alternatively, the new non-conventional mild pulping process described herein may be used to produce pulp appropriate for selected paper products, while also yielding a hemicellulose containing fraction comprising about ⅔ hemicellulose and ⅓ lignin appropriate for recovery of simple sugars as disclosed herein.
[0034] Based on the above assumptions (i.e., 20 dry tons of leaf/sheath free chips per acre-year), the liquid extract stream will contain a total of about 2.0 tons of hemicellulose, lignin and extractives per acre per year. Following lignin/extractive removal, about 1.6 tons of usable hemicellulose derived sugars could be sold for fermentation or hydrogenation. As one of skill in the art will appreciate, production of ethanol or chemicals must be preceded by lignin and extractives removal. Accordingly, after purification and hydrolysis to simple sugars, the foregoing quantity of hemicellulose should produce about 0.5 ton of ethanol (by fermentation) or 1.5 tons of mixed 5 and 6 carbon sugars that could be sold to a sugar hydrogenation facility.
[0035] Again, for purposes of illustration and using the foregoing estimates, a plantation of 100,000 acres of Arundo donax could provide sufficient raw material for simultaneous production of about 900,000 tons of pulp, 16 million gallons of fuel ethanol and 300 million pounds of mixed glycols.
[0036] While similar processes to the required steps in a process sequence for hemicellulose recovery have been demonstrated elsewhere on other types of wood and non-wood furnishes, the steps disclosed herein have never been used in an integrated process sequence as shown in FIGS. 1-4 . In addition, each Arundo donax furnish derives from different soil, meteorological and agronomic conditions and is different in composition and in the chemical structure in ways that will affect extraction conditions. Furthermore, the presently available purification and concentration methods of the liquid streams containing lignin, hemicellulose and related 5 and 6 carbon sugars is complex and expensive to implement. While membrane processes offer a potentially less expensive way to accomplish these two steps, conditions for the two membrane steps needed to be developed. The purification (removal of lignin and plant extractives) and concentration (removal of water and dissolved inorganic salts) steps require selection of membranes with the appropriate pore size distribution and operating conditions.
EXAMPLES
[0037] As noted above, the integrated process of the present invention comprises a sequence of steps including chip extraction, extract purification and extract concentration, hemicellulose hydrolysis, and further purification of the 5 and 6 carbon sugar extract, followed by the possible sale to third parties for fermentation or hydrogenation of the resulting 5 and 6 carbon sugar mixture.
Extraction Conditions to Maximize Hemicellulose Recovery while Retaining Acceptable Pulp Properties
Range of Chip Extraction Conditions
[0038] Wet or air dried Arundo donax chips are treated in the temperature range of 40-130° C., pH range of 5-12 and with and without addition of hydrogen peroxide. Quantities of extracted hemicellulose, simple 5 and 6 carbon sugars, sugar acids, lignin and plant extractives are measured at each extraction condition. These temperature and pH ranges span the ranges at which the disclosed process is feasible without unacceptable material product property loss. The presence and absence of peroxide indicates the extent to which that oxidant will stabilize hemicellulose against peeling and yield losses by conversion to undesirable sugar acids. It also shows the impact of a mild oxidant on ability of this system to produce soluble, low molecular weight, lignin even at these mild processing conditions. The efficiency of any downstream hemicellulose purification system (discussed in the purification and concentration steps described below) depends on the ability to maintain the hemicellulose at the highest MW possible and produce soluble lignin at low MW. Finally, the comparison of results on dried and never dried chips provides guidance for harvesting and storage requirements related to chemical recovery and pulping operations.
[0039] Experimental—Extraction Step
[0040] a. Raw Material
[0041] Whole plant material harvested at any time later than about three months after onset of growth was fractionated into stem and leaf fractions for purposes of treatment to produce a hemicellulose rich extract. The stem fraction was chipped to produce chips with dimensions approximately ⅛ to 2 inches in width and ½ to 6 inches in length. Thickness of the chips were the normal thickness of the plant stem wall, amounting to about ⅛ to ½ inch depending on the age at time of harvest and on the vertical location in the stem from which the chips originated. The leaves were separated and mechanically shredded into pieces approximately ½ by ½ inch.
[0042] b. Procedure/Conditions
[0043] Chip Fractions. The Arundo donax stem chip fractions prepared as described above were extracted using the following range of conditions:
[0044] Liquid/chip ratio=3/1 to 10/1
[0045] 2 to 20% by weight alkali (NaOH) based on oven dry chip weight
[0046] 0 to 10% by weight hydrogen peroxide based on oven dry chip weight
[0047] 40-130° C.
[0048] ½ to 5 hours
[0049] These extractions were performed under atmospheric or slightly pressurized conditions up to approximately 130° C. using a batch reactor of 10 liter capacity. As one of skill in the art will appreciate, extractions could also be made at larger scale in any type of batch or continuous reactor. For example, in a single mixed tank or a series of connected tanks equipped to continuously supply and remove chips and extraction liquor. In the series configuration liquor and chips could move in co-flow or in counter-flow configuration. Alternatively, a continuous reactor could be configured as a tube with internal flights to move chips from one end of the tube to the other end while submerged in the extraction liquor. Liquor and chips could move in co-flow or in counter-flow configuration.
[0050] Leaf Fractions. The Arundo donax leaf fractions prepared as described above were treated under the following range of conditions:
[0051] Liquid/chip ratio=3/1 to 10/1
[0052] 2 to 20% alkali (NaOH) based on oven dry chip weight
[0053] 0 to 10% hydrogen peroxide based on oven dry chip weight
[0054] 40 to 105° C.
[0055] ½ to 5 hours
[0056] c. Extraction Results
[0057] The results from extraction runs using the Arundo donax stem chips are set forth in the following Table 1.
[0000]
TABLE 1
Peroxide
NaOH
(% on
Temp.
Extract
Run No.
(% on O.D)
O.D)
(° C.)
Time (hrs)
Yield (%)
1
10
5
90
2
11.1
2
10
5
90
1
14.0
3
10
5
52
4
14.0
4
10
5
90
1
14.8
5
5
5
90
1
8.8
6
5
5
90
1
9.2
7
2
5
90
1
5.4
8
10
5
57
2
10.0
9
2
5
52
2
5.0
10
10
0
90
2
14.0
11
5
5
56
2
5.3
12
10
5
55
1
9.0
13
5
0
57
1
6.7
14
5
0
56
2
7.3
15
3
5
50
2
5.9
16
3
0
53
2
6.3
17
10
5
106
1
11
18
5
5
47
2
7.9
19
10
5
92
1
12.2
20
10
5
92
1
10.1
21
10
5
92
1
10.6
22
10
5
90
1
11.0
23
10
5
90
1
11.6
24
12
5
110
1
15.0
25
12
5
110
1
15.1
26
10
5
110
1
14.5
27
10
5
120
1
15.3
28
10
5
130
1
19.1
[0058] These results show that in the range of 40 to 130° C., 1-4 hours, 2 to 10% alkali and 0 to 10% peroxide from about 5 to 19% of the dry plant material can be extracted. As further shown, more severe conditions, as represented by higher alkali and peroxide concentration, higher temperature and longer time, result in greater extract yield. The soluble extracted solids are comprised of about ⅔ carbohydrate and ⅓ lignin. FIG. 5 shows the calculated hemicellulose recovery as a function of process temperature with time, alkali and hydrogen peroxide charges as parameters.
[0059] The results from extraction runs using the Arundo donax leaf fractions are set forth in the following Table 2.
[0000]
TABLE 2
P
Cook
NaOH
(% on
Temp.
Time
Extract
Run No.
(% on O.D)
O.D)
(° C.)
(hrs)
Yield (%)
1
Water/pH 6.5
20.56
2
3
5
55
1
10.43
3
Water/pH 6.5
23.97
4
3
5
55
1
8.5
Integration of Extraction and Pulping
[0060] Since one advantage of the present invention is the maximization of extraction recovery while simultaneously maintaining pulp properties, integration of the extraction and pulping steps was needed. In order to accomplish this, pulping rate, yield and pulp properties for chips extracted at the optimal conditions were determined in the ranges shown in FIG. 5 and any necessary adjustments of the extraction and the pulping conditions are made. For example, it has been found that in various embodiments, an Arundo donax pulp may be produced by treating the Arundo donax chips in the temperature range of 90-100° C. for 1-3 hours or 100-130° C. for ¼-1½ hours.
[0061] The results from integrated extraction and pulping runs using the Arundo donax stem chips are set forth in the following Table 3.
[0000]
TABLE 3
Extraction
Extract
Pulp
Pulp Tear
Pulp Burst
Run
NaOH
Peroxide
Temperature
Time
Yield
Yield
Index
Index
No.
(% on O.D)
(% on O.D)
(° C.)
(hrs)
(%)
%
mN*m 2 /g
kPa*m 2 /g
1
10
0
90
2
14
86
2.9
1.3
2
10
5
90
2
14.8
85.2
3.4
1.4
3
10
5
90
2
14
86
3.2
1.4
4
10
5
92
1
12.2
87.8
3.1
1.2
5
10
5
92
1
10.1
89.9
3
1.3
6
10
5
92
1
10.6
89.4
3
1.3
7
10
5
90
1
11
89
3.1
1.3
8
10
5
90
1
11.6
88.4
3.7
1.4
9
20
10
95
2
41.5
58.5
6.4
2.3
10
15
10
95
1.5
17.8
82.2
4.4
1.6
11
20
10
95
1
48.6
51.4
6.8
2.2
12
20
10
95
2
44.3
5.9
2
13
10
5
95
3
15.9
84.1
3.9
1.5
14
10
5
106
1
11
89
3.3
1.4
15
12
5
110
1
15
85
3.9
1.5
16
12
5
110
1
15.1
84.9
4.1
1.5
17
10
5
110
1
14.5
85.5
3.9
1.5
18
10
5
120
1
15.3
84.7
4.4
1.6
19
10
5
130
1
19.1
80.1
4.7
1.7
Purification of the Hemicellulose Rich Extract
[0062] There are two methods for low cost hemicellulose purification. First, since hemicellulose has a relatively high molecular weight (≈25,000 to 200,000) and soluble lignin and plant extractives have a relatively low molecular weight (≈250 to 6,000), membranes with a pore size or cut off size between these ranges permit fairly efficient separation of the high and low MW fractions. For example, commercially available ceramic membranes (such as ultrafiltration membranes available from Pall Corporation) permit separation of narrow MW fractions at low operating cost. These membranes tolerate much more aggressive reverse flow cleaning cycles and can be thoroughly cleaned by heating in muffle furnaces. Accordingly, the membrane life is very long compared to polymer based membranes.
[0063] Second, commercial systems are available for acidification and filtration of the resulting precipitated lignin. This type of system is simple and inexpensive, but depending on the lignin properties may be difficult to operate. Furthermore, the extractives which are very deleterious to downstream sugar fermentation or hydrogenation will remain with the hemicellulose and must be removed by a separate operation.
Purification of the Hemicellulose Rich Extract (i.e., Lignin, Extractive Removal)
[0064] Small scale membrane test equipment is used to select the correct membrane pore size for separation of impurities from the hemicellulose fractions generated as described above and to confirm that the separation is feasible. Performance efficiency is measured by the fraction of total available hemicellulose rejected by the membrane and the fraction of available lignin and plant extractives passed through the membrane.
Production of Sufficient Purified Hemicellulose for Fermentation and Hydrogenation Testing
[0065] The downstream fermentation and the hydrogenation steps can tolerate some amount of lignin and plant extractive impurities. Accordingly, for economic reasons, complete purification is not necessary. To determine the quantity of impurities that can be tolerated, purified hemicellulose products containing three different amounts of those impurities are generated. These products are then hydrolyzed to the simple 5 and 6 carbon sugar mixtures and subjected to fermentation testing. The rate of conversion to ethanol, the extent of inhibition by impurities present and the total yield of ethanol or byproducts are measured.
[0066] Experimental—Purification Step
[0067] Extracts prepared as described in the extraction step noted above are processed in membrane ultrafiltration to produce a membrane retentate stream rich in higher molecular weight, polydisperse hemicellulose fraction (MW≈10,000 to 300,000) and a membrane permeate stream rich in lower molecular weight, alkali soluble, polydisperse lignin (MW≈500 to 5000). The chemical composition, average molecular weight and the molecular weight range of the feed stream depends on Arundo donax agronomic conditions, on age at harvest and on the conditions used in the extraction step noted above. Accordingly, membrane pore size and ultrafiltration operating conditions vary with the source and treatment of the feed. The operating conditions fall in the following range:
[0068] Feed stream: 3 to 35% total solids
[0069] Temperature: 25 to 50° C.
[0070] Membrane molecular weight cut off (MWCO): 1000 to 300,000
[0071] Pore size for the above MWCO correspond to: 0.0015 to 0.035 micron
[0072] Operating pressure: 0.5 to 5 bar
Concentration of Hemicellulose to about 20% Solids
[0073] Rates of fermentation and hydrogenation and the final yield of either ethanol or glycols blends are directly affected by the concentration of the mixed sugar feed. Typically the results are maximized and the operating costs minimized at 20 to 25% solids in the feed stream, the best operating conditions must be determined for each situation.
[0074] Experimental—Concentration Step
[0075] The hemicellulose rich retentate streams recovered in the purification step noted above are concentrated to 10 to 35% total solids content using membrane ultrafiltration with a membrane pore size selected to produce a retentate stream rich in polydisperse hemicellulose fractions and a permeate stream consisting primarily of water and low molecular weight inorganic and organic solute species. The optimum pore size for this concentration step depends on the extraction conditions and on the conditions used in the purification step noted above (both affect the molecular weight of the recovered polydisperse hemicellulose and the pore size required to retain that material while passing the lower molecular weight material through the membrane). The operating conditions for this step fall in the ranges:
[0076] Feed stream: 3 to 35% total solids
[0077] Temperature: 25 to 50° C.
[0078] MWCO: 10,00 to 30,000
[0079] Corresponding pore size: 0.0015 to 0.0044
[0080] Operating pressure: 0.5 to 5 bar
Integrated Purification and Concentration of the Hemicellulose Rich Stream
[0081] Commercial systems are available for evaporative concentration of conventional pulping liquors. Furthermore, other systems have been developed for lignin removal. However, these systems in the present processes can not be used for several reasons. In conventional alkaline pulping systems, the hemicellulose portion of the plant material becomes largely depolymerized producing a complex mixture of chemically modified structures (termed saccharinic acids) that are totally separated from the soluble lignin fraction. These chemical species are too highly modified to be useful for either fermentation or hydrogenation processes. That lignin can then be precipitated by acidification. The resulting precipitate has been isolated by gravity settling or by filtration of the insoluble lignin. This type of system is simple and inexpensive, but the gelatinous, hydrophilic lignin plugs normal filtration media and resists dewatering in either filtration or in settling systems. As a result, these systems are difficult to operate, would be difficult to adapt for practical lignin and hemicellulose separation in the system described herein and have limited practical use for large scale processing.
[0082] Furthermore, the biomass treatment conditions described herein are intentionally selected to retain the hemicellulose structure as high molecular weight oligomers. As a result of these mild conditions, chemical interactions between the lignin and the hemicellulose prevent precipitation of soluble lignin from precipitating.
[0083] Consequently, new combinations of process steps have been developed that will permit inexpensive concentration of process streams by water removal and the separation of the soluble lignin from hemicellulose derived 5 and 6 carbon sugars. The resulting concentrated and purified sugar mixtures can be used for fermentation or for further chemical processing such as hydrogenation to produce mixtures of simple glycols.
[0084] The mild extraction conditions described above result in soluble lignin and hemicellulose oligomers with much different chemical and physical behavior than in conventional pulping processes. Unlike conventional processes these soluble lignin and hemicellulose oligomers are dissolved with minor chemical modification and enter the soluble state as large macromolecules. These large structures are easily retained by membranes of appropriate pore size allowing water, soluble plant extractives and inorganic salts to pass the membrane into the permeate. These macromolecules have a unique and limited tendency to form gelatinous deposits on and near the membrane—solution interface. The paucity of gelatinous deposits permits rapid water removal (concentration) and plant extractive and inorganic salt removal (purification) with far less membrane pluggage and any associated required cleaning cycles or membrane replacement than for similar materials derived from normal high temperature extraction/pulping processes.
Range of Conditions for Concentration of the Hemicellulose Rich Extract (i.e., Water, Extractive and Inorganic Salt Removal)
[0085] Membrane test equipment is used to select the range membrane pore size for appropriate for concentration of the lignin/hemicellulose fractions generated in the extraction step described above. Performance efficiency is measured by the final concentration of retentate, the initial and final permeate flux per unit area and time, the retention of lignin and hemicellulose, the reduction in permeate resin/fatty acid content and its conductivity resulting from transfer of inorganic salts into the permeate.
[0086] Experimental—Concentration Step
[0087] a. Raw Material
[0088] Liquid containing material extracted from Arundo donax as prepared in the extraction step described above and containing dissolved lignin, hemicellulose and plant extractives is treated for removal of water (concentration), resin/fatty acid and soluble inorganic salts. The change in total solids content demonstrates degree of water removal, titration of retentate and permeate measures resin/fatty acid separation and trends in conductivity of permeate indicates transfer of inorganic salts into the permeate. The chemical composition, average molecular weight and the molecular weight range of the feed stream will depend on A. donax agronomic conditions, on age at harvest and on the conditions used in the extraction step described above. Accordingly, as one of skill in the art will appreciate, membrane pore size and ultrafiltration operating conditions will vary with the source and treatment of the feed. Membranes ranging in porosity from about 300 to 30,000 Dalton vary in recovery and in flux rate for this application.
[0089] b. Conditions and Results
[0090] The liquid extract feed prepared in the extraction step noted above contained 2.83% total solids of which 63% amounted to hemicellulose, 30% lignin, 2% resin and fatty acids, 5% inorganic sodium salts and a conductivity of 12,700 micro Siemens per centimeter. This liquid feed was concentrated to about 23% solids using five different filter media ranging in pore size from “tight”, 250 dalton nanofilters to “open” 30,000 dalton ultrafilters.
[0091] The nanofilters and ultrafilters shown in Table 4 ranged in pore size from about 250 Daltons to about 30,000 Daltons and were constructed of various polymeric materials. The complex interaction between soluble macromolecules and the filter media leading to rejection of material or acceptance into the permeate depends heavily on the ratio of pore size opening to swollen, soluble molecule size and to the interaction of the molecules with the particular filter media chemistry. Nanofilters 1-3 and ultrafilters 1-2 increased in pore size. The small pore sizes require higher operating pressure to produce reasonable permeate flows. The permeate contained more solids and higher conductivity as a result of the more material passing through the more open membranes. The most “open” ultrafilter passed nearly all of the small inorganic salts into the permeate since the conductivity was about the same as the feed. All nanofilters produced a colorless permeate containing no lignin so all of that material was rejected by those filters and remained in the retentate. The larger pores of the ultrafilters passed small amounts of the colored lignin into the permeate. All filters passed the resin acid/fatty acid feed content into the permeate since none of that material remained in any retentate.
[0092] Finally, the average permeate flux rate was similar for all filters despite the large difference in filter pore size between the tight (nanofilter 1) and the open (ultrafilter 2) filters. This similarity in flux rate despite the wide range in pore sizes relates to the tendency of macromolecules to enter and plug those pores that are larger than the molecules. As a result, despite the large ultrafilter pore sizes, the flux rate did not increase significantly. The optimum membrane will depend on the amount of lignin and inorganic salt contamination that can be accepted by downstream processing requirements such as fermentation and hydrogenation. For this application, the nanofilter 3 may provide the optimum flux rate/inorganic acceptance/colored lignin rejection.
[0000]
TABLE 4
Example Membrane Dewatering and Purification of Extraction Liquids
Average
Permeate
Flux
Pressure
Solids
Conductivity
Membrane
(gfd*)
(psig)
(%)
(mS)
Color
Nanofilter 1
90
200
0.25
3500
colorless
(270 Dalton,
polyamide)
Nanofilter 2
70
200
0.46
6000
colorless
(300 Dalton,
thin film, non-
polyamide)
Nanofilter 3
88
200
0.53
6500
colorless
(500 Dalton,
thin film, non-
polyamide)
Ultrafilter 1
70
100
1.18
9800
very light
(polyethersulfone)
color
Ultrafilter 2
100
100
1.78
13,000
light color
(regenerated
cellulose)
*gfd means gallon per square foot per day
Hydrolysis of Hemicellulose to 5 and 6 Carbon Sugars
[0093] Experimental—Hydrolysis Step—Method 1
[0094] The purified and concentrated hemicellulose stream derived from the foregoing steps is a polydisperse polymer mixture containing mainly the five and six carbon xylose, glucose, mannose and arabinose sugar structures in the polymer chain with relative quantities of about 90, 6, 3, 1 respectively depending on the biomass source and on the conditions in the foregoing steps. The concentrated stream is treated with a mixture of enzymes consisting of xylanase, cellulase, beta glucosidase and mannonase enzymes that acts to break glycoside between these sugars in the polymer chain and releases xylose, glucose, mannose and arabinose sugars respectively. This action results in a concentrated aqueous solution (at approximately the same solids concentration as the feed to this hydrolysis step) mixture of these sugars appropriate for sale to a third party.
[0095] Since hemicellulose composition varies with the raw material and with conditions employed in Steps 1 and 2 the proportion of enzyme used for this hydrolysis step will vary and must be adjusted with each situation. The conditions fall in the following ranges:
[0096] Reaction time: 1 to 10 hours
[0097] Mass ratio of enzyme/s to sugar/s: 1/5 to 1/50
[0098] Temperature: 45 to 55° C.
[0099] pH: 4.6 to 5.4
[0100] Experimental—Hydrolysis Step—Method 2
[0101] A standard condition of 120° C. at pH 4.5 for one hour converts all hemicellulose in these liquid streams into a mixture of 5 and 6 carbon sugars at about 99% yield. The ratio of pentose to hexose sugars depends on the type of biomass feed stock. For Arundo donax , the ratio amounts to about 9/5/3/2 of xylose/glucose/galactose/mannose. Xylose is a 5 carbon sugar while the others are 6 carbon sugars.
Purification and Concentration of 5 and 6 Carbon Sugar Mixtures
[0102] Rates of fermentation and hydrogenation and the final yield of either ethanol or of glycol blends are directly affected by the concentration of the mixed sugar feed. Typically, the results are maximized and the operating costs minimized at 20 to 25% sugar solids in the feed to those processes. Recovery and concentration of simple 5 and 6 carbon sugars from the foregoing steps involves two sequential operations. First, the sugars are separated from the lignin contained in the product of the foregoing step producing a highly purified, sugar rich permeate at from 5 to 15% total solids. Second, this stream is concentrated to about 20-30% solids as preparation for marketing to fermentation or to chemical processing customers.
[0103] The small size sugars (low molecular weight) are readily separated from larger molecular weight lignin using the membranes shown in Table 3. Lignin rejection from the permeate is 100% with about 95% sugar recovery in the permeate at flux rates of about 10 gpd. Water removal from the resulting sugar rich permeate requires membranes falling in the reverse osmosis pore size range (30-150 dalton).
[0000] Operating Conditions and Results from Concentration of the Sugar Rich Permeate
[0104] A raw material solution derived from the hydrolysis step and containing 2.2% mixed sugars was concentrated to 20% total solids using two reverse osmosis membranes of 30 and 40 Daltons, respectively, but made with different chemical composition. The average flux rates were 90 and 150 gfd respectively. The higher flux rate of the latter is a result of different interaction between feed and membrane chemistry. Despite the “tight” reverse osmosis pore size membrane, flux remained nearly constant for an extended period indicating that virtually no pore pluggage occurred in this application and suggesting potentially very long operating times with little down time for membrane cleaning or replacement.
[0105] While particular steps, elements, embodiments and applications of the present invention have been shown and described herein for purposes of illustration, it will be understood, of course, that the invention is not limited thereto since modifications may be made by persons skilled in the art, particularly in light of the foregoing teachings, without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
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The present invention relates generally to a process for recovering hemicellulose from Arundo donax comprising extracting a hemicellulose containing fraction from an Arundo donax biomass, purifying the hemicellulose containing fraction to remove lignin and other extractives, concentrating the purified hemicellulose containing fraction, and hydrolyzing the concentrated and purified hemicellulose containing fraction to yield 5 and 6 carbon sugars.
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FIELD OF THE INVENTION
The present invention generally relates to an improved pinch valve construction which can be used in any type of pipeline, including a line with substantially zero pressure or gravity flow therein.
DESCRIPTION OF THE PRIOR ART
Typically, a pinch valve arrangement includes a valve sleeve. The valve sleeve includes a tubular elastomeric section, generally cylindrical in construction, and opposed flanges at opposite ends of the tubular section. The flanges are fastened to adjacent sections of a pipeline.
A mechanical actuator causes a movable pinch bar or other pinching element to compress the tubular sleeve section by flattening it against a fixed pinching element, thereby adjustably controlling the flow of material through the sleeve.
Normally, a pinch valve sleeve is made from pure gum rubber, neoprene, BUNA, butyl, hypalon, urethane, viton, EPT (nordel), silicone, or food grade rubber.
Pinch valve constructions as generally described herein have been used in controlling the flow of, by way of example, solids in suspension (either in slurry or air-conveying form), abrasive materials such as metallic ores, asbestos fibers, sand, coal, sugar, wood chips, pulp, paper stock, plastic pellets, raw sewage, talc, cement, fly ash, various chemicals and foodstuffs.
While the aforementioned pinch valve construction is extremely useful in various situations, it is not entirely satisfactory when the sleeve section has been compressed or flattened for any length of time. In that event, the sleeve section tends to become set in the flattened position and remains closed even when the movable pinching element is moved away from the fixed pinching element due to the tendency of the elastomeric material to creep and solidify when kept under external compressure forces over time. The known pinch valves are particularly unsatisfactory when used in pipelines having no gravity flow or in which the materials to be conveyed are at substantially zero pressures. In such low pressure pipelines the sleeves have a marked tendency to become set in the flattened configuration.
Once a sleeve has become set, the desired flow through the entire pipeline is no longer capable of being controlled. It is frequently necessary to replace the entire pinch valve, thereby resulting in high maintenance costs and a relatively short working life time for the pinch valve.
SUMMARY OF THE INVENTION
1. Purposes of the Invention
It is an object of the present invention to provide an improved pinch valve construction which overcomes the aforementioned drawbacks of the prior art.
Another object of the present invention is to provide an improved pinch valve construction wherein the pinch valve sleeve is forced back into its original configuration as the movable pinching element is withdrawn.
A further object of the present invention is to provide an improved pinch valve construction which is particularly suitable for use in a pipeline with little or no pressure or gravity flow therein.
2. Brief Description of the Invention
According to the present invention, the foregoing as well as other objects, are accomplished by an improved pinch valve construction which includes an elastomeric pinch valve sleeve having an elongated central flow-through passage. The pinch valve construction includes a movable pinching element and a fixed pinching element, both elements being juxtaposed opposite wall portions of the pinch valve sleeve. In a preferred embodiment, an endless loop extends circumferentially around the peripheries of the fixed pinching element, the valve sleeve, and the movable pinching element. The loop is of such circumferential length that there is substantially no slack in it when the valve sleeve has been flattened upon movement of the movable element towards the fixed element.
In normal use, the pinch valve sleeve is closed by means of the movable pinching element urging the sleeve in one direction against the fixed pinching element, thereby flattening the sleeve and restricting the material flow through the passage. As the movable pinching element is moved in the opposite direction, the endless loop exerts pressure on additional wall portions of the flattened sleeve, thereby restoring the sleeve to its original configuration and permitting increased material flow through the passage of the sleeve.
Alternatively, portions of two cables are embedded in opposed wall portions of the pinch valve sleeve with the first projecting ends of the two cables extending circumferentially around the periphery of the movable pinching element and attached to each other and with the second projecting ends of the cables extending circumferentially around the periphery of the fixed pinching element and attached to each other.
The invention accordingly resides in, inter alia, the features of construction, combination of elements, and arrangement of parts which will be exemplified in the device hereinafter described and of which the scope of application will be indicated in the appended claims. However, the invention, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the descriptions of the accompanying drawings and the specific embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings wherein like parts are given the same reference numerals:
FIG. 1 is an elevation view of a pinch valve construction according to the prior art showing a valve sleeve in section remaining set in a somewhat flattened configuration although the movable pinch bar has been withdrawn;
FIG. 2 is an elevation view of a pinch valve construction according to a first embodiment of the present invention showing the valve sleeve in section and in a fully open configuration;
FIG. 3 is a sectional view taken substantially along line 3--3 of the embodiment of FIG. 2;
FIG. 4 is a sectional plan view taken substantially along the line 4--4 of the embodiment of FIG. 3;
FIG. 5 is an elevation view analogous to FIG. 2 according to the first embodiment showing the valve sleeve in section and in partially open, i.e. somewhat flattened, configuration; and
FIG. 6 is an elevation view of a second embodiment of a pinch valve construction according to the present invention showing the valve sleeve in section and in a fully open configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, FIG. 1 shows a pinch valve construction 10, according to the prior art, having a valve housing member 12. Guide rods 14 and 16 are attached to the valve housing member 12 and to a fixed valve member 18. Both valve member 18 and housing member 20 extend between the spaced guide rods 14,16 in parallel relationship to each other. A movable valve member 20 is attached to flow control means including a drive shaft 22, which passes through a passage formed in the valve housing member 12. The movable valve member 20 is mounted on the guide rods 14 and 16 for sliding movement lengthwise of the latter between the valve housing member 12 at one end region of the guide rods and the fixed valve member 18 at the other end region of the guide rods. An elastomeric pinch valve sleeve 24 having a central flow-through passage 26 is located between the movable valve member 20 and the fixed valve member 18. The valve sleeve 24 is attached by conventional means to adjacent non-illustrated sections in a pipeline.
In operation of the prior art device, in order to restrict the flow of material through the passage 26, the movable valve member 20 is urged by flow control means 22 towards the fixed valve member 18, thus compressing the sleeve 24 and forcing it to assume a generally flattened configuration; i.e., the cross-sectional area of the flow-through passage 26 has been decreased. In another phase of operation of the prior art device, movable member 20 is moved by flow control means 22 away from the fixed valve member 18, thus relieving pressure on the compressed sleeve 24 and permitting the valve sleeve 24 to resume its original configuration; i.e., the cross-sectional area of the flow-through passage 26 has been increased to permit less restricted flow of material therethrough.
However, the elastomeric material of which the prior art valve sleeve is composed, for example, gum rubber, neoprene, or food grade rubber, tends to creep and flow and then to solidify and harden when compressed for any substantial length of time. In other words, the valve sleeve 24 takes a compression set whose effect is magnified when flow control means 22 has not moved the movable valve member 20 away from the fixed valve member 18 for a long period of time.
As shown in FIG. 1, when the prior art valve sleeve 24 has taken a compression set it will not resume its original configuration even after the movable valve member 20 has been moved away from the fixed valve member 18, and thus the flow of material through the passage 26 remains restricted. This problem is especially acute when the valve is used in a pipeline with substantially zero line pressure or gravity flow as there is insufficient internal pressure on the inner circumferential valve sleeve wall portions in such a line to urge the sleeve back into its original configuration.
In FIGS. 2-5, an improved pinch valve construction 28 according to a first embodiment of the present invention is shown, and includes a valve housing member 30. Guide rods 32 and 34 are attached to the valve housing member 30 and to a fixed member 36 which extends in mutually parallel relationship relative to housing member 30. A movable valve member 38 is attached to flow control means or drive shaft 40 which passes through a passage provided in the valve housing member 30. The movable valve member 38 is mounted for sliding movement on the guide rods 32 and 34 lengthwise of the latter between the valve housing member 30 at one end region of the guide rods and the valve member 36 at the other end region of the guide rods.
A pinch valve sleeve 42, best seen in FIG. 3, having an elastomeric tubular section or main body portion preferably but not necessarily of one piece with a pair of end flanges 46 and 48 is located between the movable valve member or pinch bar 38 and the fixed valve member or stationary pinch bar 36 as shown in FIG. 2. The elastomeric tubular section 44 comprises a pair of lateral wall portions 50 and 52, and an additional pair of opposed wall portions 54 and 56, all of the wall portions 50,52,54 and 56 together bounding a flow-through passage 58. The tubular section 44 is constituted by elastomeric materials such as pure gum rubber, neoprene, BUNA, butyl, Hypolon, urethane, viton, EPT (nordel), silicone or food grade rubber. The pinch valve sleeve 42 is attached in conventional manner to adjacent nonillustrated sections of a pipeline by means of the end flanges 46 and 48, which may be constituted by any shape-retaining material such as metal, synthetic plastic material, or resilient elastomeric material and may be attached to the adjacent nonillustrated pipe sections by bolting, welding, soldering, or any other analogous fastening technique.
In accordance with the invention, a restoring means 60 comprising an elongated restoring element whose ends are connected by a suitable fastening means 78 to form an endless resilient loop, for example a band or filament of spring steel, extends circumferentially around the peripheries of the movable valve member 38, the tubular valve sleeve section 44, and the fixed valve member 36, as shown in FIGS. 2-4. Portions of the loop 60 engage the lateral wall portions 50 and 52 of the tubular sleeve section 44. The endless loop 60 is of such circumferential length that there is substantially no slack in it when movable valve member 38 is moved towards fixed valve member 36 to a position nearly adjacent to the latter.
In operation, in order to restrict the flow of material through the passage 58, the movable valve member 38 is urged by flow control means 40 towards the fixed valve member 36, thus compressing the sleeve 42 as shown in FIG. 5 and forcing the opposed wall portions 54 and 56 of tubular valve sleeve section 44 to approach each other, as well as decreasing the effective cross-sectional area of the flow-through passage 58 and restricting the flow of material therethrough.
In order to open the valve passage 58, the movable valve member 38 is moved by flow control means 40 away from the fixed valve member 36 as shown in FIG. 2, causing the endless loop 60 to exert pressure on the lateral wall portions 50 and 52 directed inwardly towards the center of the tubular sleeve section 44. The inward pressure exerted by the loop 60 on the lateral wall portions 50 and 52 increases as the pressure exerted on the opposed wall portions 54 and 56 by the valve members 36 and 38 is decreased by the withdrawal of the movable valve member 36, thus overcoming the tendency of the elastomeric tubular valve sleeve section 44 to remain set in a flattened configuration. The tubular sleeve section 44 is forcibly restored to its original open configuration by the action of the endless loop 60, thereby permitting resumption of unrestricted flow of material through the valve passage 58.
Another preferred embodiment of the present invention is shown in FIG. 6 which is analogous to FIG. 2, and in which parts which correspond to parts in FIG. 2 are given corresponding primed numerals. In this second preferred embodiment, the restoring means 60' comprises two restoring elements or cables 62 and 64 composed of a resilient material such as spring steel. An insert portion 66 of the cable 62 is embedded in the lateral wall portion 50' of tubular valve sleeve section 44' with two offset end portions 68 and 70 of the cable 62 projecting outwardly beyond the tubular sleeve section 44'. An insert portion 72 of the cable 64 is similarly embedded in the lateral wall portion 52' of the tubular sleeve section 44' with two offset end portions 74 and 76 projecting outwardly beyond the tubular sleeve section 44'. The projecting end portion 68 of the cable 62 and the projecting end portion 74 of the cable 64 extend around the periphery of the movable valve member 38' and are fastened to each other by a suitable fastening means 78', for example a clamp or weld joint. In a like manner, the projecting end portion 70 of the cable 62 and the projecting end portion 76 of the cable 64 extend around the periphery of the fixed valve member 36' and are fastened to each other by an analogous fastening means 80.
As will be apparent to those skilled in the art, the pinch valve construction just described is particularly suitable for adjustably controlling the flow of material through a pipeline, even in a line with substantially zero pressure or gravity flow, because the tendency of the elastomeric valve sleeve to take a compression set when kept in a flattened position over time is overcome by the action of the restoring means hereinabove described. The unrestricted flow of material through the valve sleeve may be resumed at the desired time merely by moving the movable valve member away from the fixed valve member.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
For example, the restoring means 60 or 60' need not be a single loop, but may instead comprise several turns of a winding. Restoring means 60 or 60' need not be constituted by spring steel, but any resilient or slightly resilient metal or synthetic plastic material may be employed. With particular reference to restoring means 60', the cables 62 and 64 need not have any portions thereof embedded in the tubular section 44', but they may instead be adhesively or otherwise secured to the tubular section 44'.
While the invention has been illustrated and described as embodied in a pinch valve it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit for the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
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An improved pinch valve construction comprises a pair of pinch bars spaced apart of each other, and a valve sleeve intermediate the pinch bars and having wall portions bounding a flow-through passage. A flow-control device moves the pinch bars towards and away from each other and is operative for urging the sleeve from an open configuration in which the wall portions are spaced apart at a pre-determined distance to thereby permit flow through the passage, towards a flattened configuration in which the wall portions are spaced at a distance less than the predetermined distance to thereby restrict flow through the passage. A restoring device urges the sleeve from the flattened configuration towards the open configuration, whereby any tendency of the sleeve to remain in the flattened configuration when the pinch bars are moved away from each other is counteracted.
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BACKGROUND OF THE INVENTION
This invention relates to die blades for use with extrusion dies of the type adapted to produce sheets of a thermoplastic polymer. It relates particularly to blades adapted for use in extrusion processes where it is important to maintain a careful control over the thickness of the extruded sheet.
The extrusion of a polymer between the lips of a sheet die gives a superficially uniform product but if the gauge is monitored, minor thickness variations are often found in the cross machine direction as well as in the direction of extrusion. These can be caused by uneven lip separation along the slit, differential temperatures within the polymer melt such that the amount of swell that occurs as the polymer exits the slit varies, or the presence of minor inhomogeneities in the melt.
It is often important to produce a polymer sheet of great gauge uniformity so that the resolution of this problem of gauge variation can be a very significant commercial goal.
DISCUSSION OF THE PRIOR ART
The earliest approach to gauge control was to provide that one of the die lips be moveable in response to the adjustment of a plurality of jack-bolts located along its length so as to control the separation between the opposed lips. This approach however leaves a substantial time lapse between the identification of the gauge variation problem and its correction. Moreover, the adjustment is a matter of trial and error and needs much experience on the machine with specific polymers before it can be done with any degree of efficiency.
One solution to this control problem is to control the temperature of the die lip along its length so as to provide that perceived thickness variations can be corrected by increasing or decreasing the die lip temperature, and hence that of the polymer melt in contact therewith, in the region of the thickness variations. This approach is exemplified in U.S. Pat. No. 3,819,775.
An alternative, mechanical approach is to provide that at least one of the lips is flexible to the extent it can be locally deformed by physical pressure to provide local adjustment of the die gap. This approach was shown in U.S. Pat. No. 2,938,231 in which the jack bolts conventionally used to adjust the die gap thickness were elongated and provided with heater mechanisms such that activation of the heater mechanism associated with a bolt caused the bolt to expand and locally deform the flexible lip thus narrowing the slit at that point.
This approach was refined in U.S. Pat. No. 3,940,221 which added to the earlier device a cooling means associated with each bolt so as to permit adjustment by contraction as well as expansion of the bolt and therefore a more rapid response to the need for adjustment. One specific problem encountered with such gauge control devices is that of "stick-slipping", that is the tendency to resist the expansion forces and then, when a resistance threshold has been overcome, moving suddenly by an amount that may well be excessive if only fine adjustment is needed. This problem is a serious limitation on the utility of such devices.
All the above systems can be linked by computer-based systems to a downstream gauge monitoring device so as to bring about an automatic, corrective actuation of the heating means to correct any perceived gauge variation. This means that the gauge control can be completely automated in a highly efficient manner.
However, such techniques have the disadvantage that the spacing of the adjustment points is limited by the dimensions of the bolt and its associated heating and cooling means. Additionally the stick-slipping problem described above places limitations on the speed by which the device can respond accurately to a need for adjustment.
DESCRIPTION OF THE INVENTION
A new die blade has now been designed for use in the extrusion of thermoplastic polymer sheets of very closely controlled gauge. A die incorporating the die blade of the invention is capable of responding rapidly to any perceived gauge variations in such a way as to eliminate them. The die blade of the invention does not require the somewhat bulky expandable bolts that in some cases render it impossible to have the adjustment points as close together as would otherwise be desired.
The adjustment technique is usually at least as responsive to the alternatives and is capable of application to existing extrusion apparatus with little in the way of structural modification.
A slit die incorporating the die blade of the invention is one in which local adjustment of the die gap is achieved by providing means for generating expansion and contraction forces in the body of the die blade while providing heat barrier means to minimize the effect of temperature variations on the temperature of the die blade lip.
This can be done by providing a plurality of temperature adjustment means disposed within the body of the blade in aligned, spaced relationship along its length and, disposed between the temperature adjustment means and the die blade lip, a heat barrier means adapted to maintain the die blade lip at a constant temperature.
The function of the temperature adjustment means is to generate local heating or cooling in the die blade so as to produce local expansion or contraction tending to deform the die blade lip. This tendency is reinforced by the fact that the blade is usually bolted to the die block adjacent the edge opposed to the lip, thus limiting expansion in that direction.
The provision of the heat barrier means ensures that the temperature variations generated by operation of the temperature adjustment means do not affect the temperature of the blade in the area in which it is in contact with the extruding polymer.
The temperature adjustment means can be located in the body of the die blade as shown in FIGS. 1 and 2 and can operate upon any suitable basis such as for example the use of a circulating fluid or by the use of electrical heating or a combination of any such means. One embodiment of such an adjustment means is a passage formed in the body of the die blade through which a heated fluid can be circulated. By adjusting the temperature of the fluid, perhaps by a mixing technique or by actuation of appropriate heating and cooling means, the temperature of the block in the immediate vicinity of the means can readily be adjusted. Another alternative is to provide that the temperature adjustment means be provided by an electrical heater device that may, if desired, be associated with a passage through which a cooling fluid can be circulated to accelerate cooling of the adjacent portion of the block when the current is removed from the heater.
It is often preferred that adjacent temperature adjustment means be insulated from one another to avoid the tendency to dissipate the expansive forces over too large an area, thus introducing a blade deformation over too great a proportion of the length of the blade. This is usually done by providing that between each pair of adjacent heater elements there be an air space adequate to provide some degree of thermal isolation of the heated portions from one another. These may conveniently take the form of slots through a portion or all of the thickness of the die blade.
In one embodiment of the invention, (illustrated in FIG. 3), the temperature adjustment means is provided by a plurality of individual blocks provided with the necessary heating and if desired cooling means.
The blade is provided with elongated apertures at right angles to the block lip to receive the blocks and leave an insulating air gap around each. Thus when the block is bolted to the blade, only the top and bottom are rigidly restrained and the expansion and contraction of the block will produce substantially localized deformations of the adjacent portion of the die blade lip.
In some circumstances it is advantageous to provide that the blocks have larger coefficients of expansion than the material of the die blade so as to enhance the effect of relatively minor temperature variations. For this reason brass or aluminum blocks are often preferred.
In each die blade there is a neutral bending axis defining the line along which the metal is neither compressed nor stretched when the blade is flexed. Expansion forces acting mainly above this line will tend to produce deformations between points at which the blade is anchored. Forces acting mainly below the line are better capable of generating local deformations. It is therefore a preferred feature that the heaters be located at least predominantly below the neutral bending axis, that is to say predominantly between the axis and the die blade lip. Moreover location of a further set of heaters similar to the heaters used in the device of the invention but located above the neutral bending axis can be used to generate coarse adjustments of the blade gap of the type that might otherwise be handled by adjustment of jackbolts.
In all embodiments of the invention the portion of the die blade in contact with the resin is insulated from the temperature fluctuations in the temperature adjustment means by the provision of a heat barrier means disposed in the body of the blade between the temperature adjustment means and the die blade lip. This heat barrier means can be an insulation layer but in practice this would often tend to absorb the expansion forces designed to deform the blade. It is very much preferred therefore that the heat barrier means comprise a passage running the length of the die blade and adapted to circulate a heat transfer liquid at a constant temperature. This circulating liquid then absorbs the temperature variations generated by the temperature adjustment means and prevents them from affecting the melt temperature as it exits the die.
The die can comprise two such die blades but more commonly only one is required, the opposed surface defining the die orifice being fixed with respect to the adjustable blade.
To make most effective use of the great responsiveness of the die of the invention, it is desirable that the temperature adjustment means are connected up by computer relays to a gauge sensing means and are adapted immediately to produce an appropriate change in the temperature of the portion of the blade corresponding to the position at which a gauge variation has been identified.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a partial plan view of a die blade of the invention.
FIG. 2 shows a cross-section along the line 2--2 of the die blade illustrated in FIG. 1 in place of an extrusion slit die. The die is shown in diagrammatic cross-section.
FIG. 3 shows a partial longitudinal cross-section of an alternative die blade of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is now further described in relation to the attached drawings which are for the purpose of illustration only and are not intended to imply any limitation on the essential scope of the invention.
Referring to the embodiment described in FIGS. 1 and 2, the die blade, 1, comprises a chiselled lip portion, 2, that in use is the portion contacting the extruding polymer. The body of the blade is provided with a plurality of temperature adjustment means in the form of heater elements, 3. These heater elements are present in spaced alignment along the length of the blade. The die blade is provided with slots, 5, between each pair of heater elements to provide some degree of insulation. The die blade is secured to the die block, 9, by bolts, 6.
Between the row of heater elements and the lip of the die blade is a heat barrier means in the form of a passage, 4, running substantially the length of the blade and adapted to carry a heat transfer liquid and act as a heat sink to prevent any temperature fluctuation in the body of the blade from significantly affecting the temperature of the die blade lip.
The die blade of the invention is preferably provided with a layer of insulating material, 8, between it and the die block, 9, to which it is bolted. An alternative expedient is to hollow out a portion of the blade bolted to the die block such that the area in contact therewith is minimized.
In FIG. 3 which shows alternative embodiment of the invention the die blade, 11, has a die lip, 12, and, located in the slits, 14, in the body of the blade and oriented at right angles to the lip, a plurality of heater blocks, 13, of such dimensions that the block does not contact the sides of the slot. Each block bears against support studs, 17, affixed to an inelastic support, 15. The die blade is secured to the inelastic support by a plurality of bolts, 16. Each heater block is provided with heater elements, 18. A heat barrier between the die lip and the heater blocks is provided by the bore, 19, which is adapted to circulate a heat transfer fluid at a constant temperature.
In use and referring specifically to FIGS. 1 and 2, a thermoplastic resin is extruded through the channel, 7, and through the slit die provided by the lip, 2, of the die blade of the invention and an opposed stationary lip. The heater elements are heated to maintain the block at a constant temperature until a gauge variation is detected in the extruded sheet.
When this happens the current in the heater adjacent the point at which the gauge variation occurred is increased or reduced until the expansion or contraction forces so generated have adjusted the die gap in such a way as to eliminate the gauge variation.
The alternative embodiment illustrated in FIG. 3 functions in an essentially similar fashion.
The description provided above with reference to the drawings should not be taken as implying any limitation on the essential scope of the invention which is understood to embrace a plurality of minor variations and modifications that do not depart from the spirit of the invention.
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An improved slit die for extruding thermoplastic sheet and having the capacity for fine gauge control comprises a die blade and an opposed surface in which the local separation between the two is variable by the generation of localized expansion and contraction forces in the body of the die blade while isolating the die blade lip from temperature variations by the provision of a heat barrier means.
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FIELD OF THE INVENTION
[0001] This invention is the field of pharmaceutical compositions, specifically an enteric valproic acid gelatin capsule formulation.
[0002] This application claims priority under 35 U.S.C. 120 to U.S.S.N. 11/247,389 filed Oct. 11, 2005.
BACKGROUND OF THE INVENTION
[0003] Valproic Acid, or 2-propylpentanoic acid, and its salt and derivatives are used to treat absence seizures, complex partial seizures, mania, migraine headache prophylaxis, and behavior dyscontrol. Once in the body, valproic acid and its salts and derivatives are converted to valproate ion, which is responsible for the therapeutic effect. Valproic acid and its salt and derivatives are also known to cause significant side effects including gastrointestinal discomfort (nausea, indigestion, vomiting, diarrhea, and abdominal pain) which can decrease patient compliance.
[0004] Valproic acid and sodium valproate are difficult to formulate into solid oral dosage forms. Sodium valproate is extremely hygroscopic, often liquifying rapidly under ambient conditions. Valproic acid is an oily liquid at room temperature and thus not suitable for manufacturing solid dosage forms, e.g. tablets for oral administration.
[0005] Efforts have been made to address the problems associated with formulating valproic acid and sodium valproate into solid oral dosage forms. U.S. Pat. No. 5,017,613 to Aubert et al, describes a process for preparing a composition containing valproic acid in combination with valproate sodium. A mixture of valproic acid and ethylcellulose is prepared and valproate sodium is added to the mixture to form drug granules in the absence of any binder or granulating solvent. Precipitated silica is added to the granules before the granules are compressed into tablets. U.S. Pat. Nos. 5,212,326 and 4,988,731 to Meade describe divalproex sodium and its preparation. Divalproex sodium is a stable 1:1 ionic oligomer in which valproic acid forms coordinate bonds with the sodium of the sodium valproate salt.
[0006] Sustained release forms of divalproex sodium, valproic acid and its salts and derivatives have been developed in an effort to minimize the gastrointestinal side effects associated with these compounds. For example, U.S. Pat. No. 5,807,574 to Cheskin et al. describes a controlled release dosage form containing divalproex sodium and a process for its preparation. The process involves melting divalproex sodium and mixing it with a molten wax to form a divalproex sodium-wax composite. The drug-wax mixture is formulated into a capsule. U.S. Pat. No. 5,169,642 to Brinker et al. describes a sustained release dosage form containing granules of divalproex sodium, valproic acid or amides or esters or salts thereof and a polymeric viscosity agent. The drug is coated with a sustained release composition comprising specified portions of ethylcellulose or a methacrylic methylester, a plasticizer, and a detactifying agent.
[0007] Enteric-coated dosage forms are typically produced by a film coating process, where a thin film layer of an acid-insoluble (enteric) polymer is applied to the surface of a pre-manufactured dosage form, such as a tablet, and to a lesser extent hard and soft capsules. The enteric coating is sprayed as an aqueous or organic solution or suspension of one or more enteric polymers onto tumbling or moving tablets or capsules, followed by drying at elevated temperatures. Enteric dosage forms made by this coating method can suffer from various process-related problems that affect the performance and/or appearance of the coating. For example, “orange peel” surface formation, also known as surface roughness or mottling, may result. More seriously, coat integrity failure may occur, such as cracking or flaking off of the enteric polymer coating.
[0008] U.S. Pat. No. 5,068,110 to Fawzi et al. describes various currently marketed delayed-release tablets and capsules, including the delayed-release divalproex sodium tablets manufactured by Abbott Laboratories (Depakote® ER). Fawzu states that the stability of the enteric coated capsules is increased by applying thicker layer of the enteric coating, alone or in combination with hydroxypropyl cellulose or hydroxymethylcellulose.
[0009] All coating processes present inherent problems, including possible uneven distribution of the coating ingredients, which can occur under multivariate coated processes. These problems are common to all enteric dosage forms. However, the problems faced during the coating of gelatin or polysaccharide capsules are even more critical due to the delicate and heat sensitive nature of the soft elastic capsule shell. Both hard and soft capsules can undergo thermally induced agglomeration and distortion of the capsule shell. Moreover, the smoothness and elasticity of the capsule surface makes it difficult to form an intact adhering enteric coating. Moreover, the enteric coatings cause the loss of the normally shiny and clear appearance of gelatin capsule shells, which is a major reason for the popularity and acceptance of gelatin capsules. WO 2004/030658 to Banner Pharmacaps, Inc. describes a process and resulting enteric capsule which avoids these problems with most drugs by incorporating the enteric polymer into the gelatin, rather than onto the gelatin.
[0010] It is therefore an object of the present invention to provide an enteric valproic acid soft gelatin capsule dosage form which does not suffer from the processing limitations and poor stability associated with traditional enteric coated dosage forms.
[0011] It is another object of the present invention to provide an enteric valproic acid soft gelatin capsule dosage from which minimizes the gastrointestinal side effects associated with valproic acid.
[0012] It is yet another object of the present invention to provide an enteric valproic acid soft gelatin capsule dosage form which is smaller, uses fewer ingredients, and is therefore easier to swallow, than conventional enteric valproic acid dosage forms.
[0013] It is still another object of the present invention to provide a method of making an enteric valproic acid soft gelatin capsule dosage form which is more economical than other methods.
SUMMARY OF THE INVENTION
[0014] An enteric valproic acid soft gelatin capsule, in which the enteric polymer is a component of the capsule shell rather than a coating, has been developed. The fill material comprises valproic acid or divalproex sodium and, optionally, one or more pharmaceutically acceptable excipients such as corn oil. The capsule shell is prepared from a mass comprising a film-forming polymer, an acid insoluble polymer, an aqueous solvent, and optionally a plasticizer. Suitable film-forming polymers include gelatin. Suitable acid-insoluble polymers include acrylic-acid/methacrylic acid copolymers. The acid-insoluble polymer is present in an amount from about 8% to about 20% by weight of the wet gel mass. The weight ratio of acid-insoluble polymer to film-forming polymer is from about 25% to about 50%. The aqueous solvent is water or an aqueous solution of alkalis such as ammonia or diethylene amine or hydroalcoholic solutions of the same. Suitable plasticizers include glycerin and triethylcitrate.
[0015] The enteric soft gelatin capsule does not require an enteric coating and thus is not susceptible to the processing problems associated with enteric coated dosage forms. Enteric valproic acid soft gelatin capsules can be smaller in size and thus easier to swallow than currently available enteric coated tablets due to the presence of fewer ingredients, as well as smaller amounts of ingredients, in the capsule shell. In addition, the cost of manufacture due to the fewer processing steps and ingredients, is significantly less than with other methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a graph of the mean serum concentration of valproic acid from 0 to 72 hours after dose administration of Valproic Acid Enteric 500 mg Softgel Capsules under fasting and non-fasting conditions, and Depakote© Delayed-Release 500 mg Tablets under fasting conditions.
[0017] FIG. 2 is a graph of the mean serum concentration of valproic acid from 0 to 72 hours after dose administration of Valproic Acid Enteric 500 mg Softgel Capsules and Depakote© Delayed-Release 500 mg Tablets under non-fasting conditions.
[0018] FIG. 3 is a graph of the estimated time to steady state for Valproic Acid Enteric 500 mg Softgel Capsules and Depakote© Delayed-Release 500 mg Tablets based on pharmacokinetic data.
DETAILED DESCRIPTION OF THE INVENTION
[0000] I. Composition
[0019] A. Capsule Fill
[0020] 1. Valproic Acid
[0021] Valproic acid, or 2-propylpentanoic acid, and its salts and derivatives are compounds which have been used to treat absence seizures, complex partial seizures, mania, migraine headaches prophylaxis, and behavior dyscontrol. Valproic acid (available from Sifa Ltd., Shannon, Ireland; Interchem and Katwijk Chemie, the Netherlands; and Generichem) is an oily liquid at room temperature. Valproic acid is colorless and has a characteristic odor. It is slightly soluble in water (1.3 mg/mL) and very soluble in organic solvents. Valproic acid can be used neat or as a solution. The concentration of valproic acid in the fill material is from about 25% to about 100% by weight of the fill material. In the preferred embodiment, divalproex sodium is present in the fill at a concentration of about 40% by weight of the fill. Total dosage per capsule is typically 250 mg, although 125 mg and 500 mg sizes are also useful.
[0022] Divalproex sodium can also be used in the formulation of enteric soft gelatin capsules. Divalproex sodium is a 1:1 molar ratio oligomer of free valproic acid and sodium valproate. Divalproex sodium (available from SST Crop., New Jersey) is a white, crystalline powder, which is soluble in water and alcoholic solvents such as methanol and ethanol, as well as organic solvents such as cyclohexane.
[0023] 2. Excipients
[0024] The capsule fill may be prepared using a pharmaceutically acceptable carrier composed of materials that are considered safe and effective and may be administered to an individual without causing undesirable biological side effects or unwanted interactions. The carrier consists of all components present in the pharmaceutical formulation other than the active ingredient or ingredients. As generally used herein “carrier” includes, but is not limited to, plasticizers, crystallization inhibitors, wetting agents, bulk filling agents, solubilizers, bioavailability enhancers, solvents, pH-adjusting agents and combinations thereof.
[0025] Suitable excipients include one or more solubilizers such as soybean oil, rapeseed oil, safflower oil, corn oil, olive oil, castor oil, oleic acid, medium chain triglycerides, mono- and diglycerides (available from Abitec Corp., Columbus, Ohio, under the tradename Capmul®), medium chain triglyceride esters (available from Abitec Corp., Columbus, Ohio, under the tradename Captex®), medium chain partial triglycerides (available from Sasol under the tradename Imwitor®), corn oil-PEG 6 complex (available from Gattefosse S.A., Saint Priest, France under the tradename Labrasol®), propylene glycol monolaurate (lauraglycol), long chain partial glycerides (available from Gattefosse S.A., Saint Priest, France, under the tradename Maisine®), sorbitan monooleate (available from ICI under the tradename Span®), polysorbates (available from ICI under the tradename Tween®), ethoxylated castor oil (cremophors), bees wax, hydrogenated soybean oil, partially hydrogenated soybean oil, and acetylated triglycerides. In a preferred embodiment, the solubilizer is corn oil.
[0026] B. Capsule Shell
[0027] The capsule shell is prepared from a gelatin mass comprising a film-forming polymer, an acid-insoluble polymer which is present in an amount making the capsule resistant to the acid within the stomach, an aqueous solvent, and optionally, one or more plasticizers and/or colorants. Other suitable shell additives including opacifiers, colorants, humectants, preservatives, flavorings, and buffering salts and acids. Enteric capsule shells and a method of making the capsule shell are described in WO 2004/030658 to Banner Pharmacaps, Inc.
[0028] 1. Film-Forming Polymers
[0029] Exemplary film-forming polymers can be of natural or synthetic origin. Natural film-forming polymers include gelatin and gelatin-like polymers. Other suitable natural film-forming polymers include shellac, alginates, pectin, and zeins. Synthetic film-forming polymers include hydroxypropyl methyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose acetate phthalate, and acrylates such as poly(meth)acrylate. The weight ratio of acid-insoluble polymer to film-forming polymer is from about 15% to about 50%. In one embodiment, the film forming polymer is gelatin.
[0030] 2. Acid-Insoluble Polymers
[0031] Exemplary acid-insoluble polymers include cellulose acetate phthalate, cellulose acetate butyrate, hydroxypropyl methyl cellulose phthalate, algenic acid salts such as sodium or potassium alginate, shellac, pectin, acrylic acid-methylacrylic acid copolymers (available under the tradename EUDRAGIT® from Rohm America Inc., Piscataway, N.J. as a powder or a 30% aqueous dispersion; or under the tradename EASTACRYL®, from Eastman Chemical Co., Kingsport, Tenn., as a 30% dispersion). In one embodiment, the acid-insoluble polymer is EUDRAGIT® L100, which is a methacrylic acid/methacrylic acid methyl ester copolymer. The acid-insoluble polymer is present in an amount from about 8% to about 20% by weight of the wet gelatin mass. The weight ratio of acid-insoluble polymer to film-forming polymer is from about 15% to about 50%.
[0032] 3. Aqueous Solvent
[0033] Exemplary aqueous solvents include water or aqueous solutions of alkalis such as ammonia, sodium hydroxide, potassium hydroxide, ethylene diamine, hydroxylamine, tri-ethanol amine, or hydroalcoholic solutions of the same. The alkali can be adjusted such that the final pH of the gelatin mass is less than or equal to 9.0, preferably less than or equal to 8.5, more preferably less than or equal to 8.0. In one embodiment, the alkali is a volatile alkali such as ammonia or ethylene diamine.
[0034] 4. Plasticizers
[0035] Exemplary plasticizers include glycerol, glycerin, sorbitol, polyethylene glycol, citric acid, citric acid esters such as triethylcitrate, polyalcohols with 3-6 carbons and combinations thereof. The plasticizer to polymer (film forming polymer plus acid-insoluble polymer) ratio is from about 10% to about 50% of the polymer weight.
[0000] II. Method of Manufacture
[0036] A. Capsule Fill
[0037] Valproic acid or divalproex is dispensed into a suitable container and, optionally, mixed with a diluting vehicle such as corn oil. The fill is deaerated prior to encapsulation in a soft gelatin capsule.
[0038] B. Capsule Shell
[0039] A method of making the capsule shell is described in WO 2004/030658 to Banner Pharmacaps, Inc. The enteric gelatin mass can be manufactured by preparing an aqueous solution comprising a film-forming, water soluble polymer and an acid-insoluble polymer and mixing the solution with one or more appropriate plasticizers to form a gelatin mass. Alternatively, the enteric gelatin mass can be prepared by using a ready-made aqueous dispersion of the acid-insoluble polymer by adding alkaline materials such as ammonium, sodium, or potassium hydroxides or other alkalis that will cause the acid-insoluble polymer to dissolve. The plasticizer-wetted, film-forming polymer can then be mixed with the solution of the acid-insoluble polymer. The gelatin mass can also be prepared by dissolving the acid-insoluble polymer or polymers in the form of salts of the above-mentioned bases or alkalis directly in water and mixing the solution with the plasticizer-wetted, film-forming polymer. The gelatin mass is cast into films or ribbons using heat controlled drums or surfaces. The fill material is encapsulated in a soft gelatin capsule using a rotary die. The capsules are dried under controlled conditions of temperature and humidity. The final moisture content of the shell composition is from about 2% to about 10% by weight of the capsule shell, preferably from about 4% to about 8% by weight by weight of the capsule shell.
[0000] III. Method of Use
[0040] Enteric valproic acid soft gelatin capsules can be used to administer valproic acid or divalproex sodium to a patient in need thereof. In the preferred embodiment the capsule contains dose equivalents of 125 mg, 250 mg, or 500 mg.
[0041] The data in the following examples demonstrates that it is possible to make capsules or soft gelatin capsules that release valproic acid to produce the following pharmacokinetic profiles:
[0042] wherein the valproic acid is released following oral administration to a fasting individual to produce a C max between approximately 37.6 and 72.5 mg valproic acid/ml blood with a T max of between 1 and 4 hours, more preferably wherein the C max is between 42.3 and 67.5 mg valproic acid/ml blood with a T max of between 1.35 and 3 hours; and
[0043] wherein the valproic acid is released following oral administration to a non-fasting individual to produce a C max between 27.2 and 58.64 mg valproic acid/ml blood with a T max of between 3 and 9 hour, more preferably wherein the C max is between 31 and 53.8 mg valproic acid/ml blood with a T max of between 3 and 9 hours.
[0044] Although described in the examples with reference to specific enteric polymer containing soft gelatin capsules, those skilled in the art will recognize that other capsules or soft gelatin capsules can be similarly prepared to achieve equivalent pharmacokinetic drug profiles.
EXAMPLES
Example 1
Enteric Gelatin Mass
[0045] A gelatin mass was made according to the formula below.
Gelatin 28.00% Eudragit ® L100 9.00% Glycerin 15.4% Triethyl citrate 0.90% Ammonium hydroxide 0.05% Water 46.65%
[0046] The acid insoluble polymer (Eudragit® L 100) was dissolved in an aqueous alkali solution (water and ammonium hydroxide). The film-forming polymer (gelatin), and any plasticizers (glycerin), colorants, or other shell additives were added to the acid insoluble polymer solution and the mixture was cooked via a hot-melt process. The water content of the gelatin mass was adjusted to the indicated level. The gelatin mass was deaerated and dropped into a receiver. The dropped gelatin mass was held in the receivers at a temperature between 110 and 140° F. until encapsulation.
Example 2
Enteric Soft Capsules with Valproic Acid Fill
[0047] Enteric soft capsules were prepared using a conventional rotary die process. The enteric gelatin mass from Example 1 was cast as a thin ribbon. The appropriate fill mass was pumped into each die cavity in order to provide the appropriate fill weight. After the die cavities were filled, the ribbon was sealed to form capsules of the desired shape and size. The capsules were dried initially in a tumble dryer and then dried on trays in a drying tunnel until the desired hardness was achieved. The dried capsules were then inspected, sized, printed, polished and packaged.
Example 3
Relative Bioavailability Study of Valproic Acid Enteric 500 mg Softgel Capsules Under Fasting Conditions
[0048] The pharmacokinetic parameters of Valproic Acid Enteric 500 mg Softgel capsules was compared to that of a reference compound. Depakote® Delayed-Release Tablets (500 mg).
[0049] The objective of this randomized, single-dose, three-way crossover study was to compare, under fasting conditions, the relative bioavailability (rate and extent of absorption) of Valproic Acid Enteric 500 mg Softgel to that of an equivalent dose of Depakote® Delayed-Release Tablets, when administered to healthy subjects.
[0050] Material and Methods
[0051] Thirty-six healthy adults participated in the comparison between Valproic Acid Enteric 500 mg Softgel and Depakote® Delayed-Release Tablets. All 36 subjects completed the study. On Day 1, following an overnight fast of at least 10 hours, subjects received a single, oral dose (1×500 mg) of either the test Valproic Acid Enteric 500 mg Softgel or the reference Depakote® Delayed-Release Tablets 500 mg with 240 mL ambient temperature water, as per the randomization scheme.
[0052] During each study period, 21 blood samples were collected (7 mL each) from each subject by direct venipuncture using pre-labeled vacutainers without anticoagulant. Blood samples were collected within 1 hour prior to dose administration (0 hour) and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 12, 16, 24, 36, 48, and 72 hours after dose administration.
[0053] Approximately 441 mL of blood was collected from each subject for pharmacokinetic samples over the course of the study. Upon completion of the clinical study, the serum samples were transferred to the PRACS Institute, Ltd. Bioanalytical Laboratory for sample analysis.
[0054] Serum concentration data from all 36 subjects were used in the pharmacokinetic and statistical analysis. The lower limit of quantitation for valproic acid was 2.00 μg/mL. For statistical analysis, subject sample values below the lower limit of quantitation (BLQ) were reported as zero.
[0055] The following pharmacokinetic parameters were calculated for each subject and period: peak concentration in plasma (C max ), time to peak concentration (T max ), elimination rate constant (k e ), terminal half-life (t 1/2 ), area under the concentration-time curve calculated according to the linear trapezoidal rule (AUC 0-t ), and area under the plasma concentration time curve from time-zero extrapolated to infinity (AUC 0-∞).
[0056] An analysis of variance (ANOVA) was performed on each of the pharmacokinetic parameters using SAS® software. The ANOVA model containing factors for sequence of products, subjects within sequence, periods and products was utilized in comparing the effects between the test and reference products. Differences were declared statistically significant at the 5% level.
[0057] A 90% confidence interval about the ratio of the mean test value to mean reference value was calculated for all of the pharmacokinetic parameters for each test product. The calculations for the confidence intervals used the least squares means (LSMEANS) and the standard error of the estimate, both generated by the SAS® software. The ratio of the geometric means for the In-transformed data and the corresponding 90% confidence intervals were calculated for AUC 0-t , AUC 0-∞ , and C max , as well. The statistical analysis was done using SAS®, Version 8.2 for Windows, using code based on Chow and Liu pp. 559-562.
[0058] Results
[0059] Table 1 shows both the non-transformed and the In-transformed data for the calculated pharmacokinetic parameters for Depakote® Delayed-Release Tablets (Treatment A) and Valproic Acid Enteric Softgel capsules (Treatment C). Table 1 also shows the statistical analysis of the non-transformed and the In-transformed data.
[0060] The 90% confidence intervals about the ratio of Treatment A (Test Product Fasting) geometric mean to Treatment C (Reference Product Fasting) geometric mean are within the 80% and 125% limits for the pharmacokinetic parameters C max , AUC 0-t , and AUC 0-∞ of the In-transformed data.
[0061] FIG. 1 shows the mean serum concentration of valproic acid from 0 to 72 hours after dose administration for Treatment A (Test Product Fasting) and Treatment C (Reference Product Fasting).
[0062] The results of this study indicate bioequivalence between the test Valproic Acid Enteric 500 mg Softgel and the reference Depakote® Delayed-Release Tablets 500 mg when administered under fasting conditions.
TABLE 1 Ln- and Non-Transformed Pharmacokinetic Parameters of Valproic Acid After Oral Administration and Statistical Analysis Treatment A (Test Product Fasting) vs. Treatment C (Reference Product Fasting) N = 36 Ln-Transformed Data 90% Confidence Least Squares Mean Geometric Mean Interval PK Treatment Treatment Treatment Treatment Mean Square (Lower Limit, Variable A C A C % Ratio Error Upper Limit) C max 3.981 4.009 53.58 55.10 97.24 0.01210 (93.13, 101.54) AUC 0-t 6.787 6.824 886.52 919.81 96.38 0.00295 (94.35, 98.46) AUC 0-∞ 6.877 6.908 969.52 1000.45 96.91 0.00272 (94.94, 98.92) Non-Transformed Data 90% Confidence Least Squares Mean Interval Pk Treatment Treatment Mean Square (Lower Limit, Variable A C % Ratio Error Upper Limit) C max 53.98 55.61 97.06 25.63 (93.49, 100.64) AUC 0-t 905.97 936.03 96.79 2318.10 (94.77, 98.81) AUC 0-∞ 989.01 1018.00 97.15 2483.63 (95.23, 99.08) T max 2.32 3.69 62.80 2.9737 (44.44, 81.15) k e 0.0476 0.0473 100.58 0.00001 (97.93, 103.23) t 1/2 15.07 15.32 98.41 0.9780 (95.87, 100.94) Geometric means are based on least squares means of ln-transformed values.
Example 4
Relative Bioavailability Study of Valproic Acid Enteric 500 mg Softgel Capsules Under Fed Conditions
[0063] The objective of this randomized, single-dose, three-way crossover study was to compare the relative bioavailability (rate and extent of absorption) of Valproic Acid Enteric 500 mg Softgel under fasting and non-fasting conditions, when administered to healthy subjects. To determine the food effects for Valproic Acid Enteric Softgel, the pharmacokinetic data under fasting conditions was used as a reference. The same thirty-six subjects from Example 3 were enrolled in the food effect study.
[0064] Materials and Methods
[0065] All thirty-six enrolled subjects completed the study. For those subjects to be dosed under non-fasting conditions, a standardized, high fat breakfast was served 30 minutes prior to dose administration, as per the randomization. Thirty minutes after starting the standardized, high fat breakfast, subjects received a single, oral dose (1×500 mg) of the test Valproic Acid Enteric 500 mg Softgel with 240 mL of ambient temperature water. All subjects fasted for at least 4.25 hours after dosing. There was at least a seven day washout between study periods. Blood sample were taken and analyzed as described in Example 3.
[0066] Table 2 shows both the non-transformed and the In-transformed data for the calculated pharmacokinetic parameters for Valproic Acid Enteric Softgel capsules under fasting conditions (Treatment A) and Valproic Acid Enteric Softgel capsules under fed (non-fasting) conditions (Treatment B). Table 2 also shows the statistical analysis of the non-transformed and the In-transformed data.
[0067] The 90% confidence intervals about the ratio of Treatment A (Test Product Fasting) geometric mean to Treatment B (Test Product Non-Fasting) geometric mean are within the 80% and 125% limits for the pharmacokinetic parameters AUC 0-t , and AUC 0-∞ , but not for C max , of the In-transformed data.
TABLE 2 Ln- and Non-Transformed Pharmacokinetic Parameters of Valproic Acid After Oral Administration and Statistical Analysis Treatment B (Test Product Non-Fasting) vs. Treatment A (Test Product Fasting) N = 36 Ln-Transformed Data 90% Confidence Least Squares Mean Geometric Mean Interval PK Treatment Treatment Treatment Treatment Mean Square (Lower Limit, Variable B A B A % Ratio Error Upper Limit) C max 3.714 3.981 41.02 53.58 76.56 0.01210 (73.32, 79.94) AUC 0-t 6.745 6.787 849.44 886.52 95.82 0.00295 (93.79, 97.88) AUC 0-∞ 6.833 6.877 929.53 969.52 95.88 0.00272 (93.93, 97.86) Non-Transformed Data 90% Confidence Least Squares Mean Interval PK Treatment Treatment Mean Square (Lower Limit, Variable B A % Ratio Error Upper Limit) C max 41.70 53.98 77.25 25.63 (73.56, 80.93) AUC 0-t 869.15 905.97 95.94 2318.10 (93.85, 98.02) AUC 0-∞ 950.62 989.01 96.12 2483.63 (94.14, 98.1) T max 6.09 2.32 262.88 2.9737 (233.65, 292.1) k e 0.0479 0.0476 100.60 0.00001 (97.96, 103.24) t 1/2 13.04 15.07 99.77 0.9780 (97.19, 102.35) Geometric means are based on least squares means of ln-transformed values.
[0068] FIG. 1 shows the mean serum concentration of valproic acid from 0 to 72 hours after dose administration for Treatment A (Test Product Fasting) and Treatment B (Test Product Non-Fasting).
[0069] The administration of Valproic Acid 500 mg Enteric Softgel capsules with food significantly decreased the In-transformed C max (23.44%). However, food did not significantly decrease the In-transformed ACU 0-t (4.18%) and In-transformed AUC 0-∞ (4.12%). Thus, administration of Valproic Acid Enteric 500 mg Softgel under non-fasting conditions did not affect the extent of absorption.
Example 5
Relative Bioavailability Study of Valproic Acid Enteric 500 mg Softgel Capsules Under Non-Fasting Conditions
[0070] An interview by Banner Pharmacaps, Inc. of physicians (N=24) indicated that a majority of their patients take Depakote© with food. Therefore, a randomized, two-way crossover design was used to compare the relative bioavailability (rate and extent of absorption) of Valproic Acid 500 mg Capsules with the reference compound, Dekapote© 500 mg Delayed-Release Tablets, under non-fasting conditions.
[0071] Materials And Methods
[0072] Six healthy subjects were used in this study. A single oral dose was administered to subjects on two separate occasions under non-fasting conditions with a 7 day washout between doses. Food and fluid intake were controlled during each confinement period.
[0073] Serum concentrations of valproic acid were determined by the bioanalytical laboratory of PRACS Institute, Ltd. Data from all six subjects was used for pharmacokinetic and statistical analysis. The pharmacokinetic parameters that were calculated were the same as for Examples 3 and 4. Actual times were used in the calculation of pharmacokinetic parameters.
[0074] Results
[0075] Table 3 shows the In-transformed data for the calculated pharmacokinetic parameters, C max , AUC 0-t , and AUC 0-∞ , for Valproic Acid Enteric Softgel Capsules (Test Product) and Depakote© Delayed-Release Tablets (Reference Product). Table 3 also shows the statistical analysis of the In-transformed data.
TABLE 3 Ln-Transformed Pharmacokinetic Parameters of Valproic Acid After Oral Administration and Statistical Analysis Ln- Ln- Ln- Transformed Transformed Transformed Valproic Acid C max AUC 0-t AUC 0-∞ Test Product 42.40 804.19 879.12 Geometric Mean Reference Product 50.49 856.91 922.54 Geometric Mean % Ratio 83.97 93.85 95.29 90% Confidence (74.45, 94.72) (88.78, 99.21) (92.03, 98.67) Intervals
[0076] Table 4 shows the non-transformed data for the calculated pharmacokinetic parameters, C max , AUC 0-t , and AUC 0-∞ , for Valproic Acid Enteric Softgel Capsules (Test Product) and Depakote© Delayed-Release Tablets (Reference Product). Table 4 also shows the statistical analysis of the non-transformed data.
TABLE 4 Non-Transformed Pharmacokinetic Parameters of Valproic Acid After Oral Administration and Statistical Analysis Valproic Acid C max AUC 0-t AUC 0-∞ Test Product 42.96 815.73 887.98 Geometric Mean Reference Product 51.26 869.81 932.21 Geometric Mean % Ratio 83.81 93.78 95.26 90% Confidence (74.34, 93.28) (88.18, 99.39) (91.56, 98.95) Intervals
[0077] Table 5 shows the non-transformed data for the calculated pharmacokinetic parameters, T max , k e , and t 1/2 , for Valproic Acid Enteric Softgel Capsules (Test Product) and Depakote© Delayed-Release Tablets (Reference Product). Table 5 also shows the statistical analysis of the non-transformed data.
TABLE 5 Non-Transformed Pharmacokinetic Parameters of Valproic Acid After Oral Administration and Statistical Analysis Valproic Acid T max k e t 1/2 Test Product 5.00 0.0464 15.11 Least Squares Mean Reference Product 10.67 869.81 932.21 Least Squares Mean % Ratio 46.88 93.78 95.26 90% Confidence (24.28, 69.47) (87.56, 100.81) (99.44, 113.48) intervals
[0078] FIG. 2 shows the mean serum concentrations of valproic acid among subjects at each time point tested from 0 to 72 hours after dose administration of Valproic Acid Enteric Softgel Capsules (Enteric Valproic Acid 500 mg) and Depakote© Delayed-Release Tablets (Depakote 500 mg).
[0079] The results of this study indicate near equivalence of Valproic Acid Enteric Softgel Capsules and Depakote© Delayed-Release Tablets under non-fasting conditions with respect to the pharmacokinetic parameters C max , AUC 0-t , and AUC 0-∞ . However, Valproic Acid Enteric Softgel Capsules induced a significantly lower T max , relative to Depakote© Delayed-Release Tablets, indicating a faster onset of action under non-fasting conditions.
Example 6
Relative Estimated Time to Steady State of Valproic Acid 500 mg Capsules
[0080] Time to steady state for Valproic Acid 500 mg Capsules and Depakote© Delayed-Release Tablets was estimated based on pharmacokinetic data from Example 5, as shown in FIG. 3 . This estimation predicts that Valproic Acid 500 mg Capsules may attain steady state in 52 hours, while Depakote© Delayed-Release Tablets may attain steady state in 72 hours. Thus, Valproic Acid 500 mg Capsules are predicted to reach steady state 25% faster than Depakote© Delayed-Release Tablets.
[0081] It is understood that the disclosed invention is not limited to the particular methodology, protocols, and reagents described as these may vary. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed invention belongs.
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An enteric valproic acid soft gelatin capsule, in which the enteric polymer is a component of the capsule shell rather than a coating, has been developed. The fill material comprises valproic acid or divalproex sodium and, optionally, one or more pharmaceutically acceptable excipients such as corn oil. The capsule shell is prepared from a mass comprising a film-forming polymer, an acid insoluble polymer, an aqueous solvent, and optionally a plasticizer. Suitable film-forming polymers include gelatin. Suitable acid-insoluble polymers include acrylic-acid/methacrylic acid copolymers. The acid-insoluble polymer is present in an amount from about 8 % to about 20 % by weight of the wet gel mass. The weight ratio of acid-insoluble polymer to film-forming polymer is from about 25 % to about 50 %. The aqueous solvent is water or an aqueous solution of alkalis such as ammonia or diethylene amine or hydroalcoholic solutions of the same. Suitable plasticizers include glycerin and triethylcitrate. The enteric soft gelatin capsule does not require an enteric coating and thus is not susceptible to the processing problems associated with enteric coated dosage forms. Enteric valproic acid soft gelatin capsules may be smaller in size and thus easier to swallow than currently available enteric coated tablets due to the presence of fewer ingredients, as well as smaller amounts of ingredients in the capsule shell.
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FIELD OF THE INVENTION
[0001] The present invention relates to the generation, parsing, modification, structure and structuring of electronically stored digitized text. More particularly, the present invention relates to digitized textual documents and methods and devices for organizing, rendering and experiencing segments within a digitized text, of either a newly generated or a previously authored document, e.g., an ebook, along two or more distinguishable threads of organization of the segments or subsets of segments of the text.
BACKGROUND OF THE INVENTION
[0002] The market for and supply channels of digitized copies of textual documents, or “ebooks”, is presently well established in both domestic and international channels of commerce. Yet the prior art merely offers essential access to each ebook by presenting a single narrative line in simulation of the typical method of reading a hard copy text from front page to last page. While prior art ebook readers do allow a reader to (a.) record electronic bookmarks within an ebook, (b.) peruse an ebook on the basis of page number or key word selection, (c.) jump from page to page, and (d.) activate hyperlinks to move from one point to another point within an ebook, the prior art wholly fails to optimize the possibilities of offering two or more alternate narrative threads through a same ebook.
[0003] There is therefore a long felt need to provide a method and device to establish two or more threads of separately associated segments which a reader may selectively follow while accessing an ebook.
SUMMARY OF THE INVENTION
[0004] Toward this and other objects that are made obvious in light of the disclosure, a method and system are provided for separating a digitized textual document into a plurality of textual segments, wherein each textual segment (hereinafter, “segments”) may be associated with one or more unique tags. One or more pluralities of segments may be associated with unique tags, wherein a first plurality of segments may be defined by associating each segment of the first plurality of segments with a first tag, and additional pluralities of segments are each defined by associating each segment of the particular plurality of segments with a unique and distinguishable tag. For example, a subset of segments of a source document may be selected out and each associated with a particular character. This exemplary subset of segments may, in an exemplary but not limited method, be associated with a common tag that represents an association with this particular character.
[0005] Additionally and optionally the segments may be further assigned sequence numbers that order each segment along a one-dimensional order wherein no two sequence numbers are equal, i.e., in a comparison of any two sequence numbers one sequence number will indicate an earlier relative position of the associated segment within the sequence of segments and the other sequence number of the other segment will indicate a later relative position within the sequence of segments.
[0006] Segments may be associated with tags that includes various literary qualities and aspects, such as, but not limited to, one or more characters, narrators, points of view, scenes, moments in time, locales, themes, object, and/or other suitable literary aspects or qualities.
[0007] It is understood that the digitized textual document may be a digitized representation of a previously written text, e.g., “Ulysses” by James Joyce, or may be a newly authored work that is separated into segments and organized with two or more distinguishable pluralities of uniquely and differently tagged segments.
[0008] Two or more segments may include references to scenes and time line moments, wherein two or more segments may be associated with a same scene at a same time line moments, but might also each be disparately associated with different aspects of the source text, such as point of view, character or theme. Alternately or additionally, two or more segments may be associated with two or more different aspects of the source text.
[0009] When the segments are stored as segments records and tags are associated with at least two or more segments records, one or more software nodes may be instantiated at run time and/or stored within node records in electronic memory. Nodes are data structures that are associated with at least one segment record and are applied to, among other uses, to determine when two segments are associated with a same tag. For example, when two segments are each separately associated with a different character but are also tagged as being related to a same scene in a plot timeline, a node may be generated that comprises references to the scene, to both characters, and to the two segments.
[0010] According to a second aspect of the method of the present invention (hereinafter, the “invented method”), an editing system comprising an editor software is provided that enables a human editor to define and populate segment records and separate a textual document into segments having different tags or different combinations of tags.
[0011] According to a third aspect of the invented method, an ebook rendering device (hereinafter, the “ebook device”) comprising a reader software is provided that enables a human reader to select a thread of segments wherein each segment of a selected thread is associated with a same tag. The ebook device may be directed by the human reader to (a.) sequentially render each segment of a selected thread; (b.) selectively render two or more segments associated with a same node; (c.) select which tag from a plurality of tags to follow in order to sequentially render segments in accordance with a predefined thread of segments; and/or (d.) enable a human reader to select or input an aspect of the textual document to apply to the pluralities of segments and select a plurality of segments on the criterion of association with the selected or input aspect of the digitized document. The selected or input aspect of the digitized document might be a character, a setting, a reference to a point within a timeline, a theme, a locale, a dialogue, and/or or a literary quality.
[0012] According to a fourth aspect of the invented method, one or more segments might be associated with more than one tag, and some or all of the text of a segment might also be comprised within an additional segment or segment record.
[0013] According to a fifth aspect of the invented method, a software structure is established wherein a plurality of nodes are interrelated and each segment is associated with at least one node. The nodes may be generated in a compilation or execution performed in light of the associations of the segments and may optionally or alternately generated at a runtime of a software program.
[0014] Optionally or additionally one or more nodes may be linked to or associated with two or more associated segments. For example, a node may enable a fictional same scene in a novel to be explicated from both (a.) a first point of view of a narrator, and (b.) a second point of view of a character who is portrayed as being present within the same scene. The invented ebook reader device may optionally enable the human reader to access two or more segments that are with a same node wherein these segments may be further associated with different tags, e.g., character tags. For example, the human reader may enjoy perusing the different points of view of different characters related to a same scene and within the general plot line or narrative of the source digitized textual document.
[0015] According to a fifth optional aspect of the invented method, a non-transitory computer-readable medium is provided that enables the ebook device to render segments in accordance with one or more aspects of the invented method.
BRIEF DESCRIPTION OF THE FIGURES
[0016] FIG. 1 is a process chart of a first invented method of generating an outline of a multi-tagged ebook;
[0017] FIG. 2 is a process chart of a first invented method of preparing a multi-tagged ebook for publication;
[0018] FIG. 3 is a is a process chart of a first preferred embodiment of a user experience in reading the invented ebook of FIG. 2 ;
[0019] FIG. 4 is a representation of a digitized text of FIG. 1 divided into segments;
[0020] FIG. 5 is a schematic diagram of an exemplary first segment record in which a first segment of FIG. 3 of the invented ebook is comprised;
[0021] FIG. 6 is a schematic of node diagram that is organized in accordance with the invented ebook of FIGS. 1 , 2 and 3 and a plurality of segment records of FIG. 4 ;
[0022] FIG. 7 is a schematic diagram of an exemplary first segment record by which a first node FIG. 5 of the invented ebook is defined;
[0023] FIG. 8A is a block diagram of a first alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0024] FIG. 8B is a block diagram of a second alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0025] FIG. 8C is a block diagram of a third alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0026] FIG. 8D is a block diagram of a fourth alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0027] FIG. 8E is a block diagram of a fifth alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0028] FIG. 8F is a block diagram of a sixth alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0029] FIG. 8G is a block diagram of a seventh alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0030] FIG. 8H is a block diagram of an eighth alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0031] FIG. 8I is a block diagram of a ninth alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0032] FIG. 8J is a block diagram of a tenth alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0033] FIG. 8K is a block diagram of an eleventh alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0034] FIG. 8L is a block diagram of a twelfth alternate embodiment of a segment record of FIG. 4 and FIG. 5 ;
[0035] FIG. 9 is an exemplary node diagram, wherein each nodes references at least one segment record of FIG. 8 ;
[0036] FIG. 10 is a flow chart of an ebook reader in providing a user-interactive process that enables a human reader to access the invented ebook of FIG. 2 ;
[0037] FIG. 11 is a flowchart an invented method of applying a default tag for execution by the ebook reader in interaction with the reader;
[0038] FIG. 12 is a flowchart of an invented method of applying a user selected tag as executable by the ebook reader in interaction with the reader;
[0039] FIG. 13 is a flowchart of a additional aspects of the invented method of applying a user selected tag for execution by the ebook reader in interaction with the reader;
[0040] FIG. 14 is a flowchart of a fourth aspect of the invented method of applying a user selected tag as executable by the ebook reader in interaction with the reader;
[0041] FIG. 15 is an illustration of an ebook reader user interface;
[0042] FIG. 16 is an illustration of a second ebook reader interface;
[0043] FIG. 17 is a representation of a software table that associates tags of FIG. 5 with labels of FIG. 15 and FIG. 16 in one-to-one relationships;
[0044] FIG. 18 is a software flowchart of additional optional aspects of the system software of the ebook reader of FIG. 3 and FIG. 20 ;
[0045] FIG. 19 is a schematic diagram of an ebook editing system of FIG. 1 and publishing system of FIG. 2 ; and
[0046] FIG. 20 is a schematic diagram of an ebook reader.
DESCRIPTION
[0047] It is to be understood that this invention is not limited to particular aspects of the present invention described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.
[0048] Methods recited herein may be carried out in any order of the recited events which is logically possible, as well as the recited order of events.
[0049] Where a range of values is provided herein, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits ranges excluding either or both of those included limits are also included in the invention.
[0050] Unless defined otherwise, all technical and scientific terms used herein have the same meaning 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 also be used in the practice or testing of the present invention, the methods and materials are now described.
[0051] It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation.
[0052] Referring now generally to the Figures and particularly to FIG. 1 , FIG. 1 is a process chart of a first invented method of generating a multi-tagged ebook 2 that may be rendered by an invented ebook 4 . In step 1002 either an existing text is digitized or digitized text is generated and selected as a digitized source text 100 (hereinafter, “source text” 100 ). The source text 100 of step 1002 is then input into an editing system 200 by direct keyboard input, or by download from an electronics communications network, e.g., the Internet, or by upload from a computer medium, e.g., a digital memory stick or a digital memory disc. A human editor (hereinafter, “editor”) applies the editing system 200 in step 1006 to generate a plurality of digitized textual segments SG.001-SG.N (hereinafter, “segments” SG.001-SG.N) selected from the source text 100 . It is understood that elements of the source text 100 may be duplicated in more than one derivative segment SG.001-SG.N. In response to interaction with the editor, the editing system 200 forms separate segment records SR.001-SR.N in step 1008 , wherein each segment record SR.001-SR.N preferably contains at least one segment SG.001-SG.N. The editor assigns one or more tags T.01-T.N & T.DEF to one or more segment records SR.001-SR.N in step 1010 . The editor preferably, but optionally, alternatively or additionally, assign a unique sequence number SEQ.001 to SEQ.N to each segment record SR.001-SR.N, whereby each segment record SR.001-SR.N has a unique segment number SEQ.001-SEQ.N that orders the segments according to a one-dimensional sequence wherein no two segment records SR.001-SR.N have the same sequence number SEQ.001-SEQ.N and each SEQ,001-SEQ.N relates a specific and unique position within the one-dimensional hierarchical structure of the one-dimensional sequence.
[0053] The significance and utility of the invented method of the tags T.01-T.N and the segment records SR.001-SR.N will be further explicated in the present disclosure. Examples of aspects of the source text 100 that may be indicated by tags are scene, moment within a time line, character point of view, narrative thread, theme, alternate plot line, alternate time line and/or other suitable literary quality known in the art.
[0054] It is understood that the steps of 1006 through 110 may be accomplished as repeated loops, or as iterative loops, as may also be the case of steps 1002 through 1012 .
[0055] A pre-publication, formatted ebook outline 500 is thereupon generated in step 1012 , wherein the ebook outline 500 includes all of the segments SG.001-SG.N and segment records SR.001-SR.N generated in one or more execution of the steps of 1002 through 1012 , wherein one or more segment records SR.001-SR.N may be revised or deleted in this prepublication process. It is understood that the steps of 1006 through 110 may be accomplished as repeated loops, or as iterative loops, as may also be the case of steps 1002 through 1012 . It is further understood that graphics and additional digitized textual data may be linked with or added to the ebook outline 500 or one or more segment records SR.001-SR.N in one or more executions of step 1008 .
[0056] Referring now to FIG. 2 , FIG. 2 is a process chart of a publication is process. The ebook outline 500 is received by a publishing system 600 in step 2002 . A font range is assigned to the ebook outline 500 in step 2004 and a table of contents is formed and added to the ebook outline 500 in step 2006 . Preferably, a human publisher (hereinafter, “publisher”) selects and links skin art to the ebook outline 500 in step 2008 and frontispiece statements, e.g., copyright, publisher identification and address, ISBN and publication data, is added to the ebook outline 500 in step 2010 . Customized and/or standardized buttons, icons and signage are added to the ebook outline 500 in step 2012 . The publisher than permanently selects, signifies and assigns integral elements of the ebook outline 500 in step 2014 . The invented ebook 2 is then released in step 2016 for commercial or public distribution in step 2016 through electronic media and/or electronic communications networks, e.g., the Internet.
[0057] Referring now to FIG. 3 , FIG. 3 is a process chart of a human reader's access of the invented ebook 2 by means of an ebook reader 4 having a touch display screen 5 . It is understood that the ebook reader 4 may be a general purpose computer, e.g., a tablet, laptop or desktop computer, that is configured with an invented ebook reader software SW.1, or a special purpose ebook reader, such as a KINDLE™ or Nook™ ebook reader. The human reader (hereinafter, “reader”) downloads or uploads the ebook 2 into a digital memory 4 A of the ebook reader 4 in step 3002 and directs the ebook reader in step 3004 to initiate visual and/or auditory rendering of the invented ebook. It is further understood that the nodes ND.001-N.D of the ebook 2 might be recorded as node records 700 and stored in the ebook reader 4 and/or alternatively or optionally generated at run time by the ebook reader 4 and after receipt by the ebook reader 4 of a user selection command of the ebook 2 of step 3004 .
[0058] In optional step 3006 , the reader directs the ebook reader 4 to follow a tag T.01-T.N as selected by the reader in order to provide a user directed nodal pathway through the invented ebook 2 . In the alternative, the ebook reader 4 will follow a default nodal pathway through the invented ebook 4 when the reader makes no tag T.01-T.N selections by selecting segments records SR.001-SR.N is that each include a default tag T.DEF in an order determined by the sequence numbers SEQ.001-SEQ.N and sequentially rendering the segments SG.001-SG.N of these segment records SR.001-SR.N that include the default tag T.DEF.
[0059] In the reading process loop of step 3010 through step 3018 , the reader may direct the ebook reader 4 to proceed from step 3010 to step 3012 to exit the reading process loop 3010 through 3018 and proceed on to alternate computational operations. Alternatively, the reader may instruct the ebook reader 4 to proceed to iteratively render successive segment records SR.001-SR.N as accessed in accordance with a tag selection, or default tag selection, of step 3006 . In the alternative, the reader in step 3014 may select an alternate tag T.01-T.N. or an alternate segment record SR.001-SR.N associated with a current node ND.001-ND.N may be selected by the reader in step 3016 , or an alternate tag T.01-T.N or alternate node ND.001-ND.N may be selected by the reader in a search process of step 3018 .
[0060] Referring now to FIG. 4 , the source text 100 is illustrated as including a header 102 and being divided into segment SG.104 through Nth segment SG.N, wherein N may be as large as the total count of distinguishable words or characters of the source text 100 . It is noted that content of the source text 100 may be shared by, or duplicated within, one or more segments SG.104 through SG.N, as illustrated by shared content 114 .
[0061] Referring now to FIG. 5 , FIG. 5 is an illustration of an exemplary first segment record 302 that includes a first segment record header SRH.001, the first segment SG.104 of the source text 100 , and a first segment record tail SRT.001. The first segment record header SRH.001 includes a first segment record identifier SR.ID.001, the default tag T.DEF, and one or more tags T.01-T.N associated by the editor with the first segment SG.104, and a sequence number SEQ.001 assigned by the editor. The exemplary first record 302 may optionally further include references to one or more nodes ND.001-ND.N that are associated with the first segment record 302 . The optional first segment record tail SRT.001. contains data useful in managing and transmitting the first segment record SRT.001.
[0062] Referring now to FIG. 6 , FIG. 6 is an entity diagram of four nodes ND.001-ND.004 of the plurality of nodes ND.001-ND.N. The plurality of nodes ND.001-ND.N are instantiated and generated upon the basis of a query generated by a user in step 3006 , or alternatively by a default selection of the ebook reader software SW.1 when the reader does not select a tag T.01-T.N in step 3306 or later.
[0063] Referring now to FIG. 7 , FIG. 7 is an illustration of an exemplary first node record 702 by which the first node ND.001 of FIG. 5 of the invented ebook is defined and that includes a first node record header NRH.001 and a first node record tail NRT.001. The first node record header NRH.001 includes a first node record identifier NR.ID.001, one or more segment record identifiers SR.ID, one or more tags T.01-T.N by the instant reader query of step 3006 , and one or more node record identifiers NR.ID. The one or more tags T.01-T.N may alternatively provided as a default set of tags T.01-T.N by the ebook reader software SW.1.
[0064] Referring now generally to the Figures and particularly to FIGS. 8A through 8L , FIGS. 8A through 8L each present aspects of individual segment records SEG.800-SEG.822 that each contain unique (a.) sequence numbers SEQ.SEQ-822; (b.) segments of the source text SG.800-SG.822; and (c.) combinations of tags, a single sequence number, and a segments. A plurality of three segment records SR.800, SR.802, SR.804 and SR.806 each include a same plot line moment tag T.02 that indicates that each of the four segments SEG.800, SEG.802, SEG.804 and SEG.806 separately comprised within these four segment records SR.800, SR.802, 804 & SR.806 are tagged by the editor as occurring contemporaneously within a plot timeline. Segment records SR.800, SR.802, SR.804 and SR.806 thereby form, or are comprised within, a first plot line moment thread TH.02 as indicated in FIG. 9 .
[0065] The four segment records SR.802, SR.808, SR.810 & SR.812 each comprise a first character tag T.04 that indicates that the four individual segments SEG.802, SEG.808, SEG.810 & SEG.812 separately comprised within each of these four segment records SR.802, SR.808, SR.810 & SR.812 are each associated with a same first character. These four segment records SR.802, SR.808, SR.810 & SR.812 thereby define, or may be comprised within, a first character thread TH.2 as indicated in FIG. 9 .
[0066] Similarly, three narrative voice segment records SR.806, SR.814 & SR.816 each comprise a first narrative voice tag T.06 that indicates that each of the three individual segments SEG.806, SEG.814 & SEG.816 separately comprised within these three segment records SR.806, SR.814 & SR.816 are each associated with a same first narrative voice. The three narrative voice segment records SR.806, SR.814 & SR.816 thereby define, or may be comprised within, a first narrative voice thread TH.3 as indicated in FIG. 9 .
[0067] Referring now to FIG. 9 , FIG. 9 is a representation of a plurality of nodes ND.900-914 that are generated by the ebook reader 4 prior to, or at runtime, of the ebook 2 and that reference the segment records SEG.800-SEG.816 of FIG. 8 . Nodes ND.900, ND.902 and N 904 each reference at least one segment record SR.800, SR.802, SR.804 and SR.806 of the first plot line moment thread TH.02, wherein each of these four segment records SR.800, SR.802, SR.804 and SR.806 separately each include the plot line moment tag T.02. It is noted that the second node ND.902 references the two segment records SR.802 and SR.806.
[0068] Four nodes ND.902, ND.906, ND.908 and ND.910 each reference an individual segment record SR.802, SR.808, SR.810 and SR.812 that are comprised within the first character thread TH.04 and indicated by an inclusion of the first character tag T.04 in each of the first character thread segment records SR.802, SR.808, SR.810 & SR.812.
[0069] Three nodes ND.902, ND.912, and ND.914 each reference an individual segment record SR.806, SR.806, SR.814 and SR.816 that are comprised within the first narrative voice thread TH.06 and indicated by an inclusion of the first narrative voice tag T.06 in each of the first character thread segment records SR.806, SR.812 & SR.816.
[0070] It is understood that in various preferred embodiments of the method of the present invention that one or more nodes ND.001-ND.N may include more than a reference to a segment records SR.001-SR.N, and may comprise some or all of the structure and information of one or more segment records SR.001-SR.N.
[0071] FIG. 10 is a flow chart of the ebook reader 4 in providing a user-interactive process that enables the reader to access the invented ebook 2 in selectable pathways of nodes through the ebook 2 . The plurality of nodes ND.001-ND.N are generated by reader interaction in step 3006 of FIG. 3 , which may include the reader inputting or selecting an aspect of the ebook 2 that is associated with a tag T.001-T.N, or alternatively, by a default selection by the ebook reader software SW.1 of a default tag T.DEF. For example, where the editor wishes to associate a particular and unique third character tag T.BILL with a fictional character BILL mentioned in the invented ebook, the third character tag T.BILL will be entered by the editing system 200 as directed by the editor into selected segment records SG.001-SG.N. When the reader requests to sequentially access each segment record SG.001-SG.N that is associated with the third character tag T.BILL, the reader will input into the ebook reader 4 , by icon selection or textual input, an interest in the character BILL, and the reader software will thereupon generate and associate a node ND.001-ND.N for each segment record SG.001-SG.N that contains the third character tag T.BILL.
[0072] The ebook reader 4 may further optionally associate additional segment records SG.001-SG.N with one or more nodes ND.001-ND.N when an additional record SG.001-SG.N lacks a reference to the third character tag T.BILL but includes a degree of commonality with the immediately associated segment record SG.001-SG.N. For example, when the segment record SR.818 includes both (a.) a second plot line moment tag T.T2 and (b.) a place tag T.GARDEN that relates to a notional garden setting, and the segment record 820 includes both the second plot line tag T.T2 and the place tag T.GAR but also includes a reference to a fourth character tag T.SUE that relates to a fourth character SUE, the second node ND.002 may be generated by the editing software include a reference to the segment record SR.820 based on the commonality of the is sharing the place tag T.GARDEN and the second plot line moment tag T.T2. The ebook reader software SW.1 will thereby be enabled to expeditiously respond to requests by the reader to access segments SG.001-SG.N that are tangentially related to the previously selected third character T.BILL but do not include the third character T.BILL that is optionally the rationale for the a generation of the plurality of nodes ND.001-ND.N.
[0073] Referring now generally to the Figures and particularly to FIG. 10 , the ebook reader 4 is energized and boots up in step 1000 , and in step 10002 determines whether to cease processing the ebook reader software SW.1 and proceed on to alternate computational operations of step 10004 . When the ebook reader 4 determines to not proceed on to step 10004 from step 10002 , the ebook reader 4 proceeds on to step 10006 and to determine if an ebook 2 selection command has been received from the user. When a selection command is detected by the ebook reader 4 in step 10006 , the ebook reader 4 proceeds on from step 10006 to a first execution of step 10008 and to select a default first segment record SR.001 in step 10010 from which to render the default segment SG.104 unless the user inputs a segment select command that indicates selection of an identified alternate segment SG.106-SG.N or segment record SR.001-SR.N. The ebook reader 4 thereupon determines in step 10012 whether to follow a default tag T.DEF of step 10014 or a to follow a tag T.001-T.N provided or selected by the user in a tag selection command. The ebook reader then either generates the plurality of nodes N.001-ND.N that each reference or include at least one segment record SR.001-SR., and proceeds to render a segment SEG.104-SG.N in step 10018 selected from the first node ND.001-ND.N, by reference or inclusion in the instant node ND.001-ND.N. The ebook reader 4 then determines in step 10020 whether to continue sequentially rendering segments SG.001-SG.N by successive executions of the loop of steps 10008 through 10020 , or to proceed repeat an execution of step 10002 . The ebook reader software SW.1 provides the machine executable instructions required by the ebook reader 4 , as directed by user commands, to execute steps 10002 through 10020 .
[0074] Referring now generally to the Figures and particularly to FIG. 11 , FIG. 11 is a flowchart of a second preferred embodiment of aspects of the invented method of applying a default tag T.DEF for execution by the ebook reader 4 in interaction with the reader. The ebook reader 4 determines whether the reader has selected an ebook 2 for rendering in step 1102 , and moves on to alternate computational operations of step 1104 when the ebook reader 4 does not detect a user command to select an ebook 2 in step 1102 . When the ebook reader 4 in step 1102 detects a user command to select and render an ebook 2 , the ebook reader 4 proceeds on to step 1106 and initializes a segment counter CS, and determines in step 1108 whether a tag T.001-T.N has been selected or input by the user. When the ebook reader 4 determines in step 1108 that the user has input or selected a tag T.001-T.N, the ebook reader 4 proceeds form step 1108 to step 1110 and to perform the process of FIG. 12 .
[0075] Alternatively, when the ebook reader 4 determines in step 1108 that the user has not input or selected a tag T.001-T.N, the ebook reader 4 proceeds from step 1108 to step 1112 and to proceed to sequentially render the segment records SR.001-SR.N that reference the default tag T.DEF. The ebook reader 4 proceeds from step 1112 to execute the logic of steps 1112 through 1122 until the ebook reader 4 determines in an execution of step 1116 that the segment counter CS has been incremented by successive increments to become equal to a maximum count N of segment records SR.001-SR.N, or the user directs the ebook reader 4 to cease rendering the selected ebook 2 . More particularly, the ebook reader 4 sequentially examines each segment record SR.001-SR.N to determine if each segment record SR.001-SR.N references or includes the default tag T.DEF, and sequentially renders each segment record SR.001-SR.N that references or includes the default tag T.DEF in step 1120 . The user prompts the ebook reader 4 to proceed on to a next segment record in step 1122 .
[0076] Referring now generally to the Figures and particularly to FIG. 12 , FIG. 12 is a flowchart of a third preferred embodiment of aspects of the invented method applying a user selected tag T.001-T.N as executable by the ebook reader 4 in interaction with the reader. In steps 1200 through 1214 the ebook reader 4 sequentially selects each segment record SR.001-SR.N step 1202 and sequentially renders each segment record SR.001-SR.N in step 1210 that references or includes the user selected tag T.001-T.N detected in step 1108 . The user prompts the ebook reader 4 to proceed onto a succeeding segment record SR.001-SR.N in step 1214 . The ebook reader 4 will continue incrementing the segment counter CS in repeated execution of steps 1202 through 1214 until either (a.) the segment counter becomes equal to or exceeds a maximum segment count N; or (b.) the user enters a command to stop rendering segments SG.001-SG.N in either step 1206 or step 1214 .
[0077] Referring now generally to the Figures and particularly to FIG. 13 , FIG. 13 is a flowchart of a third preferred embodiment of aspects of the invented method applying a user selected tag T.001-T.N as executable by the ebook reader 4 in interaction with the reader, whereby the reader directs the ebook reader 4 to select segments SG.001-SG.N associated with an alternate tag T.001-T.N for rendering after the reader previously having selected a first tag T.001-T.N in a previous execution of step 1108 . During a rendering in step 1210 of a segment SG.001-SG.N, the user queries whether any other segment records SR.001-SR.N are associated with a same node ND.001-ND.N as the segment record SR.002-SR.N selected in the most recent execution of step 1210 . If no additional associated segment records SR.001-SR.N are determined in step 1304 , the ebook reader 4 proceeds on to step 1306 and reports to the user a rendered message to that effect. If at least one additional associated segment record SR.001-SR.N is determined in step 1304 , the ebook reader 4 proceeds on to step 1308 and render a message indicating the additional tag(s) T.001-T.N in step 1308 .
[0078] The ebook reader 4 determines in step 1310 whether the reader has selected a different tag T.001-T.N than applied in the most recent execution of step 1210 . When the ebook reader 4 determines in step 1310 that the reader has selected a new tag T.001-T.N, the ebook reader 4 renders the segment SG.001-SG.N of the segment record SR.001-SR.N comprising the tag T.001-T.N selected in step 1310 . As directed by the reader, the ebook reader 4 ceases rendering the segment SG.001-SG.N of step 1312 , and then proceeds from step 1314 to step 1206 , and thereafter selects segments SG.001-SG.N for rendering that include the newly selected tag of step 1310 in further implementations of steps 1202 through 1214 .
[0079] Referring now generally to the Figures and particularly to FIG. 14 , FIG. 14 is a flowchart of a fourth preferred embodiment of aspects of the invented method applying a user selected tag T.001-T.N as executable by the ebook reader 4 in interaction with the reader, whereby the reader directs the ebook reader 4 to follow an alternate tag T.001-T.N after initially selecting out segment records SR.001-SR.N that include or reference the default tag T.DEF.
[0080] During a rendering in step 1120 of a segment SG.001-SG.N, the user queries whether any other segment records SR.001-SR.N are associated with a same node ND.001-ND.N as the segment record SR.002-SR.N selected in the most recent execution of step 1120 . If no additional associated segment records SR.001-SR.N are determined in step 1404 , the ebook reader 4 proceeds on to step 1406 and reports to the user a rendered message to that effect. If at least one additional associated segment record SR.001-SR.N is determined in step 1404 , the ebook reader 4 proceeds on to step 1408 and render a message indicating the additional tag(s) T.001-T.N in step 1408 .
[0081] The ebook reader 4 determines in step 1410 whether the reader has selected a different tag T.001-T.N than applied in the most recent execution of step 1120 . When the ebook reader 4 determines in step 1410 that the reader has selected a new tag T.001-T.N, the ebook reader 4 renders the segment SG.001-SG.N of the segment record SR.001-SR.N comprising the tag T.001-T.N selected in step 1410 . As directed by the reader, the ebook reader 4 ceases rendering the segment SG.001-SG.N of step 1412 , and then proceeds from step 1414 to step 1116 , and thereafter selects segments SG.001-SG.N for rendering that include the newly selected tag of step 1410 in further implementations of steps 1112 through 1122 .
[0082] Referring now generally to the Figures and particularly to FIG. 15 , FIG. 15 is an illustration of a user interface 1500 of the ebook reader 4 as rendered on the ebook reader display screen 5 under as directed by user interaction and the ebook reader system software SW.1. In this exemplary illustration, a selected text segment SG.802 that is stored within or associated with the exemplary segment record SR.802 is rendered. The current tag T.04, as previously selected by the reader, and that the ebook reader software SW.1 is therefore currently following, is indicated by a first tab label TAB.1500. Additional tags T.02 & T.BILL comprised within or referenced by the exemplary segment record SR.802 are presented respectively by two additional tab labels TAB.1502A and TAB.1502B. In further addition, a fourth tag T.06 of an alternate segment record SR.806 that is associated with a same node ND.902 as is the currently rendered segment SG.802 is indicated by a fourth tab label TAB.1502C.
[0083] The user interface 1500 further includes command three command buttons 1504 , 1506 & 1508 and a search string input and activation box 1510 . The reader may direct the ebook reader 4 to proceed to render a next segment SG.810 in sequentially following the second tag T.04 by activating the NEXT command button 1506 . Alternatively, the reader may direct the ebook reader 4 to proceed to render a previous segment SG.808 in following the second tag T.04 in reverse sequence by activating the PREVIOUS command button 1504 . Additionally, the reader may direct the ebook reader 4 to cease to render segments SG.001-SG.N by selecting the REST/END command button 1508 . Yet alternatively, the ebook reader 4 may enter a textual search string in the string input and activation box 1510 and then activate this box 1510 to direct the ebook reader software SW.1 to find and report instances of the entered string in the ebook 2 .
[0084] The reader may further direct the ebook reader 4 to render an alternate segment SG.806 by selecting a nodal tab, e.g. fourth tab label TAB.1502C that represents an alternative segment SG.806 that is associated by a node ND.902 with the currently rendered segment SG.802. When an alternate segment record SR.001-SR.N is selected by the reader, the newly selected segment SG.001-SG.N of that selected record SR.001-SR.N is then rendered in the ebook display screen 5 and the current tab label TAB.1500 is revised to reference the newly accessed segment record SR.001-SR.N. For example, should the reader select the third tab label TAB.1502C when rendering the exemplary segment SG.802, the ebook reader SW.1 would react by rendering the alternate text SG.806 of segment record SR.806 and alter the first tab label TAB.1500 to reference both the alternate tag T.06 and the segment record SR.806 that comprises the newly rendered segment SG.806. The additional tab labels TAB.1502A-1502C are also then updated to reference the tab associations of the newly selected segment record SR.806. The command buttons of NEXT 1500 A and PREVIOUS 1500 B would then track the tag T.06 newly referenced by the first TAB.1500.
[0085] Referring now generally to the Figures and particularly to FIG. 16 , FIG. 16 is an illustration of a second user interface 1600 (or “UI” 1600 ) of the ebook reader 4 as rendered on the ebook reader display screen 5 and generated by the ebook reader system software SW.1 in interaction of the ebook reader 4 with the user. In this exemplary illustration of FIG. 16 , a selected text 1602 of an exemplary segment SG.810 that is stored within or associated with the exemplary subsequent segment record SR.810 is rendered in the ebook display screen 5 . A previous button 1604 and a next button 1606 are visually rendered in the display screen 5 and enable the user to respectively select the previous segment record SR.802 or the next segment record SR.812 of the first thread TH.04 for deriving a next or following rendering of text 1602 in the display screen 5 . Label buttons 1610 - 1622 enable the user to make choices to select alternate tags T.01-T.N and thereby follow alternate threads TH.1-TH.3 and TH.5-TH.N or to continue to follow a selected thread TH.1-TH.N and render text 1602 and images selected from or associated with segment records SR.001-SR.N. A visually rendered home button 1624 enables the user to direct the ebook reader 4 to return to displaying a home page. An informational text 1626 informs the user about the current ebook 2 being rendered and may provide information concerning the currently rendered text 1602 in relation to the entire ebook 2 . A visually rendered scroll control 1628 allows the user to direct the ebook reader 4 to render text 1602 from a single segment record SR.001-SR.N or of a currently selected thread TH.1-TH.N.
[0086] The label buttons 1608 - 1622 may optionally or additionally (a.) be visually shaded or affected to indicate which tag T.01-T.N is being currently followed, e.g., character label CHAR.1 1608 and location label LOC.1 1610 ; (b.) about other tags T.01-T.N with which the currently rendered text 1602 is associated, e.g. second character label CHAR.2 1612 and third location label LOC.3 1622 ; and/or additional labels 1614 - 1620 that are available within the ebook 2 and associated with different tags.
[0087] Referring now generally to the Figures and particularly to FIG. 17 , FIG. 17 is an illustration of a tag to label table 1700 that separately associates (a.) rendered labels 1610 - 1622 and tabs 1500 , 1504 , 1506 1502 A- 1502 C with (b.) tags T.01-T.N. Each label/tab to tag pair has a unique identifier PAIRID.1-PAIR.DEF.
[0088] It is understood that certain tags are durably associated with individual labels, for example a second location label LOC.2 is durably related to a ninth tag T.09, a sixth character label CHAR.6 is durably related to a fifth tag T.05, and a default label LABEL.DEF with the default tag T.DEFAULT in accordance with the second UI 1600 . It is further understood that the ebook system software SW.1 may alternately or additionally alter the associations of tags T.01-T.N with tabs 1500 - 1508 in accordance with the user interface 1500 .
[0089] Referring now generally to the Figures and particularly to FIG. 18 , FIG. 18 is a software flowchart of additional optional aspects of the system software SW.1 of the ebook reader 4 . The ebook reader 4 renders text and images 802 in step 18 . 02 from the most recently selected segment record SR.001-SR.N, for example the second exemplary segment SG.802 of the second exemplary segment record SR.802. In step 18 . 04 the ebook reader 4 determines whether a label or tab of the as rendered on the display 5 has been selected by the user. When the ebook reader 4 determines in step 18 . 04 that no tab or label has been selected by the user, the ebook reader 4 proceeds on step 18 . 06 and to determine whether to continue rendering content from the most recently selected segment record or to proceed on to step 18 . 08 and to perform alternate computational processes. The ebook reader 4 more proceed from step 18 . 06 to is step 18 . 08 on the basis of (a.) a time out condition; (b.) a receipt of a detection of a user selection of the REST/END label 1508 ; or (c.) a receipt of a power down command down from the user.
[0090] When the ebook reader 4 proceeds from step 18 . 06 to step 18 . 02 , the ebook reader 4 continues to render the content from most recently selected segment record SR.001-SR.N. When the ebook reader 4 determines in step 18 . 04 a tab or label selection by the user has been detected, the ebook reader 4 proceeds on step 18 . 10 and to determine whether a next segment record SR.001-SR.N of the same thread TH.01-TH.N of the segment record currently being rendered shall be rendered in a following execution of step 18 . 02 . Alternatively, the ebook reader 4 determines in step 18 . 12 to determine whether a previous segment record SR.001-SR.N of the same thread TH.01-TH.N of the segment record currently being rendered shall be rendered in a following execution of step 18 . 02 . Still alternatively, the ebook reader 4 determines in step 18 . 14 if the user has indicated that an segment record SR.01-N of an alternate tag T.01-T.N shall be selected for rendering. When the ebook reader 4 determines in step 18 . 14 that a segment record SR.01-SR.N of a tag T.01-T.N or thread TH.01-TH.N different from the selected tag T.01-T.MN or Thread TH.01_TH.N of the most recently rendered record, the ebook reader 4 references the table 1700 to relate the selected tab 1500 , 1502 A- 1502 C or label 1610 - 1622 to a tag T.01-T.N.
[0091] FIG. 19 is a schematic diagram of the ebook editing system 200 and/or ebook publishing system 600 . The ebook editing system 200 may be or comprise (a.) a network-communications enabled THINKSTATION WORKSTATION™ notebook computer marketed by Lenovo, Inc. of Morrisville, N.C.; (b.) a NIVEUS 5200 computer workstation marketed by Penguin Computing of Fremont, Calif. and running a LINUX™ operating system or a UNIX™ operating system; (c.) a network-communications enabled personal computer configured for running WINDOWS XP™, VISTA™ or WINDOWS 7™ operating system marketed by Microsoft Corporation of Redmond, Wash.; (d.) a MACBOOK PRO ™ personal computer as marketed by Apple, Inc. of Cupertino, Calif.; (e.) an IPAD™ tablet computer as marketed by Apple, Inc. of Cupertino, Calif.; (f.) an IPHONE™ cellular telephone as marketed by Apple, Inc. of Cupertino, Calif.; (g.) an HTC TITAN II™ cellular telephone as marketed by AT&T, Inc. of Dallas, Tex. and running a WINDOWS 7™ operating system as marketed by Microsoft Corporation of Redmond, Wash.; (h.) a GALAXY NEXUS™ smart phone as marketed by Samsung Group of Seoul, Republic of Korea or and running an ANDROID™; (i.) a TOUGHPAD™ tablet computer as marketed by Panasonic Corporation of Kadoma, Osaka, Japan and running an ANDROID ™ operating system as marketed by Google, Inc. of Mountain View, Calif.; or (j.) other suitable computational system or electronic communications device known in the art known in the art.
[0092] The editing system 200 A central processing unit is bi-directionally communicatively coupled by a communications bus 200 B to a display module 200 C, an input module 200 D, a wireless communications interface module 200 E, a system memory 200 F, an optional touch screen input 200 G, an optional firmware 200 H and/or an optional electronic media read/write module 2001 . The electronic media read/write module 2001 and an electronic media 1902 are selected to enable reading and writing of the ebook 2 to and from the editing system 200 . The editing system software SW.5 enables the editing system 200 to the perform the aspects of the invented method as disclosed herein in the Figures and accompanying text. The network 1900 may be or comprise the Internet, a telephony network, and/or other computer electronic communications network.
[0093] FIG. 20 is a schematic diagram of an ebook reader 4 . The ebook reader 4 may be or comprise (a.) a KINDLE ebook reader as marketed by Amazon, Inc. of Seattle, Wash.; (b.) a NOOK ebook reader as marketed by Barnes & Noble, Inc. of New York, N.Y.; (c.) an IPHONE™ cellular telephone as marketed by Apple, Inc. of Cupertino; (d.) an IPAD™ tablet computer adapted for generation of digitized photographic documents and capable of bi-directional communications via the telephony network and the Internet 6 as marketed by Apple, Inc. of Cupertino, Calif.; (e.) an HTC TITAN H™ cellular telephone as marketed by AT&T, Inc. of Dallas, Tex. and running a WINDOWS 7™ operating system as marketed by Microsoft Corporation of Redmond, Wash.; (f.) a GALAXY NEXUS ™ smart phone as marketed by Samsung Group of Seoul, Republic of Korea and running an ANDROID™ operating system as marketed by Google, Inc. of Mountain View, Calif.; (g.) a TOUGHPAD™ tablet computer as marketed by Panasonic Corporation of Kadoma, Osaka, Japan and running an ANDROID™ operating system as marketed by Google, Inc. of Mountain View, Calif.; or (h.) other suitable text display system known in the art.
[0094] The ebook reader central processing unit 4 B is bi-directionally communicatively coupled by a reader communications bus 4 B to a display module 4 C and the touch screen display 5 , a reader input module 4 D, a reader wireless communications interface module 4 E, the reader system memory 4 A, an optional firmware 4 F and/or an optional reader electronic media read/write module 4 G. The electronic media read/write module 4 G and the electronic media 1902 are optionally selected to enable reading and writing of the ebook 2 to and from the ebook reader 4 . The ebook reader system software SW.1 enables the ebook reader 4 to perform the aspects of the invented method as disclosed herein in the Figures and accompanying text. A first GUI software SW.6 enables the first user interface and process of FIG. 15 and the user interaction as disclosed in the accompanying text. A second GUI software SW.7 enables the process of the second UI of FIG. 16 and the user interaction as disclosed in the accompanying text.
[0095] One skilled in the art will recognize that the foregoing examples are not to be taken in a limiting sense and are simply illustrative of at least some of the aspects of the present invention.
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The present invention provides a way of parsing into tagged segments of texts and therefrom accessing multi-tagged literature. Multi-tagged literature comprises multiple narrative threads that may each occur simultaneously within a narrative or historical timeline, thereby allowing the reader to switch back and forth between various aspects of a text and optionally follow separate threads. In certain versions, the invented system includes an editing interface and a reader software. The editing interface allows for the manipulation of both imported text, newly input and/or newly authored text, and enables a user to populate a file with the text in combination with functional software code. The reader software directs the ebook display device to both render the text and allow the user to traverse the text in a variety of ways as directed by input to the ebook display device of commands and selections.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The disclosure of Japanese Patent Application No. 2015-030669 filed on Feb. 19, 2015 including the specification, drawings, and abstract is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a structure for a vibration damping wall mainly used in wooden buildings or steel structure buildings for reducing an earthquake force that exerts on buildings to improve the horizontal capacity of structural frames, as well as a method of connecting vibration damping devices.
[0004] 2. Description of the Related Art
[0005] Techniques relating to vibration damping devices installed to structural frames of buildings and techniques relating to methods of connecting the vibration damping devices and the structural frame for preventing buildings from destruction upon occurrence of huge earthquake have been provided so far (refer to JP-A No. 2009-275473).
[0006] FIG. 6 and FIG. 7 illustrate a vibration damping device and a method of connecting vibration damping devices and a structural frame shown in JP-A No. 2009-275473 of a building. FIG. 6 illustrates a structure frame 60 of a building. The structural frame 60 comprises a foundation 61 , a beam 62 and vertical members 63 (first vertical member 63 a and a second vertical member 63 b ). A first vibration damping device 70 a is attached about at the midway of a first vertical member 63 a by fixing means such as bolts or screws and a second vibration damping device 70 b is attached about at the midway of a second vertical member 63 a by fixing means such as bolts or screws.
[0007] Corner fittings 71 are fitted each by way of fixing means such as bolts or screws at four corners defined by the first vertical member 63 a and the second vertical member 63 b , the foundation 61 , and the beam 62 . The four corner fittings 71 and the vibration damping devices 70 a and 70 b are connected in an X-form by brace members 72 such as steel pipe brace members as illustrates in FIG. 7 .
[0008] The vibration damping device 70 is usually in a state as illustrated in FIG. 8A and, when an earthquake occurs, the lateral sides 73 expand or contract by the deformation of bend portions of the vibration damping device 70 as illustrated in FIGS. 8B and 8C due to earthquake shaking. Then, the earthquake energy is decayed by repeating expansion/contraction to absorb swaying of an entire building structure and prevent the building from destruction.
SUMMARY OF THE INVENTION
[0009] Destruction of a building can be prevented effectively by installing the vibration damping devices 70 to the vertical members 63 and connecting them by brace members 72 as described above.
[0010] However, along with reinforcement and scale enlargement of structural materials in recent years, their fixed loads have been increased. Thus, a shaking force due to the earthquake that exerts on the structural frame 60 of the building has been increased and the force exerting on the vibration damping device 70 has also been increased compared with existent cases. Accordingly, in a state of FIG. 8B , the upper lateral side 73 contracts more largely than usual and the lower lateral side 73 extends more largely than usual. In a state of FIG. 8C , the upper lateral side extends more largely than usual and the lower lateral side 73 contracts more largely than usual. When such large expansion and contraction repeat, the bending stress on the lateral sides 73 exceeds a limit and plastic cracks are generated to damage the vibration damping device 70 . Then, the vibration damping device 70 no more functions, which may possibly destroy the building finally.
[0011] The present invention intends to solve such a problem and provide a vibration damping wall structure and a method of connecting the vibration damping devices, not leading to destruction of the building even when the earthquake force increases.
[0012] In order to solve the subject, the present invention intends to provide a vibration damping wall structure including;
[0013] a plurality of first vibration damping devices attached to a first vertical member that constitutes a structural frame of a building,
[0014] a plurality of second vibration damping devices attached to a second vertical member that constitutes the structural frame so as to oppose the first vibration damping devices,
[0015] a first brace member for connecting the first vertical member and the second vibration damping devices,
[0016] a second brace member for connecting the second vertical member and the first vibration damping devices,
[0017] lateral connection members for connecting the first vibration damping devices and the second vibration damping devices opposing thereto,
[0018] a first vertical connection member for connecting the plurality of the first vibration damping devices to each other, and
[0019] a second vertical connection member for connecting the plurality of the second vibration damping devices to each other.
[0020] In the vibration damping wall structure of the present invention, the plurality of the first vibration damping devices attached to the first vertical member that constitutes the structural frame of the building and the plurality of the second vibration damping devices attached to the second vertical member that constitutes the structural frame so as to oppose the first vibration damping devices are connected by the lateral connection members and the vertical connection members.
[0021] Thus, earthquake shaking is transferred uniformly from the vertical members by way of the brace members and the lateral connection members and the vertical connection members to the vibration damping devices.
[0022] For solving the subject described above, the present invention also provides a method of connecting vibration damping devices of connecting a plurality of first vibration damping devices attached to a first vertical member that constitutes a structural frame of a building and a plurality of second vibration damping devices attached to a second vertical member that constitutes the structural frame so as to oppose the first vibration damping devices, the method including:
[0023] connecting the first vertical members and the second vibration damping devices by a first brace member,
[0024] connecting the second vertical member and the second vibration damping devices by a second brace member,
[0025] connecting the first vibration damping devices and the second vibration damping devices opposing the first vibration damping devices by lateral connection members,
[0026] connecting the plurality of the first vibration damping devices to each other by the first vertical connection member and
[0027] connecting the plurality of the second vibration damping devices to each other by the second vertical connection member.
[0028] In the method of connecting the vibration damping devices of the present invention, the plurality of the first vibration damping devices attached to the first vertical member that constitutes the structural frame of the building and the plurality of the second vibration damping devices attached to the second vertical member that constitutes the structural frame so as to oppose the first vibration damping devices are connected by the lateral connection members and the vertical connection members.
[0029] Thus, earthquake shaking is transferred from the vertical member by way of the brace member and the lateral connection member and the vertical connection member uniformly to all of the vibration damping devices.
[0030] According to the present invention, the earthquake shaking is transferred from the vertical members by way of the brace members and the lateral connection members and the vertical connection members to all of the vibration damping devices. In this condition, since deleterious deformation of the upper plane of the vibration damping device is restricted by the lateral connection members and the vertical connection members, expansion and contraction in the direction of the height of the lateral side is decreased to reduce the burden on the lateral bend portion 74 .
[0031] Thus, plastic cracks are not generated on the lateral side of the vibration damping device, and the vibration damping device does not suffer from damages and deformation of the structural frame of the building can be reduced finally. That is, by the new method of connecting the vibration damping devices and the brace members, the lateral connection members, and the vertical connection members, since they are operationally associated and restrict the swaying by earthquake, the remarkable effect described above can be provided (this is to be described specifically in preferred embodiments).
DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0032] FIG. 1 is a front elevational view illustrating a vibration damping wall structure and a method of connecting vibration damping devices according to a first embodiment of the present invention;
[0033] FIG. 2 is a front elevational view illustrating a mode of transmitting earthquake shaking;
[0034] FIG. 3 is a view illustrating a state where a vibration damping device absorbs earthquake shaking;
[0035] FIG. 4 is a front elevational view of a damping device of a substantially Ω-shaped configuration;
[0036] FIG. 5 is a perspective view of a vibration damping device of a substantially π-shaped configuration;
[0037] FIG. 6 is a view illustrating an existent example of a vibration damping wall structure and a method of connecting vibration damping devices;
[0038] FIG. 7 is a view illustrating a connection portion of the vibration damping device;
[0039] FIGS. 8A-8C are views illustrating a state that the vibration damping device absorbs earthquake shaking;
[0040] FIG. 9 is a front elevational view illustrating a vibration damping wall structure and a method of connecting vibration damping devices according to a second embodiment of the present invention;
[0041] FIG. 10 is a front elevational view illustrating a transfer mode of earthquake shaking in the second embodiment; and
[0042] FIG. 11 is a view illustrating a state of attaching a vibration damping device and a connection plate of the second embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
First Embodiment
[0043] A first embodiment describes an example of a vibration damping wall structure and a method of connecting vibration damping devices in a wooden building.
[0044] For the first embodiment, FIG. 1 illustrates a vibration damping wall structure and a method of connecting vibration damping devices according to the present invention.
[0045] Since FIG. 1 shows a lot of constitutional elements that are identical with those of FIG. 6 explained as the prior art, identical reference numerals are used for identical constitutional elements and only the differences are to be explained.
[0046] This embodiment has a constitution as illustrated in FIG. 1 , which is different from the existent embodiment in FIG. 6 with respect to the followings.
[0000] (1) Vibration damping devices are provided each by one on the right and left not but provided each by two on the right and left. It is assumed here that
[0047] the vibration damping device provided to an upper portion of a vertical member 63 a is referred to as a damping device 70 a,
[0048] a vibration damping device provided at a lower portion of the vertical member 63 a is referred to as a vibration damping device 70 c,
[0049] a vibration damping device provided to the upper portion of a vertical member 63 b is referred to as a vibration damping device 70 b , and
[0050] a vibration damping device provided at a lower portion of the vertical member 63 b is referred to as a fourth vibration damping device 70 d.
[0000] (2) The vibration damping device 70 a and the vibration damping device 70 b are connected by a lateral connection member 1 a , and the vibration damping device 70 c and the vibration damping device 70 d are connected by a lateral connection member 1 b.
(3) The vibration damping device 70 a and the vibration damping device 70 c are connected by a vertical connection member 2 a , and the vibration damping device 70 b and the vibration damping device 70 d are connected by a vertical connection member 2 b.
[0051] Then, a step of connecting the members of the present invention is to be described.
[0052] First, as a first step, corner fittings 71 are mounted to corners of the structural plane that constitutes the structural frame 60 of a building respectively and, subsequently, the vibration damping device 70 a is attached to a first vertical member 63 a by about 250 mm to 500 mm above the center of the first vertical member 63 a . The vibration damping device 70 b is attached to the second vertical member 63 b at a position opposing thereto. The vibration damping device 70 c is attached to the first vertical member 63 a at a position about 250 mm to 500 mm below the center of the first vertical member. The vibration damping device 70 d is attached to the second vertical member 63 b at a position opposing thereto.
[0053] As a second step, crossing steel pipe braces (braces 72 ) are attached to upper and lower stages of the structural plane each at a position between each of the corner fittings 71 and each of the vibration damping devices 70 .
[0054] As a third step, the vibration damping device 70 a and the vibration damping device 70 b are connected by the lateral connection members 1 a and the vibration damping device 70 c and the vibration damping device 70 d are connected by the lateral connection members 1 b respectively. Further, the vibration damping device 70 a and the vibration damping device 70 c are connected by the vertical connection member 2 a and the vibration damping device 70 b and the vibration damping device 70 d are connected by the vertical connection member respectively.
[0055] As a fourth step, after adjusting the plumbing of the structural plane, connection points are tightly connected by high tension bolts and nuts thereby providing a vibration damping wall structural plane.
[0056] Then, the function and the effect of the first embodiment are to be described with reference to FIG. 2 .
[0057] In FIG. 2 , stress of an earthquake force is transmitted from the first vertical member 63 a and the second vertical member 63 b through the upper brace member 72 (upper cross steel pipe brace member) and the lower brace member 72 (lower cross steel pipe brace member) to the lateral connection members 1 .
[0058] In this condition, the lateral connection member 1 a operates in a mode like crank movement by vertical sliding of each of the vibration damping devices 70 a and 70 b in the direction of the height of the structure plane.
[0059] Thus, the lateral connection member 1 a restricts excess deformation of the upper plane 28 a by sliding like a piston movement while pressing the upper plane of the vibration damping devices 70 downward upon forward pressing and pulling upward the upper plane upon backward pressing (sliding only for a relative position without changing an absolute distance in the upper plane) ( FIG. 4 ).
[0060] Accordingly, excess deformation of the vibration damping device 70 can be restricted to a necessary and sufficient extent even when the support member 22 ( FIG. 4 ) is not present and the bearing performance can also be enhanced while improving the vibration damping performance.
[0061] The restrictive phenomenon described above is due to the crank movement of the lateral connection members.
[0062] As described above, the stress exerting from the brace member 72 , and the vertical connection member 1 and the lateral connection member 2 to extensions thereof by the continuous sliding of the upper plane 28 a ( 28 b ) ( FIG. 4 ) of the vibration damping device does not converge to a point since the lateral side bend portion 74 ( FIGS. 8A-8C ) as a fulcrum of stress transmission moves vertically and right to left like a roller.
[0063] By the remarkable effect of dispersing the stress exerted from the brace member 72 , and the vertical connection member 1 and the lateral connection member 2 over a wide range of a bottom plate 29 of the vibration damping device 70 , the reaction caused by an excessive earthquake force is received substantially uniformly over the entire bottom area of the bottom plate 29 and, as a result, damages that may likely to occur by bending deformation of the vertical member 63 to the the vibration damping device attached at about the center of the vertical member 63 of the structural plane frame of the building can be prevented effectively.
[0064] Meanwhile, the sliding movement of the vibration damping devices 70 a and 70 b brings about vertical movement of the vertical connection members 2 a and 2 b . The vibration damping devices 70 c and 70 d also operate simultaneously to induce the crank movement of the lateral connection member 1 b thereby causing the damping phenomena described above to reliably restrict the excess deformation of the vibration damping device 70 by co-operation of upper and lower vibration damping devices, so that the vibration damping effect can be improved and bearing performance can be enhanced.
[0065] As described above, since the earthquake force is transmitted further uniformly to the vibration damping devices 70 entirely, expansion and contraction of the lateral sides 73 are decreased further ( FIG. 3 ) compared with those in FIGS. 8A-8C , a risk of damaging the vibration damping device 70 by plastic cracks can be decreased further and, in addition, destruction of the vertical member 63 can be decreased remarkably. The material and the shape of the lateral connection member 1 and the vertical connection member 2 may be identical with those of the brace member 72 , or they may comprise other rod-like members.
[0066] Then, the vibration damping device 70 is to be described specifically. The vibration damping device 70 includes two types depending on whether the device has a support member 22 or not. In this embodiment, a vibration damping device of a type having the support member 22 is to be described specifically. FIG. 4 illustrates a substantially Ω-shaped vibration damping device 70 having a support member 22 . The substantially Ω-shaped vibration damping device 70 comprises a vibration damping element 21 made of a low yield point steel and a support member 22 for supporting the vibration damping element 21 .
[0067] The vibration damping element 21 comprises a steel strip that causes plastic deformation when undergoing a stress beyond an elastic limit and has a first attaching plane 23 a and a second attaching plane 24 a for attachment to a vertical member 63 , a first rising portion 25 a rising from the inner end of the first attaching plane 23 a , a second rising portion 26 a rising from the inner end of a second attaching plane 24 a , and an upper plane 28 a that connects the first rising portion 25 a (lateral side 25 a ) and a second rising portion 26 a (lateral side 26 a ) and receives an earthquake shaking transmitted from the structural frame 60 by way of a brace member 72 and an attaching plate 27 . The vibration damping element 21 absorbs earthquake shaking as shown in FIG. 8B and FIG. 8C , thereby improving the earthquake resistance of a building.
[0068] The support member 22 is a cylindrical member. That is, the support member 22 has a first arcuate lateral side 31 and a second arcuate lateral side 32 and is disposed in a space surrounded by an upper plane 28 a , the first rising portion 25 a and the second rising portion 26 a . The first lateral side 31 is disposed in the inside near the first bend portion 33 formed of the first rising portion 25 a and the upper plane 28 a , and the second lateral side 32 is disposed in the inside near a second bend portion 34 formed of the second rising portion 26 a and the upper plane 28 a.
[0069] By the provision of the support member 22 , when an earthquake shaking is transmitted to the vibration damping device 21 , excess deformation of the first bend portion 33 and the second bend portion 34 is supported and restricted more reliably by the support member 22 and, accordingly, damages of the vibration damping device 70 caused by generation of plastic cracks can be prevented.
[0070] FIG. 5 illustrates a substantially π-shaped vibration damping device 70 .
[0071] The constitution of the substantially π-shaped vibration damping device 70 is similar to that of the substantially Ω-shaped vibration damping device 70 in FIG. 4 , but is different therefrom with respect to the following points. That is, in the substantially π-shaped vibration damping device 70 , each of a first rising portion 25 b and a second rising portion 26 b is formed by bending a steel strip made of low yielding point steel into a substantially L-angled shape being rounded at a corner, and fixed on the bottom plate 29 such that angled edges are outwarded and opposed at a predetermined distance.
[0072] Compared with the substantially Ω-shaped vibration damping device, since the π-shaped vibration damping device 70 has only two opposed portions (first rising portion 25 b and the second rising portion 26 b ) formed by bending the lower portions, earthquake shaking is directly transmitted to the opposed portions. Accordingly, the device of this type has an advantage that the first rising portion 25 b and the second rising portion 26 b can be deformed simply and, on the other hand, the support member 22 has to be mounted for restricting excess deformation. Excess deformation less occurs by so much as the shape is simple and short.
[0073] On the other hand, the upper plane 28 b is made of common steel (SS 330 •SS 400 •SS 540 , etc.) and has a constitution of intending to exclusively rely on the rigidity and the strength of the upper plane for firmly holding an attaching plate 35 that fixes chord members such as the brace member 72 , the lateral connection member 1 , the vertical connection member 2 , etc. Then, for making the joint with the L-shaped angle member more firmly, each of the top ends is hooked in the direction of the first attaching plane 23 b and the second attaching 24 b.
Second Embodiment
[0074] A second embodiment describes an example of a vibration damping wall structure and a method of connecting vibration damping devices.
[0075] In this embodiment, FIG. 9 illustrates a vibration damping wall structure and a method of connecting vibration damping devices according to the present invention.
[0076] Since FIG. 9 shows a lot of constitutional elements that are identical with those of FIG. 1 explained as the first embodiment, identical reference numerals are used for identical constitutional elements and only the differences are to be explained.
[0077] The second embodiment has a constitution as illustrated in FIG. 9 , which is different from the first embodiment (shown in FIG. 1 ) in that the vibration damping devices 70 are connected not by the lateral connection member 1 and the vertical connection member 2 but by a connection plate member 36 comprising a structural plywood or a metal plate or a composite plate integrally.
[0078] The connection plate member 36 is joined at each of corners to an attaching plate 27 of a vibration damping device 70 by means of high tension bolts 75 and nuts in the same manner as in the case of the lateral connection member 1 and the vertical connection member 2 of the first embodiment. In the first embodiment, a rectangular frame of an instable structure is formed by the lateral connection member 1 and the vertical connection member 2 , which tends to be deformed into a parallel piped shape following the deformation of the building upon exertion of an earthquake force. On the other hand, in the second embodiment, the connection plate member 36 per se is a plate member having a large in-plane rigidity, which repeats rotational movement swinging right and left while keeping a quadrangular shape following the sliding movement of the upper plane 28 of the vibration damping device 70 due to deformation of the building upon exertion of the earthquake force.
[0079] Next, the function and the effect of this embodiment are to be described with reference to FIG. 10 .
[0080] In FIG. 10 , stress of an earthquake force is transmitted from the first vertical member 63 a and the second vertical member 63 b by way of the upper brace member 72 (upper cross steel pipe brace) and the lower brace member 72 (lower cross steel pipe brace) by way of the vibration damping devices 70 to the connection plate member 36 .
[0081] In this condition, the connection plate member 36 moves vertically and right to left by vertical sliding movement of the upper planes 28 a and 28 b of each of the vibration damping devices 70 a and 70 b in the direction of the height of the wall plane (vertical direction).
[0082] Thus, since the connection plate member 36 slides the upper planes 28 a and 28 b of the vibration damping devices 70 while pressing downward upon forward pressing and pulling the upper planes upward upon backward pressing (sliding only for a position without changing an absolute distance between the upper planes).
[0083] Accordingly, excess deformation of the vibration damping device 70 is restricted to a necessary and sufficient extent and also the bearing performance can be enhanced while improving the vibration damping performance even when the support member 22 ( FIG. 4 ) is not present in the same manner as in the first embodiment. The damping phenomenon described above is due to the action of the connection plate member 36 .
[0084] As described above, stress exerting from the brace member 72 and the connection plate member 36 to the extensions thereof by continuous sliding of the upper plane 28 a of the vibration damping device ( FIG. 11 ) does not converge to a point since the lateral side bend portion 74 ( FIG. 8 ) moves vertically and right to left following the sliding movement like a roller in the same manner as in the first embodiment.
[0085] Accordingly, by the remarkable effect that the stress exerting from the brace member 72 and the connection plate member 36 to the extensions thereof less converges to a point of the vertical member 63 of the building structure frame but disperses over a wide range of the bottom plate 29 of the vibration damping device 70 , the reaction caused by an excessive earthquake force is dispersed at random over the entire bottom of the bottom plate 29 and, as a result, damages caused by the bending deformation of the vertical member 63 that tends to be formed in the vibration damping device attached near the central portion of the vertical member 63 of the structural wall frame of the building can be prevented effectively.
[0086] On the other hand, the sliding movement of the upper plane 28 a of the vibration damping device 70 a and the upper plane 28 b of the vibration damping device 70 b brings about a vertical movement of the connection plate member 36 in the longitudinal direction (vertical direction), in which the vibration damping devices 70 c and 70 d operates simultaneously thereby inducing the lateral (horizontal) rotational action of the connection plate member 36 , which can control the over deformation of the vibration damping device 70 reliably by the cooperation of the upper and lower vibration damping devices 70 , thereby improving the vibration damping performance and enhancing the bearing performance.
[0087] As described above, upon occurrence of an earthquake, since the action thereof is transmitted entirely by the vibration control devices 70 and the connection plate member 36 more uniformly, expansion and contraction of the lateral side 73 are decreased compared with those in the prior art ( FIGS. 8A-8C ), and the risk of damaging the vibration damping device 70 by plastic cracks can be decreased further. As a result, destruction of the vertical member 63 of the building structural frame 60 by the damages of the vibration damping device 70 can be avoided and the earthquake energy can be absorbed and decayed effectively.
[0088] In addition, for the connection plate member 36 , it is not particularly necessary to provide a plate member designed previously to a prescribed size and the connections plate member 36 sized in situ depending on the condition of the spot can be manufactured and assembled and the cost can be decreased.
DESCRIPTION OF REFERENCE SIGNS
[0000]
P external force
1 a , 1 b lateral connection member
2 a , 2 b vertical connection member
21 vibration damping element
22 support member
23 a , 23 b first attaching plane
24 a , 24 b second attaching plane
25 a , 25 b first rising portion
26 b , 26 b second rising portion
27 attaching plate
28 a , 28 b upper plane
29 bottom plate
31 first lateral side
32 second lateral side
33 first bend portion
34 second bend portion
35 attaching plate
36 connection plate member
60 structural frame
61 foundation
62 beam
63 a , 63 b vertical member
70 ( 70 a , 70 b , 70 c , 70 d ) vibration damping device
71 corner fitting
72 brace member
73 lateral side
74 Bend portion of lateral side
75 high tension bolt
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A robust vibration damping device not suffering from destruction even when an earthquake force is increased.
A vibration damping wall structure includes a structural frame comprising a foundation, a beam, and vertical members. One set of vibration damping devices are attached to a first vertical member, and another set of vibration damping devices are attached at positions respectively opposing the one set of vibration damping devices to a second vertical member. Each of the vibration damping devices is connected with the vertical member by way of a brace. The vibration damping devices in the one set and opposing vibration damping devices in another set are connected each other in a lateral direction by lateral connection members between each of the sets. Further, the vibration damping devices of each of the sets are connected each other in a vertical direction by the vertical connection members respectively in each of the sets.
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TECHNICAL FIELD
This invention relates to an automotive headliner and, more particularly, to a recyclable headliner comprised of 100% polyethylene terephthalate (PET) material and its method of manufacture.
BACKGROUND OF THE INVENTION
Prior art headliner configurations include those with foam cores bonded to a fabric decorative sheet as Set forth in U.S. Pat. Nos. 3,966,526 and 4,211,590; those with a fiberglass or corrugated paper reinforcement as set forth in U.S. Pat. No. 4,119,749; and those that include a thermoformed polyester fiber core covered by a fabric layer or by a foam layer of differing material as set forth respectively in U.S. Pat. Nos. 4,840,832 and 5,275,865.
In all such cases the headliners are comprised of different materials that are difficult to recycle.
The headliner of the present invention is made 100% from PET material capable of recycling by processes such as set forth in U.S. Pat. No. 5,225,130. While the '130 patent describes a process for reclaiming scrap PET material it does not disclose or suggest a solution of how to provide a headliner of a 100% PET material that will have desired strength properties.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a high strength automotive headliner that can be scrapped and recycled without separating the constituent parts thereof and to do so by an automotive headliner that consists 100% of PET material.
One feature of the present invention is to provide such an automotive headliner having a polymeric fiber batt of 100% PET material and including impressions forming reverse ribs of varying density of PET fibers filled with full density PET reinforcements.
Another feature of the present invention is to provide a method of manufacturing such headliners including forming the reverse ribs in the PET fibers by heating and compressing the PET fibers into a reverse rib configuration having ribs of varying density and either preforming the full density reinforcements and bonding them between the ribs or forming the ribs and then injecting molten full density PET material therebetween.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the present invention will be better understood and apparent with reference to the following detailed description taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a partial perspective phantom view of a vehicle with a headliner including the present invention;
FIG. 2 is a detailed fragmentary cross-sectional view showing a headliner constructed in accordance with a first embodiment of the invention;
FIG. 3 is a perspective view of a fiber batt preformed according to the invention;
FIG. 4 is a view similar to FIG. 2 showing one variant of a second embodiment of the invention;
FIG. 5 is a view similar to FIG. 2 showing a second variant of the second embodiment;
FIG. 6 is a view similar to FIG. 3 showing an alternative batt configuration;
FIG. 7 is a view similar to FIG. 2 showing one variant of a third embodiment of the invention; and
FIG. 8 is a view similar to FIG. 2 showing a second variant of the third embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A headliner for mounting across the underside of an automotive passenger compartment roof is generally shown at 10 in FIG. 1. The headliner 10 comprises a polymeric fiber batt, as is generally indicated at 12 in FIG. 3. The batt 12 is made up of 100% polyethylene terephthalate (PET) fibers, about 10% of which are low-melt fibers. The batt 12 has a smooth, cosmetic front side 14 that faces downward into the passenger compartment and, as shown in FIGS. 2, 4, 5, 7 and 8, a back side 16 that faces upward toward the underside of the vehicle roof. The batt 12 is formed into a downwardly-opening concave configuration and is shaped to fit across and adjacent the underside of the roof.
A cross section of a headliner constructed according to a first embodiment of the invention is shown in FIG. 2. FIGS. 4 and 5 show two variants of a second embodiment of the invention and FIGS. 7 and 8 show two variants of a third embodiment. Reference numerals with the designation prime (') in FIGS. 4 and 5 and the designation double-prime (") in FIGS. 7 and 8 indicate alternative configurations of elements that also appear in the first embodiment. Portions of the following description use reference numerals to refer to elements in the figures. If a portion of the description includes a reference numeral having no prime or double-prime designation, we intend that portion of the description to apply equally to elements in FIGS. 1-8 that are indicated by that reference numeral--both with and without a prime or double-prime designation.
As shown in FIG. 3, the back side 16 of the batt of the first and second embodiments comprises a plurality of impressions in the form of corrugations 18, or "reverse ribs", that extend across the batt back side 16. The corrugations 18 comprise a plurality of corrugation channels 20 disposed between and defining corrugation ribs 22. Between the corrugations 18 and the batt front side 14 are areas 24 of reduced batt thickness and correspondingly higher batt fiber density that act as reinforcing elements and stiffen the headliner 10.
As shown in FIG. 2, the first embodiment of the invention includes a skin of coarse fabric, i.e., a "scrim" layer 26 made of PET fibers that is bonded to the batt back side 16 and lays flat across the back side 16, spanning the corrugations 18. By bonding the scrim layer 26 to the batt back side 16 in such a way that it spans the corrugations 18, the scrim 26 imparts additional stiffness and shape-retention properties to the headliner 10. The scrim 26 does this by structurally reinforcing and holding the shape of each corrugation 18 against bending forces that might be applied to the headliner 10. As is best shown in FIG. 2, the bonded scrim layer 26 "caps-off" each corrugation channel 20 to form an elongated trapezoidal "torsion box" structure that resists bending and twisting forces.
Full-density extruded PET 27 fills each corrugation channel 20 between the batt back side 16 and the scrim layer 26. The full-density extruded PET 27 is heat-bonded to the low-melt fibers in the batt 12. The parallel rows of elongated full-density extruded PET filler material 27 follow the general curvature of the headliner 10 and act as structural arches supporting the concave shape of the headliner 10 after installation.
While the first and second embodiments include corrugations 18 formed into the batt back side 16 as shown in FIG. 3, variants of the first and second embodiment may additionally or alternatively include corrugations formed in the batt front side 14. Within the scope of this invention, other variants may also include, in the place of corrugations 18, a plurality of closely-spaced craters that define an "egg-crate"-type surface across the batt back side or front side as shown in FIG. 6.
Also within the scope of the present invention, the skin spread across the batt back side 16 of the first embodiment may be made of a PET film instead of a scrim layer 26. In other variants, the full-density extruded PET filler material 27 may be bonded to the batt 12 by an adhesive rather than by heat fusion. The adhesive may be any one of a number of suitable adhesives to include PET adhesive.
Other variants may omit the full-density extruded PET filler 27 altogether. Instead, the spaces formed between the PET scrim 26 and the PET batt 12, where the scrim 26 spans the channels 20 in the batt back side 16, may be left empty.
In the second embodiment of the present invention shown in FIGS. 4 and 5, extruded PET beams 28 are bonded into and along each corrugation channel 20 between the PET batt 12 and the PET scrim layer 26. FIG. 4 shows the second embodiment with "T" beams and FIG. 5 shows "I" beams bonded into each corrugation channel 20. In the second embodiment, the extruded beams 28 take the place of the full-density extruded PET filler material of the first embodiment and serve the same purpose of providing stiffness and rigidity to the headliner 10.
As shown in FIGS. 7 and 8, the third embodiment uses the same type of full-density extruded PET beams 28 as in the second embodiment but the beams 28 are bonded to the flat back side 16 of a PET batt 12 that has no corrugations 18 or craters. The PET beams 28 may have any suitable cross-sectional shape to include T-shaped beams as shown in FIG. 7 and I-shaped beams as shown in FIG. 8. The beams 28 may also be either partially or completely imbedded in the batt 12 as shown in FIG. 8.
In practice, a polymeric fiber batt 12, preferably comprising 100% PET fibers (10% of which are low melt fibers), is heated until the low-melt fibers melt. The fiber batt 12 is then placed in a press where it is formed and compressed into a contoured shape.
Within the press, cold platens form a plurality of impressions into the fiber batt back side 16 resulting in a plurality of high-density areas 24 of PET located between the impressions and the batt front side 14. The impressions are formed as elongated corrugation channels 20 of PET that define and are disposed between elongated corrugation ribs 22 of PET. The fiber batt 12 is then cooled until the low-melt fibers solidify. A PET scrim 26 or film layer is then bonded to the batt back side 16 with the scrim layer 26 spanning the impressions.
Full density extruded PET 27 is then heated, melted and injected into each corrugation channel 20 until each channel 20 is full of the melted PET material 27. The full density extruded PET 27 may be injected either before or after the scrim layer 26 is applied. The full density PET 27 adheres to the channel walls by causing the low melt fibers in the batt 12 to melt and co-mingle with the molten full density PET 27. Upon cooling and hardening, the full density extruded PET 27 formed within each channel 20 becomes an integral stiffening and rigidifying beam.
To form craters rather than channels 20 across the batt backside, the press platens are shaped to form crater-shaped depressions. Where PET adhesive is used to bond the full-density extruded PET within the depressions, the adhesive is applied along each depression prior to injecting the molten PET.
The PET T or I beams 28 may be either partially or fully embedded in the batt 12 rather than being bonded to a batt surface. In this case, the beams 28 are molded into the batt 12 either before or during the time when the batt 12 is formed within the press.
By this process one may form a headliner which is light, inexpensive, and sufficient rigid to hold its shape while spanning a passenger compartment ceiling. The various rigidifying features incorporated into the headliner using this process allow headliners to be constructed using 100% recycled PET materials.
If desired, PET cloth material can be used as a cover surface or first surface on the headliner. Further, while PET is the preferred material for recycling the whole headliner, the invention contemplates replacement of PET with a polymer that would be compatible with PET when passed through a recycling process.
This is an illustrative description of the invention using words of description rather than of limitation.
Obviously, many modifications and variations of this invention are possible in light of the above teachings. Within the scope of the claims, one may practice the invention other than as described.
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A recyclable automotive headliner consists 100% of polyethylene terephthalate (PET) material and includes reverse ribs of varying density of PET fibers filled with reinforcements of full density PET material. A method of manufacturing such headliners includes forming the reverse ribs in the PET fibers and either preforming the full density reinforcements and bonding them between the ribs or forming the ribs and then injecting molten full density PET material therebetween.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2008-0073164 (filed on Jul. 25, 2008), which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] FIGS. 1 to 3 are views illustrating manufacturing processes of a symmetric semiconductor device.
[0003] Referring to FIG. 1 , a device isolation region 11 is formed in a semiconductor substrate 10 through a Shallow Trench Isolation (STI) technique, and then an insulation layer 12 and a polysilicon layer 13 are stacked thereon. Based on the device isolation region 11 , one side of the semiconductor substrate 10 is a region where an N-type Metal Oxide Semiconductor (NMOS) device is to be formed, and the other side of the semiconductor substrate 10 is a region where a P-type MOS (PMOS) device is to be formed.
[0004] As shown in FIG. 2 , gate insulation layers 12 a and 12 b and gate electrodes 13 a and 13 b are formed in the NMOS region and the PMOS region, respectively, by patterning the insulation layer 12 and the polysilicon layer 13 . Then, symmetric Lightly Doped Drain (LDD) regions 14 a and 14 b are formed through an ion implantation process.
[0005] Next, as shown in FIG. 3 , spacers 16 a and 16 b are formed on the sidewalls of the gate electrodes 13 a and 13 b , and source and drain regions 15 a and 15 b are formed in each of the NMOS region and PMOS region through an ion implantation process. However, the following limitations may occur due to the structure of the symmetric semiconductor device.
[0006] First, the symmetric LDD structure, where source and drain terminals adjacent to opposed sides of the gates have the same size, may cause characteristic sub-threshold deterioration, and due to this, the drive current becomes lower in a saturation state.
[0007] Second, in an inversion mode (where sub-threshold current[s] occur), an LDD region of the source terminal may adversely affect the swing characteristic[s] of the device, and the parasitic capacitance of an overlapping portion of the gate and the LDD region may slow down an operational speed of the device. For example, in a flip-flop circuit that includes symmetric semiconductor devices, due the influence of the drive current and the capacitance(s), an edge portion of a swing characteristic graph may not have a vertical structure, but rather, may have a parabolic structure. Additionally, the propagation delay time may increase. Since the propagation delay time is proportional to the capacitance and is inversely proportional to the drive current of each MOS region, there may be a limitation in reducing the propagation delay time in a circuit including the symmetric semiconductor device(s).
[0008] Third, the junction depth of the active region is a very important factor for controlling the line width of the device and the effective channel length of a gate electrode. Therefore, the junction depth may be adjusted using In/Sb (e.g., heavy) ion implantation and Laser Spike Anneal (LSA) processes.
[0009] However, even if the junction depth is adjusted through the above techniques, the Short Channel Effect (SCE) and Reverse Short Channel Effects (RSCE) such as Gate Induced Drain Leakage (GIDL) and Drain Induced Barrier Lowering (DIBL) may occur.
[0010] Additionally, since the drive voltage is relatively high in comparison to the size of a highly-integrated semiconductor device, an injected electron may intensely accelerate in or near a source region due to the potential gradient state of the drain. Also, Hot Carrier Instability (HCI) phenomena may occur. Therefore, it becomes very difficult to control the threshold voltage of a symmetric semiconductor device.
SUMMARY
[0011] Embodiments of the present invention provide a semiconductor device having an asymmetric source/drain structure with an LDD region. Therefore, provided are a semiconductor device capable of preventing deterioration of sub-threshold characteristics and reduction(s) in drive current in a saturation state, and method(s) of manufacturing the same.
[0012] Embodiments of the invention also provide a semiconductor device with a structure that suppresses or prevents the deterioration of a swing characteristic of a device and the occurrence of a parasitic capacitance in the overlap between a gate and an LDD region in an inversion mode where a sub-threshold current occurs, and a method of manufacturing the same.
[0013] Embodiments of the invention also provide a semiconductor device capable of minimizing the Short Channel Effect (SCE), the Reverse Short Channel Effect (RSCE), and Hot Carrier Instability (HCI), and capable of controlling a threshold voltage without difficulties, and a method of manufacturing the same.
[0014] In one aspect, a semiconductor device may comprise a gate electrode on a semiconductor substrate having a device isolation region; a first drain spacer on one side of the gate electrode; a second drain spacer next to the first drain spacer; a first source spacer on an opposite side of the gate electrode and on a portion of the semiconductor substrate adjacent to a source region; a second source spacer on the side and top of the first source spacer; and an LDD on the side of the first drain spacer and in the semiconductor substrate below the first and second source spacers, wherein the LDD region below the first source spacer is thinner than the LDD region the first drain spacer.
[0015] In another aspect, a method of manufacturing a semiconductor device may comprise forming a gate electrode on a semiconductor substrate having a device isolation region; forming a first drain spacer on one side of the gate electrode and forming a first spacer layer on an opposite side of the gate electrode and on the semiconductor substrate where a source region is to be formed; forming an asymmetric Lightly Doped Drain (LDD) region by implanting ions on the exposed semiconductor substrate next to the first drain spacer and implanting ions that penetrate the first spacer layer where the source region is to be formed; forming a second spacer next to the first drain spacer, partially removing the first spacer layer of the semiconductor substrate where the source region is to be formed, to allow a remaining portion of the first spacer layer to form a first source spacer, and forming a second source spacer on a side and top surface of the first source spacer.
[0016] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIGS. 1 to 3 are views illustrating an exemplary manufacturing process for a symmetric semiconductor device.
[0018] FIG. 4 is a cross-sectional view illustrating a form of an exemplary semiconductor device after a polysilicon layer is formed according to an embodiment.
[0019] FIG. 5 is a cross-sectional view illustrating a form of an exemplary semiconductor device after a hard mask layer is formed according to another embodiment.
[0020] FIG. 6 is a cross-sectional view illustrating an exemplary semiconductor device after a second photoresist pattern is formed according to a further embodiment.
[0021] FIG. 7 is a cross-sectional view illustrating an exemplary semiconductor device after NMOS LDD regions and PMOS regions are formed according to yet another embodiment.
[0022] FIG. 8 is a cross-sectional view illustrating an exemplary semiconductor device after a second spacer layer is formed according to various embodiments.
[0023] FIG. 9 is a cross-sectional view illustrating an exemplary semiconductor device after NMOS spacers and PMOS spacers are completed.
[0024] FIG. 10 is a graph when a drive current characteristic of an exemplary semiconductor device is measured according to one or more embodiments.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0025] A semiconductor device and a method of manufacturing the same according to various embodiments will be described in detail with reference to the accompanying drawings.
[0026] Hereinafter, during the description about one or more exemplary embodiments, detailed descriptions related to well-known functions or configurations will be omitted in order not to obscure the subject matter of the present invention. Thus, core components related to the technical scope of the present invention will be discussed in detail below.
[0027] In the description of such embodiments, it will be understood that when a layer (or film), region, pattern or structure is referred to as being ‘on’ or ‘under’ another layer (or film), region, pad or pattern, the terminology of ‘on’ and ‘under’ includes both the meanings of ‘directly’ and ‘indirectly’. Further, the reference about ‘on’ and ‘under’ each layer will be made on the basis of drawings.
[0028] FIG. 4 is a cross-sectional view illustrating a form of an exemplary semiconductor device precursor after a polysilicon layer 130 is formed according to various embodiment(s).
[0029] A trench is formed in the semiconductor substrate 100 of a material such as silicon, and an insulation layer is filled in the trench to form a device isolation region 110 . The trench may be formed by photolithographic patterning and etching, and the device isolation region 110 may comprise a shallow trench isolation (STI) structure, including one or more silicon oxides (e.g., a thin silicon dioxide layer on the trench surface, formed by wet or dry thermal oxidation, and a bulk silicon dioxide layer filling the trench, formed by plasma-assisted CVD [e.g., high density plasma (HDP) CVD] and annealing to densify the bulk silicon dioxide material). Based on the device isolation region 110 , one side of the semiconductor substrate 100 comprises a region where an N-type Metal Oxide Semiconductor (NMOS) device is to be formed, and the other side of the semiconductor substrate 100 comprises a region where a P-type MOS (PMOS) device is to be formed.
[0030] Well regions (not shown) for each type of MOS device are respectively formed in the NMOS region and the PMOS region of the semiconductor substrate 100 , and then an insulation layer 120 and a polysilicon layer 130 are formed on the semiconductor substrate 100 . The insulation layer 120 may comprise or consist essentially of SiO 2 (formed, e.g., by wet or dry thermal oxidation) or SiON (silicon oxynitride, formed by thermal oxidation and nitridization or by plasma CVD). The polysilicon layer 130 may be formed by plasma-assisted CVD from a silicon precursor such as silane (SiH 4 ). Next, ions of As and Sb are implanted in the polysilicon layer 130 in the NMOS region, and ions of B and In are implanted in the polysilicon layer 130 in the PMOS region in order to dope the polysilicon layer 130 .
[0031] FIG. 5 is a cross-sectional view illustrating an exemplary precursor for an exemplary semiconductor device after a hard mask layer 140 is formed according to various embodiment(s).
[0032] Once the polysilicon layer 130 is formed, the hard mask layer 140 is formed thereon. The hard mask layer 140 , which may comprise one or more layers of a silicon oxide (e.g., silicon dioxide) and/or silicon nitride, prevents the polysilicon layer 130 constituting a gate electrode from being etched when an etching process is performed later. The hard mask layer(s) 140 may be formed by CVD (e.g., plasma assisted CVD, as described herein).
[0033] FIG. 6 is a side-sectional view illustrating an exemplary precursor for an exemplary semiconductor device after a second photoresist pattern 155 is formed according to various embodiment(s).
[0034] A first photoresist pattern (not shown) is formed on the hard mask layer 140 to define gate electrodes in the NMOS region and the PMOS region. Through an etching process, the insulation layer 120 , the polysilicon layer 130 , and the hard mask layer 140 are etched in reverse sequence. The insulation layer 120 may constitute an NMOS gate insulation layer 120 a and a PMOS gate insulation layer 120 b after etching. Additionally, the polysilicon layer 130 may constitute an NMOS gate electrode 130 a and a PMOS gate electrode 130 b after etching. Additionally, the hard mask layer 140 may constitute an NMOS hard mask 140 a and a PMOS hard mask 140 b after etching.
[0035] Later, the first photoresist pattern is removed, and a first spacer layer 150 is deposited on the semiconductor substrate 100 including the gate insulation layers 120 a and 120 b , the gate electrodes 130 a and 130 b , and the hard masks 140 a and 140 b . The first spacer layer 150 may comprise SiN and may be deposited using Low Pressure Chemical Vapor Deposition (LP-CVD).
[0036] Once the first spacer layer 150 is deposited, a second photoresist pattern 155 is formed to expose a portion A where an NMOS drain region is to be formed and a portion B where a PMOS drain region is to be formed.
[0037] FIG. 7 is a cross-sectional view illustrating an exemplary precursor for an exemplary semiconductor device after NMOS LDD regions 160 a and 160 b and PMOS regions 160 c and 160 d are formed according to various embodiment(s).
[0038] From the structure shown in FIG. 6 , an etching process is performed using the second photoresist pattern 155 as an etching mask. At this point, the etching process may comprise a dry (e.g., anisotropic) etching technique. Therefore, a portion of the first spacer layer 150 on the hard masks 140 a and 140 b , the first spacer layer 150 on the portions A and B where a drain region is to be formed, and the first spacer layer 150 at the NMOS side of the device isolation region 110 are removed.
[0039] Additionally, the first spacer layer 150 remains on the drain region (or a portion thereof) of the NMOS region and the sidewalls at the drain region of the NMOS gate insulation layer 120 a , the NMOS gate electrode 130 a , and the NMOS hard mask 140 a , such that an NMOS first drain spacer 150 a is formed. Additionally, the first spacer layer 150 remains on the drain region (or a portion thereof) of the PMOS region and the sidewalls at the drain region of the PMOS gate insulation 120 b , the PMOS gate electrode 130 b , and the PMOS hard mask 140 b , such that a PMOS first drain spacer 150 b is formed. At this point, the top portions of the NMOS first drain spacer 150 a and the PMOS first drain spacer 150 b may be partially etched to have a rounded form.
[0040] Next, the second photoresist pattern 155 is removed and one or more ion implantation processes are performed. For example, a photoresist mask (not shown) may be formed by photolithography over the NMOS region before implanting ions into the PMOS region, and a separate photoresist mask (not shown) may be formed by photolithography over the PMOS region before implanting ions into the NMOS region. Therefore, an LDD region 160 a of the NMOS source region, an LDD region 160 b of the NMOS drain region, an LDD region 160 c of the PMOS source region, and an LDD region 160 d of the PMOS drain region are formed.
[0041] When the ion implantation process is performed, the first spacer layer 150 of the NMOS source region and the first spacer layer 150 of the PMOS source region, which are not etched as a result of the second photoresist pattern 155 , partially prevent ions from being implanted. Accordingly, the LDD region 160 a of the NMOS source region and the LDD region 160 c of the PMOS source region may have (or be formed with) a shallower depth than the LDD region 160 b of the NMOS drain region and the LDD region 160 d of the PMOS drain region. That is, according to the exemplary process, an asymmetric LDD structure can be formed.
[0042] Additionally, even if the LDD regions 160 a , 160 b , 160 c , and 160 d may diffuse into or under the gate electrodes 130 a and 130 b , because of the first drain spacers 150 a and 150 b and the first spacer layer 150 remaining on the source region, the diffusion region is restricted such that the overlap phenomenon of the LDD regions 160 a , 160 b , 160 c , and 160 d and the gate electrodes 130 a and 130 b can be reduced, minimized or prevented.
[0043] The NMOS LDD regions 160 a and 160 b may be formed by implanting ions such as As and/or Sb. At this point, a pocket implantation process may be further performed using BF 2 ions.
[0044] Additionally, the PMOS LDD regions 160 c and 160 d may be formed by implanting ions such as B and/or In. At this point, a halo implantation process may be further performed using ions such as As and/or Sb.
[0045] FIG. 8 is a cross-sectional view illustrating an exemplary precursor for an exemplary semiconductor device after a second spacer layer 170 is formed according to various embodiments.
[0046] Next, a second spacer layer 170 is formed on the semiconductor substrate 100 including the remaining first spacer layer 150 , the hard masks 140 a and 140 b , the NMOS first drain spacer 150 a , the PMOS first drain spacer 150 b , the LDD region 160 b of the NMOS drain region, the LDD region 160 d of the PMOS drain region, and a portion of the device isolation region 110 . The second spacer layer 170 may comprise SiN and/or SiO 2 , and may be deposited by CVD (which may be plasma assisted).
[0047] Although the second spacer layer 170 is deposited with the same thickness (e.g., conformally), since an asymmetric structure of the reaming first spacer layer 150 , NMOS first drain spacer 150 a , and PMOS first drain spacer 150 b is reflected, the second spacer layer 170 has an asymmetric structure with respect to the source region and the drain region of a given NMOS or PMOS device.
[0048] FIG. 9 is a cross-sectional view illustrating an exemplary precursor for an exemplary semiconductor device after NMOS spacers 150 a , 150 c , 170 a , and 170 b and PMOS spacers 150 b , 150 d , 170 c , and 170 d are completed.
[0049] Next, an etching process without a photoresist pattern (for example, a blanket etching process) is performed to complete a spacer structure according to one or more embodiments. Through the blanket etching process, the second spacer layer 170 and the remaining first spacer layer 150 on the NMOS hard mask 140 a and the PMOS hard mask 140 b are partially removed. Additionally, the first spacer layer 150 remaining on the sidewalls at the source region of the NMOS gate insulation layer 120 a , the NMOS gate electrode 130 a , the NMOS hard mask 140 a , and the second spacer layer 170 are partially etched to form NMOS first and second source spacers 150 c and 170 a , respectively. Additionally, the second spacer layer 170 next to the NMOS first drain spacer 150 a is etched at the same time to form an NMOS second drain spacer 170 b . In the same manner, the first spacer layer 150 remaining on the sidewalls at the source region of the PMOS gate insulation layer 120 b , the PMOS gate electrode 130 b , and the PMOS hard mask 140 b , and the second spacer layer 170 are partially etched to form PMOS first and second source spacers 150 d and 170 c , respectively. That is, the second source spacers 170 a and 170 c are formed on the top and side of the first source spacers 150 c and 150 d , respectively. Additionally, the second spacer layer 170 next to the PMOS first drain spacer 150 b is etched at the same time to form a PMOS second drain spacer 170 d . The first spacer layer 150 and the second spacer layer 170 remaining on other than the above portions are removed.
[0050] The structure of the first spacers 150 a , 150 b , 150 c , and 150 d , and the second spacers 170 a , 170 b , 170 c , and 170 d of the NMOS and PMOS regions utilizes etching characteristics of a dry (e.g., anisotropic) etching process.
[0051] Next, using the first spacers 150 a , 150 b , 150 c , and 150 d , the second spacers 170 a , 170 b , 170 c , and 170 d , the hard masks 140 a and 140 b , and the device isolation region 110 as an ion implantation mask, one or more ion implantation processes are performed to form source regions 180 a and 180 c and drain regions 180 b and 180 d in the NMOS region and the PMOS region, respectively. For example, a photoresist mask (not shown) may be formed by photolithography over the NMOS region before implanting ions into the PMOS region, and a separate photoresist mask (not shown) may be formed by photolithography over the PMOS region before implanting ions into the NMOS region.
[0052] Once the source regions 180 a and 180 c and the drain regions 180 b and 180 d are formed, a thermal treatment process such as Laser Spike Anneal (LSA) and/or Rapid Thermal Anneal (RTA) is performed to activate the source regions 180 a and 180 c and the drain regions 180 b and 180 d.
[0053] The semiconductor device and the method of manufacturing the same according to the embodiments use two regions of the PMOS region and the NMOS region as one example, but can be apparently applied to a semiconductor region of more than two regions or a single semiconductor region.
[0054] FIG. 10 is a graph of a drive current characteristic of a semiconductor device, measured according to one or more embodiments.
[0055] In the graph of FIG. 10 , the x-axis represents a drive voltage V, and the y-axis represents a drive current (in μA/μm). Additionally, measurement line 11 represents a current characteristic of the semiconductor device according to an exemplary embodiment of the invention, and measurement line 12 represents a current characteristic of a related art symmetric semiconductor device. Referring to FIG. 10 , if the same drive voltage is applied, it is confirmed that the drive current of a semiconductor device according to the present invention is increased more than the symmetric semiconductor.
[0056] According to various embodiments of the invention, the following effects can be achieved.
[0057] First, through an asymmetric LDD structure and an asymmetric double spacer structure, one or more sub-threshold characteristics of a semiconductor device can be maximized, and the flow of a drive current can be improved in an inversion mode.
[0058] Second, through the double spacer structure, the profile of an underlying LDD region can be finely controlled. Additionally, a self-aligned asymmetric LDD structure can reduce, suppress or minimize an overlap phenomenon between the gate and the LDD region. Accordingly, a swing characteristic of the semiconductor device can be improved, and a propagation delay time can be minimized.
[0059] Third, since characteristics of GIDL and DIBL can be improved and a propagation delay time of the device can be minimized, the operational speed of the semiconductor device can be improved and operational reliability can be increased.
[0060] Any reference in this specification to “one embodiment”, “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments.
[0061] Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
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Provided are a semiconductor device and a method of manufacturing the same. The semiconductor device comprises a gate electrode on a semiconductor substrate having a device isolation region, a first drain spacer on one side of the gate electrode, a second drain spacer next to the first drain spacer, a first source spacer on an opposite side of the gate electrode and a portion of the semiconductor substrate where a source region is to be formed, a second source spacer on side and top surfaces of the first source spacer, and LDDs adjacent to the first drain spacer and below the first source spacers, wherein the LDD below the first source spacer is thinner than the LDD adjacent to the first drain spacer.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates broadly to telecommunications, the Synchronous Optical Network (SONET) and the Synchronous Digital Hierarchy (SDH). More particularly, this invention relates to buffer management during virtual concatenation (VCAT) and link capacity adjustment scheme (LCAS).
[0003] 2. State of the Art
[0004] The Synchronous Optical Network (SONET) or the Synchronous Digital Hierarchy (SDH), as it is known in Europe, is a common telecommunications transport scheme which is designed to accommodate both DS-1 (T1) and E1 traffic as well as multiples (DS-3 and E-3) thereof. A DS-1 signal consists of up to twenty-four time division multiplexed DS-0 signals plus an overhead bit. Each DS-0 signal is a 64 kb/s signal and is the smallest allocation of bandwidth in the digital network, i.e. sufficient for a single telephone connection. An E1 signal consists of up to thirty-two time division multiplexed DS-0 signals with at least one of the DS-0s carrying overhead information.
[0005] Developed in the early 1980s, SONET has a base (STS-1) rate of 51.84 Mbit/sec in North America. The STS-1 signal can accommodate 28 DS-1 signals or 21 E1 signals or a combination of both. The basic STS-1 signal has a frame length of 125 microseconds (8,000 frames per second) and is organized as a frame of 810 octets (9 rows by 90 byte-wide columns). It will be appreciated that 8,000 frames*810 octets per frame*8 bits per octet=51.84 Mbit/sec. The frame includes the synchronous payload envelope (SPE) or virtual container (VC) as it is known in Europe, as well as transport overhead. Transport overhead is contained in the first three columns (27 bytes) and the SPE/VC occupies the remaining 87 columns.
[0006] In Europe, the base (STM-1) rate is 155.520 Mbit/sec, equivalent to the North American STS-3 rate (3*51.84=155.520). The STS-3 (STM-1) signals can accommodate 3 DS-3 signals or 63 E1 signals or 84 DS-1 signals, or a combination of them. The STS-12 (STM4) signals are 622.080 Mbps and can accommodate 12 DS-3 signals, etc. The STS-48 signals are 2,488.320 Mbps and can accommodate 48 DS-3 signals, etc. The highest defined STS signal, the STS-768, is nearly 40 Gbps (gigabits per second). The abbreviation STS stands for Synchronous Transport Signal and the abbreviation STM stands for Synchronous Transport Module. STS-n signals are also referred to as Optical Carrier (OC-n) signals when transported optically rather than electrically.
[0007] To facilitate the transport of lower-rate digital signals, the SONET standard uses sub-STS payload mappings, referred to as Virtual Tributary (VT) structures. (The ITU calls these structures Tributary Units or TUs.) This mapping divides the SPE (VC) frame into seven equal-sized sub-frames or VT (TU) groups with twelve columns of nine rows (108 bytes) in each. Four virtual tributary sizes are defined as follows.
[0008] VT1.5 has a data transmission rate of 1.728 Mb/s and accommodates a DS1 signal with overhead. The VT1.5 tributary occupies three columns of nine rows, i.e. 27 bytes. Thus, each VT Group can accommodate four VT1.5 tributaries.
[0009] VT2 has a data transmission rate of 2.304 Mb/s and accommodates a CEPT-1 (E1) signal with overhead. The VT2 tributary occupies four columns of nine rows, i.e. 36 bytes. Thus, each VT Group can accommodate three VT2 tributaries.
[0010] VT3 has a data transmission rate of 3.456 Mb/s) and accommodates a DS1 C signal with overhead. The VT3 tributary occupies six columns of nine rows, i.e. 54 bytes. Thus, each VT Group can accommodate two VT3 tributaries.
[0011] VT6 has a data transmission rate of 6.912 Mb/s and accommodates a DS2 signal with overhead. The VT6 tributary occupies twelve columns of nine rows, i.e. 108 bytes. Thus, each VT Group can accommodate one VT6 tributary.
[0012] As those skilled in the art will appreciate, the original SONET/SDH scheme as well as the VT mapping schemes were designed to carry known and potentially foreseeable TDM (time division multiplexed) signals. In the early 1980s these TDM signals were essentially multiplexed telephone lines, each having the (now considered) relatively small bandwidth of 56-64 kbps. At that time, there was no real standard for data communication. There were many different schemes for local area networking and the wide area network which eventually became known as the Internet was based on a “56 kbps backbone”. Since then, Ethernet has become the standard for local area networking. Today Ethernet is available in four bandwidths: the original 10 Mbps system, 100 Mbps Fast Ethernet (IEEE 802.3u), 1,000 Mbps Gigabit Ethernet (IEEE 802.3z/802.3ab), and 10 Gigabit Ethernet (IEEE 802.3ae).
[0013] In recent years it has been recognized that SONET/SDH is the most practical way to link high speed Ethernet networks over a wide area. Unfortunately, the various Ethernet transmission rates (10 Mbps, 100 Mbps, 1,000 Mbps, and 10,000 Mbps) do not map well into the SONET/SDH frame. For example, the original 10 Mbps Ethernet signal is too large for a VT-6 tributary (6.912 Mbps) but too small for an entire STS-1 (51.84 Mbps) path. In other words, under the existing SONET/SDH schemes, in order to transport a 10 Mbps Ethernet signal, an entire STS-1 path must be used, thereby wasting a significant amount of bandwidth. Similar results occur when attempting to map the faster Ethernet signals into STS signals.
[0014] In order to provide a scheme for efficiently mapping Ethernet signals (as well as other signals such as Fiber Channel and ESCON) into a SONET/SDH frame, the Virtual Concatenation (VCAT) Protocol was created and has been endorsed by the ITU as the G.707 standard (ITUT-T Rec. G.707/Y.1322 (December 2003)) which is hereby incorporated by reference herein in its entirety. Similar to inverse multiplexing, Virtual Concatenation combines multiple links (members) into one Virtual Concatenation Group (VCG), enabling the carrier to optimize the SDH/SONET links for Ethernet traffic. For example, using virtual concatenation, five VT-2 (2 Mbps) links can be combined to carry a 10 Mbps Ethernet signal, resulting in full utilization of allotted bandwidth. Two STS-1 (51 Mbps) links can be combined to carry a 100 Mbps Ethernet signal, etc. Virtual Concatenation uses SONET/SDH overhead bytes (four of the sixteen “H4” bytes) to indicate two numbers: the multiframe indicator (MFI) and the sequence number (SQ).
[0015] Part of the emerging Virtual Concatenation Protocol includes methods for dynamically scaling the available bandwidth in a SONET/SDH signal. These methods are known as the Link Capacity Adjustment Scheme or LCAS. LCAS is a powerful network management tool because customer bandwidth requirements change over time. One simple example is a network user who, during business hours, needs only enough bandwidth to support electronic mail and worldwide web access. During non-working hours, however, the same network user may wish to conduct relatively large data transfers from one location to another to backup daily transactions, for example. It would be desirable to alter the user's available bandwidth as needed. LCAS provides a means to do this without disturbing other traffic on the link. LCAS has been endorsed by the ITU as the G.7042 standard (ITU-T Rec. G.7042/Y.1305 (February 2004)) which is hereby incorporated by reference herein in its entirety.
[0016] While Virtual Concatenation is a simple labeling protocol, LCAS requires a two-way handshake (using seven of the sixteen H4 bytes for high order, STS-1, and seventeen of the thirty-two K4 bits for low order, VT1.5). Status messages are continually exchanged and actions are taken based on the content of the messages. For example, to provide high order (STS-1) virtual concatenation, each STS-1 signal carries one of six LCAS control commands which are described as follows:
[0017] “Fixed”—LCAS not supported on this STS-1 (“Fixed” is actually inferred rather than sent as a command. It is inferred when all of the LCAS fields other than MFI and SEQ are zero.);
[0018] “Add”—Expresses an intention to add this STS-1 to a VCG, thereby increasing the bandwidth of an existing VCG or creating a new VCG (Bandwidth is increased upon acknowledgement from the sink.);
[0019] “Norm”—This STS-1 is in use and is not the last member of a VCG;
[0020] “EOS”—This STS-1 is in use and is the last payload carrying STS-1 of this VCG, i.e. the payload carrying STS-1 with the highest SQ number;
[0021] “Idle”—This STS-1 is not in use in a VCG or is about to be removed from a VCG;
[0022] “Do not use”—This STS-1 is supposed to be part of a VCG, but does not transport payload due to a broken link reported by the destination. Members of a VCG which do not carry payload are termed “inactive” whereas members which carry payload are termed “active”.
[0023] Although SONET is said to be synchronous, it is actually plesiochronous. The clocks at different switches in the network actually differ in rate and also drift somewhat. Measures are provided to account for these clock differences which are seen as “justifications” in the overhead of the SONET signal. These justifications instruct the next switch in the path to add or remove “stuff bytes”.
[0024] Due to the nature of the SONET network, it is possible for individual members of a VCG to traverse different network paths between their origin and destination. Because of this, members will arrive at their destination out of order and with different delays. This situation is generally referred to as “skewing”. In order to reassemble the members of a VCG in proper order without undue delay and without losing any members, the arriving members must be buffered and deskewed. Deskewing uses the multiframe indicator (MFI) as a time stamp to align all of the VCG members. Challenges to the deskewing process include: achieving minimal latency, accounting for justifications, adjusting for increases and decreases in member delay, dealing with the presence of inactive VCG members, and managing start-up and disruptions.
[0025] In its simplest form, deskewing involves placing members of a VCG in a buffer until the member with the most delay is received, then reading the members out of the buffer in the proper order. If the buffer is read at a fixed rate dictated by the slowest member, the other members still stay buffered incurring a latency dictated not by their differential delay but by the differential delay with respect to the slowest member. If a member with the largest delay is removed from a group, the other members of the group are still subject to the long delay and buffer space is wasted. As a result, in these systems the system delay is effectively the history of the member of the VCG having the longest delay. This is a likely situation in the case of bandwidth adjustments using the LCAS protocol or due to configuration changes.
SUMMARY OF THE INVENTION
[0026] It is therefore an object of the invention to provide a method for deskewing a SONET signal containing a VCG.
[0027] It is another object of the invention to provide a method for deskewing a SONET signal containing a VCG which achieves minimal latency.
[0028] It is a further object of the invention to provide a method for deskewing a SONET signal containing a VCG which accounts for justifications.
[0029] It is also an object of the invention to provide a method for deskewing a SONET signal containing a VCG which adjusts for changes in the path delay of VCG members.
[0030] It is an additional object of the invention to provide a method for deskewing a SONET signal containing a VCG which accounts for inactive VCG members.
[0031] It is still another object of the invention to provide a method for deskewing a SONET signal containing a VCG which manages start-ups and disruptions.
[0032] In accord with these objects, which will be discussed in detail below, write logic and read logic are coupled to SDRAM and a frame status table. Individual arriving VCG members are individually written into SDRAM by the write logic and an entry (based on the MFI and SQ) in the frame status table is maintained by the write logic for each member. The frame status is one of: started, finished, not started, and abandoned. The read logic scans the frame status table to identify the earliest frame number for which data of all members is available in SDRAM. Based on the frame status and the difference between the read and write address pointers, the read logic maintains a state table entry for each VCG member. Member state is one of: MFI wait offset wait due to slower member, MFI wait offset due to no read, MFI wait offset advance, and MFI advance. Based on the member states, the read logic computes a state for each VCG. The VCG states are initialized to the state of the first member and are updated as additional members of the VCG are encountered.
[0033] According to the preferred embodiment, the read logic is provided in two parts separated by a temporary buffer. The first part of the read logic performs the functions described above and writes chunk data into the temporary buffer. The second part of the read logic reads byte data from the temporary buffer according to a selectable leak rate (fast or slow) while maintaining approximately 15 microseconds of data in SDRAM and the temporary buffers. The second part of the read logic receives specific SONET signaling (clock, SPE, H3, and C1) and utilizes a bus limited to that signaling and the data (called the “combus”) to transport bytes to a demapper. In the case of a fast leak, valid data is read out of the temporary buffer when the SPE is high and the leaked data is sent over the combus during the entire TOH part of the frame except for the C1 byte so that the demapper can identify the framing and hence the slots. In the slow leak mode, leaked data is read and sent in every H3 byte. The second part of the read logic provides feedback to the first part regarding the availability of space in the temporary buffer.
[0034] Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a simplified block diagram of an apparatus according to the invention;
[0036] FIG. 2 is a simplified flowchart illustrating the methods of the invention;
[0037] FIG. 3 is a simplified flowchart illustrating the processing of frame status and read and write pointer offsets to obtain member states;
[0038] FIG. 4 is a simplified flowchart illustrating the processing of member states to obtain VCG state; and
[0039] FIG. 5 is a simplified flow chart illustrating the operation of the second part of the read logic.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0040] Turning now to FIG. 1 , a deskewing apparatus 10 according to the invention includes write logic 12 , an SDRAM buffer 13 , a frame status table 14 , read logic 15 , 18 , a register 16 for storing member and VCG states and a temporary buffer 17 . The write logic 12 receives skewed data 11 (VCG members with different delays and not necessarily in proper order). When the write logic 12 begins to receive a frame, it is written to the buffer 13 and, after a complete word is formed, the status of the frame is entered into the table 14 . According to the presently preferred embodiment, the buffer 13 and the table 14 are sized to accommodate five hundred twelve frames of data and frame status indications respectively. The frame status values are listed and explained in Table 1.
TABLE 1 Frame Status Description Not Started This is the default status indicating that no payload for (FS_NS) this MFI number is available in the buffer. In addition, if the MFI of a member jumps forward, the write logic sets the status to Not Started for intervening MFI numbers. Started This indicates that some payload for this MFI number (FS_S) has been written to the buffer but the frame is not complete. Finished This indicates that this frame is completely written to the (FS_F) buffer. Abandoned This indicates that the frame could not be completed. (FS_A)
[0041] The first part of the read logic 15 uses the frame status and the offset between the buffer write pointer and read pointer to determine when and what to read from the buffer 13 and store in the buffer 17 . The first part of the read logic 15 outputs deskewed data (VCG members in proper order, one after the other, with no delay between members) to the temporary buffer 17 .
[0042] The second part of the read logic 18 receives combus signaling 19 (including clock, SPE, H3, and C1) and utilizes the combus 20 to transport bytes to a demapper 21 . In the case of a fast leak, valid data is read out of the temporary buffer 17 when the SPE signal is high and the leaked data is sent over the combus 20 during the entire TOH part of the frame except for the C1 byte so that the demapper can identify the framing and hence the slots. In the slow leak mode, leaked data is read and sent in every H3 byte. The second part of the read logic 18 also provides feedback to the first part 15 regarding the availability of space in the temporary buffer 17 . The leak mode is normally set by the user and defaults to fast leak mode. However, the leak mode can be automatically adjusted by monitoring the pointer offset and causing a shift from slow leak mode to fast leak mode for a one time read if the pointer offset exceeds a threshold.
[0043] Those skilled in the art will appreciate that the MFI and SEQ numbers are distributed over sixteen frames. According to the presently preferred embodiment, the skewed data 11 is from an OC- 48 signal and the concatenation is high order, i.e. up to 48 members. Therefore, 48×16 frames must be received before all of the MFI and SEQ numbers are known. (It will be appreciated, however, that the implementation also applies to a TU3.) The frame status table 14 is therefore preferably arranged with 48 columns and 512 rows. As the table 14 is filled, data is discarded until the MFI pattern is recognized. After the pattern is recognized, data is written to the SDRAM 13 using the MFI to address the data. Each MFI is associated with one frame which is 783 bytes (the payload of an STS-1, but it could also be implemented for the payload of a TU3). The frame status table 14 of this size can accommodate a maximum differential delay of 64 ms between members. This delay is the maximum differential delay experienced in a terrestrial network. FIG. 2 illustrates the basic sequence of processes performed by the read logic 16 . FIGS. 3 and 4 illustrate the processing in more detail.
[0044] Turning now to FIG. 2 . and with reference to FIG. 1 , starting at 22 , the read logic 15 reads the frame status table 14 at 24 . For each entry in the frame status table, the read logic determines at 26 a member state which is stored in the register 16 . The member state values are listed and explained in Table 2.
TABLE 2 Member State Description MFI wait offset wait If there is no data available in the frame being due to slower member addressed by the read logic and for any of the (MWOWSL) members of the VCG, the write address pointer is behind the read address, then wait for the write pointer to catch up. MFI advance (MA) Advance read MFI address of frame status table by one. This is done when the frame is read completely or frame status is not started and write MFI is ahead of read MFI or FS_A is encountered for any members of the VCG. MFI wait offset wait Do not change the read MFI address of the due to no read frame status table and read offset of SDRAM (MWOWNr) for current read frame. The no read may be because there is not enough data to begin reading. MFI wait offset Increment the read offset of the current read advance (MWOA) frame and read the frame from the buffer.
[0045] After the entire frame status table for one MFI (for all the members of a VCG) has been processed at 26 , the member states are read back at 28 and processed one by one at 30 to determine the VCG states which are also stored in the register 16 . The VCG state values are determined from member state values. After all of the member states have been processed at 30 , the VCG states are read back at 32 and processed at 34 . The processing of VCG states consists of determining whether it is MWOA. At 36 the action taken is that described in Table 2 depending on the member state.
[0046] Turning now to FIG. 3 , the read logic 15 reads the frame status table and generates a VCG member state for each entry in the table based on the table entry and the read and write pointer offsets. Starting at 40 , the table entry is read and if it is abandoned (FS_A) as shown at 42 , the member state is set to MA (MFI advance) as shown at 44 .
[0047] If the frame status table entry is started (FS_S) as shown at 46 , the difference between the current write pointer offset (CWOFF) and the current read pointer offset (CROFF) is calculated and a determination is made as to whether it exceeds a threshold (TH, e.g. 64 Bytes which equals 15 microseconds of a SONET stream) at 48 . If the difference is greater than the threshold, an external control 50 chooses whether to set the member state at 52 to MWOWNr (wait due to no read) or MWOA (wait offset advance). The external control is a flow control signal from an on-chip internal FIFO through which packets pass. If that FIFO should overflow due to a data burst, the flow control signal can force the state to MWOWNr. If the FIFO is not overflowing, the state defaults to MWOA. If the difference between the pointer offsets is less than or equal to the threshold as determined at 48 , the member state is set to MWOWNr (wait due to no read).
[0048] If the frame status table entry is finished (FS_F) as shown at 56 , it is determined at 58 whether the current read pointer offset (CROFF) is equal to Last_WD as indicated by the read pointer offset. If it is not, external control 60 determines whether to set the member state at 62 to MWOWNr (wait due to no read) or MWOA (wait offset advance) The external control is a flow control signal from an on-chip internal FIFO through which packets pass. If that FIFO should overflow due to a data burst, the flow control signal can force the state to MWOWNr. If the FIFO is not overflowing, the state defaults to MWOA. If it is equal as determined at 58 , the member state is set to MA (MFI advance) as shown at 64 .
[0049] If the frame status table entry is not started (FS_NS) as shown at 66 , it is determined at 68 whether the current write MFI is less than or equal to the current read MFI. If it is, the member state is set at 70 to MWOWSL (wait due to slow member). If it is not, the member state is set at 72 to MA (MFI advance).
[0050] FIG. 4 illustrates the functions performed by the read logic 15 in setting member states. Turning now to FIG. 4 , starting at 74 , member state is examined, then it is determined at 76 whether the member is the first member of a VCG. If it is, the member's state is considered to be the VCG state at 78 . If the member is not the first member of a VCG, it is determined at 80 whether the member state is a higher priority than the current VCG state. If it is, the VCG state is advanced at 82 . If it is not, no change is made to the VCG state at 84 . This process is repeated for all of the members of the VCG. The VCG states are reported to the control plane.
[0051] FIG. 5 illustrates how the second part of the read logic ( 18 in FIG. 1 ) reads the temporary buffer ( 17 in FIG. 1 ) based on combus signaling ( 19 in FIG. 1 ). Turning now to FIG. 5 , the read logic waits at 100 until the temporary buffer is filled with 15 microseconds of data (based on the incoming data rate, e.g. 2,488.320 Mbps.) Once the temporary buffer has filled to that threshold, it is determined at 102 whether the data is to be read at a fast leak rate or a slow leak rate. If it is a slow leak rate, the read logic waits at 104 until the SPE signal is high or the H3 byte slot appears in the combus signaling (i.e., H3 high). Whenever the SPE signal or H3 is high, the read logic reads the data from the temporary buffer at 106 and sends it to the combus ( 20 in FIG. 1 ). In the case of a fast leak rate, the read logic reads the data from the temporary buffer at 106 and sends it to the combus ( 20 in FIG. 1 ) during all timeslots except when the C1 byte slot appears in the combus signaling at 108 .
[0052] There have been described and illustrated herein methods and apparatus for deskew buffer management with VCAT and LCAS. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. For example, while the invention has been described with reference to external SDRAM, other types of internal or external memory could be used. Also, while the invention has been explained with reference to high order concatenation, it could be applied to low order. Also, while the fast leak has been described with reference to sending data during all timeslots except the C1 timeslot, it will be appreciated that a fast leak can be accomplished by sending data whenever the SPE is high and in a plurality of overhead slots of the combus (instead of just H3), provided that data is not sent during the C1 timeslot. It will therefore be appreciated by those skilled in the art that modifications could be made to the provided invention without deviating from its spirit and scope as claimed.
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Write logic and read logic are coupled to SDRAM and a frame status table. VCG members are written into SDRAM by the write logic and an entry (based on the MFI and SQ) in the frame status table is maintained by the write logic for each member. The read logic scans the frame status table to identify the earliest frame number for which data is available in SDRAM. Based on the frame status and the address pointer offset, the read logic maintains a state table entry for each VCG member and a state for each VCG. According to the preferred embodiment, the read logic is provided in two parts separated by a temporary buffer. The first part of the read logic performs the functions described above and writes chunk data into the temporary buffer. The second part of the read logic reads byte data from the temporary buffer according to a selectable leak rate.
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TECHNICAL FIELD
[0001] The present invention generally relates to flame retardant bedding articles comprising a hydroentangled flame retardant nonwoven component, and more specifically, to bedding articles, including mattresses, pillow covers and mattress pads, comprising a structurally stable, flame retardant nonwoven component, wherein said component comprises at least two layers that have a synergistic relationship so as to maintain the structural integrity of the bedding article upon burning.
BACKGROUND OF THE INVENTION
[0002] More than thirty years ago, flammability standards were instituted by the Consumer Product Safety Commission under 16 C.F.R. § 1632. These standards addressed the flammability requirements of mattresses to resist ignition upon exposure to smoldering cigarettes. However, the Code of Federal Regulations failed to address the need for mattresses to resist ignition upon exposure to small open flames, such as produced by matches, lighters, and candles.
[0003] Technological advances have proven to provide mattresses, as well as bedding constituents, with significantly better flammability protection. In light of these advancements, California Legislature has mandated that the Consumer Product Safety Commission establish a revised set of standards that will ensure mattresses and bedding pass an open flame ignition test. Known as Assembly Bill 603 (AB 603), California Legislature has further mandated that the revised set of standards go into affect Jan. 1, 2004.
[0004] Flame retardant staple fiber is known in the art. Further, flame retardant fiber has been utilized in the fabrication of nonwoven fabrics for bedding applications. Nonwoven fabrics are suitable for use in a wide variety of applications where the efficiency with which the fabrics can be manufactured provides a significant economic advantage for these fabrics versus traditional textiles. However, nonwoven fabrics have commonly been disadvantaged when fabric properties are compared, particularly in terms of surface abrasion, pilling and durability in multiple-use applications. Hydroentangled fabrics have been developed with improved properties which are a result of the entanglement of the fibers or filaments in the fabric providing improved fabric integrity. Subsequent to entanglement, fabric durability can be further enhanced by the application of binder compositions and/or by thermal stabilization of the entangled fibrous matrix.
[0005] U.S. Pat. No. 3,485,706, to Evans, hereby incorporated by reference, discloses processes for effecting hydroentanglement of nonwoven fabrics. More recently, hydroentanglement techniques have been developed which impart images or patterns to the entangled fabric by effecting hydroentanglement on three-dimensional image transfer devices. Such three-dimensional image transfer devices are disclosed in U.S. Pat. No. 5,098,764, hereby incorporated by reference, with the use of such image transfer devices being desirable for providing a fabric with enhanced physical properties as well as an aesthetically pleasing appearance.
[0006] Heretofore, nonwoven fabrics have been advantageously employed for manufacture of flame retardant fabrics, as described in U.S. Pat. No. 6,489,256, to Kent, et al., which is hereby incorporated by reference. Typically, nonwoven fabrics employed for this type of application have been entangled and integrated by needle-punching, sometimes referred to as needle-felting, which entails insertion and withdrawal of barbed needles through a fibrous web structure. While this type of processing acts to integrate the fibrous structure and lend integrity thereto, the barbed needles inevitably shear large numbers of the constituent fibers, and undesirably create perforations in the fibrous structure. Needle-punching can also be detrimental to the strength of the resultant fabric, requiring that a fabric have a relatively high basis weight in order to exhibit sufficient strength.
[0007] A need exists for a more cost effective flame retardant bedding comprising nonwoven component that is cost effective, structurally stable, soft, yet durable and suitable for various end-use applications including, but not limited to bedding components, such as mattresses, mattress pads, mattress ticking, comforters, bedspreads, quilts, coverlets, duvets, pillow covers, as well as other home uses, protective apparel applications, upholstery, and industrial end-use applications.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to flame retardant bedding articles comprising a hydroentangled flame retardant nonwoven component, and more specifically, to bedding articles comprising a structurally stable, flame retardant nonwoven component, wherein said component comprises at least two layers that have a synergistic relationship so as to maintain the structural integrity of the bedding article upon burning.
[0009] In accordance with the present invention, the bedding comprised of nonwoven component comprises at least a first and second layer. The first layer comprises a blend of lyocell fiber and modacrylic fiber. The fibrous blend of the first layer provides the layered nonwoven component with exceptional strength, in addition to a soft hand. Further, the modacrylic fiber is self-extinguishing and known to char rather than melt when burned.
[0010] Adjacent the first layer is a second layer, comprising a blend of lyocell fiber, modacrylic fiber, and para-aramid fiber. Incorporating one or more para-aramid fibers maintains the fibrous structural integrity of the fabric, as well as reduces any thermal shrinkage. The composite of fibers utilized within the flame retardant layered fabric has a synergistic relationship to provide a cost effective fabric with exceptional strength, softness, and flame retardancy, wherein upon burning, the fabric chars, yet retains its structural integrity due to the incorporation of para-aramid fiber.
[0011] The layered structure of the flame retardant nonwoven bedding article component lends to the aesthetic quality of the bedding. Para-aramid fiber typically adds to the discoloration of the fabric, imparting an undesirable yellow hue. However, the lack of para-aramid fiber in the first layer, which is positioned atop the second layer, masks the discoloration of the second layer. Optionally, the construct may comprise three or more layers, wherein the additional layers may be chosen from nonwovens, wovens, and/or support layers, such as scrims.
[0012] The first and second layers of the flame retardant nonwoven bedding component are juxtapositioned and subsequently hydroentangled to form a structurally stable composite fabric. In addition, the nonwoven fabric may be hydroentangled on a foraminous surface, including, but not limited to a three-dimensional image transfer device, embossed screen, three-dimensionally surfaced belt, or perforated drum, suitably further enhancing the aesthetic quality of the fabric for a particular end-use application.
[0013] Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a diagrammatic view of apparatus utilized in accordance with the present invention so as to manufacture the flame retardant nonwoven fabric.
DETAILED DESCRIPTION
[0015] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings, and will hereinafter be described, a presently preferred embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
[0016] The structurally stable, flame retardant, bedding component of the present invention, which is comprised of nonwoven layered fabric is cost effective, structurally stable, soft, yet durable and suitable for various end-use applications including, bedding articles, such as mattresses, mattress pads, mattress ticking, comforters, bedspreads, quilts, coverlets, duvets, pillow covers, as well as other home uses, protective apparel applications, upholstery, and industrial end-use applications.
[0017] U.S. Pat. No. 3,485,706, to Evans, hereby incorporated by reference, discloses processes for effecting hydroentanglement of nonwoven fabrics. With reference to FIG. 1 , therein is illustrated an apparatus for practicing the present method for forming a structurally stable, flame retardant nonwoven bedding component. The lyocell and modacrylic fibrous components are preferably carded and cross-lapped to form first precursor web, designated P, which is consolidated by hydraulically energy to form a nonwoven layered fabric.
[0018] In accordance with the present invention, a second precursor web may be formed, designated P′, wherein the second precursor web comprises a blend of lyocell, modacrylic, and para-aramid fibrous components. Subsequently, the second precursor web is placed in juxtaposition to the first precursor web where they are united by hydroentanglement. Optionally, the adjoined first and second precursor webs are further entangled on a foraminous surface, including, but not limited to a three-dimensional image transfer device, embossed screen, three-dimensionally surfaced belt, or perforated drum, suitably further enhancing the aesthetic quality of the fabric for a particular end-use application.
[0019] It is in the purview of the present invention, that additional flame retardant fibers be incorporated in either one or both of the precursor webs, these fibers include, but are not limited to melamine fibers, phenolic fibers, such as Kynol™ fiber from American Kynol, Inc., pre-oxidized polyacrylonitrile fibers, such as Panox® fiber, a registered trademark to R.K. Textiles Composite Fibres Limited.
[0020] FIG. 1 illustrates a hydroentangling apparatus, whereby the apparatus includes a foraminous forming surface in the form of belt 12 upon which the precursor webs P and P′ are positioned for entangling or pre-entangling by manifold 14 .
[0021] The entangling apparatus of FIG. 1 may optionally include an imaging and patterning drum 18 comprising a three-dimensional image transfer device for effecting imaging and patterning of the lightly entangled precursor web. The image transfer device includes a moveable imaging surface which moves relative to a plurality of entangling manifolds 22 which act in cooperation with three-dimensional elements defined by the imaging surface of the image transfer device to effect imaging and patterning of the fabric being formed.
[0022] In addition to the first and second layers of the flame retardant nonwoven fabric, it is also contemplated that one or more supplemental layers be added, wherein such layers may include a spunbond fabric. In general, the formation of continuous filament precursor webs involves the practice of the “spunbond” process. A spunbond process involves supplying a molten polymer, which is then extruded under pressure through a large number of orifices in a plate known as a spinneret or die. The resulting continuous filaments are quenched and drawn by any of a number of methods, such as slot draw systems, attenuator guns, or Godet rolls. The continuous filaments are collected as a loose web upon a moving foraminous surface, such as a wire mesh conveyor belt. When more than one spinneret is used in line for the purpose of forming a multi-layered fabric, the subsequent webs are collected upon the uppermost surface of the previously formed web. Further, the addition of a continuous filament fabric may include those fabrics formed from filaments having a nano-denier, as taught in U.S. Pat. No. 5,678,379 and No. 6,114,017, both incorporated herein by reference. Further still, the continuous filament fabric may be formed from an intermingling of conventional and nano-denier filaments.
[0023] It has been contemplated that the nonwoven fabric of the present invention incorporate a meltblown layer. The meltblown process is a related means to the spunbond process for forming a layer of a nonwoven fabric is the meltblown process. Again, a molten polymer is extruded under pressure through orifices in a spinneret or die. High velocity air impinges upon and entrains the filaments as they exit the die. The energy of this step is such that the formed filaments are greatly reduced in diameter and are fractured so that microfibers of finite length are produced. This differs from the spunbond process whereby the continuity of the filaments is preserved. The process to form either a single layer or a multiple-layer fabric is continuous, that is, the process steps are uninterrupted from extrusion of the filaments to form the first layer until the bonded web is wound into a roll. Methods for producing these types of fabrics are described in U.S. Pat. No. 4,041,203. Nanofiber fabrics may be utilized as well and are represented by U.S. Pat. No. 5,678,379 and No. 6,114,017, both incorporated herein by reference. The meltblown process, as well as the cross-sectional profile of the meltblown microfiber, is not a critical limitation to the practice of the present invention.
[0024] In accordance with the present invention, the structurally stable, hydroentangled, flame retardant, nonwoven bedding component may comprise a film layer. The formation of finite thickness films from thermoplastic polymers, suitable as a strong and durable carrier substrate layer, is a well-known practice. Thermoplastic polymer films can be formed by either dispersion of a quantity of molten polymer into a mold having the dimensions of the desired end product, known as a cast film, or by continuously forcing the molten polymer through a die, known as an extruded film. Extruded thermoplastic polymer films can either be formed such that the film is cooled then wound as a completed material, or dispensed directly onto a secondary substrate material to form a composite material having performance of both the substrate and the film layers.
[0025] Extruded films can be formed in accordance with the following representative direct extrusion film process. Blending and dosing storage comprising at least one hopper loader for thermoplastic polymer chip and, optionally, one for pelletized additive in thermoplastic carrier resin, feed into variable speed augers. The variable speed augers transfer predetermined amounts of polymer chip and additive pellet into a mixing hopper. The mixing hopper contains a mixing propeller to further the homogeneity of the mixture. Basic volumetric systems such as that described are a minimum requirement for accurately blending the additive into the thermoplastic polymer. The polymer chip and additive pellet blend feeds into a multi-zone extruder. Upon mixing and extrusion from the multi-zone extruder, the polymer compound is conveyed via heated polymer piping through a screen changer, wherein breaker plates having different screen meshes are employed to retain solid or semi-molten polymer chips and other macroscopic debris. The mixed polymer is then fed into a melt pump, and then to a combining block. The combining block allows for multiple film layers to be extruded, the film layers being of either the same composition or fed from different systems as described above. The combining block is connected to an extrusion die, which is positioned in an overhead orientation such that molten film extrusion is deposited at a nip between a nip roll and a cast roll.
[0026] In addition, breathable films can be used in conjunction with the disclosed continuous filament laminate. Monolithic films, as taught in patent number U.S. Pat. No. 6,191,211, and microporous films, as taught in patent number U.S. Pat. No. 6,264,864, both patents herein incorporated by reference, represent the mechanisms of forming such breathable films.
EXAMPLE
[0027] In accordance with the present invention, Sample A comprises a first layer of 60% staple length Tencel® lyocell fibers, Tencel® is a registered trademark of Courtaulds Fibres (Holdings) Limited, and 40% PBX® modacrylic fibers, PBX® is a registered trademark to Kaneka, with a basis weight of about 2.0 oz/yd 2 and a second layer comprising a blend of 42% Tencel® lyocell fibers, 37% PBX® modacrylic fibers, and 21% Twaron® para-aramid fibers, Twaron® is a registered trademark of Enka B.V. Corporation, with a basis weight of about 4.0 oz/yd 2 . The layers were consolidated into a composite flame retardant nonwoven composite fabric by way of hydroentanglement. Subsequently, the composite fabric was advanced onto a three-dimensional image transfer device so as to impart a three-dimensional pattern into the fabric. Table 1 shows the physical test results of the aforementioned fabric. Table 2 also comprises physical test results for a flame retardant component made in accordance with the present invention.
TABLE 1 Composition Sample A ITD Tricot Weight 4.6 oz/yd 2 Bulk 44 mils Tensile MD-Peak (ASTM D-5035) 80 g/cm Tensile CD-Peak 48 g/cm MD Elong. 29.2% CD Elong. 94.4% Elmendorf Tear-MC (ASTM D-5734) 3178 g Elmendorf Tear-CD 2087 g Air Permeability (ASTM D-737) 147 cfm Absorbency 7 sec Thermal Shrinkage, MD (FNA-LB-WI-GL-136) −1.0 Thermal Shrinkage, CD −1.0 Modified Vert. Burn BFT Flame Test 17.1
[0028]
TABLE 2
Composition
face 61% Tencel ® H215 968 1.5
dpf × 1.5″/39% PBX ® 2.0
dpf × 2″ back 42% Panox ®
SM C051 SSC 2 dpf × 2″/35%
PBX ® 2.0 dpf × 2″/23%
Tencel ® H215 968 1.5 dpf × 1.5″
ITD
Tricot
Weight
oz/yd 2
5.5
Bulk
mils, 1-ply
55
Tensile MD-Peak
lbs.
66
Tensile CD-Peak
lbs.
44
MD Elong.
%
34
CD Elong.
%
92
Elmendorf
grams
2192
Tear-MD
Elmendorf
grams
3515
Tear-CD
Air Permeability
cfm
151
Thermal
% @ 140 C./
−1.0
Shrinkage, MD
1.5 min.
Thermal
% @ 140 C./
0
Shrinkage, CD
1.5 min.
TB 604
% weight loss
0.9
[0029] From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein 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.
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A flame retardant bedding article comprises a hydroentangled flame retardant nonwoven component, and more specifically, a bedding article such as a mattress, pillow cover or mattress pad, comprising a structurally stable, flame retardant nonwoven component. The component comprises at least two layers that have a synergistic relationship so as to maintain the structural integrity of the bedding article upon burning.
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RELATED U.S. APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO MICROFICHE APPENDIX
Not applicable.
FIELD OF THE INVENTION
The present invention involves a process and a device for analysis of the structure and constitution of cultivated trained and staked hedgerows such as, for example, rows of vines, or other fruit-bearing bushes, fruit trees, vegetables cultivated in rows (tomatoes, beans, etc.).
This process and device are most especially designed for the implementation and equipping of mobile machines designed for continuous work in trained and/or staked plantations, such as vineyards.
The invention also embodies machines, and most specifically, agricultural machines that involve the application and include this process and device.
BACKGROUND OF THE INVENTION
The analysis of the structure of cultivated or fruit-bearing hedgerows obtained by implementing the process and device of the invention can be used in order to optimize the results of different mechanical or manual inventions to be performed on these hedgerows, whether simultaneously during or subsequent to examining their structure.
The invention can be advantageously applied to the equipment of agricultural machines designed and used for the preliminary pruning of trained and/or staked vines, but it is emphasized and understood in reading the following description that the invention can be implemented to equip other types of agricultural machines such as machines for cultivating the soil, machines for treating plants, harvesting machines, etc. For this reason, reference to a preliminary pruning (or pre-pruning) machine, in the following description, would not be restrictive.
It is recalled that the purpose of the mechanical pre-pruning of the vine is to simplify later pruning work by eliminating the maximum amount of wood before manual pruning. During this preparatory mechanical operation, the wood or vine-shoots whose tendrils are fixed to the wires of the paling, are cut off and released. The main problems of this work consist in:
ensuring passage by the paling of the stakes which create an obstacle to the movement of the cutting instruments, the restriction being that the action of the machine must not be destructive with regard to the stakes and the wires of the paling or its own cutting instruments; for vines trained with cordons, not damaging the cordons, and notably not cutting off any of the fruit.
Most modern pre-pruning machines use rotary cutting systems. Machines with cutting bars are less widespread because disengaging them in order to pass by the stakes can not be done as quickly.
According to the most modern type of machines equipped with rotary cutting systems, the cutting off of the wood is ensured by at least one column of shredding wheels comprising an open circular guide whose periphery forms fingers. Inside the wheels, fixed blades (EP-0 312 126) or a circular saw (FR-2.576.481) ensure that the wood is cut off, acting in combination with the fingers. The cutting tools thus comprised are stacked on two vertical shafts placed on either side of the paling axis during the pre-pruning operation. The rotary instruments acting together for the cutting action are arranged in alternate rows and slightly crossing each other during work; the lower wheel of each paling can be comprised of a pruning shearing wheel for better finishing.
At the entrance to a row of vine stocks, as well as at the exit from this row, the wheel columns are moved out so as to not cut the abutment wires. These paling wires must be correctly installed so as to not become caught or cut off while the machine is operating on the row.
For the passage of stakes having an appropriate diameter, often made of wood or concrete, the wheels roll on the stakes and move away from them automatically, the pressure on the stakes being adjustable so that matching a sizeable density of vine-shoots does not cause an undesired opening of the cutting head; on the contrary, the force for the passage of the stakes must not be excessive so as to not risk damaging them.
However, when the stakes are comprised of steel profiles having a small cross-section, for example, 30 mm angle irons, the spacing between the pilings and the cutting head to allow for the passage of the stakes must be made manually since the stakes can seriously damage the cutting tools by penetrating into the fingers of the rotary guides. In such a situation, the wine growers prefer, in the majority of cases, to use pre-pruning machines with manually controlled opening which requires that the drivers of these machines be vigilant at all times. Very often, to not take any risks, the drivers prefer to open and close the cutting head at a distance from the stakes with a large safety margin, which has the disadvantage of leaving a sizeable quantity of the wood uncut.
When the vines are cordon-cultivated (cordon de Royat), for example, an advantageous application of the invention is to make it possible to keep the pre-pruning cutting instruments above and at a suitable distance from the cordon, in order to remove any risk of damage to the cordon and prevent the elimination of the fruit that is intended to be protected, while keeping the wood pruned as small as possible.
In fact, if it is possible to adjust the height of the cutting instruments of the machine, at the entrance to a row, their position relative to the cordon can be modified when they are moved on this row due to unevenness in the ground, in a manner so that in case of a sudden drop resulting from the passage of the machine into a cavity in the ground, the cordon can be damaged or robbed of its fruits.
Another interesting application of the invention is to perform a measurement of the speed of advancement of the machine, in a manner so as to make possible a permanent adaptation of the functioning conditions of the tools from the measurement of the speed of movement.
In fact, if you consider the pre-pruning machines of the type mentioned above, the peripheral speed of the wheels must be adapted to the speed of movement, an excessive speed of rotation of the wheels has the effect of pulling the wood to the back, whereas a very low speed of the wheels results in pushing the vegetation to the front. The adaptation of the speed of rotation of the wheels to the speed of movement of the machine can be obtained using a speed setting. In practice, the wine-grower chooses an operating speed and adjusts the setting as a result before entering the vine, so that if this speed changes along the way, the cutting instruments will not always work in the best conditions, which causes breakage of the wood, and sometimes, uprooting of the base of the vine.
Another advantage use of the analysis of the structure of the rows of the wines is to allow a setting for the health status of the wine plants.
Wine growing is developing towards a concept of “Precision Wine Growing” (Trademark) which involves noticing, using sensors, all of the significant characteristics of the plant making it possible to consider these characteristics on a GPS map, with regard to short and long-term optimization of the harvest.
The base characteristics of the vine which are essentially the quantity of grapes harvested, the sugar of the grapes, their acidity and the health status of the plant, are collected in a database that is conventionally called “wine base information” and then used to define the conditions in which the pruning, the fertilization, and the selection of the grapes for better vinification, etc.
Knowing the health status of each plant is a data that is of interest to every winegrower who wants to improve the quality of his product. In fact, the map of the vine is developed among other things as a function of the fertilization and the nature of the ground. This development is expressed by the growth, during the vegetative period, of vine-shoots which lose their leaves the following winter.
The health status of the vine is measured when it is pruned; the pruned vine-shoots are recovered, cut into small pieces and weighed. The weight of these vine-shoots will represent the characteristic of health status. It is obtained by comparing the vine-bases, one relative to the other, in comparing deficient health status to good health status. It is known that each health status must correspond to a certain quantity of grapes produced by the plant.
The pruning of the vine has the function of allowing on each vinestock a certain number of buds, which, in the context of their development, will make it possible to determine the volume of the harvest. It is known, for example, that the vine must have an average of 28,000 buds per hectare after the pruning operation. Currently, 28,000 buds/hectare is divided by the number of feet/hectare, which determines uniformly for each vine base, the number of fruit to be looked after per vine base.
Knowing that in a parcel of land, taking into account the heterogeneity of the ground and the conditions of exposure, the health status is not uniform, there is reason, in modern wine-growing, to divide up the 28,000 fruit/hectare not uniformly but as a function of the health status of the vine base.
The measurements made in the context of precision wine-growing must make it possible to measure the health status of each vine base in a manner so as to assign to it an appropriate number of fruit. It is thus necessary to evaluate this health status per vine base in an automated manner because it is unthinkable to perform the operation of weighing the wood for each vine base.
In the document EP-0.974.262, an automated pruning device for plants such as wine plants is described, comprising a chassis supporting a pruning device, a device for acquisition of images making it possible to record the position of the plant relative to the pruning device, and a treatment unit planned in order to send control signals for the adjustment of the position of the pruning device as a function of the images recorded from the trunk or main branch of the plant relative to the pruning device. The device for acquisition of images is comprised of a pair of television cameras placed in a manner so as to be able to point towards the skin, with one at an angle relative to the other.
The automated pruning device described in this document implements a system for image acquisition (television) which does not function without lighting (daylight or substitute lighting) and which functions poorly under strong lighting (the result, for example, of a strong sun) requiring the use of a screen. It does not function during the night without implementing lighting to substitute for the sun.
It does not appear that an automated pruning device according to the document EP-0.974.262 has been put on the market, so that to the knowledge of the applicant, in the domain of agricultural machines, there are not known to exist any processes and devices capable of making, both during the day and the night, analyses of the structure of fruit-bearing hedgerows such as vine rows, and of applying the resulting information of these analyses:
in order to obtain the automatic opening of the cutting head of the pre-pruning machines moving by stepping over the vine row, for passage of the stakes, when they are made of angle irons or have a reduced diameter that allows them to penetrate into the fingers of the shredding wheels; for constant adaptation to the speed of rotation of the wheels to the speed of movement of the machine; with respect to the integrity of the cordon and the fruits to be protected, for cordon-trained vines;—for the measurement of the health status of the vine.
On the other hand, the necessity to proceed with a manual opening of the cutting head for passage of the stakes does not make it possible to perform work at high speed with the current machines. In fact, either the opening of the cutting head is delayed as much as possible in order to cut off the greatest quantity of vineshoots possible, and, in this case, the cutting head comes to hit the stakes causing the stakes to progressively recede, or the opening of the cutting head is anticipated, and, in this case, a sizeable quantity of vegetation is left on the vinestocks next to the stakes.
The present invention proposes to correct the deficiencies mentioned above.
BRIEF SUMMARY OF THE INVENTION
According to the invention, the analysis of the structure of the cultivated hedgerows such as, for example, rows of vines or other fruit rows is obtained using a process according to which is arranged, preferably in front of the working head of the mobile machine designed for continuous work in trained and/or staked plantations, a system for artificial vision functioning by direct transmission and configured in order to make it possible to determine when the light has been blocked between one or more transmitters and one or more receptors placed facing each other on either side of the hedgerow, and in that the information generated by the blockages of the light are treated by an electronic system for analysis programmed or configured in order to analyze the elements of the structure of the hedgerow, and this is to be done both in the day and the night.
According to an interesting implementation of the process, freedom from the influence of interfering solar light is achieved by an artificial illumination system in using a light periodically modulated by the emitters, the receivers only being sensitive to the modulated light and not to the continuous component of the light.
According to another interesting implementation of the process, the significance of the interfering light is reduced by selecting emission and reception wavelengths for which the solar light is relatively weak, i.e. outside of the visible spectrum, either a wavelength of light at 400 nm or greater than 750 nm, and, for example, a wavelength on the order of 950 nm, for which the solar radiation received is particularly weak.
According to another characteristic arrangement of the process of the invention, the electronic analysis system is programmed or configured in order to handle the information generated by the blockages of light, in order to measure the speed of movement of the machine and to adjust the rotational speed of the rotary tools of the machine as a function of the measured speed of movement.
According to another characteristic arrangement of the process of the invention, the electronic analysis system is programmed or configured in order to handle the information generated by the blockage of light, in order to detect the stakes of the hedgerow.
According to another characteristic arrangement of the process of the invention, the electronic analysis system is programmed or configured in order to handle the information generated by the blockage of light, in order to detect the position of the cordon in the vines or other cordon-trained plants.
According to another characteristic arrangement of the process of the invention, the electronic analysis system is programmed or configured in order to use the information generated by the blockage of light, in order to measure the health status of the plants.
The device for analysis of the structure of the fruit-bearing hedgerows according to the invention comprises a system for artificial vision functioning by direct transmission, comprised of one or more emitters and one or more receivers, this system for artificial vision being arranged in such a way that when it is mounted on a machine, one or more of its opto-electronic components can be arranged to face each other, on both sides of the fruit-bearing hedgerow and spanned by it, the device comprising a system for electronic analysis programmed or configured in order to handle the information generated by the blockage of the light, in order to visualize the elements of the hedgerow, whereby this can be done either during the day or at night.
Other advantageous characteristic arrangements of the process and device of the invention are expressed in the dependent claims and described in the following description.
The process and device for mobile scanning according to the invention generally have the advantages, notably in their application to the operation and the equipment of vine pre-pruning machines:
of allowing the detection of the stakes regardless of their composition (wood, metal, plastic), their geometry (L-shaped, T-shaped, round, angled), their diameter (generally between 20 and 250 mm), as well as automatic opening of the pre-pruning head for passage of the stakes, in thus relieving the driver from a repetitive task that requires a large amount of attention, in particular, when the stakes are made of angled iron; of reducing the quantity of vineshoots left around the stakes relative to the machine operating by manual opening; preventing the damage to the stakes or the tools of the machine; preventing damage to the cordon and undesired elimination of the fruit; allowing work at greater movement speeds for the machine; allowing an automatic measurement of the health status of each vine base.
In the application of the invention to the measurement of the vine base, it is understood that each optical barrier that intersects the passage of the pruning wood will generate a signal that makes it possible to determine the cross-section of the vineshoots that cut this barrier. In providing a relatively sizeable number of superposed optical barriers, it is possible to obtain an interesting estimate of the surface of the vineshoots that are cut by the optical barriers.
The correlation tables were made in order to correspond to the cut sections, one health status, and for each vine base. This correlation allows an estimate of the health status with a precision on the order of 8%, which is largely sufficient in order to orient the pruning and thus to determine the number of fruit to be protected per vine base.
According to the invention, the information communicated by the artificial vision system is transmitted to a computer or an on-board calculator in which are recorded, with a large amount of precision, the geographic coordinates of each vine base obtained by GPS, and which makes it possible to record, on the corresponding database, the health status during the operation of pre-pruning. The information could be used purposefully by the wine-grower in order to optimize the pruning and fertilization of his vine.
The pruning adapted to the fertility, must allow an optimum harvest from the perspective of weight, sugar and acidity, and thus provides the wine-growers with the possibility to have a high-quality raw material for vinification, necessary to develop a great vintage.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The purposes, characteristics, and advantages above, and others, are better understood in the description that follows and the attached drawings.
FIG. 1 is a schematic view of a configuration example for artificial vision of the invention.
FIG. 2 is a perspective view showing a pre-pruning machine equipped with a system for artificial vision, moving over a vine row.
FIG. 3 is a detailed perspective view of FIG. 2 .
FIG. 4 is a schematic view of the device ensuring the opening and closing of the cutting head of the machine for passage of the stakes.
FIG. 5 is a schematic view of the device ensuring the regulation of the rotational speed of the rotary tools of the machine as a function of the machine's movement speed.
FIG. 6 is a schematic view of the device ensuring the positioning of the cutting head of the machine as a function of the position of the cordon of the vine row.
FIGS. 7A , 7 B, and 7 C are schematic views showing the process for identification of the vineshoots by the artificial vision system.
FIGS. 8A , 8 B, and 8 C are schematic views showing the process for identification of the stakes by the artificial vision system.
FIGS. 9A and 9B are schematic views showing the process for measurement of the movement speed of the machine by the artificial vision system.
FIGS. 10A and 10B are schematic views showing the process for measurement of the width of the stakes by the artificial vision system.
FIGS. 11A and 11B are schematic views showing the process for measurement of the diameter of the stakes by the artificial vision system.
FIG. 12 is a schematic views showing the process for measurement of the position of the cordon by the artificial vision system.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made to the drawings to describe examples that are of interest, though in no way restrictive, for operating the process and embodiments of the device for analysis of the structure of fruit-bearing hedgerows according to the invention.
This device comprises an artificial vision system ( FIG. 1 ) functioning by direct transmission and comprising, on the one hand, at least one emitter module EM comprising at least one, and preferably, many emitters of light beams E (E 1 , E 2 , E 3 . . . ), and, on the other hand, at least one receiving module RM comprising at least one, and preferably, many receivers of light beams R (R 1 , R 2 , R 3 . . . ). In an advantageous manner, this artificial vision system is comprised of infrared emitters and receivers, and more specifically, near-infrared emitters and receivers.
Preferably, installed in front of the operating head of the agricultural machine, i.e. the cutting head 1 for pre-pruning 2 ( FIG. 2 ), for example, of the type described in the document EP-0 312 126 or in the document FR-2 576 481.
The emitter module EM and receiving module RM are arranged at a distance from each other, for example, at a distance on the order of 800 mm, so as to be able to be placed facing each other, on either side of the fruit-bearing hedgerow HF ( FIGS. 2 to 5 ) when the machine moves along the hedgerow. They are affixed on the vertical elements 3 a of the chassis of the machine using mechanisms, themselves known from the prior-art, that allow the adjustment of the their position, mainly the height, relative to the chassis.
According to the configuration example of the vision system 4 shown in FIG. 1 :
the emitter module comprises, on the one hand, in its upper part, two separated emitters aligned horizontally which are named, respectively, front emitter E 1 and rear emitter E 2 , following the description, and on the other hand, in its lower part, an emitter E 3 ; the space “e” separating the emitters E 1 and E 2 is determined to be lower than the width of the smallest stakes Pi used for the paling of the fruit-bearing hedgerows HF, this space “e” being, for example, on the order of 20 mm; the receiver module comprises three vertical rows or columns of receivers that are named, respectively, front row (receiver R 11 , R 12 , R 13 , . . . R 1 i), rear row (receivers R 21 , R 22 , R 23 , . . . R 2 i) and intermediate row (receivers R 31 , R 32 , R 33 , . . . R 3 j), the lower receiver R 31 of the intermediate row being placed on the lower part of the receiver module.
The vertical rows or columns of receivers can comprise, each one, a relatively sizeable number of receivers. For example:
the front vertical row R 11 , R 12 , R 13 , . . . can be comprised of twelve receivers; the rear vertical row R 21 , R 22 , R 23 , . . . can also be comprised of twelve receivers; the third row of receivers R 31 , R 32 , R 33 , . . . can be comprised of thirteen receivers.
The receivers of each of the three vertical rows can be spaced at a distance that can be between 20 mm and 40 mm in the vertical direction.
The third row R 31 , R 32 , R 33 , . . . occupies an intermediate position in the example shown in FIG. 1 , but it can occupy a different position relative to the two others, in the artificial vision system.
Of course, the vision system could comprise a different number of emitters and receivers otherwise subdivided. It would be, for example, possible to create a vision system in the form of two modules comprising at the same time one or more emitters and one or more receivers, each emitter emitting signals that are only received by the receivers oriented to the emitters.
In an advantageous manner, the base light beam is composed by infrared emitters and receivers or near-infrared radiation.
According to the invention, the constraint of interfering light is eliminated by using light periodically modulated by the emitters, the receivers only being sensitive to the modulated light and not the continuous component of the light.
Sunlight, which is a source of interference for our vision system, is noticeably attenuated by the atmosphere above 750 nm, i.e. in the infrared range, with an absorption peak around 950 nm. So that the beam coming from the vision system can be distinguished from the sunlight, it is advantageous to use a light beam near 950 nm. Thus, for each emitter, an infrared diode has been selected which emits light of wavelength 950 nm when a current goes through it. This diode is excited by a periodic electric signal corresponding to a frequency called “modulation frequency”. The modulation frequency can be fixed in the range between 30 and 56 kHz.
Each receiver R (photo-receiver model TSOP by Vishay Telefunken) is sensitive to any incident beam having a wavelength around 950 nm. It provides, at the output, an active electric signal only if the modulation frequency of the incident beam corresponds to its own frequency. All interfering light sources (sun, incandescent or fluorescent lights) that, by nature or by construction, are not modulated at this frequency, do not give an active signal at the output of the photo-receptor module and are thus integrally filtered.
Each emitter E 1 (front), E 2 (rear) emits, in an alternating manner, for a duration on the order of 500 μs, a modulated light, for example, at a frequency of approximately 32 kHz. This frequency is the frequency that matches the receivers. The front row of receivers R 11 , R 12 , R 13 . . . R 1 i only accepts the signals coming from the front emitter E 1 , while the rear row of receivers R 21 , R 22 , R 23 , . . . R 2 i only accepts the signals from the rear emitter E 2 .
On the other hand, the intermediate row of receivers R 31 , R 32 , R 33 , . . . R 3 j only accepts signals coming from the lower emitter E 3 , designed in order to emit, for example, every 500 μs, a light modulated at a frequency corresponding to the frequency that matches the receivers of the third vertical row R 31 , R 32 , R 33 , . . . . Each receiver supplies an inactive state corresponding to a non-blocked beam and thus the absence of the obstacle between emitter and receiver. Conversely, when it is not excited by an incident ray, it provides an active state corresponding to the presence of an obstacle between emitter and receiver.
According to the invention, blockages of light are handled by an electronic system for analysis programmed or configured in order to visualize the elements of the structure of a fruit-bearing hedgerow or trained hedgerow:
in order to measure the speed of motion of the machine; and/or in order to discriminate the stakes of the hedgerow; and/or in order to detect the position of the cordon; and/or in order to perform a measurement of the health status of the plants.
The electronic system for analysis 7 is comprised:
of an electro-distributor 9 for control of the valve 6 that ensures the forward or backwards movements for the pruning assemblies 14 ; of the flow-regulation valve 11 of the hydraulic circuit for supplying the hydraulic motors 12 ensuring the rotary drive of the pruning assemblies 14 ; of the electronic distributor 16 of the control valve 17 that ensures the vertical movements of the pruning assemblies 14 ; of the precision wine-growing computer (not shown) capable of generating data for determining the health status of the plants.
FIG. 4 shows the artificial vision system 4 - 4 installed in front of the cutting head of the pre-pruning machine in which can be seen, notably the rotary pruning elements 5 and the hydraulic valve 6 ensuring that they are brought together into operating or separation position for the passage of stakes Pi.
The artificial vision system 4 - 4 arranged on both sides of the fruit-bearing hedgerow (vine row or other) moves along the row (according to the arrow AV) which produces information which is analyzed by an electronic system 7 in order to discern the stakes Pi of the hedgerow, to define their width and the speed by which they are passed in front of the vision system 4 - 4 . Once this information has been defined, the electronic system calculates:
1) the moment when it must send an electric current to the control 8 of the electronic distributor 9 that allows the passage of hydraulic fluid into the rear chamber 6 a of the valve 6 which, using a mechanical transmission, ensures the opening or separation of the pruning instruments 5 for the passage of a stake Pi; 2) the moment when it must send an electric current to the control 10 of the electronic distributor 9 allowing the passage of hydraulic fluid to the front chamber of the valve 6 , which ensures via a mechanical transmission the closing or bringing together of the pruning elements 5 after passing a stake.
The calculation thus makes it possible to separate and return the pruning instruments as near as possible to the stakes of the fruit-bearing hedgerows without touching them in order to not damage any of them, while moving away from the uncut vineshoots as little as possible.
FIG. 5 is a view similar to FIG. 4 showing the application of the process and device of the invention for the measurement of the speed of movement of the machine and for the adjustment of the rotational speed of the pruning tools of the cutting head of the machine as a function of the measured speed of movement.
In this application, the artificial vision system 4 - 4 arranged on both sides of the fruit-bearing hedgerow HF moves along the row (according to arrow AV) producing information which is analyzed by an electronic system 7 in order to determine the speed of movement of the machine equipped with the vision system. When the electronic system has defined the speed of movement, it sends an electronic command to the speed control valve 11 which allows hydraulic oil to flow through to supply the hydraulic motors 12 which, by a mechanical linkage, drives in rotation the rotating instruments 5 of the pruning instruments. The electronic command is adjusted until a rotational speed sensor 13 affected by the measurement of the rotation of the rotary instruments 5 indicates to the electronic system 7 a rotational speed has developed that is near the speed of movement of the machine. This movement makes it possible to create feedback by closed loop with the electronic analysis system in order to adjust the rotational speed of the rotary tools 5 as a function of the speed of movement of the machine 2 .
FIG. 6 shows the adjustment of the position of the pruning assembly of the machine relative to the cordon of the staked, cordon-trained vine rows.
The artificial vision system installed in front of the pruning assembly of the machine is made from two columns 14 of rotary tools 5 . The system arranged on both sides of the vine row HF moves along it (in the direction of the arrow AV) producing information which is analyzed by an electronic system 7 in order to recognize and determine the position of the cordon Co relative to the pruning assemblies 14 . Once this analysis is done, the electronic system 7 sends a current:
1/ i.e. if the cordon Co is very low relative to the cutting assemblies 14 , to the command spool 15 of an electronic distributor 16 that allows hydraulic fluid to flow through to the rear chamber 17 a of a valve 17 that uses a mechanical action to lower the cutting assemblies 14 until the cordon is recognized and found at the desired position relative to the cutting assemblies; 2/ or, if the cordon Co is very high relative to the cutting assemblies 14 , to the command spool 18 of an electro-distributor 16 that allows the passage of hydraulic fluid to the front chamber of the valve 17 which, by a mechanical action, makes the cutting assemblies 14 return upwards until the position of the cordon Co relative to the cutting assemblies is correct.
The desired initial position of the cutting assemblies 14 relative to the cordon Co is fixed in advance. This advanced positioning is done by an adjustment of the position of the emitter module ME and receiving module WIR of the vision system 4 - 4 relative to the cutting assemblies 14 using a device for adjustable fixation of the modules on the elements 3 a of the chassis 3 of the machine, as indicated above.
In the following, the function of the artificial vision system is described in the different applications of the invention.
A—Discrimination of the Stakes from the Vegetation
A.1 Identification of the Vegetation ( FIGS. 7A , 7 B, and 7 C)
Taking into account the fact that the process and the device of the invention are most especially designed to equip machines designed to move in the vines, the following description uses the term “vineshoot” to describe the vegetation, this word, however, must be considered as the equivalent of the term “branch” which generally designates the small branches of the plants or shrubs.
A vineshoot Sa has a diameter less than the distance “e” between the emitters E 1 and E 2 . It cuts in sequence the beam E 1 -R 1 i then the beam E 2 -R 2 i.
When the machine moves (arrow AV), the sequence of events for characterizing the presence of a vineshoot is the following:
a) the vineshoot Sa cuts the beam E 1 -R 1 i ( FIG. 7A ) b) the vineshoot does not cut any beam ( FIG. 7B ) c) the vineshoot cuts the beam E 2 -R 2 i ( FIG. 7C ).
A.2 Identification of a Stake ( FIGS. 8A , 8 B, and 8 C).
A stake Pi has an apparent width greater than the distance “e” arranged between the emitters E 1 and E 2 . It simultaneously cuts the beams E 1 -R 1 i and E 2 -R 2 i.
When the machine moves, the sequence of events for characterizing the presence of a stake is the following:
a) the stake Pi cuts only the beam E 1 -R 1 i ( FIG. 8A ) b) the stake cuts the beams E 1 -R 1 i and E 2 -R 2 i ( FIG. 8B ) c) the stake cuts only the beam E 2 -R 2 i ( FIG. 8C )
B—Measurement of the Speed of Movement of the Machine ( FIGS. 9A , 9 B)
The speed of movement of the machine is measured on the vegetation and on the stakes.
B.1 Measurement of the Speed on the Vegetation
a) at the moment t 1 , the vineshoot Sa cuts the beam E 1 -R 1 i ( FIG. 9A ) b) at the moment t 2 , the vineshoot cuts the beam E 2 -R 2 i ( FIG. 9B )
Between t 1 and t 2 , the machine has traveled the distance e.
The speed of movement V of the machine will be e/(t 2 −t 1 )
B. 2 Measurement of the Speed on the Stakes.
The measurement of the speed on the stakes is done in the same manner as the measurement of the speed on the vegetation.
C—Measurement of the Apparent Width of the Stakes ( FIGS. 10A and 10B ).
The speed of movement V of the machine is known and a stake Pi has been identified in traversing as shown above.
C.1 Measurement of the Width of the Stake with the Front Beam E 1 -R 1 i
a) at the moment t 1 , the stake Pi begins to cut the beam E 1 -R 1 i ( FIG. 10A ) b) at the moment t 2 , the stake stops cutting the beam E 1 -R 1 i ( FIG. 10B ).
Between the moment t 1 and t 2 , the machine has traveled the distance L at speed V. The width of the stake Pi will be L=(t 2 −t 1 )*V.
C.2 Measurement of the Width of the Stake with the Rear Beam E 2 -R 2 i.
The width of the stake is measured in the same manner as above with the rear beam E 2 -R 2 i.
D—Measurement of the Health Status of the Vegetation ( FIGS. 11A , 11 B).
The measurement of the diameter of all of the vineshoots at a height corresponding to that of the vertical rows of front receivers R 11 -R 1 i and rear receivers R 21 -R 2 i, makes it possible to deduce the health status of the vegetation, using a correlation table.
The movement speed V of the machine is obtained and a vineshoot Sa is identified by proceeding as indicated above.
D.1 Measurement of the Diameter of the Vineshoot with the Front Beam E 1 -R 1 i:
a) at the moment t 1 , the vineshoot Sa begins to cut the beam E 1 -R 1 i ( FIG. 11A ) b) at the moment t 2 , the vineshoot stops cutting the beam E 1 -R 1 i ( FIG. 11B ).
Between the moment t 1 and the moment t 2 , the machine has traveled a distance d at a speed
V. The Diameter of the Vineshoot will be d=(t 2 −t 1 )*V.
D.2 Measurement of the Diameter of the Vineshoot with the Rear Beam E 2 -R 2 i.
The diameter of the vineshoot is measured in the same manner as above, with the rear beam E 2 -R 2 i.
E—Measurement of the Position of the Cordon Relative to the Lower Cutting Tool Sa of the Cutting Assembly of the Machine.
E.1 Identification of the Cordon ( FIG. 12 )
The cordon Co is distinguished from a stake or from a vineshoot in that it blocks one or more beams E 3 -R 31 , E 3 -R 32 , E 3 -R 33 . . . in the same way when the machine is moving forward.
E.2 Position of the Cordon Relative to the Lower Tool.
Considering that according to a preferred construction,
the horizontal lower beam E 2 -R 31 defines the position of the null reference; the cordon Co is located halfway between the emitter module ME and the receiver module MR (cutting tool centered on the vine row); the emitter module ME and receiver module MR are united with the cutting assembly 14 ; the receivers R 31 , R 32 , R 33 , R 3 j are spaced vertically at the same distance h.
The position of the height of the cordon is given by the highest beam that is blocked (the beam having index k=4 in the example shown in FIG. 12 ).
The height of the top of the cordon, relative to the reference beam E 3 -R 31 is equal to: H=(k−1)*h/2.
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The method for analyzing the structure of cultured hedges, equally applicable by day or by night, for a mobile, continuously-moving machine in tied or staked plantations such as vineyards, includes a system using an artificial vision system, working by transmission, which permits a detection of the shadowing of the light between one or more transmitters and one or more detectors to one side and the other of the hedge. The information generated by said shadows of light are processed by an electronic analysis system, programmed or embodied to examine the elements of the structure of the hedge.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is related to and claims priority from U.S. Provisional Patent Application Ser. No. 60/159,299, filed Oct. 14, 1999, and entitled SINGLE STEP PENDEO-AND LATERAL EPITAXIAL OVERGROWTH OF GROUP III-NITRIDE EPITAXIAL LAYERS WITH GROUP III-NITRIDE BUFFER LAYER RESULTING STRUCTURES.
FIELD OF THE INVENTION
The present invention relates to electronic device structures and fabrication methods, and more particularly to Group III-nitride semiconductor structures and methods of fabrication by pendeo- and lateral epitaxial overgrowth.
BACKGROUND
Gallium nitride (GaN) is a wide-bandgap semiconductor material widely known for its usefulness as an active layer in blue light emitting diodes. GaN is also under investigation for use in other microelectronic devices including laser diodes and high-speed, high power transistor devices. As used herein, “gallium nitride” or “GaN” refers to gallium nitride and III-nitride alloys thereof, including aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN) and aluminum indium gallium nitride (AlInGaN).
High-quality bulk crystals of GaN are currently unavailable for commercial use. Thus, GaN crystals are typically fabricated as heteroepitaxial layers on underlying non-GaN substrates. Unfortunately, GaN has a considerable lattice mismatch with most suitable substrate crystals. For example, GaN has a 15% lattice mismatch with sapphire and a 3.5% lattice mismatch with silicon carbide. Lattice mismatches between a substrate and an epitaxial layer cause threading dislocations which may propagate through the growing epitaxial layer. Even when grown on silicon carbide with an aluminum nitride buffer layer, a GaN epitaxial layer exhibits dislocation densities estimated to be in excess of 10 8 /cm 2 . Such defect densities limit the usefulness of GaN in highly sensitive electronic devices such as laser diodes.
Lateral Epitaxial Overgrowth (LEO) of GaN has been the subject of considerable interest since it was first introduced as a method of reducing the dislocation densities of epitaxially grown GaN films. Essentially, the technique consists of masking an underlying layer of GaN with a mask having a pattern of openings and growing the GaN up through and laterally onto the mask. It was found that the portion of the GaN layer grown laterally over the mask exhibits a much lower dislocation density than the underlying GaN layer or the portion of the GaN layer above the mask openings. As used herein, “lateral” or “horizontal” refers to a direction generally parallel to the surface of a substrate, while the term “vertical” means a direction generally orthogonal to the surface of a substrate.
One drawback to conventional LEO techniques is that separate process steps are required for growing the underlying GaN layer, masking the GaN layer and then growing the lateral layer. Early embodiments of LEO did not place the mask directly on the non-GaN substrate because unwanted nucleation would occur on the mask during nucleation of the GaN layer at low temperatures, preventing adjacent laterally-grown regions from coalescing (or otherwise from growing laterally a desired distance if coalescence is not required). When the mask is placed directly on a GaN layer, unwanted nucleation on the mask is typically not a problem since low temperature nucleation is not required and the growth temperature of GaN is very high, typically above 1000° C. During high temperature growth, unwanted nucleation does not occur on the mask due to the much higher sticking coefficient of gallium atoms on the gallium nitride surface as compared to the mask.
This drawback is addressed with some success by a “single step” process for LEO. Shealy et al. disclosed a process whereby an underlying SiC or sapphire substrate was masked with silicon nitride. The process is referred to as “single step” because it does not require growth of an intermediate layer of GaN between the substrate and the mask. Shealy found that minimizing nucleation on the silicon nitride mask permitted growth of a relatively defect free layer of laterally-grown GaN over the masks. However, under certain circumstances it is desirable to avoid having to minimize nucleation on the mask, yet still be able to grow a relatively defect free layer of GaN in a single step process.
OBJECT AND SUMMARY OF THE INVENTION
Accordingly, there is a need in the art for a method of fabricating a relatively defect-free single crystal film of gallium nitride in a single step process without having to minimize nucleation on the mask layer.
Moreover, there is a need in the art for a method of fabricating a relatively defect-free single crystal film of gallium nitride in a single step process without having to minimize nucleation on the mask layer which provides a conductive buffer layer to permit electrical communication between a conductive substrate and an epitaxial layer of gallium nitride.
It is an object of the present invention to provide a method of fabricating a relatively defect-free single crystal film of gallium nitride in a single step process without having to minimize nucleation on the mask layer.
It is a further object of the present invention to provide a method of fabricating a relatively defect-free single crystal film of gallium nitride in a single step process without having to minimize nucleation on the mask layer which provides a conductive buffer layer to permit electrical communication between a conductive substrate and an epitaxial layer of gallium nitride.
The foregoing and other objects are achieved by a method of fabricating a gallium nitride-based semiconductor structure on a substrate. The method includes the steps of forming a mask having at least one opening therein directly on the substrate, growing a buffer layer through said at least one opening, and growing a layer of gallium nitride upwardly from said buffer layer and laterally across said mask. During growth of the gallium nitride from the mask, the vertical and horizontal growth rates of the gallium nitride layer are maintained at rates sufficient to prevent polycrystalline material nucleating on said mask from interrupting the lateral growth of the gallium nitride layer.
In an alternative embodiment, the method includes forming at least one raised portion defining adjacent trenches in the substrate and forming a mask on the substrate, the mask having at least one opening over the upper surface of the raised portion. A buffer layer may be grown from the upper surface of the raised portion. The gallium nitride layer is then grown laterally by pendeoepitaxy over the trenches.
In another embodiment, the present invention provides a gallium nitride-based semiconductor structure on a substrate. The structure includes a substrate a mask having at least one window therein applied directly on the upper surface of the substrate. An overgrown layer of gallium nitride extends upwardly from the mask window and laterally across the mask, on which polycrystalline material has nucleated and grown.
In another embodiment, the substrate includes at least one raised portion defining adjacent trenches. A mask structure overlays the substrate and a window in the mask exposes at least a portion of the upper surface of the raised portion. An overgrown layer of gallium nitride extends upwardly from the mask window and laterally over the trench and across the mask, on which polycrystalline material has nucleated and grown.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-section of a substrate on which a mask has been patterned.
FIG. 2 is a plan view of a substrate on which a mask has been patterned.
FIG. 3 is a section of a substrate on which a layer of GaN has been epitaxially grown by LEO on a conductive buffer layer.
FIG. 3A is a cross section of a substrate on which a layer of GaN is being epitaxially grown by LEO on a conductive buffer layer, but has not coalesced.
FIG. 4 is a cross section of a substrate on which excessive nucleation on the mask has interrupted the lateral growth of a layer of GaN.
FIG. 5 is a cross section of a substrate on which a layer of GaN has been epitaxially grown in accordance with an aspect of the present invention.
FIG. 6 is a cross section of a substrate on which a layer of GaN has been epitaxially grown in accordance with another aspect of the present invention.
FIG. 6A is a cross section of a substrate on which a pair of raised portions has been formed and a mask layer has been deposited.
FIG. 6B is a cross section of a substrate on which a pair of raised portions has been formed and a mask layer has been deposited using a self-alignment technique.
FIG. 7 is a cross-sectional SEM image showing the interruption of lateral growth of a GaN layer by crystals nucleating on the mask.
FIG. 8 is a plan view SEM image of two GaN stripes in which crystallites on the underlying mask disturbed the epitaxial growth.
FIG. 9 is a cross-sectional SEM of GaN stripes grown in accordance with an embodiment of the present invention using a reflective mask layer.
FIG. 10 is a cross-sectional SEM of GaN stripes grown in accordance with an embodiment of the present invention until adjacent regions have coalesced over the reflective masks.
FIG. 11 is a cross-sectional SEM of a GaN layer grown on a conductive buffer layer over a Si 3 N 4 mask.
FIG. 12 is a cross sectional SEM of a GaN layer grown in accordance with a second embodiment of the present invention.
FIG. 13 is a plan view SEM image of two GaN stripes grown in accordance with the second embodiment of the present invention.
FIG. 14 is a cross-sectional TEM (Transmission Electron Microscopy) image of a layer of GaN grown in accordance with the present invention.
FIG. 15 is a cross-sectional SEM of GaN stripes grown in accordance with an embodiment of the present invention while maintaining a ratio of lateral to horizontal growth rates of 4.2:1.
FIG. 16 is a cross-sectional SEM of GaN stripes grown in accordance with an embodiment of the present invention while maintaining a ratio of lateral to horizontal growth rates of 1:1.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more filly hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. Furthermore, the various layers and regions illustrated in the figures are illustrated schematically. As will also be appreciated by those of skill in the art, references herein to a layer formed “on” a substrate or other layer may refer to the layer formed directly on the substrate or other layer or on an intervening layer or layers formed on the substrate or other layer. References herein to a layer formed “directly on” a substrate or other layer refer to the layer formed on the substrate without an intervening layer or layers formed on the substrate or other layer. The present invention is not limited to the relative size and spacing illustrated in the accompanying figures.
Basic LEO techniques are described in A. Usui, et al., “Thick GaN epitaxial growth with low dislocation density by hydride vapor phase epitaxy,” Jpn. J. Appl. Phys. Vol. 36, pp. L899-902 (1997). Various LEO techniques including pendeoepitaxial techniques are described in U.S. application Ser. No. 09/032,190 “Gallium Nitride Semiconductor Structures Including a Lateral Gallium Nitride Layer that Extends From an Underlying Gallium Nitride Layer”, filed Feb. 27, 1998; application Ser. No. 09/031,843 “Gallium Nitride Semiconductor Structures Including Laterally Offset Patterned Layers”, filed Feb. 27, 1998; application Ser. No. 09/198,784, “Pendeoepitaxial Methods of Fabricating Gallium Nitride Semiconductor Layers on Silicon Carbide Substrates by Lateral Growth from Sidewalls of Masked Posts, and Gallium Nitride Semiconductor Structures Fabricated Thereby” filed Nov. 24, 1998; and application Ser. No. 60/088,761 “Methods of Fabricating Gallium Nitride Semiconductor Layers by Lateral Growth from Sidewalls into Trenches, and Gallium Nitride Semiconductor Structures Fabricated Thereby,” filed Jun. 10, 1998, the disclosures of each of which are hereby incorporated herein by reference.
Referring now to FIG. 1, a substrate 10 is illustrated on which is deposited a mask layer 14 comprising stripes 14 a and 14 b. Although the stripe pattern may continue in a periodic or aperiodic fashion on either side, for convenience only stripes 14 a and 14 b are illustrated. Stripes 14 a, 14 b are characterized in that they have a width (w) and are separated by mask openings or windows 6 having a window length (l). The distance between an edge of stripe 14 a and the corresponding edge of stripe 14 b is defined as the period (p) of the mask pattern, at least with respect to stripes 14 a and 14 b, such that p=W+1.
The mask layer may be deposited using plasma enhanced chemical vapor deposition (PECVD), sputtering, electron-beam deposition, thermal oxidation or other deposition techniques, and patterned using standard photolithographic techniques. The PECVD process is described in detail in Chapter 6 of S. M. Sze, VLSI Technology, 2nd ed., McGraw-Hill 1988. Photolithographic techniques are well known in the art.
As illustrated in FIG. 2, stripes 14 a and 14 b are preferably oriented along the <1{overscore (1)}00> crystallographic direction in the (0001) plane. (Crystallographic designation conventions used herein are well known in the art and need not be described further.) The mask layer 14 may comprise silicon nitride (Si x N y ) or silicon dioxide (SiO 2 ) or any other suitable mask material. If the structure being fabricated is intended for use in an optical device such as an LED or laser diode, the mask layer 14 may comprise a reflective or refractory metal which is stable in ammonia and hydrogen gas, has a melting point in excess of about 1200° C., and is reflective to the desired wavelength. Examples of such metals include tungsten (W) and platinum (Pt). Alternatively, the mask layer could comprise a Bragg reflector which may comprise alternating layers of Si x N y and SiO 2 or other oxides, the design of which is well known in the art.
The substrate may be silicon carbide, sapphire (Al 2 O 3 ), silicon, ZnO, or any other similarly suitable substrate. Silicon carbide substrates are advantageous for a number of reasons. Silicon carbide provides closer lattice and thermal expansion matches for GaN, is thermally and chemically stable, has natural cleave planes, high thermal conductivity, and is transparent to visible wavelengths up to 380 nm. Also, silicon carbide has a distinct advantage in that it is conductive, which permits fabrication of vertical-geometry devices. Silicon carbide substrates may have a polytype of 4H, 6H, 3C or 15R. Preferably, however, the substrate is 6H-SiC (on-axis).
The fabrication of substrate 10 is well known to those in the art. Fabrication of silicon carbide substrates are described, for example, in U.S. Pat. Nos. 4,865,685 to Palmour et al., Re34,861 to Davis, et al., 4,912,064 to Kong et al., and 4,946,547 to Palmour et al., the disclosures of each of which are hereby incorporated by reference. The fabrication of sapphire and silicon substrates is well known in the art and need not be described in detail.
Referring now to FIG. 3, an epitaxial layer 20 may be fabricated by first growing a buffer layer 12 on the surface of the substrate 10 . Epitaxial layer 20 may comprise gallium nitride or a Group III-nitride alloy thereof, such as aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), or aluminum indium gallium nitride (AlInGaN). For a SiC substrate, the buffer layer preferably comprises a layer 12 of Al x Ga 1-x N, where x represents the mole fraction of aluminum present in the alloy and 0<×≦1. In the case of silicon carbide substrates, the buffer layer 12 may have the structure described in copending and commonly assigned U.S. patent application Ser. No. 08/944,547 entitled “Group III Nitride Photonic Devices on Silicon Carbide Substrates with Conductive Buffer Interlayer Structure,” filed Oct. 7, 1997, the disclosure of which is hereby incorporated herein by reference.
Preferably, the topmost buffer layer comprises a mole percentage of Al of between 9% and 12%, and is approximately 1000 to 5000 Å thick. The buffer layer 12 may be made conductive to the SiC substrate by the formation of capped GaN dots on the SiC substrate as described in U.S. patent application Ser. No. 08/944,547 prior to the deposition of the buffer layer.
For sapphire or silicon substrates, a low temperature GaN, AIN or AlGaN buffer may be grown.
As shown in FIG. 3, an AlGaN buffer layer 12 may be grown vertically from the mask openings 6 using a vapor phase epitaxy (VPE) technique such as hydride vapor phase epitaxy (HVPE), or more preferably metal-organic vapor phase epitaxy (MOVPE). In a preferred embodiment, the buffer layer 12 is grown to a thickness larger than the thickness of the mask layer 14 . Once the buffer layer 12 has been grown to a desired thickness, the epitaxial layer 20 is then grown by VPE, preferably in the same run or step as the buffer layer was grown.
As shown in FIG. 3A, epitaxial layer 20 grows laterally (i.e. parallel to the face of the substrate) in addition to vertically. Lateral growth fronts 22 move across the surface of the mask stripes 14 as layer 20 grows.
Referring again to FIG. 3, in one embodiment, epitaxial layer 20 grows laterally until the growth fronts 22 coalesce at interfaces 24 to form a continuous layer 20 of gallium nitride. However, it is not necessary for the growth fronts to coalesce for all applications, as it is possible to fabricate devices in laterally overgrown portions of GaN even if they have not coalesced with adjacent portions. As illustrated in FIG. 9, a useful portion of layer 20 may be fabricated without coalescence of adjacent portions. For example, a laser diode stripe may be fabricated in a region of layer 20 that has not coalesced. For fabrication of an LED, a coalesced layer is preferred. For example, an LED device 250μ wide and 275μ long may be fabricated on a coalesced layer of gallium nitride grown in accordance with the present invention.
The buffer layer 12 and the overgrown layer 20 may be grown using trimethylgallium (TMG), trimethylaluminum (TMA) and ammonia (NH 3 ) precursors in a diluent of H 2 . A suitable MOVPE growth technique is described in greater detail in T. Weeks et al., “ GaN thin films deposited via organometallic vapor phase epitaxy on α (6 H )- SiC (0001) using high-temperature monocrystalline AIN buffer layers,” Appl. Phys. Let., Vol. 67, No. 3, July 1995, pp. 401-403.
While the layer 20 of gallium nitride is growing, nucleation and growth of polycrystalline Al x Ga 1-x N 30 typically begins to occur on the exposed upper surfaces of mask stripes 14 . As illustrated in FIG. 4, if the growth rate of Al x Ga 1-x N on the masks is too high, the lateral growth of layer 20 will be interrupted, preventing it from forming a desired width of laterally overgrown material, and/or preventing it from coalescing with adjacent regions. Essentially, the polycrystalline Al x Ga 1-x N 30 on the mask grows vertically and blocks the lateral growth of the single crystal layer 20 .
The present inventors have discovered that it is possible, by controlling the horizontal and vertical growth rates of layer 20 , to avoid interruption of the laterally growing layer 20 by the polycrystalline Al x Ga 1-x N 30 . By increasing the lateral growth rate of layer 20 relative to its vertical growth rate by a given amount depending on the geometry of the structure, it is possible to grow a layer 20 that will grow to a desired distance despite nucleation on the mask.
Stated differently, by maintaining a sufficiently high lateral growth rate relative to the vertical growth rate of layer 20 , nucleation on the mask need not be controlled, since layer 20 will overgrow any polycrystalline nucleation and growth on the mask.
As a particular example, it has been discovered that by maintaining a ratio of lateral growth rate to vertical growth rate of at least 1:1, it is possible to grow a laterally-overgrown GaN layer on a stripe having a width of 5μ in a pattern with a period of 30μ from a nucleation layer having an Al concentration of about 10%. By maintaining a lateral/vertical growth ratio of 4:1, it is possible to grow a layer of GaN over a mask having 25μ-wide stripes. As shown in FIG. 5, when the lateral growth rate is caused to exceed the vertical growth rate by a sufficient amount, the growth fronts of the layer 20 may coalesce before the polycrystalline AlGaN growing on the stripes 14 a,b grow large enough to block them.
The mechanisms for controlling the relevant growth factors will now be described in detail. The lateral and vertical growth rates of the overgrown layer 20 are controlled by a number of factors. One controlling factor is the so called “fill factor”, defined herein as the ratio of the window length (l) to the stripe period (p). For a given window length, a higher fill factor (i.e. a larger window length for a given period) results in a slower vertical growth rate. Conversely, for a given window length, a lower fill factor results in an increased vertical growth rate. Other factors for controlling the lateral and vertical growth rates are growth temperature, source gas flow rates, source gas nitrogen/gallium ratio, and growth pressure.
If desired, once the laterally growing growth fronts 22 of the layer 20 have coalesced over the masks, the growth conditions can be adjusted to increase the vertical growth rate.
Although dependent on the structure of the particular epitaxial growth reactor being employed, typical growth parameters for the rates described herein are summarized in the following table.
TABLE 1
Typical growth parameters.
Parameter
Value
Growth temperature
1060-1120° C.
Growth pressure
50-200 Torr
N/Ga ratio
2500
Fill factor
0.714-0.833
Lateral growth rate/vertical growth rate
1-4.2
Preferably, a lateral growth rate of about 2-8 μ/hr and a vertical growth rate of about 1-2 μ/hr should be selected. A lateral growth rate of 6.3 μ/hr and a vertical growth rate of 1.5 μ/hr (4.2:1 ratio) may be achieved by growing the layer 20 by MOVPE at 1110° C. and 200 Torr on a patterned mask of Si x N y stripes having a stripe width of 10μ, a window width of 25μ and a period of 35μ for a fill factor of 0.71. The N/Ga ratio during growth of the layer 20 is preferably about 2500. Ratios of lateral growth rate to vertical growth rate may exceed 4.2:1.
To grow the buffer layer, TMG may flowed at 34.8 μmol/min, TMA may be flowed at 6.5 μmol/min and ammonia may be flowed at a rate of 10 slpm in a diluent of H 2 at 15.5 slpm. Once the buffer layer has been grown to a desired thickness, the layer 20 may be grown by flowing TMG at 309 μmol/min and ammonia at a rate of 17 slpm in a diluent of H 2 at 22.5 slpm until the GaN layer has grown to a desired thickness.
A lateral and vertical growth rate of 4.2 μ/hr (1:1 ratio) may be achieved by growing the layer 20 by MOVPE at 1060° C. and 200 Torr on a patterned mask of Si x N y stripes having a stripe width of 10μ, a window length of 25μ and a period of 35μ for a fill factor of 0.71. The N/Ga ratio during growth of the layer 20 is preferably about 2500. It will be appreciated that other ratios, including ratios greater than 4.2:1, may be achieved through selection of other growth parameters.
An embodiment of the present invention utilizing pendeoepitaxial growth is illustrated in FIG. 6 . In this embodiment, the substrate 10 is etched to form at least one raised portion 15 , which defines adjacent recessed areas or trenches 18 on the substrate 10 . FIG. 6 illustrates an embodiment in which a pair of raised portions 15 a, 15 b have been patterned using standard photolithographic techniques and reactive ion etching. Preferably, the height of raised portions 15 (i.e. the depth of trenches 18 ) is at least 1μ. A mask layer 14 , which may be Si x N y , SiO 2 or any other suitable mask is then deposited on the upper surface of substrate 10 , with mask openings 16 made on the upper surfaces of raised portions 15 a, 15 b.
In this embodiment, the substrate 10 may be silicon carbide, sapphire, silicon, gallium arsenide, gallium nitride or another Group III-nitride such as aluminum nitride or aluminum gallium nitride. The fabrication of aluminum nitride substrates is described in U.S. Pat. Nos. 5,858,086 and 5,954,874 to Hunter, the disclosures of which are hereby incorporated herein by reference. Gallium nitride substrates have been fabricated by growing thick epitaxial layers of gallium nitride on a non-GaN substrate. Other methods of obtaining gallium nitride substrates are summarized in A. Usui, et al., “Thick GaN epitaxial growth with low dislocation density by hydride vapor phase epitaxy,” Jpn. J. Appi. Phys. Vol. 36, pp. L899-902 (1997). It will be appreciated by those of skill in the art that when the substrate is a Group III-nitride, homoepitaxial growth may be used.
As shown in FIG. 6, if a buffer layer is required, an AlGaN buffer layer 12 may be grown vertically from the mask openings (or windows) 16 using MOVPE. In a preferred embodiment, the buffer layer 12 is grown to a thickness larger than the thickness of the mask layer 14 . Once the buffer layer 12 has been grown to a desired thickness, the pendeoepitaxial layer 26 is then grown. Pendeoepitaxial layer 26 grows laterally (i.e. parallel to the face of the substrate) over trenches 18 in addition to vertically.
Although nucleation and growth of polycrystalline GaN 30 may be occurring on the mask 14 , it is occurring within trenches 18 , and thus does not interfere with the lateral growth of pendeoepitaxial layer 26 .
FIG. 12 is a cross sectional SEM of a pendeoepitaxial GaN layer grown in accordance with this embodiment of the invention. Polycrystalline AlGaN material is evident within the trench, but does not interfere with the lateral growth of the GaN layer.
It will be readily appreciated that a trench depth of 1μ is exemplary. Trenches 18 may be fabricated with depths less than or greater than 1μ if desired or necessary depending on the rate of polycrystalline growth on the mask or the width of the pendeoepitaxial layer to be grown.
In one embodiment, pendeoepitaxial layer 26 grows laterally until opposing growth fronts 22 coalesce at interfaces 24 to form a continuous layer 26 of gallium nitride. However, as mentioned above, it is not necessary for the growth fronts 22 to coalesce for all applications, as it is possible to fabricate devices in laterally overgrown portions of GaN even if they have not coalesced with adjacent portions.
FIG. 13 is a plan view SEM image of two pendeoepitaxial GaN stripes grown in accordance with this embodiment of the present invention.
For the embodiment illustrated in FIG. 6, alternative methods of forming the mask layer 14 are illustrated in FIGS. 6A and 6B. As discussed above, raised portions 15 may be formed using standard etching techniques. Typically, this involves patterning the surface of a substrate with an etch mask, etching the substrate to the desired depth, and then removing the etch mask. As shown in FIG. 6A, after the etch mask has been removed, the mask layer 14 may be formed on the surface of substrate 10 by PECVD. Windows 16 are then opened in mask 14 to reveal the upper surfaces of raised portions 15 .
Because of the tolerance limitations of photolithographic techniques, when the windows 16 are opened in mask 14 , it is difficult to align the edges of windows 16 with the edges of raised portions 15 . Thus, there is some overlap 17 of the mask 14 onto the upper surfaces of raised portions 15 .
A simplified method of forming mask 14 is illustrated in FIG. 6 B. In this method, an etch mask 19 is applied to the surface of substrate 10 , and substrate 10 is etched to form trenches 18 . Mask 14 is deposited after etching trenches 18 but prior to removing etch mask 19 . In this technique, mask 14 preferably comprises a thin mask layer of about 50-200 Å in thickness. Mask 14 may comprise Si x N y , SiO 2 , or any other suitable mask material. Etch mask 19 is then removed, revealing the upper surfaces of raised portions 15 . The edges of windows 16 in mask 14 are thereby self-aligned with the edges of raised portions 15 . Thus, with this technique, only a single masking step is required and it is not necessary to use photolithographic techniques to open windows 16 in mask layer 14 .
FIG. 7 is a cross-sectional SEM image showing the interruption of lateral growth of a GaN layer by crystals nucleating on the mask.
FIG. 8 is a plan view SEM image of two GaN stripes in which crystallites on the underlying mask disturbed the epitaxial growth.
FIG. 9 is a cross-sectional SEM of GaN stripes grown in accordance with an embodiment of the present invention using a reflector mask layer.
FIG. 10 is a cross-sectional SEM of GaN stripes grown in accordance with an embodiment of the present invention until adjacent regions have coalesced over the masks.
FIG. 11 is a cross-sectional SEM of a GaN layer grown on a conductive buffer layer over a Si 3 N 4 mask.
FIG. 14 is a cross-sectional TEM (Transmission Electron Microscopy) image of a layer of GaN grown in accordance with the present invention. The defect densities observed indicate an estimated reduction from approximately 10 9 /cm 2 in the regions over the windows to approximately 10 6 /cm 2 in the regions above the mask stripes.
EXAMPLE 1
A patterned mask of Si x N y stripes having a stripe width of 10μ, a window length of 25μ and a period of 35μ for a fill factor of 0.715 was applied to a 6H-SiC substrate. The stripes were arranged parallel to the <1{overscore (1)}00 > direction. A 0.5μ thick Al 0.1 Ga 0.9 N buffer layer was grown by MOVPE by flowing TMG at 34.8 μmol/min, TMA at 6.5 μmol/min and ammonia at 10 slpm in a diluent of H 2 at 15.5 slpm at 1050° C. and 76 Torr for a total of 80 minutes. Following growth of the buffer layer, an epitaxial layer of GaN was grown by MOVPE by flowing TMG at 309 μmol/min and ammonia at 17 slpm in a diluent of H 2 at 22.5 slpm at 1110° C. and 200 Torr for 45 minutes. The ratio of lateral to vertical growth under these conditions was approximately 4.2:1. FIG. 15 is an SEM image a cross section of the resulting GaN layer.
EXAMPLE 2
A patterned mask of Si x N y stripes having a stripe width of 10μ, a window length of 25μ and a period of 35μ for a fill factor of 0.715 was applied to a 6H-SiC substrate. The stripes were arranged parallel to the <1{overscore (1)}00> direction. A 0.5μ thick Al 0.1 Ga 0.9 N buffer layer was grown by MOVPE by flowing TMG at 34.8 μmol/min, TMA at 6.5 μmol/min and ammonia at 10 slpm in a diluent of H 2 at 15.5 slpm at 1050° C. and 76 Torr for a total of 80 minutes. Following growth of the buffer layer, an epitaxial layer of GaN was grown by MOVPE by flowing TMG at 309 μmol/min and ammonia at 17 slpm in a diluent of H 2 at 22.5 slpm at 1060° C. and 200 Torr for one hour. The ratio of lateral to vertical growth under these conditions was approximately 1:1. FIG. 16 is an SEM image a cross section of the resulting GaN layer.
In the specification and drawings, there have been set forth preferred and exemplary embodiments of the invention which have been included by way of example and not by way of limitation, the scope of the invention being set forth in the accompanying claims.
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A method of fabricating a gallium nitride-based semiconductor structure on a substrate includes the steps of forming a mask having at least one opening therein directly on the substrate, growing a buffer layer through the opening, and growing a layer of gallium nitride upwardly from the buffer layer and laterally across the mask. During growth of the gallium nitride from the mask, the vertical and horizontal growth rates of the gallium nitride layer are maintained at rates sufficient to prevent polycrystalline material nucleating on said mask from interrupting the lateral growth of the gallium nitride layer. In an alternative embodiment, the method includes forming at least one raised portion defining adjacent trenches in the substrate and forming a mask on the substrate, the mask having at least one opening over the upper surface of the raised portion. A buffer layer may be grown from the upper surface of the raised portion. The gallium nitride layer is then grown laterally by pendeoepitaxy over the trenches.
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BACKGROUND
This application relates to gaming machines or terminals and security provisions therefore. In particular, the application relates to improved methods and apparatus for affording to authorized persons access to secure areas of gaming machines.
Gaming machines or terminals, such as slot machines, typically include a number of secure or locked areas which are accessible only to authorized personnel. As used herein “area” may refer to a region closed by a door, or a lockable device, such as a switch. Such areas may include storage hoppers and overflow “drop” boxes for coins, currency, tokens or other valuable items used in playing a game, bill or ticket storage stackers, operating mechanisms, electronic control panels, auxiliary equipment such as printers, and so forth. Access to a given machine may be required from time to time by any of a number of different persons, e.g., currency-handling personnel for filling and emptying coin hoppers, drop boxes or bill stackers, service personnel for performing routine maintenance or service functions, repair technicians for correcting malfunctions, and the like. Since most such personnel require access to fewer than all of the available secure areas of a machine, and since it is desired to limit access to machine areas as much as possible for security reasons, it is necessary to provide each such area with a separate lock. Heretofore, such locks have been mechanical devices which are unlocked with a mechanical key. Thus, for any given machine, a number of different keys may be required, and it may be necessary to provide multiple copies of any one key for different personnel, who may require access to an area for different reasons, or who work different shifts, or the like.
The existence of a large number of keys in circulation is an inherent security risk. Furthermore, when a gaming establishment needs to access many machines at a time, such as to do hopper fills or drop box services, most of the service time is spent searching for the proper keys to unlock the machines, which is inefficient and costly. Also, each time an employee leaves the employ of a gaming establishment, the gaming machines or areas thereof to which the employee had access must be re-keyed. This can constitute a significant expense.
SUMMARY
There is disclosed herein a method and apparatus for selectively controlling access to one or more areas of a gaming machine, which avoids the disadvantages of prior techniques while affording additional structural and operating advantages.
An important aspect is the provision of a method and apparatus of the type set forth which is characterized by significantly increased security.
Another aspect is the provision of a method and apparatus of the type set forth which affords significant economies of time and money.
An important aspect is the provision of a method and apparatus of the type set forth which minimizes the need for mechanical keys.
In connection with the foregoing aspect, another aspect is the provision of an apparatus which utilizes electrically operable lock mechanisms under control of processors programmed to respond to the input of personnel identification data by a person seeking access to a machine, to provide access to only those areas for which the person is authorized.
Another aspect is the provision of an apparatus of the type set forth, wherein a plurality of gaming machines may be in communication with and under common control from, a host computer.
A further aspect is the provision of an apparatus of a type set forth with a mechanical override which can be used in the absence of electrical power or in the event of malfunction or other emergency.
In connection with the foregoing aspect, a further aspect is the provision of an apparatus of the type set forth, wherein the mechanical override is normally disabled when the gaming machine is normally electrically powered.
In connection with the foregoing aspects, a further aspect is the provision of an apparatus of the type set forth, which provides an indication when the override has been utilized.
Another aspect is the provision of a system of the type set forth which monitors the states of all gaming machine doors and lock mechanisms.
Certain ones of these and other aspects may be attained by providing apparatus for selectively controlling access to one or more of plural areas of a gaming machine, the apparatus including plural electrically operable lock mechanisms respectively associated with the areas and movable between unlocked and locked conditions relative to the areas; control circuitry including a processor operating under control of a stored program and coupled to each of the lock mechanisms for controlling operation thereof; a data storage and retrieval system adapted to communicate with the processor and including a storage medium for storing data including personnel identification data and access authorization data indicative of the areas, if any, of the machine for which a person seeking access to the machine is authorized; and a data input device coupled to the processor for inputting at least personnel identification data identifying a person seeking access to the machine, the processor being responsive to input personnel identification data for operating one or more lock mechanisms in accordance with access authorization corresponding to an identified person.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated.
FIG. 1 is a perspective view of a prior art gaming machine;
FIG. 2 is a functional block diagram of system for controlling access to gaming machines;
FIG. 3 is a functional block diagram of a lock processor and associated elements of control/monitor circuitry of a gaming machine of FIG. 2 ;
FIG. 4 is a functional block diagram of an embodiment of data input device for a gaming machine of FIG. 2 ;
FIG. 5 is a diagrammatic top plan view of a door lock mechanism and associated sensing apparatus for a door of a gaming machine of FIG. 1 , with the door in its closed condition and the lock bolt in its locked condition;
FIG. 6 is a view similar to FIG. 5 , with the lock bolt in its unlocked condition;
FIGS. 7A and 7B are rear elevational and top plan views of the lock bolt of FIG. 5 ;
FIGS. 8A and 8B are top plan and front elevational views of a manual override unlocking cam for the lock mechanism of FIGS. 5-7 ;
FIGS. 9A-9D are views similar to FIGS. 5 and 6 of the lock mechanism, illustrating various positions of the mechanism during unlocking with a manual override key and the unlocking cam of FIGS. 8A and 8B ;
FIG. 10 is a flow chart diagram of program software for the host computer of the system of FIG. 1 ;
FIG. 11 is a flow chart diagram of program software for a local processor of one of the gaming machines of FIG. 1 ;
FIG. 12 is a flow chart diagram of program software for a lock processor of a gaming machine of FIG. 1 ; and
FIGS. 13A and 13B are diagrammatic views of a lock mechanism controlling enablement of a standard manual latch assembly.
DETAILED DESCRIPTION
Referring to FIG. 1 , there is illustrated a prior art gaming machine or terminal 10 having a housing 11 provided with a display area 12 . Depending upon the type of gaming machine and the nature of the game, there may be provided a number of user interface devices, which may include a button array or key pad, touch screen, joy stick, lever arm, or the like. The machine 10 may include a coin or token slot 13 for receiving the player's wagers and which communicates with an associated hopper 13 a . Also, depending upon the nature of the machine, it may include a bill or card slot 14 for receiving player wagers, which is typically provided with an associated bill or card validator (not shown) and a bill or card stacker 14 a . There may also be provided a payout bin 15 for receiving dispensed payout of coins or tokens, and/or a printer 15 a associated with a dispensing slot for dispensing cards, bills or the like. Typically, a drop box 16 is provided for receiving overflow from the hopper 13 a.
Access to the interior of the gaming machine 10 may be provided through a main door 17 which includes an associated manual, key-actutable lock mechanism. In addition, a number of the other elements of the machine, such as the hopper 13 a , the stacker 14 a , the printer 15 a , and the drop box 16 may also be provided with manual lock assemblies, and may be accessible from inside or outside of the machine 10 . In addition, there may be provided certain switches, such as a privilege switch 18 , provided with an associated lock, and one or more circuit boards 19 , which may be provided with associated lock assemblies for controlling enablement thereof.
Referring to FIG. 2 , there is illustrated an access control system 20 for a plurality of gaming machines 30 under common control of the a computer 21 . Each of the gaming machines 30 may be generally the same type as the gaming machine 10 , described above, except that instead of having mechanical, key-actuated lock assemblies, it is provided with electrically operated lock mechanisms, as will be described more fully below.
The host computer 21 , which may be located in a central location in a gaming establishment, includes a processor 22 , which may comprise one or more microprocessors, and an memory or associated storage device 23 on which may be stored a database 24 including identifications of all of the gaming machines 30 , as well as personnel identification data for all applicable personnel, and access authorization data indicating which, if any, lockable areas of which machines 30 each person is authorized to access. The processor 22 is coupled to a communications circuit 25 for communication with other devices. The host computer 21 may also be provided with one or more input devices 26 , which may include a keyboard, mouse or the like, as well as a display 27 , which may include a CRT or LCD display screen or other types of display devices. Additionally, if desired, other accessory devices, such as printers, modems, speakers, etc. may be coupled to the host computer 21 in a known manner. The communications circuit 25 is coupled through a communication link 28 to each of the gaming machines 30 . The communication link 28 may be a wired link, such as a cable network or the like, or a wireless link, such as an RF link.
While internal details have been illustrated on only one of the gaming machines 30 in FIG. 2 , it will be appreciated that similar details are included in each of the gaming machines 30 and, while only three such machines are depicted in FIG. 2 , the dotted lines between the last two machines signifies that there may be any number of intervening machines therebetween. The gaming machines 30 may be of the same or of different types, but all will include features similar to those illustrated in the first machine 30 .
In particular, each gaming machine 30 includes a local controller 31 which may include a processor 32 , such as a suitable microprocessor, coupled to an associated memory or storage device 33 and to a communications circuit 34 which is, in turn, coupled to the communications link 28 . The machine 30 is provided with an input device 35 coupled to the processor 32 for user input of information. Referring to FIG. 4 , the input device 35 may include a suitable card reader 36 for reading data on a personal data card 37 . Each applicable person may be provided with a personal identification card, which may contain personal identification data which identifies that person. When a person seeks access to a particular machine 30 , the personal identification card 37 is inserted in the card reader, which reads the data therefrom and transmits it to the processor 32 . The input device 35 may also include a keypad 38 for user input of information, such as a PIN number, to confirm identification and inhibit unauthorized use of another person's personal identification card. Alternatively, the input device 35 could include simply a key pad 38 for user input of all applicable identification information. The card reader 36 and card 37 may be magnetic devices. Alternatively, the card 37 may be a “smart” card with built-in electronics, in which case, the card reader 36 would be a suitable associated “smart” card reader. It will be appreciated that other types of input devices could also be used, including biometric identifiers, such as finger print readers, or the like.
Each gaming machine 30 also includes one or more lock mechanisms 40 , each associated with one of the lockable “areas” described above. In the illustrated embodiment, three of the lock mechanism 40 have been shown in the first gaming machine 30 in FIG. 2 , but the dotted lines between the last two lock mechanism 40 indicate that any number of intervening lock mechanism 40 may be disposed therebetween. It will also be appreciated that fewer than three lock mechanism 40 may be provided in certain machines. Each lock mechanism 40 has associated therewith control/monitor circuitry 41 , which is coupled to the communications circuit 34 of the local controller 31 .
Referring in FIGS. 3 and 5 - 7 B, there are illustrated details of a lock mechanism 40 and the control/monitor circuitry 41 thereof for a typical lockable area, in this case the access to the area being controlled by a door 50 on which the lock mechanism 40 is mounted. The lock mechanism 40 includes a lock bolt 42 in the form of an elongated member provided with a tapered cam surface and 43 at one end thereof (see FIG. 7A ). The bolt 42 may be substantially rectangular in transverse cross section and may be provided with a rectangular slot 44 for receiving an associated magnet 45 adapted for cooperation with an associated electromagnetic coil 45 a for controlling reciprocating movement of the bolt 42 in locking (toward the right) and unlocking (toward the left) directions, as viewed in the figures, depending upon the direction of electrical current through the coil, all in a known manner. The bolt 42 may be provided with a projecting pin 42 a , for a purpose to be described below, and is also provided along one face with a pair of spaced-apart detent recesses 46 and 47 . Formed transversely through the bolt 42 are two longitudinally spaced-apart bores 48 and 49 . The door 50 is movable between open (not shown) and closed positions relative to an associated door jamb 51 which includes suitable keeper structure for the bolt 42 , which may include a lock slot 52 dimensional to receive the bolt 42 .
There is also provided a detent ball 53 biased by a spring 54 into engagement with the lock bolt 42 . When the bolt 42 is in its locked position, illustrated in FIG. 5 , the detent ball 53 will engage in the detent recess 46 while, when the bolt 42 is in its unlocked position, illustrated in FIG. 6 , the detent ball 53 will engage in the detent recess 47 , thereby to prevent accidental movement of the bolt 42 from these positions.
Referring also to FIGS. 8A and 8B , the lock mechanism 40 may also include a manual override unlocking cam 55 having an arm 56 projecting from one end thereof and cooperating with the main body of the cam to define a shoulder 57 . Formed through the cam 55 is a key aperture 58 which, for simplicity, is illustrated as square in shape, although it will be appreciated that it could have any desired shape. The unlocking cam 55 is disposed adjacent to the bolt 42 for pivotal movement relative thereto, as will be explained more fully below.
The control/monitor circuitry 41 includes a lock processor 60 (see FIG. 3 ), which may be a suitable microprocessor, which communicates via a communications circuit 60 a with the local controller 31 , as explained above. Mounted on the door 50 is an optical door emitter 61 and an optical door receiver 62 . Mounted on the door jamb 51 is a prism 63 , which is positioned so as to be opposite the emitter and receiver 61 and 62 when the door 50 is in its closed position, illustrated in the drawings. The emitter 61 may be an LED and the receiver 62 may be a suitable light sensor, such as a photocell or the like. When the door 50 is in its closed positioned, the emitter 61 emits a light beam which passes into the prism 63 and is internally reflected thereby back to the receiver 62 along an optical path indicated by the broken line in FIG. 5 . When the door 50 is not in its closed position, the optical path between the emitter 61 and the receiver 62 will be interrupted.
The control/monitor circuitry 41 also includes a similar bolt locked emitter 64 and a bolt locked receiver 65 cooperating with an associated prism 66 so that, when the bolt 42 is in its locked position illustrated in FIG. 5 , a light beam emitted from the emitter 64 will pass through the bore 48 into the prism 66 and back through the bore 49 to the receiver 65 . This optical path will be interrupted when the bolt 42 is not in its locked position. There is also provided a bolt unlocked emitter 67 and a bolt unlocked receiver 68 cooperating with a prism 69 so that, when the bolt 42 is in its unlocked position, illustrated in FIG. 6 , a light path will be established from the emitter 67 through the bore 49 into the prism 69 and back through the bore 48 to the receiver 68 . This path will be interrupted when the bolt 42 is not in its unlocked position.
As can be seen in FIG. 3 , the optical emitters 61 , 64 and 67 , the optical receivers 62 , 65 and 68 and the coil 45 a are all coupled to the lock processor 60 . It is a significant aspect of the system 20 that the optical emitters 61 , 64 and 67 can be modulated and, to this end, they are all connected to a modulator 60 a which is, in turn, connected to the lock processor 60 . The modulation of the light beams generated by the emitters could be of any of a number of different types, but may be as simple as intermittently operating the emitters in patterns which may be predetermined but are preferably random, with random on times and random off times. This greatly enhances the security of the system by minimizing the possibility of blinding the optical receivers with an external light source. The software of the lock processor 60 can, for example, signal an error or alarm condition if a receiver is receiving when its associated transmitter is not transmitting or, when the associated door or lock bolt is in a position wherein the optical path should be completed, the receiver is not receiving when its associated emitter is transmitting.
It will be understood that the particular type of lock mechanism structure shown on the drawings is simply for purposes of illustrating the applicable principles, and that other known lock mechanism structures could also be utilized.
While the illustrated embodiment utilizes optical emitters and receivers for the door and lock bolt monitoring functions, it will be appreciated that other types of position-sensing devices could be utilized, although for some such devices the modulation function may not be feasible. Also, while a locking mechanism for a door has been described in detail, it will be appreciated that the locking mechanism for other types of lockable “areas” in the gaming machine 30 could use other known types of condition sensing or detecting devices.
In operation, it would be appreciated that the lock processor 60 can determine from the conditions of the emitters and receivers whether or not a door is in its closed position, and whether a lock bolt is in its locked position, unlocked position or neither, and this information can be communicated to the local controller 30 and then to the host computer 21 .
The operation of the electrically operated locking mechanism described above is dependent upon the presence of electrical power. It is, of course, possible to provide a battery back-up system in the event of failure of the local power supply, but that is of limited utility. It is desirable to have a means for operating the lock mechanism 40 in the absence of a power supply, such as in the event of a power outage or when a gaming machine is removed for service or inspection, as at a gaming control board facility, and not connected to a power supply. Referring to FIGS. 8A , 8 B and 9 A- 9 D, there is provided a manual override unlocking mechanism utilizing the mechanical unlocking cam 55 of FIGS. 8A and 8B , the shoulder 57 and arm 56 of which are diagrammatically illustrated in FIGS. 9A-9D . When the lock bolt 42 is disposed in its locked condition, illustrated in FIG. 9A , the unlocking cam 55 is disposed for pivotal movement about an axis substantially parallel to the pin 42 a in a counter clockwise direction, illustrated by the arrow. In this initial position, the arm 56 of the unlocking cam 55 is disposed for engagement with the lock bolt pin 42 a , while the shoulder 57 is disposed for engagement with a pin 66 a on the prism 66 . The prism 66 is mounted for movement in directions parallel to the movement of the lock bolt 42 . Thus, when a key is inserted in the key aperture 58 and the cam 55 is rotated in the direction of the arrow, both the lock bolt 42 and the prism 66 will be moved to the left, passing first through the intermediate positions illustrated in FIG. 9B and moving ultimately to the positions illustrated in FIG. 9C , wherein the lock bolt 42 is in its unlocked condition. Note that if the cam 55 is now rotated back in the opposite direction, it will have no effect on the lock bolt 42 or the prism 66 , so that the door can be unlocked, but not locked with the override key.
Another important aspect is that the system 20 can recognize if there has been unauthorized tampering with the machine 30 with an override key. Thus, when the lock bolt 42 is returned to its locked condition, such as by an electrical control signal, as illustrated in FIG. 9D , the prism 66 will remain in the position of FIG. 9C , so that the optical path between the emitter 64 and the receiver 65 will be interrupted. Thus, the system can immediately recognize that the override key has been used and appropriate steps can be taken. Once this fact is recognized, the prism 66 can be selectively or automatically reset to its normal position of FIG. 9A , as by use of a suitable solenoid.
While the lock mechanism 40 and control/monitor circuitry 41 are designed to provide direct control of access to a lockable area of a gaming machine, by directly locking and unlocking a door or some other lockable device, it could also be utilized for indirect control of access. More specifically, in existing machines with standard mechanical latch assemblies, electrically controllable lock mechanisms could be utilized to control access by controlling the enablement and disablement of the standard mechanical latch assemblies. Referring to FIGS. 13A and 13B , there is illustrated a standard mechanical door latch assembly 120 having an actuating lever 121 and an associated lock cam 122 operable by an associated mechanical key (not shown) receivable in a key hole 123 . Referring to FIG. 13B , in normal operation the key would be used to rotate the cam 122 in a counter clockwise direction to unlatch the door latch assembly 120 in a known manner. When the key is then rotated in the opposite direction, the actuator 121 returns to its original position to latch the assembly. The lock mechanism may include a solenoid 125 with a plunger 126 which is moveable between a retracted position shown in FIG. 13B , which does not interfere with the operation of the cam 122 , and an extended position shown in FIG. 13A , blocking rotation of the cam 122 from its normal rest position. The system could be operated so that, when the solenoid 125 is de-energized, its plunger 126 is extended, thereby disabling the door latch assembly 120 and preventing access by use of the mechanical key. When the solenoid 125 is energized, the plunger 126 is retracted, permitting operation of the door latch assembly 120 by use of the mechanical key.
The arrangement of FIGS. 13A and 13B could be utilized in connection with the manual override unlocking cam 55 in the electrically controlled system described above in connection with FIGS. 9A-9D . In this case, the solenoid plunger 126 could be extended to block movement of the unlocking cam 55 when the solenoid 125 is energized, which would normally be the case whenever the system 20 is powered up and retracted in the event of a power loss to permit the use of the override key. Thus, it would not be possible for someone to attempt to tamper with the gaming machine using an override key when the system 20 was powered.
While, in the embodiment described above, the lock bolt 42 is moved by a coil and magnet arrangement, it will be appreciated that other types of electrically controlled motive devices could be utilized. For example, a stepper motor could be utilized.
Referring to FIGS. 10-12 , the operation of the system 20 will be described in greater detail. FIG. 10 illustrates a flow chart 70 for a software program of the host computer 21 in connection with the access control system 20 described herein. Initially, at 71 , the input devices 26 , such as a keyboard, are enabled, all variables are initialized, all tables are read from storage and all communication ports are initialized and timers are set and interrupts enabled. Then, at 72 , communication is established to all of the gaming machines 30 and information is gathered from the lock processors 60 via the local controllers 31 . Next, at 73 , the routine builds a new table containing the states of all of the lock bolts and doors from the information received from the individual gaming machines. The date and time of day may be added to the table for histogram purposes. Then, at 74 , the routine again communicates with all of the gaming machines 30 and control signals are sent thereto to enable or disable of the lock mechanisms 40 thereof in accordance with the table at 73 .
Then, at 75 , the system displays the states of all of the gaming machines on the display 27 and may produce messages on the display if any states are changed from the previous table. Messages may be steady state or flashing and in various colors, depending upon the particular condition detected. Then, at 76 , the new table is stored and if there are any changes from the old table to the new, the new table is added to the end of the file containing the old table. Then, at 77 the program loops and waits for an input from the input devices 26 or a timer interrupt. If, at 78 , a timer interrupt is received, the program returns to 72 , and if a key board or other input device input is received, it proceeds to 79 and utilizes the input commands to build messages to send to the gaming machines for locking or unlocking different lock mechanisms in accordance with the commands and then, at 79 a , communicates those messages to the gaming machines and returns to 72 . These commands are communicated as CNS or CSN signals to the coil 45 a of the designated lock mechanism 40 of the designated gaming machines 30 for respectively locking or unlocking the lock bolt 42 .
It will be appreciated that, with the use of this program the system 20 can readily detect error or fault conditions in the states of the gaming machines 30 . For example if a door 50 is open, but its associated lock bolt 42 is in its locked position, this would be an error condition which would merit investigation. Similarly, if a lock bolt 42 were to remain in neither a locked nor an unlocked condition, this would be recognized as a fault condition. Also, the system can readily determine whether or not the sensed states of the machine are in accordance with the most recently commanded states and indicate any discrepancies.
In FIG. 11 there is illustrated a flow chart for a software program 80 for the processor 32 of a local controller 31 . At 81 , the timers, interrupts and communications port are enabled. The timer is used to interrupt the controller so that data from all of the lock mechanism 40 of the machine 30 can be gathered at regular intervals. The communications port is used to communicate with the host computer 21 . At 82 , when the interrupt timer times out, the controller communicates with the various lock mechanisms 40 to gather the states of the doors and lock mechanism via the optical emitters and receivers and then, at 83 , builds a table of these lock and door states to be transmitted to the host computer 83 and then returns at 84 to the main loop. When the program sees a communications interrupt from the host computer 21 at 85 , it transmits the table built at 83 to the host 21 and then returns at 86 to the main loop.
Referring to FIG. 12 there is illustrated a software program 90 for a lock processor 60 of FIG. 3 . At 91 the program sets up timer and communications interrupts and then loops waiting for a timer or communication interrupt to occur. The beginning of a timer interrupt subroutine is designated 92 , in which the routine first checks at 93 to see if the lock bolt coil 45 a of a lock mechanism to be mounted is energized. If it is, the system recognizes at 94 that the condition of the lock bolt is changing, and then at 95 sets a changing state timer and, when it times out, exits at 96 back to 93 to again check to see if the coil is energized. The program will go through this loop ten times and, on the tenth time will produce an error code indicating a fault. If, at 93 , the coil is not energized, then the bolt is not changing states and the system should be able to get a good reading from the sensors, so the system proceeds to 97 to check to see if the lock/door combination are in a state 1, wherein the lock bolt is in its unlocked condition and the associated door is in its opened condition, which would be a service state condition. If so, the routine, at 98 , sets the service state flag and proceeds to 99 to add that state to the table of states of lock and door sensors and then returns at 100 to the main loop.
If, at 97 , the lock/door combination is not in state 1, the routine checks at 101 to see if it they are in a state 2, corresponding to the bolt in its unlocked condition and the door closed, which is another service state condition. If so, the routine again proceeds to 98 and, if not, next checks at 102 to see if they are in state 3, corresponding to the lock locked and the door closed, which is the normal operating state. If so, the routine, at 103 , sets the lock locked and door closed flag. If not, the routine next checks at 104 to see if the door/lock combinations in state 4, corresponding to the lock locked and the door opened, which is an error state. If so, the routine, at 105 sets the corresponding flag.
Note that each door/lock combination has two acceptable lock bolt conditions, i.e., locked or unlocked, and two acceptable door conditions, i.e., closed or opened. This means there are four possible combinations of lock/door conditions and the routine checks at tests 93 , 101 , 102 , and 104 for each of those four conditions in sequence. If, at 104 , the answer is no, it means that none of those four acceptable conditions obtains and, therefore, the lock must be broken or has been tampered with. This could be because the lock bolt is stuck or it may be because someone has opened the lock with a manual key, such as the override key, and when that occurs the lock must be taken apart and pieces reset, such as resetting the position of the prism 66 ( FIG. 9( d ).
Thus the routine then proceeds to 106 to check the nature of the fault condition. If the sensors are signaling that the lock is both locked and unlocked, the routine then checks at 107 to see whether the door is opened or closed and sets an appropriate flag at 108 or 109 and then proceeds to 99 . If, at 106 , the sensors indicate that the lock bolt is neither locked nor unlocked, the routine then checks at 110 to seek what condition the door is in and sets the appropriate flag at 111 or 112 and then proceeds to 99 . When the fault code is generated at 96 , indicating that the coil has remained energized, the routine also moves to 106 to signal a broken lock condition.
If a communication interrupt occurs, the routine at 113 transmits the table built at 99 to the local controller 31 for the gaming machine 30 , and then returns at 114 to the main loop.
In overall operation, when a person wishes to obtain access to any locked area of a gaming machine 30 , the person first inputs his or her personnel identification information, utilizing the input device 35 . The local controller 35 then communicates this information to the host computer 21 , which compares it with the database 24 to determine which, if any, of the locked areas of the gaming machine 30 the person is entitled to access. If access is authorized for one or more areas, signals are sent back to the gaming machine 30 for controlling corresponding lock mechanisms to unlock those areas. When access is completed and the door is reclosed or the switch or other device is returned to its initial condition, this information will also be communicated back to the host computer, which send signals to can then relock the lock mechanisms.
The gaming machines 30 can also be controlled from the host computer 21 independently of any local access request. Thus, for example, if it is desired to provide a service function on a group of machines, such as drop box emptying or hopper loading, that group of machines is typically roped off and the host computer unlocks the appropriate locking mechanisms so that the service person or team can perform the appropriate service function on all of the machines in the group.
A significant advantage of the system 20 is that it greatly facilitates adjustment of the security system to accommodate changes in personnel or their assigned duties. Thus, if a new employee is hired or an existing employee is terminated or an employee's duties are changed so as to alter the machines or the areas thereof to which access authorization by the employee is required, all that need be done is an appropriate editing of the database 24 and the issuance of a new personal data card 37 . Similarly, if a card is lost, changing of the identification code for the person involved and the re-issuance of a new card is a simple matter. No change in a physical lock mechanism of any gaming machine is required.
While, in the embodiment described above, the database 24 is stored at the host computer 21 , it will be appreciated that it could also be stored at the local controller 31 of each gaming machine 30 . However, in this case, any database changes would have to also be affected at gaming machine. Also, while in the illustrated embodiment only personnel identification data is stored on the personal data card 37 , it would also be possible to store access authorization data on the card 37 so that when the card is input to a card reader at a gaming machine 30 , all areas of that machine to which access is authorized by the card holder could and directly be unlocked without intervention of the host computer.
Various types of input devices 35 have been mentioned above. One possible alternative could be the use of an RF device. In some gaming establishments, it is currently known to have floor personnel to carry a device, such as a hand-held, pocketable computing device of the type sold under PALM trademark, by which they can communicate through an RF link with a similar device in a gaming machine for control of certain functions. It would be possible to utilize such a device as the local controller 31 of a gaming machine, and to have the unit hand-held by establishment personnel serve the function of the input device 35 . Such a device within the gaming machine 30 could communicate with a similar device at a host location over an RF communications link, and could communicate by a wired link, such as an RS232 link, to the individual lock mechanism control/monitor circuits 41 .
The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants' contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
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An apparatus and method affords, to authorized persons, access to one or more lockable areas of one or more gaming machines. Each area includes a door or switch and an associated electrically operable lock mechanism which controls access to the area. Each machine has a local processor communicating with a central host computer and with lock processors for each of its lockable areas. Personnel identification and access authorization data is stored at the host computer. Data may also be stored on personal data cards, respectively assigned to individual persons. A person seeking access inputs identification data at the machine, and the host computer responds with signals to unlock lock mechanisms for areas which the identified person is authorized to access. Each machine monitors the states of all of its locks and doors. A manual override key, disabled when power is on, operates the lock mechanisms when power is off.
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FIELD OF THE INVENTION
The present invention relates to internal combustion engines, and more particularly to a system for controlling the response time of a hydraulic system.
BACKGROUND OF THE INVENTION
Intake valves control entry of an air/fuel mixture into cylinders of an internal combustion engine. Exhaust valves control gases exiting the cylinders of an internal combustion engine. Camshaft lobes (or “cam lobes”) on a camshaft push against the valves to open the valves as the camshaft rotates. Springs on the valves return the valves to a closed position. The timing, duration and degree of the opening, or “valve lift,” of the valves can impact performance.
As the camshaft rotates, the cam lobes open and close the intake and exhaust valves in time with the motion of the piston. There is a direct relationship between the shape of the cam lobes and the way that the engine performs at different speeds and loads. When running at low speeds, the cam lobes should ideally be shaped to open the intake valve as the piston starts moving downward in the intake stroke. Generally, the intake valve should close as the piston reaches the bottom of its stroke and then the exhaust valve opens. The exhaust valve closes as the piston completes the exhaust stroke at the top of its stroke.
At higher engine speeds, however, this configuration for the cam lobes does not work as well. If, for example, the engine is running at 4,000 RPM, the valves are opening and closing 33 times every second. At this speed, the piston is moving very quickly. The air/fuel mixture rushing into the cylinder is also moving very quickly. When the intake valve opens and the piston starts the intake stroke, the air/fuel mixture in the intake runner starts to accelerate and move into the cylinder. By the time that the piston reaches the bottom of its intake stroke, the air/fuel mixture is moving at a high speed. If the intake valve is shut quickly, all of the air/fuel flow stops and does not enter the cylinder. By leaving the intake valve open longer, the momentum of the fast-moving air/fuel mixture continues flowing into the cylinder as the piston starts its compression stroke. The faster the engine turns, the faster the air/fuel mixture moves and the longer the intake valve should stay open. The valve should also be opened to a greater lift value at higher speeds and higher loads. This parameter, called “valve lift,” is governed by the cam lobe profile. A fixed cam lobe profile which always lifts the valve the same amount does not work well at all engine speeds and loads. Fixed cam lobe profiles tend to compromise engine performance at both idle and at high loads.
Variable valve actuation (VVA) technology improves fuel economy, engine efficiency, and/or performance by modifying the valve event lift, timing, and duration as a function of engine operating conditions. Two-step VVA systems enable two discrete valve events on the intake and/or exhaust valves. The engine control module (ECM) selects the optimal valve event profile that is best utilized for each engine operating condition.
An issue in the development and application of the two-step VVA system is the response time variability of a Control Valve (CV) and VVA hydraulic control system. A limited amount of time is available for switching two-step Switching Roller Finger Followers (SRFF) between engaging in one valve event and the corresponding part of the next valve event of another engine cylinder controlled by the same CV. If the CV causes a fluid pressure change in the lifter fluid gallery to occur too soon relative to the critical part of a valve lift curve, the SRFF arm lock pin may only partially engage and then disengage after the valve has started lifting. This unscheduled disengagement is called a “Critical Shift” and may cause the engine valve to drop uncontrollably from the high-lift valve event to the low-lift valve event, or on to the valve seat. After a number of such events, the SRFF arm or the valve may show signs of accelerated wear or damage.
Several factors can affect hydraulic system variation including but not limited to engine oil aeration, duration of engine operation, wear upon the components of the engine, degradation of fluid quality over time, engine temperature, and/or fluid viscosity. These factors increase hydraulic system variations among engines and contribute to the accelerated wear and damage to the engine components.
SUMMARY OF THE INVENTION
A control system and method for a hydraulic system (HS) that controls a fluid supply in an engine includes a timer module determines a response time of the HS to perform at least one of: increasing a pressure of the fluid supply above a predetermined threshold following a state change command and decreasing the pressure of the fluid supply below the predetermined threshold following the state change command. An update module updates the desired time of the HS based on the response time of the HS.
In other features, a pressure sensor senses the pressure of the fluid supply. A control valve (CV) controls the fluid supply. A command module selectively generates and transmits the state change command to the CV when the engine requires a mode change and the engine is operating within a predetermined operating range.
In still other features, the timer module stores a first time when the command module transmits the state change command to the CV and stores a second time when a comparison module detects that the pressure of the fluid supply has at least one of: exceeded the predetermined threshold and fallen below said predetermined threshold. The response time of the HS is based on a difference between the first time and the second time
In still other features the desired time of the HS is indexed in a look-up table that is a function of predetermined engine operating conditions. The update module updates the desired time to equal the response time when the response time exceeds a predetermined time range about the desired time for the predetermined operating condition. Engine operating condition is based on at least one of: engine speed, engine voltage, engine temperature, and fluid temperature.
A control system for controlling a hydraulic system (HS) in an engine includes a pressure sensor that senses pressure of a fluid supply. A control valve (CV) of the HS controls the fluid supply. A control module communicates with the pressure sensor. The control module selectively generates and transmits a state change command to the CV. The control module determines a response time of the HS to at least one of: increase the pressure of the fluid supply above a predetermined threshold following the state change command and decrease the pressure of the fluid supply below the predetermined threshold following the state change command. The control module updates a desired time of the HS based on the response time of the HS.
In other features, the control module selectively generates and transmits the state change command to the CV when the engine requires a mode change and the engine is operating within a predetermined operating range. The control module stores a first time upon generating said state change command and stores a second time upon detecting the pressure of the fluid supply has at least one of: exceeded a predetermined threshold and fallen below the predetermined threshold. The response time of the HS is based on a difference between the first time and the second time. The desired time of the HS is indexed in a look-up table that is a function of predetermined engine operating conditions.
In still other features the control module updates the desired time to equal the response time when the response time exceeds a predetermined time range of said desired time for said engine operating point. Engine operating points are based on at least one of: engine speed, engine voltage, engine temperature, and fluid temperature.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 illustrates an exemplary vehicle including an engine control module (ECM) that communicates with engine sensors and controls the control valve (CV) of a switching roller finger follower (SRFF) mechanism;
FIG. 2 is a three-dimensional view of the SRFF mechanism;
FIG. 3 is a cross-sectional view through the SRFF mechanism;
FIG. 4 is a functional block diagram of a control system for controlling the response time of a hydraulic system according to the present invention;
FIG. 5 is a flow chart illustrating the exemplary steps executed by a control system for controlling the response time of a hydraulic system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term “module” refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
Referring to FIG. 1 , an exemplary vehicle 10 includes an engine 12 , a transmission 14 , and an engine control module (ECM) 16 . The operation of a two-step switching roller finger follower (SRFF) mechanism 28 is controlled by a control valve (CV) 30 that controls a fluid supply (not shown) to a hydraulic lash adjuster 29 . The ECM 16 monitors the operation of the vehicle 10 using various engine sensors. The ECM 16 communicates with a fluid pressure sensor 18 , an engine speed sensor 22 , an engine voltage sensor 24 , and an engine temperature sensor 26 . The fluid pressure sensor 18 generates a signal indicating the fluid pressure within a hydraulic lash adjuster 29 fluid gallery (not shown), and the engine speed sensor 22 generates a signal indicating engine speed (RPM). In various embodiments, the fluid pressure sensor 18 can be positioned in other fixed engine fluid galleries including but not limited to a cam phaser gallery (not shown). The engine voltage sensor 24 generates a signal indicating the operating voltage of the engine electric system, and the engine temperature sensor 26 generates a signal indicating the operating temperature of the engine. The ECM 16 includes memory 20 that stores a look-up table 50 , as depicted in FIG. 4 , for utilization in commanding the CV 30 to switch the operating mode of the SRFF mechanism 28 . In various embodiments, rather than switching among operating modes of the SRFF mechanism 28 , specific operating modes of the SRFF 28 may be commanded to be deactivated from operation. Such embodiments are known in the art and include but are not limited to Valve Deactivation systems.
Referring now to FIGS. 2 and 3 , a switching roller finger follower (SRFF) mechanism 28 is schematically depicted. It is appreciated that the SRFF mechanism 28 is merely exemplary in nature. The SRFF mechanism 28 includes an inner arm assembly 150 and an outer arm assembly 152 which are pivotably joined by a pivoting pin 154 . The inner arm assembly 150 includes a low-lift contact 156 which interfaces with a low-lift cam lobe (not shown) of a camshaft (not shown). The outer arm assembly 152 includes a pair of high-lift contacts 158 a , 158 b as depicted in FIG. 2 , that are configured for contact with a pair of high-lift cams lobes (not shown) of the camshaft and are positioned on either side of the low-lift contact 156 . The inner arm assembly 150 defines a cavity 160 in which a portion of a hydraulic lash adjuster (not shown) can be inserted and about which the inner arm assembly 150 may also pivot.
As depicted in FIG. 3 , a locking pin housing 162 contains locking pins 164 a , 164 b . The locking pins 164 a , 164 b restrict the independent movement of the outer arm assembly 152 from the inner arm assembly 150 about the pivoting pin 154 when the locking pins 164 a , 164 b are in an engaged position. The end faces 165 a , 165 b of locking pins 164 a , 164 b , respectively exist in fluid communication with a source of fluid pressure 166 such as a fluid supply (not shown). The fluid supply is fed from the hydraulic lash adjuster (not shown) to the locking pin housing 162 through a fluid supply hole 168 .
The fluid supply from the hydraulic lash adjuster is controlled by a solenoid or CV, as depicted in FIG. 1 at 30 . At predetermined engine operating ranges, the ECM, as depicted in FIG. 1 at 16 , can cause the CV 30 to switch the fluid supply of the hydraulic lash adjuster from a lower pressure (P 1 ) (not shown) to a higher pressure (P 2 ) (not shown) within the locking pin housing 162 . When fluid pressure (P 2 ) is sufficiently high, the pressure exerted on the locking pins 164 a , 164 b is sufficient to overcome the resistance provided by the springs 170 a , 170 b resulting in the locking pins 164 a , 164 b being extended from their retracted position (shown) to an engaged position (not shown). While the locking pins 164 a , 164 b are in an engaged position, the outer arm assembly 152 is locked to the inner arm assembly 150 and causes the valve (not shown) to follow the high lift cam (not shown) that interfaces with the high-lift contacts 158 a , 158 b.
FIG. 3 depicts the SRFF mechanism 28 configured to operate in low-lift mode. In “normal” (fluid pressure supply at P 1 ) operation, or “low-lift” mode, the low lift cam lobe causes the inner arm assembly 150 to pivot to a second position in accordance with the low-lift cam's prescribed geometry and thereby open a valve (not shown) a first predetermined amount. In various embodiments, a different low mode lift profile may exist for each of the adjacent valves in any given cylinder. The pressure inside the locking pin housing 162 is sufficiently low such that the locking pins 164 a , 165 b remain in the retracted position. The low pressure fluid supply (P 1 ), which enters the inner arm assembly 150 at the cavity 160 and is fed through the hydraulic lash adjuster, is of insufficient pressure to compress the spring 170 and cause the locking pins 164 a , 164 b to engage in order to lock the inner arm assembly 150 for motion dependent on the outer arm assembly 152 . In this condition, the valve (not shown) moves due to the low lift cam (not shown) interfacing with the low-lift contact on the inner arm ( 150 ).
In a high-lift mode (not shown), the ECM 16 instructs the CV 30 to increase the fluid pressure in the locking pin housing 162 to a higher pressure state (P 2 ) sufficiently such that the locking pins 164 a , 164 b compress the springs 170 a , 170 b , respectively and is in an engaged position resulting in the outer arm assembly 152 being locked to the inner, low lift arm 150 and thus prevented to independently pivot about the pivoting pin 154 . The outer arm assembly 152 pivots to a third position in accordance with the high-lift cam lobe geometry causing the valve to open to a second predetermined amount greater than the first predetermined amount. The present invention recognizes that in various embodiments, switching the fluid supply from P 1 to P 2 can cause the locking pins 164 a , 164 b to retract and therefore disengage the outer arm assembly 152 from the inner arm assembly 150 and prevent the valve (not shown) from following the high lift cam (not shown) that interfaces with the high-lift contacts 158 .
Additionally, the present invention envisions further embodiments that may require maintaining a fluid supply at a pressure state of P 2 in which P 2 represents “normal” operation of the SRFF mechanism 28 . In such embodiments, the ECM 16 instructs the CV 30 to decrease the fluid pressure in the locking pin housing 162 to a lower pressure state (P 1 ) in order to engage or disengage the locking pins 164 a , 164 b . The present invention further envisions an embodiment having a single locking pin 164 serve to engage the outer arm assembly 152 .
Referring now to FIG. 4 , a hydraulic control system 32 includes monitoring and transmitting signals received from engine sensors including but not limited to the engine speed sensor 22 , the engine voltage sensor 24 , and the engine temperature sensor 26 . A two-step change flag 34 indicates that the engine requires a change in the lift mode of the SRFF mechanism 28 to maintain appropriate engine operation. A SRFF positioning module 38 monitors the two-step change flag 34 and compares the measured engine operating speed, RPM op , received from the engine speed sensor 22 to a predetermined RPM range. If the value of RPM op is within the predetermined RPM range and the two-step change flag 34 is set, the SRFF positioning module 38 enables the CV command module 40 .
The command module 40 commands the CV 30 to change its state of operation by generating and transmitting a state change command to the CV 30 . In accordance with the state change command, the CV 30 switches the fluid supply provided to the locking pin housing 162 via the hydraulic lash adjuster from a low pressure state (P 1 ) to a higher pressure state (P 2 ). When the command module 40 commands the CV 30 to change its state, a timer module 42 stores the clock time of this command as T a . A comparison module 44 monitors the fluid pressure sensor 18 and compares the pressure within the fluid gallery of the hydraulic lash adjuster 29 to a predetermined pressure threshold. When the comparison module 44 detects a signal from the fluid pressure sensor 18 that the pressure exerted by the fluid supply within the fluid gallery of the hydraulic lash adjuster 29 has exceeded or fallen below a predetermined threshold, the timer module 42 stores this second clock time as T b . The timer module 42 then calculates the time difference between T a and T b as the time response, T act , of the CV 30 to the change of state command.
An update module 46 receives signals from the engine speed sensor 22 , the engine voltage sensor 24 , and the engine temperature sensor 26 indicating the engine operating condition. The update module 46 then retrieves a desired time, T des , of the CV 30 from a lookup table 50 that corresponds to the engine operating condition sensed by the update module 46 . The update module 46 compares the value of T act to T des . If the value of T act has exceeded a predetermined time range about T des , the update module 46 assigns a new value to T des by setting T des equal to T act and stores the new value T des in the look-up table 50 as a function of the engine operating condition.
Referring now to FIG. 5 , the hydraulic control system 32 will be described in further detail. In step 100 , if the engine 12 is turned on, the ECM 16 will be operational and proceed to step 102 . If the engine is not turned on, the ECM 16 will not be operational and the hydraulic control system 32 will not be initiated. In step 102 , the SRFF positioning module 38 determines whether the engine is operating within a predetermined RPM range. The predetermined RPM range is an engine and mechanism specific range. If the engine operating speed, RPM op , is not within the predetermined RPM range, the process ends.
If the RPM op is within the predetermined RPM range, the SRFF positioning module 38 , in step 104 , determines whether a two-step change flag 34 is set indicating that the engine requires a change in the lift mode of SRFF mechanism 28 . If a position change of the SRFF mechanism 28 is not required and the two-step change flag 34 is not set, the process ends. If the two-step change flag 34 is set, the SRFF positioning module 38 enables the command module 40 . In step 106 , the command module 40 generates and transmits a state change command directing the CV 30 to change its state of operation by switching the fluid supply provided to the locking pin housing 162 from either a low pressure state (P 1 ) to a higher pressure state (P 2 ) or from P 2 to P 1 . Additionally in step 106 , the timer module 42 stores the time of the sate change command as a first time, T a .
In step 108 , when the comparison module 44 detects that the pressure exerted by the change in fluid supply has either exceeded or fallen below a predetermined pressure threshold within the locking pin housing 162 , the timer module 42 stores the corresponding time as a second time, T b . In step 110 , the timer module 42 calculates the time difference between T a and T b as T act . The response time of the hydraulic control system 32 is based on T act . In step 112 , the update module 46 determines the engine operating condition by monitoring the engine speed sensor 22 , the engine voltage sensor 24 , and the engine temperature sensor 26 .
In step 114 , the update module 46 retrieves a desired time of the hydraulic control system 32 , T des , from a look-up table 50 that corresponds to engine operating condition in step 112 . In step 116 , the update module 46 compares the value T act to T des . If the update module 46 determines that T act is within a predetermined time range, about T des , the process ends. If the update module 46 determines that T act has exceeded the predetermined time range about T des , the update module 46 assigns a new value to T des by setting T des equal to T act in step 118 . In step 120 , the look-up table 50 stores the value T des as a function of the engine operating point read in step 112 . The process ends in step 122 . Important to note is that the applicability of the present invention is not limited to embodiments that employ SRFF technology but is additionally applicable to valve train technologies that utilize a CV to control the activation of a hydraulic system to regulate valve events. Such valve train technologies include but are not limited to Displacement on Demand technologies and other related VVA technologies.
Additionally, the scope of the invention is not limited to embodiments that solely implement engine component or system control valves. The current invention is applicable to various systems that employ valve control operations including but not limited to transmission torque converters, clutches and brakes.
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.
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A control system and method for a hydraulic system (HS) that controls a fluid supply in an engine includes a timer module determines the response time of the HS to perform at least one of: increasing the pressure of the fluid supply above a predetermined threshold following the state change command and decreasing said pressure of said fluid supply below said predetermined threshold following said state change command. An update module updates the desired time of the HS based on the response time of the HS.
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BACKGROUND OF THE INVENTION
The invention relates to a fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine, having an end remote from the combustion chamber, which end has at least one electrical connection and at least one return connection.
The German laid-open specification DE 31 05 685 A1 discloses a liquid-cooled fuel injection nozzle having a common connection nipple for the discharge of leakage oil and the return of coolant. The German laid-open specification DE 10 2006 040 248 A1 discloses a fuel injection device for a multi-cylinder internal combustion engine having a housing which has two high-pressure connections.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a fuel injection device which is of simple construction and can be produced cheaply.
The object is achieved, in the case of a fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine, having an end remote from the combustion chamber, which end has at least one electrical connection and at least one return connection, in that the return connection and the electrical connection are integrated into a common connection body. According to an essential aspect of the invention, both the return connection and also the electrical connection run through the common connection body. As a result of the combination of the two connections in the common connection body, in particular in the case of longitudinally installed in-line engines, the available installation space under an engine hood of a motor vehicle can be better utilized. Furthermore, by means of the connection body according to the invention, increased demands with regard to pedestrian protection can be more effectively fulfilled. Finally, as a result of the common connection body for the two connections, additional connection pieces can be dispensed with.
A preferred exemplary embodiment of the fuel injection device is characterized in that the return connection and the electrical connection run through the common connection body. The common connection body preferably surrounds the two connections such that injuries to a pedestrian by the connections can be reliably prevented. Furthermore, the structural height of that end of the fuel injection device which is remote from the combustion chamber can be reduced as a result of the common connection body.
A further preferred exemplary embodiment of the fuel injection device is characterized in that the return connection and the electrical connection are partially extrusion-coated with plastic material. The return connection is preferably extrusion-coated with the same plastic material as that used for the extrusion coating of electrical connections.
A further preferred exemplary embodiment of the fuel injection device is characterized in that the fuel injection device comprises a magnet assembly which is at least partially extrusion-coated with plastic material together with the return connection and the electrical connection. The magnet assembly comprises for example a magnet actuator which interacts in a known way with a magnet coil to which the electrical connection is assigned.
A further preferred exemplary embodiment of the fuel injection device is characterized in that the return connection runs through a support plate which constitutes a closure on that end of the fuel injection device which is remote from the combustion chamber. The support plate serves preferably to support a guide pin for the magnet armature of the magnet assembly in the axial direction on that end of the fuel injection device which is remote from the combustion chamber. The support plate may be fully or partially extrusion-coated with plastic material.
A further preferred exemplary embodiment of the fuel injection device is characterized in that, radially outside an inner support point of the support plate, at least one return duct extends from a return chamber in the fuel injection device. The guide pin described above may be supported on the inner support point. The return duct serves to discharge, for example, leakage and/or a cooling medium in the form of fuel at low pressure from the interior of the fuel injection device. The return duct may be joined to a fuel storage tank outside the fuel injection device.
A further preferred exemplary embodiment of the fuel injection device is characterized in that, radially outside an inner support point of the support plate, a plurality of return ducts extend from a return chamber in the fuel injection device, which return ducts open into a central return joining duct. In the common connection body, the return may have, viewed in longitudinal section, for example the shape of an upsilon with two limbs which extend from the return chamber in the interior of the fuel injection device and which open into the central return joining duct.
A further preferred exemplary embodiment of the fuel injection device is characterized in that a return connection duct which runs perpendicular to a longitudinal direction of the fuel injection device extends from the return duct or from the return joining duct. The return is of substantially L-shaped design in the common connection body.
A further preferred exemplary embodiment of the fuel injection device is characterized in that two return connection ducts which run perpendicular to a longitudinal direction of the fuel injection device extend from the return duct or from the return joining duct. The return is of substantially T-shaped design in the common connection body.
A further preferred exemplary embodiment of the fuel injection device is characterized in that, at the inner support point, a guide pin and/or a spring device are/is supported at the inside on the support plate. The spring device comprises for example a helical compression spring by means of which the magnet armature of the magnet assembly is preloaded in the direction of the combustion chamber. The spring device may furthermore comprise a plate spring which exerts a preload force on a magnet actuator.
Further advantages, features and details of the invention will emerge from the following description, which describes an exemplary embodiment in detail with reference to the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing:
FIG. 1 shows a highly simplified illustration of a detail of a fuel injection system having four fuel injection devices connected in series;
FIG. 2 shows an enlarged and more detailed illustration of that end of one of the fuel injection devices from FIG. 1 which is remote from the combustion chamber, in longitudinal section, and
FIG. 3 shows a longitudinal section, rotated through 90°, of that end of the fuel injection device from FIG. 2 which is remote from the combustion chamber.
DETAILED DESCRIPTION
Four fuel injection devices 1 to 4 connected in series are illustrated in highly simplified form in FIG. 1 . The fuel injection devices 1 to 4 comprise in each case an end 5 which is close to the combustion chamber and from which fuel at high pressure is injected into associated combustion chambers of an internal combustion engine. The fuel injection devices 1 to 4 , which are also referred to as fuel injectors, also have in each case one end 6 remote from the combustion chamber, which end 6 is connected via a return connection 40 to a return.
The return connections of the fuel injection devices 1 to 3 are designed in each case as a T-piece 11 , 12 , 13 . The return connection of the fuel injection device 4 is designed as an L-piece 14 . The two T-pieces 12 and 13 are joined to one another via a joining line 15 . The T-piece is joined via a further joining line 17 to the L-piece 14 . The two T-pieces 11 and 12 are joined to one another via a joining line 18 . Furthermore, a joining line 19 extends from the T-piece 11 to a return collecting chamber indicated by an arrow 16 .
The fuel injection device only partially illustrated in FIG. 1 is designed preferably for a multi-cylinder internal combustion engine, preferably an auto-ignition internal combustion engine, of a motor vehicle. The fuel injection device comprises, aside from the illustrated fuel injection devices 1 to 4 , at least one high-pressure pump by means of which fuel is delivered at high pressure.
Each cylinder of the internal combustion engine is assigned one of the fuel injection devices 1 to 4 , which are also referred to as injectors and through which the fuel can be injected into the combustion chamber of the associated cylinder. The highly pressurized fuel is supplied to the fuel injection devices 1 to 4 via fuel high-pressure lines. The actuation of the fuel injection devices 1 to 4 is realized preferably electrically via electrical connection lines.
In FIGS. 2 and 3 , that end 6 of the fuel injection device 1 which is remote from the combustion chamber is illustrated on an enlarged scale in two different longitudinal sectional views. The fuel injection device 1 comprises a housing body 20 which may be of single-part or multi-part design. In that end of the housing body 20 which is remote from the combustion chamber, a magnet assembly 22 is accommodated in a return pressure chamber 24 .
The magnet assembly 22 comprises a magnet actuator 25 with a magnet coil 26 which interacts with a magnet armature 27 . The magnet armature 27 is guided by means of a guide pin 28 such that it can move away from the magnet coil 26 and towards the magnet coil 26 . The guide pin 28 is supported on a support plate 30 which delimits the return pressure chamber 24 in the axial direction. The return pressure chamber 24 is delimited in the radial direction by the housing body 20 .
The magnet armature 27 is preloaded away from the magnet coil 26 by a helical compression spring 31 through which the guide pin 28 extends. The magnet actuator 25 with the magnet coil 26 is preloaded away from the support plate 30 by a plate spring 32 and is actuated via an electrical connection 33 .
As can be seen in FIG. 3 , two electrical connection elements 35 , 36 extend from the magnet coil 26 of the magnet assembly 22 , which connection elements extend through an electrical connection piece 34 into a connection body 60 which is formed from plastic material 62 in which that end 6 of the fuel injection device 1 which is remote from the combustion chamber is extrusion-coated. It can be seen in FIG. 2 that the connection element 35 , at its end, extends perpendicular to the longitudinal direction of the fuel injection device 1 .
Two return ducts 41 , 42 extend from the return chamber 24 , which return ducts open into a common return joining duct 44 of a return connection 40 . The return ducts 41 , 42 extend, radially outside a support point 45 for the guide pin 28 , through the support plate 30 in such a way that, together with the return joining duct 44 , they form in longitudinal section an upsilon which is upside-down in FIG. 2 .
The return joining duct 44 opens at its end remote from the combustion chamber into the connection body 60 through which the two electrical connection elements 35 and 36 also extend. Two transversely running return connection ducts 51 , 52 , in the form of line pieces in the illustrated example, extend through the plastic material 62 which forms the connection body 60 from that end of the return joining duct 44 which is remote from the combustion chamber. Connected to the return connection duct 51 is the joining line 18 . The exemplary embodiment illustrated in FIG. 3 , with the two return connection ducts 51 , 52 , constitutes a T-piece. Alternatively, an L-piece may be analogously formed by means of only one of the return connection ducts 51 , 52 .
According to an essential aspect of the invention, the return connection 40 is integrated directly into the magnet group extrusion coating. For this purpose, a return connection piece may be welded to the support plate and subsequently extrusion-coated with plastic material. The invention also encompasses an embodiment composed entirely of plastic, wherein the connection piece, for example in the form of a T-piece or L-piece, is plugged into the support plate 30 and sealed by means of an O-ring and subsequently extrusion-coated. Furthermore, the return connection may be integrated into an extrusion-coating die by means of which that end of the fuel injection device which is remote from the combustion chamber is extrusion-coated.
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The invention relates to a fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine, comprising an end ( 6 ) that is located at a distance from the combustion chamber and has at least one electric connection ( 33 ) and at least one return flow connection ( 40 ). In order to create a fuel injection device ( 1 ) that has a simple design and can be produced cost-effectively, the return flow connection ( 40 ) and the electric connection ( 33 ) are integrated in a common connecting member.
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RELATED APPLICATIONS
This application is related to patent applications entitled: ‘Method and Apparatus for Reducing Microprocessor Speed Requirements in Data Acquisition Applications,’ U.S. Ser. No. 09/792,996, filed on Feb. 26, 2001; now U.S. Pat. No. 6,502,789, ‘Method and System for Detecting Fluid Injection from Stationary to Rotating Members,’ U.S. Ser. No. 09/951,790, filed on Sep. 10, 2001; ‘Simultaneous Injection Method and System for a Self-Balancing Rotatable Apparatus,’ U.S. Ser. No. 09/896,763, filed on Jun. 29, 2001 ; now U.S. Pat. No. 6,532,421, ‘Energy-Based Thresholds Applied to Dynamic Balancing,’ U.S. Ser. No. 09/951,798, filed on Sep. 10, 2001; ‘Dynamic Correlation Extension for a Self-Balancing Rotatable Apparatus’ U.S. Ser. No. 09/951,932, filed on Sep. 10, 2001; ‘Continuous Flow Method and System for Placement of Balancing Fluid on a Rotating Device Requiring Dynamic Balancing’, U.S. Ser. No. 10/001,006, filed on Nov. 15, 2001; ‘Dynamic Balancing Application Mass Placement’, U.S. Ser. No. 10/001,090, filed on Nov. 15, 2001; ‘Fixed-Bandwidth Correlation Window Method and System for a Self-Balancing Rotatable Apparatus,’ U.S. Ser. No. 09/999,594, filed on Nov. 15, 2001; ‘Supervisory Method and System for Improved Control Model Updates Applied to Dynamic Balancing,’ U.S. Ser. No. 10/011,218, filed on Nov. 15, 2001; ‘Data Manipulation Method and System for a Self-Balancing Rotatable Apparatus,’ U.S. Ser. No. 10/000,882, filed on Nov. 15, 2001; ‘Resonance Identification Extension for a Self-Balancing Rotatable Apparatus,’ U.S. Ser. No. 10/001,098, filed on Nov. 15, 2001, now U.S. Pat. No. 6,546,354.
TECHNICAL FIELD
The present invention relates generally to rotatable members that are able to achieve balanced conditions throughout a range of rotational speeds. The present invention also relates to methods and systems for dynamically balancing rotatable members through the continual determination of out-of-balance forces and motion to thereby take corresponding counter balancing action. The present invention additionally relates to methods and systems in which inertial masses are actively placed within a rotating body in order to cancel rotational imbalances associated with the rotating body thereon. The present invention additionally relates to methods and system for dynamic balancing utilizing concurrent control actuator actions.
BACKGROUND OF THE INVENTION
Mass unbalance in rotating machinery leads to machine vibrations that are synchronous with the rotational speed. These vibrations can lead to excessive wear and to unacceptable levels of noise.
It is a common practice to balance a rotatable body by adjusting a distribution of moveable, inertial masses attached to the body. This state of balance may remain until there is a disturbance to the system. A tire, for instance, can be balanced once by applying weights to it. This balanced condition will remain until the tire hits a very big bump or the weights are removed. However, certain types of bodies that have been balanced in this fashion will generally remain in balance only for a limited range of rotational velocities. A centrifuge for fluid extraction, however, can change the amount of balance as more fluid is extracted.
Many machines are also configured as freestanding spring mass systems in which different components thereof pass through resonance ranges during which the machine may become out of balance. Additionally, such machines may include a rotating body loosely coupled to the end of a flexible shaft rather than fixed to the shaft as in the case of a tire. Thus moments about a bearing shaft may also be created merely by the weight of the shaft. A flexible shaft rotating at speeds above half of its first critical speed can generally assume significant deformations, which add to the imbalance. This often poses problems in the operation of large turbines and turbo generators.
Machines of this kind usually operate above their first critical speed. As a consequence, machines that are initially balanced at relatively low speeds may tend to vibrate excessively as they approach full operating speed. Additionally, if one balances to an acceptable level rather than to a perfect condition (which is difficult to measure), the small remaining out-of-balance will progressively apply greater force as the speed increases. This increase in force is due to the fact that F is proportional to rω 2 , (where F is the out of balance force, r is the radius of the rotating body and ω is its rotational speed).
The mass unbalance distributed along the length of a rotating body gives rise to a rotating force vector at each of the bearings that support the body. In general, the force vectors at respective bearings are not in phase. At each bearing, the rotating force vector may be opposed by a rotating reaction force, which can be transmitted to the bearing supports as noise and vibration. The purpose of active, dynamic balancing is to shift an inertial mass to the appropriate radial eccentricity and angular position for canceling the net unbalance. At the appropriate radial and angular distribution, the inertial mass can generate a rotating centrifugal force vector equal in magnitude and phase to the reaction force referred to above.
Many different types of balancing schemes are known to those skilled in the art. When rotatable objects are not in perfect balance, nonsymmetrical mass distribution creates out-of-balance forces because of the centrifugal forces that result from rotation of the object. Although rotatable objects find use in many different applications, one particular application is a rotating drum of a washing machine.
U.S. Pat. No. 5,561,993, which was issued to Elgersma et al. on Oct. 22, 1996, and is incorporated herein by reference, discloses a self-balancing rotatable apparatus. Elgersma et al. disclosed a method and system for measuring forces and motion via accelerations at various locations in a system. The forces and moments were balanced through the use of a matrix manipulation technique for determining appropriate counterbalance forces located at two axial positions of the rotatable member. The method and system described in Elgersma et al. accounted for possible accelerations of a machine, such as a washing machine, which could not otherwise be accomplished if the motion of the machine were not measured. Such a method and system was operable in association with machines not rigidly attached to immovable objects, such as concrete floors. The algorithm disclosed by Elgersma et al. permitted counterbalance forces to be calculated even when a washing machine is located on a flexible or mobile floor structure combined with carpet and padding between the washing machine and a rigid support structure.
U.S. Pat. No. 5,561,993 thus described a dynamic balance control algorithm for balancing a centrifuge for fluid extraction. To accomplish such balance control, balance control actions may place mass at the periphery of axial control planes on the centrifuge. Sensor measurements may be used to assess the immediate balance conditions. In assessing the balance conditions, measurement thresholds may be established to direct the course of balance control. Related sensor responses to balance control actions may be modeled to determine the specific future control actions. The control actions may require multiple control actuators; generally one per axial control plane, although multiple actuators at multiple control planes may emulate additional virtual control planes. The actuators may be actuated independently or concurrently. The advantage to concurrent actuation is reduced time to place the corrective mass and a smoother control trajectory to the balanced state.
With concurrent actuation, it would be ideal if concurrent corrective mass placement actions could be placed continuously and in constant proportion. An actuation system based on the placement of mass on a rotating apparatus from its stationary surroundings, however, does not permit the continuous placement of mass at any desired proportion. A limited amount of mass can be placed at a specific location only once per revolution, and the actuator action is a step action with a minimum resolution. Thus, a different and unique approach must be utilized to overcome these problems, one in which a desired control action is achieved through discretized proportions that closely represent the ideal continuous control action. Additionally, because of the discrete nature of the control actions (i.e., step actions), one must be concerned that an applied set of step actions does not exceed the threshold set for establishing balanced operations. If they do exceed this threshold, a risk may be incurred of jumping directly through the balanced condition and from one unbalanced state to another.
Based on the foregoing, it can be appreciated that a method and system, and program product implementations thereof, are required to coordinate the concurrent multi-actuator control action in order to accomplish as smooth as possible transition of mass to the control planes of the centrifuge and to ensure incremental control actions have the needed resolution to achieve balanced operation. The invention disclosed herein thus addresses these needs and the related concerns.
BRIEF SUMMARY OF THE INVENTION
The following summary of the invention is provided to facilitate an understanding of some of the innovative features unique to the present invention and is not intended to be a full description. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
It is one aspect of the present invention to provide methods and systems in which rotatable members can achieve balanced conditions throughout a range of rotational speeds.
It is another aspect of the present invention to provide methods and systems for dynamically balancing rotatable members through the continual determination of out-of-balance forces and motion to thereby take corresponding counter balancing action.
It is yet another aspect of the present invention to provide methods and system for dynamic balancing utilizing concurrent control actuator actions.
It is still another aspect of the present invention to provide methods and systems for coordinating discrete concurrent control actuator actions in order to accomplish as smooth as possible transition to a more balanced condition and to ensure incremental control actions have the needed resolution to achieve balanced operation.
In accordance with various aspects of the present invention, methods and systems are disclosed herein for dynamic balancing of a rotating system utilizing coordinated and limited concurrent balance control actuator actions. Control actions place mass at the periphery of axial control planes of the rotating apparatus. Sensor measurements are used to assess the immediate balance conditions. In assessing the balance conditions, measurement thresholds can be established to direct the course of balance control. Related sensor responses to balance control actions are modeled to determine the specific future control actions. The control actions require multiple control actuators, at least one per axial control plane. The actuators are actuated concurrently in order to reduce time to place the corrective mass and provide a smooth transition to the balanced state. With actuator configurations that do not provide for corrective mass to be placed continuously or in constant proportion, the desired control action is achieved through discretized proportions that closely represent the continuous and proportionate control action. The discrete control actions (i.e., step actions) are limited so as to not exceed the thresholds set for establishing balanced operations.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
FIG. 1 depicts a plot of a non-linear system, in accordance with preferred embodiments of the,present invention;
FIG. 2 illustrates a graphical representation of a nonlinear system and the effect of system noise with which the present invention must be concerned;
FIG. 3 depicts a schematic representation of a washing machine, which may be adapted for use in association with the present invention;
FIG. 4 is a spring and mass illustration depicting the manner in which a nonrigid washing machine can behave if mounted on nonrigid structures;
FIG. 5 depicts a three-dimensional schematic representation of the forces and critical lengths along an axis of rotation, which has been extended along a length of the shaft and through a length of the drum;
FIGS. 6 and 7 depict a graphical representation of a shaft with measured forces and accelerations; and
FIG. 8 illustrates a table of a simultaneous dual-actuator algorithm implementation, in accordance with preferred embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate embodiments of the present invention and are not intended to limit the scope of the invention.
The present invention is generally an improvement to the invention disclosed in U.S. Pat. No. 5,561,993. The basic configuration and concepts explained in U.S. Pat. No. 5,561,993 are disclosed herein but in no way limit the scope of the invention described and claimed herein. Features revealed in U.S. Pat. No. 5,561,993 are presented herein for illustrative purposes only, in order to explain the foundation upon which the present invention has been derived. Those skilled in the art can appreciate that such features, including figure, text, descriptions, equations and tables thereof do not limit the scope of the present invention.
FIG. 1 depicts a plot of a non-linear system 1 , in accordance with preferred embodiments of the present invention. Given a very simple (e.g., one-dimensional) non-linear system, such as the non-linear system in FIG. 1, the system can be balanced when the sensor measurement, f(m), is driven to zero. The objective of such a system is to find a value for a counterbalance Δm, such that the sensor measurement f(m) is driven to zero, i.e., f(m)=0. Utilizing a Taylor's series expansion in the vicinity of the anticipated operating range and neglecting second order and higher terms, results in a linear model of the form y=b+mx. The linear model can be written to reflect the example illustrated in FIG. 1, where several possible line estimates are shown; equation 1 expresses this relationship. f ( m next ) ≈ f ( m aftertest ) + ( ∂ f ( m ) ∂ m ) · ( m next - m aftertest ) ( 1 )
Those skilled in the art can appreciate that f(m next ) represents the desired sensor measurement. In addition, f(m aftertest ) can represent the sensor measurement after a test action or a prior balance-control action. The variable m generally represents the out-of-balance in the system. For example, the variable m aftertest generally represents the out-of-balance after a test action (Δm test ), and the change in m, (i.e., Δm=m next −m aftertest ), is the counterbalance required to achieve a desired sensor measurement, (f(m next )=0). The control action involves moving in the direction of the estimated counterbalance and updating the system model and the required counterbalance estimate as control progresses. Those skilled in the art can appreciate that this control implementation of equation 1 represents the well-known Newton Raphson iteration method.
Since the objective is to find f(m next )=0, the general form of the equation reduces to: m next = m aftertest - [ ∂ f ( m ) ∂ m ] - 1 · f ( m aftertest ) ( 2 )
where m next is the solution or system out of balance needed to make f(m next )=0 or to drive the sensor measurement to zero. Thus, the estimated mass change Δm cb generally required for counterbalance action is illustrated in equation 3. Δ m cb = m next - m aftertest = - f ( m aftertest ) / ( ∂ f m ( m aftertest ) ) ( 3 )
The partial derivative, or slope of the sensor function, can be found by perturbing the system. This may be generally illustrated in equation 4, which represents the change in sensor measurements due to a test action (Δm test =m aftertest −m beforetest ). ∂ f m ( m aftertest ) = f ( m aftertest ) - f ( m beforetest ) m aftertest - m beforetest ( 4 )
Combining equations 3 and 4 may result in the generalized form shown in equation 5, which equation is generally expressed in an expanded notion of multiple inputs and outputs. [ f ( m aftertest ) ] = - [ ∂ f ( m ) ∂ m ] · [ Δ m solution ] ( 5 )
Regarding the linear models and associated slope calculation in FIG. 1, it can be appreciated that a change in the mass may result in a change in the system, and the system itself may be nonlinear; thus, the linear model used to determine the next counterbalance may have significant error. Therefore, when applying the Newton Raphson iteration to a process, certain requirements should be followed. First, the initial approximation should be sufficiently accurate to result in subsequent operation near the desired solution and the measurement f(m) being smooth, nearly linear and single-valued in the vicinity of the anticipated operation. Additionally, because higher derivatives are neglected in this type of approximation, the higher derivatives should be small, so as to avoid convergence problems.
Lastly, in applications of the Newton Raphson iteration, only one solution of mass Δm cb should exist for the sensor measurement being equal to zero. This means there is only one root. Even after following the above requirements, system noise may be a concern. In the hypothetical illustration of FIG. 2, a larger initial test action, which changes the system to point C, is preferable to the one that changes it to point B. This is evidenced by comparing the slopes of lines 22 , 24 and 26 , which result from the various test mass perturbations depicted in FIG. 2 . The difference between the before and after test measurement should be large enough to obtain a good approximation of the slope of the function and ensure that the resulting change in the measurement dominates the changes due to system noise.
FIG. 3 depicts a schematic representation of a washing machine 81 , which may be adapted for use in association with the present invention. Those skilled in the art can appreciate that the present invention may be implemented within a rotating device or rotating system, such as, for example, washing machine 81 . Those skilled in the art can further appreciate, however, that other types of rotatable systems or rotating devices may be utilized in accordance with the present invention. Note that as utilized herein, the terms “rotating system,” “rotating device,” “rotating apparatus,” “rotatable apparatus,” “rotatable system,” or “rotatable device” may be utilized interchangeably. The methods and systems of the present invention may be implemented to balance rotating systems, rotating devices or rotating members thereof. Examples of such rotating devices or rotating systems include washing appliances, such as washing machines, dishwashers, circuit board cleaners, and so forth.
In the example of FIG. 3 the basic mechanism of dynamic balancing involves counter balancing the out-of-balance load by injecting water into a plurality of cups placed at front and back axial planes, identified by reference numbers 82 and 80 in FIG. 3, of the rotatable drum. Although the terms “test mass” or “mass” may be used to describe the preferred embodiment fluid mass, those skilled in the art can appreciate that such a mass may be comprised of many different materials, and the invention is not limited to fluid-based injection for placing mass.
FIG. 3 thus schematically illustrates a washing machine 81 comprising a frame 50 , a shaft 52 and a rotatable drum 54 . Shaft 52 may be attached to rotatable drum 54 . These two components can be attached to a rotor or pulley 56 of a motor drive. Frame 50 can provide support for a bearing housing 58 in which bearings, 60 and 62 , are generally supported. A housing mount 64 can support bearing housing 58 . A plurality of sensors identified by the reference numeral 70 is illustrated at location between the housing mount and the bearing housing in FIG. 3 . These sensors are described in greater detail below. Beneath frame 50 are generally shown a carpet and pad 74 , a plywood support member 76 and a plurality of joists 78 . The representation shown in FIG. 3 illustrates a typical application of a horizontal washing machine in a residential housing environment. Those skilled in the art can appreciate that FIG. 3 is presented for illustrative purposes only and that a variety of washing machine configurations and other rotating devices not illustrated herein may be utilized to implement varying embodiments of the present invention.
With continued reference to FIG. 3, the rotatable drum 54 may be shown having a plurality of schematically illustrated back cups 80 and front cups 82 . Both the front and back cups may be disposed at axial ends of the rotatable drum 54 and, although not shown in FIG. 3, both the front and back cups can comprise a plurality of cups dispersed around the periphery of the drum. A quantity of water can be injected into the cups from a stationary control valve supplied with water, such as those identified by reference numerals 90 and 92 .
Some balancing systems assume the machine may be attached rigidly to an immovable object or footing, such as a concrete floor. In many practical residential housing applications, however, the machine is not rigidly attached to an immovable object and, instead, may be associated with a plurality of flexible members. For example, FIG. 4, depicts a schematic representation of a type of arrangement usually encountered in washing machine applications, showing a spring and mass illustration of the manner in which a nonrigid washing machine can behave if mounted on nonrigid structures.
The behavior of frame 50 in relation to footing 79 can be described as a spring representing frame 50 and floor 76 and having a spring constant K 1 . The relationship between a tub 53 (not shown in FIG. 3) surrounding the rotatable drum 54 and frame 50 can be described by a spring constant K 2 . A spring constant K 3 represents the relationship between bearing housing 58 and housing mount 64 , and frame 50 in FIG. 3 . Lastly, FIG. 4 illustrates a spring constant K 4 , which represents the bending of shaft 52 , along with rotatable members 54 and 56 .
Although only represented by boxes in FIG. 4, the schematic illustration depicts a multitude of mass-spring subsystems that define the relationships among major components of the overall system. One purpose for illustrating FIG. 4 is to demonstrate that the relationships among these components are not rigid and, as a result, can permit motion, resulting in accelerations, to occur in response to forces exerted on the various components. Therefore, if the system is not rigid and only forces are measured by the sensors 70 shown in FIG. 3, accurate counterbalance determinations would be extremely difficult, if not impossible, to make.
FIG. 5 illustrates a three-dimensional schematic representation of the forces and critical lengths along the axis of rotation, which has been extended along the length of the shaft and through the length of the drum. Force sensors may be mounted to measure the force transmitted between housing mount 64 and bearing housing 58 , as illustrated in FIG. 3 . The basic concept of dynamic balancing stipulates that vector forces at the front and back cups may represent an out-of-balance condition. Referring to FIG. 5, the system may be provided with a mechanism for sensing a first force F backsensor at a first location 100 of the axis of rotation and a second mechanism for measuring a second force F frontsensor at a second location 102 of the axis of rotation. It should be understood that both the first and second forces shown in FIG. 5 are likely to be determined from a plurality of force sensors arranged so that the resultant force vectors along multiple axes of the system, can be determined at each of the first and second locations, 100 and 102 , of the axis of rotation.
If a washing machine or similar apparatus with a rotating member is rigidly attached to an unmovable object, such as a concrete floor, in such a way that movement of the machine is prevented, a mere force and moment analysis based on forces and moment arms shown in FIG. 5 would be appropriate and, thus, yield sufficient information to allow counterbalance forces to be implemented in a manner that would achieve a balance of a rotating drum 54 . As discussed above in association with FIGS. 3 and 4, however, it is not practical to expect a machine of this type to be installed and operate without motion being experienced by the various portions of the machine. Therefore, it may be beneficial to measure motion relative to a footing or inertial space (e.g., acceleration) and account for it in the analysis of forces.
FIGS. 6 and 7 show the measurement of forces and accelerations in three-dimensional space at various locations along the shaft 52 . Viewing FIGS. 6 and 7 together, it can be seen the forces and accelerations can be measured at two coincident locations on the shaft 52 . It can be appreciated, however, that this coincidence of the first force and the first acceleration or the second force and the second acceleration are not requirements of the present invention. At each of the first and second locations, 100 and 102 , the effects of rotating out-of-balance forces are determined along the horizontal (h) and vertical (v) coordinates. It can be appreciated by those skilled in the art that the coordinates illustrated in FIGS. 6 and 7 represent the fact that the concepts in U.S. Pat. No. 5,561,993 and the present invention, operate with information describing the forces in terms of a magnitude, a fixed direction and an associated rotating drum angle. Similarly, the motion (e.g., accelerations) may also be expressed as a magnitude along a fixed direction with an associated rotating drum angle.
TABLE I
VARIABLE
MEANING
Inputs
Δm front _cb
test counterbalance mass placed in the front plane
(vector)
Δm back _cb
test counterbalance mass placed in the back plane
(vector)
ωback
speed of rotation in (rad/sec) at which the back plane test
counterbalance occurred
ωfront
speed of rotation in (rad/sec) at which the front plane test
counterbalance occurred
R
radius of counterbalance placement (inches)
ω
current speed of rotation
Outputs
f back
back force sensor (lbf) (vector)
f front
front force sensor (lbf) (vector)
a back
back accelerometer sensor (in/sec 2 ) (vector)
a front
front accelerometer sensor (in/sec 2 ) (vector)
Actions
m backplane _cb
estimated backplane counterbalance to drive
sensor readings to zero (vector)
m frontplane _cb
estimated frontplane counterbalance to drive
sensor readings to zero (vector)
For the following discussion, Table I illustrates the inputs and outputs utilized in the multi-input/multi-output condition relating to the invention described in U.S. Pat. No. 5,561,993. In order to find the appropriate solutions for the counterbalance forces described above, measured forces and accelerations should be considered in the balancing of system forces and moments. As described above, the counterbalance masses, forces and accelerations represent magnitudes and angles. Therefore, all variables shown in Table I, except r and ω generally comprise both a magnitude and an angle in polar coordinates which can be converted to complex coordinates. The relationship described in equation 5 above can be rewritten for the multi-input/multi-output case to result in four coupled simultaneous equations, incorporating the effects of perturbations in both front and back planes that could have occurred at rotational speeds slightly different from the current speed. These four relationships are shown below and are identified as equation 6. a back 4 = - ( a back 1 - a back 0 r · ω back 2 · Δ m back_cb ) · r · ω 2 · m backplane_cb - ( a back 3 - a back 2 r · ω front 2 · Δ m front_cb ) · r · ω 2 · m frontplane_cb
a front 4 = - ( a front 1 - a front 0 r · ω back 2 · Δ m back_cb ) · r · ω 2 · m backplane_cb - ( a front 3 - a front 2 r · ω front 2 · Δ m front_cb ) · r · ω 2 · m frontplane_cb
f back 4 = - ( f back 1 - f back 0 r · ω back 2 · Δ m back_cb ) · r · ω 2 · m backplane_cb - ( f back 3 - f back 2 r · ω front 2 · Δ m front_cb ) · r · ω 2 · m frontplane_cb
f front 4 = - ( f front 1 - f front 0 r · ω back 2 · Δ m back_cb ) · r · ω 2 · m backplane_cb - ( f front 3 - f front 2 r · ω front 2 · Δ m front_cb ) · r · ω 2 · m frontplane_cb ( 6 )
The four mathematical relationships illustrated in equation 6 above can be grouped together as a single equation because they are treated as a matrix in the following discussion. The meanings of the subscripts in equation 6 above are identified in Table II.
TABLE I
SUBSCRIPT
MEANING
0
Measurement prior to backplane counter-balance
test mass Δm back _cb
1
Measurement after backplane counter-balance
test mass Δm back _cb
2
Measurement prior to frontplane counter-balance
test mass Δm front _cb
3
Measurement after frontplane counter-balance
test mass Δm front _cb
4
Current sensor measurement
The relationships shown above in equation 6 can be applied to equation 5 in matrix form as: [ a back 4 a front 4 f back 4 f front 4 ] = - [ a back 1 - a back 0 r · ω back 2 Δ m back_cb a back 3 - a back 2 r · ω front 2 Δ m front_cb a front 1 - a front 0 r · ω back 2 Δ m back_cb a front 3 - a front 2 r · ω front 2 Δ m front_cb f back 1 - f back 0 r · ω back 2 Δ m back_cb f back 3 - f back 2 r · ω front 2 Δ m front_cb f front 1 - f front 0 r · ω back 2 Δ m back_cb f front 3 - f front 2 r · ω front 2 Δ m front_cb ] · [ m backplane_cb m frontplane_cb ] · r · ω 2 ( 7 )
where we describe this matrix equation as being in the form b=Ax and A = - ∂ f ( m ) ∂ m = - [ a back 1 - a bac k 0 r · ω back 2 · Δ m back_cb a back 3 - a back 2 r · ω front 2 · Δ m front_cb a front 1 - a front 0 r · ω back 2 · Δ m back_cb a front 3 - a front 2 r · ω front 2 · Δ m front_cb f back 1 - f back 0 r · ω back 2 · Δ m back_cb f back 3 - f back 2 r · ω front 2 · Δ m front_cb f front 1 - f front 0 r · ω back 2 · Δ m back_cb f front 3 - f front 2 r · ω front 2 · Δ m front_cb ] ( 8 )
Equations 6, 7 and 8 depict the mathematical model generally described in U.S. Pat. No. 5,561,993. This mathematical model is formulated, such that the dynamics of the system are divided into two columns based on whether-mass is placed in the front plane (i.e., column 2 ) or the back plane (i.e., column 1 ) of the spinner. The present invention disclosed herein may be used with this control model or like extensions, the more general solution of which allows for the placement of mass in both the front and the back plane simultaneously to formulate the control model and apply control actions. This more general control model solution is briefly discussed and used herein for describing the present invention.
For the more general control model solution, the model developed in equations 5, 6, and 7, take on the general form shown in equation 9. f ( i + 2 ) = - [ f ( i + 1 ) - f ( i ) m ( i + 1 ) - m ( i ) f ( i + 2 ) - f ( i + 1 ) m ( i + 2 ) - m ( i + 1 ) ] [ m ( i + 1 ) - m ( i ) m ( i + 1 ) - m ( i ) m ( i + 2 ) - m ( i + 1 ) m ( i + 2 ) - m ( i + 1 ) ] - 1 [ Δ m back Δ m front ] ( 9 )
In equation 9 above, f(i) represents the i th sensor reading; f(i+2) is equivalent to f(m aftertest ) illustrated in equation 5. Also, m(i) may be a complex vector representing the force at the front and back planes of the rotating apparatus resulting from the i th test action. The equation Δm(i+1)=m(i+1)−m(i) may represent a complex vector of counter balance force or test actions applied to the spinner; each test action formed by injecting simultaneously in the front and the back plane of the spinner. The A matrix (df(m)/dm) obtained from equation 5 is now represented by the relation shown in equation 10. A = - ∂ f ∂ m ( i ) = - [ f ( i + 1 ) - f ( i ) m ( i + 1 ) - m ( i ) f ( i + 2 ) - f ( i + 1 ) m ( i + 2 ) - m ( i + 1 ) ] [ m ( i + 1 ) - m ( i ) m ( i + 1 ) - m ( i ) m ( i + 2 ) - m ( i + 1 ) m ( i + 2 ) - m ( i + 1 ) ] - 1 ( 10 )
Equation 11 below shows the A matrix for the more general control model solution, where 2 control actuators, or control planes, and 4 sensor readings are available, as in the case of equations 6 through 8. A = - [ a back 1 - a back 0 Δ m ( 1 ) cb a back 2 - a back 1 Δ m ( 2 ) cb a front 1 - a front 0 Δ m ( 1 ) cb a front 2 - a front 1 Δ m ( 2 ) cb f back 1 - f back 0 Δ m ( 1 ) cb f back 2 - f back 1 Δ m ( 2 ) cb f front 1 - f front 0 Δ m ( 1 ) cb f front 2 - f front 1 Δ m ( 2 ) cb ] · [ Δ m ( 1 ) back_cb Δ m ( 1 ) cb Δ m ( 1 ) back_cb Δ m ( 2 ) cb Δ m ( 1 ) front_cb Δ m ( 1 ) cb Δ m ( 1 ) front_cb Δ m ( 2 ) cb ] - 1 ( 11 )
The equation relationships shown in equation 9 can be rearranged to solve for the counterbalance forces, Δm back and Δm front , required to bring the system into balance. Utilizing the A matrix from equation 11 for the case of four sensors, a relationship can be expressed through equation 12 as follows: [ Δ m back Δ m front ] = A + · [ a back a front f back f front ] ( 12 )
In a situation such as that described by equation 12 above, four sensor values (i.e., two accelerations and two forces) are generally known from measurements. Two counterbalance forces are unknown. This results in a situation where there are more equations than unknowns as each sensor provides an equation. Conversely, there are only two unknown counterbalance forces for the front and back planes of the drum. This condition describes an over-determined system and a technique generally required to solve for more equations than unknowns in an optimal manner.
A technique for solving equations of this type in a balancing scheme should find a solution that minimizes all of the sensor readings and also minimizes the amount of counterbalance media required to balance the rotating system or rotating device. In other words, the force sensors and the accelerometers should all be driven as close to zero as possible by the selected counterbalances and the total amount of counterbalance media (i.e., fluid or mass) applied be minimized.
Those skilled in the art can appreciate that a mathematical technique which may solve this problem involves computation of the pseudo-inverse of the A matrix (A + ) utilizing a singular value decomposition (SVD) technique. This solution method finds the optimal solution to the inconsistent system represented simply by equation 9. The SVD is one of several techniques that can support the pseudo-inverse calculation for control. It can provide optimal control for both inputs and outputs of the modeled system. Other variations of the components that make up the SVD may be used alone, but would not provide both input and output optimization. This procedure is fully described in U.S. Pat. No. 5,561,993, which is incorporated by reference herein. The SVD technique is well known to those skilled in the art and is described in significant detail in various reference linear algebra textbooks.
After generating the solution to equation 12, it may be necessary to formulate a practical approach to applying the counterbalance mass to the rotating member so as to move as directly as possible toward a more balanced state. An approach to applying counterbalance control actions as part of a balance control scheme is fully described in U.S. Pat. No. 5,561,993, which is incorporated herein, along with extensions for simultaneous control actuator activation, for illustrative and background purposes only. To accomplish balance control, balance control actions may place mass at the periphery of axial control planes on the centrifuge. Sensor measurements may be used to assess the immediate balance conditions through the use of measurement thresholds, established to direct the course of balance control. Measurements of the forces and motions at various locations within the rotatable apparatus are made before and after each control action and may be used to update the control model described by equations 9 through 12. That updated model along with further sensor measurements may be utilized to determine a prediction of the next required counterbalance control action. This process continues until balance condition is achieved (i.e., all sensor values below balance threshold) at full operating speed.
The control actions may require multiple control actuators, generally one per axial control plane, although multiple actuators at multiple control planes may emulate additional virtual control planes. The actuators may be actuated independently or concurrently. The advantage to concurrent actuation is reduced time to place the corrective mass-and a smoother control trajectory to the balanced state.
With concurrent actuation, it would be ideal if these optimal counterbalances, determined by solving the system model in the manner described herein, were completely applied in a continuous fashion and at constant proportion across the multiple actuators, thereby smoothly driving all of the sensors to zero and achieving perfect balance of the rotating member. An actuation system based on placing mass to the rotating apparatus from its stationary surroundings in step-like actions, however, does not allow continuous placement of mass at any constant proportion. For each actuator, a limited amount of mass can be placed at a specific location on the rotating member only once per revolution, and the actuator action is a step action with a minimum resolution. Additionally, because of the discrete nature of the control actions (i.e., step actions), one must be concerned that an applied set of step actions does not exceed the threshold set for establishing balanced operations. If they do exceed this threshold, a risk may be incurred of jumping directly through the balanced condition and from one unbalanced state to another.
Thus, a different and unique approach must be utilized to overcome these problems, one in which a desired control action is achieved through discretized proportions that closely represent the ideal continuous control action. The present invention provides methods and system for coordinating discrete concurrent control actuator actions in order to accomplish as smooth as possible transition to a more balanced condition, and to ensure incremental control actions have the needed resolution to achieve balanced operation.
In the illustrative configuration disclosed herein, counterbalance control actions may be mathematically resolved into mass placement actions for each control plane. The mass placement actions can then be applied simultaneously to a centrifuge (i.e., spinner) that may have a front and back radial plane normal to the axis of rotation and bound by the circumference of the cylinder. The circumference of each plane may be lined with cups to retain mass that is strategically placed across a predetermined range of rotation angles to dynamically create balanced conditions during spinning operations. These cup-lined planes may comprise control planes. For each control plane, the mass is placed via an injector valve mounted on the stationary (i.e., not rotating) part of the system. As the appropriate spinner cups pass the injector valve, mass can be released into the cups. In order to apply the total desired control action, the mass is often injected over a number of revolutions of the rotating device or rotating system.
The desired control action is converted to mass to be placed for the front and back control planes. The mass-placement actuators can each be characterized and appropriate factors applied to determine the amount of mass contributing to the desired control action per actuation. The front and back mass may then be converted to front and back control actuator actions: mass placed per actuation, number of actuations, and angular span of actuation. Thus, a control action may comprise a number of cycles or steps of the control actuator placing incremental amounts of mass over an angular span of the control plane per rotation, located about a desired point-effect location. A system constant may be established that provides a limit for force applied to the control plane across a set of mass placement steps. This force limit can ensure that an applied subset of step actions does not exceed the sensor measurement thresholds establishing balanced operation. This force limit can be associated with a specific mass value, and thereafter converted to a number of control actuator actions, both adjusted for rotational speed. The parameters in equation 13 may be utilized.
Force limit=2 lbf= mrω 2
r =cylinder radius
ω=(RPM×2 π )/60=rotation speed in radians per second
m =(2 lbf)/( rω 2 )=point-mass limit so balance threshold not exceeded
mg =(2×g)/( rω 2 )=point-mass limit weight based on gravity g=386.4 in/sec 2 ( 13)
Both front and back control actuators may place the same or different increments of mass per mass-placement cycle or step, and each can be turned on a different number of cycles or steps in order to achieve the total desired control action. These front and back control actuator actions may occur simultaneously as provided by the enhanced balance control model discussed herein and in accordance with the methods and systems of the present invention. Control actuator actions can be applied in subsets that may not exceed the force limit checks, which are based on balance thresholds. The variables in equation 14 may be utilized.
FlnjNo =Number of front control actuator steps for desired control action,
BlnjNo =Number of back control actuator steps for desired control action,
FThrNo =Number of front control actuator steps in the force-limited set,
BThrNo =Number of back control actuator steps in the force-limited set,
ThrNo=FThrNo
0
+BThrNo
0
=Total number of control actuator steps in the desired force-limited set. ( 14)
It is preferable to step through the control actuator actions FlnjNo and BlnjNo in incremental sets that do not exceed ThrNo, while at the same time closely maintaining the proportion FlnjNo/BlnjNo, or until a new control action is determined necessary by the balance control process.
Given FlnjNo, BlnjNo, the front and back mass-increment per control actuator action, and the parameters of equation 13, we can find the desired FThrNo 0 and BThrNo 0 , and the corresponding ThrNo. After that, FThrNo and BThrNo are updated as discussed herein. The ratios of equation 15 must be considered.
FlnjNo/BlnjNo =Real value that varies from 0 to ∞ as control action conditions change from all control actuator actions in the back to all control actuator action in the front control plane.
FThrNo/ThrNo=Discrete increments of 1/ThrNo ranging in value from 0 to 1 as the partitions of control actuator actions in ThrNo shift from all in the back to all in the front control plane.
BThrNo/ThrNo=Discrete increments of 1/ThrNo ranging in value from 0 to 1 as the partitions of control actuator actions in ThrNo shift from all in the front to all in the back control plane. (15)
Temporarily assume that the later two ratios can take on any positive real value in the established range, versus discrete increments of 1/ThtNo. By simply reassigning some variables, as shown in equation 16, a relationship can be established between FlnjNo/BlnjNo and FThrNo/ThrNo or between FlnjNo/BlnjNo and BThrNo/ThrNo, as shown in equations 17 through 20. y = FlnjNo BlnjNo = Desired proportion to maintain throughout the full control action ( 16 ) x = FThrNo ThrNo = Proportion of front to total actuations in a force - limited set z = BThrNo ThrNo = Proportion of back to total actuations in a force - limited set y = FlnjNo BlnjNo ≈ FThrNo BThrNo = FThrNo ( ThrNo - FThrNo ) = FThrNo ThrNo ( ThrNo - FThrNo ) ThrNo = x ( 1 - x ) ( 17 ) y = FlnjNo BlnjNo ≈ FThrNo BThrNo = ( ThrNo - BThrNo ) BThrNo = ( ThrNo - BThrNo ) ThrNo BThrNo ThrNo = ( 1 - z ) z ( 18 )
Rearranging terms in equations 17 and 18 results in the relations of equations 19 and 20, providing a simple mathematical relation involving both the ratios of equation 15 and the force limits of equation 14. x = y 1 + y ( 19 ) z = 1 1 + y ( 20 )
Consider equation 19 above, such that if the ratio FlnjNo/BlnjNo is provided, then the value of y is known and the value of x can be computed. This value of x, along with the previously determined ThrNo, can then be used with equation 16 to compute FThrNo, which is thereafter subtracted from ThrNo to obtain BThrNo. Recall, however, it was assumed that x could be any real positive value, when in reality x takes on discrete values in increments of 1/ThrNo ranging in value from 0 to 1. To resolve this, simply determine x from the known y value, and then round x to its nearest discrete value, x′, before determining FThrNo and BThrNo.
Once FThrNo and BThrNo are determined from x′, they can be applied against the total desired control action. Given improved balance conditions, this desired control action can be continued by establishing a new value for y, y 1 , that is based on the number of actuator steps remaining in the desired action. From the new y value, y 1 , a new x value, x 1 , can be determined and rounded to the nearest value x 1 ′, as shown in equations 21 and 22. y 1 = ( FlnjNo - FThrNo ) ( BlnjNo - BThrNo ) ( 21 ) x 1 = y 1 1 + y 1 ( 22 ) x 1 ′ = Nearest_Discrete _Value ( x 1 )
leading to the next force-limited set of control actuator actions to be applied against the total desired control action, FThrNo 1 and BThrNo 1 . This evolution of control actuator sets continues until the total control action is accomplished or until a new control action is determined necessary.
FIG. 8 illustrates a table 350 illustrating a simultaneous dual-actuator algorithm implementation, in accordance with preferred embodiments of the present invention. Those skilled in the art can appreciate that table 350 and the values and parameters indicated therein represent merely one example of a multi-actuator algorithm in accordance with preferred embodiments of the present invention. Other algorithmic implementations may also be utilized in accordance with the present invention. Table 350 is based on the illustrative parameters in equation 23.
FlnjNo =22
BlnjNo =4
ThrNo =5 ( 23)
Column 352 represents values for the front control plane of a rotating system. Column 354 represents values for the back control plane of the rotating system. Column 356 represents y values, while columns 358 and 360 respectively represent x and x′ parameters. Column 362 lists FThrNo values, while column 364 represents BThrNo values. Those skilled in the art can appreciate that initially desired actions and threshold-limited actions are designated and thereafter incremented to a “next desired action” and “next force-limited action” until values of 0 are achieved.
The method can be further generalized for the case of more than two control planes with associated control actuators. The variables of equation 14 take on the general form of equation 24.
n =Number of control actuators
lnjNo ( i )=Number of control actuator i steps for desired control action
ThrNo ( i )=Number of control actuator i steps in the force-limited set
ThrNo
=
∑
n
ThrNo
(
i
)
0
=
Total
number
of
actuator
steps
in
desired
force
-
limited
set
(
24
)
The ratios of equation 15 are more generally represented by equation 25. InjNo ∑ j = i + 1 n InjNo ( j ) 25 = Real value that varies from 0 to ∞ as control action conditions change from no control actuator i actions to all control actuator i actions . ( 25 ) ThrNo ( i ) ThrNo - ∑ j = 1 i - 1 ThrNo ( j ) = Discrete value ranging from 0 to 1 as actuator i contribution to remaining force - limited set actuations ranges from nothing to fully contributing .
The reassignment of variables in equation 16 becomes that shown in equation 26 and the relationships of equations 17 and 19 become those of equations 27 and 28. y ( i ) = InjNo ( i ) ∑ j = i + 1 n InjNo ( j ) = Desired proportion to maintain throughout the full control action ( 26 ) x ( i ) = ThrNo ( i ) ThrNo - ∑ j = 1 i - 1 ThrNo ( j ) = Proportion of i to total remaining actions in a force - limited set y ( i ) = InjNo ( i ) ∑ j = i + 1 n InjNo ( j ) ≈ ThrNo ( i ) ∑ j = i + 1 n ThrNo ( j ) = ThrNo ( i ) ( ThrNo - ∑ j = 1 i - 1 ThrNo ( j ) ) - ThrNo ( i ) = ThrNo ( i ) ( ThrNo - ∑ j = 1 i - 1 ThrNo ( j ) ) ( ThrNo - ∑ j = 1 i - 1 ThrNo ( j ) ) - ThrNo ( i ) ( ThrNo - ∑ j = 1 i - 1 ThrNo ( j ) ) = x ( i ) 1 - x ( i ) ( 27 ) x ( i ) = y ( i ) 1 + y ( i ) ( 28 )
Generalizing the method described for equation 19 through 22, the relations of equations 24 through 28 are progressively applied to actuator 1 through n−1. The value of x(i) can be rounded to the nearest increment of 1 / ( ThrNo - ∑ j = 1 i - 1 ThrNo ( j ) )
to obtain x′(i), which is then used in equation 26 to determine ThrNo(i), with ThrNo(n) assigned the remaining actuations in the force-limited set. This is then iterated as control sets are applied against the total control action as described in the earlier simple case.
The embodiments and examples set forth herein are presented to best explain the present invention and its practical application and to thereby enable those skilled in the art to make and utilize the invention. Those skilled in the art, however, will recognize that the foregoing description and examples have been presented for the purpose of illustration and example only. Other variations and modifications of the present invention will be apparent to those of skill in the art, and it is the intent of the appended claims that such variations and modifications be covered. The description as set forth is not intended to be exhaustive or to limit the scope of the invention. For example, those skilled in the art can appreciate that the methods described herein, including mathematical formulations, can be implemented as a program product in the form of varying software modules, routines, and subroutines. Many modifications and variations are possible in light of the above teaching without departing from the spirit and scope of the following claims. It is contemplated that the use of the present invention can involve components having different characteristics. It is intended that the scope of the present invention be defined by the claims appended hereto, giving full cognizance to equivalents in all respects.
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A method and system for dynamically balancing a rotating system based on a plurality of simultaneous and discrete control actions that place mass at predetermined locations within the rotating system so as to achieve balance is disclosed. A balance control algorithm may be utilized to provide a desired control action regarding an amount of mass to be placed, the extent each discrete action contributes, and the location of placement on the rotating system. The control action is broken down into subsets of discrete actuator steps whose whole will accomplish the desired control action. The composition of the actuator step subsets is based on particular ratios and limits and evolve based on the portion of the action already accomplished. A plurality of control actuators is simultaneously activated to deploy the discrete control actuator actions that place mass at predetermined locations within the rotating system. The subsets of discrete control actuator actions can be applied in a manner that most closely resembles a continuous placement of mass so as to smoothly place the rotating system in a balanced state, thereby mechanizing simultaneous and discrete control actuations within the rotating system.
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BACKGROUND
1. Field of the Invention
The present invention relates generally to telephones, and more particularly, to telephones capable of providing a DSL connection.
2. Background of the Invention
DSL (Digital Subscriber Line) service provides customers with high speed access to the Internet and other computer networks. Customers who request DSL service often contact a DSL service provider who then either dispatches a technician to the customer's dwelling to install the equipment necessary to support DSL service, or sends a self-install kit to the customer with instructions that include the necessary installation procedures.
Regardless of exactly how the DSL service installation is performed, one required step of the DSL installation is to provide a filter for every telephone in the dwelling. A filter is required to block unwanted noise generated by DSL signals from interfering with conventional voice telephones.
Generally, local telephone companies provide four wires for each dwelling. Two wires or leads are used for conventional POTS (Plain Old Telephone Service), leaving two remaining wires. It has been observed that most customers place a conventional telephone near the point where DSL service is provided. For example, if DSL service is accessed from a computer placed in a home office, many customers will also have a conventional telephone in the home office as well, and often the conventional telephone will be placed near the computer that is used to access DSL services.
In those instances where a telephone is placed near the access point for DSL services, a splitter is required to split the conventional telephone wires from the DSL wires. The splitter is normally mounted on the wall where the DSL line enters the dwelling. The splitter is used to split the line and thus provide a DSL connection and a telephone connection.
SUMMARY OF THE INVENTION
The present invention is directed to a telephone that provides a DSL connection in addition to functioning as a normal telephone. The telephone includes a removable DSL filter cartridge. The telephone includes a location or place that is designed to receive a filter cartridge. The filter cartridge is designed to fit inside the location provided on the telephone. The filter cartridge includes a first end that electrically connects the filter cartridge to the telephone and a second end that faces outwards. The second end includes a DSL port so that users can plug DSL devices directly into the port. The filter cartridge includes a DSL filter to help eliminate unwanted noise on the telephone line. The filter cartridge assembly is designed to be easily removable.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and advantages of the invention will be realized and attained by the structure and steps particularly pointed out in the written description, the claims and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded isometric view of a preferred embodiment of a telephone in accordance with the present invention.
FIG. 2 is an enlarged view of an end of a preferred embodiment of a filter cartridge in accordance with the present invention.
FIG. 3 is a schematic diagram of a preferred embodiment of a filter cartridge in accordance with the present invention.
FIG. 4 is a schematic diagram of a side view of preferred embodiment of a latch in accordance with the present invention.
FIG. 5 is a schematic diagram of a top view of preferred embodiment of a latch in accordance with the present invention.
FIG. 6 is an exploded isometric view of another embodiment of a telephone in accordance with the present invention.
FIG. 7 is an enlarged isometric view of a portion of a preferred embodiment of a telephone in accordance with the present invention.
FIG. 8 is a schematic diagram of a preferred embodiment of a button in a rest position in accordance with the present invention.
FIG. 9 is a schematic diagram of a preferred embodiment of a button in a deployed position in accordance with the present invention.
FIG. 10 is a schematic diagram of a preferred embodiment of a button in a pressed position in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a preferred embodiment of a telephone 102 in accordance with the present invention. Telephone 102 can be connected to a wall jack 108 and a computer 110 or any device that uses DSL services. Telephone 102 includes a location 104 that is designed to receive a filter cartridge 106 . Location 104 can be placed in any desired part of telephone 102 . Preferably, location 104 is placed at the rear of telephone 102 as shown in FIG. 1 . In another embodiment, location 604 is placed on a side of telephone 602 (see FIG. 6 ).
Referring to FIGS. 1 and 2 , filter cartridge 106 includes a first end 120 that is designed to enter a location 104 of telephone 102 . Filter cartridge 106 also includes a second end 122 that faces in a different direction than first end 120 and second end 122 is preferably exposed when filter cartridge 106 is installed in telephone 102 . Preferably, the substantial remainder of filter cartridge 106 is received in location 104 and is not visible after being installed.
Second end 122 preferably includes two connectors, a line connector 112 and a DSL connector 114 . Line connector 112 is adapted to receive a line 116 that places filter cartridge 106 in communication with wall jack 108 . Likewise, DSL connector 114 is adapted to receive a DSL line 118 that places filter cartridge 106 in communication with a device adapted to receive DSL communications. A computer 110 , is an example of a device that is adapted to receive DSL communications. Computer 110 would likely include a DSL modem or other device that would permit computer 110 to use DSL communications.
FIG. 3 shows a schematic diagram of a preferred embodiment of a filter cartridge 106 . As discussed above, line connector 112 communicates with wall jack 108 (see FIG. 1 ). Generally, an inner pair 306 and an outer pair 308 of leads are available. Most communications services are provided on the inner pair 306 of leads, so conductors 302 that place block 310 in communication with line connector 112 is preferred. However, in some cases, outer leads 308 provide communications services, and outer conductors 304 may be provided to place block 310 in communication with line connector 112 . In another embodiment, both the inner conductors 302 as well as the outer conductors 304 are provided so that, regardless of which pair of leads the communications services are provided, block 310 will be placed in communication with line connector 112 .
Filter cartridge 106 preferably includes a block 310 . Block 310 acts to split an incoming signal from either the inner pair of conductors 302 or the outer pair of conductors 304 or both and place both filter 312 and DSL connector 114 in communication with the incoming signal. DSL connector 114 is designed to permit filter cartridge 106 to communicate with a device that can accept a DSL signal. One example of such a device is a DSL modem. Because DSL modems and other devices that can accept a DSL signal use either the inner or outer pair of leads, it is preferred that both the inner and outer pairs of conductors are provided in DSL conductor 314 disposed between block 310 and DSL connector 114 . In this way, regardless of which pair, either the inner or the outer, of leads is used by the subsequent DSL device or modem, that device or modem will receive a signal from filter cartridge 106 .
Filter 312 is a standard DSL filter and can remove unwanted noise and signals from communicating with an electrical connector 316 or 318 . In a preferred embodiment, a first end 120 of filter cartridge 106 includes an electrical connector 316 that is designed to engage a corresponding electrical connector (not shown) disposed within location 104 . In other embodiments, the electrical connectors of the filter cartridge 106 could be located on any face or surface of the filter cartridge and provisions would be made in telephone 102 to suitably engage those electrical connectors. For example, an electrical connector 318 could be disposed on a side of filter cartridge 106 . Electrical connector 318 could be used as an alternative to electrical conductor 316 or could be used in addition to electrical conductor 316 . Electrical connector 316 and/or 318 permit telephone 102 (see FIG. 1 ) to communicate with filter cartridge 106 and therefore, with wall jack 108 . In this way, conventional telephone service with possible DSL noise removed is provided to telephone 102 .
After filter cartridge 106 has been installed in telephone 102 , second end 122 , which includes a DSL connector 114 , is visible and readily accessible. This arrangement provides a convenient system for providing DSL access. Users can plug DSL devices directly into telephone 102 and do not have to search for inconvenient DSL connectors located in walls, behind furniture, and other hard to reach locations.
Preferably, filter cartridge 106 is designed in a way that makes it easy to remove the filter cartridge 106 from telephone 102 . Many different options and possibilities could be utilized.
FIGS. 4 and 5 show a preferred embodiment of one possible arrangement that can be used to provide easy installation and removal of filter cartridge 106 . Filter cartridge 106 includes a latch 402 that includes a first end 406 and a second end 404 . Preferably, second end 404 of latch 402 is associated with an upper surface 410 of filter cartridge 106 . In an exemplary embodiment, the second end 404 is fixedly attached to upper surface 410 . The first end 406 is disposed opposite second end 404 and preferably extends axially beyond leading edge 412 of the second end 122 of filter cartridge 106 .
Preferably, latch 402 is biased in a direction away from upper surface 410 and latch 402 includes at least one shoulder 408 . Preferably, the bias is achieved by elastic deformation of latch 402 . Preferably, a matching shoulder and void (not shown) is provided in location 104 (see FIG. 1 ) where the void accommodates first end 406 and where the matching shoulder opposes shoulder 408 . When filter cartridge 106 is inserted into location 104 (see FIG. 1 ), latch 402 is initially pressed towards upper surface 410 until latch 402 returns to its biased, raised position when first end 406 enters the void. In this position, shoulder 408 engages a mating shoulder disposed in location 104 and securely retains filter cartridge 106 in position.
To remove filter cartridge 106 , a user presses first end of latch 406 towards upper surface 410 until shoulder 408 clears the mating shoulder disposed in location 104 . Preferably, first end 406 extends beyond the leading edge 412 of second end 122 to facilitate operation of latch 402 . When this occurs, filter cartridge 106 is free and can be easily removed from location 104 .
FIG. 6 shows another embodiment of a telephone 602 . Telephone 602 includes a location 604 that is designed to receive a filter cartridge 606 . Filter cartridge 606 includes a standard DSL filter. In a preferred embodiment, a first end 608 of filter cartridge 606 includes an electrical connector that is designed to engage a corresponding electrical connector (not shown) disposed within location 604 . In other embodiments, the electrical connectors of the filter cartridge 606 could be located on any face or surface of the filter cartridge and provisions would be made in telephone 602 to suitably engage those electrical connectors.
Filter cartridge 606 also has a second end 610 . Second end 610 is designed to be accessible after filter cartridge 606 has been installed in telephone 602 . Second end 610 includes at least one electrical connector. Preferably, second end 610 includes a DSL connector, and in an exemplary embodiment, second end 610 includes a female DSL connector 612 .
After filter cartridge 606 has been installed in telephone 602 , second end 610 , which includes a DSL connector, is visible and readily accessible. This arrangement provides a convenient system for providing DSL access. Users can plug DSL devices directly into telephone 602 and do not have to search for inconvenient DSL connectors located in walls, behind furniture, and other hard to reach locations.
Preferably, filter cartridge 606 is designed in a way that makes it easy to remove the filter cartridge 606 from telephone 602 . Preferably, an ejection system similar to one used for a PCMCIA slot is utilized. Referring to FIGS. 7-10 , the ejection system includes a three position button 702 . Button 702 has a rest position (see FIG. 8 ). From the rest position, when button 702 is pressed, button 702 extends outwards to a deploy position, as shown in FIG. 9 . When button 702 is pressed from the deploy position, filter cartridge 606 is ejected from telephone 602 .
The foregoing disclosure of the preferred embodiments of the present 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 forms disclosed. Many variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.
Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.
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A telephone including a removable DSL filter cartridge is disclosed. The telephone includes a location adapted to receive a filter cartridge. The filter cartridge is designed to fit inside the location provided on the telephone. The filter cartridge includes a first end that electrically connects the filter cartridge to the telephone and a second end that faces outwards. The second end includes a DSL port so that users can plug DSL devices directly into the port. The filter cartridge includes a DSL filter to help eliminate unwanted noise on the telephone line and the filter cartridge is designed to be easily removable.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a Section 371 filing of International Application No. PCT/FR2006/050079 filed Jan. 31, 2006, and published, in French, as International Publication No. WO 2006/090076 A1 on Aug. 31, 2006, and claims priority of French Application No. 0550514 filed on Feb. 24, 2005, all of which applications are hereby incorporated by reference herein, in their entirety.
BACKGROUND ART
The invention relates to a paper having an improved dry strength and its method of fabrication, characterized by the use of a three-component system comprising at least two polymers mainly having cationic fillers and at least one overall anionic polymer. These polymers are combined to exert a synergistic action on the dry strength of this paper.
More precisely, the invention relates to an improved method for fabricating paper and/or cardboard and the like, in which at least three (co)polymers are used to improve the dry strength characteristics during the fabrication of cellulose sheets, respectively:
at least one first agent corresponding to a (co)polymer having a cationic filler density higher than 1 meq/g and having primary amine functions, at least one second agent corresponding to a synthetic organic (co)polymer having a cationic filler density higher than 0.1 meq/g, and at least one third agent corresponding to a (co)polymer having an anionic filler density higher than 0.1 meq/g.
According to the invention, the (co)polymer having primary amine functions is conventionally obtained organic polymer and well known to a person skilled in the art, such as for example—by a Hofmann degradation reaction on a base (co)polymer—or by acidic or basic hydrolysis of a base (co)polymer of polyvinylformamide, and derivatives thereof.
The three-component system can be used successfully for fabricating papers and cardboards, coated paper supports, any type of paper, cardboard and the like requiring improved dry strength.
Ongoing efforts are being made to papers and cardboards which are increasingly strong, particularly for the packaging industry.
The dry strength of the paper is, by definition, the strength of the normally dry sheet. The values of the burst strength and tensile strength conventionally give a measurement of the dry strength of the paper.
The use of water-soluble cationic polymers for improving the strength characteristics of paper is well known. Due to their nature, they can be fixed directly on the anionic cellulose and give it a cationic filler so that in combination with anionic polymers, the latter are fixed on the cellulose fibres, thereby improving the dry strength of the sheet.
The most commonly used cationic polymers are compounds of the cationic starch type, polyamide epichlorhydrin (PAE), polyamide amine epichlorhydrin (PAAE) or cationic polyacrylamides, optionally glyoxalated.
However, the methods described in the prior art using these polymers are not fully satisfactory, particularly concerning the quantities of polymers required and/or the wet strength characteristics obtained, giving rise to process difficulties such as reduction of the sheet to pulp for recycling the dry fragments. The latter drawback is observed in particular when the method described in document US 2004/118540 is implemented.
The burst strength of the cellulose sheets obtained by the use of dry strength agents also meets a number of requirements. It must in particular have no toxicological drawbacks and have good compatibility with the other agents used in the fabrication of the sheet.
It has already been proposed, particularly in patent applications JP 58-60094 (Hamano), JP 04-57992 (Mitsui), US 2004/118540 (Kimberly Clark) to combine, in two-component type systems, polymers having vinyl amine type functions with an anionic polymer, this combination being intended to propose an efficient system for the dry strength of the paper sheet.
BRIEF SUMMARY OF THE INVENTION
The invention relates to a method for fabricating paper characterized by the use of a system that is not a two-component but a three-component system comprising at least two polymers mainly containing cationic fillers and at least one overall anionic polymer, thereby unexpectedly improving the dry strength properties of the paper while being economically less expensive.
The applicant has found and developed an improved method for fabricating a sheet of paper and/or cardboard and the like, which consists, before the formation of the said sheet, in adding to the fibrous suspension, separately or mixed when two agents are compatible, in any order of introduction, at least one or more injection points, at least three dry strength agents respectively:
a first agent corresponding to a (co)polymer having a cationic filler density higher than 1 meq/g and having primary amine functions, a second agent corresponding to a synthetic organic (co)polymer having a cationic filler density higher than 0.1 meq/g, and a third agent corresponding to a (co)polymer having an anionic filler density higher than 0.1 meq/g.
For greater clarity, in the rest of the description, in the examples and in the claims, the (co)polymer having a cationic filler density higher than 1 meq/g and having primary amine functions is designated “first agent” or “polyvinylamine” although it may be introduced into the fibrous suspension after the third agent called “third agent” and vice versa. The same applies to the “second agent”.
The second agent is a synthetic organic (co)polymer resulting from a free radical polymerization process.
As emphasized previously, the invention relates to an improved method which consists, during the very preparation of the paper, in incorporating in the fibrous suspension or mass or paper pulp, as dry strength agents, in any order whatsoever:
0.01 to 2% by weight of active polymer matter compared to the dry weight of the fibrous suspension, at least one (co)polymer having a cationic filler density higher than 1 meq/g and having primary amine functions, 0.01 to 2% by weight of active polymer matter compared to the dry weight of the fibrous suspension, of at least one synthetic organic (co)polymer having a cationic filler density higher than 0.1 meq/g, and 0.01 to 2% by weight of active polymer matter compared to the dry weight of the fibrous suspension, of at least one (co)polymer having an anionic filler density higher than 0.1 meq/g.
Very unexpectedly, the inventive method serves to obtain performance levels unequalled, with similar proportions, for dry strength in paper applications.
In particular, the inventive method serves to obtain very high burst strength and tensile strength without any negative side effects.
DETAILED DESCRIPTION
A. The “First” Dry Strength Agent: the (Co)Polymer Having a Cationic Filler Density Higher than 1 Meq/g and Having Primary Amine Functions.
This is a water-soluble polymer having at least 1 meq/g of primary amine function.
1. One method for preparing this polymer is the Hofmann degradation reaction on a base (co)polymer, well known to a person skilled in the art (FR 05.50135, JP 58-60094, JP 04-57992).
In practice, the base polymer used comprises:
at least one nonionic monomer selected from the group comprising acrylamide (and/or methacrylamide), N,N dimethylacrylamide and/or acrylonitrile, and optionally:
at least one unsaturated cationic ethylene monomer, preferably selected from the group comprising monomers of the dialkylaminoalkyl (meth)acrylamide, diallylamine, methyldiallylamine and their quaternary ammonium or acidic salts. Mention can be made in particular of dimethyldiallylammonium chloride (DADMAC), acrylamido propyltrimethyl ammonium chloride (APTAC) and/or methacrylamido propyltrimethyl ammonium chloride (MAPTAC), and/or at least one other nonionic monomer preferably selected from the group comprising N-vinyl acetamide, N-vinyl formamide, N-vinylpyrrolidone and/or vinyl acetate, and/or at least one anionic monomer of the acid or anhydride type selected for example from the group comprising (meth)acrylic acid, acrylamidomethylpropane sulphonic acid, itaconic acid, maleic anhydride, maleic acid, methallylsulphonic acid, vinylsulphonic acid and salts thereof.
It is important to note that, in combination with these monomers, it is also possible to use monomers insoluble in water such as acrylic, allyl or vinyl monomers comprising a hydrophobic group. During their use, these monomers are employed in very small quantities, lower than 20 moles percent, preferably lower than 10 moles percent, and they are preferably selected from the group comprising derivatives of acrylamide such as N-alkylacrylamide for example N-tert-butylacrylamide, octylacrylamide as well as N,N-dialkylacrylamides such as N,N-dihexylacrylamide, and derivatives of acrylic acid such as alkyl acrylates and methacrylates.
In a manner known per se, the base polymer may also be branched. As is well known, a branched polymer is a polymer having branches, groups or branchings from its main ring, roughly arranged in a plane.
The branching can preferably be carried out during (or optionally after) the polymerization, in the presence of a branching agent and optionally a transfer agent. A non-limiting list of branching agents is given below: methylene bisacrylamide (MBA), ethylene glycol di-acrylate, polyethylene glycol dimethacrylate, diacrylamide, cyanomethylacrylate, vinyloxyethylacrylate or methacrylate, triallylamine, formaldehyde, glyoxal, compounds of the glycidylether type such as ethyleneglycol diglycidylether, or epoxy or any other means well known to a person skilled in the art permitting cross-linkage.
In practice, the branching agent is methylene bis acrylamide (MBA) introduced at the rate of five to five thousand (5 to 5,000) parts per million by weight, preferably 5 to 2,000.
A non-limiting list of transfer agents is given below: isopropyl alcohol, sodium hypophosphite, mercaptoethanol, etc.
A person skilled in the art knows how to select the best combination according to his own knowledge and the present specification, and also from the examples that follow.
The (co)polymer serving as a basis for the Hofmann degradation reaction does not require the development of a particular polymerization method. The main polymerization techniques, well known to a person skilled in the art and usable are: precipitation polymerization, emulsion (aqueous or reverse) polymerization followed or not by a step of distillation and/or spray drying, and suspension polymerization or solution polymerization, these two techniques being preferred.
This base is characterized in that it has a molecular weight higher than 5,000 and without any upper limit.
The Hofmann degradation is then carried out by pouring on the base (preferably having a concentration higher than 10% by weight in aqueous solution) an alkaline solution of alkaline earth hypohalide and alkaline earth hydroxide, in steps or continuously, while absorbing the heat generated by the reaction and then pouring the whole into acid for decarboxylation to take place.
Once completed, the Hofmann degradation product is present in a concentration higher than 3.5% and generally higher than 4.5%.
Depending on the quantity of the alkaline solution of alkaline earth hypohalide and alkaline earth hydroxide introduced, variations in cationicity can be generated, associated with a quantity of amine functions produced on the carbon skeleton of the polymer.
Furthermore, it is possible to obtain a concentration of Hofmann degradation product in solution of about 10%, or even 15% or more, by using concentration methods such as ultrafiltration, diafiltration, and without any negative effect on the product.
2. Another method for preparing the “first” dry strength agent, also well known to a person skilled in the art, consists in an acidic or basic hydrolysis of a base (co)polymer of polyvinylformamide, and derivatives thereof.
In practice, the base polymer used comprises:
at least one nonionic monomer selected from the group comprising N-vinyl formamide, N-vinyl acetamide, N-vinylpyrrolidone and/or other groups such as vinyl acetate, and optionally:
at least one unsaturated cationic ethylene monomer, preferably selected from the group comprising monomers of the dialkylaminoalkyl (meth)acrylamide, diallylamine, methyldiallylamine and their quaternary ammonium or acidic salts. Mention can be made in particular of dimethyldiallylammonium chloride (DADMAC), acrylamido propyltrimethyl ammonium chloride (APTAC) and/or methacrylamido propyltrimethyl ammonium chloride (MAPTAC), and/or at least one nonionic monomer selected from the group comprising acrylamide (and/or methacrylamide), N,N dimethylacrylamide and/or acrylonitrile, and/or at least one anionic monomer of the acid or anhydride type selected for example from the group comprising (meth)acrylic acid, acrylamidomethylpropane sulphonic acid, itaconic acid, maleic anhydride, maleic acid, methallylsulphonic acid, vinylsulphonic acid and salts thereof.
It is important to note that, in combination with these monomers, it is also possible to use monomers insoluble in water such as acrylic, allyl or vinyl monomers comprising a hydrophobic group. During their use, these monomers are employed in very small quantities, lower than 20 moles percent, preferably lower than 10 moles percent, and they are preferably selected from the group comprising derivatives of acrylamide such as N-alkylacrylamide for example N-tert-butylacrylamide, octylacrylamide as well as N,N-dialkylacrylamides such as N,N-dihexylacrylamide, and the derivatives of acrylic acid such as alkyl acrylates and methacrylates.
In a manner known per se, the base polymer may also be branched. As is well known, a branched polymer is a polymer having branches, groups or branchings from its main ring, roughly arranged in a plane.
The branching can preferably be carried out during (or optionally after) the polymerization, in the presence of a branching agent and optionally a transfer agent. A non-limiting list of branching agents is given below: methylene bisacrylamide (MBA), ethylene glycol di-acrylate, polyethylene glycol dimethacrylate, diacrylamide, cyanomethylacrylate, vinyloxyethylacrylate or methacrylate, triallylamine, formaldehyde, glyoxal, compounds of the glycidylether type such as ethyleneglycol diglycidylether, or epoxy or any other means well known to a person skilled in the art permitting cross-linkage.
In practice, the branching agent is methylene bis acrylamide (MBA) introduced at the rate of five to five thousand (5 to 5,000) parts per million by weight, preferably 5 to 2,000.
A non-limiting list of transfer agents is given below: isopropyl alcohol, sodium hypophosphite, mercaptoethanol, etc.
The base (co)polymer does not require the development of a particular polymerization method. The main polymerization techniques, well known to a person skilled in the art and usable are: precipitation polymerization, emulsion (aqueous or reverse) polymerization followed or not by a step of distillation and/or spray drying, and suspension polymerization or solution polymerization, these two techniques being preferred.
This base is characterized in that it has a molecular weight higher than 5,000 and without any upper limit.
Depending on the quantity of acid or caustic introduced during the hydrolysis, it is possible to generate different cationicities, associated with the quantity of amine functions produced on the carbon skeleton of the polymer.
In practice, the “first” dry strength agent is introduced as the first, second or third component of the system, preferably before the third agent, at one or more injection points, into the suspension at the rate of 100 g/t to 20,000 g/t by weight of active matter (polymer) compared to the dry weight of the fibrous suspension, preferably 500 g/t to 5,000 g/t. Furthermore, the “first” dry strength agent may be introduced in a mixture with the “second agent” (the organic (co)polymer having a cationic filler density higher than 0.1 meq/g) at one or more injection points.
The injection or introduction of the (co)polymer having a cationic filler density higher than 1 meq/g and having primary amine functions according to the invention is possible in a thick slurry, or in a thin slurry, that is, in the thick slurry mixing chests after refiners up to the white water circuit.
B. The “Second” Dry Strength Agent: the Synthetic Organic (Co)Polymer Having a Cationic Filler Density Higher than 0.1 Meq/g.
In practice, the “second agent” is a water-soluble synthetic organic polymer that is purely cationic or amphoteric having a cationic filler density higher than 0.1 meq/g and a molecular weight of at least 5000, obtained from:
1 to 100 moles percent of at least one monomer having a cationic filler, and 0 to 99 moles percent of at least one monomer having a neutral and/or anionic filler.
The “second agent” may in particular be glyoxalated or not.
A non-limiting list of monomers which can be used are given below:
a) among the cationic monomers, those selected from the group comprising dimethylaminoethyl acrylate (ADAME) and/or dimethylaminoethyl methacrylate (MADAME) quaternized or salified, dimethyldiallylammonium chloride (DADMAC), acrylamido propyltrimethyl ammonium chloride (APTAC) and/or methacrylamido propyltrimethyl ammonium chloride (MAPTAC),
b) among the neutral monomers, the nonionic monomers selected from the group comprising acrylamide, methacrylamide, N,N dimethylacrylamide, N-vinyl pyrrolidone, N-vinyl acetamide, N-vinyl formamide, vinylacetate, esters acrylate, allyl alcohol,
c) among the anionic monomers: mention can be made, and in a non-limiting manner, of the anionic monomers having a carboxylic function selected from the group comprising: acrylic acid, methacrylic acid, maleic acid, itaconic acid and salts thereof, those having a sulphonic acid function are selected from the group comprising 2-acrylamido-2-methylpropane sulphonic acid (AMPS), vinyl sulphonic acid, methallyl sulphonic acid and salts thereof, those having a phosphonic acid function.
In combination with these monomers, it is also possible to use monomers insoluble in water such as acrylic, allyl or vinyl monomers comprising a hydrophobic group. During their use, these monomers are employed in very small quantities, lower than 20 moles percent, preferably lower than 10 moles percent, and they are preferably selected from the group comprising derivatives of acrylamide such as N-alkylacrylamide for example N-tert-butylacrylamide, octylacrylamide as well as N,N-dialkylacrylamides such as N,N-dihexylacrylamide, and the derivatives of acrylic acid such as alkyl acrylates and methacrylates.
The “second agent” does not require any development of a particular polymerization process. It can be obtained by all the polymerization techniques well known to a person skilled in the art: gel polymerization, precipitation polymerization, emulsion (aqueous or reverse) polymerization followed or not by a step of distillation and/or spray drying, and suspension polymerization or solution polymerization.
According to a particular and preferred embodiment, the “second agent” is a synthetic (co)polymer having a cationic filler density higher than 0.1 meq/g and is branched. It is obtained by the addition, before and/or after the polymerization, of a branching agent in the presence or not of a transfer agent. In practice, when the branching agent is methylene bis acrylamide (MBA), it is introduced at the rate of five to five thousand (5 to 5,000) parts per million by weight, preferably 5 to 2,000.
A non-limiting list of branching agents is given below: methylene bisacrylamide (MBA), ethylene glycol di-acrylate, polyethylene glycol dimethacrylate, diacrylamide, cyanomethylacrylate, vinyloxyethylacrylate or methacrylate, triallylamine, formaldehyde, glyoxal, compounds of the glycidylether type such as ethyleneglycol diglycidylether, or epoxy or any other means well known to a person skilled in the art permitting cross-linkage.
When the branching agent is glyoxal, it is added after the polymerization in a proportion of at least 0.5% of the (co)polymer to be glyoxalated.
In a particular embodiment, the (co)polymer having a cationic filler density higher than 0.1 meq/g is not glyoxalated.
A non-limiting list of transfer agents is given below: isopropyl alcohol, sodium hypophosphite, mercaptoethanol, etc.
In practice, the “second” dry strength agent is introduced at the first, second or third component of the system, at one or more injection points, into the suspension at the rate of 100 g/t to 20,000 g/t by weight of active matter (polymer) compared to the dry weight of the fibrous suspension, preferably 500 g/t to 5,000 g/t. Similarly, the “second agent” can be introduced in a mixture with the “first agent” at one or more injection points.
C. The “Third” Dry Strength Agent: the (Co)Polymer Having an Anionic Filler Density Higher than 0.1 Meq/g.
In practice, the “third agent” is a water-soluble synthetic organic polymer that is purely anionic or amphoteric having a cationic filler density higher than 0.1 meq/g and a molecular weight of at least 5000, obtained from:
1 to 100 moles percent of at least one monomer having an anionic filler, and 0 to 99 moles percent of at least one monomer having a neutral and/or cationic filler.
The “third agent” may particularly be glyoxalated or not.
A non-limiting list of monomers which can be used is given below:
a) among the anionic monomers, the anionic monomers having a carboxylic function selected from the group comprising acrylic acid, methacrylic acid, maleic acid, itaconic acid and salts thereof, those having a sulphonic acid function are selected from the group comprising 2-acrylamido-2-methylpropane sulphonic acid (AMPS), vinyl sulphonic acid, methallyl sulphonic acid and salts thereof, those having a phosphonic acid function,
b) among the monomers having a neutral filler, the nonionic monomers from the group comprising acrylamide, methacrylamide, N,N dimethylacrylamide, N-vinyl pyrrolidone, N-vinyl acetamide, N-vinyl formamide, vinylacetate, esters acrylate, allyl alcohol,
c) among the cationic monomers, the cationic monomers selected from the group comprising dimethylaminoethyl acrylate (ADAME) and/or dimethylaminoethyl methacrylate (MADAME) quaternized or salified, dimethyldiallylammonium chloride (DADMAC), acrylamido propyltrimethyl ammonium chloride (APTAC) and/or methacrylamido propyltrimethyl ammonium chloride (MAPTAC).
In combination with these monomers, it is also possible to use monomers insoluble in water such as acrylic, allyl or vinyl monomers comprising a hydrophobic group. During their use, these monomers are employed in very small quantities, lower than 20 moles percent, preferably lower than 10 moles percent, and they are preferably selected from the group comprising derivatives of acrylamide such as N-alkylacrylamide for example N-tert-butylacrylamide, octylacrylamide as well as N,N-dialkylacrylamides such as N,N-dihexylacrylamide, and the derivatives of acrylic acid such as alkyl acrylates and methacrylates.
The “third agent” does not require any development of a particular polymerization process. It can be obtained by all the polymerization techniques well known to a person skilled in the art: gel polymerization, precipitation polymerization, emulsion (aqueous or reverse) polymerization followed or not by a step of distillation and/or spray drying, and suspension polymerization or solution polymerisation.
According to a particular and preferred embodiment, the “third” dry strength agent is a (co)polymer having an anionic filler density higher than 0.1 meq/g and is branched. It is obtained by the addition, before, during and/or after the polymerization, of a branching agent in the presence or not of a transfer agent. In practice, when the branching agent is methylene bis acrylamide (MBA), it is introduced at the rate of five to five thousand (5 to 5,000) parts per million by weight, preferably 5 to 2,000.
When the branching agent is glyoxal, it is added after the polymerization in a proportion of at least 0.5% of the (co)polymer to be glyoxalated.
A non-limiting list of branching agents is given below: methylene bisacrylamide (MBA), ethylene glycol di-acrylate, polyethylene glycol dimethacrylate, diacrylamide, cyanomethylacrylate, vinyloxyethylacrylate or methacrylate, triallylamine, formaldehyde, glyoxal, compounds of the glycidylether type such as ethyleneglycol diglycidylether, or epoxy or any other means well known to a person skilled in the art permitting cross-linkage.
A non-limiting list of transfer agents is given below: isopropyl alcohol, sodium hypophosphite, mercaptoethanol, etc.
In practice, the “third” dry strength agent is introduced at the first, second or third component of the system, preferably after the first dry strength agent, at one or more injection points, into the suspension at the rate of 100 g/t to 20,000 g/t by weight of active matter (polymer) compared to the dry weight of the fibrous suspension, preferably 500 g/t to 5,000 g/t.
For reasons of marketing, an attempt is made to propose dry strength agents of the invention in their most concentrated possible form, using suitable concentration techniques well known to a person skilled in the art.
A final object of the invention is a sheet of paper or cardboard obtainable by the method previously described. This sheet is distinguished from the sheets of the prior art by its exceptional dry strength characteristics.
The following examples illustrate the invention without limiting its scope.
EXAMPLES
Presentation of Dry Strength Agents
a. The “First” Dry Strength Agent: Polyvinylamine
The polymers P1 and P2 were prepared.
P1: The polymer was obtained by a Hofmann degradation reaction on a homopolymer of acrylamide polymerized in aqueous solution containing 25% concentration and having a viscosity of 8,500 cps (molecular weight about 200,000). The Hofmann degradation was carried out at the temperature of 10° C. with sodium hypochlorite, sodium hydroxide and hydrochloric acid.
The product had a final concentration of 7% and a cationic filler of 6.2 meq/g.
P2: The polymer was obtained by basic hydrolysis of a homopolymer of vinylformamide polymerized in aqueous solution containing 25% concentration and having a viscosity of 36,000 cps (molecular weight about 300,000).
The hydrolysis was carried out with caustic at 80° C. for 5 h.
The product had a final concentration of 14.5% and a cationic filler of 6.2 meq/g.
b. The “Second” Dry Strength Agent: Cationic Resin
2 types of polymer are exemplified:
C1: This is an acrylamide/chloromethylated ADAME copolymer (65/35 moles percent) branched with MBA, polymerized in aqueous solution containing 15% concentration and having a viscosity of 3,000 cps.
C2: This is a glyoxalated acrylamide/DADMAC copolymer (95/5 moles percent). The base (before glyoxalation) was polymerized in aqueous solution containing 40% concentration and having a viscosity of 3,000 cps. The product after glyoxalation (30 wt % of glyoxal) had a viscosity of 20 cps and a concentration of 7.5%.
c. The “Third” Dry Strength Agent: Anionic Resin
The anionic resins tested were copolymers of acrylamide and acrylic acid salts obtained by solution polymerization at 15%. Some polymers have a linear structure and others branched. Furthermore, we also prepared an amphoteric linear polymer with an overall anionic filler (A3).
In the following examples, the following polymers are used:
Anionicity
Viscosity of polymer
Anionic resin
Composition
Molar ratio
(meq/g)
Structure
solution (cps)
A1
AM/AA
70/30
3.85
Linear
2,500
A2
AM/AA
70/30
3.85
Branched
2,500
(MBA)
A3
AM/AA/
83/10/7
0.48
Linear
9,000
ADAME MeCl
A4
AM/AA
55/28/17
3.75
Branched
2,500
(glyoxal)
(glyoxal)
AA = Sodium acrylate
AM = Acrylamide
ADAME MeCl = Chloromethylated dimethylaminoethyl acrylate
Procedure for Testing Dry Strength Properties
The paper handsheets are prepared with an automatic dynamic handsheet machine. The pulp is first prepared by disintegrating 90 grams of virgin kraft fibres in 2 litres of hot water for 30 minutes. The slurry obtained is then diluted to a total volume of 9 litres. Once the consistency is measured accurately, the necessary quantity of this slurry is withdrawn in order to finally obtain a sheet with a weight of 60 g/m 2 .
The slurry is then introduced into the chest of the dynamic handsheet machine, diluted to a consistency of 0.32% and moderately stirred with a mechanical stirrer to homogenize the fibrous suspension.
In manual mode, the slurry is pumped to the nozzle to prime the circuit.
A blotter and the papermaking wire cloth are placed in the bowl of the dynamic handsheet machine before rotating the bowl at 900 rpm and constructing the waterwall. The different dry strength agents are then introduced into the stirred fibrous suspension with a contact time of 30 seconds for each polymer. The sheet is then prepared (in automatic mode) by 22 return trips of the nozzle projecting the slurry into the waterwall. Once the water is drained and the automatic sequence is terminated, the wire cloth with the fibre network is removed from the bowl of the dynamic handsheet machine and placed on a table. A dry blotter is placed on the side of the wet fibre pad and pressed once with a roller. The whole is turned over and the wire cloth is delicately separated from the fibre pad. A second dry blotter is placed on the sheet (between the two blotters) and pressed once under a press delivering 4 bar and then dried in a stretched drier for 9 min at 107° C. The two blotters are then removed and the sheet is stored overnight in a room with controlled humidity and temperature (50% relative humidity and 23° C.). The dry and wet strength properties of all the sheets obtained by this procedure are then determined.
Burst strength is measured with a Messmer Buchel M 405 burst tester (mean of the 14 measurements).
The wet tensile strength and/or tensile energy absorbed (TEA) are measured in the machine direction with a Testometric AX tensile tester (mean of 5 samples).
The wet tensile strength is measured in the machine direction with a Testometric AX tensile tester after the sample has been soaked for 20 seconds in a Finch cell filled with deionized water (mean of 5 samples).
In all the following examples, unless otherwise indicated, the paper sheets are prepared by the above procedure, introducing them by following the order of introduction presented in the tables.
The tests are performed with a neutral pH slurry. The tests annotated (inv) correspond to those of the invention.
TABLE 1
Effect associated with the “first” dry strength agent: polyvinylamine
Dry
Wet
tensile
Dry
tensile
Sheet
1 st
2 nd
3 rd
Burst
strength
TEA
strength
No.
product
product
product
index
(km)
(j/m 2 )
(m)
Control
—
—
—
1.436
3.760
40.24
40
1
C1
A2
—
1.975
4.437
53.51
146
2 (inv)
C1
P1
A2
2.130
4.646
60.01
215
3 (inv)
C1/P1
A2
2.003
4.530
61.86
225
(in mixture)
4
C2
A2
—
1.875
3.973
49.61
286
5 (inv)
C2
P1
A2
2.330
4.620
66.63
591
6 (inv)
C2
P2
A2
2.361
4.591
68.16
493
Proportions in sheets 1 and 4: 1 st product = 0.55%; 2 nd product = 0.30%
Proportions in sheets 2, 3, 5, 6: 1 st product = 0.30%; 2 nd product = 0.25%; 3 rd product = 0.30%
The table above demonstrates the unexpected effect resulting from the use of a polyvinylamine (“first” dry strength agent) in combination with a conventional two-component type of system. It is also found that a polyvinylamine issuing from a Hofmann degradation or a polyvinylformamide hydrolysis serve to obtain an identical dry strength level.
Remark: It should be observed that polymer C2 has a substantial negative effect on the wet strength, causing process difficulties such as during the reduction of the sheet to pulp for recycling dry fragments.
TABLE 2
Synergy provided by the three-component system
Wet
tensile
Dry
Sheet
1 st
2 nd
3 rd
strength
TEA
No.
product
product
product
Burst index
(m)
(j/m 2 )
Control
—
—
—
1.436
3.760
40.24
7
C2
—
—
1.800
3.901
42.05
8
P1
—
—
1.470
3.822
41.36
9
C2
P1
—
1.996
3.950
53.03
4
C2
A2
—
1.875
3.973
49.61
1
C1
A2
—
1.975
4.437
53.51
5 (inv)
C2
P1
A2
2.330
4.620
66.63
2 (inv)
C1
P1
A2
2.130
4.646
60.01
Proportions in sheets 7 and 8: 1 st product = 0.55%;
Proportions in sheets 9, 4 and 11: 1 st product = 0.55%; 2 nd product = 0.30%;
Proportions in sheets 5 and 2: 1 st product = 0.30%; 2 nd product = 0.25%; 3 rd product = 0.30%
These results clearly show that only the synergy of the three dry strength agents of the invention serves to obtain the unequalled performance levels that cannot be obtained by conventional systems with one or two components.
TABLE 3
Effect of proportioning
Wet
tensile
Dry
Sheet
1 st
2 nd
3 rd
strength
TEA
No.
product
product
product
Burst index
(m)
(j/m 2 )
Control
1.436
3.760
40.24
2 (inv)
0.3
0.25
0.3
2.130
4.646
60.01
10 (inv)
0.3
0.17
0.2
2.025
4.486
58.74
11 (inv)
0.3
0.1
0.15
1.997
4.466
56.84
5 (inv)
0.3
0.25
0.3
2.330
4.620
66.63
12 (inv)
0.3
0.17
0.2
2.316
4.585
63.45
13 (inv)
0.3
0.1
0.15
2.327
4.528
62.35
14
0.25
0.3
—
1.908
4.403
55.43
Sheets 2, 10 and 11: 1 st product = C1; 2 nd product = P1; 3 rd product = A2
Sheets 5, 12 and 13: 1 st product = C2; 2 nd product = P1; 3 rd product = A2
Sheets 14: 1 st product = P1; 2 nd product = A2 (two-component system)
The table above shows that the synergy between the three products is affected even in low proportions.
Sheets 5 and 13 show that the lowering of the total proportion from 0.85% to 0.55% does not substantially decrease performance.
Similarly, sheets 13 and 14 show that with an identical total proportion the combination of the three agents of the invention serves to obtain much higher dry strength levels than the combination of polyvinylamine+anionic polymer, which is nevertheless already very efficient (cf. FR 05.50135).
TABLE 4
Effect of type of anionic polymer used as anionic resin
Wet
tensile
Dry
Sheet
1 st
2 nd
3 rd
strength
TEA
No.
product
product
product
Burst index
(m)
(j/m 2 )
Control
—
—
—
1.436
3.760
40.24
15 (inv)
C2
P1
A1
2.247
4.592
65.87
5 (inv)
C2
P1
A2
2.330
4.620
66.63
16 (inv)
C2
P1
A3
2.203
4.498
63.12
17 (inv)
C2
P1
A4
2.191
4.486
63.09
It appears clearly that the dry strength is increased by using a branched polymer (A2) rather than a linear polymer (A1) as the anionic resin. It should also be noted that an amphoteric polymer (A3) or a glyoxalated anionic polymer (A4) serve to obtain the same very satisfactory level of performance.
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A method for making a sheet of paper and/or cardboard and the like, comprises, prior to forming said sheet, adding to the fibrous suspension, separately or mixed, in any sequence of introduction, into one or more injection points, at least three dry strength agents respectively: first agent corresponding to a (co)polymer having a cationic filler density higher than 1 meq/g and exhibiting primary amine functions; a second agent corresponding to a synthetic organic (co)polymer having cationic filler density higher than 0.1 meq/g; and a third agent corresponding to a (co)polymer having an anionic filler density higher than 0.1 meq/g.
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[0001] This application claims Paris Convention priority of DE 100 OG 323.3 filed Feb. 12, 2000 the complete disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The invention concerns an NMR (=nuclear magnetic resonance) probe head comprising an RF (=radio frequency) receiver coil system, which can be cooled down to cryogenic temperatures, and a room temperature pipe extending in a z direction for receiving a sample tube containing a sample substance to be examined through NMR measurements.
[0003] A cooled NMR probe head of this type is e.g. known from U.S. Pat. No. 5,247,256.
[0004] The probe head is installed in a magnet, for generating a highly homogeneous static B 0 field, and comprises RF receiver coils disposed about a z axis which are cooled down during operation to temperatures of approximately 10 to 25 K by means of suitable heat exchangers and heat conducting elements to improve the signal-to-noise-ratio of the received NMR signal during the measurement. The RF receiver coils are in an evacuated region for heat insulation reasons which is formed essentially by a usually metallic casing of the probe head which is penetrated by a room temperature pipe disposed cylindrically about the z axis for receiving a sample tube. To permit passage of the RF signals from the sample to the RF receiver coils, the otherwise metallic room temperature pipe is replaced in the axial region of the coils by an RF permeable inner pipe, in most cases a glass pipe, which is connected to the metallic parts of the room temperature pipe in a vacuum-tight fashion.
[0005] After insertion of the sample tube into the room temperature pipe from the bottom, it is substantially maintained at a desired temperature (usually approximately 300 K) using warm air flowing from below through the room temperature pipe to control the temperature of the sample substance. This, however, causes the associated problem that the measuring sample “feels” the considerably cooler surroundings of the NMR resonator, cooled down to 10 to 25 K, and radially radiates heat in this direction. This lost heat must be continuously replenished by the surging warm tempering air flow to ensure that the measuring sample remains essentially at the desired temperature. In consequence, an axial and radial temperature gradient is produced in the measuring sample which strongly impairs the NMR measurement.
[0006] It is therefore the underlying purpose of the present invention to provide a cooled NMR probe head comprising the above-mentioned features wherein the temperature gradient in the z direction occurring during operation is considerably reduced without thereby impairing the NMR measurement.
SUMMARY OF THE INVENTION
[0007] This object is achieved in accordance with the present invention in a both surprisingly simple and effective manner by providing a tempering means between the RF receiver coil system and the sample tube which extends in the z direction and radially surrounds the sample tube and is almost completely transparent to RF fields, or at least has an absorption for RF fields of <5%, preferably <1%.
[0008] In addition to exchangeable sample tubes, the NMR probe heads in accordance with the invention also include so-called flow-through heads wherein the sample tube remains fixedly installed and the fluid to be examined is introduced through a thin conduit on the one side (bottom) and is guided out on the other side (top). Probe heads of this type may be used in continuous passage and also in a flow and stop mode (for an extended measuring period). These probe heads are used for rapid introduction of the sample as well as for an important analysis step following a liquid chromatography separating cell. The former are called flow-through probe heads, the latter LC-NMR coupling. Probe heads of this type are also referred to as LC heads (liquid chromatography, in particular also HPLC High Pressure Liquid Chromatography). Probe heads of this type can particularly profit from cryotechnology and also from the modifications in accordance with the invention.
[0009] These inventive modifications prevent dissipation of heat from the measuring sample and thus uneven cooling without significantly impairing the received NMR signals. The principal advantage of such a tempering means compared to a conventional heated air flow for the sample tube is the fact that the thermal efficiency can act uniformly through the entire axial length of the sample tube. The central area is thus as well tempered as the edge areas thereby effectively preventing axial temperature gradients.
[0010] The heating means in accordance with the invention can be used individually and also in combination with an air flow tempering means. A combination of both heating types is particularly advantageous for optimum suppression of the residual temperature gradients.
[0011] In contrast thereto, a conventionally heated air flow, without the heating means in accordance with the invention, usually enters into the room temperature pipe at the lower end of the sample tube, starts to heat up the sample tube at this location and continues to cool down while rising in the axial direction. The temperature of the heated air flow in the upper region of the sample tube will therefore always be less than in the lower area thereby inevitably reducing the tempering performance in the upper region of the sample tube. As a result, there will always be an axial temperature gradient which can be somewhat reduced by increasing the amount of air per unit time, however cannot be prevented in principle. Moreover, the corresponding countermeasures are highly limited since, if the amount of air per unit time is too large, vibration free positioning or proper rotation of the sample tube can no longer be guaranteed.
[0012] Through corresponding selection of the tempering means with respect to its absorption behavior of RF fields, one tries to obtain an almost complete transparency to the RF fields to allow as free a passage as possible of the measuring signal from the sample to the RF receiver coil system.
[0013] The tempering means of the inventive NMR probe head can be realized in technically completely different ways, e.g. through heating with electric current but also heating through radiation or thermal conduction in the region about the sample tube.
[0014] A particularly preferred embodiment of the inventive NMR probe head is characterized in that the tempering means comprises a layer radially surrounding the sample tube in the axial region of the RF receiver coil system having a radial thickness of <1 mm, preferably <50 μm and which is made from a material which at least partially absorbs radiation in a wavelength range of 100 nm≦λ≦100 μm and which is transparent to radiation in a wavelength range of λ>100 mm. Absorption of thermal radiation in the layer permits temperature control of the sample tube in the corresponding axial region.
[0015] The NMR probe head in accordance with the invention preferably comprises a heating means for uniformly heating the layer, which can be designed with different technical means.
[0016] A preferred further development is characterized in that the heating means comprises a device for irradiating the layer with radiation in a wavelength range of 100 nm≦λ≦100 μm, in particular with thermal radiation thereby providing contact-free and uniform heating of the layer.
[0017] The device for irradiating the layer is preferably disposed on the side of the room temperature bore facing the RF receiver coil system. Since the receiver coil system is generally accommodated in an evacuated region, the thermal radiation can pass through the vacuum to the heating layer without obstruction.
[0018] One further development is particularly space-saving with which the layer is disposed on the side of the room temperature pipe facing the RF receiver coil system.
[0019] Many materials which can be used to construct the room temperature pipe already absorb in the desired wavelength range such that heating up using radiation does not require a special radiation-absorbing layer.
[0020] The radiation absorbing heating layer may surround the room temperature pipe over a large area. Alternatively, the layer may be disposed about the room temperature pipe in axially extending strips disposed at a separation from one another in the peripheral direction.
[0021] One further development is particularly preferred in which the layer is electrically conducting and can be heated through application of an electric voltage.
[0022] Alternatively or additionally, a further embodiment provides that the tempering means comprises one or more heating coils of thin, in particular layered, electrically good conducting material each comprising an outgoing and return conductor. The outgoing and return conductors of the heating coils are electrically connected to one another at one end and can be supplied with heating current from a current source at the other end.
[0023] A preferred further development of this embodiment is characterized in that the heating coils are formed of an electrically conductive layer which radially surrounds the sample tube in the axial region of the RF receiver coil system, has a radial thickness of <1 mm, preferably <50 μm and is transparent to radiation in a wavelength range of λ>100 mm. This layer may be radiation-absorbing as in the above-described embodiments to allow heating in two different ways.
[0024] In a particularly preferred manner, the outgoing and return conductors of the heating coils are disposed bifilarly at as small a separation from one another as possible to minimize generation of a disturbing magnetic field during current flow.
[0025] In this connection, it is advantageous if the outgoing and return conductors of the heating coils consist of two longitudinal strips disposed one on top of the other which are electrically insulated from one another by an insulation layer or insulation strip.
[0026] A further development is particularly preferred with which the outgoing and return conductors of the heating coils are made from materials having different magnetic susceptibilities and which are selected such that each overall heating coil is magnetically compensated towards the outside to prevent formation of additional magnetic fields during current flow which would deteriorate the resolution of the recorded NMR spectra.
[0027] The tempering means can be geometrically designed such that one or more heating coils are disposed in a spiral fashion about the room temperature pipe.
[0028] As an alternative, it is also possible to dispose several, preferably at least 8, heating coils at a separation from one another in the peripheral direction about the z axis of the room temperature pipe, which extend parallel to the z direction.
[0029] Advantageously, the heating coils are spatially oriented such that they are minimally coupled to the RF receiver coil system.
[0030] One embodiment of the heating coils having a material exhibiting as good an electrical conductance as possible (e.g. Cu) is particularly preferred wherein the conductors have rectangular, possibly square or circular cross-sections (typically of a magnitude of 10 μm×10 μm or less). Due to the resulting very small overall surface covering, the room temperature pipe maintains its good permeability to RF fields, and the RF losses are also very low due to both the small surfaces of the heating conductors and the good electrical (and thus RF) conductivity.
[0031] In a preferred further development of the above-described embodiment, a low-pass filter may be provided between the current source and the heating coils to minimize signal distortion and residual attenuation.
[0032] One further development is also preferred in which a parallel resonant circuit is provided between the current source and the heating coils whose resonance frequency is the most sensitive RF frequency relevant for NMR measurements. Such a rejector circuit also prevents transmission of disturbing signals to the RF receiver coil system and minimizes unwanted coupling-out of the RF signals via the heating coils.
[0033] In a further development, the current source advantageously supplies the heating coils with alternating current in order to keep further disturbances in the static magnetic field as small as possible.
[0034] In this connection, the angular frequency OH for the heating current I H =I 0 ·cos ω H t through the heating coils should be selected such that the corresponding side bands are outside of the observeable NMR spectrum.
[0035] In particular, the following should hold: 1 kHz≦ω H /2π≦10 GHz, preferably 10 kHz≦ω H /2π≦1 MHz. It is generally advantageous if the tempering means, in particular the room temperature pipe itself, a heating layer and/or heating coils are formed of a material having good thermal conductance which permits particularly uniform heating along the entire surface of the corresponding heating means to counteract formation of temperature gradients in the sample tube.
[0036] A particularly preferred embodiment of the NMR probe head in accordance with the invention provides for radiation shields disposed between the RF receiver coil system and the room temperature pipe which surround the room temperature pipe in a radial direction, extend in the z direction and are made of one or more materials oriented in the z direction which are almost completely transparent to RF fields or at least have an absorption of <5%, preferably <1% for RF fields.
[0037] Although cryotechnology has used radiation shields for some time to curtail heat radiation losses, this procedure is not directly applicable for a cooled NMR probe head since the normally metallic radiation shields, which reflect heat radiation, either completely block or at least strongly impair propagation of RF fields from the measuring sample to the RF receiver coils such that the incoming NMR signals are at least highly attenuated, distorted or completely unusable.
[0038] In accordance with the inventive solution, the radiation shields provided in the vacuum between the RF coils and the room temperature pipe solely comprise materials which are oriented in the z direction. The axial orientation of the radiation shield material prevents their finite susceptibility from impairing the resolution of the NMR signals. On the other hand, the physical properties of the materials should be such as to effect as large a transparency as possible in the region of radio frequency radiation. In most cases, this material property has the associated disadvantage that reflection of lost heat back towards the measuring sample is not very high.
[0039] It is advantageous if the radiation shields have at least a minimum separation from one another in the radial direction and do not contact each other or at the most contact at points or linearly to prevent direct heat conduction between the individual radiation shields in a radial direction which would lead to a thermal “short circuiting”. Occasional contact between the radiation shields is not a serious problem, in particular if the chosen material has very low heat conduction. As long as the individual contacting points or lines are sufficiently spaced apart from one another, the overall heat conduction between the radially disposed radiation shields can be essentially neglected for the purposes of the invention.
[0040] One further development is particularly preferred, wherein the radiation shields are constructed from a material which reflects or at least absorbs radiation in a wavelength range of 10 μm≦λ≦100 μm and which is transparent to radiation in a wavelength range of λ>100 mm. The former wavelength range corresponds to heat radiation at a temperature of between approximately 20 K to 300 K which corresponds to the temperature difference between the measuring sample and the cooled NMR coils. The latter wavelength range corresponds to radiation of a frequency below 3 GHz, wherein the RF range which is important for NMR measurements is between several MHz and below approximately 1 GHz.
[0041] An optimum material which has practically no absorption losses in the considered RF range, and on the other hand is not transparent in the above-mentioned heat radiation range, is e.g. glass or quartz.
[0042] The radiation shields of the NMR probe head in accordance with the invention could theoretically be configured as tubes coaxially surrounding the room temperature pipe. The tube material would, however, normally be excessively thick. The radiation shields could also be constructed from a unidirectional foil whose production and processing is, however, relatively difficult. Orientation of the foil along the z axis can be realized e.g. through application of mechanical tensile stress. In contrast thereto, one embodiment is preferred, in which the radiation shields are made from a unidirectional fabric. Unidirectional fabric of this type having correspondingly suitable materials is commercially available.
[0043] These fabrics preferably consist of fiber mats, in particular fiber glass mats which are made of fibers having a diameter of less than 10 μm and a total thickness of approximately 30 μm. When using such fiber glass mats, it would be feasible to wind them in several layers in a spiralling fashion about the room temperature pipe on its vacuum side instead of providing a radial sequence of individual cylindrical radiation shields.
[0044] In a further particularly preferred embodiment, the radiation shields are formed of rods or fibers, preferably glass fibers and/or quartz fibers oriented in the z direction and radially disposed about the axis of the room temperature pipe. Fibers of this type are available with diameters of between 10 and 50 μm. Although, glass filaments having a diameter of less than 5 μm are also available, these would probably be difficult to work with.
[0045] In a preferred further development, the radiation shields are formed of fiber bundles having somewhat higher overall mechanical stability than the individual filaments and are thus easier to work, similar to rods.
[0046] In embodiments of the invention, the rods or fibers may be disposed freely in space and be fastened only at their ends. Alternatively, the rods or fibers may be mounted to a support pipe disposed coaxially with respect to the room temperature pipe, preferably on the side of the room temperature pipe facing the RF receiver coil system.
[0047] In a preferred further development the rods or fibers are mounted to the support pipe or room temperature pipe using a glue transparent to RF radiation in order to prevent attenuation of the RF radiation from the measuring sample to the RF receiver coil due to gluing.
[0048] One further development is also advantageous, wherein the rods or fibers are densely packed in the peripheral direction about the axis of the room temperature pipe to prevent visible gaps “as viewed” in the radial direction. In this fashion, the rods or fibers each form a radiation shield connected in the peripheral direction.
[0049] One embodiment of the NMR probe head in accordance with the invention is particularly preferred in which a centering device is disposed about the axis of the room temperature pipe for centering the sample tube in its measuring position. The transverse temperature gradients, extending radially with respect to the z axis, which can occur during operation of a cooled NMR probe head are given by the product of the heat loss per unit surface, the reciprocal value of the mass flow of tempering gas and a symmetry factor which includes a displacement or angular deviation of the sample tube axis from the z axis of the room temperature pipe. Since this asymmetry appears as a factor in the overall product, even small inclinations of the measuring sample within the room temperature pipe have a large influence on the tempering flow. Therefore, the proposed centering device can have an additional considerable effect with regard to a reduction in the temperature gradients and an improvement of the quality of the NMR signals.
[0050] In a further development which is particularly easy to realize, the centering device comprises one or more spacers disposed between the room temperature pipe and the sample tube and symmetrically distributed about the z axis of the room temperature pipe.
[0051] These spacers may be disposed in the area of the bottom of the sample tube in its measuring position and/or in the area of the feed opening of the room temperature pipe on the side of the room temperature pipe facing the sample tube. Alternatively, the spacers may extend over the entire axial length of the RF receiver coil system.
[0052] One further development is also advantageous, wherein the spacers consist of strips of elastic material extending in the direction of the z axis which are rigidly connected to the room temperature pipe at their ends facing away from the sample glass in its measuring position and whose ends facing the sample glass in its measuring position have a bead which is bulged towards the sample glass and whose free leg seats on the room temperature pipe.
[0053] To prevent disturbance of the NMR measurements, the spacers should be produced from a material which is transparent to RF radiation.
[0054] In a preferred further development, the spacers consist of sheet metal strips having a thickness of approximately 100 μm and a width transverse to the z axis of approximately 0.5 mm to 2 mm, preferably approximately 1 mm.
[0055] Further advantages of the invention can be extracted from the description and the drawing. The features mentioned above and below can be used in accordance with the invention either individually or collectively in any arbitrary combination. The embodiments shown and described are not to be understood as exhaustive enumeration but rather have exemplary character for describing the invention.
[0056] The invention is shown in the drawing and explained in more detail by means of embodiments.
BRIEF DESCRIPTION OF THE DRAWING
[0057] [0057]FIG. 1 a shows a schematic vertical section along the z axis through an NMR probe head in accordance with the invention in the vicinity of an RF receiver coil system, including tempering means and associated temperature dependence along the z axis;
[0058] [0058]FIG. 2 shows a schematic vertical section through a cooled prior art NMR probe head with associated temperature dependence in the direction of the z axis;
[0059] [0059]FIG. 3 a shows a schematic horizontal section through an arrangement comprising a sample tube introduced asymmetrically into the room temperature pipe;
[0060] [0060]FIG. 3 b shows the temperature distribution in the z direction associated with the arrangement according to FIG. 3 a;
[0061] [0061]FIG. 4 a shows a schematic vertical section through a room temperature pipe with asymmetrically introduced sample tube and indicated convection flows within the measuring sample;
[0062] [0062]FIG. 4 b shows the associated temperature dependences in the direction of the z axis on the left and right-hand side of the arrangement of FIG. 4 a;
[0063] [0063]FIG. 5 shows a schematic temperature dependence of the tempering gas in the direction of the z axis with the sample tube being introduced asymmetrically into the room temperature pipe, with the inner side of the room temperature pipe in the region of the RF receiver coils having good heat-conducting properties;
[0064] [0064]FIG. 6 a shows a schematic representation of an embodiment of the invention with two opposite electric heating coils extending along the room temperature pipe;
[0065] [0065]FIG. 6 b corresponds to FIG. 6 a , wherein the surface A surrounded by the heating coils is larger;
[0066] [0066]FIG. 6 c shows an embodiment with spiralling heating coil;
[0067] [0067]FIG. 7 shows a schematic representation of an embodiment with two thin layers of a heating coil which are separated through an insulation foil;
[0068] [0068]FIG. 8 a shows a circuit diagram for a heating coil with upstream low-pass filters;
[0069] [0069]FIG. 8 b corresponds to FIG. 8 a , however, with upstream rejector circuits;
[0070] [0070]FIG. 9 shows a schematic vertical section through an inventive arrangement comprising heating means, temperature sensors and electronic temperature control;
[0071] [0071]FIG. 10 a shows a schematic vertical section through an inventive NMR probe head with thermal shields between the room temperature pipe and the RF receiver coil system;
[0072] [0072]FIG. 10 b shows a schematic horizontal section through an arrangement according to FIG. 10 a in the axial region of the RF receiver coil system;
[0073] [0073]FIG. 11 a shows a schematic vertical section through an inventive arrangement with centering device; and
[0074] [0074]FIG. 11 b shows a horizontal section through an arrangement according to FIG. 11 a.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0075] [0075]FIG. 1 shows a schematic vertical section through an inventive NMR probe head comprising a tempering means 11 in the axial region of the inner tube 5 of a room temperature pipe 4 and the associated temperature dependence along the z axis. The tempering means 11 can be effected e.g. via electric heating and/or radiation heating of a corresponding surface on the room temperature pipe 4 in the region of the inner tube 5 by means of a heating means 19 . The temperature dependence along the z axis shown on the right-hand side illustrates (solid lines) the situation without tempering means and (broken lines) the situation with regulated tempering means, indicating a nearly constant temperature along the entire z axis.
[0076] Further details of the inventive NMR sample head can be extracted i.a. from FIG. 10 a described below.
[0077] The operation of the inventive arrangement is explained below:
[0078] [0078]FIG. 2 schematically shows a section of an NMR probe head of prior art, wherein radiative heat flow Q passes from a sample tube 6 in a radial direction towards the RF receiver coil system 1 since the receiver coil system 1 is maintained at a cryogenic temperature of approximately 25 K while the sample tube 6 should be held approximately at room temperature using the tempered air flow 8 supplied from below. The heat radiation from the sample tube 6 results, taking into consideration the heat supplied by the tempering flow 8 , in a temperature dependence in an axial direction within the sample tube 6 as schematically shown on the right hand side of FIG. 2.
[0079] The relatively high temperature gradients within the sample substance 7 often result in an undesired deterioration of the recorded NMR spectra. The lines widen due to the temperature dependence of the chemical shift which can prevent simultaneous shimming of two substances. This effect is particularly distinct with water.
[0080] In addition, convection effects may occur if the temperature gradient has exceeded a critical value. The resulting fluctuations can considerably impair stability during shimming and during NMR experiments.
[0081] In addition to the temperature gradients in the z direction, transverse gradients can also occur if the sample tube 6 is not positioned exactly in the center of the room temperature pipe 4 , as schematically shown in the horizontal section of FIG. 3 a.
[0082] Due to the differing mass flow resulting from the differing flow resistances on the left (L) and right (R) sides, differing longitudinal gradients occur on either side, leading to a transverse temperature gradient which becomes more distinct towards the top, as shown in FIG. 3 b . Of the three temperature dependences shown, the middle one illustrates the symmetric case. This gradient additionally promotes formation of convection within the normally liquid sample substance 7 , as is schematically shown in FIG. 4 a . The associated temperature dependences in the z direction are shown in FIG. 4 b . The temperature dependence on the right-hand side (=R) may thereby considerably differ from the temperature dependence on the left-hand side (=L).
[0083] To counteract this effect, the central part 5 of the room temperature pipe 4 is made from a material having good heat conduction to thereby considerably reduce the transverse temperature gradients (x-y direction). However, only those materials are acceptable having negligibly small RF radiation absorption while also exhibiting the required high heat conductivity. A concrete example is sapphire.
[0084] [0084]FIG. 5 shows this situation with poor heat conductivity (broken lines) and with good heat conductivity (solid lines) for the room temperature pipe 4 , in particular of the inner pipe 5 . The temperature dependence along the z axis cannot be substantially influenced thereby (except for averaging of the two extrema). Only the temperature dependence directly before the upper clamping point of the sample tube 6 can be improved. It is not possible to eliminate a linear temperature gradient merely through heat-conducting measures on the room temperature pipe 4 .
[0085] This is where the invention starts, according to which a tempering means 11 is disposed between the RF receiver coil system 1 and the sample tube 6 which extends in the z direction and surrounds the sample tube in the radial direction and is almost completely transparent to RF fields.
[0086] In embodiments of the invention which are not further represented in the drawing, the tempering means 11 consists of a heating means 19 . A layer can be additionally disposed on the sample tube 6 for absorbing thermal radiation which achieves the considerably improved axial temperature dependence in the sample tube 6 described above for FIG. 1. The tempering means 11 can comprise supplementary, additionally or alternatively also electrically heatable elements, in particular heating coils 12 , 12 ′ as shown in FIG. 6 a opposite to and in the z direction along the inner tube 5 of the room temperature pipe 4 .
[0087] In any case it is recommended to produce the inner tube 5 of a material having good heat conductance (e.g. sapphire).
[0088] [0088]FIG. 6 b schematically shows a heating coil 12 ″ comprising a relatively large surface A which should be prevented in practice. The surface A of the coil should be minimized since too large a surface could cause considerable disturbance of the homogeneous magnetic field B 0 in the measuring position of the inventive NMR sample head due to fields which extend perpendicular thereto when current flows through the heating coils.
[0089] [0089]FIG. 6 c shows an inventive arrangement comprising a heating coil 12 ′″ spirally wound about the inner tube 5 wherein the surface between the two electric conductors is kept as small as possible for the above-mentioned reasons.
[0090] In a further embodiment it can be advantageous to form the heating coil 13 of two thin layers 13 ′, 13 ″—as shown in FIG. 7—which are disposed one on top of the other and are electrically separated from one another by a thin insulating foil 14 . This virtually prevents generation of disturbing magnetic fields when a current flows through the heating coil 13 .
[0091] Copper or aluminium would be suitable materials for the layers 13 , 13 ″. Al 2 O 3 would be suitable for the insulating layer 14 . An arrangement of this type can also consist of a combination of different materials for the layers 13 ′ and 13 ″ wherein same should be selected such that the overall heating coil 13 is magnetically compensated towards the outside.
[0092] Suitable orientation of the tempering means 11 with respect to the most sensitive RF receiver coils used minimizes electromagnetic coupling with the RF receiver coil system 1 .
[0093] To minimize signal distortion, disturbing signals and residual attenuation, the electrically heated variant of the inventive tempering means 11 should be provided with a low-pass filter 15 upstream of the corresponding heating coils 12 (see FIG. 8 a ).
[0094] [0094]FIG. 8 b schematically shows a further improved embodiment wherein an electric rejector circuit 16 , 16 ′ is connected upstream of the two inputs of the heating coil 12 which blocks the RF frequencies which are to be measured and which additionally minimizes the influence of the heating current on the NMR measurement such as distortion and attenuation of the measuring frequencies. When an alternating current is used as heating current through the heating coil 12 , the angular frequency of the alternating current can be selected such that the sidebands generated thereby are outside of the observeable NMR spectrum.
[0095] The heating efficiency can be permanently set in accordance with the expected radial heat flow at a temperature T IN of the tempering gas 8 flowing into the room temperature pipe 4 from the bottom, and be corrected in proportion to the fourth power of that temperature.
[0096] Other embodiments permit active regulation of the heating power. For this purpose, two thermometers 17 , 17 ′ at the lower and upper ends of the inner pipe 5 of the room temperature pipe 4 can measure the prevailing temperatures T 1 or T 2 and supply same to an electronic control circuit 18 which controls the tempering means 11 . In the most simple case, the control circuit 18 may consist of a differential amplifier 18 ′ which receives the two temperature signals of the thermometers 17 , 17 ′ and passes its differential signal on to a regulator 18 ″ which controls a final step 18 ′″ which in turn supplies the tempering means 11 , in particular a heating coil 12 with corresponding heating current.
[0097] The embodiment of the NMR probe head in accordance with the invention schematically shown in FIG. 10 a comprises an RF receiver coil system 1 which is disposed symmetrically, with respect to a z axis, about an axially extending room temperature pipe 4 which serves for accommodating a sample tube 6 containing a sample substance 7 to be examined by NMR measurements.
[0098] The RF receiver coil system 1 is mounted onto heat conducting elements 2 which cool the RF receiver coil system 1 to cryogenic temperatures, usually T i ≈25 K.
[0099] The upper and lower sections of the room temperature pipe 4 are connected to a casing 3 of the NMR probe head whereas its central section comprises an inner pipe 5 (mainly of glass) which is permeable to RF fields. The sample tube 6 , axially projecting into the room temperature pipe 4 , is held at the desired temperature during the measurements by means of a gas flow 8 which is tempered approximately to room temperature T 2 ≈300 K.
[0100] [0100]FIGS. 10 a and 10 b clearly show that several radiation shields 9 are disposed between the receiver coil system 1 and the room temperature pipe 4 surrounding the room temperature pipe 4 in a radial direction and extending along the z axis. The radiation shields 9 are formed of materials oriented in the z direction which are almost completely transparent to RF fields. The radiation shields 9 are separated from each other in the radial direction and do not contact another or, at the most, have point or linear contacts, as clearly shown in FIG. 1 b . They have a radial thickness <0.1 mm, preferably <50 μm. The radiation shields 9 are preferably made from glass or quartz.
[0101] To obtain orientation of the material in the z direction as required by the invention, the radiation shields 9 may be formed of a unidirectional foil, of unidirectional fabric, in particular of fiber glass mats, or of axially extending rods or fibers, preferably glass or quartz fibers or fiber bundles.
[0102] The radiation shields 9 may be freely disposed in space and mounted only at their ends or, as shown in the embodiment, mounted to the room temperature pipe 4 .
[0103] For reasons of clarity, FIGS. 10 a and 10 b do not show the centering device in accordance with the invention. It can be incorporated as any of the embodiments described above.
[0104] [0104]FIGS. 11 a and 11 b finally show a preferred embodiment of the inventive NMR probe head comprising a centering means having, in the embodiment shown, four spacers 10 symmetrically distributed about the z axis. The associated proper centering of the sample tube 6 within the room temperature pipe 4 prevents convection flow and thereby formation of temperature gradients within the sample substance 7 , as already explained above.
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An NMR (=nuclear magnetic resonance) probe head comprising an RF (=radio frequency) receiver coil system, which can be cooled down to cryogenic temperatures, and a room temperature pipe (5), extending in a z direction, for receiving a sample tube containing sample substance to be examined by NMR measurements is characterized in that a tempering means (11) is disposed between the RF receiver coil system and the sample tube which surrounds the sample tube in a radial direction and extends in the z direction and is almost completely transparent to RF fields, or at least has an absorption of <5%, preferably <1% for RF fields to thereby provide simple and substantial reduction in the temperature gradient in the z direction during operation without thereby impairing the NMR measurement.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application Ser. No. 60/319,849, filed Jan. 10, 2003, which is incorporated herein in its entirety, and is a continuation in part of U.S. patent application Ser. No. 10/249,113, filed Mar. 17, 2003 now abandoned, a continuation in part of Ser. No. 09/849,143, filed May 4, 2001 now abandoned, which claims the benefit of U.S. Provisional Application 60/201,933, filed May 5, 2000 and U.S. Provisional Application 60/269,044, filed Feb. 15, 2001, all of which are incorporated herein in their entirety.
BACKGROUND OF INVENTION
1. Field of the Invention
This invention relates to a multi-use vacuum cleaner, and, more particularly, to a vacuum cleaner having a vacuum module comprising a cyclonic dirt separator which is detachably mounted to a power foot and upright support member.
2. Description of the Related Art
A multi-use vacuum cleaner capable for use as an upright vacuum or as a detachable vacuum module is disclosed in U.S. Pat. No. 5,524,321 to Weaver et al., issued Jun. 11, 1996 and U.S. Pat. No. 5,309,600 to Weaver et al. issued May 10, 1994. A detachable vacuum module is selectively mounted to the foot and support member of an upright vacuum cleaner. The vacuum module includes the vacuum motor, motor driven fan, vacuum bag and hose. The vacuum cleaner may be operated as an upright vacuum, or alternatively, the module can be separated from the foot and upright support member to be used independently of and at a great distance from the foot and upright support member for a wide variety of cleaning purposes.
The U.S. Patent Application Publication No. US2002/0011050 to Hansen et al., published Jan. 31, 2002, discloses a suction cleaner with a cyclonic dirt separator comprising a dirt collection assembly including a cyclonic separator having an inlet aperture and an outlet aperture, and a suction source fluidly connected with the cyclonic separator. In one embodiment, the cyclonic dirt separator includes a separator plate cooperating with the housing to separate the cyclonic separator from a dirt collecting cup. The separator plate has an outer diameter smaller than the inner diameter of the dirt tank, creating a gap between the outer edge of the separator plate and the inner wall of the cyclonic separator.
SUMMARY OF INVENTION
According to the invention, a multi-use upright vacuum cleaner combines the ease of use and compact configuration of an upright vacuum cleaner with the portability and multiple applications of a canister vacuum wherein the main filtration is accomplished with a cyclonic dirt separator. The vacuum cleaner has a foot assembly having a suction nozzle and adapted to move along a surface to be cleaned, an upright handle assembly pivotally mounted to the foot assembly for manipulation of the foot assembly along the surface to be cleaned.
The handle assembly includes a module platform pivotally mounted to the foot assembly, an elongated structural support, and a portable cleaning module. The elongated structural support is rigidly mounted at a lower portion to the module platform and forms a handle grip at an upper portion. The portable cleaning module is detachably mounted as a unit to the module platform and includes a module housing, a dirt separator mounted in the module housing for separating dust and dirt from dirt laden air, a suction conduit having a first end connected to the module housing in fluid communication with the dirt separator and a second with a removable coupling. A motor-driven fan is supported in the module housing for creating suction within the suction conduit and for moving the dirt laden air through the dirt separator.
A working air conduit is connected at a first end to the suction nozzle in the foot assembly and is removably connected at another end to the suction conduit removable coupling. When the portable cleaning module is mounted on the module platform, the vacuum cleaner functions as an upright vacuum cleaner and the motor-driven fan draws dirt laden air from the suction nozzle in the foot assembly to the suction conduit and moves the dirt laden air to the dirt separator for separation of dirt from air. When the portable cleaning module is removed from the module platform, the portable vacuum module can function by itself as a portable vacuum cleaner and the motor-driven fan draws dirt laden air from the second end of the suction conduit and moves the dirt laden air to the dirt separator for separation of dirt from air.
According to the invention, the dirt separator includes a cyclone separation chamber into which the dirt laden air is tangentially introduced through an inlet thereto.
In a preferred embodiment of the invention, the elongated structural support comprises a pair of spaced elongated frames that are joined at upper portions thereof and the portable cleaning module is positioned between the spaced elongated frames when it is mounted on the module platform. Preferably, the spaced elongated frames form a handle grip at an upper portion thereof. In addition, the spaced elongated frames are tubes.
Typically, the suction conduit is at least in part flexible for movement of the second end thereof with respect to the module housing during use of the portable cleaning module when it is detached from the module platform. Cleaning tools, carried by the elongated structural support can be mounted on the second end of the suction conduit when the portable cleaning module is detached from the module platform. In one embodiment, the other end of the working air conduit is integrated into the module platform and is formed by an opening in the module platform. The suction conduit removable coupling is removably mounted to the opening in the module platform.
In one embodiment, the cyclone separation chamber has an outlet and the motor driven fan has an inlet connected to the cyclone separator chamber outlet. In another embodiment, the motor driven fan has an inlet connected to the first end of the suction conduit and an outlet connected to the cyclone separator chamber inlet.
Typically, the dirt separator further includes a dirt cup removably mounted in the module housing beneath the cyclone separator to collect dirt separated from air therein. Further, the module housing further includes a handle integrally formed at an upper portion thereof for carrying the portable cleaning module when it is detached from the module platform.
In one embodiment, the portable cleaning module has a handle, preferably at an upper portion thereof, for hand carrying the cleaning module.
BRIEF DESCRIPTION OF DRAWINGS
In the drawings:
FIG. 1 is a perspective view of the multi-use vacuum cleaner having a detachable vacuum module with cyclonic dirt separation.
FIG. 2 is a rear quarter perspective view of the vacuum module separated from the upright vacuum cleaner foot assembly.
FIG. 3 is a partial sectional view of the vacuum module and foot assembly taken along lines 3 — 3 of FIG. 1 .
FIG. 4 is a front cross sectional view of the cyclonic separator for a vacuum module as shown in FIG. 1 .
FIG. 5 is a perspective view of the multi-use vacuum cleaner of FIG. 1 with the dirt cup removed.
FIG. 6 is a schematic view of an alternative embodiment of the module illustrated in FIGS. 1–5 according to the invention.
DETAILED DESCRIPTION
With reference to FIGS. 1 and 2 , an upright vacuum cleaner 10 comprises an upright handle assembly 12 and a foot assembly 14 . The upright handle assemble 12 comprises a module platform 24 , an elongated structural support 19 and a detachable cyclonic vacuum module 16 . The elongated structural support 19 is formed by a pair of spaced apart elongated frames in the form of support tubes 20 that are joined to form a grip 18 at an upper portion thereof. The support tubes 20 merge in an arc-like configuration at an upper end of the support tubes 20 and merge into the grip 18 . A mechanical stop 22 is positioned approximately midway between a lower end of each support tube 20 and the arc-like configuration. The stop 22 is a block-like structure to provide lateral support for the detachable cyclonic vacuum module 16 . The module platform 24 is rigidly attached to the lower ends of the support tubes 20 in a generally perpendicular fashion. Wheel axle bearings (not shown) extend through the first end of the support tube 20 in a horizontal direction. The upright handle assembly 12 including the module platform 24 rotates about the wheel axle bearings. An upholstery tool 26 is removably attached to a recessed upholstery tool caddy 28 located on an upper rearward surface of the upright handle assembly 12 .
Referring to FIGS. 1 , 2 and 3 , the foot assembly 14 further comprises a foot housing 30 , a wheel 32 , a brush chamber 34 , and a working air path described in more detail below. The brush chamber 34 comprises a cavity formed horizontally at a forward section of the foot housing 30 . Brush chamber 34 further comprises a brush 36 . Brush 36 is a generally well known horizontal brush roll that is driven by a separate brush motor (not shown) located within the foot housing 30 . An electric switch (not shown) on the detachable cyclonic vacuum module 16 selectively supplies power to the brush motor. A wheel axle 38 passes through the wheel axle bearings in the support tubes 20 and is rigidly fixed to either side of the foot housing 30 . Wheel 32 is rotatably mounted to axle 38 .
Referring to FIG. 3 , the working air path comprises a suction nozzle aperture 40 , a flexible working air conduit 42 , and an air conduit interface 44 . Suction nozzle aperture 40 is formed on a lower surface of brush chamber 34 . Space between the brush 36 and the brush chamber 34 allow air to pass through brush chamber 34 . Flexible working air conduit 42 is fluidly connected to suction nozzle 40 on one end, is routed through a lower portion of the foot housing 30 and terminates at the air conduit interface 44 on an upper rearward surface of the foot housing 30 . Thus, an uninterrupted air path is created through the foot housing from the suction nozzle 40 to the air conduit interface 44 . A more complete description of a suitable foot assembly 14 and of a suitable mounting between the module platform 24 and the detachable module 16 is disclosed in U.S. Pat. Nos. 5,524,321 and 5,309,600 to Weaver et al., which are incorporated herein by reference in their entirety.
Referring to FIGS. 1 , 2 and 3 , the detachable cyclonic vacuum module 16 further comprises a module housing 46 , a cyclonic separator 48 , a removable dirt cup 50 , a dirt cup latch 52 , a filter tray assembly 54 , fan chamber 56 , an external hose 58 and an outlet air conduit 60 . The module housing 46 provides structure for the detachable cyclonic vacuum module 16 . Cavities are formed within the module housing 46 to support the cyclonic separator 48 , the removable dirt cup 50 , and the fan chamber 56 . A handle 62 is integrally formed in at an upper surface of the module housing 46 . Handle 62 provides a convenient location for a user to grasp and lift the detachable cyclonic vacuum module 16 . The external hose 58 has at one end a hose fitting 94 that is removably received in air conduit interface 44 and the other end is connected to cyclone air inlet aperature 78 .
Referring to FIG. 3 , a fan motor assembly 64 further comprises a fan 66 and a motor 68 . Fan motor assembly 64 is located vertically within the fan chamber 56 . Fan 66 further comprises a fan air inlet 70 and a plurality of working air exhaust apertures 71 . Optionally, a post motor filter can be placed in the working air exhaust between the fan motor assembly 64 and the exhaust apertures 71 . Filter tray 54 is a generally box like structure with solid side-walls supported by a framework structure to create a permeable floor. Filter tray 54 is removably inserted into a corresponding cavity in the module housing 46 between the fan chamber 56 and the dirt cup latch 52 . A permeable foam filter 72 fits within the perimeter of the filter tray 54 and is supported by the filter tray floor. Foam filter 72 is air permeable so that the air passes through the topside of the foam filter, through the foam filter, and exits the bottom side of the foam filter adjacent to the fan inlet 70 . Foam filter 72 removes fine particles from the airstream prior to the airstream entering the fan inlet 70 .
Referring to FIG. 5 , dirt cup latch 52 comprises a lever that rotates about a center axis inline with the fan motor assembly 64 . A pair of mating ramps raise and lower an upper surface of the dirt cup latch 52 as the dirt cup latch is moved from side to side. Removable dirt cup 50 is supported by an upper surface of the dirt cup latch 52 in a cavity 96 in the module 16 . As dirt cup latch 52 is moved to the lower setting, the removable dirt cup 50 moves down separating from the cyclonic separator 48 and allows the dirt cup 50 to be removed from the detachable cyclonic vacuum module 16 . One commercially available embodiment of the dirt cup latch is found in the Clean-View Model 3591 bagless upright vacuum cleaner sold by BISSELL Homecare, Inc.
Referring to FIGS. 3 and 4 , cyclonic separator 48 comprises a cylindrical sidewall 74 , a circular upper wall 76 and a cyclone air inlet aperture 78 . Circular upper wall 76 further comprises an exhaust outlet 80 comprising a centrally located aperture therethrough. A collar 82 depends from a lower surface of upper wall 76 . A separator plate 84 in the form of a solid disk having an upstanding annular collar 86 is located in spaced relation below the upper wall 76 . In the preferred embodiment, the upstanding annular collar 86 is aligned with the depending collar 82 of the upper wall 76 . A cylindrical screen 88 is retained at the ends thereof by each of the collars 82 , 80 . In this manner, separator plate 84 is suspended from upper wall 76 , forming a toroidal chamber 90 between the cylindrical screen 88 and the side wall 74 , and between the upper wall 76 and the separator plate 84 , respectively. In the preferred embodiment, air inlet aperture 78 is vertically aligned between upper wall 76 and separator plate 84 such that tangential airflow generated from air inlet aperture 78 is directed into the toroidal chamber 90 .
With further reference to FIGS. 3 and 4 , the tangential air-flow containing particulate matter passes through the inlet air aperture 78 and into toroidal chamber 90 and travels around the cylindrical screen 88 . As the air travels about the toroidal chamber 90 , heavier dirt particles are forced toward sidewall 74 . These particles fall under the force of gravity through a gap 92 defined between an edge of separator plate 84 and the sidewall 74 . Referring particularly to FIG. 4 , dirt particles falling through the gap 92 drop through and are collected in the dirt cup 50 . The upper end of the dirt cup 50 is received in a nesting relationship to the side wall 74 to seal the dirt cup 50 with the cyclone separator 48 . As the working inlet air traverses through toroidal chamber 90 , casting dirt particles towards sidewall 74 , the inlet working air is drawn through cylindrical screen 88 , through exhaust outlet 80 , and into an outlet air conduit 60 . Outlet air conduit 60 is integrally molded in a rear wall of module housing 46 . Air moves through outlet air conduit 60 to the pre-motor filter 72 . Pre-motor filter 72 removes additional particulate matter from the exhaust airstreams prior to the airstreams being drawn through the fan motor assembly 64 . A post-motor filter 71 can also be provided downstream of the fan motor assembly 64 to remove additional fine particulate matter from the exhaust airstream before it is released to the atmosphere. An example of a suction cleaner with cyclonic dirt separation may be found in U.S. Patent Application Publication No. US2002/0011050 to Hansen et al. and is incorporated herein by reference in its entirety.
All of the elements that create suction are contained within the cyclonic vacuum module 48 . When the detachable cyclonic vacuum module 16 is attached to the upright handle assembly 12 the device may be operated as an ordinary upright vacuum cleaner. When power is applied to the fan motor assembly 64 , fan 66 turns creating an airflow. Suction is created at suction nozzle 40 thus drawing debris into the working air path. Dirt laden air continues to flow through the working air conduit 40 into hose 58 through inlet air aperture 78 whereby the dirt laden air is forced to rotate within the cyclonic separator 48 , thus separating the dirt from the air. Clean air then passes through cylindrical screen 88 through exhaust outlet 80 , through outlet air conduit 60 and into fan chamber 56 as previously described. With the detachable cyclonic vacuum module 16 detached from the upright handle assembly 12 , the flexible hose 58 hose fitting 94 can be removed from the air coupling interface 44 . Thus the user can attach the upholstery tool 26 to the hose fitting 94 , and utilize the detachable cyclonic vacuum module 16 as an effective portable upholstery cleaning device.
Referring now to FIG. 6 where like numerals have been used to describe like parts, a detachable cyclone cleaning module 100 includes a module housing 102 , a cyclone separation chamber 104 formed within the module housing 102 , a flexible suction conduit 110 and a motor driven fan 66 . The cyclone separation chamber has an inlet opening 106 and an outlet opening 108 . The flexible suction conduit 110 has a first end 112 connected to the housing and a second end 114 with hose coupling 94 that is adapted to mount into the module platform suction opening when the cleaning module is mounted to the module platform 24 ( FIGS. 1–3 ) and is freely movable when the cleaning module is removed from the module platform 24 . The motor driven fan 66 has an inlet opening 118 that is connected to the suction conduit first end 112 and an outlet opening 116 that is connected to the inlet 106 to the cyclone separation chamber 104 . The outlet to the cyclone separation chamber 104 is connected to a filter to remove remaining dirt and dust fines that are not separated from the air in the cyclone separation chamber 104 . A dirt cup 124 is mounted in the module housing beneath the cyclone separation chamber to collect dirt and dust separated from the air in the cyclone separation chamber.
While the invention has been specifically described in connection with certain embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the forgoing description and drawings without departing from the spirit of the invention, which is described in the appended claims.
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A multi-use vacuum cleaner capable of use as an upright vacuum or as a detachable vacuum module further comprising a cyclonic dirt separator has a detachable vacuum module selectively mounted to the base and support member of an upright vacuum cleaner. The vacuum module includes the vacuum motor, motor driven fan, cyclonic dirt separator and hose. The vacuum cleaner may be operated as an upright vacuum, or alternatively, the module can be separated from the base assembly and may be used independently of and at a great distance from the base assembly for a wide variety of cleaning purposes.
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BACKGROUND
The follows generally relates to auto hammers and, more specifically, to an auto hammer with a clamping mechanism.
In the fitment and decoration fields, the auto hammer is a commonly used tool. For example, Chinese patent application No. 200820161342.1 discloses an auto hammer, which comprises a housing and a nozzle portion connected to the housing. The nozzle portion is generally formed of a hollow cylindrical sleeve. A hole for receiving a magnet is drilled in the sleeve, and the magnet engages into the hole so as to attract a nail arranged in the striking device for clamping the nail. The disadvantages of this auto hammer are: the magnet is arranged on the edge of the sleeve, thus the nail cannot be located in the centre of the sleeve and cannot be positioned parallel to the centre line of the sleeve (that is to say, the nail is inclined after being attracted), and the magnet cannot clamp other non-magnetic materials, for example, wooden tenons and the like.
SUMMARY
The following describes an auto hammer improved to overcome the problems existing in the prior art, particularly to provide an auto hammer wherein the nail or other elements can be firmly clamped in the striking device, so that it is convenient for users.
To this end, an auto hammer with simple manipulation, good visibility and compact structure is provided, which comprises a striking device with a clamping mechanism. The clamping mechanism comprises at least one clamping member, a driving part and a sliding member, wherein at least one clamping member is pivotally arranged in the sliding member and connected to the driving part, and the driving part can rotate relative to the sliding member so as to cause the clamping member to rotate pivotally in the sliding member. The clamping member can grip a nail in a larger area, so that a good effect for gripping may be obtained.
Further, the sliding member is provided with an inclined slot and a pin passes through the inclined slot and the driving part and moves along the inclined slot.
Further, the clamping member can be any one or any combination of elements in the group consisting of a chuck jaw, spring, magnet, bolt and chuck for retaining an element.
Further, the striking device also has a striking rod and a releasing area is formed when the clamping member is located at the opened position such that the striking rod may pass through the releasing area.
Further, the clamping mechanism comprises a bush and a bracket and the bush may engage with the bracket.
Further, the clamping mechanism comprises a first biasing device for biasing the sliding member towards the workpiece.
Further, the clamping mechanism comprises a second biasing device for biasing the bush towards the workpiece.
Further, the clamping mechanism comprises three clamping members and each paired set of clamping members can be interlocked with each other.
Further, the clamping mechanism comprises a locking mechanism including a projection and a spanner, wherein the clamping members are located at the opened position when the projection is locked with the spanner, and the striking rod is emerged out of the sliding member when the projection is locked with the spanner at another position.
Further, the sliding member is made of transparent material.
Further, the striking rod applies a striking force to the element to move it, and a transmitting mechanism is used to convert the rotational motion of a motor into the liner reciprocating motion of the striking rod.
Further, the striking rod may strike the element many times so that the element can be gradually inserted into the workpiece.
Further, the transmitting mechanism comprises an impact wheel with at least one projection, and the projection may apply a periodically impact motion to the striking rod.
BRIEF DESCRIPTION OF THE DRAWINGS
Detailed embodiments of the subject auto hammer are described below in conjunction with the attached drawings in which:
FIG. 1 is a perspective view illustrating an auto hammer according to one embodiment of the present invention;
FIG. 2 is a sectional view of the auto hammer in FIG. 1 taken along the combination surface of the two housing halves;
FIG. 3 is a sectional view of the auto hammer in FIG. 1 taken along a surface which is vertical to the combination surface of the two housing halves;
FIG. 4 is a partial exploded view of a transmitting device of the auto hammer in FIG. 1 ;
FIG. 5 is a sectional view of the auto hammer in FIG. 2 taken along the axial line A-A;
FIG. 6 is a perspective view of a clamping mechanism of the auto hammer in FIG. 1 , wherein the clamping members are located at the closed position;
FIG. 7 is a sectional view of the clamping mechanism in FIG. 6 taken along the combination surface of the two housing halves;
FIG. 8 is a perspective view of the clamping mechanism of the auto hammer in FIG. 1 , wherein the clamping members are located at the opened position;
FIG. 9 is a sectional view of the clamping mechanism in FIG. 8 taken along the combination surface of the two housing halves;
FIG. 10 is a left view of the clamping mechanism in FIG. 6 ;
FIG. 11 is a left view of the clamping mechanism in FIG. 8 ;
FIG. 12 is a view illustrating the auto hammer in FIG. 1 positioned on the workpiece;
FIG. 13 is a view illustrating the bracket of the clamping mechanism of the auto hammer in FIG. 1 engaged with the workpiece;
FIG. 14 is a view illustrating a fastening element being completely inserted into the workpiece; and
FIG. 15 is a view illustrating the striking rod emerged out of the sliding member.
DETAILED DESCRIPTION
As shown in FIGS. 1-4 , the auto hammer 1 of the present embodiment comprises a housing 2 which accommodates a motor M therein and a striking device 6 . The housing 2 is composed of two housing halves, i.e., the left and right half housings 2 ′ and 2 ″. The main body of the housing 2 forms a substantially vertical grip portion 4 , and the housing 2 comprises a head assembly 3 on its upper end. The head assembly comprises a transmission mechanism and the striking device 6 .
In this exemplary embodiment, the auto hammer 1 has a battery pack (not shown) for supplying power to the motor M. However, the auto hammer need not be restricted to the use of a DC power supply and may be equally powered by a source of AC power. A switch 7 is arranged on the housing 2 for controlling the motor (not shown). The striking device 6 comprises a striking rod 61 which is substantially horizontal as illustrated and arranged in the striking device 6 by a spring and which can move in linear reciprocating manner therein. During operation, the end surface of the striking end 611 of the striking rod 61 may act on elements, for example, fasteners such as nails or wooden tenons or objects such as bricks. The striking device 6 also has a receiving cavity 63 that is designed as a retractable configuration and may contact the surface of the workpiece to be processed. Furthermore, the receiving cavity 63 has a larger inner diameter than a general fastener so that fasteners with different sizes may be positioned into the receiving cavity.
As shown in FIGS. 3-4 , a rotary-linear movement transmission mechanism is arranged in the housing 2 for converting the rotational movement of the motor M into the impacting movement of the striking rod 61 . The motor M is vertically arranged in the housing 2 as illustrated. The upward motor shaft X′ thereof transmits the rotation power of the motor M to a rotating shaft 35 by means of a multistage gear transmission including bevel gears. The rotating shaft 35 is supported on the upper portion of the housing by bearings on two ends. The rotating shaft 35 is provided with a pair of inclined slots 36 , and each of the inclined slots 36 is formed with a general “V” shape which opens backwards. An impact wheel 31 surrounds the rotating shaft 35 and is generally a hollow cylinder, with a pair of circular-arc guiding slots 37 arranged in the inner cylindrical surface thereof and opposite to the two inclined slots 36 respectively. The bottoms of the inclined slots 36 and the guiding slots 37 are provided with a semi-circular-arc. A pair of steel balls 38 are respectively positioned in the chambers formed between the inclined slots 36 and the guiding slots 37 , and the steel balls 38 may move relatively along the inclined slots 36 and the guiding slots 37 . Thus, when the rotating shaft 35 rotates, the impact wheel 31 may be driven to rotate by the steel balls 38 in the inclined slots 36 . A pair of projections 32 , which projections are disposed oppositely along the diameter direction of the impact wheel 31 , is provided on the outer circumference of the impact wheel 31 . After turning on the switch 7 , the motor M is powered to drive the rotating shaft 35 to rotate by the multistage gear transmission, and then the impact wheel 31 is driven to rotate together therewith by the steel balls 38 .
As shown in FIG. 4 , an energy storing spring 40 is arranged between the impact wheel 31 and the rotating shaft 35 in such a manner that one end of the energy storing spring 40 bears against the shoulder 351 of the rotating shaft 35 and the other end bears against the impact wheel 31 . With the axial force of the energy storing spring 40 , the impact wheel 31 is located in a first axial position relative to the rotating shaft 35 . In the first axial position, the impact wheel 31 moves in a circle under the action of the rotating shaft 35 and steel balls 38 . When the impact wheel 31 rotates to a position where the projection 32 may contact the striking rod 61 , the striking rod 61 encounters a large resistance force that cannot be overcome for the moment, thus the striking rod 61 stops the impact wheel 31 rotating temporarily, and then the impact wheel 31 gradually compresses the energy storing spring 40 and moves from the first axial position to a second axial position. In the second axial position, the projection 32 of the impact wheel 31 departs from the striking rod 61 , and the stopping energy is released, i.e., the energy storing spring 40 starts to release its elastic potential energy. Under a function of the rebound axial force of the energy storing spring 40 , the impact wheel 31 is pressed back to the first position, and is moved at a higher speed than that of the rotating shaft 35 with the cooperation of the inclined slots 36 , the guiding slots 37 and the steel balls 38 . As a result, the projection 32 of the impact wheel 31 impacts the stricken end 612 of the striking rod 61 , and the striking rod 61 moves at a high speed in a linear direction and thereby one impact is achieved. After the first impact is finished, the second impact cycle starts when the impact wheel 31 is driven to rotate to be stopped by the striking rod 61 again, and the next following impact process will be completed in the same manner.
As shown in FIGS. 2 , 5 and 6 , a clamping mechanism 5 is provided in the striking device 6 for clamping a nail or other fastening elements. The clamping mechanism 5 is in the form of clamping members 52 a , 52 b and 52 c . One end of each clamping member is pivotally arranged on the sliding member 8 and these clamping members are interlocked with each other, so that three clamping members can be opened or closed simultaneously. Each clamping member has two projections 521 and 522 , wherein the projection 521 is arranged in the bracket 9 and the projection 522 is arranged in the main body 51 . When the main body 51 rotates relative to the sliding member 8 , each clamping member rotates together with the main body. The clamping members 52 a , 52 b and 52 c have a first position, as shown in FIGS. 6 and 7 , where the three clamping members are closed upon each other to form a clamping area whereby the nail or other fastening elements can be engaged with the clamping members and retained in this area. The clamping members 52 a , 52 b and 52 c have a second position, as shown in FIGS. 8 and 9 , where the three clamping members are entirely opened with respect to each other to form a releasing area whereby the nail or other fastening elements can be disengaged from the clamping members, and the striking rod may pass through this releasing area to continuously strike the nail until the nail is completely nailed into the workpiece. When the clamping members are located at the second position (i.e., the completely opened position), the nail or other fastening elements can be placed in the receiving cavity 63 , and then the clamping members may be closed, thus the nail or other fastening elements may be retained in the clamping area. The clamping member is adjustable, so the nail or other elements with different sizes could be retained independently by the clamping members.
A person skilled in the art will understand that the clamping members may be any one or any combination of elements selected from a group consisting of a chuck jaw, spring, magnet, bolt and chuck for retaining elements.
As shown in FIGS. 1 , 2 , 6 and 7 , when assembled, a bush 10 may be movably nested on the striking rod 61 . The main body 51 as a driving part is movably arranged on a stationary bush 11 . The projections 522 of three clamping members are respectively arranged on the main body 51 . Then, the bracket 9 is installed on the projections 522 of three clamping members. Three grooves 8 a are provided in the sliding member 8 , and the angle between each two grooves is 120° in the circumference direction of the sliding member. One end of each clamping member is respectively arranged in each of the three grooves 8 a , so that the sliding member can slide relative to the clamping members in the grooves. The sliding member 8 is further provided with an inclined slot 12 and another inclined slot (not shown) in the position that rotates by 180° in the circumference direction of the sliding member. A pin 80 passes through the inclined slot 12 and is installed on the main body 51 . The pin 80 may slide relative to the inclined slot 12 , and with the sliding of the sliding member 8 , the pin 80 slides relative to the inclined slot 12 , thereby the main body 51 may be driven to rotate by the pin 80 relative to the sliding member 8 , and the rotation of the main body 51 can drive the clamping members installed thereon to rotate. As a result, three clamping members can be gradually opened until they rotate to the completely opened position. A projection 8 b is provided in the lower end of the sliding member 8 . After the nail is completely nailed into the workpiece, the sliding member 8 is locked, and the clamping members are located at the completely opened position at the moment.
A first biasing device is in the form of a spring 13 for biasing the sliding member 8 towards the workpiece, so that the clamping members are located at the closed position. One end of the spring 13 is installed on the sliding member 8 , and the other end is installed on the gearbox. When the sliding member 8 contacts the workpiece, the user has to overcome the pressure of the first biasing device to open the clamping members. A second biasing device is in the form of a spring 14 for biasing the bush 10 towards the workpiece. One end of the spring 14 is installed on the end of the bush 10 , and the other end is installed on the stationary bush 11 . When the bush 10 contacts the workpiece, the user has to overcome the pressure of the second biasing device. At this moment, the clamping members are completely opened, and the bush 10 may pass through the releasing area for preventing the nail from being blocked in any gap between the clamping members.
As shown in FIGS. 12 to 15 , during operation, if the clamping members are located at the closed position, the user has to overcome the pressure of the first biasing device 13 to push the sliding member 8 to move rightwards. The user may push the sliding member 8 directly, or push a spanner (not shown) provided on the housing 2 that engages with the sliding member, so as to overcome the spring force to open the clamping members, and the nail may be positioned in the receiving cavity 63 . The clamping mechanism 5 also has a locking mechanism in the form of a projection 8 b provided in the lower end of the sliding member. When the projection 8 b is locked with the spanner, the clamping members are located at the opened position, then the spanner 15 is released and the nail can be retained independently by the clamping members, subsequently, the auto hammer is positioned in this way that the nail is adjacent to the workpiece, as shown in FIG. 12 . Then the switch 7 is pressed to power the motor M and cause the striking rod 61 to move in a reciprocating manner. When the user pushes the auto hammer to the workpiece, the head of the nail is struck by the striking rod continuously so that the nail may be inserted into the workpiece gradually. During the gradually insertion of the nail, the user has to overcome the pressure of the spring 13 to open the clamping members when the sliding member 8 engages with the workpiece. This allows the nail to be partially inserted into the workpiece before being released. As shown in FIG. 13 , when the end surface of the bracket 9 contacts the workpiece, the clamping members are located at the completely opened position, the sliding member 8 moves together with the main body 51 rightwards, and the projection 8 b of the sliding member 8 pushes out the spanner 15 such that the sliding member 8 continues to move rightward. When the bush 10 contacts the bracket 9 , the user has to overcome the pressure of the spring 14 to ensure that the bush 10 is always near the head of the nail so as to prevent the head of the nail being blocked in the gap formed between the clamping members located at the completely opened position. Then, the nail is struck continuously until the nail is completely inserted into the workpiece.
After the nail is completely inserted into the workpiece, the sliding member 8 is locked in the position where the clamping members are completely opened. Subsequently, another nail can be placed in the receiving cavity 63 , and the spanner 15 is pressed such that the clamping members clamp the nail in the receiving cavity 63 , and the above steps may be repeated for secondly striking the nail. In the locking mechanism of the clamping mechanism 5 , the projection 8 b in the lower end of the sliding member 8 may lock the sliding member 8 in another position, where the striking rod 61 is emerged out of the sliding member 8 such that the visibility of the striking rod 61 is enhanced. At that moment, the striking end 611 of the striking rod 61 may be used as the knocking part of the auto hammer for knocking the workpiece to be processed during the operation with the liner reciprocating movement of the striking rod 61 , for example, knocking a tenon or a brick or the like, thus the functions of the device may be extended without limiting the function of the device to driving fasteners into a workpiece. In accordance with the present embodiment, the person skilled in the art could conceive that the sliding member 8 may be formed of transparent materials, such as transparent plastic, which may also enhance the visibility of the striking rod 61 . When the user observes the specific position of the striking rod 61 , he may use it as an auto hammer to knock the workpiece to be processed.
In conclusion, the auto hammer disclosed herein is not to be restricted to the described embodiments or the constructions shown in the drawings. Rather, any changes, substitutes and modifications in the configurations and positions of the components described and illustrated according to the spirit of the present invention will be regarded as falling within the range of the claims which follow.
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An auto hammer has a housing, a grip portion and a striking device. The striking device has a striking rod that can strike a fastening element using a liner reciprocating motion. The striking device also has an associated clamping mechanism for clamping the fastening element. The clamping mechanism includes a clamping member, a driving part and a sliding member, wherein the clamping member is pivotally arranged in the sliding member and is connected to the driving part, and the driving part can rotate relative to the sliding member so as to cause the clamping member to rotate pivotally in the sliding member. The clamping mechanism may thus firmly clamp the fastening element in a manner that is convenient for users.
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BACKGROUND OF THE INVENTION
The present invention relates to gas and steam turbines and, more particularly, to apparatus for improving the cooling in vanes or buckets of turbines.
The Carnot efficiency of a heat engine is limited by, along other parameters, the maximum temperature of the working fluid fed to it. Relatively small increases in working fluid temperature can result in substantial efficiency increases. The temperature which is used is limited by the ability of materials in the apparatus to withstand the temperature and continue to function without melting or other forms of destruction. Early attempts to increase the working temperature included the use of metals having superior strength and toughness at elevated temperatures near their melting points. A limit is reached even in so-called super alloys at about twelve to fourteen hundred degrees F. beyond which the material will fail.
Gas and steam turbines represent one type of heat engine in which increasing the working temperature by a relatively small amount results in a relatively large improvement in efficiency. In a gas or a steam turbine, the working fluid (super heated steam or heated air and products of combustion) is directed against blades or buckets of one or more turbine stages to rotate the blades or buckets for delivering power to a shaft. In order to maximize the power derived from the working fluid, it is directed to the first stage turbine through nozzles which are formed between adjacent aerodynamically shaped blades which turn and accelerate the working fluid for impingement on the blades or buckets. Additional nozzles may be employed between subsequent turbine stages to accept the working fluid from the preceding stage, turn, direct and accelerate it for impingement on the next downstream stage. As the working fluid gives up energy to the turbine, it expands and its temperature reduces.
The first one or two stages of vanes forming nozzles thus receive the hottest working fluid and their ability to tolerate high temperatures provides the effective limit to the overall efficiency of the turbine.
One of the techniques employed in the prior art includes active cooling of critical parts employing cooling gas or liquid. For example, U.S. Pat. Nos. 4,244,676; 3,804,551; 4,017,210 and British Pat. No. 641,146 employ cooling flow of liquid or gas in radial passages in turbine blades. U.S. Pat. No. 3,706,508 accomplishes substantially the same result using radial passages in vanes defining turbine nozzles.
A different approach employs coring or hollowing the interior of stator vanes and flowing a cooling gas such as air therein for carrying off the heat. In order to improve the cooling still further, a sheet metal impingement insert may be inserted into the hollow core with holes or other openings directing cooling air at the inner surface of the vane for further improving of cooling. A problem may arise in such cored vanes in the aft end of the hollowed portion. Hot spots may develop on the exterior due to the fact that the cored portion is necessarily quite narrow in this region and it is difficult to properly direct and control cooling air.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a cooling apparatus for a nozzle vane or turbine bucket which overcomes the drawbacks of the prior art.
It is a further object of the invention to provide improved cooling in the aft portion of the cored vane or turbine bucket.
It is a further object of the invention to provide a baffle means in the aft end of a turbine bucket which tends to accelerate the air flow past the interior of the vane or bucket for improving cooling in a specific location.
According to a feature of the invention, apparatus is provided for modifying cooling fluid flow in a cored member comprising a hollow core portion defining a wall effective for impinging a cooling fluid against a first inside portion of the wall, a plurality of channels effective to exhaust the cooling fluid from the hollow cored portion, a flow control body interposed between the first inside portion and the channels, and the flow control body including means for modifying a flow of the cooling fluid adjacent a second inside portion of the wall whereby cooling uniformity is enhanced.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross sectional view of a gas turbine for illustrating the environment in which the present invention is employed.
FIG. 2 is a cross sectional view of a cored vane including an impingement insert according to the prior art.
FIG. 3 is a close-up cross sectional view of a portion of a vane including a flow control body according to an embodiment of the present invention.
FIG. 4 is a side view of the flow control body of FIG. 3.
FIG. 5 is a perspective view partially cut away of a vane including a flow control body of FIGS. 3 and 4.
FIG. 6 is a cross sectional view of a portion of a vane including a flow control body which improves the positioning of local cooling with respect to hot spots.
FIG. 7 is an embodiment of the invention in which the flow control body includes turbulence chambers for positioning points of maximum cooling.
FIG. 8 is a side view of a portion of a flow control body showing a groove having vertically displaced inlet and outlet portions with a turbulence chamber between them.
FIG. 9 is a side view of a flow control body having a tapering shape to more closely fit the tapering shape of a hollow core in a vane.
FIG. 10 is a side view of a flow control body in which at least one parameter is changed from center to end to vary the cooling capability.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Although the present invention may be equally useful in stationary vanes and in rotating buckets of a gas or steam turbine, for concreteness of description, a particular embodiment is described adapted for use in a stator vane of a gas turbine engine.
Referring now to FIG. 1, there is shown, generally at 10, a cross section of a portion of a gas turbine engine. Hot air and products of combustion enter as shown by an arrow 12 passing through an annular set of nozzles formed between a plurality of vanes 14. Vanes 14 turn, direct and accelerate the gas mixture for impingement upon turbine blades or buckets 16 which impart rotary motion to a shaft 18. Subsequent stages of vanes and turbine blades may be employed as is conventional for extracting additional heat from the hot gas and the expanded and cooled gas is exhausted as indicated by an arrow 20.
Referring now to FIG. 2, a cross section is shown of a vane 14 according to the prior art. A hollow core 22, preferably formed during casting of vane 14 leaves a relatively thin wall 24 defining the aerodynamic shape of vane 14.
In order to direct cooling air, or other cooling gas, against an inside surface 26 of vane 14, an impingement insert 28 is positioned in hollow core 22 spaced preferably a uniform distance away from inside surface 26. Impingement insert 28 is preferably a closed sheet metal structure into which pressurized cooling air is delivered. A plurality of air delivery holes (not specifically shown in FIG. 2) direct jets of cooling air 30 upon inside surface 26 as indicated by arrows surrounding impingement insert 28. The cooling air in hollow core 22 between impingement insert 28 and inside surface 26 flows toward the trailing edge of vane 14 as indicated by arrows 32. This aft-traveling air cools inside surface 26 and exits through a plurality of trailing edge channels 34.
As indicated in FIG. 2, the aft end of hollow core 22 becomes quite narrow requiring that the aft end 36 of impingement insert 28 also be narrow. In such a narrow portion of impingement insert 28, proper direction of flow of jets 30 is a problem. Aft end 36 is terminated a relatively long distance forward of an entry 38 into trailing edge channels 34. A relatively wide portion 40 at the aft end of hollow core 22 permits the cooling air flowing backward toward trailing edge channels 34 to slow down and thus reduces its cooling capability on wall 24. Studies have indicated that hot spots 42 and 44 may develop in wall 24 in the vicinity of wide portion 40.
Referring now to FIG. 3, a flow control body 46 is disposed in wide portion 40 and contacting inside surface 26 at points 48 and 50. Referring now also to FIG. 4, flow control body 46 may be, for example, a metal rod having a plurality of lands 52 defining between them a plurality of grooves 54. Lands 52 provide the contact at points 48 and 50 with inside surface 26 while cooling air flows in the remaining channels provided by grooves 54. As a result of restricting the flow path in this way, the air flow velocity in the vicinity of inside surface 26 is increased as it passes through grooves 54. The increased velocity enhances local heat transfer so that the temperature at hot spots 42 and 44 is substantially reduced to a temperature approaching that of the remainder of the surface of vane 14. In addition to the enhanced convective cooling due to higher velocity air flow in the vicinity of inside surface 26, flow control body 46 also accepts heat from inside surface 26 at contact points 48 and 50 with lands 52. Flow control body 46 is cooled by the passage of cooling air through grooves 54 and thereby is enabled to discharge the heat gained by conduction to the convective process with the moving air.
The effectiveness of flow control body 46 in enhancing cooling depends on a number of controllable factors which can be varied as necessary to achieve the desired cooling effect. For example, it would be clear that the ratio of land 52 to groove 54 together with the depth of groove 54 determines the air velocity flow through groove 54 and consequently the local cooling by convection. It follows, of course, that as the land to groove ratio increases, the amount of heat absorbed by flow control body 46 by conduction increases. When carried to its extreme, with very wide lands 52 and very narrow grooves 54, convective cooling is excessively localized and the less efficient conductive process through the material of flow control body 46 is incapable of adequately compensating. Thus, an upper limit on the land to groove ratio is definable for any particular application by one skilled in the art in view of the teaching of the present invention.
Flow control body 46 of FIGS. 3 and 4 represents a relatively simple and easily manufactured shape which provides an effective improvement in surface cooling. That is, flow control body 46 may be formed from a simple metallic rod of any suitable metal and grooves 54 may be machined as annular grooves.
Referring now to FIG. 5, flow control body 46 is seen in perspective in its position in vane 14. For purposes of illustration, vane 14 is shown affixed to a base 56 which may be, for example, an inner or an outer ring (not shown) of a turbine diaphragm. Although a number of different means may be provided for affixing flow control body 46 in vane 14, in the preferred embodiment, one end 58 of flow control body 46 is welded or otherwise rigidly affixed to vane 14 and the other end 60 is slideably inserted in a hole 62 in base 56. The ability of end 60 to displace lengthwise in hole 62 accommodates differential thermal expansion of flow control body 46 and vane 14.
Referring momentarily to FIG. 3, it will be noted that hot spots 42 and 44 are not disposed opposite to each other, but instead, hot spot 42 is disposed substantially downstream of hot spot 44. Thus, localized cooling provided by flow control body 46 may not be optimally located for relieving both hot spots.
Referring now to FIG. 6, a non-cylindrical flow control body 64 is shown having a generally trapezoidal cross section with lands on a first side 66 contacting inside surface 26 adjacent hot spot 44 and lands of a second side 68 contacting inside surface 26 adjacent hot spot 42. Grooves indicated by dashed lines 70 and 72 in flow control body 64 perform substantially as in the previously described embodiment and will not be further detailed herein. Although the more complex shape of flow control body 64 implies more complex manufacturing processes, such as, for example, casting rather than simpler machining, the improved precision in locating the localized cooling may warrant the extra cost of this approach. In addition, the relatively large area of contact between the land and inside surface 26 may improve conductive heat transfer as compared to the essentially line contact with a cylindrical flow control body as shown in FIGS. 3 and 4.
Referring now to FIG. 7, a flow control body 74 is shown in which a turbulence chamber 76 and 78 is disposed in each side adjacent inside surface 26. This breaks up grooves in each side so that the cooling air passes through a first half groove and into it respective turbulence chamber wherein the increased depth of the turbulence chamber causes mixing and disturbance of the air flow for enhanced cooling after which the air passes through a remaining portion of the groove before exiting through trailing edge channels 34. The embodiment of the invention in FIG. 7 implies that turbulence chambers 76 and 78 be formed as straight vertical grooves in the surfaces of flow control body 74. This is not the only possibility as indicated by an embodiment in FIG. 8. A flow control body 80 has inlet grooves 82 vertically displaced from outlet grooves 84. Inlet and outlet grooves 82 and 84 are joined by a turbulence chamber 86.
Vane 14 is formed by precision investment casting using a pair of cores in a mold to form hollow core 22 with each core extending in from the end and abutting the opposed core. In order to permit mold release, a draft or slight convergent shape is given to the cores. Thus, hollow core 22 converges slightly from its outer ends toward its center. An embodiment of the invention in FIG. 9 accommodates this shape by modifying the diameter of a flow control body 88 into a slightly spindled shape with a maximum diameter land 90 in the center and smaller diameter lands 92 and 94 at the ends. This permits satisfactory contact of the lands with inside surface 26 of vane 14 to improve conductive heat transfer.
In a typical turbine application, the temperature of a vane varies from end to end due to the flow characteristics of the hot gas or steam being directed. Typically, the center of a vane is hotter than its ends.
Referring now to FIG. 10, a flow control body 96 is shown in which the land to groove ratio is varied from the center to the ends to achieve more uniform cooling. Without intending limitation in any way, center grooves 98 surrounding a center land 100 are wider than end grooves 102 with groove widths narrowing progressively from center to end. It will be noted that land widths in flow control body 96 are constant throughout the length and the variation is provided by changing the groove widths. A similar affect may be provided by employing a constant groove width and varying land width. Alternatively, both land and groove widths may be modulated as necessary. Besides these width variations, groove depths may be varied from center to end. That is, center grooves 98 may be made shallower so that the flow velocity is greater in the vicinity of inside surface 26 than at the ends where the grooves are made deeper. Other alternatives would occur to one skilled in the art in view of the teaching herein.
Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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A flow control body in the aft end of a hollow core of a turbine vane provides localized increased velocity cooling air flow in a wide portion which is otherwise difficult to cool. The flow control body includes lands and grooves with the cooling air being constrained to flow through the grooves and provide localized cooling while conductive heat transfer through the lands to the flow control body provides substantial temperature uniformity along the length of the vane. Turbulence chambers may be formed in the flow control body to further control cooling and the shape or other parameters of the flow control body may be modified to accommodate uneven end-to-end heating of the vane.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This nonprovisional patent application claims priority under 35 U.S.C. §119 to U.S. Provisional Application Ser. No. 61/307,204, filed on Feb. 23, 2010.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON COMPACT DISC
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semiautomatic firearms, and particularly to such firearms having a lighter cocking action and less felt recoil.
2. Description of Related Art
Semi-automatic pistols commonly include a slide normally biased in a forward position on the frame, but movable rearwardly of the frame by the recoil produced by a fired cartridge. A recoil spring is coupled to the slide and is compressed as the slide moves rearwardly of the frame. As the slide clears the magazine below and reaches the slide stop, the recoil spring urges the slide back to its original position and loads another cartridge from the magazine into the chamber. Such pistols are initially loaded by inserting a magazine of cartridges into the butt of the pistol, and then manually drawing the slide back against the action of the recoil spring, and then releasing it, to load the first cartridge into the firing chamber and to cock the hammer. After each firing of a cartridge, the pistol thereafter utilizes the recoil produced by the firing of that cartridge to cock the pistol for the next cartridge, and introduce a new cartridge into the chamber.
Manually pulling back the slide to load the first cartridge requires a substantial manual effort, typically in excess of 5-10 pounds of force. Such a large manual force may be difficult to apply for certain persons without the required strength to operate the pistol, particularly by some women or older persons. Moreover, this large manual force to initially load the pistol may limit the strength of the recoil spring that may be used, and thereby the recoil action absorbed by the recoil spring.
Over the years, a number of devices have been developed in connection with semiautomatic firearms to either reduce the cocking effort or felt recoil when firing, including U.S. Pat. No. 4,173,169 to Yates; U.S. Pat. No. 4,201,113 to Seecamp; U.S. Pat. No. 4,344,352 to Yates; and U.S. Pat. No. 5,955,696 to Meller. While these devices may be suited to their specific applications, they do not provide the benefits achievable through use of the present invention.
What is generally needed is a semiautomatic firearm which enables easier or lighter cocking action than is available in current semiautomatic firearms. The lighter cocking action should permit easier loading of a first round from the magazine to the chamber, but should also permit the recoil spring to resume normal function during firing and subsequent loading of rounds from the magazine. Finally, the improved mechanisms described herein should be implemented in a manner that avoids or minimizes additional weight or volume to the resulting firearm.
SUMMARY OF THE INVENTION
A semiautomatic firearm with reduced cocking action and reduced recoil is provided, comprising a firing chamber, a barrel, a frame, a slide movable with respect to the barrel and the frame between battery and full recoil positions, means for sequentially ejecting a spent cartridge and loading a fresh cartridge during each recoil cycle, and a firing mechanism for firing the cartridge when the slide is in battery, wherein the improvement comprises an assembly for enabling only a single lighter spring to cock the pistol and/or load a first cartridge.
In a preferred embodiment, the assembly comprises a spring tube having a rear end and a front end, and including an outer surface and a pair of diametrically opposed longitudinal slots extending from the front end to the rear end, and wherein the spring tube is slidably disposed within an opening in the slide. An inner spring resides within the spring tube, wherein the inner spring includes a first spring constant. An outer spring resides around the outer surface of the spring tube, wherein the outer spring includes a second spring constant and an annular cap connected to the front end of the outer spring.
Preferably, a locking device is disposed within the front end of the inner spring, and having opposing tabs slidably engaged within the slots of the spring tube and with the opening of the slide, and wherein the opposing tabs are biased against the front end of the slots by the annular cap of the outer spring.
A spring stop is operatively connected to the rear end of the spring tube and engaged with the barrel, wherein the spring stop includes a rod residing coaxially within the inner spring.
An anti-rotation spring is operatively attached between the spring tube and the spring stop, wherein the anti-rotation spring is adapted to permit partial and biased rotation of the spring tube and the locking device relative to the spring stop between a first rotational position and a second rotational position.
The opening in the slide includes opposing recesses adapted to permit slidable passage of the opposing tabs through the opposing recesses, and to allow compression of only the outer spring, when the locking device and the spring tube are in the second rotational position for loading a first cartridge.
Also, the opposing tabs are engaged by the slide, and both the inner spring and the outer spring are allowed to compress, when the locking device and the spring tube are in the first rotational position for firing the first cartridge and subsequent cartridges.
Preferably, the spring stop includes a detent engaged with a first end of the anti-rotation spring, and wherein the spring stop includes a clamp engaged with the detent and with the spring tube.
In a preferred embodiment, the longitudinal slots are closed at the front end of the spring tube and open at the rear end of the spring tube.
The firearm further includes means for resetting the locking device from the second rotational position back to the first rotational position.
Preferably, each of the opposing recesses of the opening in the slide include a ramp slidably engageable with one of the opposing tabs of the locking device; and a locking surface adjacent to the ramp adapted to receive and lock the opposing tab in the first rotational position.
Also more preferably, the slide includes an unlocking device adapted to move the opposing tabs of the locking device from the locked first rotational position to the second rotational position.
More preferably, the unlocking device includes a grip member slidably disposed along the slide; a connecting member extending from the grip member, wherein the connecting member includes a plunger ramp; and a plunger slidably disposed within a plunger slot on the slide, wherein the plunger is operatively engaged between the plunger ramp and one of the opposing tabs of the locking device.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements.
FIG. 1 shows an exploded perspective view of selected components in accordance with one embodiment of the present invention.
FIG. 2 shows an assembled view of the embodiment of FIG. 1 .
FIG. 3 shows an assembly view of the invention in combination with the barrel and slide of a semiautomatic firearm with the assembly in a pre-cocked configuration.
FIG. 4 shows an assembly view of the invention during a cocking action and loading of a first cartridge, wherein only the outer spring is compressed, because the locking device and spring tube are in a first rotational position.
FIG. 5 shows an assembly view of the invention during the firing of subsequent cartridges, wherein both the outer spring and the inner spring are compressed, because the locking device and the spring tube are in a second rotational position.
FIGS. 5A-5C show detailed views of invention at different stages of the assembly.
FIGS. 6A and 6B show partial sectional side views of the front of the firearm depicting the operation of the locking device and unlocking device relative to the slide.
FIG. 7 shows a perspective view of one embodiment of a modified front portion of the slide used in connection with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Before the subject invention is further described, it is to be understood that the invention is not limited to the particular embodiments of the invention described below, as variations of the particular embodiments may be made and still fall within the scope of the appended claims. It is also to be understood that the terminology employed is for the purpose of describing particular embodiments, and is not intended to be limiting. Instead, the scope of the present invention will be established by the appended claims.
In this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs.
Turning now to FIGS. 1 and 2 , the invention relates to improvements to a semiautomatic firearm 1 to provide reduced cocking effort and easier loading of a first cartridge (or “round”), as well as reduced felt recoil. All semiautomatic pistols 1 include a firing chamber 2 , a barrel 3 , a frame, a slide 5 movable with respect to the barrel 3 and the frame between battery and full recoil positions, means for sequentially ejecting a spent cartridge and loading a fresh cartridge during each recoil cycle, and a firing mechanism for firing the cartridge when the slide 5 is in battery. FIGS. 3-5 are shown with a partially assembled view of the firearm to illustrate the internal components described herein. It should be appreciated that the grip and frame of the firearm should remain essentially unchanged from a conventional semiautomatic pistol, except for differences specific to designs from various manufacturers.
With reference to the exploded view of FIG. 1 , in a preferred embodiment, the improved firearm 1 comprises a spring tube 6 having a rear end 7 and a front end 8 , and including an outer surface and a pair of diametrically opposed longitudinal slots 9 extending from the front end 8 to the rear end 7 , and wherein the spring tube 6 is slidably disposed within an opening 10 in the slide 5 (best shown in FIGS. 4 and 5 ).
An inner spring 11 resides within the spring tube 6 , wherein the inner spring 11 includes a first spring constant. In a more preferred embodiment, the inner spring 11 is the main recoil spring, although such arrangement is not necessarily required by the present invention.
An outer spring 12 resides around the outer surface of the spring tube 6 , wherein the outer spring 12 includes a second spring constant. As mentioned above, the inner spring 11 may often be the main recoil spring. If that is the case, then the second spring constant of the outer spring 12 would be less than the first spring constant of the inner spring 11 . In other words, the outer spring 12 would be much lighter, or easier to compress, than the inner spring 11 . The outer spring 12 includes an annular cap 13 connected to the front end of the outer spring 12 .
A locking device 14 is disposed within the front end of the inner spring 11 (best shown in FIGS. 2 and 4 ), and includes opposing tabs 15 slidably engaged within the slots 9 of the spring tube 6 when fully assembled. The opposing tabs 15 are biased against the front end of the slots 9 by inner spring 11 , because the inner spring 11 should be slightly compressed during assembly.
A spring stop assembly 16 is operatively connected to the rear end of the spring tube 6 and engaged with the barrel 3 , wherein the spring stop assembly 16 includes a base member 21 having a curved portion 22 to engage the barrel 3 , and a rod 17 residing coaxially within the inner spring 11 . The spring stop assembly 16 is shown best in FIGS. 5A-5C , which figures illustrate the sequential addition of other components for clarity, as will be further explained below. The base member 21 further includes an annular concave surface 23 that provides a seat for the inner spring 11 and ensures concentricity between the inner spring 11 and rod 17 . The base member 21 also includes an anti-rotation spring mounting surface 24 that is coaxial with rod 17 .
With further reference to FIG. 5A , an anti-rotation spring 18 roughly in the shape of a partial or open band is operatively attached around the surface 24 . The anti-rotation spring 18 includes a first flange 25 and a second flange 26 . When the anti-rotation spring 18 is installed, the second flange 26 rests partially on a boss 27 protruding from the face of the base member 21 . Thus, an angular gap A is present when the anti-rotation spring 18 is uncompressed. As will be appreciated, the inside diameter of the anti-rotation spring 18 should be slightly larger than the diameter of the surface 24 so that full compression of the spring 18 between the first and second flanges 25 , 26 may be accomplished unimpeded.
With reference to FIG. 5B , the inner spring 11 is shown inserted within the spring tube 6 , and the spring tube 6 and inner spring 11 are mounted on the rod 17 . As described above, the locking device 14 is also positioned on the opposite end of the inner spring 11 and is biased against the ends of slots 9 , as shown in FIGS. 2 and 4 . To secure the components for assembly, the spring tube 6 includes a circumferential flange 28 that rests against the face of base member 21 . A U-shaped clamp 20 having a C-shaped cross section is mounted onto the base member 21 to firmly retain the spring tube 6 to the base member 21 . Although the clamp 20 may be secured in various ways, the means in FIG. 5B illustrates a notch in the clamp 20 that snaps onto the boss 27 . In the preferred embodiment, the spring tube 6 further includes a cutout portion 30 at the rear end of one of the slots 9 . The cutout portion 30 should be sized such that the bottom edge 31 of the slot 9 fits snugly under the boss 27 , and such that the upper edge 32 of the cutout portion 30 rests on the first flange 25 of the anti-rotation spring 18 . When assembled, the anti-rotation spring 18 should be slightly in compression to avoid rattling and ensure a secure fit. From this arrangement, it can be understood that the anti-rotation spring 18 is compressed when the locking device 14 and the spring tube 6 are rotated relative to the base member 21 through angle A between a first rotational position (shown in FIGS. 5B and 5C ) and a second rotational position. The maximum rotation is achieved when the first and second flanges 25 , 26 are contacting each other.
With reference to FIG. 5C , the outer spring 12 is shown added to the assembly, such that the rear end of the outer spring 12 rests against the clamp 20 . The front end of the outer spring 12 and the annular cap 13 are slightly biased against the opposing tabs 15 of the locking device 14 , as shown in FIG. 2 .
Referring now to FIGS. 3-5 , and FIGS. 6A , 6 B, and 7 , in a preferred embodiment, the opening 10 in the slide 5 includes opposing recesses 19 adapted to permit slidable passage of the opposing tabs 15 through the opposing recesses 19 , and to permit axial compression of only the outer spring 12 , after the locking device 14 and the spring tube 6 are rotated from the first rotational position. Each of the opposing recesses 19 of the opening 10 in the slide 5 include a ramp 35 slidably engageable with one of the opposing tabs 15 of the locking device 14 . Each recess 19 also includes a locking surface 36 adjacent to the ramp 35 adapted to receive and lock the opposing tab 15 in the second rotational position. More preferably, the locking surface 36 has an adjacent concave surface 37 , such that when the opposing tab 15 is seated on the locking surface 36 , inadvertent dislodgement of the opposing tab 15 from the first rotational position is avoided. As can be appreciated, the internal features of the opposing recesses 19 just described for the left-most recess 19 of FIG. 7 are inverted for the right-most recess 19 . Specifically, when the opposing tabs 15 are urged against the ramps 35 , the locking device 14 and the spring tube 6 are caused to rotate clockwise (from the view in FIG. 7 ). Thus, when the locking device 14 is fully seated in the first rotational position on locking surfaces 36 , pulling back the slide 5 will cause both inner spring 11 and outer spring 12 to be compressed. Such configuration represents the arrangement desired for normal firing and cycling of the firearm, because the inner spring 11 (typically the main recoil spring) is employed.
However, when the user desires to manually load a new cartridge into the firearm, the locking device 14 needs to be disengaged from the slide 5 so that only the outer spring 12 is employed. To accomplish this function, the slide 5 includes an unlocking device 40 adapted to move the opposing tabs 15 of the locking device 14 from the locked first rotational position to a second rotational position.
In a preferred embodiment, and with reference to FIGS. 3-5 , 6 A, 6 B, and 7 , the unlocking device 40 includes a grip member slidably disposed along the slide 5 , such as on a slidable rail. The grip member 41 moves relative to the slide 5 through a short distance D when pulled back, until it reaches a stop member 42 on the slide 5 . A connecting member 43 extends from the grip member 41 toward the front of the slide 5 , wherein the connecting member 43 includes a plunger ramp 44 with an inclined surface positioned above the locking device 14 . A plunger rod 45 is slidably disposed within a plunger slot 46 on the slide 5 , such that the upper end of the plunger rod 45 is in slidable contact with the plunger ramp 44 , and such that the lower end of the plunger rod 45 is immediately above the opposing tab 15 of the locking device 14 . The plunger rod 45 and plunger slot 46 may include means to spring-load the plunger rod 45 or otherwise limit its slidable range within the plunger slot 46 so as not to interfere with the return of the opposing tabs 15 when the slide 5 is closed.
Thus, starting from the position shown in FIG. 6A , when the grip member 41 is pulled back, the plunger ramp 44 causes the plunger rod 45 to move downward within the plunger slot 46 in proportion to the distance D against the resistance of the opposing tab 15 of the locking device 14 . At the maximum position of the grip member 41 , the plunger rod 45 has rotated the opposing tabs 15 away from their respective locking surfaces 36 . Such action takes place against the resistance of the anti-rotation spring 18 described above. Further pulling of the grip member 41 will cause the entire slide 5 to move backward, while the opposing tabs 15 pass through their respective recesses 19 . After the opposing tabs pass through the recesses 19 , the locking device 14 and spring tube 6 resume their normal horizontal position by the expansion of the anti-rotation spring 18 . Concurrently, the slide 5 can be fully retracted against the force of the outer spring 12 alone until the trigger mechanism is cocked and the slide 5 reaches it maximum travel.
After the slide 5 is fully retracted against the outer spring 12 only, it can be released to strip a cartridge from the magazine and place the cartridge into the firing chamber 2 . Return of the slide 5 toward its closed position then causes the opposing tabs 15 of the locking device 14 to contact the ramps 35 within the recesses 19 . Prior to the slide 5 reaching its full forward position, the opposing tabs 15 slide along the ramps 35 against the force of the anti-rotation spring 18 until they snap back onto the locking surfaces 36 . Simultaneously with this action, the plunger ramp 44 and plunger rod 45 are returned to their original positions shown in FIG. 6B .
Now that the firearm has been manually loaded, it can be fired in the normal manner. When the cartridge is fired, the slide 5 now moves backward with the opposing tabs 15 of the locking device 14 locked in the first rotational position. Therefore, cycling of the action and subsequent stripping of the cartridges from the magazine occur against the resistance of both the inner spring 11 and the outer spring 12 . Advantageously, this condition also helps to reduce felt recoil during firing.
The unlocking device assembly 40 , and particularly the connecting member 43 , plunger ramp 44 , and plunger 45 are preferably enclosed within a cover on the slide 5 so that such components are fully protected. Also, with respect to the choice of springs and spring constants for the inner spring 1 and the outer spring 12 , persons of ordinary skill in the art of firearms design will appreciate that specific spring selection will vary, taking into consideration the dynamics of the particular firearm, ammunition type, and other factors.
Notably, the spring constant for the outer spring 12 only needs to be sufficient to prevent inadvertent or undesired movement of the slide 5 relative to the frame during handling of the firearm Likewise, the spring constant of the outer spring 12 should not be too strong as to adversely affect the dynamics of the recoil and loading action of the firearm.
It should be emphasized that the invention is not limited to pistols, but may also be applied with suitable modification to rifles, shotguns, and similar semiautomatic firearms where it may be desirable to reduce the effort required to cock the firearm and/or load a first cartridge. The invention can also be implemented in a manner that does not appreciably increase the weight or size of the firearm.
All references cited in this specification are herein incorporated by reference as though each reference was specifically and individually indicated to be incorporated by reference. The citation of any reference is for its disclosure prior to the filing date and should not be construed as an admission that the present invention is not entitled to antedate such reference by virtue of prior invention.
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention set forth in the appended claims. The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
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An improved semiautomatic firearm is provided comprising as assembly which reduces the effort of cocking the firearm or loading a first cartridge. A spring tube contains an inner recoil spring which is employed only during cycling of the firearm when firing. For initial cocking purposes, the inner recoil spring is bypassed in favor of a lighter outer spring which is selectively engaged by the user. When the inner recoil spring is engaged, both inner and outer springs are employed without adversely affecting the recoil dynamics of the firearm.
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PROVISIONAL APPLICATIONS
[0001] This application claims the benefit of Provisional application 60/211,645 filed Jun. 14, 2000.
[0002] RELATED APPLICATIONS
[0003] Commonly-assigned, copending U.S. patent application, No. 09/439,980, entitled “Nonintrusive Update Of Files”, filed Nov. 12, 1999.
FIELD OF THE INVENTION
[0004] This invention relates to data network systems, and more particularly to file system for distributing content in a data network and methods relating to the same.
BACKGROUND OF THE INVENTION
[0005] Data network usage is growing rapidly due, in part, to the ease of distributing content over the Internet and the World Wide Web (the “Web”), which has been simplified by the emergence of the Hypertext Markup Language (“HTML”) and the Hypertext Transfer Protocol (“HTTP”). Increased data network usage is also due to recent advances in networking technology, which provide ever-increasing storage capacity for content providers, and ever-increasing connection bandwidth for end users.
[0006] The Internet is an internetwork of networks, routers, backbones, and other switches and connections that separate a source of content from a user. Providing content from a single source to a single user becomes complex for a large, distributed network such as the Internet. Responding to requests from numerous users, who may be widely geographically distributed, and who may present widely varying traffic demands over time, becomes very complex. Inadequate management of network resources may result in the sluggish performance that is familiar to Internet users as slow page loading or outright failure of a request to a server.
[0007] One approach to this difficulty is to provide “mirror sites,” which are content servers that supply identical content on one or more sites associated with an original content provider. However, mirror sites do not function well in highly dynamic environments, where frequent content changes require frequent mirror updates. Mirror sites are particularly deficient in environments where there are small changes to large files, since there is no efficient mechanism for transmitting incremental file changes to mirrors.
[0008] Accordingly, a system and/or method is still needed for efficiently distributing content in a data network. Such a system should be scalable to the Internet and transparent to users and content providers.
SUMMARY OF THE INVENTION
[0009] According to one aspect of the invention, a file system for distributing content in a data network, comprises a file replication and transfer system and a replicated file receiver system. The file replication and transfer system includes an interface file system which looks for changes made to contents of a file created and stored in an associated work file system. A file system monitor is communicatively associated with the interface filing system monitors events occurring with the interface file system and causes copies of the new files to be transferred over the data network to the replicated file receiver system.
[0010] According to another aspect of the invention, the interface file system looks for changes made to the contents of files already stored in the work file system and creates an update file in a mirror file system if a change to the contents of a file stored in the work file system is observed by the interface file system.
[0011] According to a further aspect of the invention, a collector file system communicatively associated with the mirror file system can be provided for temporarily storing a copy of the update file.
[0012] According to a further aspect of the invention, the replicated file receiver system includes a file construction system for constructing a new version of the file from a copy of the file and the update file.
[0013] According to a further aspect of the invention, the replicated file receiver system further includes a receiver collector file system for storing the new version of the file.
[0014] According to a further aspect of the invention, the replicated file receiver system further includes a receiver interface file system for enabling work to be conducted with the copy of the file if an open request for the copy of the file has been made prior to the construction of the new version of the file, and for enabling work to be conducted with the new version of the file if an open request for the copy of the file has been made after the notification that the new version of the file has been constructed.
[0015] According to a further aspect of the invention , a method for distributing content in a data network comprises creating an update file which records changes made to contents of a file stored in a work file system; generating a notification that the at least one change has been made to the contents of the file stored in the work file system, the notification indicating that the update file reflects all the changes of a version of the file; and distributing the update file over the data network to a receiver work file system.
[0016] According to a further aspect of the invention, a method for distributing content in a data network, comprises looking for changes made to contents of a file stored in a work file system; creating an update file which records only changes made to the contents of the file stored in the work file system; and distributing the update file over the data network to a receiver work file system; wherein the looking and creating steps are performed in a kernel mode.
[0017] According to a further aspect of the invention, a method for distributing content in a data network, comprises creating and storing a file in a work file system; generating a notification that the file has been created and stored in the work file system; and distributing a copy of the file over the data network to a receiver work file system.
[0018] According to a further aspect of the invention, a method for distributing content in a data network, comprises looking for files created and stored in a work file system; and distributing copies of the files over the data network to a receiver work file system operating at a second location; wherein the looking step is performed in a kernel mode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The advantages, nature, and various additional features of the invention will appear more fully upon consideration of the illustrative embodiments now to be described in detail in connection with accompanying drawings wherein:
[0020] [0020]FIG. 1 is a diagram of a file system for distributing content on a data network according to an exemplary embodiment of the present invention;
[0021] [0021]FIG. 2 is a block diagram of the file replication and transfer system according to an exemplary embodiment of the present invention;
[0022] [0022]FIG. 3 is a block diagram of the file system monitor application according to an exemplary embodiment of the present invention;
[0023] [0023]FIG. 4A is a diagram of an update file having a file map appended as a list to an end thereof;
[0024] [0024]FIG. 4B is an enlarged diagram of three file maps;
[0025] [0025]FIG. 4C is an enlarged diagram of a file map created by combining the file maps illustrated in FIG. 4B;
[0026] [0026]FIG. 5 is a timing diagram that illustrates how the file replication and transfer system processes write, read and delete requests generated from one or more application processes;
[0027] [0027]FIG. 6 is a timing diagram that illustrates how the file update replication and transfer system of the present invention processes close requests generated from one or more application processes and prepares the update file for transfer;
[0028] [0028]FIG. 7 is a block diagram of the replicated file receiver system according to an exemplary embodiment of the present invention; and
[0029] [0029]FIGS. 8A and 8B illustrate how the replicated file receiver system on each of the servers at the mirror sites works with both the new and old versions of a file.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The file system of the present invention, as described with reference to following illustrative embodiments, is especially applicable to data networks such as the Internet. It should be understood, however, that the file system described herein may be suitably adapted to any other data network used for distributing content, including wide area networks, metropolitan area networks, virtual private networks, and the like. The file system of the present invention is particularly applicable to those environments requiring distribution of large amounts of data that may be changed from time to time. Furthermore, the file system of the present invention can be adapted for use with virtually any conventional operating system including but not limited to Microsoft Windows 95, Microsoft Windows NT, or Unix and its variants.
[0031] As used herein, the term content can be any media that may be stored in a digital form, including text, data files, program files, application documents such as word processing or spread sheet documents, still or moving graphical images, sound files, applications, applets, HTML documents, DHTML documents, XML documents, forms, or any combination of these. Content may also be real-time media such as streaming media.
[0032] [0032]FIG. 1 diagrammatically illustrates a file system for distributing content on a data network according to an exemplary embodiment of the present invention. The file system comprises a file replication and transfer system 10 on a file storing and serving device 20 at a master site 30 and a plurality of replicated file receiver systems 40 on respective file storing and serving devices 50 at remotely located mirror sites 60 . The file storing and serving devices 20 , 50 typically comprise conventional file servers or any other suitable device for storing and serving files. The file storing and serving devices 20 , 50 at the master and mirror sites 30 , 60 are communicatively connected by a network, which may be any private or public network, or any mix thereof, suitable for carrying data. The mirror sites 60 may be geographically distributed, for example, on regional backbones of the Internet. The file storing and serving devices 50 at each mirror site 60 may include a copy of the files stored on the file storing and serving device 20 at the master site 30 . The file storing and serving device 50 at the mirror sites 60 may also be communicatively connected with one another so that file changes can be distributed among the file storing and serving devices 50 at the mirror sites 60 . One of the primary goals of the file system of the present invention is to look for changes made to existing files on the file storing and serving device 20 at the master site 30 and new files created on the file storing and serving device 20 at the master site 30 , replicate these files changes and new files and transfer the replicated file changes and new files to one or more of the file storing and serving devices 50 at the mirror sites 60 as will be described in greater detail below.
[0033] [0033]FIG. 2 is a block diagram of the file replication and transfer system 10 according to an exemplary embodiment of the present invention. The file replication and transfer system 10 comprises: an interface file system 101 ; a mirror file system 102 ; a collector file system 103 ; and a file system monitor 104 . The interface file system 101 is mounted or stacked on top of the file storing and serving device's 20 work file system 105 and responds to calls from, and returns data to, an input/output (I/O) library 106 which converts user mode requests or commands from an application process 124 into kernel mode system calls that invoke certain events from the interface file system 101 .
[0034] The work file system 105 , on top of which the interface file system 101 is mounted, may include a work directory 107 , a disk driver 108 and a disk drive 109 . The mirror file system 102 may include a mirror directory 110 , a disk driver 111 and a disk drive 112 . The collector file system 103 may include a collector directory 113 a disk driver 114 and a disk drive 115 . The file system monitor 104 may include a file system monitor application 116 , a spool directory 117 , a disk driver 118 , a disk drive 119 , and an input/output (I/O) library 120 . The operations and interactions which take place between the directories 107 , 110 , 113 , 117 and their associated disk drivers 108 , 111 , 114 , 118 and disk drives 109 , 112 , 115 , 119 are well known in the art and, therefore, need not be discussed further herein. The file system monitor's input/output (I/O) library 120 converts user mode file system monitor application requests or commands into kernel mode system calls that invoke certain events from the spool directory 117 .
[0035] It should be noted that the disk drives 109 , 112 , 115 , 119 utilized in the work, mirror, and collector file systems 105 , 102 , 103 and the file system monitor 104 are exemplary and may be replaced by other physical or virtual memory devices in other embodiments of the present invention. For example the disk drives 109 , 112 , 115 , 119 may be partitions or directories of a single disk drive. However, persons of ordinary skill in the art will recognize that separate physical memory devices are preferred as they usually improve efficiency where access to the disk drives 109 , 112 , 115 , 119 is made independently or simultaneously, or if the mirror and collector disk drives 112 , 115 actually share the same physical disk device.
[0036] [0036]FIG. 3 is a block diagram of the file system monitor application 116 according to an exemplary embodiment of the present invention. The file system monitor application, which is a key component of the file system monitor 104 , 116 may include a compression utility 121 , an output queue 122 and a network transfer utility 123 . The file system monitor application 116 and the interface file system 101 communicate with each other through any suitable protocol. This permits the file system monitor application 116 , which runs in the user mode, to monitor asynchronous events occurring with the interface file system 101 in the kernel mode. With the knowledge of events occurring with the interface system 101 , the file system monitor 104 causes the collector, mirror, and work file systems in the kernel mode to transfer replicated file updates and/or replicated newly created files (generated in the work file system) to the file system monitor's the spool directory 117 , where they will then be transferred at the appropriate time to the replicated file receiver systems on the servers at the mirror sites.
[0037] Referring collectively now to FIGS. 2 and 3, the general operation of the file replication and transfer system 10 of the present will now be described. In the user mode, the application process 124 generates a request or command for a file. The application process 124 may be any computer application that might operate on a file. The application process 124 may dictate a specific user mode request for a file, by which a user or process may read data from, or write data to a file. The I/O library 106 on the user level converts the file request into a system call suitable for a kernel mode. System calls may include, for example, open calls, close calls, read calls, write calls, create file calls, delete file calls, rename file calls, change attribute file calls, truncate file calls, and the like. The file storing and serving device's 20 operating system kernel (not illustrated), in response to the system call generated in the kernel mode by the I/O library 106 , sends the call to the interface file system 101 . The interface file system 101 passes the system call to the work file system 105 for conventional processing without any interruption. The interface file system 101 will also replicate the system call, if it relates to a file change or deletion, and send the replicated call to the mirror file system 102 . In response to the system call, the mirror file system 102 will create and store a record representative of the file change (update file). The update file replicates the changes made to the corresponding file stored in the work file system.
[0038] At an appropriate time as requested by the file system monitor 104 , update files may be copied from the mirror file system 102 to the collector file system 103 . When appropriate, the file system monitor 104 will then request the update file to be copied from the collector file system 103 to its spool directory 117 . In the case of a new file written to the work file system 105 , when appropriate, the file system monitor 104 will request the new file to be copied directly from the work file system 105 to its spool directory 117 . As the update file or replicated new file is copied to the spool directory, the compression utility 121 of the file system monitor application 116 may be employed to compress the file if necessary. For example, if the file is already well compressed, such as in the case of a MPEG or JPEG encoded file, compression via the compression utility 121 would not ordinarily be required. The file system monitor application 116 may also perform additional functions, such as encryption of the update files and new files, and may include any other control, authentication, or error correction information along with the update file data for transmission therewith, or in a header appended thereto. For example, authentication may be performed using MD4, MD5, double MD5 (e.g., E=MD5(key1,MD5(key2, pass)), or any other one-way hash function or other suitable authentication scheme.
[0039] A further function of the file system monitor 104 includes using the information obtained from the knowledge of the events occurring with the interface file system 101 , which may contain details concerning control information, file size, and offsets, to create a file map of the update file. The file map and possible other subsequent file maps corresponding to changes made to the update file are generated by the network transfer utility 123 and appended as a list to the end of the update file as shown in FIG. 4A, when the network transfer utility 123 transfers the file from the spool directory 117 to the replicated file receiver systems 40 on the servers 50 at the mirror sites 60 . A pointer, which comprises some type of data, is used to identify where the list begins, i.e., identifies the list offset. The file map enables the replicated file receiver systems 40 on the servers 50 at the mirror sites 60 to construct a new version of the corresponding existing file stored thereon using the data from the update file and the data from the existing file. A truncate file call may be presented in the map as a separate field.
[0040] The file map also enables the file system monitor 104 to optimize the update file prior to its transfer to the mirror sites. For example, if the file system generates three maps for a particular update file (indicative of two subsequent changes made to the update file), as illustrated in FIG. 4B, data in two or more of these maps may be combined into a single map as illustrated in FIG. 4C, if the data in the maps overlap. Thus, only the single map need be appended to the update file when it is transferred.
[0041] Referring again to FIGS. 2 and 3, as the replicated update file (or replicated new file) is copied to the spool directory 117 of the file system monitor 104 , file information is transmitted to the queue 122 in the file system monitor application 116 . The network transfer utility 123 of the file system monitor application uses queuing information obtained from the queue 122 to transfer the update files and/or replicated new files stored in the spool directory over the network to the replicated file receiver systems 40 running on the servers 50 at the mirror sites 60 .
[0042] The file replication and transfer system 10 of the present invention uses the transparency of the kernel mode to the user mode in a manner that permits it to transparently track changes made to files stored in the server 20 at the master site 30 or track new files created on the server 20 at the master site 30 . By tracking changes in the kernel mode, user mode application processes may make changes to files stored in the server hardware level, and these changes may be tracked without any explicit action in the user mode. Tracking changes in the kernel mode in accordance with the present invention, also permits incremental changes to be sent to the replicated file receiver systems 40 operating on the servers 50 at the mirror sites 60 without transmitting and replacing potentially large files.
[0043] [0043]FIG. 5 illustrates how the file replication and transfer system 10 of the present invention may process write, read and delete requests generated from one or more application processes. At time T 1 , the application process 124 submits a write request to write to a file stored in the work file system 105 , and the I/O library 106 (FIG. 2) outputs an appropriate call such as write (fd, offset, *data, data_size) to the kernel 125 . The write call may include a file descriptorfd (generated in a previously processed open call open(fname)) that provides a method for identifying which file stored in the work file system 105 is to be changed. The write call will also include information about what is going to be written to the file, i.e., offset, *data, and data_size. At time T 2 , the kernel 125 sends the write call to the interface file system 101 . At time T 3 , the interface file system 101 passes the write call to the work file system 105 , which responds to the call by writing the data_size bytes of data pointed to by the pointer, *data, to the file stored therein identified by fd, at a location within that file defined by the offset.
[0044] At time T 3 , the interface file system 101 also replicates the write call write (fd, offset, *data, data_size) and sends it to the mirror file system 102 . In response thereto, the mirror file system 102 creates and stores an update file that replicates only the new data just written to the file fd in the work file system 105 . The update file has a size equal to the file fd stored in the work file system 105 , i.e., data_size plus the offset, but includes only the new data submitted in the write call. Since the update file includes only data changes resulting from the write call, it is highly compressible. Any subsequent changes written to the file fd in the work file system 105 will be recorded in the update file in the mirror file system 102 , while subsequent changes to different files in the work file system 105 will respectively result in the creation of additional update files in the mirror file system 102 .
[0045] At time T 4 , the interface file system 101 sends an event to the file system monitor 104 which indicates that the mirror file system 102 has created and stored an update file which represents the new data written to file fd in the work file system 105 . This event includes parameters for generating a file map. As discussed earlier, this and any other maps corresponding to changes made in the update file will be appended as a list to the end of the update file.
[0046] The interface file system 101 is transparent for read system calls. For example, at time T 5 , the application process 124 may submit a read request to read the file fd stored in the work file system 105 . In response thereto, the I/O library 106 outputs an appropriate call such as read(fd) to the kernel 125 . At time T 6 , the kernel sends the read call to the interface file system 101 . At time T 7 , the interface file system 101 simply passes the read call to the work file system 105 where it is conventionally processed. Because read system calls require no changes to the file fd, no action is taken by the interface file system 101 , therefore no event is sent to the file system monitor 104 .
[0047] At time T 8 , the application process may then submit a delete request to delete the file fd stored in the work file system 105 . The I/O library 106 , therefore, outputs an appropriate call such as delete (fd) to the kernel. At time T 9 , the kernel sends the delete call to the interface file system 101 . At time T 10 , the interface file system 101 passes the delete call to the work file system 105 , which results in deletion of the file fd. The interface file system 101 also replicates the delete call and sends it to the mirror file system 102 , which results in deletion of the corresponding update file from the mirror file system 102 . (The interface file system 101 takes no action if no corresponding update file exists in the mirror file system 102 .) At time T 11 , the interface file system 101 sends an event to the file system monitor 104 which indicates that the mirror file system 102 has deleted the update file. When this happens, file map information corresponding to that file is deleted from the file system monitor 104 . Note that the system actions from time T 8 to time T 11 also take place when a file is renamed, truncated or its attributes are changed.
[0048] [0048]FIG. 6 illustrates how the file update replication and transfer system of the present invention may process close requests generated from one or more application processes and may prepare the update file for transfer. For the sake of clarity, only critical interactions are described as one of ordinary skill in the art will recognize that other less critical interactions may be taking place, such interactions being well known in the art. At some moment in time, it will become desirable to transfer an update file stored in the mirror file system to the replicated file receiver systems 40 of the servers 50 at the mirror sites 60 (FIG. 1). If the update file is transferred at this time, it may still be open and receiving writing changes from one or more application processes and, therefore, may be inconsistent. Thus, in order to ensure the consistency of the data in the update file, i.e., the update file reflects all the changes of some version of the a file fd, when possible (just as the version of the file fd comes into existence), the kernel 125 sends a clean-up event or any other equivalent notice to the update file system 101 . This will typically happen when close calls close(fd) are received by the kernel via the I/O library 106 (FIG. 2) from each open application process 126 , 127 , 128 such as at times T 1 , T 2 , and T 3 . When the last application process 128 has closed the file in the work file system 105 , such as at time T 4 the kernel 125 will then send the aforementioned cleanup event to the interface file system 101 . The cleanup event enables the interface file system 101 to know that the file in the work file system 105 is finally closed. At time T 5 , the interface file system 101 passes the cleanup event to the work file system 105 for processing. At time T 6 , the interface file system sends a request to the kernel 125 to close the update file in the mirror file system 102 . At time T 7 , the kernel sends a cleanup event to the mirror file system 102 , which closes the update file, resulting in a version thereof (with consistent data) in the mirror file system 102 . At time T 8 , the interface file system 101 sends an event to the file system monitor 104 , which indicates that some version of the update file is now stored in the mirror file system 102 .
[0049] At some time T 9 , the transfer process commences under the control of the file system monitor 104 , which sends a special request to the interface file system 101 . In response thereto, the interface file system 101 may copy the update file in the mirror file system 102 to the collector file system 103 , or it may postpone the copy if the file in working file system 105 and the update file in the mirror file system 102 are open again by some application. At some time T 10 the interface file system 101 copies the update file in the mirror file system 102 to the collector file system 103 . At some time T 11 the interface file system sends an event to the file system monitor 104 , which indicates that some version of the update file is now stored in the collector file system 103 . The copy command may alternatively result in only a renaming of the update file when the file systems reside on the same partitions of a disk drive and no physical relocation is required to reflect the file's reassignment to the new file system.
[0050] Then at some other moment in time T 12 , the file system monitor 104 may send a second copy command to the kernel 125 . This copy command causes the update file to be copied from the collector file system 103 to the spool directory 117 of the file system monitor 104 . As the update file is copied to the spool directory 117 , it may be compressed by the compression utility 121 of the file system monitor application 116 if deemed necessary. Once in the spool directory 117 , the update file can be transferred to the replicated file receiver systems 40 on the servers 50 at the mirror sites 60 .
[0051] [0051]FIG. 7 is a block diagram of the replicated file receiver system 40 , on each of the servers at the mirror sites, according to an exemplary embodiment of the present invention. The replicated file receiver system 40 typically comprises: a receiver interface file system 201 ; a receiver collector file system 202 ; and a file construction system 203 . The receiver interface file system 201 is mounted or stacked on top of the mirror server's 50 receiver work file system 204 and responds to calls from, and returns data to, an input/output (I/O) library 215 which converts user mode requests or commands from an application process 217 into kernel mode system calls that invoke certain events from the receiver interface file system 201 .
[0052] The receiver work file system 204 may include a receiver work directory 205 , a disk driver 206 and a disk drive 207 . The receiver collector file system 202 may include a receiver collector directory 208 a disk driver 209 and a disk drive 210 . The file construction system 203 may include a file construction application 211 , a receiver spool directory 212 , a disk driver 213 , a disk drive 214 , and an input/output (I/O) library 216 . The operations and interactions which take place between the directories 205 , 208 , 212 and their associated disk drivers 206 , 209 , 213 and disk drives 207 , 210 , 214 are well known in the art and, therefore, need not be discussed further herein. The input/output (I/O) library 216 of the file construction system 203 converts user mode file construction system application requests or commands into kernel mode system calls that invoke certain events from the receiver spool directory 212 .
[0053] It should be noted that the disk drives 207 , 210 , 214 utilized in the receiver work and collector file systems 204 , 202 and the file construction system 203 are exemplary and may be replaced by other physical or virtual memory devices in other embodiments of the present invention. For example the disk drives 207 , 210 , 214 may be partitions of a single disk drive. However, persons of ordinary skill in the art will recognize that separate physical memory devices are preferred as they usually improve efficiency where access to the disk drives 207 , 210 , 214 is made independently or simultaneously.
[0054] The file construction system 203 receives data pertaining to update files or new files from the network (transferred from the file replication and transfer system 10 on the master site server 20 ). The file construction application 211 decodes this data to create a copy of the update file in the receiver spool directory 212 . The file construction application 211 can be adapted to decode data encoded in any conventional manner.
[0055] In the case of new files, the file construction application 211 copies the new file stored in the receiver spool directory 212 directly to the receiver work file system 204 and sends a notification of this to the receiver interface file system 201 . In the case of update files, the file construction application 211 reads the update file stored in the receiver spool directory 212 and reads the corresponding existing or “old” version of the file stored in the receiver work file system 204 and constructs a new version of the file in the receiver collector file system 202 . The file construction application 211 then deletes the update file from the receiver spool directory 212 and sends a notification of this to the receiver interface file system 201 .
[0056] [0056]FIGS. 8A and 8B illustrate how the replicated file receiver system 40 on each of the servers 50 at the mirror sites 60 works with both the new and old versions of a file. Referring first to FIG. 8A, assume for example, in an initial state, the receiver work file system 204 is storing one or more “old” files and that the receiver collector file system 202 is empty. At time T 1 , a first application process 218 submits an open request to open an old file (fname), and the receiver I/O library 215 outputs an appropriate system call such as open (old fname) to the receiver kernel 220 . At time T 2 , the receiver kernel 220 (mirror site file storing and serving device 40 operating system kernel) sends the open call to the receiver interface file system 201 . At time T 3 , the receiver interface file system 201 passes the open call to the receiver work file system 204 which responds to the call at time T 4 by returning a file descriptor (fd 1 ) to the receiver interface file system 201 . At time T 5 , the receiver interface file system 201 returns the file descriptor (fd 1 ) to the receiver kernel 220 and at time T 6 , the receiver kernel 220 returns the file descriptor (fd 1 ) to the first application process 218 . At time T 7 , the first application process 218 submits a read request to read the file (fd 1 ), and the receiver I/O library 215 outputs an appropriate system call such as read (fd 1 ) to the receiver kernel 220 . At time T 8 , the receiver kernel 220 sends the read call to the receiver interface file system 201 . At time T 9 , the receiver interface file system 201 passes the read call to the receiver work file system 204 which responds to the call at time T 10 by sending “old” data (fd 1 ) to the receiver kernel 220 (the “old” data passes through the receiver interface file system 201 ) and at time T 11 , the receiver kernel 220 sends the “old” data (fd 1 ) to the first application process 218 .
[0057] At time T 12 , an event is sent by the file construction application 211 indicating that a new version of the file name) has been created and stored in the receiver collector file system 202 . At time T 13 , a second application process 219 submits an open request to open the old file (fname), and the receiver I/O library 215 outputs open call open (old fname) to the receiver kernel 220 . At time T 14 , the receiver kernel 220 sends the open call to the receiver interface file system 201 . Because the receiver interface file system 201 is aware of the new version of the file fname) stored in the receiver collector file system 202 , at time T 15 , the receiver interface file system 201 generates and sends an open call open (new fname) to the receiver collector file system 202 and does not pass the open call open (old fname) to the receiver work file system 204 . At time T 16 , the receiver collector file system 202 by returns a file descriptor (fd 2 ) to the receiver interface file system 201 . At time T 17 , the receiver interface file system 201 returns the file descriptor (fd 2 ) to the receiver kernel 220 and at time T 18 , the receiver kernel 220 returns the file descriptor (fd 2 ) to the second application process 219 . At time T 19 , the second application process 219 submits a read request to read the file (fd 2 ), and the receiver I/O library 215 outputs a read call read (fd 2 ) to the receiver kernel 220 . At time T 20 , the receiver kernel 220 sends the read call directly to the receiver collector file system 202 , which responds to the call at time T 21 by sending “new” data (fd 2 ) to the receiver kernel 220 and at time T 22 , the receiver kernel 220 sends the new data (fd 2 ) to the second application process 219 .
[0058] As should now be apparent, when the receiver interface file system 201 becomes aware of a new file version in the receiver collector file system 202 , it modifies all open system calls from subsequent application processes and opens the new version of the file stored in the receiver collector file system 202 . Accordingly, all application processes generating open system calls prior to the creation of the new file version work with the receiver work file system 204 and read the old version of the file and all application processes generating open system calls after the creation of the new file version work with the receiver collector file system 202 and read the new version of the file. Consequently, if at time T 23 the first application process 218 submits another read request to read the file (fd 1 ), at time T 24 the receiver kernel 220 will send the read call to the receiver interface file system 201 which in turn will pass the read call at time T 25 to the receiver work file system 204 . Thus, old data (fd 1 ) will be returned to the first application process 218 .
[0059] Referring now to FIG. 8B, at time T 26 , the first application process 218 submits a close request to close the old file (fd 1 ), and the receiver I/O library 215 outputs a close call close (fd 1 ) to the receiver kernel 220 . If the first application process 218 is the last application process to closed the file, at time T 26 the receiver kernel 220 will send a cleanup event for old file (fd 1 ) to the receiver interface file system 201 . At time T 28 , the receiver interface file system 201 sends a command to the receiver kernel 220 to copy the new version of the file, which results copying of the new version of the file to the receiver work file system 204 at time T 29 . Thus, the new version of the file takes on the status of the “old” or existing version of the file in the receiver work file system 204 . The copying process is similar to the copying process described earlier in the discussion of the file replication and transfer system 10 .
[0060] At time T 30 , the second application process 219 submits a read request to read the file (fd 2 ), and the receiver I/O library 215 outputs a read call read (fd 2 ) to the receiver kernel 220 . At time T 31 , the receiver kernel 220 sends the read call directly to the receiver collector file system 202 , which responds to the call at time T 32 by sending new data (fd 2 ) to the receiver kernel 220 and at time T 33 , the receiver kernel 220 sends the new data (fd 2 ) to the second application process 219 .
[0061] At time T 34 , a third application process 221 submits an open request to open the old file (fname), and the receiver I/O library 215 outputs open call open (old fname) to the receiver kernel 220 . At time T 35 , the receiver kernel 220 sends the open call to the receiver interface file system 201 . At time T 36 , the receiver interface file system 201 sends the open call to the receiver work file system 204 . At time T 37 the receiver work file system 204 returns a file descriptor (fd 3 ) to the receiver interface file system 201 . At time T 38 , the receiver interface file system 201 returns the file descriptor (fd 3 ) to the receiver kernel 220 and at time T 39 , the receiver kernel 220 returns the file descriptor (fd 3 ) to the third application process 221 .
[0062] At time T 40 , the second application process 219 submits a close request to close the new file (fd 2 ), and the receiver I/O library 215 outputs a close call close (fd 2 ) to the receiver kernel 220 . If the second application process 219 is the last application process to closed the new file (fd 2 ) , at time T 41 the receiver kernel 220 will send a cleanup event for the new file (fd 2 ) to the receiver interface file system 201 . At time T 42 , the receiver interface file system 201 sends a command to the receiver kernel 220 to delete the new version of the file, which results in the deletion of the new version of the file from the receiver collector file system 202 at time T 43 .
[0063] While the foregoing invention has been described with reference to the above embodiments, various modifications and changes can be made without departing from the spirit of the invention. Accordingly, all such modifications and changes are considered to be within the scope of the appended claims.
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A file system for distributing content in a data network, includes a file replication and transfer system and a replicated file receiver system. The file replication and transfer system includes an interface file system which looks for changes made to contents of a file created and stored in an associated work file system; and a file system monitor communicatively associated with the interface filing system for monitoring events occurring with the interface file system and causing copies of the new files to be transferred over the data network to the replicated file receiver system. The interface file system also looks for changes made to the contents of files already stored in the work file system and creates an update file in a mirror file system if a change to the contents of a file stored in the work file system is observed by the interface file system. A collector file system communicatively associated with the mirror file system is provided for temporarily storing a copy of the update file. The replicated file receiver system includes a file construction system for constructing a new version of the file from a copy of the file and the update file; a receiver collector file system for storing the new version of the file; and a receiver interface file system for enabling work to be conducted with an old copy of the file if an open request for the file has been made prior to the construction of the new version of the file, and for enabling work to be conducted with the new version of the file if an open request for the file has been made after the notification that the new version of the file has been constructed.
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BACKGROUND OF THE INVENTION
Because of high cost of heating dwelling places, commercial establishments and the like, it has become essential to operate heating units in a more efficient manner to conserve high price fuels. A part of the solution to this problem is the more efficient storage of heat within the burner chamber during burner operation. By storing at least a part of the heat during the periodic burning stages, it is possible to then release at least a part of the heat in a more useful manner. Thus heat can be generated and can be expended in a controlled and therefore more economical fashion.
A major time of heat loss is during the burning operation when temperatures reach their peak and it is at that stage that heat is most likely to be lost to the system. Since, however, it is proposed in the present invention to absorb a greater part of the heat during the heating cycle and then expending the heat in a useful manner, a more efficient utilization is realized in this described manner.
It has been further found, that one of the major sources of heat loss is through the stack. While it appears that one "obvious" way to solve the problem is to provide a valve in the stack which would open during the heating operation and thereafter close, this has not proved to be a very practical way of preventing heat loss because there is heretofore not been devised a practical way of coordinating stack closure and stack opening with burner operation in a manner which could insure the free passage of exhaust gases through the stack during normal burner operation, allow purging of combustion gases after burner operation and then effect closure of the stack. All this must of course be automatic and should occur with unfailing certainty and in addition, effect closure of the flue in the event of power failure and automatic opening thereof when power is restored.
Consequently, the stack is closed, and automatically, except during actual firing and purging of possibly dangerous gases within the combustion chamber.
OBJECTS OF THE INVENTION
It is a principal object of the present invention to utilize in a more efficient manner the heat energy which is developed within the combustion chamber of a furnace of both gas fired and oil fired embodiments in order to effect greater economy of fuel usage.
It is another object of the present invention to provide thermal elements which absorb heat within the combustion chamber and then release such heat in a controlled and hence more efficient manner than previously.
It is another object of the present invention to provide an automatic control system in which the stack is automatically sealed against heat loss when the burner is not in operation; when the burner is in operation the stack is always kept in an open position. When the heating system transitions from heating to non-heating, the stack is automatically held open to allow for purging of any harmful, noxious gases and the like within the heating chamber, and after such purging is completed the stack is automatically closed and kept in that condition until the heat sensor calls for resumption of heating operation at which time the stack is reopened.
It is a further object of the present invention that automatically, and in response to a power failure, that always as the burner operation is discontinued, the stack is automatically resealed.
It is an overall object of the present invention, by means of the aforementioned control device, to reduce heat losses which occur by passage of hot air and other gases out of the stack.
Other objects and features of the present invention will become apparent from a consideration of the following description which proceeds with reference to the accompanying drawings wherein a selected example embodiment is chosen to illustrate the invention but is by no means restrictive thereof.
DRAWINGS
FIG. 1 is a side elevation view of a furnace shown partly in section and with the cold air ducts, heat ducts and stack incorporating the automatic check value in accordance with the present invention;
FIG. 2 is a section view taken on line 2--2 of FIG. 1;
FIG. 3 illustrates details of the check valve, check valve drive motor and position switches associated with the check valve for controlling the other portions of the control circuit;
FIGS. 4a-4f illustrate the main control circuit in successive conditions wherein FIG. 4a illustrates the control circuit when the thermostat first signals need for commencement of a heating operation and the check valve in the flue is closed; FIG. 4b is the next successive condition from 4a wherein the check valve within the flue starts to open and the thermostat is still signalling need for a heating operation; FIG. 4c illustrates the next condition of the control circuit in which the thermostat is still open and the check valve is fully open; FIG. 4d illustrates the thermostat terminating the heater cycle and the timer starts to run to produce a scavenging and runout time; FIG. 4e illustrates a power failure or fuse-blow condition which the system is deprived of power and the burner shut off; FIG. 4f illustrates the condition of 4e after the burner comes on following either power failure or failure of the fuse from the main power system.
FIG. 5 illustrates the superimposed curves, Temperature versus Time in a heating chamber having neither control system or thermal inertia elements and, the next curve illustrates Temperature versus Time (same scale) of the same chamber but with a control system including a flue value which prevents heat loss through the stack; the next curve is of the same chamber but with the heat storage (heat inertia elements) in the combustion chamber of FIG. 1 and without the control valve system to prevent heat loss through the stack; and the next curve is the same heating chamber of FIG. 5 illustrating Temperature versus Time but with a heating system incorporating both the thermal storage units of FIG. 1 and the control system of FIG. 3 including the stack check valve of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 3, there is illustrated a furnace 10 consisting of a sheet metal cabinet with an interior combustion chamber 14 surrounded by a jacket 16, footing 20 and a number of still support rings 22. At the lower end of the furnace is a combustion chamber 14 which may be either oil or gas fired. Surrounding the combustion chamber is a stone filler 30, a steel backing 32 and a quantity of fire brick 34. Above the footing are heat storage units 36 consisting of high heat absorption fire brick, vermiculite and the like, all of which is designed to receive a part of the heat which is generated within the combustion chamber 26, and to retain such heat after the firing operation is completed.
An opening 44 is provided for the burner which is energized and fed with combustible material in the form of gas, oil or the like.
The furnace has a cold air return 48 and heat ducts 54, 55, 56 through which hot air is circulated from the plenum 58.
The combustion product gases are vented to atmosphere through a stack vent duct 60 having an automatic check valve 62 and a barometric damper 64.
STACK CHECK VALVE
Referring to FIG. 3, the stack check valve 62 consists of a baffle or barrier 66 which is proportioned to substantially fill the cross section of the stack duct 60, the stack valve 62 being spring loaded by spring 69 to the closed position shown in FIGS. 1, 3 and is operated to an open position by means of a shaded pole driven motor 68 having a drive shaft 70 connection with the barrier or baffle 66 and includes an armature 74 and field windings 76. Also on shaft 70 are two mercury switches 80, 82 which are positioned responsive to the position of the baffle 66 such that mercury switch 80 is in closed ("on") position when the valve 66 is in its closed position and mercury switch 82 is open (position indicated in FIG. 3) when the stack valve is in the closed position shown in FIGS. 1, 3.
Certain circuits are made through the circuit of FIG. 3 to the control circuit illustrated in FIGS. 4a-4f so that the operation of the stack valve 62 coordinates with the operation of the burner under all conditions of operation.
CONTROL CIRCUIT
Referring next to FIG. 4a, the system is assumed to be with power, the sack valve 62 is closed, and the thermostat of the system signals the need for heat, a 115 volt line commencing with contact "5" of M-P-1 (FIG. 4a) through conductor 86, fuse 88, junction 311, conductor 313, the closed (normally opened) switch 90, conductor 92, junction 94, conductor 96, closed switch 98 (which is operated by a cam 100 in a manner later to be described), conductor 102 through switch 104 (which is normally open), junction 106, closed switch 108 (which is normally open), conductor 110 bypassing for the moment a high resistance 112 and conductor 114 and through conductor 116, junction 303 to conductor 118 and contact 4 in FIG. 4a of the male plug M-P-1.
From contact 4 FIG. 4a power is transmitted through female plug F-P-1 through contact 4, conductor 119, closed mercury switch 80, conductor 120 through the winding 76 of the shaded pole motor and the 115 volt return line 122 through contact 1 of F-P-1 to ground on the return side.
It is the action of the thermostat switch from contact 6 and 7 which closes the normally open switch 104 enabling the circuit described. Switch 104 closes because the thermostat switch through contact 6 and 7 acts through conductor 130, junction 215, conductor 217, relay 132 and conductor 134 to ground line 122 is energized to relay 132, conductor 134, ground 346, contact 1 of M-P-1 to effect closing of the normally open switch 104.
The switch 104 will remain closed to enable the circuit described by the control circuit through contacts 4 and 5 of M-P-1 until the thermostat relay is "off". When switch 104 is closed the relay 180 is energized through conductor 111 to ground 346, closing switches 108, 182 and 212. When the circuit is made as shown in FIG. 4a, power is communicated to the shaded pole motor (FIG. 3) (F-P-1) which will operate the check valve 62 to an open position. Once the shaded pole motor 68 moves the stack valve 62 to a full open position, the mercury switch 82 is then closed and mercury switch 80 opens and the circuit to the motor 68 is then next made in the same manner from contact 5, M-P-1 (FIG. 4a) through the same circuit as described, but commencing at conductor 110, through conductor 114, resistance 112 (consisting of 0.7 Henry and 250 ma), conductor 126 to contact 8 of M-P-1 FIG. 4b. From contact 8 of M-P-1 (FIG. 4b) contact is made through contact 8 of F-P-1 (FIG. 3) through conductor 154, junction 155, conductor 156, shaded pole motor windings 76 to ground line 122 and ground contact 1 (F-P-1). Thus much lower voltage is communicated to motor 68 keeping the valve 66 open against the spring force tending to close it.
BURNER TURN ON
The effect of closing the switch 82 and opening switch 80 with the check valve 66 now in full open position, is to energize the burner motor or solenoid valve in the case of gas operated furnace, this burning operation will continue as long as the thermostat signals the need for heat.
Referring to FIG. 4b the stack check valve 66 is kept open against the spring force tending to hold 66 in a normally closed position by means of contacts 5 to 8 (FIG. 4b) through resistance 112 and therefore the circuit to the shaded pole motor is through conductor 154, 156, junction 154 (FIG. 3) to ground line 122.
At the same time that the secondary circuit is made through contact 8 (FIG. 3) a power connection is made to the burner motor through contact 7 (FIG. 3), conductor 160 through closed mercury switch 82 and conductor 162 to contact 12 which is coupled to contacts 15, 17 and 18 when F-P-1 and M-P-1 are connected to make contact with the burner motor. Thus, in the conditions of FIG. 4b when the thermostat continuously calls for heat, and the check valve 66 is oepn, the burner motor will continue to actuate the oil burner or the solenoid valve and combustion will continue within the combustion chamber 14 heating the heat storage units 36 (FIGS. 1, 2) and the furnace will continue to distribute heat through the heat ducts 54, 55 and 56 with the cold air returning for recycling through duct 48. In the stack conduit 60 the automatic check valve 62 will continue to open under the described conditions.
THERMOSTAT OPENS
When the thermostat opens, the first thing that happens is that the burner discontinues operation but the valve 62 continues to remain open for a "purging stage" in the manner next to be described and in connection with FIGS. 4b, 4c, 4d. Commencing first with FIG. 4b, when the thermostat switch is opened through contact 7 the relay 132 is de-energized and the normally open switch 104 is opened. The moment the thermostat switch opens, the relay 132 permits the normally open switch 104 to open. Once the burner is shut off (which occurs automatically when the thermostat opens), the potential across the clock circuit 200 (FIG. 4c, 4d) is 115 volts, when the burner is shut off because the circuit from conductor 201 to contacts 6, 7, 9 and 10 is disabled, but when the burner is on there is 0 potential across the clock circuit 200. Thus, the clock circuit becomes operative commencing from the time when the burner is shut off by thermostat operation and a circuit is then created across the clock circuit commencing from contact 5, conductor 86, fuse 88, junction 311, conductor 313, junction 315, closed switch 90, conductor 92, junction 94, conductor 202 across the timing circuit 200, conductor 206, junction 208, conductor 210, closed switch 212 (which is normally open) conductor 214, junction 215, conductor 130 and contacts 6, 7, 9 and 10. Once the clock timer commences operation (FIG. 4d) the switch 218 is immediately closed and switch 220 is immediately opened, switches 218 and 220 being operated by means of cams 240 and 242 carried by shaft 244 of the clock drive mechanism.
Switch 98 is opened after approximately one minute by means of the cam 100 also on the shaft 244 and this causes the valve 66 to close. The delay in closing valve 66 enables the gases to be purged, this being commonly referred to as the scavenger time, i.e., time permitting the combustion chamber 14 to be emptied of noxious and other dangerous gases before the flue is closed to confine the chamber 14 against further heat loss.
Referring to FIG. 4c, a circuit continues to be made through contact 5, conductor 86, fuse 88, closed switch 90 (which is normally open), conductor 92, junction 94, conductor 96 and closed switch 98 until the closed switch 98 is opened by cam 100. Once the switch 98 is opened, however, this interrupts the circuit to shaded pole motor 68 through open switch 98, conductor 102, switch 182, junction 106, switch 108, conductor 110, conductor 114, resistance 112, conductor 121 and 126 to contact 8. The spring associated with valve 62 thus returns the valve 62 to closed position. The timer, however, continues to time (FIG. 4d) and to operate for an additional period of time as for example one minute only, this being referred to as the runout time and at the end of that period, switch 98 again closes by operation of the cam 100. During runout a circuit is made by contact 5, conductor 86, fuse 88, switch 90, conductor 92, junction 94, conductor 202, timer 200, conductor 206, junction 208, resistance 207, switch 218, conductor 201 and contacts 12, 15, 17 and 18 of M-P-1.
Switch 218 which at the beginning is open, is closed instantly at the time the clock drive commences by cam 240 and reopens at the end of the full timing cycle in order to permit a full runoff time and then terminates same. The circuit is made through switch 218, inasmuch as switch 212 is open when the relay 180 is de-energized by opening of switch 98 at the end of the one minute cycle by cam 100. The switch 220 opens instantly at the start of the cycle and is closed by operation of cam 242 at the very end of the cycle. The purpose of this is to disable the thermostat circuit until a complete timing cycle has run.
POWER FAILURE
Referring next to FIG. 4e, in the event of a power failure, there is a failure at contact 5 thus de-energizing the relay 300 and permitting closing of the normally closed switch 302 and 310. The normally open switch 90 is then opened and this has the immediate effect of closing the stack valve 62 thus preventing any circuit to the shaded pole motor either through contact 8 or through contact 4 to hold the valve open against the spring force biasing it closed. Thus, the first thing that happens is shutting the burner off, closing of the entire system, and immediate closure of the stack valve. In addition to the normally closed switch 302 closing, the normally open switch 90 opens, normally closed switch 310 closes, and normally open switch 312 opens. Thus, the thermostat is disabled, so that the thermostat cannot be reset by the opening of switch 312 and for a purpose which will next be explained so that when the power circuit comes on again there will be a delay preceded by opening of the stack valve.
When power is reinstituted, a circuit is made through the power line commencing from contact 5, conductor 86, fuse 88, junction 311, conductor 313, junction 315, conductor 319, closed switch 310 to the thermal relay 342 which after a three minute interval closes switch 347. A slave relay 344 is operated by thermal relay 342 through conductor 322, closed switch 347 (closed by 342) conductor 349 to relay 344 to effect closing of switch 360 which operates solenoid 300 closing the normally open switch 90, opening the normally closed switch 302, opening the normally closed switch 310 and closing the normally open switch 312. Because switch 302 is initially closed, a circuit is made upon initial power restoration through contact 4, conductor 86, conductor 370, switch 302, conductor 114 and conductor 118 to contact 4, resistance 112, conductor 121, 126 contact 8, conductor 154 (FIG. 3), conductor 156, winding 76, return 122 to energize the motor and open valve 66. Thus during the interval that power first comes on and the thermal relay timer, the motor to the valve 66 is operated but discontinues when switch 302 is opened by thermal relay 342 operation. The result is that a venting of gases from chamber 14 first occurs before any other event and then the system is ready for normal re-operation. Depending upon whether the thermostat is opened or closed, the burner will be operated and the valve 66 opened or closed in the previously described manner.
OPERATION
In operation, the control system and heat reservoir are intended for use with an intermittently operative gas or oil fired furnace. Referring to FIG. 5 which compares the invention usage with a furnace having neither the thermal storage elements or the control for the flue valve, it will be seen by comparing the curves which refer to a heating chamber of one or both or neither of the storage and control means that a combination of both the thermal storage units and the flue valve control will effect savings of 25% to 30% in fuel. That is, comparing the curves of the chamber both the check valve and the heat elements, it will be seen that the invention is effective for providing its same heating effect in a home with the same thermostat setting at a saving in furnace operation of between 25% and 30% of the fuel requirement for that furnace. This economy of operation will become clear from a consideration of the following more detailed description of operation.
During operation, heating within the burner chamber 14 will develop within about 15 to 30 minutes a cherry red condition of the heat storage units 36 (also referred to hereinbefore as heat inertia or heat flywheel elements). These units are in the nature of refractory brick or iron grating. Any material is satisfactory so long as it meets the functional requirement of having a high specific heat and is able to withstand exposure to the heat within heating chamber 14 without deterioration or excessive contraction and expansion.
Because the heat storage elements 36 receive heat and are available to give off the same heat following termination of the burner operation, it is possible to more efficiently utilize the heat which would otherwise be lost to the system.
Referring next to the control system which effects operation of the check valve 62 in an automatic manner whereby said check valve 62 is closed when the burner is deacturated and is opened during the burner operation with provision for purging of the combustion chamber for a specified period of time in the interval between deactuation of the burner and closing of the stack in order to rid the combustion chamber of explosive or otherwise noxious gases. A further safety feature of the valve operation is that it will automatically close should the system loose power and will automatically be reopened before the burner can commence reoperation once power is restored to the system. How these events occur will be next described.
In operation, referring to FIG. 4a, there will be described the condition when the thermostat signals a requirement for heat and the check valve 66 is in a closed position. It should be understood from referring to the male plug M-P-1 indicated in FIG. 4a, contacts 2 and 3 are associated with the thermostat circuit contacts 13, 14 and 16 are non-operative, contacts 6, 7, 9 and 10 constitute a part of the power line from the thermostat. Contact 5 is the power circuit, contact 1 is the return. Contacts 4, 8, 12, 15, 17 and 18 are interconnecting terminals. The reason for multiple contacts is to serve as a safety against overload conditions.
When the thermostat switch is closed a circuit is made through contacts 6, 7, 9 and 10 (FIG. 4a) through conductor 130 energizing relay 132 through the windings thereof and conductor 134 to the 115 volt return line 346. Relay 132 then closes normally open switch 104. A circuit is then made from the power line commencing with contact 5 conductor 86 through fuse 88, junction 311, conductor 313, junction 315, closed switch 90, conductor 92, junction 94, closed switch 98, conductor 102 through closed switch 104, junction 106 through the winding of relay 180 to ground 346 which in turn effects closing of switches 108 and 182 and closing switch 212. When switch 182 is closed a circuit is made through conductor 187 and closed switch 182 as well as through conductor 185 and closed switch 104 to junction 106, closed switch 108, conductor 110, 116, junction 303, conductor 118, contact 4 (FIG. 3), conductor 119, switch 80, conductor 120, motor 96, ground line 122.
The shaded pole motor 68 then turns the valve 66, against the resistance of the spring (not shown) about shaft 70 until it reaches a full open position whereupon the switch 80 opens and switch 82 closes. At this point the valve 66 becomes held in open position against the resistance of the spring by means of a much lower magnitude voltage as will be next described.
The circuit through contact 4 (F-P-1, FIG. 3) is broken because switch 80 opens in full open position of the valve 66 and therefore a new contact must be made between power line contact 5 of FIG. 4a (M-P-1) and this is accomplished by means of a circuit commencing with contact 5 through conductor 86, fuse 88, closed switch 90, conductor 92, junction 94, closed switch 98, either conductor 102, conductor 185 or conductor 187 and closed switches 104 or 182 to junction 106, closed switch 108, conductor 110, junction 111, conductor 114 through choke 112 or conductor 116, conductor 117, resistance 118 through conductor 121 and to contact 8 M-P-1 and then to F-P-1 contact 8 (FIG. 3). From contact 8 (F-P-1, FIG. 3) a circuit is made through conductor 154, winding 76 of the shaded pole motor to the ground 122 but the voltage and current which are transmitted to the shaded pole motor in this case is of much lower magnitude but sufficient to overcome the resistance of the spring tending to bias the valve 66 to a closed position and thus the valve is held in open position against the resistance of the spring by the lower magnitude of power communicated to the shaded pole motor.
At this time, whereas the mercury switch 80 becomes open and mercury switch 82 is closed, it should be clear that these two switches 80, 82 are position responsive mercury switches depending upon the condition of the valve 66, i.e., when valve 66 is closed switch 80 is closed and when valve 66 is open switch 80 is open and valve 82 becomes closed. When switch 82 is closed, a circuit is made from contact 7 (note that contacts 6, 7, 9 and 10 are all connected from power line from the thermostat relay and provides 115 volts, contact 5 leading to a 115 volt AC input in the control box).
When the thermostat calls for heat and the check valve 66 is open (referring to FIG. 4b) a circuit is made through contacts 6, 7, 9 and 10 M-P-1 to F-P-1 through conductor 160 (FIG. 3), closed switch 82, conductor 162 to contacts 12, 15 which are also connected to 17 and 18 through M-P-1 to contacts 17 and 18 of F-P-1 thereby energizing the burner.
This condition continues until the thermostat opens at which time (referring to FIG. 4c), immediately upon the thermostat opening the burner is deactuated by means of a circuit (not shown) which is part of the conventional control system.
Once this occurs, as indicated in FIG. 4c, a clock circuit designated generally by reference numeral 200 immediately has 115 volt potential across the timer.
Because of the potential which exists across the timer immediately upon deactuation of the burner the clock drive 200 is caused to operate since a potential exists in the line commencing from contact 5 through conductor 86, fuse 88, junction 311, conductor 313, junction 315, closed switch 90, conductor 92, junction 94, conductor 202 across the timer 200, conductor 206, junction 208, conductor 210, closed switch 212, conductor 214, junction 215, conductor 130 and one or the other of the burner contacts 6, 7, 9 or 10. During this time, a circuit continues to be made from contact 5 through contact 8 as well, to the shaded pole motor 76 maintaining the valve 66 in an open position.
The timer which includes three cams 240, 244 and 100 operating switches 218, 220 and 98 respectively, operates in such way that normally closed switch 220 is opened to disable the thermostat circuit commencing from contact 3 and conductor 324, closed switch 312, open switch 220 and conductor 323 back to connector 2.
The switch 220 is open until an entire cycling period for the timer motor and after such is completed the switch 220 is again closed which occurs at the end of the full timing period.
Switch 218 which is at the beginning open, is immediately closed by cam 240 and is held closed until the end of a complete clock cycle at which time it again opens to terminate the clocking circuit (note that after the purge cycle, which is much shorter than the total cycle, cam 100 causes switch 98 to open disabling the motor 76 and allowing valve 66 to close). After one minute of timing cycle which is known as the purging cycle, the switch 98 is opened thus disabling solenoids 132 and 180 opening the normally open switches 104, 198, 182 and 212. Because switch 218 remains closed, however, the timer continues to time through connector 5, conductor 86, fuse 88, junction 311, conductor 313, junction 315, closed switch 90, conductor 92, junction 94, conductor 202 across the timer 200, conductor 206, junction 208, resistance 207, closed switch 218, conductor 201 to one or the other of connectors 12, 15, 17 or 18 of M-P-1. The timer continues to run until an entire cycle is completed at which time switch 218 opens and the timing cycle is finished.
Referring to FIGS. 4e and 4f, if a power failure should occur of if fuse 88 should not operate, relays 180, 132, 302 are all disabled, the normally opened switches 108, 182 and 104 are opened, normally closed switch 302 closes, the normally closed switch 310 closes, the normally open switch 90 opens, the normally open switch 212 opens and the normally open switch 312 opens. Thus, the thermostat circuit is disabled, the burner is turned off, and the stack valve 66 is immediately biased to a closed position by the operation of the spring, thereby closing switch 80 (FIG. 3) and opening switch 82.
Referring now to FIG. 4f, when power is resumed, power from contact 5 (M-P-1) as shown in FIG. 4f creates a circuit from conductor 86, junction 371 through conductor 370, closed switch 302, junction 303 to conductor 119, contact 4 of M-P-1 to contact 4 of F-P-1 through conductor 119 (FIG. 3), switch 80, conductor 120, winding 76 of the shaded pole motor and ground line 122 thus causing the valve 66 to be biased against the resistance of the spring to an open position.
A circuit is also made from contact 5 through conductor 86, junction 371, fuse 88, junction 311, conductor 313, junction 315, conductor 319, normally closed switch 310, conductor 321 to the thermal switch 342 which, after an interval closes and completes the contact through 347 to the ground 346. A slave relay 344 then closes, making a circuit through junction 311, conductor 322, closed switch 347, conductor 349 to relay 344 closing switch 360 which is normally open, energizing relay 300 to close normally open switch 312 in the thermostat line, open normally closed switch 310, and open the normally closed switch 302, permitting the valve 62 to close. The circuit is now returned to the circuit condition indicated in FIG. 4a which is the circuit condition prevailing at the time the check valve is closed and in the event that a thermostat signals restart, the operation repeats as indicated described in FIGS. 4a, 4b.
The operation of the thermal storage elements and the control system described improves the furnace operation, conserving heat to the extent of 25% to 30%, while maintaining the same thermostat setting. This result is indicted from the curves indicated plotting temperature verus time in FIG. 5.
Although the present invention has been illustrated and described in connection with a few selected example embodiments, it will be understood that these are illustrative of the invention and are by no means restrictive thereof. It is reasonably to be assumed that those skilled in this art can make numerous revisions and adaptations of the invention and it is intended that such revisions and adaptations will be included witin the scope of the following claims as equivalents of the invention.
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In the heating chamber of the furnace are a number of heat-absorbing elements which serve as a thermal storage, absorbing some of the heat which is developed during the regular burning cycle and then releasing such heat for additional heating effect. Stored heat is available for additional and therefore more efficient heating. A control system is used to conserve heat by selectively and automatically opening and closing the stack to prevent heat loss in timed relation with the burning cycle and adapted to provide sufficient purge time. The stack valve opens automatically at the commencement of a burning cycle and thereafter automatically closes after a purge interval. In the event of a power failure, the stack valve automatically closes and reopens when power is restored prior to the commencement of any succeeding burning operation.
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This is a division of application Ser. No. 07/668,202, filed Mar. 12, 1991, now U.S. Pat. No. 5,182,912.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an apparatus for receiving and using the energy present in solar radiation. The invention relates more specifically to an apparatus used to preheat a working fluid for a subsequent solar dissociation reaction.
2. Description of the Related Art
It is well known to utilize blackbody devices for the absorption of solar energy. In order to create a solar absorption device that is economically feasible, many different collector arrangements and working fluids have been proposed. For example, U.S. Pat. No. 3,987,781 to Nozik discloses the use of a blackbody receiver surrounded by a transparent shell that is coated with cadmium stannate. The object of the invention is to transmit solar radiation and reradiate infrared radiation back into the receiver.
By virtue of this construction, the invention disclosed by Nozik allows the blackbody to absorb the solar radiation through the transparent shell, while somewhat alleviating the problem of reradiation from the blackbody to the surrounding atmosphere. It is important to note that this invention, and other prior art devices, provide for energy absorption in but a single stage.
Even with the use of a radiation-selective surface, reradiation is a problem at high working temperatures with conventional solar absorption receivers. Such is the case because the blackbody must become very hot in order to heat the working fluid to the desired temperature. The blackbody will then radiate large amounts of energy to any surface that is at a lower temperature than itself. The energy transferred, or lost, through reradiation is proportional to the temperature difference between the blackbody and any surrounding surfaces. Thus, the higher the blackbody temperature, the greater the losses that may be attributed to reradiation.
Although conventional blackbody and direct absorption receivers are satisfactory in certain respects, there are inherent limitations on the use of surface absorption of solar radiation to drive external heat engines. Specifically, the receiver cavity in such systems generally operates at a higher temperature than the working fluid driving the external heat engine, since a gradient is required to achieve the heat transfer from absorbing surface to working fluid. The efficiency of a blackbody or direct absorption receiver decreases with increasing temperatures due to reradiation in the infrared. Consequently, the increase in efficiency of the associated heat engine achieved at higher operating temperatures is ultimately offset or lost entirely in the system combination.
In addition, difficulties with absorbing-surface thermal stress can arise in the presence of high temperatures and light fluxes in conventional blackbody or direct absorption receivers, providing a serious limitation on the capability of such devices at elevated power levels.
Inventions that have as their objects the generation of electrical power through the absorption of solar radiation and subsequent dissociation of the halogen constituents of a working fluid include U.S. Pat. Nos. 4,848,087 and 4,945,731.
U.S. Pat. No. 4,848,087 entitled "Solar Augmented Power System" discloses an energy conversion system in which a focused beam of radiation is employed to induce a reactive substance to produce reaction products at elevated temperatures and pressures. The pressurized materials are then controllably exhausted and introduced into a means for converting the heat and pressure of the pressurized materials into other useful work.
U.S Pat. No. 4,945,731 entitled "Absorbing Fluid Receiver for Solar Dynamic Power Generation and Solar Dynamic Power System" discloses a receiver for a solar dynamic power system. The receiver has a hollow, cylindrical containment with a window for admitting solar radiation in the receiving space to heat a working fluid. The working fluid comprises a radiant energy absorber selected from halogens and interhalogens. Means are provided for coupling the working fluid with a heat engine for the purpose of generating electrical power.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an apparatus for more efficiently recovering the thermal, visible, and ultraviolet energy present in solar radiation.
It is an additional object of the present invention to provide an apparatus for preheating a working fluid for a subsequent solar dissociation reaction.
Further, it is an object of the present invention to provide an apparatus wherein the blackbody absorber is maintained at a relatively low temperature in order to minimize reradiation to the surrounding atmosphere.
Accordingly, the present invention provides an apparatus for preheating a working fluid prior to its direct exposure to solar radiation. The present invention will be described below in conjunction with two preferred embodiments. The first preferred embodiment has an optically transparent shell completely surrounding a blackbody absorber which is used for preheating. In the second preferred embodiment, the optically transparent shell only partially surrounds the blackbody portion, and is semicircular when viewed in cross section. For this reason, the second preferred embodiment is well suited to retrofit applications of existing fluid absorption receivers.
A fluid absorption receiver employing a light-absorbing fluid and an appropriate window configuration provides an alternative to direct absorption or conventional blackbody receivers, and affords a number of distinct advantages. Specifically, since the surfaces in the fluid absorption receiver can operate at temperatures lower than the light-absorbing fluid flowing through it, higher operating temperatures are achieved than in the more conventional design. The optimum selected high temperature fluid does not itself reradiate in the infrared, so cavity heat loss is kept to a minimum. Additionally, thermal energy loss from the fluid is minimized by the low rate of gas-to-surface heat transfer.
In both embodiments, the working fluid first passes through the blackbody receiver, absorbing thermal energy therefrom, then passes through the optically transparent portion for direct exposure to visible and ultraviolet solar radiation. This novel feature of the present invention allows the working fluid to absorb relatively large amounts of solar energy while the blackbody absorber remains at a relatively low temperature, thus minimizing energy losses through reradiation.
In each embodiment, the direct absorption of visible and ultraviolet solar radiation is used to dissociate the halogen components of a working fluid. The advantage of the present system is that it operates efficiently at a relatively low receiver temperature. Consequently, a rather conservative concentration ratio of approximately 100 may be employed, thus eliminating the need for either an advanced reflector and optics design, or a precision pointing system. In addition, the relatively high temperature of the working fluid with minimal reradiation loss makes the invention compatible with advanced power conversion systems such as Stirling or Brayton cycle engines.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features, and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiments, the appended claims, and the accompanying drawings. As depicted in the attached drawings:
FIG. 1 shows the absorption spectra of simple dihalogens of interest.
FIG. 2 shows the absorption spectra of inter-halogens of interest.
FIG. 3 depicts the solar spectrum; FIGS. 4-6 depict the portion of the spectrum passing through three 1 cm deep cells containing Cl 2 , Br 2 , and I 2 .
FIGS. 7 and 8 depict the total absorption, including all wavelengths, of solar energy through two binary mixtures of Cl 2 /I 2 and I 2 /Br 2 .
FIG. 9 shows the spectral broadening that occurs for chlorine at high temperatures and pressures.
FIG. 10 depicts a double-flow fluid absorption receiver with two vacuum jackets to prevent reradiation losses.
FIG. 10(a) is a cross sectional view of the first preferred embodiment.
FIG. 11 is a theoretical graph of temperature of the blackbody surfaces and the working fluid as it passes through the receiver of the first preferred embodiment.
FIG. 12 is perspective view of the second preferred embodiment in partial section.
FIG. 13 illustrates how the second preferred embodiment may be situated with respect to an existing solar receiver and reflector.
FIG. 14 is a process diagram of a binary solar field concept employing the halogen loop of the present invention.
FIG. 15 is a graph illustrating the efficiency of a Solar Kinetics T-700A conventional blackbody absorber as compared with that of the present invention, or RAFT Receiver, at various fluid outlet temperatures.
FIG. 16 is a graph illustrating the efficiency of the present invention as compared with conventional devices.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be discussed in terms of the currently perceived preferred embodiments thereof.
By way of example, the present invention will be described in connection with halogens, interhalogens, and an inert gas.
A fundamental aspect of the present invention is the dissociation of halogen molecules contained in a working fluid. When halogen molecules are exposed to sunlight, a portion of the incident radiation dissociates the diatomic molecules in the reaction:
X.sub.2 +photon→2X
where X represents a halogen molecule. Since the photon energy absorbed is very high on a molar basis, the potential exists for significant gas heating when the energy is released upon recombination.
The reaction is carried out in the presence of a buffer gas to ensure efficient transfer of the chemical energy stored in the dissociated atoms into thermal energy without reradiation.
The working fluid is a mixture of halogens such as Cl 2 , Br 2 , and I 2 in an inert buffer gas such as argon or helium. The working fluid flows through a receiver through which concentrated sunlight enters. In the receiver, the ultraviolet and visible portions of the solar spectrum are absorbed very efficiently by the halogens, which then transfer that energy, via collisions, to the buffer gas. FIG. 1 shows the absorption spectra of the halogens of interest.
Halogen dissociation and the possible resultant formation of interhalogens such as IBr, ICl or BrCl may have an effect on the thermodynamic efficiency of the cycle. The interhalogens also absorb the UV and visible portion of the spectrum, however, so their formation may not necessarily degrade performance (FIG. 2).
The buffer gas, which is a monatomic gas, does not reradiate in the infrared, nor do the halogens. The infrared portion of the solar spectrum is not absorbed by the halogen working fluid and thus penetrates through the receiver cavity. A method of recovering this remaining energy is discussed later. The solar spectrum and the portion of the spectrum passing through three 1 cm deep cells containing Cl 2 , Br 2 , and I 2 are shown in FIGS. 3 through 6 respectively.
These figures indicate a strong match between the solar spectrum and the absorption spectra of the halogens; this is the basis of the present invention. By proper selection of the working fluid mixture composition, it is possible to maximize the absorption of solar energy. Moreover, thermodynamic considerations indicate that temperatures on the order of 1700° C. are achievable. The limiting temperature is determined by the dissociation of the molecular halogen. The first significant dissociation of iodine occurs at a temperature of approximately 1400° C.; chlorine and bromine begin to dissociate at an even higher temperature.
The absorption of solar energy through two binary mixtures of Cl 2 /I 2 and I 2 /Br 2 is shown in FIGS. 7 and 8. These figures indicate that an appropriate combination of gases can be used to optimize the absorption. The ideal composition would be one which maximizes the absorption of the visible portion of the spectrum. It currently appears that a mixture comprising Ar/Br 2 /I 2 /Cl 2 in the volumetric proportions of 0.75/0.1/0.1/0.05 yields nearly optimum results.
The spectral absorption at high temperatures and pressures indicate that as the temperature increases, the absorption band widens, but the peak tends to be lower. FIG. 9 illustrates the spectral broadening that occurs for chlorine.
As previously noted, the halogens absorb only the visible and ultraviolet portions of the solar spectrum (below about 750 nm). Table 1 shows the percent of the solar spectrum that is at wavelengths shorter than a given lambda. The table also shows that about 50% of the solar energy is above 750 nm.
TABLE 1______________________________________Percent of Solar Constant at WavelengthShorter Than Lambda.λ, μm D(0 - λ) λ, μm D(0 - λ) λ, μm D(0 - λ)______________________________________0.12 0.00044 0.550 29.380 1.000 69.4880.20 0.00811 0.575 32.541 1.100 74.4350.25 0.1944 0.600 35.683 1.200 78.4040.28 0.5644 0.630 39.270 1.400 84.3310.30 1.2107 0.650 41.550 1.500 86.6390.35 4.517 0.700 46.879 1.700 90.2610.40 8.725 0.750 51.691 1.900 92.6440.45 15.14 0.800 56.023 2.500 96.2900.475 18.921 0.850 59.899 4.000 99.0580.500 22.599 0.900 63.365 5.000 99.5110.525 26.059 0.950 66.556 10.000 99.937______________________________________
This infrared energy would penetrate through the halogen/buffer working fluid mixture and reach the inner surface of the receiver. Obviously, the overall efficiency of such a system could be nearly doubled if this energy could be used to heat the halogen/buffer working fluid. The best way to make use of this portion of the transmitted solar flux is to select the material of the inner surface so that it absorbs infrared energy. This energy can then be conducted into the halogen/buffer working fluid by flowing the working fluid through the infrared receiver. The infrared receiver would conduct the thermal energy as a heat exchanger to the working fluid. By using this additional energy, the overall receiver efficiency could be boosted to nearly 100%.
To avoid reradiation loss in the system, the receiver structure in contact with ambient atmosphere, must be maintained at a low temperature. In other words, the receiver cavity must be insulated from the high temperature working fluid. This can be accomplished by surrounding the receiver in a transparent vacuum jacket. This material is selected based on its transmission spectra and operating temperature. The candidate materials include fused silica and crystalline quartz. The transmission properties are all over 90% and remain flat from the near UV to over 2.3 um. The maximum service temperature for each is higher than 800° C.
The fact that the halogen fluid directly absorbs the solar energy without reradiating it is the major advantage of the present system, compared with conventional solar receivers in which reradiation loss is a limiting factor in the operating efficiency of the collector. This advantage also leads to several other important attributes.
First, because of the receiver structure's low operating temperature, there is no need for a small aperture, thus allowing a relatively large window area to be utilized. This in turn translates into a low concentration ratio. A low concentration ratio system is much more forgiving of concentrator surface slope errors and is therefore much easier and much more economical to fabricate.
Second, a low concentration ratio system is also more forgiving of tracking and pointing errors, simplifying the overall requirements of the optical system.
Third, the lack of significant reradiation means that the gas working fluid of the present system can operate at much higher cycle temperatures than can be achieved by conventional systems. This allows higher efficiencies, and a smaller, higher temperature radiator.
Fourth, the present system may also utilize various energy conversion techniques for electrical energy generation. In some systems (closed Brayton or Stirling cycle) the absorbing fluid may serve as the working fluid in the power conversion unit. In another embodiment, a heat exchanger may be utilized to transfer the heat into another working fluid cycle (closed Rankine cycle). Furthermore, the high temperatures obtainable with this system suggests other, possibly more efficient, conversion schemes such as thermo-electric, topped dynamic cycles or even thermionic conversion.
FIG. 10 depicts a double-flow fluid absorption receiver with two vacuum jackets to prevent reradiation losses. This design incorporates existing technology: the inner portion is a modification of a state-of-the-art conventional blackbody receiver and a heat exchanger; the outer, optically transparent, quartz portion provides for direct fluid absorption.
In one possible embodiment, the receiver could be coupled with a trough solar collector, energy converter, and a heat rejection system. The receiver may also be utilized vertically around the perimeter of the "hot" section of a power tower which could be located centrally in a heliostat field.
In the first preferred embodiment, the fluid absorption receiver comprises a working fluid comprising a radiant energy absorber selected from the group consisting of halogens and interhalogens, and a buffer gas. The receiver also comprises a hollow, cylindrical containment for containing the working fluid having a first end, and a second end, and a hollow, cylindrical vacuum containment for insulating the cylindrical containment and admitting solar radiation having a first end, a second end, a transparent inner wall, and a transparent outer wall.
Additionally, the receiver comprises a hollow, cylindrical member, disposed within the cylindrical containment, having an inner wall and an outer wall, and defining an annular working fluid flow space comprising heat exchange means within the containment. Surrounding the cylindrical member for the purpose of providing insulation is a hollow, cylindrical vacuum containment having a first end, a second end, and a transparent outer wall. Means are also provided for coupling the heated working fluid with a heat engine.
FIG. 10 illustrates the fluid receiver 1 of the first preferred embodiment of the present invention. The working fluid is introduced into central conduit 4 at inlet 2. A bellows may be included as indicated at 3 to account for thermal expansion. Central conduit 4 contains heat exchanger 6, as depicted in the cross-section of FIG. 10(a), through which the working fluid flows. Heat is absorbed by blackbody coating 8 on the outside of central conduit 4. This energy is then conducted to the working fluid by means of heat exchanger 6. Central conduit 4 is insulated by means of cylindrical vacuum jacket 10 surrounding central conduit 4. The entire central conduit 4 is surrounded by quartz receiver 12 which is, in turn, insulated by outer vacuum jacket 14.
The preheated working fluid exits the central conduit and enters annular space 16 between central conduit 4 and quartz receiver 12. The working fluid is conducted through annular space 16, directly exposed to visible and ultraviolet radiation and absorbs further energy in a dissociation reaction. Reradiation is prevented by buffering the gas in an inert gas so as to ensure that excited halogen dissociation products are quenched and return to their molecular ground state after undergoing collisions which remove some of the absorbed solar energy. The working fluid exits at outlet 18 and is conducted to a means for coupling the working fluid with a heat engine.
In another embodiment, the outer surface of cylindrical vacuum jacket 10 may have affixed to its surface a baffle oriented in a spiral configuration around the length of its axis. The purpose of the baffle is to prevent laminar flow in annular space 16, thus ensuring that mixing and the associated enhanced heat transfer occurs.
FIG. 11 is a graph which depicts the relatively low temperature of blackbody coating 8 with respect to flow of the working fluid through the present invention. By allowing a lower temperature of blackbody coating 8, the present invention limits reradiation losses.
FIG. 12 illustrates the second preferred embodiment of the present invention. In the second preferred embodiment, the quartz receiver does not completely surround the blackbody and is therefore more suitable for retrofit applications on existing blackbody absorber systems. The optically transparent shell only partially surrounds the blackbody portion, and defines a semicircular containment when viewed in cross section.
In the second preferred embodiment, the fluid absorption receiver comprises a working fluid comprising a radiant energy absorber selected from the group consisting of halogens and interhalogens, and a buffer gas. The receiver also comprises a hollow, semicircular containment for containing the working fluid having a first end and a second end, and a hollow, semicircular vacuum containment for insulating the semicircular containment and admitting solar radiation having a first end, a second end, a transparent inner wall, and a transparent outer wall. Means are also provided for coupling the heated working fluid with a heat engine.
A synthetic oil or similarly suitable fluid is introduced into existing blackbody absorber 30. The outlet (not illustrated) of blackbody absorber 30 is in communication with a conventional heat exchanger. Quartz receiver 32, separated from the blackbody absorber by an air space, contains a working fluid comprising halogens, interhalogens, or mixtures thereof, and a buffer gas.
The second preferred embodiment can utilize vacuum insulation techniques similar to the first preferred embodiment. Also, solar energy may be focused on the invention as disclosed in either preferred embodiment by any appropriate means. For example, light may be focused by a single parabolic reflector (see FIG. 13) or by many reflectors arranged either in proximity to, or at a distance from, the receiver.
In the third preferred embodiment, the present invention may function in a retrofit mode by providing a binary solar field application. In this embodiment, the fluid absorption receiver superheats steam produced from a conventional blackbody receiver, thus reducing, or eliminating, the use of supplemental natural gas.
FIG. 14 depicts a binary solar field concept employing the halogen loop of the present invention. In the first, or conventional high temperature fluid loop of the binary installation, a fluid is heated from 305° C. to 345° C. based on 70% of the insolation in a solar field. The high temperature fluid is heated by means of a conventional blackbody absorber, and then exchanges the recovered heat to raise steam in a steam generator.
In the second loop of the binary solar field embodiment, the halogen or interhalogen/buffer gas working fluid of the present invention is heated from 425° C. to 535° C. based on 30% of the insolation in a solar field. This fluid then exchanges its recovered heat in a steam superheater to superheat the conventionally-generated steam from 315° C. to 510° C. The superheated steam is then utilized in a steam turbine for power generation.
Advantages of the binary field application include lower thermal fluid temperatures and the associated elevation in steam superheat temperatures; elimination of excessive thermal stress; an increase in system operating efficiency; a reduction in natural gas costs; and minimal capital investment.
FIG. 15 is a graph which depicts the efficiency of a Solar Kinetics T-700A conventional blackbody absorber as compared with that of the present invention at various fluid outlet temperatures. The present invention is referred to herein as a "RAFT Receiver," for Radiation Augmented Fluid Technology Receiver. As the graph illustrates, a blackbody absorber utilizing synthetic oil as working fluid is capable of a maximum efficiency of only 60%, since the oil is thermally unstable, thus limiting the outlet operating temperature to 325° C.
FIG. 16 is a graph which depicts the efficiency of the RAFT Receiver of the present invention as compared with conventional devices. Most importantly, the figure indicates the significance of radiation losses in line-focus receivers. At high operating temperatures, the efficiency of conventional devices drops dramatically as a result of reradiation, even when a selective surface is used. The fluid absorption receiver of the present invention does not exhibit this dramatic drop in efficiency, however, since the blackbody portion is at a much lower temperature as a result of the two-stage design. Consequently, reradiation losses are minimized, and efficiency is maximized.
While the present invention has been disclosed in connection with the preferred embodiments thereof, it should be appreciated that there may be other embodiments of the present invention which fall within the spirit and scope of the present invention as defined by the appended claims.
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Disclosed are an apparatus and method used to preheat a working fluid for a subsequent solar-driven dissociation reaction. The working fluid is first passed through a blackbody receiver where it absorbs thermal energy, and is subsequently exposed to direct solar radiation. The present invention allows the working fluid to absorb relatively large amounts of solar energy at elevated temperatures, while the blackbody absorber remains at a relatively low temperature, thus minimizing energy losses through reradiation and enhancing the efficiency of the overall energy exchange.
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RELATED APPLICATION DATA
This application is a divisional of U.S. application Ser. No. 11/373,952, filed Mar. 13, 2006, which is hereby incorporated herein in its entirety by reference.
TECHNICAL FIELD OF THE INVENTION
The present invention is in the field of hybrid vehicles, such as hybrid electric vehicles.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to an environmental friendly vehicle. More particularly, the present invention relates to hybrid vehicles, such as hybrid electric vehicles (HEVs).
Hybrid electric vehicles include an internal combustion engine and at least one electric motor powered by a battery array. The HEV of the present invention uses an engine in combination with an electric motor. An energy storage device is also used to store energy for driving the electric motor. The engine, preferably in conjunction with a generator (for series drive embodiment or without for a parallel embodiment), and the energy storage device work in combination to provide energy for powering the vehicle motor. A series HEV typically uses an engine with a generator (APU/PPU) to supply electricity to the motor and the energy storage system. A parallel HEV has a direct mechanical connection between the engine and the wheels. The use of electric power substantially cuts down on chemical emissions and vastly improves fuel economy.
In a parallel type hybrid electric vehicle, both the internal combustion engine and the electric motor are coupled to the drive train via mechanical means. The electric motor may be used to propel the vehicle at low speeds and to assist the internal combustion engine at higher speeds. The electric motor may also be driven, in part, by the internal combustion engine and be operated as a generator to recharge the battery array.
In a series type hybrid electric vehicle, the internal combustion engine is used only to run a generator that charges the battery array. There is no mechanical connection of the internal combustion engine to the vehicle drive train. The electric traction drive motor is powered by the battery array and is mechanically connected to the vehicle drive train.
Although HEVs have been previously known, the HEV technology of the present invention provides significant advantages of providing a viable HEV technology that allows for a high performance HEV with a unique management of the charge and energy distribution system.
Other features of the invention will become apparent as the following description proceeds and upon reference to the drawings.
In general terms, the present invention includes an energy storage system, the energy storage system adapted to accept energy so as to be capable of discharging and accepting energy through a series of discharge and energy acceptance events, and having a maximum energy state level and an actual minimum energy state level; and wherein the power unit and the energy storage system provide electricity to the electric motor for powering the vehicle; and an energy storage controller programmed to control the energy storage system by setting an artificial minimum energy state level to an initial level above the actual minimum energy state level, and, during a series of discharge and energy acceptance events, to be able to adjust the artificial minimum energy state level such that:
(a) in the case where a discharge and energy acceptance event results in the acceptance of insufficient energy to replenish the energy storage system to the maximum energy state level, the artificial minimum energy state level is raised; and
(b) in the case where a discharge and energy acceptance event results in the acceptance of sufficient energy to replenish the energy storage system to the maximum energy state level, the artificial minimum energy state level is lowered.
The energy storage controller preferably is further programmed to control the energy storage system by restricting the raising of the artificial minimum energy state level beyond a predetermined level below the maximum energy state level. It is also preferred that the energy storage controller is further programmed to control the energy storage system by restricting the lowering of the artificial minimum energy state level beyond a predetermined level above the actual minimum energy state level.
The energy storage system may comprise energy storage systems of any type capable of energy discharge acceptance events such as those selected from the group of: (1) at least one ultracapacitor and (2) at least one hydraulic cylinder. The energy storage system may also comprise an internal combustion engine and a generator adapted to provide energy to the energy storage system, such as electric energy.
The present invention also includes a method of controlling an energy storage system, the method comprising: providing an energy storage system electrically coupled to a power conversion device, the energy storage system adapted to recapture energy from the power conversion device so as to be capable of discharging and recapturing energy through a series of discharge and energy acceptance events, and having a maximum energy state level and an actual minimum energy state level; and the energy storage system providing energy to the power conversion device, and the power conversion device adapted to supply energy to the energy storage system; and an energy storage controller programmed to control the energy storage system by setting an artificial minimum energy state level to an initial level above the actual minimum energy state level, and, during a series of discharge and energy acceptance events, to be able to adjust the artificial minimum energy state level such that:
(a) in cases where a discharge and energy acceptance event results in the acceptance of insufficient energy to recharge the energy storage system to the maximum energy state level, raising the artificial minimum energy state level; and
(b) in cases where a discharge and energy acceptance event results in the acceptance of sufficient energy to recharge the energy storage system to the maximum energy state level, lowering the artificial minimum energy state level.
The present invention also includes a method and apparatus by which power is controlled in a hybrid electric vehicle such that high levels of performance and efficiency are realized. The invention relates specifically to the alternate energy source and optimization of its use.
The present invention includes a method and apparatus developed to optimize the use of energy in a hybrid vehicle application from the hybrid energy storage device.
The method and apparatus of the present invention is particularly useful with energy storage devices where the state of charge is readily determined by an easily measured attribute. Ultracapacitors and hydraulic storage cylinders are examples of the types of energy storage devices to which the present invention may be applied.
The state of charge, or energy level, is proportional to the voltage of the ultracapacitor or the pressure of the hydraulic cylinder. The method and apparatus of the present invention is particularly well-suited to hybrid vehicle applications where the hybrid power is primarily utilized during acceleration and deceleration.
The present invention is particularly well-suited to hybrid electric vehicle applications where the hybrid power is primarily used during acceleration and deceleration. The method includes three fundamental features which may be illustrated with respect to a parallel hybrid electric vehicle using storage of the type described above: (1) energy is expended from the hybrid energy storage device at a predetermined rate until a minimum energy level target is reached, whereupon the energy storage device is later replenished with energy from the vehicle. There is an equilibrium of energy expended to that replenished that will result; (2) the minimum energy target is continuously adjusted such that that equilibrium can be maintained at a higher power state of the storage device; and (3) replenishing the energy storage device with both the kinetic energy from the vehicle while decelerating, and with energy drawn from the primary power source of the vehicle during opportune events (i.e., typically when the vehicle is cruising or coasting, such as when moving downhill or otherwise not in need of accelerating power).
In one aspect of the invention, during vehicle acceleration, when hybrid energy is desired, energy is expended from the hybrid energy storage device at a pre-determined rate until a target minimum energy level is reached. Subsequently, during deceleration the recapture of energy from the kinetic energy of the vehicle to replenish the storage device is maximized. The more energy recovered in the energy storage device prior to a given acceleration event, the more energy that can be expended in that acceleration event.
In contrast to earlier methods, the method of the present invention features a system that is self-adjusting and will seek equilibrium with the energy balance of what is expended and replenished. The method of the present invention does not utilize fixed relationships between the hybrid storage level and vehicle state such as, for example, energy level and vehicle speed. Accordingly, changes to the energy and power requirements of the vehicle due to variations in terrain, drive cycle, vehicle weight, tire pressure, and the like will not adversely affect its performance. The hybrid drive following the minimum target level strategy will naturally adjust its contribution to maintain consistent vehicle performance and operator/passenger feel.
The rate at which energy is expended from the energy storage device may be any rate, so long as it is consistent.
The present invention also includes the adjustment of the minimum energy target level continuously so the energy storage device and corresponding power conversion system maintain a higher power state at equilibrium. For the energy storage devices described herein, the power is a product of the potential and flow. Accordingly, for a given flow, a higher potential will provide higher power.
There are two advantages to maintaining a higher potential. First, available hybrid power will be more consistent with peak power despite drive cycles with low vehicle kinetic energy. Second, for powers less than peak power of the system, a higher potential means less flow required. For energy storage devices such as Ultracapacitors and hydraulic cylinders, and the corresponding power conversion systems, lower flow means less energy loss as heat and thus higher efficiency. In addition, lower heat loss means that cooling systems do not work as hard.
In operation, each time the hybrid vehicle comes to rest at zero speed, and accounting for settling time of the storage device, the energy level of the storage device can be evaluated to see if the level has reached maximum capacity. If not, the minimum energy target level can then be raised. If so, the minimum target level can be lowered. This process repeats until equilibrium is reached. Anticipating disruptions to equilibrium will maximize the effectiveness of the strategy.
In another aspect of the invention, the higher energy level of the storage device prior to acceleration, the more that can be expended by way of hybrid assist. Striving for maximum hybrid contribution, two approaches as presented for increasing the amount of energy available prior to an acceleration event, beyond what is recovered during vehicle deceleration with regenerative braking.
One approach is to “siphon” power from the primary power source while it is operating at high efficiency or while it could be made to operate more efficiently. That is, to charge the energy storage system from the primary power source at a nominal rate that is just enough so as not to drastically alter its operation. Examples of operating points ideally suited for siphoning include when the vehicle is cruising at a steady state where fuel economy is relatively high and when the vehicle is stopped with the engine at idle doing little work with fixed operating overhead.
A small siphon charge over a period of time can significantly increase the energy level of the storage device. As a means to preserve storage capacity for the vehicle deceleration with regenerative braking, a target energy level is set below which siphoning is permitted. The target energy level is established in some relation to the kinetic energy of the vehicle.
The other approach is to simulate the drag normally associated with internal combustion engines at closed throttle through the use of regenerative braking. By applying a moderate level of regenerative braking when the operator lifts from the accelerator pedal, the vehicle will decelerate slightly and the energy storage device will be charged at a low rate.
The present invention allows for consistency in the power output during acceleration which is proportionate to apparent power demand.
The method and apparatus of the present invention feature the function of certain algorithms for system control. These algorithms use real-time inputs from the vehicle systems and provide real-time outputs for control of vehicle systems. The principal function of the present invention is to supplement the primary power source in a manner that is relatively transparent to the operator while preserving standard, consistent vehicle performance. This allows for consistent feel to the operator and the passengers as the vehicle accelerates and decelerates.
The present invention features a control algorithm that maintains the state of charge of the energy storage device (such as one or more ultracapacitors) within a pre-determined range as the vehicle proceeds through a number of energy expending and recapture events which may involve net energy loss or net energy gain.
The present invention is an improvement over the technology described in U.S. Pat. Nos. 6,484,830 and 6,651,759, which are hereby incorporated herein by reference, and which may be used with hybrid electric vehicles and drive systems as described therein as an example.
In general terms, the present invention includes a hybrid electric vehicle comprising a drive train; an electric motor for driving the drive train; a power unit electrically coupled to the electric motor; an electric energy storage system electrically coupled to the electric motor, the electric energy storage system adapted to recapture energy from the braking of the vehicle so as to be capable of discharging and recapturing energy through a series of discharge and energy recapture events, and having a maximum charge level and an actual minimum charge level; and wherein the power unit and the electric energy storage system provide electricity to the electric motor for powering the vehicle; and an electric energy storage controller programmed to control the electric energy storage system by setting an artificial minimum charge level to an initial level above the actual minimum charge level, and, during a series of discharge and energy recapture events, to be able to adjust the artificial minimum charge level such that: (a) in the case where a discharge and energy recapture event results in the recapture of insufficient energy to recharge the electric energy storage system to the maximum charge level (e.g., the energy discharged in an acceleration and the energy recaptured from braking after that acceleration), the artificial minimum charge level is raised; and (b) in the case where a discharge and energy recapture event results in the recapture of sufficient energy to recharge the electric energy storage system to the maximum charge level, the artificial minimum charge level is lowered.
It is preferred that the electric energy storage controller is further programmed to control the electric energy storage system by restricting the raising of the artificial minimum charge level beyond a predetermined level below the maximum charge level.
It is preferred that the electric energy storage controller is further programmed to control the electric energy storage system by restricting the lowering of the artificial minimum charge level beyond a predetermined level above the actual minimum charge level.
The present invention may be applied to any energy storage system, although, in the case of a hybrid electric vehicle, it is preferred that the energy storage system is a bank of Ultracapacitors, and that this system be used in association with an internal combustion engine and a generator adapted to charge the energy storage system with electrical energy.
Another aspect of the present invention is a hybrid electric vehicle comprising a drive train; an electric motor for driving the drive train; a power unit electrically coupled to the electric motor; an electric energy storage system electrically coupled to the electric motor, the electric energy storage system adapted to recapture energy from the braking of the vehicle so as to be capable of discharging and recapturing energy through a series of discharge and energy recapture events, and having a maximum charge level and an actual minimum charge level having a working range therebetween and which working is defined at its lower end by an artificial minimum charge level; and wherein the power unit and the electric energy storage system provide electricity to the electric motor for powering the vehicle; and an electric energy storage controller programmed to control the electric energy storage system by setting an artificial minimum charge level to an initial level above the minimum charge level, and, during a series of discharge and energy recapture events, to be able to adjust the artificial minimum charge level such that the working range of the electric energy storage system is biased toward the maximum charge level over the series of discharge and energy recapture events.
The present invention also includes a method of controlling an energy storage system, the method comprising: providing an electric energy storage system electrically coupled to the electric motor, the electric energy storage system adapted to recapture energy from the braking of the vehicle so as to be capable of discharging and recapturing energy through a series of discharge and energy recapture events, and having a maximum charge level and an actual minimum charge level; and wherein the power unit and the electric energy storage system provide electricity to the electric motor for powering the vehicle; and an electric energy storage controller programmed to control the electric energy storage system by setting an artificial minimum charge level to an initial level above the actual minimum charge level, and, during a series of discharge and energy recapture events, to be able to adjust the artificial minimum charge level such that: (a) in the case where a discharge and energy recapture event results in the recapture of insufficient energy to recharge the electric energy storage system to the maximum charge level, raising the artificial minimum charge level; and (b) in the case where a discharge and energy recapture event results in the recapture of sufficient energy to recharge the electric energy storage system to the maximum charge level, lowering the artificial minimum charge level.
The method of the present invention thus maintains the charge level of the energy storage device, such as an ultracapacitor, at a level in the higher end of the charge range over time.
Other objects, features, and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many modifications and changes within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of an energy storage system describing the extent of the charge and discharge of the energy storage system as it proceeds through a series of energy discharge and recapture events.
FIG. 2 is a schematic of an energy storage system describing the extent of the charge and discharge of the energy storage system as it proceeds through a series of energy discharge and recapture events while being controlled by the method and system of one embodiment of the present invention.
FIG. 3 shows a schematic of a hybrid electric vehicle in accordance with one embodiment of the present invention.
FIG. 4 is a schematic representation of the control nodes that may be used in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the foregoing summary of the invention, the following presents a detailed description of the preferred embodiments, which are considered to be the best mode thereof.
Energy storage devices like the ultracapacitor and hydraulic cylinder can be charged or discharged only with a change in energy potential. Energy storage is typically sized for the recapture of vehicle (system) kinetic energy from some maximum speed, representing a full charge event, referred to herein as an energetically favorable event.
A full discharge/charge event of the energy storage device will utilize the absolute maximum and minimum energy levels (potentials) of the device. This is the full working range of the device. Partial discharge/charge events will utilize only a portion of the full working range. These typically will be events wherein the energy expended will be only partially replaced by the energy recaptured during regenerative braking, referred to herein as an energetically disfavorable event. The working range of partial discharge and charge events will tend toward the absolute minimum potential of the energy storage. The present invention takes advantage of the fact that a working range nearer the absolute maximum potential has an advantage over a working range nearer the absolute minimum. In order to move the working range toward the maximum in partial charge events, an artificial minimum level must be utilized rather than the absolute. The artificial minimum must be set between the absolute minimum and the absolute maximum. The artificial minimum is adjusted upward after a charge event if the absolute maximum potential is not reached (i.e., after an energetically disfavorable event). The adjustment upward may be a constant increment value. Conversely, the artificial minimum is adjusted downward toward the absolute minimum after a charge event if the maximum absolute potential is reached (i.e., after an energetically favorable event). The adjustment downward may also be a constant decrement value. The artificial minimum level is adjusted after a charge event as long as the energy state of the storage device has not reached or exceeded the absolute maximum.
The present invention accordingly allows one to achieve a balance between energy expended and replenished. That is, the net charge energy ought to be greater than or equal to the discharge energy of the storage device. A net loss of energy charge-to-discharge will tend to drive the working range of the device to the minimum potential.
A portion of the vehicle (system) kinetic energy is unavailable for charging the energy storage because of electrical and mechanical losses. To help achieve the balance between energy expended and replenished, the present invention attempts to limit the discharge energy to less than the charge energy. One approach is to discharge to vehicle speed A and charge from vehicle speed B where speed A is less than B. Another is to limit the discharge maximum power to less than the maximum charge power.
The present invention may also be applied to limit the artificial minimum to some maximum value so as to preserve a determined working range.
The present invention thus utilizes a strategy that optimizes the energy storage use over successive discharge/charge events. The average use is optimized not necessarily any one event.
Level determination and adjustment of the energy storage can be achieved, for instance, through either measuring energy potential or counting energy units in and out.
The process of limit adjustment will tend to preserve the optimal working range of an energy storage bank regardless of the capacity. Ideally and preferably, one may initialize the artificial minimum limit to the midpoint of the absolute minimum and maximum levels.
Without using the method of the present invention, the energy storage utilization will be driven toward the low power range of the storage device. This is especially the case with energy storage devices with more capacity than the kinetic energy of the vehicle or system.
Enhancement of the strategy is recommended to ensure all requests for power are satisfied with some hybrid power regardless of the energy level of the storage device. Also, in cases where a future charge event will be more favorable in terms of energy recapture, a lower artificial minimum can be set to allow more energy than normal to be expended at present. This may require a “fuzzy” or non-strict implementation of the artificial minimum. Fuzzy logic and/or expert systems can be utilized to predict future behavior based on past and present behavior. This may be especially successful with vehicles and systems with specific and consistent missions. In the case of vehicles, the use of GPS satellite data can provide valuable information to this end, such as overall route length, numbers and distance between acceleration and deceleration events, etc.
FIG. 1 is a schematic of an energy storage system describing the extent of the charge and discharge of the energy storage system as it proceeds through a series of energy discharge and energy recapture events. As may be appreciated from this Figure, an electric energy storage device (i.e., a capacitor; represented by a cylinder) proceeds through a series of energy discharge and energy recapture events while acceleration of the vehicle and regenerative braking occurs. FIG. 1 shows that, in instances where there is no control over the lower charge limit of the capacitor, the charge of the capacitor continues to drop over successive energy discharge and energy recapture events that are energetically disfavorable (i.e., where the output of energy upon acceleration exceeds the energy recaptured upon regenerative braking).
In contrast, FIG. 2 is a schematic of an energy storage system describing the extent of the charge and discharge of the energy storage system as it proceeds through a series of energy discharge and recapture events while being controlled by the method and system of one embodiment of the present invention. FIG. 2 shows that in accordance with the present invention the lower charge limit of the capacitor is controlled and adjusted. As shown in FIG. 2 , the charge of the capacitor drops in the case of an energy discharge and energy recapture event that is energetically disfavorable (i.e., where the output of energy upon acceleration exceeds the energy recaptured upon regenerative braking). In such cases, the controller of the present invention adjusts an artificial lower charge limit upward and above the absolute lowest charge level (i.e., the level of complete discharge). For instance, FIG. 2 shows a fully charged capacitor which proceeds through a full discharge event followed by a partially charging capture event. Thereafter, an artificial lower charge limit is set such that a subsequent discharge prevents complete discharging of the capacitor. During a subsequent discharge event, the capacitor is restricted from discharging below the artificial lower charge limit. Subsequently, and as this event is energetically unfavorable, the artificial lower charge limit is again raised from the previously set artificial lower charge limit. This process may be allowed to continue until an energy discharge and energy recapture event results in the complete recharging of the capacitor. In this instance, the artificial lower charge limit is lowered to a point lower than previously set, and above the absolute lowest charge level.
The apparatus and methods of the present invention may be produced using microprocessors and computer languages known and used in the art.
An example of an algorithm in pseudo code showing the adjustment of the artificial minimum charge level with the energy storage potential measured following a deceleration event is shown below. This may be used to bring about the control of the energy storage system of the present invention and may be understood by reference to the following logic for adjusting the minimum charge level with optional reference to system torque:
Pseudo Code for Adjusting Artificial Minimum Charge Level
Energy Storage Potential Measured Following a Deceleration Event
Simplest Form
The following algorithm is executed every iteration of the control loop. Ideally, the control loop is executed several times per second.
The variables, constants, and flags indicated in the algorithm are defined as follows:
VehicleSpeed, variable, measure of vehicle ground speed. PotentialLevel, variable, measure of energy storage potential (e.g. voltage). TargetLevel, variable, artificial minimum potential level to reach during discharge events, can be initialized to the midpoint between MAX_LEVEL and MIN_LEVEL. Prev_At_Speed, flag, indicates if vehicle has reached a pre-determined speed to trigger the level adjustment calculation after next deceleration event, initialized to false. MIN_LEVEL, constant, the lowest potential level allowed to be reached, oftentimes the absolute minimum potential of the storage device. MAX_LEVEL, constant, the highest potential level to be reached, oftentimes the absolute maximum potential of the storage device. MAX_TARGET_LEVEL, constant, the highest artificial minimum potential allowed, set to preserve a minimum working range. LEVEL_STEP, constant, the step value for target level adjustment, could also be a parameter resulting from a transfer function. LEVEL_ADJ_THRESHOLD, constant, minimum speed threshold before the level adjustment calculation can be triggered. AT_REST_THRESHOLD, constant, speed threshold below which the vehicle is considered to be at rest.
INITIALIZE:
.
.
.
Prev_At_Speed = FALSE
TargetLevel = ((MAX_LEVEL − MIN_LEVEL) / 2) + MIN_LEVEL
.
.
.
End INITIALIZE
CONTROL LOOP:
.
.
.
If VehicleSpeed > LEVEL_ADJ_THRESHOLD Then
Prev_At_Speed = TRUE
End If
If VehicleSpeed < AT_REST_THRESHOLD Then
If Prev_At_Speed = TRUE Then
If PotentialLevel >= MAX_LEVEL Then
TargetLevel = TargetLevel − LEVEL_STEP
If TargetLevel < MIN_LEVEL Then
TargetLevel = MIN_LEVEL
End If
Else
TargetLevel = TargetLevel + LEVEL_STEP
If TargetLevel > MAX_TARGET_LEVEL Then
TargetLevel = MAX_TARGET_LEVEL
End If
End If
Prev_At_Speed = FALSE
End If
End If
.
.
.
Go to CONTROL LOOP
An example of an algorithm in pseudo code showing the adjustment of the artificial minimum charge level with the energy storage potential measured prior to an acceleration event is shown below.
Pseudo Code for Adjusting Artificial Minimum Charge Level
Energy Storage Potential Measured Prior to an Acceleration Event
Simplest Form
The following algorithm is executed every iteration of the control loop. Ideally, the control loop is executed several times per second.
The variables, constants, and flags indicated in the algorithm are defined as follows:
VehicleSpeed, variable, measure of vehicle ground speed. PotentialLevel, variable, measure of energy storage potential (e.g. voltage). TargetLevel, variable, artificial minimum potential level to reach during discharge events, can be initialized to the midpoint between MAX_LEVEL and MIN_LEVEL. Prev_At_Speed, flag, indicates if vehicle has reached a pre-determined speed to trigger the level adjustment calculation after next deceleration event, initialized to false. MIN_LEVEL, constant, the lowest potential level allowed to be reached, oftentimes the absolute minimum potential of the storage device. MAX_LEVEL, constant, the highest potential level to be reached, oftentimes the absolute maximum potential of the storage device. MAX_TARGET_LEVEL, constant, the highest artificial minimum potential allowed, set to preserve a minimum working range. LEVEL_STEP, constant, the step value for target level adjustment, could also be a parameter resulting from a transfer function. LEVEL_ADJ_THRESHOLD, constant, minimum speed threshold before the level adjustment calculation can be triggered. AT_REST_THRESHOLD, constant, speed threshold below which the vehicle is considered to be at rest. Torque Request, variable, indicator of drive torque requested of the hybrid system. ZERO_TORQUE, constant, torque threshold below which the hybrid drive applies no driving torque.
INITIALIZE:
.
.
.
Prev_At_Speed = FALSE
TargetLevel = ((MAX_LEVEL − MIN_LEVEL) / 2) + MIN_LEVEL
.
.
.
End INITIALIZE
CONTROL LOOP:
.
.
.
If VehicleSpeed > LEVEL_ADJ_THRESHOLD Then
Prev_At_Speed = TRUE
End If
If VehicleSpeed < AT_REST_THRESHOLD Then
If Prev_At_Speed = TRUE Then
If TorqueRequest > ZERO_TORQUE Then
If PotentialLevel >= MAX_LEVEL Then
TargetLevel = TargetLevel − LEVEL_STEP
If TargetLevel < MIN_LEVEL Then
TargetLevel = MIN_LEVEL
End If
Else
TargetLevel = TargetLevel + LEVEL_STEP
If TargetLevel > MAX_TARGET_LEVEL Then
TargetLevel = MAX_TARGET_LEVEL
End If
End If
Prev_At_Speed = FALSE
End If
End If
End If
.
.
.
Go to CONTROL LOOP
As may be appreciated from the foregoing, other algorithms and programming may be used to bring about the results described herein, such as is illustrated in FIGS. 1 and 2 .
FIG. 3 shows a schematic of a hybrid electric vehicle in accordance with one embodiment of the present invention. FIG. 3 shows Internal combustion engine 1 (e.g., Cummins ISB170 Diesel), Multi-speed automatic transmission 2 , (e.g., Allison T2000 series), Ultracapacitor energy storage unit 3 , (e.g., Maxwell BCAP series cells, 400 Volt maximum), Induction motor 4 , (e.g., liquid cooled NEMA 215 frame, EVI Part 205-0000), Induction motor inverter/controller 5 , (e.g., IGBT-based EMS FluxDrive 7 ), Hybrid supervisory controller with CAN interface 6 (e.g., 8-bit microcontroller based, PIC18F248), Commercial truck chassis 7 , (e.g., 15,000 pound GVWR, Workhorse Custom Chassis) and Vehicle control network 8 (e.g., Controller Area Network (CAN), SAE J1939 protocol).
FIG. 4 is a schematic representation of the control nodes that may be used in accordance with one embodiment of the present invention.
In accordance with the preferred embodiment, a parallel electric hybrid is provided which uses ultracapacitors as the energy storage device. As electric power is transferred in and out of the bank of ultracapacitors through successive discharge and charge events, the present invention works to maximize the usefulness of the ultracapacitor bank by regulating the minimum discharge set point.
As indicated above, the major system components of the hybrid vehicle are linked together via an electronic data bus that allows for control and state messages to be passed freely between connected nodes (as shown schematically in FIG. 4 ). This embodiment uses a standard high-speed data network commonly used in commercial medium and heavy duty truck and bus systems. The network is based on the Controller Area Network (CAN) topology commercially available from Robert Bosch and preferably utilizes the Society of Automotive Engineers (SAE) J1939 software protocol which dictates a message bit rate of 250K bits per second and message addressing conventions.
Conventional medium and heavy duty vehicles typically link the engine, transmission, and brake systems on the network for control and data sharing. Tens of standard messages are broadcast by these nodes several times per second. The hybrid components of this embodiment also use this electronic network. Nodes key to the present invention that link the motor drive and the hybrid supervisory controller to the network are added. Other hybrid component nodes which supplement the supervisory controller are also added. These include a brake pedal module, a dashboard/display module, an ultracapacitor module, and a motor/gearbox module.
The supervisory controller of this embodiment is an electronic controller that accepts and transmits data messages from the network and executes algorithms to elicit behavior from the motor drive, engine, and transmission of the vehicle, although equivalent controllers may be used. This behavior creates the expected hybrid performance, such as supplanting engine torque with motor torque under acceleration and supplanting friction braking with reverse motor torque under deceleration. Also, the present invention allows an optimizing of the use of the hybrid energy storage unit.
The controller preferably is based on an 8-bit microcontroller from Microchip, the PIC18F248. The algorithms of the present invention are translated from a high-level programming language, such as C or Basic, to machine code that can be written to the microcontrollers FLASH program memory. For instance, the algorithms are coded into Basic, compiled into Assembly language, then assembled and linked into machine code for the particular PIC device. The machine code, typically in the form of a string of hexadecimal numbers, is then programmed into the FLASH memory of the target microcontroller using a hardware programming device. Once programmed, the microcontroller begins execution of the algorithms immediately after power is applied.
Vehicle speed and potential level of the energy storage device, in the case of ultracapacitors, Voltage. The state of charge (or energy state) of the ultracapacitor follows directly the following relation,
energy=½*capacity*potential 2 ,
where energy is in Joules, capacity is in Farads, and potential is in Volts.
Assuming that the capacity of the device does not change with operation, it can be seen that the energy level of the device is directly proportional to the square of the potential, or of voltage. Therefore, a simple measure of the ultracapacitor voltage can allow one to derive the energy level rather easily and is the basis of the algorithm of the present invention. The capacity of the ultracapacitor or similar energy storage device can be obtained experimentally or by consulting the manufacturer's specifications.
Aside from the 10 Hz control loop, the supervisory controller is also programmed to watch the network traffic on the CAN bus for messages of interest, particularly the ones cited above. When a message of interest is detected, the active process is interrupted and the message is decoded and the data elements stored. This ensures that state parameters used in the algorithms, such as vehicle speed and ultracapacitor voltage, are current.
During each pass of the control loop the state parameters and local variables are evaluated and the algorithms executed. Simple example algorithms of the present invention are provided in pseudo code. The algorithm of the present invention can be made perhaps more effective by incorporating other sophisticated techniques. These techniques may include predictive elements, the use of energy level instead of potential level for adjustment strategy, and others as indicated elsewhere.
Many other changes and modifications may be made to the present invention without departing from the spirit thereof. The scope of these and other changes will become apparent from the appended claims.
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The present invention is a method and apparatus by which power is controlled in a hybrid electric vehicle such that high levels of performance and efficiency are realized. The present invention includes a method and apparatus developed to optimize the use of energy in a hybrid vehicle application from the hybrid energy storage device. The method and apparatus of the present invention is particularly useful with energy storage devices there the energy state, such as the state of charge, is readily determined by an easily measured attribute. Ultracapacitors and hydraulic storage cylinders are examples of the types of energy storage devices to which the present invention may be applied.
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TECHNICAL FIELD
The present invention relates generally to seat restraint systems for vehicles and, more particularly, to a tension sensing switch assembly for a seat restraint system in a vehicle.
BACKGROUND OF THE INVENTION
It is known to provide a seat restraint system such as a seat belt in a vehicle to restrain an occupant in a seat of the vehicle. In some vehicles, the seat restraint system may be a lap belt, a shoulder belt or both. Typically, the lap belt and shoulder belt are connected together at one end. The seat restraint system includes a latch plate at the connected end. The seat restraint system also includes a buckle connected at one end by webbing or the like to vehicle structure. The buckle receives the latch plate to be buckled together. When the buckle and latch plate are buckled together, the seat restraint system restrains movement of the occupant to help protect the occupant during a collision.
Smart inflatable restraint systems need to know what is occupying a seat of the vehicle. Decisions on deployment on inflatable restraint depend on information supplied by sensors in the seat in determining weight of an object in the seat. When a child seat is placed in the seat and cinched down, the sensors may read a large mass instead of a child seat. With this condition, there will be high tension in the seat restraint system. Comfort studies have shown that no human occupant would wear their seat restraint that tight. With this information on seat restraint tension, the inflatable restraint system can decide on deployment of the inflatable restraint.
Although the above seat restraint system has worked, it is desirable to provide a switch for sensing tension in a seat restraint system of a vehicle. It is also desirable to provide a switch for a seat restraint system in a vehicle that allows a control module to determine the difference between either a child seat or a small occupant. It is further desirable to provide a switch for a seat restraint system in a vehicle that provides information used in determining inflatable restraint deployment levels.
SUMMARY OF THE INVENTION
It is, therefore, one object of the present invention to provide a switch assembly for sensing tension in a seat restraint system of a vehicle.
It is another object of the present invention to provide a dual resistance switch for sensing tension in a seat restraint system of a vehicle.
To achieve the foregoing objects, the present invention is a tension sensing switch assembly for a seat restraint system in a vehicle includes a housing for operative connection to the seat restraint system and a spring at least partially disposed in the housing for operatively cooperating with vehicle structure. The tension sensing switch assembly also includes a switch disposed in the housing and cooperable with the spring to indicate a first tension level and a second tension level in the seat restraint system when the spring is deflected.
One advantage of the present invention is that a tension sensing switch assembly is provided for a seat restraint system in a vehicle. Another advantage of the present invention is that the tension sensing switch assembly senses tension in the seat restraint system to help identify what is occupying the seat, either a child, child seat or low mass adult. Yet another advantage of the present invention is that the tension sensing switch assembly has a dual resistance switch that is diagnosable. Still another advantage of the present invention is that the tension sensing switch assembly provides information useful in determining deployment of an inflatable restraint system.
Other objects, features and advantages of the present invention will be readily appreciated, as the same becomes better understood after reading the subsequent description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a tension sensing switch assembly, according to the present invention, illustrated in operational relationship with a seat restraint system of a vehicle.
FIG. 2 is a fragmentary plan view of the tension sensing switch assembly of FIG. 1 illustrating a low tension condition.
FIG. 3 is a view similar to FIG. 2 illustrating the tension sensing switch assembly in a high tension condition.
FIG. 4 is a schematic view of a circuit for the tension sensing switch assembly of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and in particular FIGS. 1 and 2, one embodiment of a tension sensing switch assembly 10 , according to the present invention, is shown for a seat restraint system, generally indicated at 12 , in a vehicle (partially shown), generally indicated at 14 . The vehicle 14 includes a vehicle body 16 and a seat 18 mounted by suitable means to vehicle structure 20 such as a floorpan in an occupant compartment 22 of the vehicle body 16 . In this embodiment, the seat 18 is a front seat of the vehicle 14 . It should be appreciated that the seat 18 could be a rear, second row or third row seat for the vehicle 14 .
Referring to FIGS. 1 and 2, the vehicle 14 includes the seat restraint system 12 for restraining an occupant (not shown) in the seat 18 . The seat restraint system 12 includes a latch tongue or plate (not shown) connected to an end of either one of a lap belt, shoulder belt, or both (not shown) which have another end connected to a retractor (not shown). The seat restraint system 12 also includes a buckle assembly 24 and the tension sensing switch assembly 10 interconnected by suitable means such as belt webbing 26 . The tension sensing switch assembly 10 is connected to the vehicle structure 20 in a manner to be described. It should be appreciated that the latch plate has an aperture extending therethrough and is engageable and disengageable with the buckle assembly 24 . It should be appreciated that, except for the tension sensing switch assembly 10 , the seat restraint system 12 and vehicle 14 are conventional and known in the art.
Referring to FIGS. 1 through 3, the tension sensing switch assembly 10 , according to the present invention, includes an anchor plate 28 connected to vehicle structure by suitable means such as an anchor bolt 30 . The anchor bolt 30 has a head portion 32 extending radially and a shaft portion 34 extending axially from the head portion 32 . The shaft portion 34 is generally cylindrical in shape and the head portion 32 is generally circular in shape. The head portion 32 has a diameter greater than a diameter of the shaft portion 34 . The shaft portion 34 extends through an aperture 44 to be described in the anchor plate 28 and the vehicle structure 20 and is secured in place by a nut (not shown). It should be appreciated that the anchor bolt 30 is conventional and known in the art.
The anchor plate 28 has a base portion 36 and a tongue portion 38 extending axially and upwardly from the base portion 36 . The base portion 36 has a first portion 40 that is generally rectangular in shape. The base portion 36 also has a second portion 42 extending axially from the base portion 36 . The second portion 42 has a width less than the first portion 40 . The second portion 42 has an elongated aperture or slot 44 extending therethrough and axially to receive the anchor bolt 30 . It should be appreciated that the second portion 42 of the base portion 36 is disposed between the head portion 32 of the anchor bolt 30 and the vehicle structure 20 . It should also be appreciated that the anchor plate 28 is movable longitudinally relative to the anchor bolt 30 .
The tongue portion 38 is generally rectangular in shape and has a width the same as the second portion 42 of the base portion 36 . The tongue portion 38 includes an aperture 46 extending therethrough. The aperture 46 is generally rectangular in shape and receives one end of the belt webbing 26 . The base portion 36 and tongue portion 38 are made of a metal material and formed as a monolithic structure being integral, unitary and formed as one-piece.
The tension sensing switch assembly 10 also includes a housing 48 disposed about and enclosing the first portion 40 of the base portion 36 of the anchor plate 28 . The housing 48 has a cavity 49 with an aperture 50 at a forward end for a function to be described. The housing 48 has a pair of posts 52 disposed in the cavity 49 and being laterally spaced and extending upwardly adjacent the aperture 50 . The housing 48 is generally rectangular in shape and made of a rigid material such as plastic. It should be appreciated that only one half of the housing 48 is illustrated in FIGS. 2 and 3.
The tension sensing switch assembly 10 includes a spring 54 at least partially disposed in the cavity 49 of the housing 48 . The spring 52 is of a leaf type having a first end 56 disposed about one of the posts 52 in the housing 48 and a second end 58 disposed about the other post 52 in the housing 48 . The spring 54 has a bowed or arcuate shape to cooperate with the shaft portion 34 of the anchor bolt 30 . The spring 54 is made of a metal material. The spring 52 is tuned to a predetermined force for comfort. The spring 54 may also be of a coil spring type. It should be appreciated that the anchor bolt 30 deflects the spring 54 when the anchor plate 28 is moved relative to the anchor bolt 30 .
Referring to FIGS. 2 through 4, the tension sensing switch assembly 10 includes an electrical circuit, generally indicated at 60 , for diagnosing usage of the seat restraint system 12 . The electrical circuit 60 includes a switch 62 for cooperating with the spring 54 . The switch 62 is diagnosable and has two positions. Preferably, the switch 62 is of a micro type that is actuated by an arm or bail 64 pivotally connected to the switch 62 . The switch 62 may also be of another suitable type such as a reed or Hall effect type. The bail 64 will move or pivot when the spring 54 engages the bail 64 . The spring 54 moves the bail 64 from an open or first position with the switch 62 illustrated in FIG. 2 to a closed or second position illustrated in FIG. 3 . It should be appreciated that the position of the bail 64 relative to the switch 62 changes the state of the switch 62 , giving a different output current from the switch 46 . It should also be appreciated that the bail 64 is preloaded by a spring (not shown) to return the bail 64 to the first position.
The circuit 60 also includes a first resistor 66 interconnecting one end of the switch 62 and ground 68 . The first resistor 66 has a predetermined value such as one hundred ohms (100 Ω). The circuit 60 includes a second resistor 70 connected in parallel with the switch 46 with one end interconnecting the switch 62 and the first resistor 66 and another end connected to a source of power 72 such as a controller (not shown) of the vehicle 14 . The second resistor 70 has a predetermined value such as three hundred ohms (300 Ω). The circuit 60 is mounted on a circuit board (not shown) connected to the housing 48 and is potted and connected by electrical leads or wires to the source of power 72 and ground 68 .
In operation of the tension sensing switch assembly 10 , the occupant buckles the seat restraint system 12 and the tension in the belt webbing 26 is lower than a predetermined load required to deflect the spring 54 as illustrated in FIG. 2 . In this state, the tension sensing switch assembly 10 will send an open signal to the controller. Current from the source of power 72 flows through the second resistor 70 and first resistor 66 to ground 68 . The flow of current through the both resistors 66 and 70 causes the controller to determine that a normal or large mass adult is present in the seat 18 . It should be appreciated that the anchor plate 28 of the tension sensing switch assembly 10 is spring loaded to an initial position by the spring 54 .
When a child seat (not shown) is placed in the seat 18 and the seat restraint system 12 is buckled, the seat belt webbing 26 is cinched to pull the child set tightly in to the seat 18 . The tension in the seat belt webbing 26 is above the predetermined level to deflect the spring 54 as illustrated in FIG. 3 . In this state, the deflection of the spring 54 causes the switch 62 to change states, sending a closed contact signal to the controller. Current from the source of power 72 flows through the switch 62 and first resistor 66 to ground 68 . The flow of current through only one resistor 66 causes the controller to determine that a child seat is present in the seat 18 . Also, if the controller receives no signal from the switch 62 , the controller determines that there is an unplugged wiring connector (not shown) to the seat restraint system 12 . Further, if the controller receives a signal from the switch 62 approximately equal to the current from the source of power 72 , the controller determines that there is a shorted wiring connector to the seat restraint system 12 . It should be appreciated that the when the belt webbing 26 is tensioned past a predetermined force, the spring 54 will deflect or travel approximately three millimeters (3.0 mm), causing the switch 62 to change states. It should be appreciated that an audible tone or visual indication may be provided when the tension in the belt webbing 26 is increased above the predetermined level.
The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.
Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.
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A tension sensing switch assembly for a seat restraint system in a vehicle includes a housing for operative connection to the seat restraint system and a spring at least partially disposed in the housing for operatively cooperating with vehicle structure. The tension sensing switch assembly also includes a switch disposed in the housing and cooperable with the spring to indicate a first tension level and a second tension level in the seat restraint system when the spring is deflected.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent application Ser. No. 61/509,277 filed Jul. 19, 2011, the entire contents of which is herein incorporated by reference.
FIELD OF THE INVENTION
[0002] The present application is related to apparatuses and processes for producing and harvesting microalgae.
BACKGROUND OF THE INVENTION
[0003] Depleting cheap fossil fuel reserves and a pressing need for greenhouse gas (GHG) emission reduction are two major technico-economic challenges. Thus, it is quite urgent to develop cost effective, clean and renewable sources for both energy and chemical needs. Microalgae is actively investigated as a long term solution to cover these needs. Microalgae has a potential of producing up to 4,000 Gallons of oil per acre per year. This production rate is more than an order of magnitude higher than any other biofuel source. However currently used production and harvesting processes of microalgae are energy intensive and relatively costly. Except for a few high value nutrients, proteins and other byproducts, microalgae based biofuels are not commercially viable. Furthermore, current energy intensive harvesting processes give rise to significant CO 2 emissions.
[0004] There are five important processing steps required to obtain biofuels and/or chemicals from microalgae. Step #1 involves cultivating microalgae to produce more microalgae. Following the cultivation step, microalgae is collected and dewatered in Step #2 leading to concentrated dilute microalgal suspensions having TSS (total solid suspensions) content in a range from 0.5 to 5%. More extensive dewatering process combining one or more techniques that include centrifugation, flocculation, filtration and screening, gravity sedimentation, flotation and electrophoresis increases the TSS content up to around 10-20% TSS (Step #3). In Step #4, a drying process gives rise to a TSS of at least 25%. In the last step (Step #5), extraction processes are undertaken to produce the final product. In some cases, product extraction may be undertaken before the drying step. For example, in the case of anaerobic digestion primary dewatering is sufficient.
[0005] Following the cultivation step using a photobioreactor, the yield is often in the range of a maximum of about 1 kg dry weight/day/m 3 . The average TSS content is about 0.05% (Step #1). The large amount of water comprises extracellular and intracellular water. Depending on the requirements for drying (Step #4) and extraction (Step #5) and the targeted list of final products and byproducts, intracellular water removal may take place at different stages.
[0006] Different processing technologies are used for transforming the slurry to a sludge/cake and then to a dry state. Depending on the dewatering process, these industrial processes may also give rise to low specific production yield. The yield of these dewatering processes should be high while using minimum amount of energy.
[0007] A drying process that allows the completion of the harvesting process could increase the TSS content to about 75%. Dehydration faces two challenges related to algae degradation and loss of valuable chemicals and high energy cost. In the case of extraction, the following processes are often used: mechanical crushing (expeller press), solvent (hexane, benzene) extraction, supercritical CO 2 , enzymatic hydrolysis, microwave, cavitation and cellular decompression.
[0008] Three different algae cultivation methods are used including raceway pond, tubular photobioreactor and flat plate photobioreactor. Raceway pond has the lowest capital cost with the lowest energy input. However raceway pond uses significant land area and water with poor biomass productivity. Furthermore, raceway pond systems are limited to a few strains of algae with less control over the cultivation conditions. A photobioreactor can be generally described as an enclosed, illuminated culture vessel designed for controlled biomass production of phototrophic liquid cell suspension cultures. Tubular photobioreactors have been developed to increase biomass productivity by providing a large specific illumination surface area and more control of cultivation conditions. Capital cost of tubular reactors is relatively higher than raceway pond. They also present several challenges related to fouling, presence of oxygen and CO 2 , and gradients of pH values. They require large land area, although less than the raceway pond. In the third method, flat plate photobioreactors provide the highest biomass productivity, although illumination conditions are less than optimal. Flat plate photobioreactors are cheaper to produce, but they are difficult to scale-up with significant temperature control challenges. Per unit mass of produced algae, flat plate photobioreactors are cost effective.
[0009] Cultivation and dewatering represent two significant challenges for implementing commercial processes. These steps are critical for implementing an algae-based manufacturing of chemicals (nutrients, proteins) and biofuel (biodiesel) products. Unless the financial and energy costs of these two steps are significantly reduced, the commercial viability of biodiesel-based microalgae is questionable. However, high value byproducts such as nutrients and protein obtained from microalage are currently commercially viable.
[0010] The majority of dewatering techniques are based on water removal from the algae suspension. Electrochemical processes including electrodeposition (ED), electrocoagulation (EC), electroflotation (EF) and electrooxidation (EO) could be used for algae removal. Reducing the energy cost in the algae dewatering and drying processes while maintaining high yield output are commercially important. For example, electroflotation presents several attributes for large scale algae removal. Indeed, large scale algae removal from waste using electroflotation has been demonstrated. They do not require additional chemical flocculants or a sacrificial electrode and give rise to high yield (90% or more). Adding chemicals makes the downstream processes even more complicated and expensive. Electrodeposition and electroflotation face other specific challenges related mostly to additional capital cost.
[0011] Combining two or more of the processing steps discussed above into a single step would not only reduce capital cost but would also reduce cost of operation and maintenance (O&M). In particular, combining cultivation and dewatering using a single apparatus and/or process could allow high production yield with reduced production cost.
[0012] There remains a need for a photobioreactor design and process that meets one or more of the aforementioned challenges.
SUMMARY OF THE INVENTION
[0013] In one aspect of the present invention, there is provided a photobioreactor for producing and harvesting microalgae, the photobioreactor comprising: a vessel for cultivating microalgae, the vessel having at least one wall and an interior, at least a portion of the at least one wall being transparent to permit light of a frequency necessary to promote microalgae growth to enter into the interior of the vessel, at least part of the transparent portion of the at least one wall comprising a layer of transparent conductive oxide for use as an electrode, the transparent conducting oxide being transparent to light of the frequency necessary to promote microalgae growth and opaque to light of an infrared frequency range; and, a counter-electrode electrically connected to the layer of transparent conductive oxide for providing a potential difference across at least a portion of the interior of the vessel between the layer of transparent conductive oxide and the counter-electrode.
[0014] In another aspect of the present invention, there is provided a process for producing and harvesting microalgae in a single apparatus, the process comprising: cultivating microalgae on a cell culture medium in a vessel of a photobioreactor, the vessel having at least one wall and an interior, at least a portion of the at least one wall being transparent to permit light of a frequency necessary to promote microalgae growth to enter into the interior of the vessel, at least part of the transparent portion of the at least one wall comprising a layer of transparent conductive oxide for use as an electrode, the transparent conducting oxide being transparent to light of the frequency necessary to promote microalgae growth and opaque to light of an infrared frequency range; and, dewatering the microalgae electrochemically by applying a potential difference across at least a portion of the interior of the vessel between the layer of transparent conductive oxide and a counter-electrode electrically connected to the layer of transparent conductive oxide.
[0015] Microalgae, or microphytes, are microscopic, photosynthetic algae that may be found in freshwater or marine systems. They are unicellular, existing individually or in chains or groups. Depending on species, their sizes can range from about 0.1 micrometer to a few hundreds of micrometers. Microalgae are important industrially since they are capable of producing unique bio-products, for example, carotenoids, antioxidants, fatty acids (e.g. omega-3-fatty acids), enzymes, polymers, peptides, fuels, toxins and sterols. Any suitable species of algae may be cultivated in the photobioreactor, the choice of which depends on the type of bio-product that is desired to be produced. Chlorella, Dunaliella and Nannochloropsis are few examples of microalgae that could be used in the present photobioreactors. Cultivation occurs in a cell culture medium comprising necessary nutrients and factors for algae growth. Such nutrients and factors are well known in the art and depend on the species of algae being cultivated.
[0016] Any suitable basic design for the photobioreactor may be used, for example, tubular or flat plate photobioreactors. Tubular photobioreactors generally comprise a cylindrical vessel having a curved outer wall at least a portion of which is transparent. Flat plate photobioreactors generally comprise at least two opposed outer walls, at least part of at least one of which is transparent. Whatever the basic design, the photobioreactor comprises a vessel within which the microalgae is cultivated. The vessel comprises walls for containing the microalgae and the cell culture medium. Since microalgae are photosynthetic organisms, they require light in order to grow and reproduce. The light is generally of a frequency in the visible region of the electromagnetic spectrum. In order to permit light to enter the vessel, at least a portion of at least one wall of the vessel is transparent. Transparency may be attained by constructing the transparent portion of the vessel from a transparent material, for example, glass, plastic, fiber glass or mixtures thereof. More light can be permitted to enter the vessel by increasing the surface area of the transparent portion in relation to the total surface area of the vessel. If desired, the entire vessel may be constructed from transparent material. The wall of the vessel for which at least a portion is transparent is preferably an outer wall of the vessel.
[0017] At least part of the transparent portion of the at least one wall comprises a layer of transparent conductive oxide (TCO) for use as an electrode. In photobioreactor designs where the entire vessel is transparent, it is possible for the TCO layer to cover the entire photobioreactor, although the exact surface area of the TCO layer depends on design considerations. The TCO layer is preferably on the inside of the vessel surface.
[0018] In thin layers, transparent conducting oxides are optically transparent to visible wavelengths (380 nm to 750 nm) and are electrically conductive. They have been typically used in electronic applications, for example microelectronics, photonics (e.g. solar cells) and architecture windows. Some examples of TCOs include indium doped tin oxide (ITO), fluorine doped tin oxide (FTO), antimony doped tin oxide (ATO), zinc doped tin oxide (ZTO), aluminum doped zinc oxide (AZO) or mixtures thereof. TCO layers typically have a thickness in a range of from about 0.01 μm to about 100 μm. The preferred thickness is in a range of from about 0.1 μm to about 10 μm.
[0019] About 45% of solar radiation, which is typically used as the light source for photobioreactors, comprises infrared light. Infrared light does not contribute to the photosynthetic process in microalgae, however, infrared light does contribute to increased temperature and radial thermal gradient in the photobioreactor. Such thermal heating under solar load makes temperature control in the vessel difficult leading to over-heating and algae death, thus reducing production yield. While transparent conducting oxides are optically transparent to visible wavelengths, they are opaque to infrared wavelengths. Thus, the TCO layer blocks at least a portion of the infrared region of solar radiation mitigating against thermal heating in the photobioreactor while transmitting the visible portion to be used by the microalgae in the photosynthetic process. This is a major advantage in photobioreactor design.
[0020] The transparent conducting oxide (TCO) layer also functions as an electrode. When coupled with a counter-electrode, a potential difference can be generated across at least a portion of the interior of the vessel between the transparent conductive oxide layer and the counter-electrode. This permits application of electrochemical processes to harvest the microalgae growing in the vessel. The counter-electrode may be a layer on another wall of the vessel, or it may be an electrode placed somewhere in the interior of the vessel. The counter-electrode may comprise any suitable electrically conductive material, for example a metal (e.g. aluminum, stainless steel, etc.), a conductive carbon, a transparent conducting oxide (TCO) or a mixture thereof. If the counter-electrode comprises a TCO, the TCO of the counter-electrode may be the same or different as the TCO in TCO layer. If the counter-electrode is metal-based and is to be placed within the vessel where it is in contact with the microalgae and other contents of the vessel, it may be advantageous to coat the counter-electrode with an inert coating, for example a fluorine-type coating (e.g. polytetrafluoroethylene (PTFE)). For greater efficiency, the counter-electrode preferably has a length that spans the interior of the vessel. The counter-electrode may be fixed or moveable (e.g. rotatable). The potential difference can be generated by applying a voltage between the transparent conductive oxide layer and the counter-electrode. The voltage may be generated by any suitable electrical power source. The two electrodes may be placed in any suitable orientation in the vessel, for example, vertically, horizontally or at some other angle with respect to the direction of earth's gravitational field. The TCO electrode and the counter-electrode may have the same or different orientations with respect to each other. In one embodiment, the counter-electrode is oriented perpendicularly to the orientation of the layer of transparent conductive oxide.
[0021] Any number of different electrochemical processes may be applied through the TCO electrode and counter-electrode to facilitate growth, dewatering and/or separation of the microalgae. Electrochemical processes include electrophoretic and/or electrolytic processes, for example water electrolysis, electrodeposition (ED), electrocoagulation (EC), electroflotation (EF) and electrooxidation (EO).
[0022] In an embodiment of an electrophoretic process, application of low voltage and low current density across the two electrodes after a complete photosynthesis cycle permits collection and dewatering of the microalgae through electrodeposition. Typically, a voltage in a range of from about 1 V to about 100 V is applied, depending on the algae concentration, pH and the distance between the two electrodes. Negatively charged microalgal cells migrate to the positively polarized electrode (anode) where they form aggregates (flocculates) of microalgae cells at the surface of the anode. The aggregated cells may then be conveniently collected with or without removing the electrode from the vessel. The collected aggregates have much higher solids content than the microalgae during cultivation.
[0023] In an embodiment of an electrolytic process, application of a high enough voltage to electrolyze water into hydrogen and oxygen permits the generation of gases that induce turbulence that increases bulk photosynthesis efficiency and algae yield. Oxygen generated at the anode where microalgae flocculation is occurring helps float the microalgae flocculates to the surface of the medium in the vessel via an electroflotation process. Flocculated and floated microalgae cells can then be more conveniently harvested and have a much higher solids content than the microalgae during cultivation. Flocculated and floated microalgae cells may be collected with or without removing the electrode from the vessel. Orienting the anode in a horizontal manner promotes electroflotation.
[0024] Thus, the transparent conducting oxide layer can advantageously serve three purposes for cultivating and harvesting microalgae in a single apparatus. It reduces infrared radiation absorption in the photobioreactor facilitating temperature control under high solar radiation load. It permits utilization of electrophoretic techniques to perform dewatering. And, it permits generation of water electrolysis gas to increase bulk photosynthesis efficiency and algae yield and to perform further dewatering by fostering flocculation and floatation of the microalgae.
[0025] The photobioreactor may comprise other standard accessories and connections to allow algae growth during cultivation. Such accessories include, for example, means to introduce carbon dioxide, means to introduce water, means to introduce nutrients, means for mixing and means for gas removal (e.g. hydrogen and oxygen removal). Further, membranes may be included between the TCO electrode and counter-electrode to facilitate electrochemical processes. Further, spatial orientation of the photobioreactor may be adjusted to improve mixing of bulk microalgae in the vessel and/or to improve spatio-temporal light distribution in the vessel.
[0026] After cultivation and dewatering, microalgae are collected from the anode using any suitable means, for example, mechanically (e.g. scraping) or by dissolving the microalgae in a suitable solvent. Collection may be performed by first removing the anode from the photobioreactor (a batch process) or by collecting the microalgae from the anode without removing the anode from the photobioreactor (a continuous process). The collected microalgae is further dried and then the desired bio-product is recovered. Drying may be accomplished by any suitable means, for example, centrifugation, pressing and filtering. The ultimate drying process includes thermal sources (electrical and/or solar), which could lead to a TSS content in the range of about 75%. Bio-product recovery from the dried microalgae may be accomplished by any suitable means, for example, solvent extraction, anaerobic digestion (a wet process) and pyrolysis (a dry process). Liquids left behind during dewatering and drying may be reused or treated to remove valuable components including nutrients, dissolved bio-products and the like.
[0027] Photobioreactors and processes of the present invention using a transparent conducting oxide layer and combining growth and dewatering steps advantageously leads to improved algae yield, reduced capital cost, reduced operating costs and use of fewer added chemicals for flocculation. The present photobioreactors and processes are efficient for producing bio-products using microalgae and solar energy, and also advantageously sequester carbon dioxide.
[0028] Further features of the invention will be described or will become apparent in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order that the invention may be more clearly understood, embodiments thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which:
[0030] FIG. 1 depicts a simplified microalgae value chain showing steps in a process for obtaining bio-product from microalgae cultivation;
[0031] FIG. 2A depicts a schematic representation in plan view of a simplified tubular photobioreactor in accordance with the present invention having a transparent conductive oxide (TCO) layer coated on an outside wall of the photobioreactor, where algae aggregates are collected at the surface of the culture medium;
[0032] FIG. 2B depicts a schematic representation in top view of the tubular photobioreactor of FIG. 2A ;
[0033] FIG. 3 depicts a schematic representation in side view of a simplified flat plate photobioreactor in accordance with the present invention having a first transparent conductive oxide (TCO) layer coated on an outside wall of a first plate and a second different transparent conductive oxide (TCO) layer coated on an inside wall of a second plate;
[0034] FIG. 4A depicts a graph of temperature (° C.) vs. time of the day (hr) for a photobioreactor constructed from just glass (Glass-PBR) compared to a photobioreactor of the present invention constructed from TCO-coated glass (TCO-PBR); and,
[0035] FIG. 4B depicts a graph of algae concentration (a.u.) vs. time (hrs) for algae growth in a photobioreactor constructed from just glass (Glass-PBR) compared to a photobioreactor of the present invention constructed from TCO-coated glass (TCO-PBR).
DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] A simplified microalgae value chain showing steps in a process for obtaining bio-product from microalgae cultivation is depicted in FIG. 1 . In Step #1, microalgae is cultivated by growing it on a cell culture medium in a photobioreactor. Typically, the total solids content (TSS) of the algal effluent created during cultivation is on the order of about 0.05%. After cultivation to produce quantities of microalgae, the microalgae must be dewatered and harvested. Dewatering typically takes place in a primary dewatering step (Step #2) to produce an algal slurry having a TSS in a range of from about 0.5-5% followed by a secondary dewatering step (Step #3) producing an algal sludge/cake having a TSS in a range of from about 10-20%. Primary and secondary dewatering using electrochemical processes is primarily concerned with removing extracellular water. In the present process, cultivation, primary dewatering and secondary dewatering may all be accomplished in the same apparatus, i.e. the photobioreactor, and the algae harvested only at the end of the secondary dewatering step. The process can therefore be more efficient and cost effective.
[0037] After harvesting the algae from the secondary dewatering step, the algae is further dried in Step #4 to provide dried algae having a TSS of about 25% or more. The drying step may further focus on removal of intracellular water. Dried algae can then be processed to recover desired bio-products.
Example 1
Tubular Photobioreactor
[0038] Referring to FIG. 2 , a tubular photobioreactor comprises cylindrical vessel 1 having outer wall 2 made of a transparent plastic that permits solar energy to enter the interior of vessel 1 where the microalgae is being cultivated. Outer wall 2 has a curved inside and outside surface and the inside surface is coated with transparent conducting oxide (TCO) layer 3 comprising fluorine doped tin oxide (FTO). The TCO layer blocks infrared red light from entering the vessel while transmitting visible light. TCO layer 3 also acts as an electrode in an electric circuit further comprising rod-like counter-electrode 5 made from PTFE-coated aluminum and power generator 9 for applying a voltage across the electrodes. Applying low voltage and current across the electrodes after the microalgae production cycle is complete polarizes the electrodes, with TCO layer 3 being a cathode (negative) and counter-electrode 5 being an anode (positive). Since microalgae are slightly negatively charged, the microalgae produced during cultivation are repelled from negatively charged TCO layer 3 on the outside wall of cylindrical vessel 1 and attracted to positively charged anode 5 suspended in the algae culture medium along the full length of and in the center of cylindrical vessel 1 . On applying a voltage and current sufficient to electrolyze water, aggregates 7 of microalgal cells are carried to the surface of the culture medium by hydrogen and oxygen gas bubbles formed during water electrolysis. For simplicity, standard photobioreactor accessories and connections are not shown in FIG. 2 .
Example 2
Flat Plate Photobioreactor
[0039] Referring to FIG. 3 , a flat plate photobioreactor comprises vessel 11 having opposed first outer wall 14 and second outer wall 16 both made of a transparent plastic that permits solar energy to enter the interior of vessel 11 where the microalgae is being cultivated. The inside surfaces of outer walls 14 and 16 are coated with transparent conducting oxide (TCO) layers 13 and 15 , respectively, each TCO layer comprising fluorine doped tin oxide (FTO). The TCO layers block infrared red light from entering the vessel while transmitting visible light. TCO layers 13 and 15 also act as electrodes in an electric circuit further comprising power generator 19 for applying a voltage across the electrodes. On applying a voltage and current sufficient to electrolyze water, aggregates 17 of microalgal cells are carried to the surface of the culture medium by hydrogen and oxygen gas bubbles formed during water electrolysis. For simplicity, standard photobioreactor accessories and connections are not shown in FIG. 3 .
Example 3
Collecting Microalgae Deposits
[0040] Aggregates of microalgae cells produced in photobioreactors, generally contain total solids content (TSS) of about 20% and may be collected in any one of a number of different ways. In a batch process, the anode having any aggregates of microalgal cells deposited thereon may be removed from the photobioreactor and the microalgae recovered from the anode either mechanically (e.g. by scraping or skimming) or chemically (e.g. by dissolving in a solvent (e.g. hexanes)). Chemical recovery can further facilitate downstream bio-product extraction. In a continuous process, a skimmer and collection barrel may be added to the photobioreactor.
[0041] The continuous process for microalgae harvesting is promoted by electroflotation in which the microalgae aggregates are moved toward the surface of the culture medium. The voltage and current across the electrodes is set to permit electrolysis of water so that oxygen formed at the anode will help flocculate the microalgae and float the flocculates to the surface. Once at the surface, the flocculated microalgae is more easily collected by a skimmer into a barrel. Electroflotation requires little energy and no chemical flocculants. Since oxygen is formed at the anode and hydrogen is also formed at the cathode, the photobioreactor should be equipped with means to remove these gases, especially the oxygen, in order to increase yield of the microalgae. Temperature, pH, current density and anode geometry may be adjusted to achieve a desired oxygen bubble size for more efficient flotation of the microalgae.
[0042] Typical operation for both batch and continuous processes is based on 24 hour cycles. During the day microalgae is grown, while at night an electrochemical process is applied to harvest the algae. Thus electricity from off-peak power could be utilized, thereby reducing operating costs. Other operations including changing water and other inputs may also done in the absence of solar radiation. Shorter and longer cycle durations may also be used depending on the microalgae species and other considerations including solar irradiation and microalgae concentration.
Example 4
Photobioreactor (PBR) Design for Algae Growth and Harvesting
Comparison Between Plain Glass and TCO-Coated Glass Photobioreactors
[0043] A transparent conducting oxide (TCO) coating blocks the infrared (IR) portion of excitation lamps used as the light source for algae growth in the reactor. Thus, the operating temperature of a TCO-coated glass photobioreactor should be lower than that of a plain glass photobioreactor. Further, because a plain glass photobioreactor is expected to operate at a higher temperature (in the absence of additional cooling steps), algae growth rate in the plain glass reactor should also be less than in the TCO-coated glass bioreactor.
[0044] Two 9 L photobioreactors (PBRs) were constructed using a flat-plate design, one using plain glass walls (Glass-PBR), and one using TCO-coated glass walls (TCO-PBR), where the TCO layers coated on opposing glass walls act as electrodes for further harvesting of the algae. The TCO layer comprised fluorine doped tin oxide (FTO). A Pavlova strain of algae obtained from MRS (Marine Research Station, NRC Halifax) was cultured in the bioreactors in an aqueous culture medium with carbon dioxide introduced into the culture medium by means of a conduit. The culture medium comprised f/2 stock solution and tris(hydroxymethyl)aminomethane. (tris). The reactors were operated for an extended period of time using the same light source to supply light for algae growth. Two sets of two 60 W G25 soft white bulbs were used. Light was supplied under a normal daily photo-regime, and no additional cooling was supplied to either reactor.
[0045] FIG. 4A shows the temperature in each reactor as a function of the time of day, and FIG. 4B shows the concentration of algae as a function of the length of time the photobioreactors are operated. FIG. 4A shows that culture temperature in the Glass-PBR is about 2° C. higher for most of the photo-irradiation period than the temperature in the TCO-PBR. Further, the culture temperature in the Glass-PBR exceeded 27° C. for much of the photo-irradiation period. For most algae strains, operation temperature above 27° C. is detrimental to algae growth, therefore additional cooling is normally required for a Glass-PBR. However, the temperature in the TCO-PBR never exceeded 27° C., thereby reducing cooling requirements normally needed to sustain algae growth in a Glass-PBR. FIG. 4B confirms that algae growth rate obtained using the TCO-PBR is about 2-times faster than what is obtained with the Glass-PBR.
Harvesting
[0046] Harvesting of the algae in the TCO-PBR was accomplished by electroflotation using the TCO layers coated on opposing glass walls act as electrodes using a continuous power with 3 volts and 1 amp. Electroflotation harvesting lead to algae concentration of 3.5 wt % (or 35 g/L), which is within the 2-5 wt % concentration range reported in the literature. Concentration of the harvested algae was estimated using a freeze-dry process. The total electric power consumption of this electroflotation harvesting process was less than 0.3 kWh/m 3 . The low cost and high efficiency of this electroflotation harvesting process is a useful complement to more energy intensive centrifugation processes.
REFERENCES
[0047] The contents of the entirety of each of which are incorporated by this reference.
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[0083] Other advantages that are inherent to the structure are obvious to one skilled in the art. The embodiments are described herein illustratively and are not meant to limit the scope of the invention as claimed. Variations of the foregoing embodiments will be evident to a person of ordinary skill and are intended by the inventor to be encompassed by the following claims.
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In the present invention, a photobioreactor and process for producing and harvesting microalgae involves a vessel for cultivating microalgae that is at least partially transparent to admit light into the vessel. At least a portion of the transparent part of the vessel is coated with a transparent conductive oxide (TCO) layer. The TCO layer is transparent to visible light necessary for algae growth, but is opaque to infrared light thereby reducing thermal heating load in the photobioreactor. The TCO layer also acts as an electrode, which when combined with a counter-electrode can provide a potential difference across at least a portion of the interior of the vessel between the TCO layer and the counter-electrode. The electrode arrangement can be utilized in an electrochemical process (e.g. electrodeposition and/or electroflotation) to dewater and harvest the microalgae in the same apparatus as the microalgae was cultivated.
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TECHNICAL FIELD
[0001] The present invention relates to grinding tools, such as a sander, a grinder, and a polisher, which are machine tools for machining a surface of a workpiece by grinding or polishing the surface. In particular, the present invention relates to a so-called double action grinding tool or a random action grinding tool in which a rotation shaft of a grinding disc is disposed at an eccentric position displaced by a predetermined distance from the axis of a drive shaft.
BACKGROUND ART
[0002] With a grinding tool in which a rotation shaft of a grinding disc is rotatably attached at a position that is eccentric with respect to the axis of a drive shaft of a driving motor, the grinding disc performs an orbital motion around the drive shaft and a rotational motion about the rotation shaft. Therefore, such a grinding tool is usually called a “double action sander grinding tool” or a “random action grinding tool”. FIG. 1 illustrates an eccentric rotation mechanism of such an existing grinding tool. In a grinding tool 1 , an eccentric rotation shaft 4 of a grinding disc 3 , to which an abrasive member 2 is attached, is rotatably attached to a rotary disc 7 through a bearing 9 at a position that is eccentric with respect to an axis 6 of a drive shaft 5 , which is connected to a motor not shown), and the rotary disk 7 is fixed to the drive shaft 5 . Therefore, the grinding tool 1 performs grinding as the grinding disc 3 performs an irregular and complex rotational motion. Therefore, not only grinding can be performed efficiently but also generation of conspicuous marks or patterns, which are called “aurora marks”, can be prevented. Such marks and patterns are generated when a surface is ground by using an ordinary grinding tool that performs regular rotational motion, and they are observed when the surface, which appears to be smooth, is irradiated with light at a certain angle. Such marks and the like are generated because of very small and cyclical irregularities on the ground surface caused by regular rotation. It is possible to solve such a problem by using a grinding disc that performs an irregular rotational motion.
[0003] With the grinding tool 1 , when the motor rotates the drive shaft 5 , the rotary disc 7 rotates, and the grinding disc 3 performs an orbital motion, having an eccentric amount a as the radius, around the axis 6 of the drive shaft 5 . The grinding disc 3 is rotatably attached to the rotary disc 7 through the eccentric rotation shaft 4 and the bearing 9 . As the rotary disc 7 rotates, the grinding disc 3 rotates about an axis 8 of the eccentric rotation shaft 4 due to a driving force generated by friction between the eccentric rotation shaft 4 and the bearing 9 . When the abrasive member 2 attached to the grinding disc 3 is not in contact with a workpiece and the grinding disc 3 is freely rotatable, the rotational speed of the grinding disc 3 about its axis increases to the rotational speed with which the rotary disc 7 is driven. If polishing or grinding is performed by pressing the abrasive member 2 against a surface of the workpiece after the rotational speed of the grinding disc 3 has increased to such a level, the grinding operation is performed impulsively. As a result, marks and scratches are formed on the surface of the workpiece. If the grinding disc 3 is strongly pressed against the workpiece, a brake is applied to the rotation of the grinding disc 3 about its axis, and the braking force becomes larger than a rotational force of the rotary disc 7 , which is generated by friction between the rotation shaft 4 and the bearing 9 . As a result, the rotation of the grinding disc 3 about its axis is stopped, and therefore the grinding performance is considerably reduced.
[0004] In order to prevent such a sharp increase in the rotational speed of the grinding disc about its axis when the grinding disc is unloaded and in order to prevent stopping of the rotation when the grinding disc is pressed against a surface to be ground, brakes and structures for transmitting a driving force for the rotation shaft of the grinding disc have been proposed as described in PTLs 1 to 3. PTL 1 describes a structure with which an increase in the rotational speed of a grinding disc is prevented by friction of braking means, which is an elastic functional ring attached to a casing of a driving motor. When the grinding disc is pressed against a workpiece, the braking means becomes deformed so as to mesh with the grinding disc. Due to such meshing, the grinding disc receives an active driving force from an eccentric member supporter (rotary disc). Therefore, the grinding disc can continue rotating when pressed against the workpiece. However, with this structure, braking for preventing an increase in the rotational speed of the grinding disc about its axis when the grinding disc is unloaded is performed by using friction between the rotation shaft and the elastic functional ring. Such a structure is inefficient because a brake is applied to the grinding disc before the rotational energy of the drive shaft is transmitted to a workpiece, and therefore energy loss is large. Moreover, because a driving force for maintaining a rotational force of the grinding disc is transmitted through the meshing between the braking means attached to the casing and the grinding disc, the grinding disc rotates in a direction opposite to the direction in which the eccentric member supporter (rotary disc) rotates, and the direction of rotation of the grinding disc changes instantaneously during grinding. Therefore, a large shock occurs, and the shock may affect a surface of a workpiece and may cause danger to an operator. Furthermore, the rotational speed of the grinding disc becomes constant relative to that of driving rotation, that is, the grinding disc does not rotate irregularly and smoothly. Therefore, this structure does not provide the function of a grinding tool having an eccentric rotation mechanism.
[0005] PTL 2 describes a grinding tool in which a device for limiting the rotational speed of a sanding disc (grinding disc) is attached to a housing (casing), and the device constantly transmits a force to the sanding disc. In the grinding tool, the device for limiting the rotational speed of the sanding disc is a hollow wheel that is connected through a partial bearing to the housing so as not to be rotatable relative to the housing. The connection can be released so that the sanding disc can freely rotate. Therefore, the rotational speed of the sanding disc can be controlled more smoothly than the grinding tool of PTL 1. However, in order to control the rotational speed and the direction of rotation of the sanding disc, it is necessary to perform precise calculations of at least the following: (1) the magnitudes and the directions of a friction moment of a bearing at an engagement portion and a friction moment between a first engagement portion and a second engagement portion; (2) the magnitude and the direction of a friction moment between an eccentric pin and a sanding disc bearing; and (3) the rotational speed and the rotational torque of a drive shaft. Moreover, the grinding tool, in which connection and disconnection of a locking device are performed and a clutch and the like, are used, has a complex mechanism. Furthermore, as in the case of PTL 1, a large shock occurs because the direction of rotation of the sanding disc changes instantaneously during a grinding operation, and the shock may affect a surface of a workpiece or may cause danger to an operator.
[0006] The grinding tool described in PTL 3, in which a driving force is directly transmitted to the grinding disc (grinding pad), controls rotation by applying forces in the axial direction to an inner race and an outer race of a bearing. Therefore, the grinding tool has a problem about the durability, which arises due to the structure of the bearing.
CITATION LIST
Patent Literature
[0007] PTL 1: Japanese Unexamined Patent Application Publication No. 2001-219353
[0008] PTL 2: Japanese Unexamined Patent Application Publication No. 2002-192452
[0009] PTL 3: Japanese Unexamined Patent Application Publication No. 3-201548
SUMMARY OF INVENTION
Technical Problem
[0010] The present invention provides a grinding tool in which an eccentric rotation shaft of a grinding disc is rotatably attached to a position that is eccentric with respect to the axis of a drive shaft of a driving motor, the grinding tool having the following advantage. The rotational speed of the grinding disc about its axis does not considerably increase when grinding is not performed and the grinding disc is unloaded, and an appropriate driving force is transmitted and the rotational speed of the grinding disc about its axis does not considerably decrease when grinding is performed and a load is applied to the grinding disc. Thus, the rotational speed of the grinding disc about its axis is controlled in a stable range, so that a workpiece can be efficiently ground and marks or patterns are not generated on a ground surface.
Solution to Problem
[0011] According to the present invention, in a grinding tool in which an eccentric rotation shaft of a grinding disc (to which an abrasive member is attached) is attached through a bearing to a rotary disc at a position that is eccentric with respect to an axis of a drive shaft connected to a motor, the rotary disc being fixed to the drive shaft, the grinding tool includes a clutch including a grinding-disc-side clutch member and a rotary-disc-side clutch member that are connected to each other along a sliding surface that is capable of sliding and capable of transmitting a driving force, the grinding-disc-side clutch member being attached to the grinding disc or to the eccentric rotation shaft fixed to the grinding disc, the rotary-disc-side clutch member being attached to the rotary disc.
[0012] It is preferable that the sliding surface include at least a set of conical shapes. Moreover, it is preferable that one of the clutch members be made of a plastic material and the other clutch member be made of a metal material. The plastic material is a material having high heat resistance and high wear resistance. For example, a fluorocarbon resin, PEEK (polyether ether ketone), a polyamide-imide, or a fiber reinforcement of such a material is preferably used. As the metal material, a metal such as steel, a copper alloy, an aluminum alloy, or a white metal, or a sintered metal impregnated with a liquid lubricant is preferably used.
[0013] In the grinding tool according to the present invention, the grinding-disc-side clutch member, which is attached to the grinding disc or to the eccentric rotation shaft, and the rotary-disc-side clutch member, which is attached to the rotary disc, are connected so as to be capable of sliding and capable of transmitting a driving force. That is, these clutch members are in a so-called partially engaged state. Therefore, a driving force for the rotary disc is transmitted by the friction of the sliding surface of the clutch members. Moreover, the rotation of the eccentric rotation shaft about its axis is controlled, because the friction of the sliding surface is larger than the friction of the bearing.
Advantageous Effects of Invention
[0014] The clutch members of the grinding tool described above have a sliding surface that is capable of sliding and capable of transmitting a driving force. When grinding is not performed and the grinding disc is unloaded, the sliding surface of the clutch members performs a braking function to prevent a considerable increase in the rotational speed of the grinding disc about its axis. When grinding is performed and a load is applied to the grinding disc, a driving force from the rotary disc is transmitted to the grinding disc by using the friction of the sliding surface, and therefore the rotational speed of the grinding disc about its axis can be maintained. Thus, during a grinding operation, the rotational speed of the rotary disc, that is, the rotational speed of the grinding disc, can be adjusted by adjusting the rotational speed of the motor, and the rotational speed of the grinding disc about its axis can also be adjusted by appropriately adjusting a force with which the abrasive member attached to the grinding disc is pressed against a surface of a workpiece. Accordingly, the grinding disc can perform a rotational motion in which a rotational motion about its axis and an orbital motion are combined in a complex way.
[0015] Therefore, by using the grinding tool according to the present invention, when grinding a workpiece by a large grinding amount, a smoothly ground surface can be obtained despite the large grinding amount due to the complex and active rotational motion of the grinding disc. Moreover, a beautifully delustered surface can be obtained, and the operation can be efficiently performed. Furthermore, buffing can be performed without generating marks and patterns on a buffed surface. With the grinding tool, although rotation of the grinding disc is complex and irregular, the direction of rotation of the grinding disc about its axis is the same as the direction of rotation of the rotary disc, so that driving energy loss is small, shock due to an instantaneous change in the direction of rotation does not occur during grinding, and a grinding operation can be performed safely. Accordingly, the grinding tool according to the present invention can be preferably used as a tool for grinding, which is called a grinder or a sander, and as a tool for polishing, which is called a polisher.
BRIEF DESCRIPTION OF DRAWINGS
[0016] FIG. 1 illustrates an eccentric rotation mechanism of an existing grinding tool.
[0017] FIG. 2 is a sectional view of clutch members attached to a rotary disc and to an eccentric rotation shaft.
[0018] FIG. 3 is a sectional view of clutch members according to another embodiment.
[0019] FIG. 4 is a top view of a rotary disc to which the clutch members illustrated in FIG. 3 are attached.
[0020] FIG. 5 is a sectional view of clutch members attached to a rotary disc and to a grinding disc.
[0021] FIG. 6 is a sectional view of an embodiment in which part of the clutch members illustrated in FIG. 2 is modified.
DESCRIPTION OF EMBODIMENTS
[0022] Embodiments of the present invention will be described. in detail with reference to the drawings.
[0023] FIG. 2 is a sectional view of clutch members attached to a rotary disc and to an eccentric rotation shaft according to the present invention. Although not illustrated in FIG. 2 , a grinding disc 3 is fixed to an end of an eccentric rotation shaft 4 , and an abrasive member 2 is attached to the grinding disc 3 as in FIG. 1 . Likewise, although not illustrated, a driving motor is connected to an end of a drive shaft 5 . A rotary disc 7 is rotated by a driving force of a motor. As described above with reference to FIG. 1 , the eccentric rotation shaft 4 is attached to a position that is eccentric with respect to the drive shaft 5 . When the motor rotates the drive shaft 5 , the rotary disc 7 rotates and the eccentric rotation shaft 4 performs an orbital motion. Moreover, the eccentric rotation shaft 4 , which is attached to the rotary disc 7 through a bearing 9 , performs a rotational motion about its axis.
[0024] In FIG. 2 , the eccentric rotation shaft 4 is attached to the rotary disc 7 through the bearing 9 . A grinding-disc-side clutch member 12 is fixed to the eccentric rotation shaft 4 using a clutch attachment screw 14 . A rotary-disc-side clutch member 11 and push springs 16 are attached to the rotary disc 7 in such a way that the rotary disc 7 and the clutch member 11 are movable relative to each other and elastic forces of the push springs 16 can be transmitted to the clutch member 11 . The rotary-disc-side clutch member 11 and the grinding-disc-side clutch member 12 are disposed so as to be in close contact with each other along a sliding surface 13 having a conical shape. The sliding surface 13 is capable of sliding and capable of transmitting a driving force. The friction of the sliding surface 13 is larger than the friction of the bearing 9 . When the rotational speed of the eccentric, rotation shaft 4 about its axis increases considerably, the sliding surface 13 functions as a brake. When the rotational speed of the eccentric rotation shaft 4 about its axis decreases, the sliding surface 13 functions to transmit a driving force. A force that presses the clutch members 11 and 12 against each other can be adjusted by adjusting the elastic forces of the push springs 16 . Braking power and the ability to transmit a driving force can be increased by using springs having larger elastic forces or by compressing the springs more strongly. Braking power and the ability to transmit a driving force can be decreased by making adjustment in the opposite way. The eccentric rotation shaft 4 is attached through the bearing 9 in such a way that a gap 15 is formed between the rotary disc 7 and the grinding-disc-side clutch member 12 , so that the function of the sliding surface 13 described above may not be hindered.
[0025] As described above, the clutch members 11 and 12 are partially engaged all the time, and the sliding surface 13 is capable of sliding and capable of transmitting a driving force. The grinding tool, having such a combination of clutch members, has high grinding performance and workability as described above. It is preferable that to sliding surface 13 have a conical shape, with which a large surface area can be easily provided. However, the shape of the sliding surface is not particularly limited, and may be disc-shaped.
[0026] FIGS. 3 and 4 illustrate clutch members according to another embodiment. FIG. 3 is a sectional view, and FIG. 4 is a top view. In the clutch members according to the present embodiment, a sliding surface 23 includes a plurality of conical shapes. A grinding-disc-side clutch member 22 is fixed to an eccentric rotation shaft 4 , and a rotary-disc-side clutch member 21 is formed by cutting a rotary disc 7 . Because the sliding surface 23 includes four conical surfaces, the rotary disc 7 is divided along a segment surface 7 b, a segment 7 a is removed, and the eccentric rotation shaft 4 is set while fixing the grinding-disc-side clutch member 22 to the eccentric rotation shaft 4 . Then, the segment 7 a, which has been removed, is fixed to the rotary disc 7 using connection screws 25 . The grinding-disc-side clutch member 22 is attached to the eccentric rotation shaft 4 using an attachment screw 24 . The rotary-disc-side clutch member 21 may be made not by cutting the rotary disc 7 but by fixing a clutch member on which the sliding surface 23 having the same shape has been formed to the rotary disc 7 . In the embodiment illustrated in FIG. 3 , a bearing 9 is not necessary because the clutch members also function as a bearing. However, a metal bearing is used in the embodiment.
[0027] FIG. 5 illustrates an embodiment in which a grinding-disc-side clutch member is directly attached to a grinding disc. In this embodiment, a grinding-disc-side clutch member 32 is attached to a grinding disc 3 . In FIG. 5 , a clutch attachment screw 34 is screwed into an eccentric rotation shaft 4 . Alternatively, the attachment screw 34 may be screwed into the grinding disc 3 . A rotary-disc-side clutch member 31 is fixed to an upper surface of a rotary 7 . The clutch members 31 and 32 are disposed so as to be in close contact with each other along a sliding surface 33 having a conical shape. The rotary-disc-side clutch member 31 and the rotation shaft 4 are not in direct contact with each other, and a gap 35 is formed therebetween. The grinding disc 3 is connected to the rotary disc 7 along the sliding surface 33 . As with the rotary-disc-side clutch member 11 in FIG. 2 , the rotary-disc-side clutch member 31 may be attached to the rotary disc 7 in such a way that they are movable relative to each other and the rotary-disc-side clutch member 31 can be pressed against the grinding-disc-side clutch member 32 by using push springs.
[0028] FIG. 6 is a sectional view of an embodiment in which part the clutch members illustrated in FIG. 2 is modified. In the present embodiment, an eccentric rotation shaft 4 for driving a grinding disc is attached to an inner casing 40 , which is connected to a rotary disc 7 , through a bearing 9 . A sliding surface 43 of the clutch members includes a combination of two conical shapes. A grinding-disc-side clutch member 42 has a convex ring-like shape, and a rotary-disc-side clutch member 41 has a concave ring-like shape. The convex and concave surfaces of the clutch members, which are in close contact with each other, form the sliding surface 43 . The grinding-disc-side clutch member 42 is attached to the eccentric rotation shaft 4 using a clutch attachment screw 44 . The rotary-disc-side clutch member 41 is attached to the rotary disc 7 through a push spring 46 . The inner casing 40 is connected and fixed to the rotary disc 7 by a pressing force of the push spring 46 , which is applied via the clutch members 41 and 42 and the bearing 9 , and by retention using a snap ring 47 . With such a structure, in the case where the bearing 9 is used, damage to the bearing due to a force in the axial direction can be prevented.
[0029] As in other embodiments, the sliding surface 43 according to the present embodiment is capable of sliding and capable of transmitting a driving force. The friction of the sliding surface 43 is larger than the friction of the bearing 9 . When the rotational speed of the eccentric rotation shaft 4 about its axis increases considerably, the sliding surface 43 functions as a brake When the rotational speed of the eccentric rotation shaft 4 about its axis decreases, the sliding surface 43 functions to transmit a driving force. A force that presses the clutch members 41 and 42 against each other can be adjusted by adjusting the elastic forces of the push spring 46 . In the present embodiment, it is preferable that the grinding-disc-side clutch member 42 be made of a plastic material and the rotary-disc-side clutch member 41 be made of a metal material. In present embodiment, a polyamide-imide is used as the plastic material, and steel (S45C) is used as the metal material. With this structure, as the grinding tool is used over a long period, the grinding-disc-side clutch member 42 , which is made of a plastic material, wears along the sliding surface. As the wear develops, the rotary-disc-side clutch member 41 , which is made of a metal material, advances upward and may cause trouble in the rotation mechanism. However, with the embodiment illustrated in FIG. 6 , such an upward advancement of the rotary-disc-side clutch member 41 can be limited, because a gap 45 , which is formed between a peripheral edge portion of the rotary-disc-side clutch member 41 and a lower edge portion of the inner casing 40 , becomes narrower and eventually eliminated. The presence/absence of the gap 45 may be used as an indicator of a replacement time of the grinding-disc-side clutch member 42 .
[0030] In any of the embodiments described above, they grinding disc 3 and the rotary disc 7 are connected to each other and partially engaged with each other along a sliding surface that is capable of sliding and capable of transmitting a driving force. Therefore, during a grinding operation, the grinding disc 3 performs a rotational motion in which a rotational motion and an orbital motion are combined in a complex way as described above, so that an efficient grinding operation can be realized.
[0031] Metals and plastic materials can be used as the materials of the clutch members. As described above, it is preferable that a combination of a plastic material and a metal material be used. As the plastic material, a material having high heat resistance and high wear resistance is used. As described above, it is preferable that the plastic material be a fluorocarbon resin, PEEK (polyether ether ketone), a polyamide-imide, or a fiber-reinforcement of such a martial. It is preferable that the fiber be glass fiber or carbon fiber. It is preferable that the fluorocarbon resin be PTFE (polytetrafluoroethylene). Alternatively, a copolymer of tetrafluoroethylene and chlorotrifluoroethylene, ethylene, hexafluoropropylene, or the like may be used. Examples of other usable plastic materials haying high heat resistance and high wear resistance include polyacetal (polyoxymethylene), polyetherketone, and polyethersulfone. Examples of usable metal materials include steel; a copper alloy, such as bronze, lead bronze, phosphor bronze, or the like; an aluminum alloy; a white metal; an oil-impregnated sintered metal material, such as that of iron, a copper alloy, or an iron copper alloy; and a sintered material that is a combination of such a metal and graphite. The clutch members are manufactured by molding, casting, or cutting such a material. As necessary, a lubricant such as a lubrication oil may be applied to the sliding surface.
[0032] The present invention is not limited to the embodiments described above, and the embodiments may be modified within the spirit and scope of the present invention.
REFERENCE SIGNS LIST
[0000]
1 existing grinding tool
2 abrasive member
3 grinding disc
4 eccentric rotation shaft
5 drive shaft
6 axis of drive shaft
7 rotary disc
7 a rotary disc segment
7 b rotary disc segment surface
8 axis of eccentric rotation shaft
9 bearing
11 rotary-disc-side clutch member
12 grinding-disc-side clutch member
13 sliding surface
14 clutch attachment screw
15 gap
16 push spring
21 rotary-disc-side clutch member
22 grinding-disc-side clutch member
24 clutch attachment screw
25 rotary disc connection screw
31 rotary-disc-side clutch member
32 grinding-disc-side clutch member
33 sliding surface
34 clutch attachment screw
35 gap
40 inner casing
41 rotary-disc-side clutch member
42 grinding-disc-side clutch member
43 sliding surface
44 clutch attachment screw
46 gap
45 push spring
47 snap ring
a eccentric amount
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A grinding tool with an eccentric rotation shaft of a grinding disc with attached grinding material installed via a hearing at a position that is shifted from the central drive shaft line of a rotating disc fixed on a drive shaft, comprises a clutch in which a grinding disc-side clutch component member installed on the grinding disc or on the eccentric rotation shaft that is fixed to the grinding disc and a rotating disc-side clutch component member installed on the rotating disc are linked via a sliding surface capable of sliding and of transmitting the drive force.
The rotation rate of the grinding disc is limited to a stable range of rotation rates, preventing extreme elevation in the rotation rate and extreme reduction in the rotation rate; the workpiece is ground efficiently; and the tool does riot generate marks or patterns on the ground surface.
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BACKGROUND OF THE INVENTION
1. Field of the Invention.
The present invention relates to fireplace accessories in general and to a fireplace tool, in particular, for grasping and moving fireplace logs.
2. Description of the prior art.
Fireplace tools for lifting and munipulating fireplace logs are well known in the art and have experienced ever increasing utilization as wood burning fireplaces have filled the gap for residential heating requirements. Where such fireplace tools were once considered decorative and ornamental implements, they are now accepted as useful and even necessary aids for obtaining maximum use and efficiency from wood burning fireplace installations.
It has been found that the previous emphasis on aesthetic rather than utilitarian features of the fireplace tools has resulted in implements which are partially or wholly inoperative. For example, difficulty has been experienced in producing a fireplace tool with the ability to accept a wide range of log sizes. In addition, some tools have been damaged by repeated contact with the high temperatures associated with a well-stoked wood fire. The size of the tool is also a critical factor in order to position the operator a safe distance from the fire itself. Finally, many fireplace users, particularly those advanced in years or of unsound health to whom the warmth supplied by a wood burning fireplace may be the only source of residential heating, have expressed dissatisfaction with prior art fireplace tools which are heavy and cumbersome. This drawback has led to makeshift ways of munipulating logs in the fireplace, often compromising the safety and health of the user as well as endangering property from wayward sparks and the like.
SUMMARY OF THE INVENTION
The fireplace tool contemplated by the present invention overcomes the limitations of prior art apparatus for manipulating fireplace logs by providing a simple, safe and easily operated device which can accept a wide range of log sizes, and in addition can be operated amidst the fireplace flames with minimum danger to person or property.
In a preferred embodiment, the fireplace tongs comprise a hollow tubular stationary member having at one end a looped handle adapted to be grasped by one hand of the operator, and having a pair of spaced apart parallel downwardly depending arcuate claw-like tines attached at its opposite end. The stationary member slidably receives a telescoping member having one end terminating in a single downwardly depending arcuate claw-like tine of opposite curvature to the tines associated with the stationary member. The telescoping member may be secured to the stationary member by means of a loop chain to prevent their separation. In addition, the end of the telescoping member adjacent the downwardly depending tine is formed in the shape of a probe point for adjusting logs and the like.
An elongate rod-like lift member terminating at one end in a looped handle adapted to be grasped by one hand of the operator is pivotally attached at its opposite end to the upper side of the telescoping member opposite the downwardly depending tine. By grasping the looped handles, the operator may lower the downwardly depending tines over a log to be manipulated, and by drawing the looped handle attached to the lift member toward the operator, bring the downwardly depending tines into abutting contact with the log on opposite sides thereof. The log may then be lifted and moved to the proper position by holding the looped handle associated with the stationary member fixed, this handle acting as a pivot point, and further drawing back on the looped handle associated with the lift member, thereby producing considerable leverage and mechanical advantage with little effort on the part of the operator. To release the log, the looped handle associated with the lift member is pushed away from the operator, therby bringing the tines out of contact with the outer surface of the log.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the fireplace tool of the present invention.
FIG. 2 is a fragmentary side elevation view, partially in cross-section, of a preferred embodiment of the fireplace tool of the present invention shown in the closed or log grasping position.
FIG. 3 is a front elevation view of a preferred embodiment of the fireplace tool of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1, a perspective view of a preferred embodiment of the fireplace tool of the present invention, shown generally at 1, is illustrated. The tool comprises a hollow tubular stationary member 2 having located at one end a horizontal looped handle 3 adapted to be grasped by one of the operator's hands. While for purposes of an exemplary showing, tubular stationary member 2 has been illustrated in the form of a hollow box-like enclosure, it will be understood that the actual cross-sectional shape of stationary member 2 is not critical, and may take other configurations, such as cylindrical, elliptical or the like. Stationary member 2, as well as other parts of the tool to be described, may be constructed from iron, steel, aluminum or any other flame proof and light-weight material. Handle portion 3 may comprise an integral part of stationary member 2, or may be formed from a separate hollow or solid metallic rod, for example, and attached to tubular stationary member 2 by welding or the like.
A flat horizontal support bar 4 is attached approximately at its midpoint to the lower surface of tubular stationary member 2 at the end of member 2 opposite that containing handle 3. Depending downwardly from either end of support bar 4 is a claw-like tine 5. Each tine comprises a vertical straight portion 6, the upper end of which is attached to support bar 4 by welding or the like, and an arcuate portion 7 depending from straight portion 6. Arcuate portion 7 is configured to bend toward the front end of stationary member 2, i.e., away from handle portion 3, the curvature of arcuate portions 7 being such as to abuttingly engage the outer surface of the usual sizes of logs used in a residential wood burning fireplace. Downwardly depending tines 5 are substantially parallel and are spaced apart a distance for accommodating the usual length of logs used in a residential wood burning fireplace. While tines 5 and support bar 4 have been described as separate structures, joined by welding or the like, it will be understood that they may be formed from a continuous bar-like stock, tine portions 5 being formed by right angle bends formed in the bar stock.
A telescoping member 8 having the same general exterior configuration as the interior configuration of stationary member 2, is slidably received within stationary member 2. Telescoping member 2 may be constructed of tubular material, as is best seen in FIG. 2, or may be of solid construction as desired. Telescoping member 8 is prevented from becoming disengaged from stationary member 2 by a loop chain or the like joining members 2 and 8. In order to prevent chain 9 from becoming entangled during operation of the tool, it has been found advantageous to locate chain 9 within the hollow interiors of stationary member 2 and telescoping member 8. The ends of chain 9 may be secured to the walls of members 2 and 8 by screws, rivets, pins or the like.
The opposite end of telescoping member 2 is formed in the shape of a pointed probe 10 which can be used to adjust the fire wood within the fireplace. While the probe point 10 has been illustrated in a four-sided pyramid shape, it will be understood that the probe may also be configured as conical, etc.
Attached to the lower surface of telescoping member 8 adjacent probe point 10 is a downwardly depending claw-like tine 11, similar in construction to tines 5. Tine 11 comprises a straight vertical portion 12 and an arcuate portion 13. Arcuate portion 13 is configured to curve toward tines 5 for abutting the opposite surface of the fireplace logs. As illustrated in FIG. 1 in connection with a typical log 14 shown in phantom, tine 12 assumes a position approximately midway between tines 5 but on the opposite side of log 14. This arrangement assures extremely stable contact with log 14 thereby assuring safe and dependable munipulation of the log.
Although for purposes of an exemplary showing, fireplace tool 1 has been illustrated and described as having a pair of spaced claw-like tines 5 depending downwardly from either end of support bar 4, and telescoping member 8 is supplied with a similar oppositely disposed downwardlly depending tine 11, it will be understood that fireplace tool 1 may be constructed with the relative position of tines 5 and 11 reversed; i.e. support bar 4 bearing a pair of spaced claw-like tines 5 curving rearwardly toward handle 3 may be affixed to the forwardmost end of telescoping member 8, while a single downwardly depending forwardly curved tine 11 may be attached to the lowermost surface of stationary member 2. Furthermore, it will be understood that the present invention is contemplated to include the embodiment wherein downwardly depending tine 11 is replaced by a substantially horizontal support bar similar to support bar 4 attached at its approximate mid-point to the forwardmost end of telescoping member 8 and containing a pair of downwardly depending spaced claw-like tines similar to tines 5 but curving rearwardly toward handle 3.
An elongate rod-like lift member 15 is pivotally attached to the upper surface of telescoping member 8 adjacent probe point 10. The upper end of lift member 15 terminates in a looped handle 16 adapted to be grasped by one of the operator's hands. Lift member 15 and handle 16 may be formed of a continuous rod-like material, or may be constructed separately and joined by welding or the like. The lower end of lift member 15 is formed in the shape of a circular loop 17 having an aperture 18 therethrough for accepting a pivot pin 19. Aperture 18 and pivot pin 19 are so dimensioned as to allow lift member 15 to freely pivot about pivot pin 19. The ends of pivot pin 19 are non-rotatably supported by a pair of parallel upstanding journals 20 rigidly affixed, by welding or the like, to the upper surface of telescoping member 8.
In operation, the user grasps handle 3 associated with stationary member 2 in one hand, and handle 16 associated with lift member 15 in the other. By holding handle 3 stationary and pushing slightly on handle 16, telescoping member 8 may be slidably extended from stationary member 2 to the position shown in phantom in FIG. 2. In this position, the tool may be lowered over the log to be manipulated such that the lower surface of telescoping member 8 rests upon the upper surface of the log to be manipulated, such as that depicted at 14 in FIG. 2. Still holding handle 3 stationary, the user pulls on handle 16, thereby telescoping inwardly telescoping member 8 and stationary member 2 until the oppositely disposed tines are brought into abutting contact with the opposite surfaces of log 14. It will be observed that tines 5 and 11 are so dimensioned as to accept a wide range of log sizes therebetween. To lift the log, handle 3 is held stationary and further pulling pressure is applied to handle 16 to cause the entire tool to pivot about handle 3. Depending upon the angle formed between lift member 15 and the axis of stationary member 2 and telescoping member 8, considerable leverage and mechanical advantage can be applied to lift and manipulate sizable logs with minimum effort. When the log has been moved to the desired location, pressure is released on handle 16, lowering log 14 into place. Thereafter, by pushing on handle 16 while holding handle 3 stationary, tines 5 and 11 may be separated, reversing the procedure described hereintofore, to release log 14 and remove the tool.
For purposes of storage, telescoping member 8 may be moved to the fully retracted position, thereby minimizing the overall length of the tool. In addition, lift member 15 may be lowered substantially parallel with stationary member 2 and telescoping member 8 so that the overall depth of the tool is minimized. It will be understood that the tool may be painted or otherwise decorated to provide a pleasing appearance when stored in association with a wood burning fireplace.
It will be understood that various changes in the details, materials, steps and arrangements of parts, which have herein been described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in appended claims.
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Fireplace tongs comprising a tubular stationary member including a handle located at one end, and a telescoping member having one end slidably received within the stationary member. The stationary and telescoping members include downwardly depending claw-like arcuate tines for gripping a log therebetween. An elongated handle is pivotally attached to one end of the upper side of the telescoping member and terminates at its opposite end in a handle. The telescoping member is shiftable between an open and a closed position for accepting and firmly holding a log.
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FIELD OF THE INVENTION
[0001] The invention falls basically in the field of computer implemented inventions wherein more precisely algorithmic solutions, graph rewriting, recognizer-automata, artificial intelligence and universal algebra. Suggested patent class: Artificial Intelligence 706/19,/13,/46.
BACKGROUND OF THE INVENTION
[0002] The whole time widening need of systems is requiring knowledge of common structures in systems before creating fast, exact, controllable and sufficiently comprehensive solving algorithms of problems in those systems. In all human fields in data processing, especially in physics and construction there are numerous environments where the data flow can not be restricted in order to get sufficient model to handle with the tasks, e.g. mathematical equation groups with infinite number of variables allowed to be systems themselves and physical phenomena where solution models would require to allow unlimited dimensions (in the field theories of small quantum particles or in universal large astronomical ones). Models in meteorology and models for handling with populations, biological organizations or even combinations in genetic codes call for common approach in problem solving especially in cases where independent in- or out-data flows are required to be unlimited by numbers or volumes, where controlled memory flow is a key word. Naturally one can imagine numerous other fields where a general model for problem solving would be desirable.
[0003] The method of this invention guarantees a universal way to solve problems even in the cases where data components are unlimited by numbers and volumes, and being due to our unlimited handling and altering stages also in the cases where solutions are not possible to detect in a denumerable way derived from preceding solutions. The method takes in use generalized graphs in describing subjects of problems which are thoroughly introduced, and rewriting of graphs is the basis to construct parallel altering transducers as macros of solutions for examined problems. The abstract cover type for original problem in order to control the comprehensiveness of searching process can freely be chosen, to be the most conceivable one, too. Therefore a special effort is focused to deal with the relations between interacting rewriting types and constructing abstract sisters in the most general cases. The validity and appropriateness of the solutions are checked by recognizers and limit demands bounded to the problems.
BRIEF SUMMARY
[0004] First we present necessary preliminary definitions for unlimited, infinite and undenumerable cases, followed by the definitions for the construction of graph for arbitrary number of nodes with in- and outputs. Then we give the exact representation for rewriting systems and transducers, the nodes of which being rewrite systems. The necessary consideration is given to definitions for generalized equations. The definition of problem and its solution is introduced in terms of graph, recognizability and transducers fulfilling limit demands. Then the partition of graph and the abstraction relation between concept graphs are introduced, needed in searching the fitting partial solutions from memory. “Altering macro renetting system”-theorem is introducing the necessary equation matching each step of the solution process between graphs and their substances. Parallel theorem establishes the invariability of the abstraction relation and also the construction for necessary algorithms for abstract sisters. “Process summarization”-figure illustrates the process in constructing the desired transducer for the original mother graph from the known ones in memory. “Abstraction closure”-theorem proves that the obtained solving transducers represent all possible solutions for the problem. Finally we present the extension of the rules in searching solving transducers, in the cases where covers of mother graphs differ from partitions, and in the same time a system to control comprehensiveness of remembrance hunting is introduced. For that purpose cover renetting systems are defined as generalizations of partition ones, and partition is replaced by concept of cover renetting result consisting of sequential parts of cover in depth dimension, partly replaced by each other. By taking to account partition relations cover reversely labelling renetting is used to transform results of “right sides distinct”-cover renetting for mother graphs to partitions of that mother graph generated by generalized partition renetting systems. “Altering macro renetting”-theorem is generalized to macro transducers in regard to “right sides distinct”-cover renetting systems. After introducing characterizations for generalized abstraction relation fitting cover results, parallel and “abstraction closure” theorems are widened to handle also with general interacting cover renetting of original problem.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 5 . 5 . 1 (The first page view) is the process summarization figure describing solution process order and the relations between known TD:es and TD:es solving the given problem.
[0006] FIG. 1 . 2 . 2 . 01 describes an example of finite graphs.
[0007] FIG. 1 . 2 . 2 . 07 . 1 is an example of closely neighbouring nets.
[0008] FIG. 1 . 2 . 2 . 07 . 2 is an example of nets totally isolated from each other
[0009] FIG. 1 . 2 . 2 . 12 is a figure of nodes dominating others.
[0010] FIG. 1 . 2 . 2 . 13 . 1 is an example of OWR-loop.
[0011] FIG. 1 . 2 . 2 . 13 . 2 describes a bush.
[0012] FIG. 1 . 2 . 4 . 5 . 1 describes a transformator graph over a set of realizations.
[0013] FIG. 1 . 2 . 4 . 5 . 2 is the figure of a realization process graph of the transformator graph in FIG. 1 . 2 . 4 . 5 . 1 .
[0014] FIG. 1 . 2 . 4 . 5 . 3 is an example of a transformation graph of the transformator graph in FIG. 1 . 2 . 4 . 5 . 1 .
[0015] FIG. 1 . 3 . 06 clarifies an apex of a net.
[0016] FIG. 1 . 3 . 07 is a figure of a broken enclosement of an unbroken net.
[0017] FIG. 1 . 3 . 10 describes a cover of a net.
[0018] FIG. 1 . 3 . 11 . 1 is a figure of a saturating cover.
[0019] FIG. 1 . 3 . 11 . 2 is an example of a natural cover.
[0020] FIG. 1 . 3 . 12 describes a partition of a net.
[0021] FIG. 1 . 5 . 01 describes an enclosement of a net, where rewrite takes a place in that net.
[0022] FIG. 1 . 5 . 02 . 1 demonstrates application of manoeuvre mightiness and manoeuvre letter increasing rules.
[0023] FIG. 3 . 1 . 6 . 1 is the description for the proof of “a characterization of the abstraction relation”-theorem 3.1 in the case where the outside arities in the other concept are in neighbouring elements of a partition.
[0024] FIG. 3 . 1 . 6 . 2 is the description for the proof of “a characterization of the abstraction relation”-theorem 3.1 in the case where the outside arities in the other concept are in elements of a partition totally isolated from each other.
[0025] FIG. 3 . 1 . 9 . 1 describes incomplite images of ‘minimal’ realization process graphs of a TG over a set of TD:es in the class of the abstraction relation.
[0026] FIG. 3 . 1 . 9 . 2 describes forming a class of the abstraction relation by transformation graphs outdominated (‘centered’) by substances.
[0027] FIG. 3 . 2 . 1 describes constructing macro RNS.
[0028] FIG. 3 . 3 . 4 describes the relation between parallel TD:es.
[0029] FIG. 3 . 4 . 1 is figuring the tree formation of a denumerable class of the abstraction relation.
[0030] FIG. 4.1 is clarifying the nature of the invariability of a relation in processing a pair of TD:es.
[0031] FIG. 4.2 is a complicated version of FIG. 4.1 with more than one element in the processed relation.
[0032] FIG. 4 . 3 . 1 describes a situation of FIG. 4.1 , where the relation is compiled by covers.
[0033] FIG. 4 . 3 . 2 is a figure of a 3-successive net and an effect of rewriting in totally isolated elements of a cover.
[0034] FIG. 5 . 3 . 1 illustrates PRNS as a special case of more general cover RNS.
[0035] FIG. 5 . 3 . 2 is figuring differences between cover orders and partition RNS:es.
[0036] FIG. 5 . 4 . 2 illustrates transferring information of application of a rule to GPRNS-related form by cover rewriting and reversely labelling RNS.
[0037] FIG. 5 . 5 . 0 “Memory Hunting” illustrates iterative process of probing known transducers in memory by cover rewriting systems in order to transform them by cover reversely labelling RNS:es.
[0038] FIG. 5 . 6 . 3 describes a typical phase of iteration in interacting RNS of type GCRNS.
DETAILED DESCRIPTION OF THE INVENTION
§ 1. Preliminaries
[0039] 1.1. Sets and Relations
[0040] [1.1.01] We regularly use small letters for elements and capital letters for sets and when necessary bolded capital letters for families of sets. The new defined terms are underlined when represented the first time.
[0041] [1.1.02] We use the following convenient symbols for arbitrary element a and set A in the meaning:
[0000] aε A “a is an element of A or belongs to A or is in A”
a ∉ A “a does not gelong to A”
∃a ε A “there is such an element a in A that”
∃|a ε A “there is exactly one element a in A”
∃|ε A “there exists none element a in A”
∀a ε A “for each a belonging to A”
“then it follows that”
“if and only if”, shortly “iff”
[1.1.03] {a:*} or (a:*) means a conditional set, the set of all such a-elements which fulfil each condition in sample * of conditions, and nonconditional, if sample * does not contain any condition conserning a-elements.
[1.1.04] Ø means empty set, the set with no elements. A set of sets is called a family. For set the notation {a i : i ε } is an indexed set (over ). Set {a i : i ε } is {a}, if a i =a whenever iε . If there is no danger of confusion we identify a set of one element, singleton, with its element. It is noticable that {Ø} is a singleton set.
[1.1.05] The number of the elements in set A, mightiness of A, is denoted by |A|.
[1.1.06] A minimal/maximal element of a set is an element which does not contain/is not a part of any other element of the set. The set of the minimal/maximal elements of set A is denoted by min A/max A, respectively.
[1.1.07] For arbitrary sets A and B we use the notations:
A ⊂ B or B ⊃A “A is a subset of B (is a part of B or each element of A is in B) or B includes A” A ⊂ B “A is not a part of B (or there is an element in A which is not in B)” A⊂B or B⊃A “A is a genuine subset of B” meaning “A ⊂ B and (∃b εB) b ∉ A” A⊂B “A is not a genuine subset of B” A≠B “A is not the same as B” A c or A “is the complement of A” meaning set {a:aεA} A∪B “the union of A and B” meaning set {a:aεA or aεB} A∩B “the intersection of A and B” meaning set {a:aεA, aεB}. If A∩B=Ø, we say that A and B are distinct with each other, or outside each other. A\B “A excluding B” meaning {a:aεA, a∉B}. Two sets the intersection of which is empty, is said to be separate from each other.
[1.1.08] P(A) symbolies the family of all subsets of set A.
[1.1.09] The set of natural numbers {1,2, . . . } is denoted by symbol |N, and |N 0 =|N∪{0}.
[1.1.10] Notice that for sets A 1 and A 2 and samples of conditions * 1 and * 2
{a:aεA 1 , * 1 } ⊂ {a:aεA 2 , * 2 }
if (A 1 ⊂ A 2 and * 1 =* 2 ) or (A 1 =A 2 and * 2 ⊂ * 1 )
[0052] [1.1.11] The notation ∪(A i : iε ) is the union {a:(∃iε ) aεA i } and
∩(A i : iε ) is the intersection {a:(∀i ε ) aεA i }
for indexed family {A i : iε }. For any family we define:
∪ =∪(B:Bε ) ∩ =∩(B:Bε )
[1.1.12] If a set is a subset of the union of a family, we say that the family covers the set or is a cover of the set, and if furthermore the union is a subset of the set, the family saturates the set.
[1.1.13] Set p of ordered pairs (a,b) is a binary relation, where a is a ρ-domain of b and b is a ρ-image of a. D(ρ)={a:(a,b)ερ} is the domain (set) of ρ (ρ is over D(ρ)), and ρ)={b:(a,b)ερ}} is its image (set). Instead of (a,b)ερ we often use the notation aρb. If the image set for each element of a domain set is a singleton, the concerning binary relation is called a mapping. For the relations the postfix notation is the basic presumption (b=aρ); exceptions are relations with some long expressions in domain set or if we want to point out domain elements, and especially for mappings we use prefix notations (b=pa). We define ρ:A B, when we want to indicate that A=D(ρ) and B ⊃ (ρ), and AρB, if (a,b)εp whenever aεA and bεB. When defining mapping ρ, we also can use the notation ρ:a b, aεA and bεB. If A ⊃ B. we say that ρ is a relation in A.
[0056] Set {b:aρb} is called the ρ-class of a. Let ρ:A B be a binary relation. We say that A′( ⊂ A) is closed under ρ, if A′ρ ⊂ A′.
[0057] For set of relations we denote a ={ar:rε }, A ={ar:aεA, rε }. If ρ(A) (={ρ(a):aεA}) is B, we call ρ a surjection. If [ρ(x)=ρ(y) x=y], we call ρ injection. If ρ is surjection and injection, we say that it is bijection. If ρ(x)=x whenever xεD(ρ), we say that ρ is an identity mapping (denoted Id). The element which is an object for the application of a relation is called an applicant.
[0058] For relations ρ and σ and set of relations we define:
the catenation ρσ={(a,c):∃bε(D(σ)∩ (ρ)) (a,b)ερ, (b,c)εσ}, the inverse ρ −1 ={(b,a):(a,b)ερ}, ={ρ −1 : ρε }.
Let θ be a binary relation in set A. We say that
θ is reflexive, if (∀aεA) (a,a)εθ, θ is inversive, if θ −1 ⊂ θ, θ is transitive, if θθ ⊂ θ, θ is an equivalence relation, if it is reflexive, inversive and transitive.
For sets A and B we define
|A|=|B|, if there is such injection α that α(A)=B, |A|<|B|, if there is such injection α that α(A)⊂B, and |A|≦|B|, if |A|=|B| or |A|<|B|.
[1.1.14] We call (a,b) a tuple or an ordered pair, and in general (a 1 ,a 2 , . . . , a n ) is an n-tuple. For sets A 1 ,A 2 , . . . , A n we define the n-Cartesian power
A 1 ×A 2 × . . . ×A n ={(a 1 ,a 2 , . . . , a n ):a 1 εA 1 , a 2 εA 2 , . . . , a n εA.}.
[1.1.15] Let {A i : iε } be an indexed family, and let be the set of all the bijections joining each set in the indexed family to exactly one element in that set. Family {{r(A i ):iε }: rε } is called a generalized -Cartesian power of indexed family {A i : iε } (A i may be Ø for some indexes i) and we reserve the notation Π(A i : iε ) for it, and the elements of it are called generalized -Cartesian elements. A special example is A×Ø=A. If A=A i for each iε , we denote for the generalized -Cartesian power of set A. We denote (a 1 ,a 2 , . . . ) the elements of generalized |N-Cartesian power of indexed family A={A i : iε|N}, where a 1 εA 1 , a 2 εA 2 , . . . , and the whole set by A N . Furthermore we denote =∪( ). Any subset of a generalized -Cartesian power is called an -ary relation in the generalized -Cartesian power. is called the Cartesian number of the elements of the generalized -Cartesian power. For the number of generalized Cartesian element a we reserve the notation (ā).
[1.1.16] Let and be two arbitrary sets. We call mapping e[ ]:( Π(A i : iε )) ∪(A i : iε ) a projection mapping, where (Πjε ) projection element e[ ](j, a ) is the element in a belonging to A j , and we say that j is an arity of e[ ]. We denote simply e, if there is no danger of confusion. For elements a and b in Π(A i : iε ) a=b, if and only if e(i,ā)=e(i, b ) whenever iε . We say that a generalized Cartesian element is ≦ another generalized Cartesian element, if and only if each projection element of the former is in the set of the projection elements of the latter and the Cartesian number of the former is less than of the latter.
[1.1.17] Let Θ be a set of binary relations. Set A is Θ-ordered, if
1° A is a singleton
[0071] or 2° there is family saturating A and for each A′ε
there is set B, B≠A″, and θεΘ such that (A′×B)∩θ≠Ø.
Set A is innerly ordered, if B ⊂ A; otherwise outherly ordered. Set A is singleton ordered, if Θ is a singleton and ordinary ordered, if furthermore Θ is an equivalence relation in A. Set A is totally ordered, if ={A}, otherwise partially ordered. Finally set A is one-to-one ordered, if it is totally and innerly singleton ordered. Each set which is the image of a bijection of ordered set is ordered, too. E.g. for any set (here B)
D={A: AεP(B), for each EεP(B), E ⊂ A or A⊂E}
is ordinary ordered. |N is an ordered set. Set A is denumerable, if it is finite or there exists a bisection: |N A; otherwise it is undenumerable.
[1.1.18] Let (A i : iε ) be an indexed set. Notice that may be infinite and undenumerable. If each projection element in a generalized -Cartesian element of Π(A i : iε ) is written before or after another we will get a -catenation of family (A i : iε ) or a catenation over , and the projections of the concerning Cartesian element are called members of the catenation. Notice that also pq is a catenation, if p and q are catenations, and we say that each member of p precedes the members of q and each member of q succeeds the members of p; thus preceding and succeeding defining catenation order among the members of catenations. The member of a catenation preceding/succeeding all other members in the catenation is called the first/the last member in the catenation. A catenation having the first or the last member (the end member of the catenation) has an end. is said to be a catenation index. The set of the -catenations of A is denoted For n ε|N we define the set of the n-catenations of A, , such that = , where H={i:i≦n, iε|N}. EL(A) is the notation for the set of the elements in all catenations in set A. E.g. sequence a 1 a 2 . . . a n , nε|N, n>1, is a finite catenation. For set H of symbols we define H* (the catenation closure of H) to represent the set of all the catenations of the elements in H. Decomposition d of catenation c is any catenation of the parts of c (the elements of d) such that d=c. For our example, above, d 1 d 2 , where d 1 =a 1 a 2 . . . a , d 2 =a i+1 a i+2 . . . a n , is a decomposition of a 1 a 2 . . . a n For the catenation operation of sets we agree of the notation:
{a:aεA, * A } {b:bεB, * B }={ab:aεA, bεB, * A , * B }.
The transitive closure of set of relations is the catenation closure of including the identity mappings corresponding to the empty catenations. For set A, index set and set of relations we define:
A =(A ) , whenever iε = \i and = .
[1.1.19] Let G be a set and let A be a smallest set including G such that for set H of relations (operations) in A there is a valid equation A=∪(GH*). We say that =(A,H) is H-algebra and G is a set of its generators and A is the set of its elements. If G′ ⊂ whenever G is a generator set of , we call G′ the minimal generator set of .
[0076] P( )=(P(A),{tilde over (H)}) is the subset algebra of , where =(A,H) is an algebra, {tilde over (H)}={{tilde over (h)}: hεH} is the set of relations, where {tilde over (h)} is such a relation in P(A) that B{tilde over (h)}=Bh, whenever B ⊂ A and hεH.
[0000] [1.1.20] For any symbols x and y we define replacement x←y, which means that x is replaced with substitute y. Notation A(x←y) represents an object where each x in A is replaced with y; and A(x←Ø) is an object where x is deleted. Unr(A) means the set of such elements in A that are not replaced by anything.
1.2. Net and graph
[1.2.1] Denumerable Net
[0077] [1.2.1.1] The set of in- or outputs (forming in-/out arity alphabets [disjoined with each other] or inugle-/outglue alphabets) is a subset of an indexed set (e.g. the natural numbers) and the in-/outrank is its mightiness. The arity letters have no in- or outputs in themselves. We reserve symbols X and Y for frontier alphabets, whose letters have exactly one input and output. On the other hand symbols Σ and Ω are reserved for alphabets whose letters are not arity or frontier letters and are called ranked or elementary programme [fitting more to their practical use] letters each of which has or has not arities. Notation inp(Ξ) symbolises the set of the inarity letters of alphabet Ξ, and outp(Ξ) symbolises the set of the outarity letters of Ξ. Furthermore we denote Ψ(Ξ)=(inp(Ξ))∪(outp(Ξ)). If an arity letter is replaced we say that it is occupied. Occ(A,t) means the set of all those arities in set A of arities, which are occupied in situation net t, and Uno(A,t) are reserved for the set of all those which are unoccupied in net t; if there is no danger of confusion we may drop the situation net in the notations. L(t) symbolises the set of the letters in symbol t. If it is necessary to avoid confusion, we use notation L°(t) to indicate the set of the letters of t excluding arities, and Ψ(L°(t)) symbolizes the union of the sets of the arity letters in the elements of L°(t).
[1.2.1.2] Let A be a set and let Ξ be a set of frontier and ranked letters. For each ξεΞ we define the realization anchoring relations:
E ξ : ξ(i←a i : iεinp ξ, a i εA) A outrankξ .
Let f be a bijection joining each ξεΞ to some relation E ξ . Let Ā be the union of all Cartesian powers of set A, and we reserve that notation for it also in the following. Notation =(Ā,Ξ,f) is called a Ξ-algebra, with A as its generator set and f its binding mapping over Ξ.
[0079] We denote (i←a i : iεinp(ξ), a i εA)=ξ(i←a i : iεinp(ξ), a i εA)f(ξ).
[0080] Now for each ranked letter ξ we define operation ( -realization of ξ) as such a relation: :A inrank(ξ) A outrank(ξ)
[0000] that
ā = (i←e[inp ξ](i,ā): iεinp(ξ)), whenever āεA inrank(ξ) and for each frontier letter ξ a =a, whenever aεA.
[1.2.1.3] Now we define denumerable (ΣX-)net (DN) inductively as follows:
1° each DN has positions (possibly none) in each DN, and in those positions there can be only one DN at most, p(v 1 ,v 2 ) is denoted to be the set of the positions of DN v 2 in DN v 1 , 2° each ξεX∪Σ is a DN, and the top of ξ (top(ξ)) is ξ itself, 3° t=σ(i←({right arrow over (k)} i ,(w(s i ,n i ))), j←( k i , (w(s j ,n j ))): iε , jε ) is DN,
and the top of t (top(t)) is σ, whenever σεΣ, ⊂ inp(σ), ⊂ outp(σ), and for each i ε k i εoutp(L(w(s i ,n i ))), for each j ε k j εinp(L(w(s j ,n j ))), where w is a mapping which joins for each iε the pair of DN s i and position n i in s i to the DN having that position in s i ; correspondingly for each jε . It is defined that for each iε there is only one ( k i ,(w(s i ,n i ))) at most; correspondingly for each jε .
[0090] We say that inarity i in σ is occupied by w(s i ,n i ) in outarity k i , and outarity j in σ is occupied by w(s j ,n j ) in inarity k j . We say that position n i in t is below, specifically next below σ in t and position n j in t is above, specifically next above σ in t. The set of the positions of w(s i ,n i ) in t is defined to be the set of the positions of top(w(s i ,n i )) in t. If position p 1 in DN s is next below position p 2 in s and p 2 is below p 3 in s, we define that p 1 is below p 3 . “Above” is defined analogously. DN v 1 is below/next below DN v 2 in DN v, if a position of v 1 in v is below/next below a position of v 2 in v. “Above” is defined analogously with below. Nets v 1 and v 2 are denumerable subnets (DSN) of net v. Next below/next above is denoted shortly by and below/above is denoted by .
[0000] [1.2.1.4] We say that the set of all denumerable nets is the set of the elements of free algebra_over the minimal generator set X, denoted (X), the operations of which are called operators. The set of the elements in (X) is denoted by F Σ (X). Σ-algebra (generated by Σ) is symbolized by and F Σ is the set of that algebra (elements of which are called denumerable ground nets).
[1.2.2.] Graph
[0091] [1.2.2.01] Nets can be described by graphs, where the connections between in- and outputs of nets, that is replacements, are denoted by dendrites, and where graph actually can be seen as triple (A, ,f), where A is a set of pairs (node, its arity), is a set of dendrites, and f: αA×A is a bisection connecting the dendrites to the pairs, the arity of the first element in a pair is occupied with the node of the second element in its arity via a dendrite. In other words a dendrite connects exactly one occupied outarity to exactly one occupied inarity. The frontier and ranked letters in graphs are called nodes. See FIG. 1 . 2 . 2 . 01 of finite graph v, where the arity letters connected with dendrites are dropped from the figure. Symbol b is a ranked letter with no inputs, and x is a frontier letter. Symbols a, c, α, β, and σ are ranked letters, n i , i=1, 2, . . . , 8 are positions of nodes and e.g. p(v,α)={n 2 ,n 3 }.
[0092] If we write a graph by emitting some dendrites of it and nodes connected to them as well, we have written an incomplite image of it. A set of graphs is called a jungle.
[0000] FIG. 1 . 2 . 2 . 01 describes an example of finite graphs.
[1.2.2.02] The dendrites of graphs which are equiped with directions: from outarity to inarity, are called directioned, otherwise directionless. If all dendrites in a graph are directioned, we say the graph is directioned, otherwise it is directionless. We speak of an out-/indendrite of a node, if it is connected to out-/inarity of that node.
[1.2.2.03] If a dendrite connects outarity ν in node a to inarity μ in node b, the dendrite can be denoted by pair (a,ν),(μ,b) , and nodes a and b are called nodes of the dendrite, and the dendrite is an outdendrite of node a and an indendrite of node b. An in- and outdendrite of the same node are said to be successive to each other. The dendrites between the same two nodes are parallel with each other.
[1.2.2.04] We say that an arity which is occupied by a net is occupied via the dendrite between that arity and the net.
[1.2.2.05] Net s is said to be out-/inlinked to net t, if s has an out-/inarity of a node which is connected to an in-/outarity of a node in t with an out-/indendrite (so called out-/inlink of s). In other words: an arity of a node in one net is occupied with a node in the other net via a dendrite. If furthermore those nets have no shared nodes, we say they are neighbouring each other. A set of the neighbouring nets of a net is called a touching surrounding of the net.
[1.2.2.06] If dendrite (a,v),(μ,b) is an outlink from net s to net t, it can be denoted s(a,ν),t(μ,b) or simply s,t . A dendrite which connects two nodes in a net is an inward connection/inward link of the net. If the inward connections in a net are directed, the net is directional and if the inward connections are directionless, the net is directionless. If only a part of the inward connections are directed, the net is partly directed. The out-/indendrites of a net which are not inward connections are called out-/in-outward connections/links of the net. If a net has no outward links, it is said to be closed.
[1.2.2.07] Nets are said to be isolated from each other, if there is a net distinct from them and neighboured by them. We say that nets being neighboured by each other are linked directly, and nets being isolated from each other are linked via isolation. If the mightiness of the set of the direct links for a net is m, we speak of m-neighbouring of the net.
[0093] If nets are neighbouring each other such that they are not isolated from each other, we say they are closely neighbouring each other. See FIG. 1 . 2 . 2 . 07 . 1 , where A and B are closely neighbouring each other.
[0000] FIG. 1 . 2 . 2 . 07 . 1 is an example of closely neighbouring nets.
[0094] If nets are isolated from each other, but are not neighbouring each other, we say they are totally isolated from each other. See FIG. 1 . 2 . 2 . 07 . 2 , where A and B are totally isolated from each other.
[0000] FIG. 1 . 2 . 2 . 07 . 2 is an example of nets totally isolated from each other.
[0095] Net s is t-isolated, if the nodes of t are totally isolated from each other by the nodes of s, and inversely.
[0000] [1.2.2.08] The set of the links connecting two nets to each other is called the border between those nets. The border may be empty, too. The union of the set of the borders between a net and all other nets distinct from that net is called simply the border of the net.
[1.2.2.09] The nets which are not linked to each other are disjoined with each other. If nets have no common nodes, they are said to be distinct from each other.
[1.2.2.10] The nets of a jungle which are inlinked inside the jungle, but not outlinked, are in-end nets and at in-end positions in the jungle, and the nets outlinked inside a jungle, but not inlinked, are out-end nets and at out-end positions in the jungle. The union of the in-end nets and the out-end nets in a jungle is called the rim of the jungle.
[1.2.2.11] A denumerable route (DR) between nets are defined as follows:
1° any link between two nets is a route between those nets, and 2° if Q is a DR between net s and t and, r is a DR between t and net u, then Qr is a DR between s and u.
[0098] DR can also be seen as an inversive and transitive relation in the set of the nets, if “link” is interpreted as a binary relation in the set of the nets. Any route can also denoted by the chain of the nets linked by the dendrites in the route.
[0000] [1.2.2.12] We define an in-/out-one-way DR (in-/out-OWR) between nets as transitive relation (“link” is a binary relation) among the set of the nets as follows:
1° any link which is an in-/outlink of net s and on the other hand an out-/inlink of net t is an in-/out-OWR from s to t, and 2° if Q is an in-/out-OWR from net s to net t and r is an in-/out-OWR from t to net u, then Qr is an in-/out-OWR from s to u, and we say that s in-/out-dominates u and u out-/in-dominates s. See FIG. 1 . 2 . 2 . 12 , where x is out-dominating a,b,c,d and e but not f or g; b in-dominates only x and f.
FIG. 1 . 2 . 2 . 12 is a figure of nodes dominating others.
[1.2.2.13] An DR from a net to itself is a loop of the net, and outside loop, if furthermore in the route there is a link to outside the net; otherwise it is an inside loop of the net. The loop where each dendrite is among the links of the same jungle, is an inside loop of the jungle. Loops can be directed or directionless depending on the links in it. See FIG. 1 . 2 . 2 . 13 . 1 , where xabcd is the outside OWR-loop of x.
FIG. 1 . 2 . 2 . 13 . 1 is an example of OWR-loop.
A bush is a jungle which has no inside loops. FIG. 1 . 2 . 2 . 13 . 2 of a bush. A bush is called elementary, if it has no parallel dendrites.
FIG. 1 . 2 . 2 . 13 . 2 describes a bush.
[1.2.2.14] If A is the set of routes between nets s and t, we say that s and t are A- or |A|-routed with each other.
[1.2.3] Generalized Net
[0101] [1.2.3.1] A set of denumerable nets is generalized net (GN) (simply net in the following, if there is no danger of confusion), and unbroken, if each net of that set, except the ones in a rim of the set which are only inlinked, is outlinked to some other net or nets in that set; otherwise it is broken. If none node of that set is neighbouring with any other, we say that the GN is totally broken. E.g. any set, the elements of which seen as nodes, can be seen as a totally broken GN and is called degenerated. Notice that an unbroken generalized net is one-to-one ordered. An unbroken net where each node is connected to exactly one node is a chain.
[1.2.3.2] Nets are defined to be the same, if they have the same graph to describe them, and on the other hand in that case they can be seen as representatives of the graph. In the following we use without any special remarks terms “net” and “graph” in the same meaning and do not specify alphabets in graphs, if there is no danger of confusion. Otherwise the graph for net t is notated by g(t) and the set of the representatives for graph v is denoted by (v). A set of GN:es is called a jungle.
[1.2.3.3] The set of the positions of a GN consists of the positions of the DN:es of the GN. Let P 1 and P 2 be two arbitrary sets of positions. We define and denote that P 1 P 2 , if P 1 and P 2 are separate and ∀p 1 εP 1 ∃ p 2 ε P 2 such that p 1 p 2 , and P 1 P 2 , if ∀p 1 εP 1 p 1 p 2 whenever p 2 εP 2 .
[1.2.3.4] Let s and t be two arbitrary GN:es. If for each denumerable net of s, there is such a DN of t, that the former is a DSN of the latter, we say that s is a generalized subnet (GSN) of t. The set of the graphs of jungle T of nets is denoted by g(T). The jungle of the subnets of all nets in jungle T is denoted sub(T). Notice that each nonsingleton jungle can be seen as a broken GN. A set of subnets of the nets in jungle T is called a subjungle of T.
[1.2.3.5] For net v, v|p (an occurrence), is denoted to be the subnet of v having or “topped at” position p in v. The set of all subnets in v is denoted by sub(v). Subnets which are letters are called leaves, and the set of all leaves in v is denoted by Leav(v). For net v we denote fron(v) as the frontier letters of v, and rank(v) is the set of all ranked letters in v. A down-/up-fntier net of DN v, down-/up-fronnet(v), is such a denumerable subnet of v, whose occurrence is next below/next above v (at so called down-/up-fiontierposition of v). We denote Frd(v) meaning the set of all down-frontier nets of v, and Fru(v) is the set of all up-frontier nets of v, and F r (v) means the set of all frontier nets of v.
[1.2.3.6] We define the height of net t, hg(t), by the following induction:
1° hg(t)=0, if t is a frontier or ranked letter 2° hg(t)=1+max{hg(s):sεF r (t)}, if t is not a frontier or ranked letter.
[1.2.3.7] The set of all positions of subnet t in jungle T is denoted by p(T,t). The set of the positions in jungle T is denoted p(T). For an arbitrary net t the positions of the outside arities of t, (OS(t)), means the set of the positions of all those arities of the elements in L(t) which are not occupied by anything in that particular net t. Furthermore for t we define in/-outdegee (δ in (t)/δ out (t)) as the mightiness of the set of the in-/outarities in all nodes of t.
[1.2.3.8] We say that net is finite, if the number of denumerable nets and frontier and ranked letters in it are finite number. The set of all GN:es is denoted by G(Σ,X), if the set of its DN:es is F Σ (X). Notice that studying infinitenesses the crucial thing is ordering and there are nets the most valuable tools.
[1.2.3.9] A net is said to be k-successive, if it can be devided in k totally broken nets by a border. A chain with k nodes is k-successive.
[1.2.4] Realization of Net
[0104] [1.2.4.1] Let be a Ξ-algebra with A being the set of its elements and Ξ=X∪Σ. Let t be defined as in the DN-definition. Then we define the -realization of t (denoted ( )), where is a relation in Ā, the -operation of t, fulfilling set of conditional demands C , and for each aεĀ (ā)=w(s j ,n j ( k j ←e(j, (i←e( k i ,w(s i ,n i (ā)):iε )):jε( ), if t∉toy.
[0105] Notice that Ā={ (ā):tεF Σ , āεĀ} and (Ā,{ tεF Σ }) is { tεF Σ }-algebra. If we chose f(σ) to be an identity mapping for each σεΣ and A=X we shall get a free Σ-algebra over X. (X)-realization is -realization, where A=F Σ (X).
[0106] Images of realizations of DN:es can be seen as outrank dimensional objects compounding dimensions being images of realizations of trees (DN:es with only one output) which on their side are inrank dimensional with dimensions being images of realizations of strings (trees with only one input). We call sets of trees forests. The realizations of the trees are mappings.
[0107] Tuple ( ,C ) is the -realization of GN, G , t, where is obtained by replacing each DN in t with the -operation of the concerning DN. Net t is called the carrying net for ( ) and the set of -realizations of the nodes of t is entitled -nest of t or the nest of , and we say that t and are beyond D whenever D is a subset of that nest; we denote G (|D). For each A o ⊂ Āwe define A o ( )=A o , and call A o ( ) a ( )-transformation of A o . For jungle T we denote ( )={t( ):tεT}. Important examples of realizations are equations, where e.g. symbol “=” is the realization of a ranked letter with two inputs.
[0000] [1.2.4.2] Lemma 1.2.1. Each demand or claim can always be presented with realizations of nets.
Proof. Each presentable elementary claim is actually a relation in some algebra. □
[1.2.4.3] Lemma 1.2.2. Any realization of any GN can be presented as a graph.
Proof. Straightforward. □
[1.2.4.4] Let be an -realization for algebra . Two nets are -confluent with each other in regard to a relation between them, if their -transformations are in that relation with each other.
[1.2.4.5] Let A be a jungle and =(Ā,Ξ,f) be a Ξ-algebra. Let p, r 1 , r 2 , r 3 , s 1 , s 2 , t 1 and t 2 be nets in A, and let R, S and T be -realizations of some suitable nets of A. Now we are defining for only descriptive use some special nets by visible manner and example wise: FIG. 1 . 2 . 4 . 5 . 1 of transformator graph (TG) over {R,S,T} (a set of node transformators), denoted TG({R,S,T}). If H is a set of realizations, set K being one of the subsets of H, we say that is beyond K whenever is TG(H) and we denote TG(|K).
FIG. 1 . 2 . 4 . 5 . 1 describes a transformator graph over a set of realizations.
FIG. 1 . 2 . 4 . 5 . 2 of a realization process graph (RPG) of , where pT=(t 1 ,t 2 ), (r 3 ,t 1 )S=(s 1 ,s 2 ) and (s 2 ,t 2 )R=(r 1 ,r 2 ,r 3 ).
FIG. 1 . 2 . 4 . 5 . 2 is the figure of a realization process graph of the transformator graph in FIG. 1 . 2 . 4 . 5 . 1 .
Generally speaking: any RPG is a TG-associated net, where each net as a node (an element of a transformation) in the RPG is in- and up-connected to at most one -realization in the TG. FIG. 1 . 2 . 4 . 5 . 3 of a transformation graph (TFG) of .
FIG. 1 . 2 . 4 . 5 . 3 is an example of a transformation graph of the transformator graph in FIG. 1 . 2 . 4 . 5 . 1 .
1.3. Substitution and enclosement
[1.3.01] Let T be an arbitrary jungle. Notation T(P A:*) is the jungle which is obtained by replacing (considering conditions *) all the subnets of each net t in T, having the position in set P, by each of elements in set A. If each position of set S of subnets of each net t in T is wished to replace by each of elements in A, we write simply T(S←A).
[1.3.02] Suppose we have a monadic mapping that is any mapping λ:Σ P(F Ω ). Let be a Ω-algebra with A being the set of its elements. Then the morphism {tilde over (λ)}: (X) is the mapping defined such that
{tilde over (λ)}(x)εA for each xεX, 2° if t is as in the DN-definition, then
{tilde over (λ)}(t)=∪({tilde over (λ)}w(s j ,n j ))( k j ←e(j, (i←e( k i ,{tilde over (λ)}(w(s i ,n i ))):i ε ∩Uno(inp(L(r))))):
jε ∩Uno(outp(L(r)))):rελ(σ)).
[1.3.03] Let and be two Σ-algebras, A being the set of the elements of and B being the set of the elements of . Because (X) is a free algebra, we can choose such two monadic mappings f and g and morphism f and g that
f(σ)=g(σ)=σ for each σεΣ and {tilde over (f)}(F Σ (X))=A and {tilde over (g)}(F 93 (X))=B.
[0113] Thus homomorphism h: is such a mapping that for each denumerable ΣX-net t
h({tilde over (f)}(t))={tilde over (g)}(t).
If α:A B is such a mapping that a({tilde over (f)}(x))={tilde over (g)}(x) for each xεX, we say that h is an extension of α to a homomorphism: symbolized by {circumflex over (α)}. Homomorphism {circumflex over (α)} is a denumerable substitution, if furthermore {tilde over (f)}(x)=x, whenever xεX. Later when rewriting DN:es we deal with the substitution defined in (X). Let k:x (i,s) be a mapping where xεX, s is a GN and iεΨ(L(s)). Thus mapping {circumflex over (k)}in the set of the nets is generalized net substitution (shortly substitution, if there is no danger of confusion), if for each net t
{circumflex over (k)}(t)=t(x←k(x): xεfron(t)).
Notice that the denumerable substitutions in (X) can be seen as special cases of generalized net substitutions.
[1.3.04] Let P and T be arbitrary jungles. If S is a catenation of substitutions such that T=S(P), we say that there is a S-substitution route between P and T.
[1.3.05] Net u is a context of net t, if t=u(i←(k i ,s i ): k i εΨ(L(s i )), s i εS, iεΨT(L(u))) for jungle S of subnets of t; u can also be expressed with notation con P (t), where P is the set of the positions of the substitutes of S in t. Notation con(T) means the set of all contexts of jungle T. We also call u the abover of nets s i in t, denoted t\ b s i , and each s i is a belower of u in t, denoted t\ a u.
[0116] If s is a subnet of net t, we say that t can be devided in two nets: s and the abover of s in t.
[0000] [1.3.06] Net t is an instance of net s, if t=f(s) for some substitution f. Context con P (t) is the apex of s by f in regard to t, if P is the set of positions where substitution f takes places in s. See FIG. 1 . 3 . 06 , where x 1 , x 2 , y 1 and y 2 are frontier letters and so is an apex of s (in regard to s).
FIG. 1 . 3 . 06 clarifies an apex of a net.
[1.3.07] Contexts of subnets in t are enclosements of t. Net s whose apex by substitution f is an enclosement of t is said to match t by f in the positions of g(s) in t. If net s matches net t, we say that the arities in set OS(s)\OS(t) are the matching arities of s in t.
[0117] Notice that even if a net itself is unbroken, an enclosement of it may be broken. See FIG. 1 . 3 . 07 .
[0000] FIG. 1 . 3 . 07 is a figure of a broken enclosement of an unbroken net.
[0118] Graph u is an enclosement of graph v, if v=u(i←(k i ,s i ): k i εΨ(L(s i )), s i εS, iεΨ(L(u))) for jungle S.
[0119] The set of all enclosements of the nets in jungle T is denoted enc(T).
[0120] Notice that the positions of an enclosement of a net are the positions of the tops of the enclosement in that net. For jungle T and S we denote p(T,S)=∪(p(t,s): tεT, s ε S∩enc(T)). Notice that nets s and t are the same, iff enc(s)=enc(t).
[0000] [1.3.08] The overlapping of nets is the maximal element in the intersection of the sets of the enclosements of those nets. If the overlapping is not empty, the nets overlap each other. We denote the overlapping of jungle S with notation S, and the overlapping of nets sand t with s t. Furthermore for any jungle S and T we denote S T={s t: tεT, SεS}. The omission of two nets s and t, denoted s t, is the union (s\ b (s t))∪(s\ a (s t)); notice that one of the two sets to be united is always empty, which one depends on weather s t is the abover or the belower of s. For arbitrary net s and jungle S we denote s T=∩(s t:tεT) and for jungles S and T we use notation S−T={s T:SεS}. For an arbitrary nets s and t the positions of the outside arities of t in s, (OS(t,s)), means the set of the positions of all those arities of the elements in L(t s) which are not occupied by anything in net s.
[1.3.09] For jungle T a type ρ of net (e.g. a tree) being in enc(T) is a maximal ρ-type net in enc(T), if it is not an enclosement of any other p-type net in enc(T) than itself. The other p-type nets in enc(T) are genuine.
[1.3.10] A set of nets is said to be a cover of net t, if each node of t is in a net of the set. See FIG. 1 . 3 . 10 . We denote the set of all covers of net t with Cov(t).
FIG. 1 . 3 . 10 describes a cover of a net.
[1.3.11] Cover A saturates net t, if A ⊂ enc(t). We denote the set of all saturating covers of net t with Sat(t). See FIG. 1 . 3 . 11 . 1 .
FIG. 1 . 3 . 11 . 1 is a figure of a saturating cover.
E.g. a saturating cover of net t is natural, if each net in the cover is maximal tree of t. See FIG. 1 . 3 . 11 . 2 .
FIG. 1 . 3 . 11 . 2 is an example of a natural cover.
[1.3.12] A saturating cover of net t is a partition of t, if each node of t is exactly in one net in the cover. We reserve notation Par(t) as for the set of all partitions of net t For an arbitrary jungle A we define the partition induced by jungle A (denoted PI(A))={( A′ { A″:A′⊂A″, A″εP(A)}:A′εP(A)}. We can write the following clause:
[1.3.13] Clause. “A correlation between partitions and covers of nets”.
For any net s
[0121] EεCOV(s), if and only if PI(E) sεPar(s).
[0000] Notice that if A is a saturating cover of net t, then PI(A) is a partition of t. See FIG. 1 . 3 . 12 .
FIG. 1 . 3 . 12 describes a partition of a net.
1.4. Rewrite
[0122] [1.4.1] A rewrite rule is a set (possibly conditional) of ordered ‘net-jungle’-pairs (s,T) denoted often by s→T (which can be seen as nets if we keep “→” as a ranked letter); s is called the left side of pair (s,T) and T is the right side of it. We agree that right(R) is the set of all right sides of pairs in each element of set R of rewrite rules; left(R) is defined accordingly to right(R). The frontier letters of nets in those pairs are called manoeuvre letters).
[0123] A rule is said to be simultaneous, if it is not a singleton. The inverse rule of rule φ, φ −1 , is the set {(t,s):tεT, (s,T)εφ}. A rule is single, if it is singleton and the right side of its pair is also singleton.
[0000] [1.4.2] A rule is an identity rule, if the left side is the same as the right side in each pair of the rule. A rule is called monadic if there is a monadic mapping connecting the left side to the right side in each pair of the rule. If for each pair r in rule φ, hg(left(r))>hg(right(r)), we call φ height diminishing, and if hg(left(r)<hg(right(r)), φ is height increasing, if hg(left(r))=hg(right(r)), we call φ height saving.
[1.4.3] A rule is alphabetically diminishing if for each pair r in the rule there is in force: (i) right(r) is a frontier or ranked letter or (ii) hg(left(r))=2, top(right(r)) ε L(left(r)) and right(r) is a minimal rewritten net, meaning that its genuine subnets are all in a manoeuvre alphabet.
[1.4.4] Any rule and the concerning pairs in it are said to be
1° manoeuvre increasing if for each of its pairs, r, fron(left(r))⊂fron(right(r)), and
2° manoeuvre deleting if for each of its pairs, r, fron(left(r))⊃fron(right(r)), and
3° manoeuvre saving if for each of its pairs, r, fron(left(r))=fron(right(r)), and
4° maneuver mightiness saving, if for each of its pairs, r,
|p(left(r),x)|=|p(right(r),x)|, whenever x is a manoeuvre letter, and
5° maneuver mightiness decreasing, if for each of its pairs, r,
|{p(left(r),x): x is a manoeuvre letter}|⊃|{p(right(r),x): x is a manoeuvre letter}|, and
6° arity increasing if for each of its pairs, r, OS(left(r))⊂OS(right(r)), and
7° arity deleting if for each of its pairs, r, OS(left(r))⊃OS(right(r)), and
8° arity saving if for each of its pairs, r, OS(left(r))=OS(right(r)), and
9° arity mightiness saving, if for each of its pairs, r,
|p(left(r),ξ)|=|p(right(r),ξ)|, whenever ξ is an unoccupied arity letter, and
10° letter increasing if for each of its pairs, r, L(apex(left(r)))⊂L(apex(right(r))), and
11° letter deleting if for each of its pairs, r, L(apex(left(r)))⊃L(apex(right(r))), and
12° letter saving if for each of its pairs, r, L(apex(left(r)))=L(apex(right(r))), and
13° letter mightiness increasing if for at least one of its pairs, r,
|∪(p(apex(left(r)),z): z is a frontier or ranked letter)|<|∪(p(apex(right(r)),z): z is a frontier or ranked letter)|.
[1.4.5] Rule φ is left linear, if for each r ε φ and manoeuvre letter x there is in force |p(left(r),x)|=1, and right linear, if |p(right(r),x)|=1. A rule is totally linear, if it is both left and right linear.
[1.4.6] A set consisting of rewrite rules and of conditional demands (possibly none) (for the set of which reserved symbol ) to apply those rules (e.g. concerning application orders or the objects to be applied (desired substitutions or the positions where applications are wanted to be seen to happen)) is called a renetting system RNS, and a Σ-RNS, if its rewrite rules consist exclusively of pairs of ΣX-nets. Notice that rules in RNS:es can be presented also barely type wise: nets in pairs of rules in RNS:es are allowed to be defined exclusively in accordance with the amount of the arities or nodes possessed by them.
[1.4.7] A RNS is finite, if the number of rules and in it is finite. A RNS is said to be limited, if each rule of it is finite and in each pair of each rule the right side is finite and the heights of both sides are finite. For the clarification we may use notation instead of for RNS A RNS is conditional (or sensitive), contradicted nonconditional or free, if its is not empty. A RNS is simultaneous, contradicted nonsimultaneous, if it has a simultaneous rule.
[1.4.8] A RNS is elementary, if for each pair r in each rule of the RNS is monadic or alphabetically diminishing. If each of the rules in a RNS is of the same type, the RNS is said to be the type, too. For each RNS we denote = (φ−φ −1 ).
1.5. Application and Transducers
[0128] [1.5.01] For given RNS , jungle S is -rewritten to jungle T, and is reduced under or by rule φ of , and is said to be a rewrite object for or so, denoted
S→ T (called -application) or T=Sφ,
if the following “rewrite” is fulfilled:
T=∪(S(p {tilde over (f)}(right(r))): left(r) matches s in p by some substitutions f and {tilde over (f)}, rεφ, sεS, pεp(S), )), where {tilde over (f)} is specified in and if it is not specified we suppose {tilde over (f)}=f. Notice that T=S, if any left side in any pair in p does not match any net in S. We say that S is a root of T in and T is a result of S in . See FIG. 1 . 5 . 01 , where h, an enclosement of s, is the apex of k, and x 1 , x 2 , x 3 are frontier letters.
FIG. 1 . 5 . 01 describes an enclosement of a net, where rewrite takes a place in that net.
[1.5.02] The enclosements at which rewrites can take places (the sets of the apexes of the left sides in the pairs of the rules in RNS:es) are called the redexes of the conserning rules or RNS:es in the rewritten objects. For RNS and jungle S we denote
[0130] S =∪(Sφ:φε ).
[0000] Rule φ of is said to be applied to jungle S, if for each sεS s has φ-redexes (redexes of φ in s) fulfilling and thus φ is applicable to S and S is φ-applicable or φ-rewritable. RNS is applicable to S and S is -applicable or -rewritable, if contains a rule applicable to jungle S.
FIG. 1 . 5 . 02 . 1 illustrates an example of an application of manoeuvre mightiness increasing rule and on the other hand an example of an application of manoeuvre letter increasing conditional rule. In the figures a, b, α, and β are nets and x, y and z are frontier letters.
[1.5.03] Lemma 1.5.1. Any relation can be presented with a RNS and its rewrite objects. On the other hand with any given RNS and jungle we are able to construct a relation.
Proof. Let r be a relation. Constructing RNS ={a→b: (a,b)εr} we obtain
r={(a,a(a→b)):a→b ε }.
On the other hand for any RNS and jungle S
{(s,sφ):sεS, φε }
is a relation. □
[1.5.04] Derivation in set of RNS.es is any catenation of applications of RNS:es in such that the result of the former part is the object of the latter part of the consecutive elements in the catenation, and the results in the elements in the catenation are called -derivatives of the object in the first element, and the catenation of the corresponding rules is entitled deriving sequence in , for which we use the postfix notation. We agree that for any deriving sequence and any jungle S
=(S , if = .
[1.5.05] Let A be a jungle, t a net in A, Ξ a set of frontier and ranked letters, =(Ā,Ξ,f) a—Ξ-algebra, , a set of conditional demands and for each ranked letter ξεΞ realization anchoring relation f(ξ) is defined as follows:
f(ξ):ξ(i→a i : iεinpξ, a i εA) ({a i : iεinpξ,a i εA}(ξ)) outrankξ ,
where k, an attaching mapping, is a mapping joining each ξ to a set of RNS:es. Thus -realization of net t, ( ), is a t-transducer (TD) over set ∪k(Ξ) of RNS:es, and an interaction between those RNS:es.
[0135] C , can e.g. be the following:
For some φεenc(t) ã =ã, whenever ãε where =Uno(Ψ(L((φ))), if for subnet φ′ of φ (top((φ′) does not match ã for some νε fronnet(φ′). That demand means that the realizations of each node in some enclosement of t has to match the substitutes in the replacements of the inputs in each node in -operation of that enclosement, if is to be applicated.
For the clarification we may use notation C instead of C for TD
[0137] Notice, that RNS:es are special cases of transducers as well as semantic networks and symbol compinations and clauses of predicate, mathematical or formal logic represented as RNS:es (lemma 1.5.1) are examples of widely occurring type of elementary TD:es.
[0138] Let be an arbitrary set, and for each iε let be a TD, thus we denote =Π({ }:iε ), and ā =Π(e(i,ā) iε ), whenever ā is a Cartesian element. For any applicant S S is called the result of S in .
[0000] [1.5.06] Lemma 1.5.2. The conditional demands can be presented as a TD having no demands, and thus any TD, let us say , can be given as a TD with no demands and the carrying net having the carrying net of in its enclosements.
Proof. The claim is following from lemmas 1.2.1 and 1.5.1. □
[1.5.07] If each RNS in a TD is of the same type (e.g. manoeuvre saving), we say that the TD is of the type. A TD is said to be altering, if while applying it is changing, e.g. the number of the rules in its RNS:es is changing (thus being rule number altering. A TD is entitled contents expanding, if some of its RNS:es contain a letter mightiness increasing rule. A TD is called trivial, if each applicant is the same as the result in the TD.
[1.5.08] A TD is a transducer graph (TDG) over a set of transducers, if the set of the carrying nets of all transducers in the set is a partition of the carrying net of the TD. The transducer graph over set T is denoted TDG(T), and any TDG(T) is said to be beyond each subset of T, denoted in the same way as for TG concerning that subject.
[0139] A TDG is entitled direct (in contradiction to indirect in other cases), if the only demands for the TDG are those of the TD:es in the TDG.
[0140] Any TDG over a set can be visualized as a TG over the same set.
[0000] [1.5.09] Lemma 1.5.3. The carrying net of any altering TD can be seen as an enclosement of the larger carrying net of some nonaltering TD.
Proof. Straightforwardly from lemma 1.5.2 □
[1.5.10] For TD we define relation → (called transformator) in G(Σ,X) ≦inp(X) such that
→ ={(ā, x←[inp(X)](i,ā):iεinp(x), xεX)): āεG(Σ,X) ≦inp(X) }.
[1.5.11] For any transducers and we define = if → =→ is, is the notation for the set of all derivations in is applicable to jungle S and S is -applicable, if is φ-rewritable, whenever φ is a deriving sequence in If a jungle is not applicable, it is entitled -irreducible or in normal form under . For the set of all -irreducible nets we reserve the notation IRR . For each jungle S and TD we denote the following:
[0142] *|S is the set of the elements in * applicable to S,
[0143] S =S{→ }*∪IRR
[0144] |S={r:rε *|S, Sr ⊂ S )}.
1.6. Equations and Decompositions
[0145] [1.6.1] Let and be two TD:es. Let H be a list of symbols in and where ={=,ε,⊂, ⊂ }. If (→ ) (→ ) for some substitutes of H, we call (H) a RNS-equation (RE) and those substitutes are its solutions.
[0146] RNS-equations cover also the ‘ordinary’ equations (with no RNS:es), being due to lemma 1.5.1, because we can chose such TD:es to represent equations that the carrying nets of those TD:es contain frontier letters, and RNS:es in the TD:es have rules the right sides of which contain the same realizations of the same carrying net as in the ordinary equations.
[0000] [1.6.2] Subset P of enc( ) is called a factor in RNS-equation (H); a left handed factor, if P ⊂ enc ), and a right handed factor, if P ⊂ enc( ) . (H) is of first order in respect to an element of H, if the element exists only once in the equation.
[1.6.3] Let K be a factor in RNS-equation (H). We say that the RE is a representation of K; specifically an elicit one (in contradiction to implicit in other cases), if K= and K ⊂ enc( ). The right handed factors are decomposers of K and is a decomposition for K, if (H) is an explicit representation of K and is =. A decomposition of K is said to be linear/unlinear, if it is a direct/an indirect TDG.
§ 2. Inventiveness
[0147] [2.1] Recognizers and languages
[2.1.1] Let A and B be sets and let α: A B be a binary relation. Let A′ be a subset of B. We define recognizer such that =(α,A′). Jungle S (probed object) is said to be recognized by recognizer , if SαεA′. E.g. “validity of inference”: RNS-equations for combinations of elementary logical relations being probed objects a is “true value surjection morphism” from {g:g is a TFG of h, hεTG} to true values, A′ representing value “true”. Language is the set of the elements recognized by . Notice that, if α is the identity mapping in the set of elements, there is a valid equation A′= meaning that recognizer (α,A′) separates from arbitrary set of elements those ones, which have property A′. Observe also that a can be a TD-transformator providing very wide variety of use.
[2.1.2] Let be an arbitrary set and for each i,jε let A i be a set and θ ij : A i A j a binary relation. Let Ā( )=Π(A i : iε ) and {tilde over (θ)}=∇(θ ij : (i,j)ε ) for some . Let α:Ā( ) Π(θ ij : (ij)ε ) be a binary relation, where āα=Π(θ ij : (i,j)ε e(i,ā) θ ij e(j,ā)), whenever āεĀ( ). The language recognized by =(α,{tilde over (θ)}) is {tilde over (θ)}-associated over (denoted ); if in {tilde over (θ)} each θ ij =θ, we speak of θ-associated language.
[0148] Notice that θ-associated language over a singleton is θ-relation itself, if =2. Furthermore it is noticeable that a set consisting of the projections in an element of θ-associated language is an equivalence class of θ-relation, if θ is an equivalence relation. Inversely to the above: a set of elements, the projections of the elements figure a θ-equivalence class, is θ-associated language.
[0000] [2.2] Problem and solution
[2.2.1] Problem is a triple (S, ), where the subject of the problem S is a jungle called the mother graph, is a recognizer and limit demands (denoted as independent) is a sample of demands conserning solutions of the problem . TD is a presolution of problem , if S ε thus S being called a solution product, and if furthermore fulfils the demands in set , is a solution of E.g. solution can be a system, by which from certain circumstances S, can be built with some limit demands (e.g. the number of the steps in the process) surrounding S which in certain state α(S ) (for morphism a) has a capacity of A′-type.
[2.2.2] We can describe a solution for a problem as wandering in a net:
[0149] 1. The start from a given node (mother graph) of the TFG
[0150] 2. to the right node (solution product) (ε ) of the TFG
[0151] 3. via the right route in the TDG (solution) (fulfils limit demands).
§ 3. Parallel Process and Abstract Algebras (for Automated Problem Solving)
3.1. Partition RNS and Abstraction Relation
[0152] [3.1.1] For each net (here c) we define a partition RNS (PRNS) (here ) of that net as a RNS fulfilling conditions (i)-(iii):
(i) is manoeuvre mightiness and arity mightiness saving
(ii) 1. {apex(left(φ)): φε } is a partition of net c
[0153] or 2. ⊃ {L(c)∩L(c )=Ø}
[0000] (iii) apex(right(φ)) is a letter outside set L(c) whenever φε , and {(left(φ),right(φ)): φε } is an injection.
[0154] We say that c is -partition result for c. Observe that for each PRNS there may be several nets, the PRNS:es of which that RNS is an example of. Those nets have apexes of left sides of rules in the RNS in different positions.
[0000] [3.1.2] Lemma 3.1. For each net c and each PRNS
[0155] c ̂=c
[0000] Proof. Straightforward. □
[3.1.3] If for nets s and t and PRNS there is an equation s =t, we say that s is a substance of t in , and t is a concept of s in .
In the following presented “abstraction relation” is needed in process to refere to a common origin for partitions of subjects in problems to be solved and known ones.
[3.1.4] The abstraction relation (AR) is such a binary relation of the pairs of nets, where for each pair (here (s,t)) there is such net c and PRNS:es and , that
c =s and c =t.
Nets s and t are said to be abstract sisters with each other.
[3.1.5] Let θ be a relation in a set of nets, and let (s,t) be an element in that relation. If (sφ,tφ)εθ, whenever φ is a manoeuvre mightiness and arity mightiness saving renetting rule which has a redex in s and t, we say that s and t are θ-congruent with each other, and if the elements in each pair of θ are θ-congruent, we call θ a congruent relation. If a relation is both an equivalence and congruent relation, it is entitled a congruence relation.
[3.1.6] The construction for a common substance of two nets given in the proof of the following characterization theorem 3.1 is the only possible one of those most wide range models.
“A characterization of the abstraction relation”—Theorem 3.1. Let θ be the abstraction relation, and a and b be two nets. Thus
a θ b |OS(a)|=|OS(b)|.
Proof.
[0158] Let A 1 ∪A 2 be a partition of net a, and let B 1 ∪B 2 ∪B 3 be a partition of net b. The conserning partitions may exclusively consist of letters in net a and b. We can construate substance c for a and b as in the following figures, distinguished in two different cases.
[0159] For border in the partition of net a and borders and in the partition of net b it is to be constructed net c and partitions for it, where
(i) A′-partition: A 1 ′∪A 2 ′, where |A 1 ′|≧|A 1 |, |A 2 ′|≧|A 2 |, and there is bijection f a : A 1 ′∪A 2 ′ A 1 ∪A 2 such that |L(a′)|≧|L(f a (a′))| whenever a′εA 1 ′∪A 2 ′, and (ii) B′-partition: B 1 ′∪B 2 ′∪B 3 ′, where |B 1 ′|≧|B 1 |, |B 2 ′|≧|B 2 | and |B 3 ′|≧|B 3 |, and there is bijection f b : B 1 ′∪B 2 ′∪B 3 ′ B 1 ∪B 2 ∪B 3 such that |L(b′)|≧|L(f b (b′))| whenever b′εB 1 ′∪B 2 ′∪B 3 ′, and (iii) border “inside nets in B 2 ′ “and borders and ” inside nets in A′-partitions “fulfil the equations: | |=| , | |=| |,| =| |, and (iv) Λ 1 and Λ 2 are sets of outside arities.
[0164] Straightforwardly we thus can construct PRNS:es a and b of net c such that A 1 ′ =A 1 ,A 2 ′ =A 2 , B 1 ′ =B 1 , B 2 ′ =B 2 and B 3 ′ =B 3 .
[0000] Case 1° The outside arities are in neighbouring elements in a partition of net b. See FIG. 3 . 1 . 6 . 1 .
FIG. 3 . 1 . 6 . 1 is the description for the proof of “a characterization of the abstraction relation”-theorem 3.1 in the case where the outside arities in the other concept are in neighbouring elements of a partition.
[0165] Case 2° The outside arities are in such elements of a partition of net b which are totally isolated from each other. See FIG. 3 . 1 . 6 . 2 .
[0000] FIG. 3 . 1 . 6 . 2 is the description for the proof of “a characterization of the abstraction relation”-theorem 3.1 in the case where the outside arities in the other concept are in elements of a partition totally isolated from each other.
Proof. :
[0166] Let |OS(a)|≠|OS(b)|. If c is a substance for net a, we have |OS(c)|=|OS(a)|, because the PRNS between a and c is arity mightiness saving, and from the same reason we are not able to get any concept to c with the mightiness of the outside arities differing from the one of c. Therefore (a,b)∉θ.□
[3.1.7] Corollary 3.1. Any substance and any of its concepts are in the abstraction relation with each other.
Proof. Any substance and its concepts have the same amount of outside arities, because interacting PRNS:es are arity mightiness saving. □
[3.1.8] Corollary 3.2. The abstraction relation is a congruence relation.
Proof. Let a and b be two nets in the abstraction relation θ with each other. Let φ be a manoeuvre mightiness and arity mightiness saving rule which has a redex both in a and b. Theorem 3.1 yields |OS(a)|=|OS(b)|, and therefore θ is an equivalence relation. In accordance with the definition of our φ we have |OS(aφ)|=|OS(bφ)|, and therefore we obtain aφθbφ from theorem 3.1 yielding θ is congruent. □
[3.1.9] Any class of the abstraction relation is formed by transformation graphs outdominated (‘centered’) by substances (FIG. 3 . 1 . 9 . 2 ): incomplite images of ‘minimal’ realization process graphs of a TG over a set of TD:es (FIG. 3 . 1 . 9 . 1 ) in the class. In the figures c 1 , c 2 and c 3 are substances and and are TD:es.
FIG. 3 . 1 . 9 . 2 describes forming a class of the abstraction relation by transformation graphs outdominated (‘centered’) by substances.
FIG. 3 . 1 . 9 . 1 describes incomplite images of ‘minimal’ realization process graphs of a TG over a set of TD:es in the class of the abstraction relation.
3.2. Altering RNS
[0167] “Macros” treated in this chapter are needed in process to get solutions for elements in the subject of the problem in study via known solutions in memories for problems with e.g. another elements in the subjects.
[0000] [3.2.1] “Altering macro RNS”-theorem 3.2.1. For each PRNS and each RNS there is RNS and PRNS such that there is in force an implicit equation of first order for unknown , where is a decomposer of a linear decomposition for : =
Proof. Let {tilde over (d)} symbolies the apex off d whenever d is a net.
1° Let be a PRNS. 2° Let an arbitrary RNS and let set { (φ):φε : be a family of distinct sets, and for each rule φ in
(i) φ={a i →B i : iε (φ)}, and (ii) Let be such a subset of (φ) that D∩E=Ø, where
D=∪enc{apex(a i ):iε }, and E=∪enc{apex(b): bεB i , iε (φ)}∪enc{apex(left(r)): rεφ,apex(left(r))∉apex(L(right( ))( )̂)}, and
(iii) Let φ)= (φ)\ . For each (k,j)ε (φ)× (φ) and each b k εB k let {tilde over (s)} bkj be the maximal nonempty element of intersection enc(apex(a j ))∩enc(apex(b k )), and the apex of net s bkj . Furthermore let b k ′ and a j ′ be such nets that s bkj is the abover of b k ′in b k and the abover of a j ′ in a j .
3° Let us now construct required a rule number altering macro RNS for in regard to , (thus being one of its micro RNS.es). For each iε (φ) and each φε let be a set of such nets that there exists PRNS for which b i →f i (b i )ε= for bisection f i : B i → , whenever b i εB i (notice that is straightforwardly to be constructed).
[0175] Furthermore let g be a bisection with left(∪( ) as its domain set such that g(a)εa ̂, whenever ã ε apex(L(right( ))( )̂∩apex(left(∪ ))).
[0176] Let σ bkj be such a net that its apex is a letter (∉L( ∪ )) for which |OS({tilde over (σ)} bkj )|=|OS({tilde over (s)} bkj )|, and in addition let nets β k ′, θ k and α j ′ be such that σ bkj is the abover of β k ′in η k and α j ′ in g(a i ), where |OS({tilde over (β)} k ′)|=|OS({tilde over (b)} k ′)|, |OS(ā j ′)|=|OS(ā j ′)|, and for each manoeuvre letter x
[0177] |p((η k ),x)|=|p((f k (b k )),x)| and |p(g(a j ),x)|=|p(a j ,x)|.
[0178] In addition let = ((a i ←g(a i )),(b i ←f i (b i )): iε (φ), b i εB i , φε ) be the set of conditional demands for our macro.
[0179] Now ={g(a i )→ , f k (b k )→η k : iε (φ), kε (φ)), b k εB k , φε }, because thus there can be constructed an interacting PRNS between each simultaneous phase of processes and ; (even in the case where applicants for and are not unbroken and is manoeuvre deleting). □
[0000] See FIG. 3 . 2 . 1 , where β k =f k (b k ) and β j =f j (b j ), and α k =g(a k ) and α j =g(a j ), R is a rewrite object.
FIG. 3 . 2 . 1 describes constructing macro RNS.
[3.2.2] The phase P in the process in the proof of the above theorem 3.2.1 enable macros to depend only on their micros and the PRNS:es, but not on the rewrite objects which might contain large number or even unlimited number of places for redexis of rules in micros. Furthermore it is considerable that rules in can be spared to be constructed untill it is necessary in processes applying . It is also noticable that {tilde over (β)} k ′ and ã j ′ can be picked among letters or on the other hand e.g. {tilde over (β)}k′ can be chosen to be b k ′ and α j ′can be a n ′.
3.3. Parallel Process and the Closure of Abstract Languages
[0180] [3.3.1] Let be an arbitrary set and for each i,j ε let θ ij be the abstraction relation, and let {tilde over (θ)}=Π(θ ij : (i,j)ε for some ⊂ , thus {tilde over (θ)}-associated languages is called -abstract language
[3.3.2] Let be a set of RNS:es and TD over a We define a macro TD of in regard to denoted for which = ← ), where is a macro RNS for in regard to We say that is a micro TD of and denote it .
[3.3.3] Following “parallel”-theorem describes the invariability of the abstraction relation or the closures of abstract languages, and taking advantage of the equation of “altering macro RNS”-theorem it gives TD-solutions for any problem whose mother graph is an abstract sister to a graph which is the mother graph of a problem TD-solutions of which are known.
[3.3.4] “Parallel”-theorem 3.3.1. Let be a TD, θ the abstraction relation, a and b two nets, and two PRNS:es of c, a being a concept of c in and b a concept of c in . If aθb, then
1° a θ b , that is
θ is closed under transformator ( ), in other expression θ( ) ) ⊂ θ, and
2° a θ b , that is
θ is closed under transformator ), in other expression θ( ) ⊂ θ.
Proof. The claims of the theorem follow from “altering macro RNS”-theorem, because = , and rules of RNS:es in macro TD:es can be spared to be constructed untill it is necessary in processes applying micro RNS:es. □
We call and parallel with each other, and consequently on the other hand and are also parallel with each other. See FIG. 3 . 3 . 4 .
FIG. 3 . 3 . 4 describes the relation between parallel TD:es.
3.4. Abstract Algebras
[0181] [3.4.1] Lemma 3.4.1. All nets in any denumerable class of the abstraction relation have the shared substance (the center of that class).
Proof. Let θ be the abstraction relation and let H be a denumerable θ-class. Each substance and its concepts are in the same θ-class in according to corollary 3.1. Because H is an equivalence class being due to corollary 3.2, all substances in H are in θ-relation with each other. Repeating the reasoning above for substances of substances and presuming that H is denumerable we will finally obtain the claim of the lemma. □
See FIG. 3 . 4 . 1 for center c of a denumerable θ-class: a tree, where the node with no outputs is the center.
FIG. 3 . 4 . 1 is figuring the tree formation of a denumerable class of the abstraction relation.
[3.4.2] Lemma 3.4.2. Let θ be the abstraction relation restricted to the set of all distinct nets (thus we say θ is distinctive). Furthermore let not be a contents expanding TD, and let Q be a denumerable θ-class with c being its center. In addition we denote
=={ is a PRNS of c} ∪
Therefore
[0000]
Q =(c )θ.
Proof. Because θ is an equivalence relation and θ is distinctive, parallel theorem 3.3.1 yields Q ⊂ (c )θ. On the other hand, being due to our presumption for we obtain (c )θ ⊂ Q following from the construction for macros in the proof of the “altering macro RNS”-theorem and because is not increasing the number of partitions while applying it. □
[3.4.3] It is noticable that the restriction for θ in lemma 3.4.2 is merely of formal nature and contain any really restriction in practice, because each jungle is anytime possible to bound to a jungle of distinct nets by a suitable bijection.
[3.4.4] “Abstraction closure”-Theorem 3.4.1.
[0184] If there are in force following presumptions (i)-(iv):
(i) θ is the distinctive abstraction relation, (ii) A is the set of the denumerable θ-classes, (iii) is a TD, but not contents expanding and (iv) is as in lemma 3.4.2, and we denote ={ : c is the center of a θ-class},
[0189] then
[0000] A. pair (A, ) is an algebra.
[0190] If in addition to presumptions (i)-(iv) there is one more presumption (v):
={ cεM}, where M is the set of the centers of set H of denumerable θ-classes, then
B. pair ((M )θ, ) is an algebra (so called abstract algebra) with H as its generator set.
A-Proof. Lemma 3.4.2 yields claim A.
B-Proof. As a consequence of Parallel theorem 3.3.1 and lemma 3.4.2 any element in set is a center, whenever c is a center. □
[3.4.5] The above “abstraction closure”-theorem can be figured as follows: As far as contents in processes are not being expanded ( is not contents expanding), each abstraction (element in (M )θ) for the products (εM ) can be verified, if and only if we know each abstraction (element in H) for the elements (εM) to be processed.
§ 4. General Framework for Partition and Abstraction Relation
[0192] [4.1] Let φ be a relation in the set of the nets, and let be a TD. Let then a and be two nets in φ-relation with each other. In order to set up the general framework for partitions and the abstraction relation the first question is: what kind of TD is, if the products a and b are supposed to be in φ-relation with each other? See FIG. 4.1 .
FIG. 4.1 is clarifying the nature of the invariability of a relation in processing a pair of TD:es.
[4.2] The next step is to consider a relation between φ and apexes of the left sides of pairs in rules of RNS:es in We can imagine the case, where r is such an element in a rule of a RNS in that apex(left(r))∩enc(a)=Ø, but apex(left(r)) is not in any partition of net a. The more general case is described in the figure below, where there is more than one that kind of net a. See FIG. 4.2 , where {tilde over (r)} is the apex of r.
FIG. 4.2 is a complicated version of FIG. 4.1 with more than one element in the processed relation.
[4.3] We can imagine even more general case, where the relation θ to be studied, is defined in the set of the nets such that nets and are in θ-relation with each other, if there is such cover α for and such cover β for that θ consists of pairs where one part is in α and the other is in β, and these parts are in p-relation with each other. Those covers may consist of disjoined nets (thus θ is a ‘primitive’ ordinary relation and θ ⊂ φ) or intersected nets or they may form partitions, etc. See FIG. 4 . 3 . 1 , where A ⊂ α and B ⊂ β.
FIG. 4 . 3 . 1 describes a situation of FIG. 4.1 , where the relation is compiled by covers.
[0193] Notice that r→S may be deleting. However even in that case, if each net in cover α and on the other hand in cover β is unbroken, is changed by r→S only in those nets in α which intersect and apex(r), and the demand “ (r→S) and (p→Q) are in θ-relation with each other” are fulfilled, if A(r→S) and B(p→Q) are in θ-relation with each other.
[0194] The situation is more complicated, if in cover α and in cover β there are some broken nets, in which case nets totally isolated from redexes of r→S may be affected. See FIG. 4 . 3 . 2 of a cover of 3-successive net .
[0000] FIG. 4 . 3 . 2 is a figure of a 3-successive net and an effect of rewriting in totally isolated elements of a cover.
[0195] Notice that differing from the case in “altering macro RNS”-theorem p→Q is depending not only on θ and r→S, but also on the product (r→S) and not exclusively in the case ‘r→S is deleting’. However p depends only on relation φ and on the neighbouring nets of the redexes of r→S in cover α, if no pair in the rules of the RNS:es in is deleting. In general, if C is presenting the set of such nets in cover a which are affected by r→S, it must be that apex(p)εCθ, and Cθ(p→Q) is in θ-relation with C(r→S). That kind of large demands for p→Q when widening remembrance hunting in memories raises up the question about choosing the type of right covers and interacting RNS:es. That question is widely dealed with, and solved in the manner of the most general character in the next chapter.
§ 5. Controlling the Remembrance Hunting by Choosing Types of Interacting RNS:es
[0196] [5.1] In the following we are searching the solutions built by certain type of parts (elements in covers), this requirement is embedded in limit demands. The apexes of the left sides of the rules in RNS:es in known TD may not be elements in any partition of the mother graph of the problem studied, but merely in some more general cover of the mother graph fitting to limit demands. Thus we must study general covers (GCRNS:es) for mother graphs allowing the depth dimension (the overlapping of apexes in interacting rules are not necessarily enclosements in the rules), multiplication and new connections (between nodes; manoeuvre increasing ability), too. The relations between PRNS and GCRNS are especially in focus. We construct generalized macro/micro (GMA/GMI) TD for GCRNS. Abstraction relation θ is then defined as before except PRNS is replaced with different variations of GCRNS.
[5.1.1] For each relation λ we define relation RNS of λ, RNS(λ), such that
RNS(λ)={s→T:sεD(λ), T=sλ}.
[0198] Notice that in general there is in force equation [RNS(λ)] −1 =RNS(λ −1 ).
[0000] [5.1.2] Let s be a net. The relation ED of s, TD(s), is the TD over {RNS(λ): λ is a node in s}, such that the attaching mapping in the realization anchoring relation of the TD joins each node in s to the relation RNS of that particular node.
[5.1.3] is a cover RNS (CRNS) of net s, if it fulfils conditions (i)-(iv):
(i) is manoeuvre mightiness and arity mightiness saving,
(ii) there is such net s′ for which Se enc(s′) and
⊃ {L(s′)∩L(s′ )=└} (totally applicant ranked letters changing),
(iii) ∪(L(right((ω))) and set L(s) are distinct with each other, whenever ωε ,
(iv) {(left(ω),right( )): ωε } is an injection.
The set of all CRNS:es of net s is denoted CRNS(s). Observe that PRNS:es are examples of CRNS:es. We say that s is -cover result for S.
[5.1.4] It is useful to keep in mind that neglecting influence of limit demands, simultaneousness and finiteness, the generality order of the changing power of RNS:es (difference between left and right sides of rules) can be described as followes:
A. no difference (=totally restricted)
B. the mightiness of the positions of ranked letters
C. ranked letters
D. the mightiness of the arities
E. the mightiness of the positions of manoeuvre letters
F. manoeuvre letters.
[5.1.5] GPRNS is RNS which is defined as PRNS but the condition “manoeuvre mightiness saving” is replaced with demand “not manoeuvre deleting”, and GCRNS is RNS which is defined as CRNS with the above replacement.
CLAUSE 5.1. Let be a CRNS or even GCRNS of net a. If the right sides of the pairs in each rule of are distinct from each other (we say is distinct from right sides) (we reserve the symbols C d RNS and GC d RNS, respectively), then for each net a
a =a.
If is not distinct from right sides, then for each net a we have a ε a
Proof. (G)C d RNS is not manoeuvre deleting and is totally applicant ranked letters changing. □
Next we consentrate to make notions adequate for differences between PRNS and CRNS.
[5.2] “Characterization Clause”. Let a and b be two distinct nets. Then
|OS(a)|=|OS(b)| there is such CRNS that a =b
Proof. : CRNS is arity mightiness and manoeuvre mightiness saving, and therefore in the applicants of CRNS the mightiness of the set of the outside links of the redexes is not changing in derivations.
Proof. : Choose ={a→b}. □
The next characterization [5.3.0] says that the necessary and sufficient condition in order to be the result of a PRNS for a net is that there is a partition of the net and the unequivocal correlation between the elements of the partition and the letters of the result regarding the mightiness of the positions of the outside arities.
[5.3.0] “Characterization Clause”. Let a and b be nets. Then
(Π PεPar(a)) (∃ n ε{|OS(α,b)|: αεL°(b)}∪{|OS(t)|: tεP})
|⊚(p(P,t): |OS(t)|=n, tεP)|≠ ⊚(p(b,α):|OS(α,b)|=n, αεL°(b))|,
if and only if
a ≠b, whenever is a PRNS.
Proof. Each PRNS is manoeuvre mightiness and arity mightiness saving. □
Clearly CRNS is a genuine generalization of PRNS, and we can obtain even more restricting claim:
Clause 5.3.1
[0205] { is a nonconditional and not letter mightiness increasing CRNS} ⊃{ is a PRNS)}.
Proof. Clause 5.3.0 (see FIG. 5 . 3 . 1 ). □
FIG. 5 . 3 . 1 illustrates PRNS as a special case of more general cover RNS. In the figure b=a , where ={φ 1 ,φ 2 }.
Clauses 5.3.0 and 5.3.1 raise the questions:
1° Overall, for what kind of pair (a,b) we succeed in finding such GPRNS or GCRNS, that a =b? For PRNS and CRNS we already have characterization clauses 5.2. and 5.3.0.
2° For which net a and CRNS of a there is such PRNS of a that a =a ? A suitable PRNS-candidate is constructed in the following clause 5.3.1.1.
[5.3.1.1] Clause. 5.3.1.1. Let be a left-right distinct CRNS (that is: for each rules r of ω apex(left(r)) and apex(right(r)) are distinct from each other, whenever ωε ), and for each rεω and each ωε let
(∃ PεPar(left(r))) (∀n ε{|OS(α,right(r))|: α ε L(apex(right(r)))}∪{|OS(t)|: tεP}) |⊚(p(P,t): |OS(t)|=n, tεP)|=|∪(p(right(r),α): |OS(α,right(r))|=n, α ε L(apex(right(r)))|.
Hence there is such PRNS that = .
Proof. Being due to our presumptions for the rules of clause 5.3.0 yields that (∀rεω)(∀ωε )(∃ PRNS ) apex(right(r)) is -partition result for apex(left(r)). By choosing =U( :rεω,ωε ={ =∪( ̂: rεω,ωε ),{ :rεω,ωε }}) we'll get a desired PRNS, because is left-right distinct. □
[5.3.2] Notice that there is not always CRNS of net a, such that a =c(a) , whatever PRNS might be. E.g. c(a)εCov(a)\Par(a), hence |OS(c(a) )|≠|OS(a)|, whenever is PRNS. See characterization clause [5.2].
FIG. 5 . 3 . 2 is figuring differences between cover orders and partition RNS:es. In the figure c(a)={d,f}, ={α→γ, β→δ,d→e} and c(a) ⊃{e,g}.
Next in the following paragraphs we define cover reversely labelling RNS:es yielding the definition of generalized macros. Furthermore we prove “Altering Macro RNS”-theorem [3.2.1] to be generalized to deal also with wider interacting RNS-type, GC d RNS, and in order to extend problem solving to fit also to that interacting type, characterization of abstraction relation regarding the type is introduced.
[5.4.0] Let be a RNS of type T, Tε{C d RNS,GC d RNS}, and let r o →R be a pair in a rule of a RNS. We denote
a=∩(apex(t) ̂: apex(r o )εenc(apex(t) ̂), t is a net).
For r o let us define , a single partition relation (over ), such an injection in the set of the graphs that the sets of the apexes of the elements in its image sets are alphabets outside L(a) and any catenation of is itself, and the image of the relation RNS of is manoeuvre mightiness and arity mightiness saving.
[0209] For each ωε we define such set P ω (r o ,f ωr o , {f r o r : rεω}) of rules that
[0000] {left( r ): r εφ r , φ r ε P ω (r o , f ωr o {f r o r : rεω})}={left(p){ν→f ωr o (ν):apex(ν)εPI(N), N ⊂ apex(left(p)) ({apex(right(s)):sεω}∪{apex)r o ){), ν matches left(p){:pεω}, and for each r (= r (r)) in each φ r (being an image set for r) εP ω (r o , , {f r o r : rεω}) right( r )=left( r ){ν→f r o r (ν):apex(ν)ε{apex( (μ)): μ is a graph}∪(apex(left( r ))={apex (μ)):μis a graph{), ν matches left( r )}, where for each r εω, f r o r , a generalized partition relation (over ), is such an injection in the set of the graphs that the sets of the apexes of the elements in its image sets are the same alphabets as is the matter concerning , and any catenation of f r o r is f r o r itself, and the image of the relation RNS of f r o r is of the same type as and furthermore for (each rεω) φ r ={ r : left( r )ε{left(r){ν→ (ν):apex(ν)εPI(N), N ⊂ apex(left(r)) ({apex(right(s)): sεω}∪{apex(r o )}), ν matches left(r)}, and for each r in each φ r ε (r o , r o ,{f r o r : rεω}) e→right(r) is manoeuvre mightiness and arity mightiness saving, whenever e∈right( r (r)). Let Q be such that R→Q is of the same type as We denote
=U(P a (r o , , {f r 0 r : r∈ω}):ω∈ (r←φ r :r∈ω, ω∈ )).
Let p=r o ̂. We define a cover reversely labeling RNS
ZRNS( ,r o )={μ→ν: μ matches right(p), apex(μ)=apex(right(p)) apex(left(q)),
ν matches right( s ), apex(ν)=apex(right( s )) apex(left(t)), p, q ε ω, S , t ,ε φ r , φ r εP ω (r p , , {f r o r : rεω{),ωε .}.
Now we say that ZRNS( ,r o )̂(p→Q) is a GMA of r o →R in regard to and , denoted GMA(r o →R, ). If we want to emphasize the importance of generalized partition relations, notation GMA(r o →R, ) is used, where =( ,{f r o r : rεω,ωε }). We say that
{GMA(r, ): rεφ, φε (r←GMA(r, f left(r)ω ) :rεφ, φε )}
is a generalized macro RNS of in regard to and (={ f left(r) : rεφ, φε }; we reserve the notation for that purpose), denoted GMA ( ) or If we do not want to specify partition relations we simply denote . In this connection we want to make noticeable that if would be allowed to be manoeuvre deleting, there does not always exist GMA for a given rule.
[5.4.1] Let be a set of RNS:es and a TD over and let be a GC d RNS, whenever We define a generalized macro TD of in regard to ( ,f)( ) (={( ): }), GMA( ( ,f)( )), denoted also , such that
= : is a GC d RNS, ):
denoted , if it is not wanted to specify partition relations. We say that is a generalized micro TD of , and denote it . Furthermore for each TD we denote
(T)={ : is of type T} and −(T)={ : is a type of T},
whenever Tε{PRNS, GPRNS, C d RNS, GC d RNS}. Notice that because GC d RNS:es are genuine generalizations of GPRNS:es we have equations
[0000] (GPRNS)⊂ (GC d RNS) and (GPRNS) ⊂ (GC d RNS).
[0000] [5.4.1.1] Clearly we can generalize theorem 3.2.1 as follows:
Theorem 5.4.0. Theorem 3.2.1(RNS←TD,PRNS←GPRNS).
[0218] [5.4.2] Theorem 5.4.1. For each C d RNS and on the other hand GC d RNS, and each RNS there is GMA( ), and such PRNS and GPRNS respectively, , that
( )̂=
Proof. Let r o ←R be in a rule of , and let net a be as in definition [5.4.0]. Because the image set of the relation RNS of each single partition relation is manoeuvre mightiness and arity mightiness saving, then RNS for which
=∪(F ω (r o , r o {f r o r : rεω}): ωε (r→φ r : rεω,ωε U)),
where for each ωε , F ω (r o , , {f r o r : rεω}) is the set of rules ν→ (ν), ν→f r o r (ν) defined as in the definition of r , is a GPRNS of net al. Because is distinct from right sides and not manoeuvre deleting, so regardless of which type of interacting RNS in our theorem is chosen we obtain
a ̂=a ̂=a ZRNS( ,r o )̂,
and the claim of our theorem follows from theorem 5.4.0. See FIG. 5 . 4 . 2 . □
FIG. 5 . 4 . 2 In the figure we have =(α→α′)(β→β′)(γ→γ′)(δ→δ′), cεa ̂, c 1 ̂εCov(a), areas in c having a dot are ranked letters (e.g. |{ {tilde over (α)} ′,σ):σεL°( {tilde over (α)} ′)}|=8), and symbolies the apex of whenever is a net. In the picture the apexes of the left and the right sides of p 2 , p 3 and p 4 , respectively, are supposed to be one upon another, the right sides uppermost.
ZRNS( ,r o )̂(p→Q) is a GMA of r o →R. Furthermore we have
ZRNS( ,r o )̂ ⊃ r 1 r 2 r 3 r 4 , where
apex(left(r 1 ))={tilde over (δ)}′, apex(right(r 1 ))= {tilde over (δ)} ′; apex(left(r 2 ))={tilde over (γ)}′ {tilde over (δ)}′, apex(right(r 2 ))= {tilde over (γ)} ′ {tilde over (δ)} , apex(left(r 3 ))={tilde over (β)}′ ({tilde over (γ)}β{tilde over (δ)}), apex(right(r 3 ))= {tilde over (β)} ′ ( {tilde over (γ)} β {tilde over (δ)} );
apex(left(r 4 ))={tilde over (α)}′ ({tilde over (β)}∪{tilde over (γ)}∪{tilde over (δ)}), apex(right(r 4 ))= {tilde over (α)} ′ ( {tilde over (β)} ∪ {tilde over (γ)} ∪ {tilde over (δ)} ).
̂p 1 p 2 p 3 p 4 , where apexes of left and right sides in p 2 , p 3 and p 4 are shaded, and all letters in the right sides of p 1 ,p 2 ,p 3 and p 4 are denoted with dots.
apex(left(p 1 ))={tilde over (α)}, apex(right(p 1 ))= {tilde over (α)} ′; apex(left(p 2 ))= {tilde over (β)} , apex(right(p 2 ))= {tilde over (β)} ′;
apex(left(p 3 ))= {tilde over (γ)} , apex(right(p 3 ))= {tilde over (γ)} ′; apex(left(p 4 ))= {tilde over (δ)} , apex(right(p 4 ))= {tilde over (δ)} ′.
As each Cartesian power of each net is a net, theorem 5.4.1 yields the following theorem:
Theorem 5.4.2. For each GC d RNS and each TD over set of RNS:es, there is , and such GPRNS that
̂( )̂= .
[5.5.0] Fig. of Memory Hunting illustrates iterative process of probing known transducers in memory by cover rewriting systems in order to transform them by cover reversely labelling RNS:es. In the figure a, b, c, b 1 , c 1 , b 2 , c 2 and b 3 are nets.
[5.5.1] Fig. of Process Summarization (Automated Problem Solving System) RPG describes the relations between known TD:es and TD:es (b, ) solving given problem (b, ) belonging to language recognized by .
[0223] The mother graph b of given problem (b, ) is first transformed by right sides distinct cover renetting to net β for which we construct an abstract sister, here α, one of the substances of which has a partition being in bijection with a partition of one of the substances of β. From known transducer ( ), enabling to construct interacting (G)PRNS:es between g and α° and on the other hand between g and β°, we then construct (parallel ( ) , and by iteration we reach for our original problem (b, ) a presolution (b, ), which finally is a desired solution, if first of all accepts the product that is product (b, ) (b, ) ε and moreover the product fulfills limit demands .
[0224] Being due to corollary 3.2 we may direct consider result (b, ) macro(micro( )) via some substance f for mother graphs a and b (substances for abstract sisters α and β), but in the case the interacting RNS:es and would be very difficult or even impossible to acquire, if a or b is undenumerable (and actually even if the mightiness of one of them is considerable although denumerable).
[0225] Symbol θ stands for a generalized abstraction relation, and are interacting RNS:es, and furthermore TD:es and parallel ( ) are parallel with each other, a being macro of and (parallel( )) being micro of parallel .
[0226] The dots in nets a° and β° in the figure represent letters (as results of GPRNS:es) and the small squares in nets a, b, a° and β° stand for matching areas (the sets of redexes) of rules in RNS:es of transducers. Symbols η, κ, λ and λ are enclosements.
[0000] [5.6.1] The generalized abstraction relation in regard to type T of interacting RNS, GAR(T), (e.g. Tε{PRNS,GPRNS,C d RNS,CRNS,GC d RNS,GCRNS}), (in short abstraction relation of toe T) is such a binary relation of the pairs of nets, where for each pair (here (s,t)) there is such net c and interacting RNS:es and of type T, that
c ̂=s and c ̂=t.
Nets s and t are said to be abstract sisters of type T with each other, c being a substance of s and t. Notice that GAR is a genuine generalization for abstraction relation AR, and that AR=GAR(PRNS).
[5.6.2] Clause. “A characterization of generalized abstraction relation GAR(CRNS)”. Let a and b be two nets and let θ be GAR(CRNS). Then
a θb |OS(a)|=|OS(b)|.
Proof. Theorem 3.1 and clause 5.2. □
[5.6.2.1] We can straightforwardly widen the definition for “parallel” to deal with interacting RNS:es of type GPRNS, C d RNS and GC d RNS instead of solely dealing with type PRNS. Therefore we clearly have the results for GAR(C d RNS) as is obtained for AR: corollaries 3.1 and 3.2, and result [3.1.9], parallel-theorem, lemmas [3.4.1] and [3.4.2], theorem [3.4.1], and result [3.4.5].
[5.6.3] Clause. “Characterization of GAR”. Let Tε{GC d RNS,GCRNS} and let s and t be nets. Then s and t are abstract sisters of type T, if and only if there exist such interacting RNS:es and of type T that
(∃A s , εPar(s )̂) and (∃A t εPar(t )̂) there is a bijection between A s and A t .
Proof. FIG. 5 . 6 . 3 describes a typical phase in iteration of the general case for interacting RNS of type GCRNS. □
In FIG. 5 . 6 . 3 a, b, α, β and γ are nets and x, y and z are frontier letters, z is chosen to be connected to the same net as x, o characterizes occupied and α stands for unoccupied.
[5.7.1] Let θ be a relation in the set of the nets. We say that θ is a generalized congruent relation of type T (e.g. Tε{PRNS,GPRNS,C d RNS,CRNS,GC d RNS,GCRNS}), if there is in force:
a θ b aφ a θb b whenever φ a and φ b are renetting rules in RNS:es of type T.
Each generalized congruent relation of type T, which is an equivalence relation, is entitled generalized congruence relation of type T. The set of all generalized congruence relations of type T is denoted GCg(T).
[5.7.2] Theorem. GAR(T)εGCg(T), whenever Tε{PRNS,CRNS}.
Proof. Clause [5.6.2].□
[5.7.3] Theorem. GAR(T) E GCg(T), whenever Tε{GPRNS,GCRNS}.
Proof. Because there is only one rule to reverse, it is not required demand “distinct from right sides” and therefore clause 5.1 yields that GAR(GCRNS) is congruent. Equivalence followes from characterization clause 5.6.3. □
[5.7.4] CONCLUSION. Hence there is in force the same generalization of results of AR for GAR(GC d RNS) as we introduced for GAR(C d RNS) in [5.6.2.1].
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The invention gives desired algorithmic solutions, even impossible to derive denumerably from preceding ones, as transducers for any kind of problem, e.g. groups of equations or construction puzzles with variables unlimited even by type. The invention treats problems as triples of a mother graph as the subject of the problem, a solving determining recognizer and limit demands for proper solution types. The invention disperses the mother graphs into abstract partial problems regarding chosen interacting rewriting types with mutual relations controlling profoundness in memory hunting, and by bijective partitions creates abstract sisters for those conceptual graphs. As solutions for the examined problems are micros for the parallel transducers of macros of known solving transducers having common parts with substances of those macros and being not necessarily limited to reducing ones. All conceivable solutions are obtained interacting rewrite type being right sides distinct generalized cover renetting, if the mother graph is denumerable and contents in iteration are not expanded. As an exact universal mathematical structure of controlling inventiveness the invention can be considered as the prime algorithm of independently programs inventing machines for problem solving.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2012-0039129, filed on Apr. 16, 2012, the entirety of which is incorporated by reference herein.
BACKGROUND
The inventive concept relates to methods of manufacturing a fiber and, more particularly, to methods of manufacturing a graphene fiber.
Fibers have been increasingly demanded with an increase of population and development of an industry. New fibers having more excellent function than a natural fiber have been increasingly demanded. Dupont Co. (U.S.A) announced a new synthetic fiber so-called ‘Nylon’ in 1938. Thereafter, a polyester fiber, an acrylic fiber, and a polyurethane fiber have been developed. Recently, various researches have been conducted for high performance and high functional fibers and nano fibers using new materials overcoming performance limitation of existing materials.
Graphene includes carbon atoms constituting hexagonal shapes. Each of hexagonal shapes may consist of six carbon atoms. The graphene has a single-layered structure where the hexagonal shapes are two-dimensionally arranged. The structure of the graphene may be similar to that of graphite consisting of plates three-dimensionally stacked. The plates of the graphite may be divided to form the graphene. For example, the plates of the graphite may be divided using a scotch tape. The graphene may have excellent properties such as a surface area (e.g., about 2650 m 2 /g) two times or more than active carbon, a high elasticity force (e.g., about 1 TPa), and chemical stability as well as electric properties such as high conductivity (e.g., 1×10 −6 Ωcm) and high electron mobility. Recently, it has been announced that the graphene also has antibiosis removing bacteria. Thus, the graphene have been developed in various fields such as a display, a cathode material of a lithium-ion battery, an electrode material of an electric double-layered capacitor, environmental filters, and biomaterials.
SUMMARY
Embodiments of the inventive concept may provide methods of easily manufacturing a graphene fiber having a large area.
According to embodiments of the inventive concept, a method of manufacturing a graphene fiber includes: forming a supporting fiber; forming a graphene oxide-containing solution; coating the supporting fiber with the graphene oxide-containing solution to form a graphene oxide composite fiber; and separating the supporting fiber from the graphene oxide composite fiber.
In some embodiments, the supporting fiber may be a polymer fiber. A polymer solution may be electro-spun on a collector to form the polymer fiber. The polymer solution may be formed by dissolving a polymer material in a solvent. The polymer fiber may have insolubility to by using an ammonia solution or a sodium hydroxide solution. The polymer fiber may be coated with an amine group-containing solution so that the polymer fiber may have a high reactivity with respect to graphene oxide. The amine group-containing solution may include at least one of bovine serum albumin (BSA), amyloid beta, poly-D-lysine, poly-L-lysine, and chitosan.
In other embodiments, forming the graphene oxide composite fiber may include: self-assembling graphene oxide of the graphene oxide-containing solution and the supporting fiber.
In still other embodiments, separating the supporting fiber from the graphene oxide composite fiber may include: thermally treating or chemically melting the graphene oxide composite fiber. The thermal treating may be performed at a temperature within a range of about 25 degrees Celsius to about 3000 degrees Celsius (particularly, a range of about 100 degrees Celsius to about 3000 degrees Celsius) for a thermal treating time within a range of about 1 minute to about 24 hours. The chemical melting may be performed using an acid-based solvent. The acid-based solvent may include at least one of acetic acid (C 2 H 4 O 2 ), formic acid (HCOOH), citric acid (C 6 H 8 O 7 ), hydrochloric acid (HCl), sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), perchloric acid (HClO 4 ), fluoric acid (HF), phosphoric acid (H 3 PO 4 ), chromic acid (HCrO 4 ), CH 3 CH 2 COOH, oxalic acid, glycol acid, tartaric acid (C 4 H 5 O 6 ), acetone, and toluene.
In even other embodiments, the method may further include: reducing the graphene oxide composite fiber to a graphene composite fiber. The graphene composite fiber may be reduced from the graphene oxide composite fiber by a thermal reduction method, an optical reduction method, or a chemical reduction method. The thermal reduction method may be performed at a temperature within a range of about 40 degrees Celsius to about 3000 degrees Celsius. The optical reduction method may use light of a wavelength within a range of about 200 nm to about 1500 nm. The chemical reduction method may use a chemical reagent including at least one of hydriodic acid with acetic acid (HI—AcOH), hydrazine (N 2 H 4 ), dimethyl hydrazine (C 2 H 8 N 2 ), sodium borohydride (NaBH 4 ), sodium hydroxide (NaOH), ascorbic acid, glucose, hydrogen sulfide (H 2 S), hydroquinone (C 6 H 4 (OH) 2 ), and sulfuric acid (H 2 SO 4 ).
BRIEF DESCRIPTION OF THE DRAWINGS
The inventive concept will become more apparent in view of the attached drawings and accompanying detailed description.
FIG. 1 is a flow chart illustrating a method of manufacturing a graphene fiber according to some embodiments of the inventive concept;
FIG. 2 is a flow chart illustrating a method of manufacturing a graphene fiber according to other embodiments of the inventive concept;
FIG. 3 is a schematic diagram illustrating an electro spinning apparatus according to embodiments of the inventive concept;
FIG. 4 , a schematic diagram illustrating a process of a method of manufacturing a graphene fiber according to embodiments of the inventive concept;
FIG. 5 is an enlarged view of a portion ‘A’ of FIG. 4 ;
FIG. 6 is a schematic diagram illustrating a graphene oxide composite fiber according to embodiments of the inventive concept;
FIG. 7 is an enlarged view of a cross section taken along a long axis of a portion “B” of FIG. 6 ;
FIG. 8 is a scanning electron microscope (SEM) photograph of a chitosan fiber formed by a first experimental example; and
FIG. 9 is a SEM photograph of a graphene oxide composite fiber formed by a first experimental example.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the inventive concept are shown. The advantages and features of the inventive concept and methods of achieving them will be apparent from the following exemplary embodiments that will be described in more detail with reference to the accompanying drawings. It should be noted, however, that the inventive concept is not limited to the following exemplary embodiments, and may be implemented in various forms. Accordingly, the exemplary embodiments are provided only to disclose the inventive concept and let those skilled in the art know the category of the inventive concept. In the drawings, embodiments of the inventive concept are not limited to the specific examples provided herein and are exaggerated for clarity.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular terms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it may be directly connected or coupled to the other element or intervening elements may be present.
Similarly, it will be understood that when an element such as a layer, region or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present. In contrast, the term “directly” means that there are no intervening elements. It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Additionally, the embodiment in the detailed description will be described with sectional views as ideal exemplary views of the inventive concept. Accordingly, shapes of the exemplary views may be modified according to manufacturing techniques and/or allowable errors. Therefore, the embodiments of the inventive concept are not limited to the specific shape illustrated in the exemplary views, but may include other shapes that may be created according to manufacturing processes. Areas exemplified in the drawings have general properties, and are used to illustrate specific shapes of elements. Thus, this should not be construed as limited to the scope of the inventive concept.
It will be also understood that although the terms first, second, third etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element in some embodiments could be termed a second element in other embodiments without departing from the teachings of the present invention. Exemplary embodiments of aspects of the present inventive concept explained and illustrated herein include their complementary counterparts. The same reference numerals or the same reference designators denote the same elements throughout the specification.
FIG. 1 is a flow chart illustrating a method of manufacturing a graphene fiber according to some embodiments of the inventive concept.
Referring to FIG. 1 , first, a supporting fiber may be formed (S 10 ). The supporting fiber may be a polymer fiber. A polymer solution may be electro-spun on a collector to form the polymer fiber. The polymer solution may be formed by dissolving a polymer material in a solvent.
The polymer material may include at least one of polyamide-6, polyamide-6,6, polyurehthanes, polybenzimidazole, polyacrylonitrile, polyaniline (PANI), polyvinylcarbazole, polyacrylamide (PAAm), polyimide, poly-metaphenylene isophtalamides, polylactic-co-glycolic acid, poly caprolactone, polyglycolide, poly lactic acid, poly-3-hydroxylbutyrate, betaamyloid, collagen, fibrin, chitosan, and gelatin.
The solvent may include at least one of water, ethanol, methanol, acetone, phosphate buffered saline (PBS) buffer, acetic acid (C 2 H 4 O 2 ), formic acid (CH 2 O 2 ), hexafluoro-2-propanol ((CF 3 ) 2 CHOH), trifluoroaceticacid (C 2 HF 3 O 2 ), dichloromethane (CH 2 Cl 2 ), acetonitrile (C 2 H 3 N), benzene (C 6 H 6 ), 1-butanol (C 4 H 10 O), 2-butanol (C 4 H 10 O), 2-butanone (C 4 H 8 O), t-butyl alcohol (C 4 H 10 O), carbon tetrachloride (CCl 4 ), chlorobenzene (C 6 H 5 Cl), chloroform (CHCl 3 ), cyclohexane (C 6 H 12 ), 1,2-dichloroethane (C 2 H 4 Cl 2 ), dichlorobenzene, diethyl ether (C 4 H 10 O), diethylene glycol (C 4 H 10 O 3 ), diglyme (diethylene glycol, dimethyl ether) (C 6 H 14 O 3 ), 1,2-dimethoxy-ethane (glyme, DME, C 4 H 10 O 2 ), dimethylether (C 2 H 6 O), dimethyl-formamide (DMF, C 3 H 7 NO), dimethyl sulfoxide (DMSO, C 2 H 6 OS), dioxane (C 4 H 8 O 2 ), ethyl acetate (C 4 H 8 O 2 ), ethylene glycol (C 2 H 6 O 2 ), glycerin (C 3 H 8 O 3 ), heptanes (C 7 H 16 ), hexamethylphosphoramide (HMPA, C 6 H 18 N 3 OP), hexamethylphosphoroustriamide (HMPT, C 6 H 18 N 3 P), hexane (C 6 H 14 ), methyl t-butyl ether (MTBE, C 5 H 12 O), methylene chloride (CH 2 Cl 2 ), N-methyl-2-pyrrolidinone (NMP, CH 5 H 9 NO), nitromethane (CH 3 NO 2 ), pentane (C 5 H 12 ), petroleum ether (ligroine), 1-propanol (C 3 H 8 O), 2-propanol (C 3 H 8 O), pyridine (C 5 H 5 N), tetrahydrofuran (THF, C 4 H 8 O), toluene (C 7 H 8 ), triethyl amine (C 6 H 15 N), o-xylene (C 8 H 10 ), m-xylene (C 8 H 10 ), and p-xylene (C 8 H 10 ).
A concentration of the polymer material in the polymer solution may have a range of about 0.1 wt % (weight percent) to about 50 wt %.
FIG. 3 schematically illustrates an electro spinning apparatus used for forming the supporting fiber in the step S 10 of FIG. 1 .
Referring to FIG. 3 , a collector 25 may include a support part 24 and a form part 23 . The form part 23 may have a plate-shape or a circular shape. The collector 25 may include a conductive material or a non-conductive material. The conductive material may include at least one of gold, silver, aluminum, copper, stainless, palladium, platinum, silicon, poly-silicon, a conductive polymer, carbon nanotube, graphene, and indium tin oxide (ITO). The non-conductive material may include at least one of glass, quartz, acryl, a OHP film, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), PES, PEEK, polyimide (PI), polynorbonene, polyarylate, polycarbonate (PC), PAR, PDMS, and non-woven fabric.
The method of forming the polymer fiber (i.e., the supporting fiber) will be described with reference to FIG. 3 . The polymer solution may be provided into a cylinder 21 and then the polymer solution may be electro-spun on a surface of the form part 23 of the collector 25 through a nozzle 22 of the cylinder 21 . At this time, a specific voltage may be applied between the cylinder 21 and the collector 25 . Thus, the polymer fiber 26 may be formed on the surface of the form part 23 of the collector 25 . The polymer fiber 26 may have a diameter within a range of about 1 nm to about 100 μm. The nozzle 22 may be single-mode. If the nozzle 22 is the single mode, the nozzle 22 may have one hole. Alternatively, the nozzle 22 may be multi-mode. If the nozzle 22 is the multi-mode, the nozzle 22 may have two or more holes. For example, if the nozzle 22 is dual-mode, the nozzle 22 may have two holes having a first hole and a second hole surrounding the first hole.
The polymer fiber may have insolubility by using an ammonia solution or a sodium hydroxide (NaOH) solution. The polymer fiber may be coated with an amine group-containing solution, so that the polymer fiber may have a high reactivity with respect to a graphene oxide. The amine group-containing solution may include at least one of bovine serum albumin (BSA), amyloid beta, poly-D-lysine, poly-L-lysine, and chitosan. The polymer fiber may be separated from the collector 25 by a vacuum dry process.
Referring to FIG. 1 again, a graphene oxide-containing solution may be formed (S 20 ). Graphene oxide particles may be dispersed in a solvent, thereby forming the graphene oxide-containing solution.
The solvent of the graphene oxide-containing solution may include at least one of water, acetic acid (C 2 H 4 O 2 ), acetone (C 3 H 6 O), acetonitrile (C 2 H 3 N), benzene (C 6 H 6 ), 1-butanol (C 4 H 10 O), 2-butanol (C 4 H 10 O), 2-butanone (C 4 H 8 O), t-butyl alcohol (C 4 H 10 O), carbon tetrachloride (CCl 4 ), chlorobenzene (C 6 H 5 Cl), chloroform (CHCl 3 ), cyclohexane (C 6 H 12 ), 1,2-dichloroethane (C 2 H 4 Cl 2 ), dichlorobenzene, dichloromethane (CH 2 Cl 2 ), diethyl ether (C 4 H 10 O), diethylene glycol (C 4 H 10 O 3 ), diglyme (diethylene glycol, dimethyl ether) (C 6 H 14 O 3 ), 1,2-dimethoxy-ethane (glyme, DME, C 4 H 10 O 2 ), dimethylether (C 2 H 6 O), dimethyl-formamide (DMF, C 3 H 7 NO), dimethyl sulfoxide (DMSO, C 2 H 6 OS), dioxane (C 4 H 8 O2), ethanol (C 2 H 6 O), ethyl acetate (C 4 H 8 O 2 ), ethylene glycol (C 2 H 6 O 2 ), glycerin (C 3 H 8 O 3 ), heptanes (C 7 H 16 ), hexamethylphosphoramide (HMPA, C 6 H 18 N 3 OP), hexamethylphosphoroustriamide (HMPT, C 6 H 18 N 3 P), hexane (C 6 H 14 ), methanol (CH 4 O), methyl t-butyl ether (MTBE, C 5 H 12 O), methylene chloride (CH 2 Cl 2 ), N-methyl-2-pyrrolidinone (NMP, CH 5 H 9 NO), nitromethane (CH 3 NO 2 ), pentane (C 5 H 12 ), petroleum ether (ligroine), 1-propanol (C 3 H 8 O), 2-propanol (C 3 H 8 O), pyridine (C 5 H 5 N), tetrahydrofuran (THF, C 4 H 8 O), toluene (C 7 H 8 ), triethyl amine (C 6 H 15 N), o-xylene (C 8 H 10 ), m-xylene (C 8 H 10 ), and p-xylene (C 8 H 10 ).
Referring to FIG. 1 , a graphene oxide composite fiber may be formed (S 30 ). The graphene oxide composite fiber may be formed using the supporting fiber formed in the step S 10 and the graphene oxide-containing solution formed in the step S 20 .
FIG. 4 is a schematic diagram illustrating a process of a method of manufacturing a graphene fiber according to embodiments of the inventive concept, and FIG. 5 is an enlarged view of a portion ‘A’ of FIG. 4 . FIG. 6 is a schematic diagram illustrating a graphene oxide composite fiber according to embodiments of the inventive concept, and FIG. 7 is an enlarged view of a cross section taken along a long axis of a portion ‘B’ of FIG. 6 .
The method of forming the graphene oxide composite fiber will be described in detail with reference to FIGS. 4 to 7 . The supporting fiber 32 formed in the step S 10 may be provided into the graphene oxide-containing solution 31 formed in the step S 20 . As described above, the supporting fiber 32 may be the polymer fiber. And then a hydrogen chloride solution may be added to the graphene oxide-containing solution 31 to control a hydrogen ion concentration (pH) of the graphene oxide-containing solution 31 at or below about 5. Thus, the supporting fiber 32 having positive charges on a surface thereof and a graphene oxide 33 having negative charges may be self-assembled to form the graphene oxide composite fiber 34 of FIGS. 5 and 6 . In a cross section of the graphene oxide composite fiber 34 as illustrated in FIG. 7 , the graphene oxide composite fiber 34 may include the supporting fiber 32 and the graphene oxide 33 surrounding the supporting fiber 32 .
Referring to FIG. 1 , the supporting fiber 32 may be separated from the graphene oxide composite fiber 34 formed in the step S 30 (S 40 ). As described above, the supporting fiber 32 may be the polymer fiber. The graphene oxide composite fiber 34 may be thermally treated or chemically melted so that the supporting fiber 32 may be separated from the graphene oxide composite fiber 34 . For example, the graphene oxide composite fiber 34 may be thermally treated at a temperature within a range of about 25 degrees Celsius to about 3000 degrees Celsius (particularly, a range of about 100 degrees Celsius to about 3000 degrees Celsius) for a thermal treating time within a range of about 1 minute to about 24 hours. The chemical melting of the supporting fiber 32 in the graphene oxide composite fiber 34 may be performed using an acid-based solvent. The acid-based solvent may include at least one of acetic acid (C 2 H 4 O 2 ), formic acid (HCOOH), citric acid (C 6 H 8 O 7 ), hydrochloric acid (HCl), sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), perchloric acid (HClO 4 ), fluoric acid (HF), phosphoric acid (H 3 PO 4 ), chromic acid (HCrO 4 ), CH 3 CH 2 COOH, oxalic acid, glycol acid, tartaric acid (C 4 H 5 O 6 ), acetone, and toluene.
The graphene fiber may be manufactured by the method described above. The graphene fiber may have a structure including an outer surface and an inner surface surrounded by the outer surface. And the graphene fiber may include graphene oxide particles between the outer surface and the inner surface. An inner diameter of the graphene fiber may have a range of about 1 nm to 100 μm. A length of the graphene fiber may be several nanometers or more.
FIG. 2 is a flow chart illustrating a method of manufacturing a graphene fiber according to other embodiments of the inventive concept.
Referring to FIG. 2 , a supporting fiber may be formed (S 10 ) and then a graphene oxide-containing solution may be formed (S 20 ). Subsequently, a graphene oxide composite fiber may be formed using the supporting fiber and the graphene oxide-containing solution (S 30 ). The method of forming the supporting fiber, the graphene oxide-containing solution and the graphene oxide composite fiber may be substantially the same as the method described with reference to FIG. 1 .
Thereafter, the graphene oxide composite fiber formed in the step S 30 may be reduced to form a graphene composite fiber (S 50 ). The reduction method may include at least one of a thermal reduction method, an optical reduction method, and a chemical reduction method. The thermal reduction method may be performed at a temperature within a range of about 40 degrees Celsius to about 3000 degrees Celsius. The optical reduction method may be performed using light having a wavelength within a range of about 200 nm to about 1500 nm. The chemical reduction method may be performed using a chemical reagent including at least one of hydriodic acid with acetic acid (HI—AcOH), hydrazine (N 2 H 4 ), dimethyl hydrazine (C 2 H 8 N 2 ), sodium borohydride (NaBH 4 ), sodium hydroxide (NaOH), ascorbic acid, glucose, hydrogen sulfide (H 2 S), hydroquinone (C 6 H 4 (OH) 2 ), and sulfuric acid (H 2 SO 4 ).
The supporting fiber may be separated from the graphene composite fiber formed in the step S 50 (S 60 ). The supporting fiber may be the polymer fiber. The graphene composite fiber may be thermally treated or chemically melted so that the supporting fiber may be separated from the graphene composite fiber. The thermal treating and the chemical melting of the graphene composite fiber may be performed by the same method as described in the step S 40 of FIG. 1 .
The graphene fiber may be manufactured by the method described above. The graphene fiber may include an outer surface, an inner surface surrounded by the outer surface, and graphene particles between the outer surface and the inner surface. An inner diameter of the graphene fiber may have a range of about 1 nm to 100 μm. A length of the graphene fiber may be several nanometers or more.
EXPERIMENTAL EXAMPLE 1
A chitosan fiber was formed by the step S 10 . A chitosan powder (Sigma Aldrich Co. LLC.) was supplied into a trifluoroacetic acid solution and then the trifluoroacetic acid solution including the chitosan powder was mixed by a stirrer at 50 degrees Celsius for 6 hours, thereby forming a chitosan solution.
After the formed chitosan solution was supplied into the cylinder 21 of FIG. 3 , the chitosan solution was electro-spun to the collector 25 under the condition that the applied voltage was 15 kV, a distance between the cylinder 21 and the collector 25 was 10 cm, and a solution injection speed was within a range of about 1 ml/h to about 5 ml/h. A chitosan fiber having a diameter within a range of several nanometers to several micrometers may be formed according to a spinning condition of a concentration of the chitosan solution and the applied voltage. The chitosan fiber was neutralized in an ammonia solution for about 4 hours and then was cleaned three times by distilled water so that the chitosan fiber had insolubility. After the chitosan fiber was dried in a vacuum oven for about 24 hours, the chitosan fiber was separated from the collector 25 . A scanning electron microscope (SEM) photograph of the chitosan fiber formed at this time is illustrated in FIG. 8 . Referring to FIG. 8 , a diameter of the chitosan fiber was within a range of about 251 nm to about 331 nm.
The graphene oxide-containing solution was formed by the step S 20 . Modified Hummers and offenmans methods were performed on SP-1 graphite powder (Bay carbon Co.) so that graphene oxide powder was formed. After the graphene oxide powder was added to distilled water in a weight ratio of about 0.05 wt % to about 0.5 wt %, the graphene oxide powder was dispersed in the distilled water by an ultrasonic method for about 4 hours. Thus, a graphene oxide-containing solution was formed. Sizes of particles of the graphene oxide were within a range of about 0.5 nm to about 2.9 nm.
The graphene oxide composite fiber was formed according to the step S 30 . After the hydrogen ion concentration (pH) of the formed graphene oxide solution was adjusted at about 4.3, the formed chitosan fiber was soaked in the graphene oxide solution having the hydrogen ion concentration (pH) of about 4.3 for about 5 hours. Amide groups formed on the surface of the chitosan fiber and hydroxyl groups and carboxyl groups of the graphene oxide were self-assembled to form the composite fiber of a graphene oxide chitosan coaxial type. After the formed graphene oxide composite fiber was taken out, the graphene oxide composite fiber was cleaned three times by distilled water and then was dried in a vacuum oven for about 24 hours. A SEM photograph of the graphene oxide composite fiber formed at this time is illustrated in FIG. 9 . Referring to FIG. 9 , a diameter of the graphene oxide composite fiber was a range of about 500 nm to about 800 nm.
The graphene oxide composite fiber was reduced to form the graphene composite fiber according to the step S 50 . The graphene oxide composite fiber was reduced to the graphene composite fiber by a room temperature vapor method using a hydriodic acid with acetic acid (HI—AcOH) solution. In more detail, the graphene oxide composite fiber was supplied into an airtight glass container in which a mixture solution of hydriodic acid of about 2 ml and acetic acid of 5 ml was supplied. And then the graphene oxide composite fiber and the mixture solution were reacted with each other at about 40 degrees Celsius for about 24 hours. Thus, the reduced graphene composite fiber was formed.
The chitosan fiber being the supporting fiber was separated from the reduced graphene fiber according to the step S 60 . In more detail, the graphene composite fiber may be thermally treated at a temperature within a range of about 100 degrees Celsius to about 200 degrees Celsius for about 24 hours or be soaked in the acid-based solvent for about 30 minutes so that the chitosan fiber supporting the graphene is removed. Thus, the graphene fiber was completed.
EXPERIMENTAL EXAMPLE 2
A nylon fiber was formed according to the step S 10 . Nylon-6 powder (Sigma-Aldrich Co. LLC.) was supplied into a formic acid solution and then the formic acid solution including the nylon-6 powder was mixed by a stirrer at 50 degrees Celsius for about 6 hours, thereby forming a nylon solution.
After the formed nylon solution was supplied into the cylinder 21 of FIG. 3 , the nylon solution was electro-spun to the collector 25 under the condition that the applied voltage was 15 kV, a distance between the cylinder 21 and the collector 25 was 10 cm, and a solution injection speed was within a range of about 0.5 ml/h to about 5 ml/h. A nylon fiber having a diameter within a range of several nanometers to several micrometers may be formed according to a spinning condition of a concentration of the nylon solution and the applied voltage. The formed nylon fiber was reacted in a bovine serum albumin (BSA) solution of about 10% concentration for about 30 minutes and then was dried in a hood.
The graphene oxide-containing solution was formed by the same method as described in the Experimental example according to the step S 20 .
The graphene oxide composite fiber was formed according to the step S 30 . After the hydrogen ion concentration (pH) of the formed graphene oxide solution was adjusted at about 4.3, the formed nylon fiber was soaked in the graphene oxide solution having the hydrogen ion concentration (pH) of about 4.3 for about 5 hours. Amide groups formed on the surface of the nylon fiber and hydroxyl groups and carboxyl groups of the graphene oxide were self-assembled to form the composite fiber of a graphene oxide nylon coaxial type. After the formed graphene oxide composite fiber was taken out, the graphene oxide composite fiber was cleaned three times by distilled water and then was dried in a vacuum oven for about 24 hours.
The graphene oxide composite fiber was reduced by the same method as described in the experimental example 1 according to the step S 50 , thereby forming the graphene composite fiber.
The nylon fiber being the supporting fiber was separated from the reduced graphene composite fiber by the same method as described in the experimental example 1 according to the step S 60 . Thus, the graphene fiber was completed.
According to embodiments of the inventive concept, it is possible to easily manufacture the large-area graphene fiber having high strength, high flexibility, and high porosity.
While the inventive concept has been described with reference to example embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the inventive concept. Therefore, it should be understood that the above embodiments are not limiting, but illustrative. Thus, the scope of the inventive concept is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing description.
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A method of manufacturing a graphene oxide composite fiber includes forming a supporting fiber having positive charges thereon; forming a solution containing graphene oxide having a negative charge thereon to provide a graphene oxide-containing solution; coating the supporting fiber with the graphene oxide-containing solution; and permitting self-assembly of the graphene oxide of the graphene oxide -containing solution and the supporting fiber by an attraction between the positive and negative charges to form the graphene oxide composite fiber. The method may include coating the supporting fiber with a solution containing a material having an amine group to provide a positive surface charge on the supporting fiber. The method may include reducing the graphene oxide composite fiber to a graphene composite fiber, such as by one of a thermal reduction method, an optical reduction method, and a chemical reduction method. Large-area graphene fiber structures having high strength, flexibility, and porosity are enabled.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bit line selection decoder, particularly for electronic memories, and to an electronic memory containing such a decoder.
2. Discussion of the Related Art
In an electronic memory, it is sometimes necessary to select one or more of the bit lines of the electronic memory, for example in order to program it. The most obvious solution would be to place a transistor on each one of the bit lines and switch it on, using a control line, when it is necessary to select the respective bit line. Since an electronic memory has a large number of these bit lines, the control lines that switch on the transistors would be too many and would occupy a vast area of the silicon on which the electronic memory is produced.
A current solution is to divide the bit lines into groups, for example including sixteen lines, and to select a particular group by means of a single bit line that is hierarchically higher and is in turn activated by a single transistor. The particular bit line is then selected within the particular group. An example of such a structure is shown in FIG. 1.
A single control line YM0, which is hierarchically higher, activates the bit line A 1 , which leads to the sixteen-line group GR1. Each one of the sixteen lines of the group GR1 is activated by a respective control line YN0-YN15 by means of the respective transistor. It should be noted that in the illustrated example, there are sixteen groups GR1-GR16 (although they are not shown), and therefore hierarchically higher control lines YM0-YM15. In this manner it is possible to create a tree or pyramid structure with a plurality of hierarchy levels.
Finally, the selected bit line can be either programmed by a programming circuit 2 or amplified by an amplifier 3.
Although this solution is efficient, there are a large number of control lines for activating the bit lines. These control lines occupy a considerable area of the chip on which they are integrated, which is undesirable.
Accordingly, a general aim of the present invention is to provide a bit line selection decoder and an electronic memory containing such a decoder which reduces the number of control lines that activate individual bit lines.
SUMMARY OF THE INVENTION
Thus, one object of the present invention is to provide a bit line selection decoder capable of reducing the chip area used for the selection of individual bit lines.
Another object of the present invention is to provide a bit line selection decoder having a relatively low resistive path for the transistors.
Another object of the present invention is to provide a bit line selection decoder that is highly reliable and relatively easy to manufacture at competitive costs.
Accordingly, one aspect of the present invention is a bit line selection decoder for an electronic memory having a plurality of bit lines in a plurality of groups. This bit line selection decoder includes a first set of a plurality of switches, each switch for selecting one of the plurality of bit lines in response to a control signal from a set of control lines applied to each group of bit lines. A second set of a plurality of switches is provided wherein each switch selects one group of the plurality of bit lines. The bit line selection decoder also includes a decoder which has a first input bus of control lines and a second input bus of control lines, wherein the control lines from the first and second input bus address any one of the plurality of groups of bit lines. The decoder has a plurality of outputs, wherein each output drives one switch in the second set of switches.
Another aspect of the invention is an electronic memory containing such a bit line selection decoder which connects a selected bit line to a programming unit, for programming of the selected bit line, or to an amplifier for amplifying any signal on the selected bit line.
In one embodiment, the decoder includes a plurality of modules. Each module has a first input connected to receive one of the control lines from the second bus and a second input connected to receive the control lines of the first bus. It also includes a mechanism for activating a first output according to a combination of the first input and one of the control lines from the second input and a mechanism for activating a second output according to a combination of the first input and another of the control lines from the second input.
In another embodiment, the outputs of the decoder are connected to the second set of switches by points of negligible length.
In another embodiment, the decoder includes a plurality of modules. Each module has a first transistor of a first polarity having a source, a drain connected to a first reference voltage and a gate driven by a first control line of the first bus. A second transistor of the first polarity has a source, a drain connected to the first reference voltage and a gate driven by a second control line of the first bus. A third transistor of the first polarity is connected between the source of the first transistor and the source of the second transistor and has a gate driven by a control line of the second bus. A fourth transistor of a second polarity has a source, a drain connected to the source of the first transistor and a gate. The module has a first output connected to the drain of the fourth transistor and a second output connected to the gate of the fourth transistor. A fifth transistor of the second polarity has a source, a drain connected to the source of the second transistor and the second output, and a gate connected to the first output. A sixth transistor of the second polarity has a source connected to a second reference voltage, a drain connected to the source of the fourth transistor and to the source of the fifth transistors, and a gate driven by the control line of the second bus. The first and second outputs are outputs of the decoder. In this embodiment, a module also may include an eighth transistor of the first polarity connecting the first output and the source of the first transistor and having a gate driven by a third reference voltage. A ninth transistor of the first polarity may connect the second output and the source of the second transistor and has a gate driven by the third reference voltage. The module also may have a tenth transistor of the first polarity connecting the first output and the second output and having a gate driven by a control line of a third bus of control lines. An eleventh transistor of the second polarity is then used to connect the drain of the sixth transistor to the source of the fourth transistor and the source of the second transistor. This transistor has a gate driven by the control line of the third bus. The module also may have a drain stress transistor connected between the first output and the second output and having a gate driven by a drain stress signal.
In another embodiment, the decoder comprises a plurality of modules. Each module includes a NOR gate having a first input for receiving one of the control lines of the first bus, and a second input for receiving one of the control lines of the second bus and an output. A first transistor of a first polarity has a source connected to the output of the NOR gate, a drain and a gate driven by a first reference voltage. An inverter has an input connected to the drain of the first transistor at a node and an output. A second transistor of a second polarity is connected between a second reference voltage and the node and has a gate driven by the output of the inverter. In this embodiment, the module may have a drain stress transistor connected between the node and a third reference voltage, which has a gate driven by a drain stress signal. In this embodiment, the number of modules generally is equal to the number of outputs of the decoder.
In another embodiment, the decoder comprises a plurality of modules. Each module includes a NOR gate having a first input for receiving a control line from the first input bus and a second input for receiving a control line from the second input bus and an output. A first transistor of a first polarity is connected to a first reference voltage and has a gate driven by the output of the NOR gate. An inverter has an input connected to the output of the NOR gate and an output. A second transistor of the first polarity is connected to the first reference voltage and has a gate driven by the output of the inverter. A third transistor of a second polarity is series-connected to a second reference voltage and to the first transistor and a first node and has a gate. A fourth transistor of the second polarity is series-connected to the second reference voltage and to the second transistor at a second node and has a gate connected to the first node, wherein the gate of the third transistor is connected to the second node. In this embodiment the number of modules generally is equal to the number of outputs of the decoder. Additionally, the NOR gate may have a third input for receiving a drain stress signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The characteristics and advantages of the invention will become apparent from the description of several embodiments thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
FIG. 1 is an electrical diagram of a known bit line selection circuit;
FIG. 2a is a view showing the circuit of FIG. 1 according to a different method;
FIG. 2b is a view of another example of a known bit line selection circuit, shown according to the method of FIG. 2a;
FIG. 2c is a view of another example of a known bit line selection circuit, shown according to the method of FIG. 2a;
FIG. 2d is a view of another example of a known bit line selection circuit, shown according to the method of FIG. 2a;
FIG. 3a is a view of the embodiment of the circuit of FIG. 2a with the decoder according to the present invention;
FIG. 3b is a view of the embodiment of the circuit of FIG. 2b with the decoder according to the present invention;
FIG. 3c is a view of the embodiment of the circuit of FIGS. 2c and 2d with the decoder according to the present invention;
FIG. 4a is a partial view of a possible embodiment of the decoder according to the present invention;
FIG. 4b is another partial view of a possible embodiment of the decoder according to the present invention;
FIG. 5 is a partial view of another possible embodiment according to the present invention, provided with two input buses;
FIG. 6 is a view of an improved embodiment of the circuit of FIG. 5; and
FIG. 7 is a view of an embodiment of the circuit of FIG. 5, provided with three input buses.
DETAILED DESCRIPTION
FIG. 2a is a simplified diagram of the circuit of FIG. 1. The plurality of bit and control lines are shown as single buses. The first bus of the control lines comprises the hierarchically higher lines YM<0,15>, whereas the hierarchically lower bit lines are selected by the control lines YN<0,15>. The output is constituted by 256 (16×16) bit lines BL<0,255>, from which a single bit line is selected.
FIG. 2b is a diagram of another possible known bit line selection circuit. There are 32 hierarchically higher control lines YM<0,31> and 16 hierarchically lower control lines YN<0,15>. The output is constituted by 512 (32×16) bit lines BL<0,511>.
FIG. 2c is a diagram of another possible known bit line selection circuit. There are 32 hierarchically higher control lines YM<0,31> and 32 hierarchically lower control lines YN<0,31>. The output is constituted by 1024 (32×32) bit lines BL<0,1023>.
FIG. 2d is a diagram of another possible known bit line selection circuit with three hierarchical levels. There are four hierarchically higher control lines YP<0,3>, sixteen hierarchically intermediate control lines YM<0,15>, and sixteen hierarchically lower control lines YN<0,15>. The output is constituted by 1024 (4×16×16) bit lines BL<0,1023>.
FIG. 3a is a diagram of an embodiment of the present invention which improves on the selection circuit of FIG. 2a.
The bus of the hierarchically higher control lines YM is divided into two buses: a first bus with eight lines YMH<0,7> and a second bus with two lines YML<0,1>. These buses constitute the input of a local decoder 4, the output whereof is constituted by sixteen connection points YM<0,15>. The connections to the transistors that activate a bit line are termed "points", since their length is negligible.
In this manner, the number of control lines for the hierarchically higher lines is reduced by 16-(2+8)=6, since now only ten lines are required to activate sixteen transistors.
FIG. 3b is a diagram of an embodiment of the present invention which improves on the selection circuit of FIG. 2b.
The input of the local decoder 4 is constituted by a first bus with sixteen lines YMH<0,15> and by a second bus with two lines YML<0,1>. The saving is evident. Instead of using thirty-two lines, as in the case of FIG. 2b, it is possible to use only (2+16)=18 control lines.
The number of points YM<0,31> remains 32, which is the same as the number of lines YM<0,31> in FIG. 2b.
FIG. 3c is a diagram of another embodiment of the present invention which improves on the selection circuits of FIGS. 2c and 2d. The decoder 4 now has three input buses: a first one YMH<0,7>, with eight control lines;
a second one YMM<0,3>, with four control lines; and a third one YML<0,1>, with two control lines. The number of points, that is to say, of lines of negligible length that drive the transistors is (2×4×8)=64. In this manner, the number of hierarchically higher control lines is reduced from 64 to 14, with a saving of 50 control lines.
The partial diagram of a possible embodiment of the decoder 4 is shown in FIG. 4a.
This Figure shows only two of sixteen modules composing the decoder of this embodiment. The decoder has two input buses, a high one with eight bits YM<0,7> and a low one with two bits YN<0,1> ("0" in a field of "1"). Each module in this example is composed of a NOR gate 5, with a supply voltage at five volts. The output of the NOR gate 5 is series-connected to a decoupling transistor 6 of the N-channel type, the gate whereof is connected to the five volts supply. The decoupling transistor 6 is furthermore connected to an inverter 7, with a supply voltage at twelve volts. The output of the inverter 7 is connected to the gate of a P-channel transistor 8 interposed between the twelve volts supply and the input of the inverter 7. The input of the inverter is furthermore connected to ground by means of an N-channel transistor 9, called a drain stress transistor, which has the purpose of setting all the outputs of the decoder to logic level "1". This is required when the devices must be controlled to reject weak devices.
When the output of the NOR gate 5 is at five volts, the input of the inverter 7 is at four volts, due to the drain/gate drop of the decoupling transistor 6. In this case, the output of the inverter 7 is brought to zero volts and switches on the P-channel transistor 8, which brings the input of the inverter 7 to twelve volts. The P-channel transistor has the purpose of decoupling the inverter 7 without however causing the inverter to absorb current. The circuit is furthermore configured so as to carry the logic levels defined by zero and five volts to logic levels defined by a higher voltage, e.g. zero and twelve volts, since these levels are used by non-volatile memories.
If the output of the NOR gate 5 is zero volts, the input of the inverter 7 is equally at zero volts, then the output of the inverter 7 is at twelve volts, and the P-channel transistor 8 is off. If one wishes to control the device, the gate of the drain stress transistor 9 is set to logic level "1", so that the output of the inverter becomes logic level "1".
This embodiment uses four transistors of the NOR gate, two transistors of the inverter, and two transistors that are shown (the drain stress transistor is not counted). Therefore, sixteen transistors are used for two modules (two outputs).
Another possible embodiment of the decoder 4 is shown partially in FIG. 4b.
As in the previous case, only two of sixteen modules are shown in the figure. Each module comprises a NOR gate 5 receiving a supply voltage of five volts. The output of the NOR gate 5 is connected to the gate of a first N-channel transistor 10 and to the input of an inverter 11, receiving a supply voltage of twelve volts. The output of the inverter is connected to the gate of a second N-channel transistor 12. The drain of the first transistor 10 is connected to the source of a third transistor 13 of the P-channel type and its source is connected to ground. The drain of the third transistor 13 is connected to a supply voltage of twelve volts. The source of the second transistor 12 is connected to ground and its drain is connected to the source of a fourth transistor 14 of the P-channel type. The drain of the fourth transistor 14 is connected to a supply voltage of twelve volts. The drain of the first transistor 10 is furthermore connected to the gate of the fourth transistor 14 and the drain of the second transistor is connected to the gate of the third transistor 13. The output OUT of the module is provided by the drain of the second transistor 12.
When the output of the NOR gate 5 is at five volts, that is to say, at logic level "1", the output of the inverter 11 becomes zero volts. In this manner, the first transistor 10 is activated, connecting the gate of the fourth transistor 14 to ground. In this manner, the fourth transistor 14 brings the output of the module to twelve volts, whereas the second transistor 12 does not conduct. The third transistor 13 is switched off, since the output OUT is at twelve volts.
Instead, when the output of the NOR gate 5 is at zero volts, that is to say, at logic level "0". the output of the inverter 11 reaches twelve volts and switches on the second transistor 12, whereas the first transistor 10 is switched off. In this manner, the output OUT is set to zero volts by the second transistor 12, which switches on the third transistor 13, which brings the gate of the fourth transistor 14 to twelve volts, so that said fourth transistor does not conduct.
The embodiment of FIG. 4b is better than the embodiment of FIG. 4a in terms of efficiency and decoupling; however, since one module requires four transistors for the NOR gate, two for the inverter, and four transistors, which are shown, twenty transistors are used for two modules.
Both the decoder of FIG. 4a and the decoder of FIG. 4b are not very efficient in terms of saving space on the chip, since to save six control lines one requires 128 transistors and the other requires 160 transistors.
FIG. 5 is a diagram of an improved and preferred embodiment of the decoder 4 according to the present invention.
As in the previous cases, there are two buses with the control lines, a first one YN<0,1> composed of two control lines and a second one YM<0,7> composed of eight control lines.
Both buses have a "1" prevalence, that is to say, all the control lines of a specific bus carry logic level "1" except for one, which selects the bit line and carries logic level "0". Thus, since the first bus YN<0,1> has only two lines, it always has one of the control lines at logic level "0" and the other control line at logic level "1".
This decoder, too, is composed of modules. However, in this case each module produces two outputs of the decoder and therefore only eight modules are needed to provide sixteen output. FIG. 5 shows only two (100 and 101) of the eight modules.
The connections between the buses and each individual module are identical and therefore only the connections to a single module are described.
The first control line of the bus YN<0,1> drives a first N-channel transistor 15, the source whereof is connected to the ground. Likewise, the second control line of the bus YN<0,1> drives a second N-channel transistor 16, the source whereof is connected to ground. The same holds for all the modules of the decoder.
The drains of the first transistor 15 and of the second transistor 16 are connected by means of a third N-channel transistor 17, which is driven by a single control line of the second bus YM<0,7>. The third transistor 17, in each one of the modules, is driven by a single control line of the second bus YM<0,7>.
The drains of the first transistor 15 and of the second transistor 16 are connected to a cross-coupled structure. More specifically, the drain of the first transistor 15 is connected to the source of a fourth transistor 18 of the P-channel type and the drain of the second transistor 16 is connected to the source of a fifth transistor 19, which is also of the P-channel type. The drains of the fourth transistor 18 and of the fifth transistor 19 are connected to the source of a sixth transistor 20 of the P-channel type, which is driven by the same control line of the bus YM<0,7> that drives the third transistor 17. The drain of the sixth transistor 20 is connected to a supply voltage of twelve volts. The source of the fourth transistor 18 is connected to the gate of the fifth transistor 19 and to a first output OUT1. The source of the fifth transistor 19 is connected to a second output OUT2 and to the gate of the fourth transistor 18.
Furthermore, in order to obtain the drain stress effect, there is a seventh transistor 21 of the P-channel type that connects the two outputs OUT1 and OUT2.
All of the gates of the seventh transistors 21 of each of the individual modules are driven by a single line by means of the activation signal DS.
The operation of the decoder according to this embodiment is as follows.
With reference to FIG. 5, assume that the first transistor 15 of the two modules 100 and 101 is controlled by a control line that carries logic level "0" and that the second transistor 16 of the two modules 100 and 101 is driven by a control line that carries logic level "1". Furthermore, assume that the third transistor 17 of the module 100 is driven by a control line that carries logic level "1" and that the third transistor 17 of the module 101 is driven by a control line that carries logic level "0". Likewise, the sixth transistor 20 of the two modules is driven by the same line that drives the third transistor 17.
We first analyze the module 100. The first transistor 15 is off, whereas the second transistor 16 is on, connecting its drain to ground. The third transistor 17 is also on and connects the drain of the first transistor 15 to ground. In this manner, the first output OUT1 and the second output OUT2 are connected to the ground. The fourth transistor 18 and the fifth transistor 19 are on, but the sixth transistor 20 is not, and therefore the twelve volts supply does not affect the outputs of the circuit.
We now consider the module 101. The first transistor 15 is off, whereas the second transistor 16 is on and connects its drain and the second output OUT2 to ground. The third transistor 17 is off and does not connect the drain of the first transistor 15 to ground. The fourth transistor 18 and the sixth transistor 20 are on and bring the first output OUT1 to twelve volts (logic level "1"). The fifth transistor 19 is off and the supply voltage of twelve volts does not affect the second output OUT2, which is connected to ground.
By changing the polarity of the control lines of the first bus YN<0,1>, that is to say, by applying a voltage corresponding to logic level "1" on the first transistor 15 and a voltage corresponding to logic level "0" on the second transistor, the outputs of each module are inverted. By applying the voltage corresponding to logic level "0" to the third transistor 17 and to the sixth transistor 20 of the module 100, one of the outputs of the module 100 would reach twelve volts (of course, the third transistor 17 and the sixth transistor 20 of the remaining modules would have to be activated by a voltage corresponding to logic level "1").
FIG. 6 is a diagram of an improved embodiment of the decoder of FIG. 5.
Each module of the decoder of FIG. 6 is practically identical to the modules of FIG. 5, except that there are an eighth transistor 22, of the N-channel type, placed between the first transistor 15 and the fourth transistor 18, and a ninth transistor 23, of the N-channel type, placed between the second transistor 16 and the fifth transistor 19. The gates of the transistors 22 and 23 are connected to a supply voltage of five volts. The transistors 22 and 23 have a cascaded structure that improves the resistance of the structure to breakdown, since the voltage at the drains of the first transistor 15 and of the second transistor 16 drop to four volts (five volts minus the switch-on threshold of the transistors 22 and 23, which is approximately one volt). In this manner, the voltage at the drains never reaches twelve volts, which might damage the transistors 15 and 16.
FIG. 7 is a diagram of an embodiment with three control line buses.
Apart from the two buses that have already been described earlier, the first one YN<0,1> and the second one YM<0,3>, which now has four control lines, a third bus W<0,3> is now also provided, that is also configured with "0" in a field of "1" and has four control lines. In this manner, the decoder has (2×4×4)=32 outputs or "points", and therefore includes sixteen modules, since each module generates two outputs.
With respect to the configuration of FIG. 5, a tenth transistor 24 of the N-channel type is now provided that connects the outputs OUT1 and OUT2 of each module and is parallel-connected to the third transistor 17. This tenth transistor 24 is driven by a single control line of the third bus W<0,3>.
There is also an eleventh transistor 25 of the P-channel type that is series-connected to the sixth transistor 20. The operation of this embodiment can be deduced from the description of the operation of the embodiment of FIG. 5; however, it can be said that the output OUT1 or OUT2 is selected only in the modules in which the parallel-connected transistors 17 and 24 are driven by a voltage corresponding to logic level "0".
In order to achieve complete decoding, the modules receive as inputs all the possible combinations of the lines of the three buses.
The control lines of the buses that are connected to each module are shown in the following Table 1:
TABLE 1______________________________________MODULE BUS YM<0,3> BUS W<0,3> BUS YN<0,1>______________________________________Module 1 YM0 W0 YN0 and YN1Module 2 YM1 W0 YN0 and YN1Module 3 YM2 W0 YN0 and YN1Module 4 YM3 W0 YN0 and YN1Module 5 YM0 W1 YN0 and YN1Module 6 YM1 W1 YN0 and YN1Module 7 YM2 W1 YN0 and YN1Module 8 YM3 W1 YN0 and YN1Module 9 YM0 W2 YN0 and YN1Module 10 YM1 W2 YN0 and YN1Module 11 YM2 W2 YN0 and YN1Module 12 YM3 W2 YN0 and YN1Module 13 YM0 W3 YN0 and YN1Module 14 YM1 W3 YN0 and YN1Module 15 YM2 W3 YN0 and YN1Module 16 YM3 W3 YN0 and YN1______________________________________
From the above table it is evident how it is possible to provide the progression for decoders having more buses and buses with a different number of control lines.
Finally, in order to achieve the drain stress effect, the signals on the control lines and on the drain stress transistor 21 are set to a voltage corresponding to logic level "0". In this manner, all the outputs of the decoder reach a voltage corresponding to logic level "1".
The foregoing embodiments of the invention reduce the number of control lines that activate individual bit times. In particular, it is noted that for the embodiment of FIG. 5, only six transistors are used for two outputs of the decoder. Therefore, for a decoder having a bus with eight lines YM<0,7> and a bus with two lines YN<0,1>, the total number of transistors is 48, which is much less than the 128 transistors used for the decoder of FIG. 4a and the 160 transistors used for the decoder of FIG. 4b. In this manner, the number of transistors used does not have a strong negative effect on the saving in chip area achieved by reducing the number of control lines.
Furthermore, with reference to FIG. 2d, too many hierarchy levels are avoided, since the decoder according to the present invention allows there to be a smaller number of hierarchical levels of bit lines. In this manner, increasing the dimensions of the bit line selection transistor, which slows the circuit, can be avoided so as to keep the bit line circuit impedance low.
Furthermore, since long control lines are avoided, as shown in FIG. 1, the capacitance of the "points" that drive the selection transistors remains limited, to the benefit of the speed of the circuit.
Finally, in the case of a broken bit line matrix array, that is to say, when a single control line drives two selection transistors in respective symmetrical bit line circuits, since "points" are used instead of control lines for the activation of the selection transistors, the capacitance of these points is low and the points can be used to drive more than one transistor. In this manner, it is possible to increase the dimensions of the selection transistors to decrease the impedance of the bit line circuit.
Having now described an example embodiment of the present invention, it should be apparent that the present invention is susceptible of numerous modifications and variations.
For example, the decoder can be provided dually, that is to say, by inverting the nature of the transistors, the logic levels of the buses and of the supply lines, and of course opposite selection placement.
Finally, all the details may furthermore be replaced with other technically equivalent ones.
In practice, the materials employed, as well as the shapes and the dimensions, may be selected according to requirements of a given design.
Having thus described at least one illustrative embodiment of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention is limited only as defined in the following claims and the equivalents thereto.
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A bit line selection decoder for an electronic memory having a plurality of bit lines in a plurality of groups includes a first set of a plurality of switches, each switch for selecting one of the plurality of bit lines in response to a control signal from a set of control lines applied to each group of bit lines. A second set of a plurality of switches is provided wherein each switch selects one group of the plurality of bit lines. The bit line selection decoder also includes a decoder which has a first input bus of control lines and a second input bus of control lines, wherein the control lines from the first and second input bus address any one of the plurality of groups of bit lines. The decoder has a plurality of outputs, wherein each output drives one switch in the second set of switches. The decoder may include a plurality of modules. Each module has a first input connected to receive one of the control lines from the second bus and a second input connected to receive the control lines of the first bus. The module includes a mechanism for activating a first output according to a combination of the first input and one of the control lines from the second input and a mechanism for activating a second output according to a combination of the first input and another of the control lines from the second input.
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BACKGROUND
There are countless numbers of items and bulk materials which are routinely handled, including agriculture products, municipal solid waste, yard waste, and industrial products. These materials are often loaded into and unloaded from containers having open tops.
Examples include the opens beds of vehicles such as dump trucks, pickup trucks, wagons, railway freight cars, etc. Because of the open nature of the beds, there are also numerous methods and devices for the covering (and uncovering) of these open beds. Covering vehicle beds is necessary to protect the material being hauled from being damaged by objects falling from above as well as to protect innocent passers-by from being injured by material which may inadvertently exit the vehicle bed during transport. Especially useful are flexible sheets of material, such as tarps, which are stretched over the open beds of vehicles. Tarps provide a cheap, effective cover for open vehicle beds and are fairly easy to deploy and stow in a timely manner.
One example for the use of tarps to cover vehicle beds is in the field of landscaping. One concern is the safe transport of tools, topsoil, piping and many other items which frequently need to be delivered to a work site. Another concern arises after the work is complete; many jobs often result in debris which needs to hauled away, such as clippings from trimmed plants (trees, shrubs, grass, etc.), earth, trash, and the like. Because of the dual need of the landscaper to both cover the open bed of his vehicle and easily load and unload material, it would be highly beneficial to combine the two functions, thus enabling him to load and unload diverse material while at the same time deploying or stowing the tarp which is so frequently used in the business.
While there are many devices on the market which do an adequate job of covering and uncovering the load, none attempt to combine the loading/unloading procedures with the deployment/stowing of the tarp. In each case, the material to be hauled is first loaded into the vehicle as a separate step of the hauling process, then the tarp is deployed in some way to cover the vehicle bed. Upon arrival at the work site, the tarp then has to be removed and stowed in some manner before the material can be unloaded. The separate steps of loading and unloading the material takes valuable time which could otherwise be used to accomplish the desired work. In addition, large loads require large tarps which are too bulky and heavy for manipulation by a single operator.
For the foregoing reasons, there is a need for a device and method which combine the functions of deploying and stowing a tarp and the loading and unloading of material to and from a receptacle having an open top, all of which capable of being accomplished by a single operator.
SUMMARY
The present invention allows the loading and/or unloading process to be completed simultaneously with the deployment and/or stowing of a tarp, thus eliminating the additional time needed to perform the steps separately. In the preferred embodiment and method, the top of a first side wall of a vehicle bed has a guide bar attached which extends the length of the side wall and forms a slot between the top of the side wall and the guide bar. A roller arrangement is mounted to a second side wall and functions to roll up the tarp.
To initiate the loading procedure, a tarp of conventional construction is looped over the guide bar, threaded back through the slot, and pulled down the first side wall. The tarp is then fixed to the first side wall by tarp straps or other means. The majority of the tarp is stretched out on the ground along side of the vehicle. The material to be transported is then placed onto the outstretched tarp. The edge of the tarp farthest from the vehicle is then pulled back over the material, over the open bed, and attached to the roller. The roller is then rotated, preferably driven by an electric motor which is mechanically linked to the roller via conventional means. As the roller rotates, the tarp is wound onto the roller, consequently pulling the material up and over the first side wall into the vehicle bed. The rotation of the roller is stopped when the tarp is stretched taut across the open top of the vehicle bed. The material may then be hauled in an ordinary way with no risk to either the material or the general public.
In an alternate embodiment of the present invention, the device is configured such that a loading and unloading procedure may be incorporated with the deployment and stowing of the tarp. In this instance, the structure of the apparatus is similar to the preferred embodiment except that the roller is mounted on a pair of pivot arms which are attached to the second side wall of the vehicle, on which the guide bar is also mounted. The pivot arms are of sufficient length so that when in the substantially horizontal "load" position, the roller itself is located near the top of the first side wall. The tarp is then manipulated such that one portion is stretched out on the ground along side the vehicle (as in the previously described loading process), the middle portion is draped across the floor of the vehicle bed, and one edge of the tarp is fed through the slot formed by the guide bar and the top of the second side wall. The edge of the tarp is then secured to the second side wall. The material to be loaded is placed onto the portion of the tarp stretched out on the ground in a manner identical to that described above. The roller is rotated (again, preferably driven by an electric motor). As the tarp is wound onto the roller, the pivot arms allow the roller to follow the bulk of the material as it passes over the first side wall and into the bed. After the material is deposited into the vehicle bed, the far edge of the tarp is unattached from the side wall and attached to the roller. The roller is rotated once more. The tarp is drawn tighter together and the material is compressed within the tightened tarp in the vehicle bed. The load is now stable and secure in the bed, ready to safely transport.
The unloading procedure is as follows. The roller is rotated such that a portion of the tarp is unwound from the roller. The pivot arms are then locked into an upright "unload" position. The unwound portion of the tarp is fed through the slot and attached to the second side wall. The roller is again rotated. As the tarp is wound back onto the roller, the material to be unloaded is lifted up along the second side wall by the tarp and is ultimately lifted over the second side wall and out onto the ground adjacent to the vehicle. The tarp is unattached from the second side wall and wound up completely onto the roller. If needed, the edge of the tarp can be attached to the first side wall instead of the second, allowing the material to be unloaded over the first side wall instead of the second. The pivot arm assemblies can then be returned to the "load" position and the vehicle is ready for the next work assignment.
Accordingly, it is an object of the present invention to provide a means for handling materials which combines the loading and unloading processes with the deployment and stowing of a tarp.
It is a further object of the present invention to provide the above-described means for handling materials which is safe, easy to use, efficient, and capable of being managed by a single operator.
For a further understanding of the present invention and the objects thereof, attention is directed to the drawings and the following brief description thereof, to the detailed description, and to the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of the present invention mounted on a vehicle;
FIG. 2 is rear elevational view of an embodiment of the present invention mounted on a vehicle with the tailgate removed showing one step in the loading process;
FIG. 3 is rear elevational view of an embodiment of the present invention in the operational mode mounted on a vehicle with the tailgate removed showing another step in the loading process;
FIG. 4 is an expanded perspective view of the second side wall and the roller assembly of the preferred embodiment of the present invention;
FIG. 5 is an expanded top plan view of a section of the roller assembly of the preferred embodiment of the present invention;
FIG. 6 is an expanded perspective view of a section of the near wall and guide rail assembly of the preferred embodiment of the present invention;
FIG. 7 is a perspective view of an alternate embodiment of the present invention mounted on a vehicle.
FIG. 8 is an expanded perspective view of the primary pivot arm assembly of the alternate embodiment.
FIG. 9 is a further expanded view of the clutch assembly mounted on the primary pivot arm assembly of the alternate embodiment.
FIG. 10 is a rear elevational view of the alternate embodiment showing one step in the loading process.
FIG. 11 is a rear elevational view of the alternate embodiment showing another step in the loading process.
FIG. 12 is a rear elevational view of the alternate embodiment showing yet another step in the loading process.
FIG. 13 is a rear elevational view of the alternate embodiment showing the final step in the loading process.
FIG. 14 is a rear elevational view of the alternate embodiment showing one step in the unloading process.
FIG. 15 is a rear elevational view of the alternate embodiment showing the final step in the unloading process.
DETAILED DESCRIPTION
Tarp loader 100, shown in FIG. 1, includes tarp 200, receptacle 300, roller assembly 400, motor arrangement 500, guide bar assembly 600, and other associated components.
Tarp 200 is a flexible sheet having generally constant dimensions. It may be constructed of a woven textile material, coated or uncoated, or can be an extruded sheet of plastic material, or the like. Tarp 200 includes near edge 202, far edge 204, front edge 206, and rear edge 208. Vehicle bed 300 is the compartment in which material is hauled, and is defined by first side wall 302, second side wall 304, front wall 306, rear wall 308, and floor 310. Rear wall 308 may be a conventional tailgate, hinged either at its bottom or one side, for traditional loading and unloading from the rear of the vehicle. Vehicle bed 300 is open at the top.
Roller assembly 400, best shown in FIGS. 4 & 5, includes roller brackets 401, roller 405, roller drum 410, and roller sprocket 420. Roller 405 is mounted between roller brackets 401, one of which is mounted on the top of second side wall 304 near front wall 306 and the other of which is mounted on the top of second side wall 304 near rear wall 308. Roller drum 410 is axially connected to roller 405, which in turn is axially connected to roller sprocket 420.
Roller 405 is driven by motor 510 which is mechanically linked to roller 405 by gearbox 512 and roller sprocket 520. Motor 510 is electrically connected to motor controls 520 via wiring 515.
Guide bar assembly 600, best shown in FIG. 6, includes guide bar 605 and guide bar brackets 610. Guide bar 605 is mounted to guide bar brackets 610, one of which is mounted on the top of first side wall 302 near front wall 306 and the other of which is mounted on the top of first side wall 302 near rear wall 308. Slot 615 is formed between guide bar 605 and the top of first side wall 302.
To begin the loading operation as shown in FIGS. 2 & 3, tarp 200 is spread out flat on the ground immediately adjacent to first side wall 302 of vehicle bed 300. Near edge 202 of tarp 200 is pulled by hand over guide bar 605, threaded back through slot 615, and draped down along the outside of first side wall 302. Near edge 202 of tarp 200 is then secured to the outside of first side wall 302 with tarp straps 220 and tie-down hooks 320 or the like, best shown in FIG. 6.
Ropes or other lines may be used to assist in winding up tarp 200 onto roller 405 so that excessively long tarps may be avoided. In the preferred embodiment, for example, front line 207 is attached to the corner of tarp 200 formed at far edge 204 and front edge 206, preferably secured to a front grommet (not shown) sewn into tarp 200. Similarly, rear line 209 is attached to the corner of tarp 200 formed at far edge 204 and rear edge 208, preferably secured to a rear grommet (not shown) sewn into tarp 200. Front line 207 extends from the front grommet (not shown) to roller 405 near front wall 306, is threaded through hollow roller 405, and wound around roller drum 410, best shown in FIGS. 4 & 5. Rear line 209 extends from rear grommet (not shown) directly to roller drum 410.
To operate the tarp loader as shown in FIGS. 2 & 3, material 999 is placed onto the surface of tarp 200. The operator first ensures that front and rear lines 207 and 209 are started on roller drum 410. The operator starts motor 510 at control panel 530 causing roller 405 to wind up front and rear lines 207 and 209. Far edge 202 of tarp 200 is pulled over material 999, over first side wall 302, across truck bed 300 to roller 405. As roller 405 continues to wind up tarp 200, material 999 is lifted up and over first side wall 302 by tarp 200, and is ultimately deposited onto floor 310 of vehicle bed 300. The operator halts the rotation of roller 405 when tarp 200 is stretched taut across the top of vehicle bed 300. Material 999 may then be hauled in a conventional manner with no risk to either the material or the general public.
In an alternate embodiment, shown in FIGS. 7-15, the tarp loader is constructed such that both a loading and unloading operation is possible. The device is similar to that previously described with the exception of roller 405 configuration and placement.
The alternate embodiment utilizes primary pivot arm assembly 700 in conjunction with roller 405, best shown in FIG. 8. Lower end 701 of primary pivot arm assembly 700 is mounted to second side wall 304. Mounting angle 711 is welded or otherwise attached to second side wall 304 and primary pivot arm support 710 is attached to mounting angle 711. Two primary pivot arm members 720 are attached to primary pivot arm support 710 such that primary pivot arm members 720 are rotatable about pivot point 702. Primary pivot arm stop (not shown) is attached to primary pivot arm member 720 and abuts an external cab bulkhead (not shown) when primary pivot arm assembly 700 is in the "load" position.
A dampening system is provided to mitigate a free-fall of primary pivot arm assembly 700. Pivot arm piston 761 slidably engages pivot arm cylinder 760 which contains adjustable snubber spring 762. As primary pivot arm assembly 700 pivots downward due to gravity, snubber spring (not shown) is stretched, thus dampening the downward movement, ultimately avoiding damage to equipment due to excessive impact. Snubber spring 762 can be adjusted to provide the correct force necessary to dampen but not entirely prevent the movement of primary pivot arm assembly 700.
Motor arrangement 750 is mounted to primary pivot arm members 720 using motor support 752. Motor 751 is connected to gear box 758, which in turn is connected to drive gear 756, which engages drive chain 754. Motor control 775 may be mounted on the exterior of the vehicle, as described in the previous embodiment, or may be connected to a power source inside the cab of the vehicle, as depicted in FIG. 7, and fitted with flexible cord 776 for remote use.
Clutch assembly 740 allows roller 405 to be functionally disconnected from drive chain 754 for maintenance or other situations when it is necessary for roller 405 to spin freely. Clutch assembly 740 is mounted at upper end 703 of primary pivot arm assembly 700, best shown in FIG. 9, and is a standard jaw clutch arrangement. Clutch lever 744 is mounted to cross member 746 by welding, bolting, or equivalent means. Clutch lever 744 retains outboard clutch disc 745, which is fixed to roller axle 406. Inboard clutch disc 741 is fixed to clutch sprocket 742, both of which rotate freely about roller axle 406. Roller bearing 748 facilitates the rotation of roller axle 406 as it passes through an opening in primary pivot arm member 720. To disengage drive chain 754 from roller 405, clutch lever 744 is urged away from roller and outboard clutch disc 745 disengages from inboard clutch disc 741. To engage drive chain 754 with roller 405, clutch lever is urged toward roller 405 until outboard clutch disc 745 engages inboard clutch disc 741, thus allowing the power of drive chain 754 to be transferred to roller 405.
Primary pivot arm safety covers 730 are attached as shown in FIG. 8 to prevent injury to operators and to avoid damage to pivot arm components from falling debris.
Secondary pivot arm assembly 800, shown only in FIG. 7, is similar in its structure to primary pivot arm assembly 700 except that there is no motor arrangement 750 or clutch assembly 740. Mounting angle (not shown) is welded or otherwise attached to second side wall 304 and secondary pivot arm support 810 is attached to mounting angle (not shown). Two secondary pivot arm members 820 are attached to secondary pivot arm support 810 such that secondary pivot arm members 820 are rotatable about pivot point 802. Secondary pivot arm safety covers 830 are attached to prevent injury to operators and to avoid damage to pivot arm components from falling debris.
Guide bar assembly 600 is securely mounted on second side wall 304 in a manner identical to that described in the previous embodiment.
For increased hauling capacity, optional folding extension panels (not shown) may be used. Extension panels are approximately the same size as the four walls of vehicle bed 300 and are hingedly attached to the top of each of the four walls. When increased hauling capacity is needed, the four extension panels are swung up and locked in place by suitable fastening means (not shown). When increased hauling capacity is not needed, the four extension panels are folded down and secured to the respective walls of vehicle bed 300.
The loading operation is as follows, shown in FIGS. 9-13. Primary and secondary pivot arm assemblies 700 and 800 start in the substantially horizontal "load" position, with a primary pivot arm stop (not shown) resting on an external cab bulkhead (not shown). Primary and secondary pivot arm members 720 and 820 are of sufficient length so that when they are in the "load" position, roller 405 is positioned proximate to the top of first side wall 302. Tarp 200 is manipulated, either manually (using the clutch assembly 740 to disengage drive chain 754 from roller 405) or by driving roller 405 with motor arrangement 750, such that one portion is stretched out on the ground adjacent first side wall 302 (as in the previously described loading process) and the middle portion is draped across floor 310 of vehicle bed 300. Near edge 202 of tarp 200 is fed through guide slot 615 and secured to the outside of second side wall 304 via tarp straps 220 and tie-down hooks 320. As an alternate means for securing near edge 202 to second side wall 304, a dowel rod and pocket combination may be used. Dowel pocket 251 is sewn into tarp 200 proximate to and running along near edge 202. After near edge 202 is fed through slot 615, dowel rod 250 having a diameter greater than the width of slot 615 is inserted into dowel pocket 251, thus preventing tarp 200 from being pulled back through slot 615 in the direction toward near wall 302.
Material 999 to be loaded is placed onto the upper surface of tarp 200 stretched out on the ground in a manner identical to that described above. Far edge 204 of tarp 200 is then pulled over material 999 and attached to roller 405 via a hook-and-loop arrangement or equivalent. The operator starts motor 751 using motor control 775 which may be connected to a power source (not shown) in the cab of the vehicle or mounted on the exterior of the vehicle. Motor arrangement 750 propels drive chain 754 which engages clutch sprocket 742 and roller 405 is rotated in a manner identical to that described above for the preferred embodiment of the present invention. As tarp 200 is wound onto roller 405, primary and secondary pivot arm assemblies 700 and 800 rotate up about pivot points 702 and 802, respectively, allowing roller 405 to follow the bulk of material 999, which is encased in tarp 200, as it passes along and then over first side wall 302 and into vehicle bed 300. After material 999 is deposited into vehicle bed 300, rotation of roller 405 is halted. Near edge 202 of tarp 200 is unattached from the outside of second side wall 304 and reattached to roller 405. Rotation of roller 405 is again initiated and tarp 200 is drawn tighter together and material 999 is compressed within the tightened tarp 200 in vehicle bed 300. The load is now stable and secure in bed 300, ready to safely transport.
The unloading procedure is as follows. Near edge 202 is freed from roller 405, motor arrangement 750 is activated and roller 405 is rotated such that a portion of tarp 200 is unwound from roller 405, then motor 751 is stopped. Taking advantage of the slack created in tarp 200, primary and secondary pivot arm assemblies 700 and 800 are then pivoted up and away from the "load" position and locked in the upright "unload" position using pivot arm lock 725 which engages pivot arm lock pins 726 to hold pivot arm assembly 700 in place (an identical lock, not shown, is used on secondary pivot arm assembly 800). Near edge 202 of tarp 200 is then fed through guide slot 615 and is again temporarily attached to the outside of second side wall 304 using a hook-and-loop arrangement or equivalent. The operator again starts motor 751 and roller 405 is again rotated. As tarp 200 is wound back onto roller 405, material 999 is lifted up along second side wall 304 by tarp 200 and is ultimately lifted over second side wall 304 and ejected onto the ground adjacent to the vehicle. After material 999 is unloaded, motor 751 is stopped and near edge 202 of tarp 200 is unattached from second side wall 304. The operator starts motor 751 and continues to rotate roller 405 until tarp 200 is completely wound onto roller 405 and fastened securely thereupon.
If it is desirable to unload material 999 over first side wall 302 instead of second side wall 304, a simple change is required. Instead of attaching near edge 202 of tarp 200 to the outside of second side wall 304 and attaching far edge 204 to roller 405, the reverse is done: far edge 204 of tarp 200 is attached to the outside of first side wall 302 and near edge 202 is attached to roller 405. With the situation reversed as described, roller 405 winds up tarp 200, ultimately carrying material 999 up and over first side wall 302.
After unloading is complete, the vehicle is then ready, with stowed tarp, for the next job assignment.
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The preferred embodiment of the present invention contemplates a tarp loader and related method, that is, a device which deploys a tarp to cover a receptacle having an open top, e.g., an open vehicle bed, while simultaneously loading various materials into the receptacle. The material to be loaded is placed on the surface of the tarp and the tarp is then wound onto a roller. As the tarp is wound onto the roller, the tarp carries the material up and over the side wall of the receptacle. The loading procedure is complete when the tarp is stretched taut across the open top of the receptacle. In an alternate embodiment, the tarp loader is configured so that a loading and unloading operation are both possible. As the tarp is deployed, material is carried into the receptacle as the tarp is wound onto a roller which is mounted on a pair of pivot arms. For unloading, the tarp is again wound on the roller, the tarp carrying the material up and over the side wall of the receptacle and depositing it adjacent thereto.
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BACKGROUND OF THE INVENTION
This invention concerns an automatic gunning apparatus for the repair of metallurgical furnaces which has a detachably mounted gunning pipe. More specifically, it concerns an automatic gunning apparatus for repairing the refractory lining of metallurgical furnaces such as converters and electric furnaces, the whole apparatus being compact and so designed that the gunning pipe can be freely attached and detached.
Conventionally, the repair by gunning pipe of the amorphous refractory lining of converters and electric furnaces used for steelmaking has been carried out by the following methods:
(1) Insertion of a gunning pipe into the furnace by a skilled operator who carries out the gunning operation manually, or
(2) Operation by remote control of an automatic gunning apparatus equipped with a gunning pipe which is water cooled and which has a mechanism for elongating and contracting the pipe.
In method (1), i.e., manual repair, the operator must carry the heavy gunning pipe for a long period of time in order to insert it into the furnace at high temperature and perform the gunning operation under high temperature conditions, which requires great muscular effort.
In method (2), the apparatus is usually mounted on a self-propelled vehicle, the gunning pipe being water cooled and having a mechanism by which it can be elongated or contracted, so that the gunning operation can be performed by remote control. In this case, however, the apparatus is bulky, while the mechanism is complex and costly. In particular, although the gunning pipe has a mechanism by which it may be elongated or contracted, its overall length when contracted is still considerable, so its manipulation, operation and control in a narrow space is complicated and requires experience. Further, a large space is required to store the apparatus when it is on standby for operation. In addition, although the gunning pipe is enclosed in a water-cooled tube, it deforms due to wear and heat and often has to be replaced. The replacement operation, moreover, is tedious and requires a great deal of preparation.
The present invention therefore aims to solve these problems inherent in the prior art. More specifically, it aims to provide an automatic gunning apparatus of simple structure for repairing metallurgical furnaces which has a detachably mounted gunning pipe and which can accommodate a gunning pipe of simple structure such as the gunning pipe generally used for manual repair operations in the past.
A further object of the present invention is to provide an automatic gunning apparatus for repairing metallurgical furnaces which has a detachably mounted gunning pipe, wherein the gunning pipe can be freely mounted and detached, the pipe being mounted on the apparatus at the beginning of the gunning operation, the operation being carried out by remote control, and the pipe detached from the apparatus when the operation has been completed.
SUMMARY OF THE INVENTION
The automatic gunning apparatus for repairing metallurgical furnaces described in the present invention comprises means for supplying refractory material to effect the repair; a detachably mounted gunning pipe fitted to the supply means; a pair of pinch rollers for moving the gunning pipe forward along its axis; a rotating drum through which the gunning pipe passes and which encloses the gunning pipe; means for rotating the drum about its axis; a platform supporting the drum rotating means; a column bearing the platform; means for tilting the platform; and a support fixture for the pinch rollers rigidly connected to the drum such that the gunning pipe is axially rotated by the rotation of the drum.
In preferred forms of the present invention, the column includes means for rotating the column about its axis; the pair of pinch rollers which move the gunning pipe forward in the axial direction are arranged such that they have an axis perpendicular to the axis of the gunning pipe; either one or both of the pinch rollers is easily removed or released by a spring mechanism; the drum rotating means includes a plurality of drive rollers which are in close contact with the drum such that their axes are parallel to the axis of the drum; and a portion of the circumference of the drum can be opened to insert the gunning pipe in the drum. Any of the platform, column and support fixture, alone or in combination, may be provided with a shield for protecting the apparatus from heat or flame such that the shield is either integral with or mutually engageable with its supporting unit of the apparatus.
The gunning pipe of the present automatic repair apparatus may be that which is usually used for manual repair of furnaces, while the repair apparatus may be transported by forklift, mounted on a moving pallet, self-propelled, or of a type which can be suspended from a crane.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the automatic gunning apparatus of the present invention will become evident from the following detailed description of embodiments thereof in conjuction with the accompanying drawings wherein like reference numerals indicate like structure throughout the several views.
FIG. 1 and FIG. 2 are, respectively, a side elevational view and a rear elevational view, shown in partial cross section, of a preferred embodiment of the automatic gunning apparatus with detachably mounted gunning pipe of the present invention; and
FIG. 3 and FIG. 4 are, respectively, a side elevational view and a rear elevational view, shown in partial cross section, of a second preferred embodiment of the present automatic gunning apparatus.
DETAILED DESCRIPTION OF THE INVENTION
The gunning apparatus is shown with a gunning pipe 1 installed. As shown in FIGS. 1-4, gunning pipe 1 is connected to a mixer 5 by means of a swivel joint 3. A material feed hose 7 and a water feed hose 9 are connected to mixer 5, in which water and the refractory material for effecting the repair are mixed. The water supply to mixer 5 is controlled by a valve 11.
The gunning apparatus of the embodiment shown in FIGS. 1 and 2 has a support platform 21, equipped with a pair of pinch rollers 13 and a pair of receiving rollers 17 and 19. More specifically, pinch rollers 13 have an axis perpendicular to the axis of gunning pipe 1 and consist of either two drive rollers or one drive roller and one idle roller. Preferably, in the latter case, the idle roller can be freely attached and detached together with gunning pipe 1, and can also be easily removed when mounting or detaching the pipe.
Receiving rollers 17, 19 are installed to the front of platform 21. The upper roller 17 can be spring released to the position shown by the dotted line in FIG. 1 so that when fitting gunning pipe 1 with gunning nozzle 51, or removing it from the apparatus, gunning pipe 1 can be passed through drum 25 and positioned on fixed roller 19.
A cover 27 is fitted to platform 21 and houses drum 25. As shown in FIG. 2, drum 25 is supported by four pressure rollers 31, and is rotated by an axial drive gear 29'. Gear 29' is driven clockwise or counterclockwise, as required by the gunning operation, by a motor (not shown in the drawing). A handle 35 controls the rotating speed of drum 25.
As shown in FIG. 1, an arm 37 extends forward from platform 21, fixed receiving roller 19 being held at the tip of arm 37. As described above, spring-loaded receiving roller 17 is positioned above fixed receiving roller 19 and rotates in unison with fixed receiving roller 19 so as to grip gunning pipe 1.
Platform 21 is supported by a column 41 through pin 39, and is also supported by one end of electric cylinder 43 which is joined at its other end to column 41. Platform 21, therefore, tilts about pin 39 in accordance with the elongation and contraction of cylinder 43.
Column 41 is mounted on boom platform 45 such that it can rotate, being provided with a worm gear 47. Worm gear 47 engages with worm 49, and when worm 49 turns, column 41 rotates.
Each of arm 37, column 41 and boom platform 45 can include a shield 53, 55, either integrally attached to the apparatus or engagable with its supporting means when needed during a gunning operation. As shown in FIGS. 1 and 2, shield 53, positioned so as to protect cover 27 and column 41, is attached to the apparatus through pin 39, includes side folds 53', and has an opening through which gunning pipe 1 can pass.
The action of the automatic gunning apparatus of the present invention described above is as follows:
Firstly, either one or both of pinch rollers 13, and receiving roller 17, are spring released, following which gunning pipe 1 is passed through drum 25 from its rear end and positioned on receiving roller 19. Gunning pipe 1 is then gripped by pinch rollers 13 and receiving roller 17 is moved down, so that the pipe is finally held by pinch rollers 13 on either side and by receiving roller 19, respectively.
Gunning pipe 1 is moved in the direction of its axis by the rotation of pinch rollers 13. Gunning pipe 1 can also be rotated about its own axis by driving the rotating gear 29'. When gear 29' is rotated, drum 25 rotates, and a plate 23 which supports pinch rollers 13 and is fixed to drum 25 rotates together with the drum. Gunning pipe 1, which is held by pinch rollers 13, therefore rotates, and so does gunning nozzle 51 which is attached to the end of gunning pipe 1.
Gunning pipe 1 can also be tilted about pin 39. This can be done by elongating or contracting electric cylinder 43 so as to tilt platform 21.
In addition, gunning pipe 1 can be rotated about column 41 by means of worm gear mechanism 47, 49. When worm 49 is rotated, column 41, which is equipped with a worm gear 47 that engages with worm 49, rotates on its own axis; thus gunning pipe 1 also rotates about this axis. Further, when gunning pipe 1 is rotated about column 41, shield 53 functionally attached to the pipe also rotates. On the other hand, shield 55 protecting platform 45 remains steady.
It is of course to be understood that pinch rollers 13, drive gear 29', electric cylinder 43 and worm 49 can be operated by remote control.
A second preferred embodiment of the automatic gunning apparatus of the present invention is shown in FIGS. 3 and 4. While this gunning apparatus operates basically the same as the apparatus of FIGS. 1 and 2, there are slight differences in the apparatus and its operation which are described below.
The gunning apparatus of FIGS. 3 and 4 has a support platform 21 equipped with a pair of pinch rollers 13 and 15 and a pair of receiving rollers 17 and 19. The upper rollers 13 and 17 are of the spring-loaded type, and spring out when mounting or detaching gunning pipe 1. Roller 15 on the lower, fixed side is motor driven and is mounted on supporting plate 23. Plate 23 is fixed to drum 25 and rotates together with it.
On platform 21, an upper release cover 27 is mounted which houses drum 25. As shown in FIG. 4, drum 25 is supported by two axial rotation drive rollers 29, and is rotated while being held by pressure rollers 31 which move in unison with drive rollers 29. Drive rollers 29 are themselves rotated by means of a gear 33 driven by a motor not shown in the drawing. Further, a portion 25a of the circumference of drum 25 can be opened by a spring release to insert gunning pipe 1 in the drum, after which drum 25 may be closed to reform a smooth cylindrical drum surface.
Column 41 is mounted vertically on boom platform 45 such that it can rotate, and is provided with a worm gear 47. Worm gear 47 engages with worm 49, and when worm 49 turns, column 41 rotates.
To insert gunning pipe 1 in this apparatus, the upper pinch roller 13, the spring plate 25a of drum 25 and receiving roller 17 are first released. With the apparatus so arranged, gunning pipe 1 is inserted into drum 25 through the open space left by spring plate 25a, then positioned on pinch roller 15 and receiving roller 19. Following this, upper pinch roller 13 and receiving roller 17 are moved down so that gunning pipe 1 is gripped by lower pinch roller 15 and receiving roller 19, and spring plate 25a of drum 25 is closed.
To detach gunning pipe 1, spring plate 25a of drum 25 is released, upper pinch roller 13 and receiving roller 17 are released and, after opening up the whole apparatus above gunning pipe 1, the latter is removed from the open part of drum 25.
Gunning pipe 1 is moved in the direction of its axis by the rotation of pinch roller 15. Pinch roller 15 moves in unison with upper roller 13 so as to grip gunning pipe 1, and when pinch roller 15 is rotated, gunning pipe 1 moves forward or backward according to the direction of rotation. Gunning pipe 1 can be rotated about its own axis by driving the axial rotation drive roller 29. When drive roller 29 is rotated, rotating drum 25 rotates. Plate 23, which supports pinch rollers 13 and 15, is fixed to drum 25 and rotates with it. Gunning pipe 1, which is gripped by pinch rollers 13 and 15, therefore rotates, and so does gunning nozzle 51 at the end of gunning pipe 1.
Gunning pipe 1 can also be tilted about pin 39. This can be done by elongating or contracting electric cylinder 43 so as to tilt platform 21.
In addition, gunning pipe 1 can be rotated about column 41 by means of the worm gear mechanism 47, 49. When worm 49 is rotated, column 41, which is equipped with a worm gear 47 that engages with worm 49, rotates on its own axis; thus gunning pipe 1 also rotates about this axis.
It is of course to be understood that fixed pinch roller 15, drive roller 29, electric cylinder 43 and worm 49 can be operated by remote control.
As can be seen from the above description of the automatic gunning apparatus of the present invention, the gunning pipe used for applying refractory material can be freely mounted on or detached from the apparatus, while the apparatus itself has a simple structure which permits movement of the gunning pipe along the axis of the pipe, rotation about the axis of the pipe, tilting, and rotation about a support axis. In particular, the apparatus can accommodate gunning pipes which have normally been used for manual repair operations in the past, and requires no extra equipment outlay.
The automatic gunning apparatus of the present invention, moreover, is compact. It can be transported by forklift, mounted on a moving pallet or on a platform with wheels as a self-propelled moving vehicle, or suspended from the roof by a crane.
Finally, the automatic gunning apparatus of the present invention can be used for repairing converters, electric furnaces and smelting furnaces, or for repairing the refractory lining of various types of tundishes and refining pans.
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An automatic gunning apparatus for repairing metallurgical furnaces includes a device for supplying refractory material to effect the repair; a detachably mounted gunning pipe fitted to the supply device; a pair of pinch rollers for moving the gunning pipe forward along its axis; a rotating drum through which the gunning pipe passes and which encloses the gunning pipe; a plurality of rollers for rotating the drum about its axis; a platform supporting the rollers; a column bearing the platform; a device for tilting the platform; and a support fixture for the pinch rollers rigidly connected to the drum such that the gunning pipe is axially rotated by the rotation of the drum.
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FIELD OF THE INVENTION
The present invention relates to the technology of manufacturing of composite wooden tiles, e.g. splint slabs, aslant sawed panel blocks, plank panels etc. These articles are usually made of a wood off-cut component shaped together with a laminating component and a binder in the form of a flat board. Such articles are used mainly for decorative purposes, for example as a parquet, decorative wall panels, furniture panels and so on.
More particularly the present invention refers to manufacturing of such articles by a process of utilizing the wood off-cut component, reducing the consumption of the binder and the laminating component and improving the decorative quality of the final product. By virtue of more efficient consumption of the off-cut component and reduced, consumption of the binder component the process of manufacturing in accordance with the present invention has improved ecological cleanliness.
BACKGROUND OF THE INVENTION
Wood has always been and still remains the preferable construction material that provides for ecological cleanliness and comfort of the premises. However, wood has became less available at mass civil engineering because of its high cost that still does not allow to manage without the use of splint slabs, wooden fiber plywood and other products made with the use of binders based on formaldehyde containing resins. It is therefore desired to recycle the major part of the wood which is inevitably lost during the wood processing.
As it is known, the wood mechanical properties possess anisotropy, i.e. such wood properties like strength, wear resistance, elasticity etc. are dissimilar along and across the fibers. Moreover, the decorative features of the wood structure along the transversal and longitudinal cuts (wood cross-cut and wood rip-cut respectively) are also substantially different. These structure differences are associated with the fact that psychologically the human perception of a perfect object is based on its subconscious examination and comparison with the stereotype. From this stand point a surface unit of a wood cross-cut is esthetically advantageous since it is more attractive than that of a rip-cut and this fact enables using of small elements derived from the crosscut wood sections for creating a variety of decorative compositions which impart the final product attractive and natural appearance.
The above provides a basis for the novel approach to the issue of utilizing of wood off-cut wastes which is implemented by the present invention, i.e. utilizing of small off-cut units in the form of slices having certain diameter and height.
In accordance with the invention it is suggested to use such slices to form a face side of a composite wooden tile e.g. a splint-slab or decorative panel. Utilization of off-cut slices facilitates manufacturing of wooden tiles and allows producing of tiles with cery attractive decorative appearance.
The slices are prepared by sawing of the wood off-cuts (knots, substandard saw cuts etc.) to small slice units with equal heights. The slice units are assembled into a pattern to form a face layer of the article. For preparation of slices one can use not only commercial wood off-cuts but also fruit and decorative trees off-cuts. The use of wooden wastes resulting from the processing of various kinds of trees having different colors spectra and variety of the structure of their cross-section enables wide range of decorative combinations especially suitable for design of decorative wooden tiles.
The idea of using the structure of wooden cross-cuts for formation of the face side of a wooden tile has been conceived long time ago. The most explicit example of the use of wood cross-cuts (taking into account that wear resistance of the wood cross-cut is also better that that of the rip-cut) was the use of vertically fit logs in pavements in ancient Russian cities.
In the last decades the wood working industry has shown interest to the use of wood crosscut elements. In German patent DE2355925 there is disclosed the using of rectangular cross-cuts as a basis for the parquet floors. In Russian patent SU 1642957 it is disclosed the use of wooden slices to prepare a basis assembled from splint-slabs or other wood materials. The wooden inserts with equal diameter were glued to the slab's basis to form its face side. The assembled slab was polished and coated with a lacquer. The ready tiles having 500×500 mm size were used as parquet and as decorative panels. The disadvantage of this method is associated with the necessity in time consuming manual gluing of slices.
In Russian patent SU1761908 is disclosed a method of manufacturing of splint slabs in which the wood slices are laid to fit close to each other and the gaps between them is filled with a binder made of a resin based either on oligomers or polymers. The shortcoming of this method is associated with the fact that the bending strength of the ready article is strongly dependent on the binder strength. Furthermore, since the slabs are prepared from dissimilar materials the surface roughness of the ready slabs after polishing becomes heterogeneous and this deteriorates the esthetic appearance of the ready tile.
In Russian patent application 504901/15 of 1992 it is suggested to manufacture wooden boards assembled from butt end slices having two different diameters and of dedicated inserts which should be suitable for filling the free space between the adjacent slices. This method is time and labor consuming since it requires preparation of dedicated inserts, enlarging the space between the adjacent slices and manual placement of the inserts between the slices. Since this method employs only slices with particular diameter the utilization of wooden cross-cuts is limited. Furthermore, esthetically the articles prepared by this method are less attractive since the inserts situated between the large crosscut slices deteriorate the contiguity of their natural pattern.
Therefore it can be seen that despite the existence of various methods for manufacturing of composite wooden tiles from wood off-cut slices there is still felt a need for a new and improved manufacturing method which will sufficiently reduce or overcome the shortcomings of the prior art methods.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide a new method of manufacturing of decorative wooden composite tiles from wood cross-cut slices which improves utilization of crosscut wastes and thus improves the recycling of wooden wastes associated with the wood processing technology.
The further object of the invention is to provide a new and simple manufacturing method enabling producing of wooden tiles from wooden slices without the necessity of manual filling the intervals between adjacent slices.
Still further object of the invention is to provide a new manufacturing method enabling to reduce the consumption of the laminating component and the binder component in the ready article.
The other object of the invention is to provide a new manufacturing method associated with reduced pollution of the environment due to reduced content of the binder component.
Another object of the invention is to provide a new wooden composite tile having improved decorative quality.
In accordance with the invention the above objects and advantages can be achieved by virtue of the following combination of its essential features referring to different groups of its embodiments.
The first group of embodiments refers to a method of manufacturing of a wooden composite tile from a wooden off-cut component, a binder component and a filler component, the said method comprising the following steps:
a) providing a wood off-cut component in the form of plurality of crosscut slices, said slices being pre-cut from the wastes of wood processing industry, said slices having substantially circled shape defined by a height h and by a first and a second parallel opposite surfaces,
b) placing said slices within a die, said die having its flat bottom surrounded by the side walls, the configuration of the die mating the configuration of the ready tile, said slices being arranged on the bottom of the die so as their first surfaces face the flat bottom and define the face side of the ready tile and their opposite second surfaces protrude from the bottom,
c) applying an adhesive to the second surfaces of said slices,
d) filling the die by a mixture of the binder component with the filler component,
e) hot pressing the content of the die so as to achieve the required thickness H of the ready tile, wherein the time T required therefor is defined by the relationship T=0.5 kH, where T is the pressing time in min, k is an empirical coefficient taking into consideration the height h of the slices and their thermal conductivity and H is required thickness of the ready tile in mm,
f) ejecting the ready tile from the die,
g) maintaining the ready tile at room temperature for not more than 72 hours,
h) grinding the face side of the ready tile and bringing its overall dimensions to the required tolerances.
In accordance with one of the embodiments said cross-cut slices are pre-cut from the wood wastes having substantially rectilinear shape with the length 0.3-1.5 m and diameter 40-150 mm.
As per other embodiment said slices are pre-cut so as to have their height h not less than 0.5H, where H is the required thickness of the ready tile and said slices are selected so as to have their respective maximum, intermediate and minimum diameters D 1 , D 2 and D 3 defined by the following relationships D 2 =0.4 D 1 and D 3 =0.1 D 1 .
In the alternative embodiment said pre-cut slices are dried before they are placed in the die.
According to the further embodiment said adhesive is identical with the binder component.
As per further embodiment after the applying the adhesive the slices are maintained at room temperature for at least 20 minutes before the filling of the die with the mixture of the binder component and the filler component.
In yet another embodiment said slices are pre-cut up to thickness h=8 mm.
According to the other embodiment said ready tile is a decorative panel with the thickness H=18 mm and the hot pressing is effective by applying of pressure of at least 1.5 MPa and temperature of 150-200° C.
In accordance with the further embodiment said ready tile is a decorative furniture board and said slices are arranged across the bottom of the die so as to provide a pattern.
As per another embodiment said slices comprise semicircles and sectors.
As per still another the slices which are configured as sectors are placed in the corners of the die, the slices configured as semicircles are placed along the walls and the slices configured as circles are placed across the reminder of the bottom.
In accordance with the further embodiment said the slices which are configured as circles have substantially similar diameter.
The second group of embodiments refer to the ready tile made of wood wastes.
According to one of the embodiments referring to this group the article is a wooden tile configured as a flat body defined by a face side, a parallel thereto rear side and by lateral walls, the interior of said body comprising
a) a wood off-cut component in the form of plurality of crosscut slices, said slices being pre-cut from the wastes of wood processing industry, said slices having substantially circled shape defined by a height h and by a first and a second parallel opposite surfaces, the first surfaces of said slices form the face side of the tile, said slices are selected to have their respective maximum, intermediate and minimum diameters D 1 , D 2 and D 3 which are defined by the following relationships D 2 =0.4-0.5 D 1 and D 3 =0.1-0.5 D 1
b) a binder component and
c) a filler component,
while the filler and the binder components occupy at least part of the empty spaces between the adjacent slices and form the rear side of the ready tile.
As per further embodiment of the tile it is defined by the thickness H, wherein the height h of the slices is at least half of the thickness H.
In yet another the face side of the tile is formed by the slices having dissimilar diameters, wherein at least part of the empty spaces between the adjacent slices is filled by the slices of lesser diameter and by a mixture of the binder component with the filler component.
As per further embodiment said slices form a pattern.
In the further embodiment said tile is a decorative furniture board configured as a rectangular body and said sector shaped slices are located in the corners thereof, the semicircle shaped slices are located along the walls thereof and the circle shaped slices occupy the reminder thereof.
The binder component of the tile can be formaldehyde containing resin and the filler component of the tile can be mixture of saw dust, wooden particles and pieces of thinly sliced wood.
For a better understanding of the present invention as well of its benefits and advantages, reference now will be made to the following description of its various above mentioned embodiments taken in combination with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a tree branch used as wood cut-off raw material.
FIG. 2 is a section of the branch suitable for cutting into crosscut slices.
FIGS. 3 a, b, c present a crosscut wooden slice pre-cut from the rectilinear section shown in FIG. 2 .
FIG. 4 shows different configurations of crosscut slices pre-cut from the cut-off raw material.
FIG. 5 shows how plurality of individual slices presented in FIG. 4 are placed on a flat support to form the tile's face side.
FIG. 6 shows part of a molding die filled with crosscut slices having various diameters.
FIG. 7 is a fragment of a hot-pressed tile showing its face side and rear side.
FIG. 8 shows a fragment of a ready tile with its face formed from wood slices arranged in a pattern.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 it is shown an example of a lumber cut-off waste which can be used for implementation the present invention. This raw material is especially suitable for manufacturing of such articles like splint slabs or similar tiles. The face side of these tiles can be formed by wood crosscut elements which are pre-cut from branches, trunks or other lumber wastes of commercial wood of first, second, and sometimes third rate quality, fruit wood, decorative wood, felled trees or from substandard lumbering cutoff wastes.
The raw material preparation for forming the face layer of a wooden tile includes the following stages:
cleaning the selected branch form the branches of higher order and from the crust,
seeking for relatively rectilinear branches and their sawing along cross-sections a, b, c, d, e, f so as to obtain rectilinear crosscut sections of rectilinear shape as shown in FIG. 2,
preliminary drying of rectilinear sections in open piles to moisture 22-28%,
cutting of pre-dried sections into crosscut defined by thickness h, by a first and a second flat opposite surfaces 1 , 2 and shaped as shown in FIGS. 3 a, b, c,
final drying of pre-cut slices to moisture 8-12%,
sorting out pre-cut slices;
preparation of non-circled slices required for manufacturing the tile with patterned face side (if required),
sorting out of pre-cut slices according to their diameter.
It is advantageous to use rectilinear sections with length of at least 0.3 mm, being preferably 0.3-1.5 m and diameter 40-150 mm for preparation of slices. The thickness h of slices is chosen to satisfy the following equation:
h =0.5H+g+e
where:
H—is the required thickness of the ready article,
g—is the depth of grinding which is carried out in he end of the manufacturing process,
e—allowed deflection or waviness of the slice after drying. The allowed waviness should be within 0,9-1,2 mm.
It is advantageous if the final drying of pre-cut slices is carried out in drying chambers in which the slices are arranged in a single row and put on a grid foundation. The distance between the grid rows should be sufficient for obtaining homogeneous flow of hot air over the first and second slice surface in order to prevent warping (distortion). The drying conditions depend on the particular type of the drying chamber and are selected empirically. The main condition for setting up the drying parameters is bringing down the moisture of slices to 8-12% within the shortest possible time and with minimal rejects due to warping.
The sorting out step includes visual inspection for detecting slices with radial cracks and warped slices. Slices with visible radial cracks or with waviness beyond the allowed value e are cut into pieces so as to obtain smaller slices of non circled shape. With reference to FIG. 4 there are shown various configurations of slices which are obtained from the cut-off raw material. These slices include crosscut circle shaped slices C, D, E having their respective diameters D C , D D , D E , sector shaped slices A, semicircle shaped slices B and small rhomboid shaped and triangle shaped slices F, S.
It will be explained further how one can use the non-circled slices for patterning the face side of an article manufactured from the crosscut off-cut wastes.
In general in order to form the face side of a wooden tile the slices of any shape can be used. At the same time there exist some rules and restrictions dictated on the one hand by the economic effectiveness and from the other hand by the requirement to provide appropriate decorative pattern of the ready article. From this point of view it has been revealed that it is advantageous if the circled slices are divided into three groups with diameters satisfying the following relationship. The ratio between the diameters D C , D D of slices C and D should be D D =0.44D C (mm) and the ratio between the diameters D C , D E of slices C and E should be D E =0.11D C (mm). In practice diameter D C is 40-150 mm depending on the particular cutoff row material.
Now with reference to the following non limiting examples the process of manufacturing according to the present invention will be described in more details.
EXAMPLE 1
The manufacturing process refers to manufacturing of a decorative wall panel. The process comprises the following sequence of steps:
preparation of the face side of the panel for subsequent molding thereof,
molding of the panel,
calibration of the panel size according to the acceptable standard,
polishing of the face side,
coating the face side of the panel by a lacquer.
With reference to FIGS. 5, 6 it is shown how crosscut slices with various configuration are placed on a flat bottom 3 of a die 4 having configuration of the ready panel. The slices are arranged as a layer to fill the content of the die defined by its bottom 3 and by side walls (only walls 5 , 5 ′ are shown). It can be seen that the empty spaces between the adjacent circled slices A, B, C are filled either by circled slices D, E of smaller diameter or by non-circled slices F, S. By virtue of this provision it is possible to fit the slices tightly within the die. Those surfaces of the slices which face the bottom of the die will form the face side of the ready panel, while the opposite surfaces which protrude from the bottom will form part of the rear side of the panel. It is advantageous the die's bottom and the side walls are coated with an anti adhesive layer 6 for example made of coarse paper. The slices are arranged within the die in the following sequence: first the circled slices A, B, C having approximately the same diameter are placed and then the free spaces between the slices and the reminder of the bottom surface is filled with the circled slices D and E having smaller diameter. It might be advantageous to use vibration for more efficient arranging the slices within the die.
After the slices are placed in the die their protruding surfaces are coated by an adhesive. This procedure should be carried out 20-60 min prior the beginning of the molding step and during this period the die with the coated slices is stored at room temperature. The purpose of this measure is to provide conditions for more homogeneous distribution of the adhesive across the slice surface and for penetration between the slices. In practice the appropriate adhesive can be suitable formaldehyde based resin, but it is most convenient to use as an adhesive the same binder component which will be used in the further molding step. The adhesive can be applied by gluing rollers or manually by a brush. The adhesive consumption per 1m 2 of the slice surface can be 100-150 g. Care should be taken not to leave the dried slices with moisture 8-12% for a long time in the open room with moisture 60-65%.
Now the die is filled by a mixture of the binder component with the filler component. This mixture is placed over the slices so as to penetrate between them during the molding step and also to form the rear side of the panel. The appropriate binder component is a formaldehyde based resin, which can be modified by an activating additive, e.g. an carbamido-containing additive. The appropriate filler component consists of saw dust, particulate wood and pieces of thinly sliced wood (wooden chips). It is important that the moisture of the sawdust is within 2-6%. The preferred particle size of particulate wood is 5-8 mm. In practice the mixture may consist of 75-76 vol. % of the filler component and 24-26 vol % of the binder. The amount of the mixture placed on the protruding surfaces of the slices should be sufficient for molding the article having required overall dimensions and density. Since the die's interior is already occupied by the slices the required amount of the mixture will be less than it might be required for manufacturing of the article without slices. Empirically it is established that the volume of the mixture required for the manufacturing process of the present invention is by 55-60% less than in manufacturing of wooden articles without crosscut slices. It can be readily appreciated that the required amount of the binder component is reduced accordingly.
The molding step comprises a hot pressing procedure. The fragment of the panel after it is hot pressed is shown in FIG. 7 . It can be seen that the panel is configured as a flat body defined by its decorative face side 7 and by its opposite rear side 8 . The major part of the face side is formed from plurality of crosscut slices and by the filler component which has penetrated between the slices. By virtue of this provision the face side features natural and contiguous structure of the crosscut wood and thus the ready tile is esthetically more attractive.
The rear side of the tile consists of the mixture of the binder with the filler. The total height of the panel is H.
The hot pressing conditions are set up empirically taking into account the change of volume of the content of the die which should bring to the required height H. It has been empirically revealed that the best results can be obtained in the time of the hot pressing procedure satisfy the following equation:
T=0.5 kH min/mm (2)
where
T—is hot pressing time, min
H—required thickness of the article, mm
k—is empirical coefficient depending on the h/H ratio and on thermal conductivity of the wood. In practice k can vary from 0.85 to 0.96 and for example if h/H=0.45 k=0.9.
The hot pressing step is carried out at a temperature and under pressure which enable manufacturing of the ready article with required height and density. In practice the density varies between 400-1000 kg/m 3 , the hot pressing temperature varies between 150-200° C. and the pressure varies between 1.5-2.2 MPa.
In particular the hot pressing conditions for manufacturing of plates with density 650-850 kg/m 3 and thickness H=18 mm are temperature 170-180° C., pressure 2.2 MPa, hot pressing time T=8.1 min. The above conditions are suitable for utilization of crosscut slices with height h=8 mm prepared from wastes of spruce, pine or other light commercial wood.
It can be readily appreciated that for effecting the above described steps one can use automatic equipment instead of time and labor consuming manual operations associated with the known in the art methods which also employ crosscut slices.
After completing the hot pressing step the articles are stored at room temperature in piles for not more than 72 hours and then are cut to required external dimensions. The face side of the ready articles is ground so as to improve the surface roughness.
In order to prevent the face side from the absorption of moisture it can be coated by a lacquer. The appropriate lacquer should have good adhesion to wood and be insensitive to temperature and moisture changes. Some examples of appropriate lacquers comprise lacquers based on saturated polyester resins, alkyd-styrol resins, etc.
EXAMPLE 2
In manufacture of articles for use as furniture decorative boards the article pattern is considerably dependent on the face side structure and becomes an essential feature. One of the characteristics of a furniture board is the presence of elements that impart the completeness to the appearance of the ready article. A frieze formed by special arrangement of slices along the plate lateral sides is one of such elements. The frieze is used for matching the pattern of adjacent boards and it imparts the completeness to the furniture decorated by such boards and by thus improves the decorative qualities. Despite the use of a frieze in manufacture of decorative wall panels is not an ultimate condition, nevertheless it might be desirable in manufacturing of furniture boards. With reference to FIGS. 4, 8 it will be explained now how the furniture decorative board with patterned face side can be manufactured in accordance with the present invention. The crosscut slices are prepared as described above.
The die having configuration mating the configuration of the furniture board is filled with the slices in the following sequence:
the corners are filled with semicircle shaped slices A.
the lateral sides are formed by placing the sector shaped slices B along the die walls
the remainder of the interior is filled with the circled slices C having the largest diameter D C
circled slices D of lesser diameter D D are fit within the gaps between the slices C and circled slices E of diameter D E are placed around the slices D if there is enough room
when the wood cutoffs with round cross-section are utilized to form the face side of the board (cutoffs of veneer sheets, plywood, etc.) then the slices having rhomboid and triangular shapes F, S can be used to fill the empty space between the other slices.
The rest of manufacturing steps is similar to what is described in example 1, however in addition to the above it comprises also lamination of the rear side of the article and gluing protective coating on tis lateral sides.
It will be appreciated that the present invention is not limited to the above-described embodiments and that changes and modifications can be made by one ordinarily skilled in the art without deviation from the scope of the invention as will be defined below in the appended claims.
The features disclosed in the foregoing description, and/or in the following claims, and/or in the accompanying examples, and/or in the accompanying drawing may, both separately and in any combination thereof, be material for realizing the present invention in diverse forms thereof.
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A method of manufacturing tiles from waste wood uses round crosscut wood slices, a binder, and a filler. The slices, all generally of a thickness, are placed on the flat bottom of a die within side walls. Adhesive is applied to the slices and the die is filled with a mixture of the binder and the filler. The die contents are hot pressed to achieve the required tile thickness. The tile is ejected from the die and then maintained at room temperature for not more than 72 hours. The face side of the tile is ground and the dimensions of the tile are brought within the required tolerances.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of provisional patent No. 60/208,968, filed on Jun. 2, 2000.
TECHNICAL FIELD
This invention relates generally to the steering of the various sections of mobile articulated machines, and particularly to the steering of a section that is steered as a robot by a non-human control system. The preferred embodiments of the invention demonstrate a way of applying the principles of the invention to over-the-road tractor-trailer combinations. A driver controls the steering of a lead tractor, which carries the first trailer.
BACKGROUND OF THE INVENTION
Over-the-road transport companies find it difficult at times to compete with other freight haulers due to labor costs. Labor costs could be decreased if each tractor-trailer rig could carry more weight, but weight limits have been placed on roads and bridges for structural reasons. Multi-trailer arrangements have been seen as a possible solution to this problem because they spread the load over a longer stretch of pavement and reduce the columnar loading on bridges. These arrangements generally involve long combination vehicles, a semi-trailer carried by the tractor with one or more full trailers composed of semi-trailers carried by dollies, called “doubles” and “triples”.
These long combination vehicles face the two interconnected problems of instability and lack of maneuverability, with each following dolly (with trailer attached) becoming less stable at speed and, also, each following dolly “cutting the corner” more than the vehicle segment in front of it during cornering. The standard Type A dolly has achieved some degree of success over the years by striking a point between the two problems. It hitches to the towing vehicle or first trailer using a single point hitch. The standard Type A dolly provides steering for the trailer it is carrying by allowing the entire dolly to steer relative to its semi-trailer about the fifth wheel vertical axis on the dolly as well as relative to the towing trailer about the single point hitch vertical axis. The dolly tires however, do not steer relative to the dolly frame.
Commercial vehicles of either truck and full trailer or multi-trailer configurations which employ the standard Type A dollies generally possess undesirable characteristics such as limited maneuverability and instabilities caused by rearward amplification. Rearward amplification, sometimes described as a crack-the-whip phenomenon, implies that in rapid evasive maneuvers such as emergency lane changes, the rearward elements of the vehicle train such as the dolly and the trailer carried by the dolly experience motions which are substantially amplified compared to the motions of the towing tractor and first trailer. Rearward amplification is known to be the basic cause of many accidents in which roll over of the last trailer or second trailer occurs while the remaining elements of the vehicle remain unscathed.
A second general class of dollies known as Type B dollies represents an improvement over standard Type A dollies. Type B dollies are generally characterized by a double tow bar arrangement, which eliminates steering of the dolly with respect to the towing vehicle, most commonly the first trailer. The Type B dollies have been effective to a degree against some of the instability problems and are slightly more maneuverable than the standard Type A dollies. However, they cause other problems such as introducing other types of instabilities, causing stresses on the rear of the forward trailer, and increasing unloading delays due to difficulty in accessing the back of the forward trailer for some configurations.
Steerable Type A dollies address the stability problems, but are even less maneuverable than Standard Type A dollies.
The long dolly of provisional patent No. 60/204,513 addressed these problems by switching between a stability and a cornering or maneuverability mode. The application of drive power to the dolly axles, provisional patent Ser. No. 09/776,211 did not change the steering but did allow the long dolly (with its trailer attached) to swing wider around a corner in the path dictated by steering modes that demanded a closer emulation of the behavior of the tractor.
Although an improvement, these modes of steering for the long dollies, stability and cornering, did not truly track the path of the tractor, but only traced a path that represented a typical expected path for a given maneuver. Clearly a mode of steering is needed for these long combination vehicles that would ensure that the following vehicle tracked the path of the forward vehicle as closely as possible, especially during critical cornering maneuvers in tight places.
A similar problem exists in narrow city streets where equipment must be delivered to an emergency site such as a fire, or where the delivery of other materials is required. A sectioned vehicle in which each short section followed the path of the first section would be better able to negotiate such streets than a single long vehicle. Similarly, in a convoy of RV's traveling together, each vehicle requires a driver. If a mode of path tracking steering existed which would assure that successive vehicles followed the same path as the lead vehicle, a single driver might steer a convoy of several vehicles.
SUMMARY OF THE INVENTION
The present invention advances the concept of a robotic vehicle that is capable of tracking the path of a lead vehicle. At this point the device can no longer be considered a mere dolly but must more properly be called a robotic vehicle or robotic tractor, because it is fully capable of steering itself in response to input and of propelling itself during cornering. It is also capable of selecting other desired steering modes, including, for example, a mode in which the stability is enhanced at a slight expense to its tracking capability.
The details of this robotic tractor include mathematical equations and algorithms, electronic hardware, and a mechanical system.
OBJECTIVES OF THE INVENTION
It is an objective of this invention to advance the concept of a robotic vehicle that is capable of tracking the path of a lead vehicle, and that is fully capable of steering itself in response to input, of propelling itself during cornering, and of selecting other desired steering modes, including, for example, a mode in which the stability is enhanced at a slight expense to its tracking capability.
It is an objective of this invention to present a mathematical model that would allow a multiplicity of path-tracking and non-path-tracking steering algorithms to be combined in a coherent manner using a variety of weighting factors, and to point toward even more complex control algorithms.
It is an objective of this invention to provide a plurality of mathematical algorithms based on physical principles and on the geometry of the vehicle configurations, each of which is compatible with the above system for combining algorithms, for steering a robotic vehicle to track the path of a lead vehicle.
It is an objective of this invention to present an electronic control system, preferably including hardware such as sensors, actuators, and other I/O devices, RAM, ROM, and other data storage devices, and digital processors, that is capable of acquiring data from these sensors, using that data as input to algorithms to generate control signals, and using these control signals to activate steering and other control components to enable a robotic vehicle to track the path of a lead vehicle.
It is an objective of this invention to present a mechanical system that is capable of being controlled by the actuators to track the path of the lead vehicle, thereby eliminating the need for a second operator for the second vehicle.
ADVANTAGES OF THE INVENTION
The first advantage of this invention is the increase in maneuverability for shorter sectioned delivery or emergency vehicles in places such as narrow city streets. The long wheelbases of standard trucks and tractor-trailer combinations cause them to “cut the corner” during turns. In narrow city streets such as those found in many European cities, this behavior could be disastrous. A vehicle composed of a number of shorter sections that were steered so that each section tracked the first section could solve some of the problems in these types of situations.
Another advantage of this invention is the savings in labor costs in applications such as over-the-road freight transport. The length of the robotic tractor spreads the load and permits more weight to be carried by a single long combination vehicle driven by a single driver. A robotic tractor “double” eliminates one driver, and a robotic tractor “triple” eliminates two drivers. At the same time, because of the ability of the robotic tractor(s) to track the path of the lead tractor while carrying its own trailer, the loss of maneuverability is minimal. Because of the length and because of the capability for using a more stable mode at higher speeds, there is also no appreciable loss of stability as compared to a single tractor-trailer rig.
Another advantage of this invention is that it requires minimal supervision from the driver. The controller is programmed to steer using input from its sensors (such as speed of travel or quickness of a turn), and by taking clues from the normal control activities of the driver. To set up the long combination vehicle, the driver has only to adjust the length of the tongue and input the length of the tractor and the trailers.
Another advantage of this invention is that the robotic tractor embodiment can carry standard semi-trailers with only very minor modifications. Standard tractors could also be used as lead tractors with only slightly more substantial modifications, such as the addition of the appropriate sensors.
This invention offers the stability of the steerable Type A dollies but with better cornering capabilities than the Type B dolly. It also takes advantage of the reduction in cost and the rapid growth in the capabilities of electronic computing hardware.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of a tractor-trailer long combination rig
FIG. 2 is a diagrammatic perspective plan view of a robotic tractor according to one embodiment of the articulated machine of the present invention
FIG. 3 is a diagrammatic back plan view of a robotic tractor according to one embodiment of the articulated machine of the present invention
FIG. 4 is a diagrammatic top view taken along the lines 4 — 4 of FIG. 3 of a robotic tractor according to one embodiment of the articulated machine of the present invention
FIG. 5 is a diagrammatic top view of a robotic tractor according to one embodiment of the articulated machine of the present invention
FIG. 6 is a diagrammatic close up of the rear section of atop view of a robotic tractor according to one embodiment of the articulated machine of the present invention
FIG. 7 is a diagrammatic view of a tractor partial circular track with associated sensors
FIG. 8 is a diagrammatic back view of a second embodiment of the present invention
FIG. 9 is a diagrammatic top view of a second embodiment of the present invention
FIG. 10 is a diagrammatic top view detail of a stinger
FIG. 11 is a diagrammatic end view detail of a transverse axle and axle hanger assembly
FIG. 12 is a diagrammatic back view detail of a transverse axle hanger assembly and traction kinking air motor assembly
FIG. 13 is a diagrammatic view of a double-axle wagon according to one embodiment of the articulated machine of the present invention
FIG. 14 is a diagrammatic representation of a lead tractor and trailer making a turn
FIG. 15 is a diagrammatic representation of a robotic tractor and trailer making a turn
DETAILED DESCRIPTION
A system for steering a trailing section of an articulated machine is shown as embodied in a tractor-trailer combination rig, but other articulated machines are considered equivalents and within the scope of the invention. In FIG. 1 a tractor-trailer combination rig having first, second, third and fourth pivotally connected articulated machine sections is shown as a tractor 30 , forward trailer 40 , robotic tractor 50 , and rear trailer 80 . Information is obtained from the various sensors and input to a controller 49 , which can be a processor or computer. The controller 49 uses algorithms to extract necessary information about orientation, speed, etc. from the input data, and then determines the necessary action to obtain the desired steering result.
Three steering algorithms are described. The relative angle steering mode and the rate of orientation change steering mode are methods of path tracking steering. The third method, variable ratio with oversteer from provisional patent No. 60/204,513 is an independent mode. The traction kinking system is included from provisional patent Ser. No. 09/776,211. Full redundancy for all the electronic components would be desirable to minimize the consequences of failures, but for simplicity such redundancy is not included in this description of the invention. Energy must be supplied to power the robotic tractor 50 steering system and traction kinking system. Various means, including air, hydraulic, or electric power or a combustion engine would suffice. In this embodiment compressed air and pressurized hydraulic fluids are utilized as energy sources.
Three embodiments are described. A simpler embodiment is shown in FIGS. 1 through 7 as a robotic tractor with a single steering mode, the relative angle path-tracking mode. The second, more complex, embodiment utilizes both the relative angle path tracking mode and the rate of orientation change path tracking mode as well as the independent ratio with oversteer steering mode, shown in 1 , 7 , 8 , 9 , 11 , 12 , and 13 . This embodiment also uses traction kinking to assist in swinging wide around corners. The third embodiment, a double axle wagon, towed behind a pickup truck or other small vehicle, is shown in FIG. 14 .
FIG. 1 illustrates a typical application of a robotic tractor with its attached trailer towed behind a tractor-trailer combination rig, as in the first and second embodiments. A lead tractor 30 of a tractor-trailer combination has a first trailer 40 coupled thereto via a pair of fifth wheels 36 L, R. Behind this first trailer 40 is attached the steerable machine section that we refer to as the robotic tractor 50 . A second trailer 80 is mounted on the robotic tractor 50 by another pair of fifth wheels 67 L, R.
Two sensors are mounted on the tractor 30 to determine reference steering information about the path the lead tractor 30 has traveled in the first embodiment. This reference steering information for the path tracking steering modes comes from a sensor θ R0 42 (FIG. 7) mounted on the tractor partial circular track 250 between the tractor 30 and the front trailer 40 to determine the angle θ R0 between the tractor 30 and the front trailer 40 , and linear motion sensor ΔT 34 (FIG. 1) mounted on the tractor 30 in order to determine the distance traveled by the tractor 30 . The rotation of the tractor drive shaft is utilized to obtain this measurement, but other methods could be used to obtain it. In the second embodiment a third sensor, θ F 31 (FIG. 1 ), is located to sense the angle θ F between the tractor 30 centerline and the centerline of the front wheels of the tractor 30 .
FIRST EMBODIMENT
The first embodiment of the invention has a long rigid main robotic tractor frame or tongue 55 , which is the central rigid structural member. The front of the tongue 55 is attached at hitch latch 108 to the forward trailer 40 .
At the rear of the robotic tractor there are three sections which each pivot in relation to each other, with a single vertical pivot point, best seen in FIG. 3 . The uppermost section is a trailer mounting bar 66 with its two attached fifth wheels 67 L, R. The middle section is the robotic tractor frame or tongue 55 . The lowest section is a steering axle assembly 60 with attached running wheels 70 L, R.
In the uppermost section, the trailer mounting bar 66 is free to swivel around the trailer mounting bar central pivot 65 (FIG. 3 ). This trailer mounting bar 66 pivots above the tongue 55 and around the same line as the steering axle assembly central pivot 58 . Mounted on this trailer mounting bar 66 are the two fifth wheel latches 67 L, R by which the rear trailer 80 will be coupled to the robotic tractor in this embodiment, instead of the single fifth wheel coupling that is usually used. The trailer mounting bar 66 and the rear trailer 80 (FIG. 1) are allowed to pivot above the main robotic tractor frame 55 as the rear trailer 80 (FIG. 1) swings from side to side with respect to the robotic tractor. This movement is accurately measured and communicated to the processor 49 by the movement of the optical rotation encoder θ R1 81 mounted adjacent to an upper partial-circular track 140 .
The upper partial-circular track 140 attaches at an attachment assembly 141 at its endpoints to the trailer mounting bar 66 and pivots with it during turns. Bearing plates provide stability for this pivot 65 . This upper partial-circular track 140 is mounted sufficiently above a rear partial-circular track 75 to easily clear it during operation and to allow unobstructed operation of both rotational systems.
The middle pivotal section of the robotic tractor 50 is the frame or tongue 55 (FIG. 3 ). Both the steering axle assembly 60 below the tongue 55 , and the trailer mounting bar 66 above the tongue 55 are mounted on pivots extending downward and upward respectively from the tongue 55 , and pivot with respect to the tongue 55 . The tongue 55 is attached to the forward trailer 40 by a of some type. A front pivot orientation sensor θ D1 44 (FIGS. 4 , 5 ) is mounted on the front partial circular track 100 to measure the angle θ D1 between the robotic tractor tongue 55 and the front trailer 40 centerline. The front partial circular track 100 is attached as shown in FIGS. 4 and 5 by ball type hitch latches 106 L, R that are attached to the front of the partial circular track 100 , but other methods could be used.
The axle assembly central pivot 58 (FIG. 3) is mounted on the bottom of the robotic tractor tongue, and a corresponding trailer mounting bar central pivot support 65 above the tongue 55 and in line vertically with the axle assembly pivot support 58 is the pivoting attachment for the trailer mounting bar 66 . The axle assembly 58 pivots in relation to the robotic tractor tongue 55 in response to torque applied by a hydraulic steering motor 68 via a chain 69 (FIGS. 4, 6 ). The angle between the robotic tractor tongue 55 and the axle assembly 60 is read by a sensor θ S1 53 (FIG. 4 ). The sensor θ S1 53 obtains the angle between the robotic tractor tongue 55 and the axle assembly central pivot support 58 as shown in FIG. 4 by measuring the rotation of the lower partial circular track 75 .
The tongue 55 of the robotic tractor will be longer than the typical dolly tongue 55 , because if it is to correct for the deviation the trailer ahead of it caused it will need to be roughly on par with the length of the front trailer 40 . The degree of similarity in length will depend on various factors; the longer the robotic tractor tongue 55 , the easier it will be to correct the course deviation, but the more awkward the assembly will be. A short tongue would allow a degree of course correction, and how short the tongue can be made will depend on how accurately the robotic tractor 50 is desired to follow the path of the main trailer 40 . The long tongue provides an advantage in that the length of the tongue would allow the vehicle to carry more weight, because the weight characteristics would be more like two tractor-trailer rigs in close convoy, rather than one tractor towing two trailers. By spreading the load over a longer span, this extra length has the highly desirable benefits of reducing the stresses on the pavements and reducing the columnar loading on the bridges of our highway systems, thus allowing a heavier load to be pulled.
The lower pivotal section is a steering axle assembly 60 with attached running wheels 70 L, R. The steering axle assembly 60 is mounted on the vertical axle central pivot 58 (FIG. 3) which extends below the main robotic tractor frame or tongue 55 and is able to swivel around on this axle central pivot 58 (FIG. 3 ). Bearing plates provide stability for this axle central pivot 58 .
The steering axle assembly 60 and two spaced pairs of running wheels 70 R and 70 L, which it carries, are mounted beneath the main robotic tractor frame 55 along with any conventional suspension system components that may be needed. In this embodiment the suspension system is omitted for clarity of illustration since it is composed of standard assemblies. A double-axle steering section that turns as a unit, two independent steering axles, or any other suitable configuration would be possible, but, for simplicity, this embodiment of the invention is shown with a single axle.
The sensor assemblies and the hydraulic motor assemblies, which enable the controlling processor to steer the steering axle assembly 60 , are mounted generally above the main robotic tractor frame 55 and in front of the transverse axle 72 . These assemblies include the upper partial circular track 140 , a lower rear partial-circular track 75 , one hydraulic motor 68 , two optical rotation encoders θ R1 43 and θ S1 53 or some such sensors, and several additional components. Mounted on the axle drive shaft 202 (FIG. 12) of the robotic tractor 50 , sensors ΔS 1 — LEFT 52 L and ΔS 1 — RIGHT 52 R measure the rotation of the axle of the robotic tractor 50 in order to determine the distance traveled by the robotic tractor 50 . The average of the sensors ΔS 1 — LEFT 52 L and ΔS 1 — RIGHT 52 R is ΔS 1 . Mounted on the steering axle 72 are two air motors 170 L, R, (FIG. 12) which provide power to the wheels 70 L, R of the robotic tractor as needed.
The steering axle assembly 60 (FIG. 3) has an attachment at the top via a track attachment assembly 73 L and 73 R near the extremities of a rear partial-circular track 75 . The partial-circular track 75 is somewhat longer than a semicircle to allow for turns of greater than 90 degrees. The attachment assemblies 73 L and 73 R are designed solidly, but they attach behind the steering axle assembly 60 so that the space directly above the steering axle assembly 60 and forward is empty. This allows above 180 degrees of rotation of the steering axle assembly 60 about the transverse axle central pivot 58 (FIG. 3) in response to the torque applied by the rear partial-circular track 75 .
The bottom of the rear partial-circular track 75 is in the same plane with the top of the main robotic tractor frame 55 . The front of the rear partial-circular track 75 contains a channel with a heavy roller chain 216 . The two ends of the heavy roller chain 216 are attached at the extreme rear points of the rear partial-circular track 75 on each side. At the point where the heavy roller chain 216 passes over the main robotic tractor frame 55 , the heavy roller chain 216 forms a loop forward around a heavy main sprocket 77 , consisting of two coaxial sprockets. Below the heavy roller chain on the main sprocket 77 is a roller chain 69 , which connects the main sprocket with the power output sprocket 76 from the hydraulic steering motor assembly 68 , providing the torque for steering the robotic tractor.
In a separate channel of the rear partial-circular track 75 , just below the channel for the roller chain 216 , a flexible steering cable (inside track 75 , not shown) resides. This steering cable is also attached at the rearmost part of the rear partial-circular track 75 on each side and is pulled tight by a short heavy spring on one of the attachment points. At a point slightly to the side of where this steering cable passes over the main robotic tractor frame 55 , it forms a twisted loop around a flat-bottomed pulley on a shaft rotating around a vertical axis located directly above an optical encoder θ S 53 . As it turns, this shaft rotates the input shaft of this optical rotation encoder θ S 53 mounted on the main robotic tractor frame 55 . This optical rotation encoder θ S 53 provides information to the processor 49 about the orientation of the transverse axle 72 and of the running wheels 70 L and 70 R of the robotic tractor with respect to the main robotic tractor frame/tongue 55 .
Two raised bumps just to each side of the center point on the top of the rear partial-circular track 75 will assist the processor 49 in keeping track of the axle orientation. These raised bumps will activate switches 236 L, R on rollers as they pass underneath the rollers. When both switches 236 L, R are simultaneously activated, the processor 49 will set the orientation of the track 75 to zero degrees.
A forward partial-circular track 100 attaches near its endpoints to the hitching points 106 L, R on the forward trailer 40 and pivots with the forward trailer 40 during turns. A narrow channel on the back of the forward partial-circular track 100 contains a flexible steering cable (inside track 100 , not shown). This steering cable is attached at the front most part of the forward partial-circular track 100 on each side and is pulled tight by a short heavy spring on one of the attachment points. At the center of the tongue, where this steering cable pass over the main robotic tractor frame 55 , it forms a twisted loop around a flat-bottomed pulley on a shaft rotating around a vertical axis. As it turns, this shaft rotates the input shaft of an optical rotation encoder θ D1 44 mounted on the robotic tractor tongue 55 . The pulses from this optical rotation encoder θ D1 44 are transferred via pulse counting circuits to the microprocessor or computer 49 , providing information about the orientation of the forward trailer with respect to the centerline of the main robotic tractor fame 55 .
Two raised bumps just to each side of the center point on the top of the forward partial-circular track 100 will assist the processor 49 in keeping track of the track 100 orientation. These raised bumps will activate switches 854 L, R on rollers as they pass underneath the rollers. When both switches 854 L, R are simultaneously activated, the processor 49 will set the orientation of the track 100 to zero degrees.
The forward partial-circular track 100 is attached to the forward trailer 40 at its extremities via some sort of hitching device that allows some amount of pivoting around horizontal axes while preventing vertical or horizontal movement at the point of hitching to provide support and pulling force. In this embodiment, we will use standard ball hitch type latches 106 L and 106 R to represent the hitch arrangements for the partial-circular track 100 . The heavy central member of the robotic tractor frame 55 attaches to a larger hitching point using a similar, but larger, hitching device that will be represented by hitch latch 108 which will allow pivoting around a vertical axis and some pivoting around horizontal axes while preventing vertical or horizontal movement at the point of hitching. The forward trailer 40 (FIG. 1) must be modified to have hitching points compatible with the robotic tractor hitch latches, which in this embodiment we will represent with hitch balls mounted solidly directly to each side of a heavy central hitch ball. The side hitch balls must be mounted slightly higher than the central ball to line up with their respective ball hitch latches 106 L and 106 R. Note that the partial-circular track 100 is not solidly attached to the main robotic tractor frame, but travels across it, in contact with it, during turns.
FIG. 5 is a top view of the robotic tractor showing details of the upper partial-circular track 140 , with FIG. 6 being a close up of the rear section of FIG. 5 . The upper partial-circular track 140 attaches at its endpoints to the trailer mounting bar 66 and pivots with it during turns. This upper partial-circular track 140 is mounted sufficiently above the rear partial-circular track 75 to easily clear it during operation and to allow unobstructed operation of both rotational systems. A narrow channel on the front of the upper partial-circular track 140 contains a flexible steering cable (inside track 140 , not shown). This steering cable (inside track 140 , not shown) is attached at the rearmost part of the upper partial-circular track 140 on each side and is pulled tight by a short heavy spring on one of the attachment points (in channel, not shown). At of the point where this steering cable (inside track 140 , not shown) passes over the main robotic tractor frame 55 , it forms a twisted loop around a flat-bottomed pulley on a shaft rotating around a vertical axis located directly above the optical encoder θ R1 81 . As it turns this shaft rotates the input shaft of an optical rotation encoder θ R1 81 mounted on the main robotic tractor frame 55 . Pulse counting circuits process the pulses from this encoder θ R1 81 and then pass the data on to the microprocessor or computer 49 , providing information about the orientation of the rear trailer 80 with respect to the main robotic tractor frame 55 .
Two raised bumps just to each side of the center point on the top of the upper partial-circular track 140 will assist the processor 49 in keeping track of the track 140 orientation. These raised bumps will activate switches 242 L, R on rollers as they pass underneath the rollers. When both switches 242 L, R are simultaneously activated, the processor 49 will set the orientation of the track to zero degrees.
In this embodiment of the invention, the two fifth wheel latches 67 L, R on the trailer mounting bar 66 provide the means to transfer the torque between the upper partial-circular track 140 and the rear trailer 80 . Unless some means for transferring this torque was provided, the trailer mounting bar 66 would simply rotate around the kingpin of the rear trailer 80 and any measurement of the orientation of the upper partial-circular track 140 would not be representative of the orientation of the rear trailer 80 .
FIG. 7 is a detail of the lead tractor partial-circular track 250 for measuring the orientation of the forward trailer with respect to the lead tractor. This diagram will apply for both the first and the second embodiments of the invention. The tractor partial-circular track 250 attaches near its endpoints to the forward trailer mounting bar 501 above the rear wheels of the tractor 30 and pivots with it during turns. A narrow channel on the front of the tractor partial-circular track 250 contains a flexible steering cable (inside track, not shown). This steering cable (inside track, not shown) is attached at the rearmost part of the tractor partial-circular track 250 on each side and is pulled tight by a short heavy spring on one of the attachment points. Near the point where this steering cable passes over the centerline of the tractor 30 , it forms a twisted loop around a flat-bottomed pulley on a shaft rotating around a vertical axis. As it turns, this shaft rotates the input shaft of an optical rotation encoder θ R0 42 mounted on the frame of the tractor 30 . Pulse counting circuits then process the pulses from the encoder θ R0 42 R, L, providing the microprocessor or computer 49 with information about the orientation of the forward trailer 40 with respect to the centerline of the tractor 30 ).
Two raised bumps just to each side of the center point on the top of the tractor partial-circular track 250 will assist the processor 49 in keeping track of the track orientation. These raised bumps will activate switches 256 L, R on rollers as they pass underneath the rollers. When both switches 256 L, R are simultaneously activated, the processor 49 will set the orientation of the track 250 to zero degrees.
In this embodiment of the invention, the two fifth wheel latches 36 L, R on the forward trailer mounting bar 501 provide the means to transfer the torque between the tractor partial-circular track 250 and the forward trailer 40 (FIG. 1 ). If no method for transferring this torque was provided, the forward trailer mounting bar 501 would simply rotate around the kingpin of the trailer 40 and any measurement of the orientation of the tractor partial-circular track 250 would not be representative of the orientation of the forward trailer 40 (FIG. 1 ). Alternatively, a stinger 500 (FIG. 13 ), or other device, could be used to prevent rotation around the trailer kingpin.
An optical rotation encoder ΔT 34 (on the tractor 30 itself, mounted in a manner that allow it to sense the rotation of the drive shaft of the tractor 30 , provides information via pulse processing circuits to the microprocessor or computer 49 about movement and speed of the tractor 30 . Note that this encoder must be mounted behind any two-speed axle gearbox(es) in order to give a true representation of the rotation of the tractor drive wheels.
PREFERRED SECOND EMBODIMENT OF INVENTION
FIGS. 8 and 9 show a robotic tractor with path tracking steering, variable ratio with oversteer steering, and traction kinking that is a preferred embodiment of the invention. This embodiment differs from the simpler robotic tractor with path tracking of the first embodiment in several ways. The robotic tractor length can be adjusted in this embodiment. The robotic tractor tongue is split into two parts, 55 a and 55 b , and 55 b can be extended or retracted at the joint 144 , with the pin and lock set 146 holding it in place. This embodiment also uses traction kinking to assist in turning corners. This embodiment uses two separate path tracking modes, relative angle path tracking mode and rate of orientation change path tracking mode, instead of only the relative angle path tracking mode used in the first embodiment of the invention. Also, the variable ratio with oversteer steering mode is included in the combination of steering modes to allow the path-tracking modes to be combined with either a more stable version of the variable ratio with oversteer mode or a more maneuverable version of the variable ratio with oversteer mode. The traction kinking will be disabled when the robotic tractor is traveling in a straight line in order to conserve air pressure.
As described in the operations, the reference steering information for the relative angle path tracking mode comes mainly from sensor θ R0 42 (FIG. 7) mounted on the tractor partial circular track 250 (FIG. 5) between the tractor 30 and the front trailer 40 (FIG. 1 ), and sensor ΔT mounted to sense the rotation of the tractor drive shaft. This information is compared to sensors θ R1 , θ S1 and ΔS 1 . The details of the tractor partial circular track can be seen in FIG. 7 .
The steering information for the variable ratio with oversteer robotic mode comes from θ D1 , θ R1 , θ S1 , and ΔS 1 — LEFT 52 L and ΔS 1 — RIGHT 52 R.
The rate of orientation change path tracking mode will use sensor θ F 31 , the angle of the front tractor steered wheels, and sensors θ D1 , θ R1 , θ S1 and ΔS 1 .
Full redundancy is desirable for all the electronic components so that consequences of failures would be minimized, although this is optional to the invention, and not shown, for simplicity.
The rear partial-circular track 75 and the front partial circular track 100 are configured in the same way as in the first embodiment.
This complex embodiment includes a traction kinking system for assistance in cornering. The operation of this system is described in the operations.
The arrangement of the rear partial-circular track 75 and the front partial circular track 100 , along with the associated sensors and switches is essentially identical to the arrangement of the equivalent structures of the first embodiment described above, and will not be repeated at this point.
To allow the main frame 55 to be manually adjusted, there is a joint 144 . At this joint 144 , a smaller main robotic tractor frame 55 b section slides into a larger main robotic tractor frame 55 a section and is secured by some type of mechanism such as a pin and lock set 146 to prevent slippage or movement during operation.
The arrangement of the upper partial-circular track 140 , along with its sensors and switches is essentially identical to the arrangement of the equivalent structures of the simpler embodiment described above, however, in this embodiment of the invention, an articulated stinger assembly 500 is used instead of the second fifth wheel latch 67 L, R on the first embodiment of the invention. This stinger assembly 500 extends backward from the trailer mounting bar 66 to provide the means for transferring the torque between the upper partial-circular track 140 and the rear trailer 80 . A detailed treatment of this stinger 500 will be presented in FIG. 13 . The stinger 500 is used to prevent the rotation of the trailer mounting bar 66 around the kingpin of the trailer, in order to obtain an accurate measurement of the orientation of the rear trailer 80 .
As mentioned above, optical rotation encoders ΔS 1 — LEFT 52 L and ΔS 1 — RIGHT 52 R (FIG. 12) will record the rotation of the drive shaft for each robotic tractor wheel 70 L, R. The software in the microprocessor or computer 49 will use this information in two ways. The average of the distance traveled by the left and right wheels 70 L, R will yield the distance traveled by the robotic tractor in any given time interval. The difference in the distance traveled by the left and right wheels 70 L, R will be scaled to yield a measure of the amount of cornering that the robotic tractor wheels 70 L, R are undergoing. This difference will be used with the ratio with oversteer mode. The details of this operation will be covered in the Operations section.
The primary microprocessor or computer 49 would be in control at any time with the secondary microprocessor or computer continually performing a check on the operation of the primary microprocessor or computer 49 and taking control of the operation if the situation warranted it. Any significant discrepancies could be reported to the driver as a warning. Since each microprocessor or computer 49 has access to all the sensors, errors can be detected and corrective actions taken.
Below the main robotic tractor frame 74 a heavy axle hanger central pivot 58 supports and allows pivoting of the steering axle assembly 60 and of the transverse axle 72 with its associated components. Bearing plates provide stability for this pivot. The traction kinking motors can be seen inside the steering axle assembly
FIG. 11 shows an end view of a detail of the transverse axle 72 inside the axle hanger assembly 75 . Since the input to the kinking system is the sideways force on the robotic tractor axle 72 , we must have some way of measuring this force. In this embodiment of the invention, the transverse axle 72 , together with the air motors for the traction kinking system, is mounted in an axle hanger assembly 75 that allows some movement from side to side in response to a sideways force. This movement is used to activate air regulator switches 183 , 184 (FIG. 12) (or some such device) on each side, which then power the kinking system.
The axle 72 is mounted in the center of an inverted U-shaped channel 172 in the axle hanger assembly 75 . The weight on the axle 72 is supported by a number of vertical arms 174 each of which attach via a pivot 176 at the top to the axle 72 and via a pivot 177 at the bottom to the lower sides of the U-shaped channel 172 . When a sideways force is applied to the axle 72 , the vertical arms 174 swing somewhat to the side in response to the force. At the top and bottom of the channel 172 , roller bearings 180 , 181 in partial-circular races 182 , 183 stabilize the axle 72 against forward and/or backward forces and against twisting movement.
FIG. 12 is a detail of the location of regulator switches or pressure transducers 183 , 184 on the axle hanger assembly 75 . The axle 72 is shown passing through the axle hanger assembly 75 , which rotates on the vertical axle central pivot 58 . The air motors for the traction kinking system, mounted on the axle 72 , are also located inside the axle hanger assembly 75 . The movement of the axle 72 in response to the sideways forces upon it activates a regulator valve or pressure transducer 183 , 184 placed on each side of the axle 72 . Full air pressure from the truck air system is applied to the input side of these switches 183 , 184 . The switches 183 , 184 are designed to send increasing pressure to the traction kinking system as the sideways force increases, in just the opposite manner to the way the force on the brake pedal reduces the pressure to the brakes in an air brake system. During a turn, if the sideways pressure tries to push the robotic tractor to the inside of the turn, air pressure is sent to the air motors in the traction kinking air motor assembly 170 L, R (FIG. 6) to push the robotic tractor wheels 70 L, R (FIG. 8) forward, relieving the pressure. If the sideways pressure tries to push the robotic tractor to the outside of the turn, air pressure is sent to the brake activation system to slow the robotic tractor 72 and eliminate the risk of jackknifing.
The traction kinking air motor assemblies 170 R, L that comprise the power source for the traction kinking drive system are mounted below the transverse axle 72 on each side. Each air motor assembly 170 R, L includes gearing to slow the rotation to the appropriate speed and to increase the torque. The output from each air motor assembly 170 R, L is applied via a gear 200 on a drive shaft 202 that extends out through the center of each wheel 70 R, L. The wheels 70 R, L and the shafts are mounted on bearings in a similar manner to the drive wheels on the back of a truck tractor. No differential is needed, because the two air motors 170 R, L have a common air supply and will apply equal torques to the shafts 200 they are driving. Two optical rotation encoders, one on each drive axle 202 (FIG. 12 ), Δ S1 — Left , Δ S1 — Right 53 L, R record the rotation of the shafts 202 and transfers the information via pulse processing circuits to the microprocessor or computer 49 .
FIG. 12 is a detail of the traction kinking air motor assembly 170 R located on the transverse axle inside the axle hanger assembly. The two similar air motor assemblies 170 L, R convert the air pressure sent by the regulator switches 183 , 184 (FIG. 12) into torque to drive the robotic tractor wheels 70 L, R (FIG. 3 ). Each assembly 170 L, R includes a system of gears to reduce the speed and increase the torque of the air motors 171 L, R. When the air motor 171 R is activated, the shaft 204 R and gear 206 R carrying the output rotation from the air motor assembly 170 R engages a gear 200 R on the end of the axle shaft 202 R that extends out through the center of the wheels 70 R (FIG. 7) on the side of the robotic tractor. This shaft 202 R then causes the wheels 70 R (FIG. 7) to drive forward in a manner similar to the way the drive wheels of the truck tractor operate. Since the two air motor assemblies 170 L, R share a common air pressure source, no differential gears are needed to equalize the torques on the wheels 70 L, R.
FIG. 13 shows a detailed view of the articulated stinger assembly 500 that is attached to the back of the trailer mounting bar 66 . The heavy central bar 546 of the stinger assembly is designed to withstand substantial sideways forces. The locking arms 544 slide freely forward and backward along the heavy central bar 546 , but are prevented by a stop from sliding off the end. Each locking arm 544 consists of three actuating arms 541 , 542 , 543 , the back two of which are parallel, and a contact bar 540 with a heavy solid rubber pad that remains parallel to the heavy central bar 546 during deployment. The entire stinger assembly 500 is mounted to the trailer mounting bar 66 via a spring-supported hinge 548 so that it can be easily positioned during hitching operations.
In this embodiment of the invention, this articulated stinger assembly 500 provides the means to prevent the rotation of the trailer mounting bar 66 around the kingpin of the rear trailer 80 . The stinger locking arms 544 can be slid backward or forward into position between the trailer structural members or between the two legs of the trailer landing gear. The locking arms 544 can then be opened tightly outward against the structural members or the legs of the landing gear to lock the trailer mounting bar 66 rigidly into place with respect to the rear trailer 80 . If the trailer has no solid structures on which to lock the stinger assembly, an adapter can be provided which will allow the stinger to lock to the sides of the trailer itself, with supporting straps going over the top of the trailer.
THIRD EMBODIMENT
FIG. 14 shows a double-axle trailer or wagon that utilizes path tracking and variable ratio with oversteer mode steering with traction kinking. This wagon is designed to be pulled in a “Multiple Wagon Train” configuration behind a three-quarter ton pickup or some such vehicle, so it will be accordingly sized down somewhat from the robotic tractor with path tracking steering, variable ratio with oversteer and traction kinking discussed as the complex embodiment above. As was true for the robotic tractor however, this wagon will require three hitch balls on the towing vehicle. The second wagon in the train will use as input the orientation information from the upper 140 and lower partial circular tracks 75 of the first wagon in the train. The steering system for this wagon is identical to that for the robotic tractor except that control and shifting by the driver and the controlling microprocessor or computer 49 will utilize 12 volt solenoids and/or 12 volt DC motors instead of the air motors used by the robotic tractor. Ratios used for the variable ratio with oversteermode of steering may also be somewhat different for the wagon than for the robotic tractor. The mounting of the partial circular tracks and the sensors will be similar to that for the robotic tractor, but since the back portion of the wagon 554 will be permanently attached to the wagon mounting bar 555 on the front section of the main wagon frame 552 , there will be no need for the two fifth wheels or for the articulated stinger that were present on the robotic tractor.
The traction kinking system must also be modified to operate on 12 volt DC power, and an extra battery may be needed to supply the additional current. Again, the traction kinking system will be disabled when the steered wheels of the wagon are aligned with the centerline of the wagon tongue. The hydraulic steering motor 68 steering wheels will use an electric motor to drive the hydraulic pump.
FIG. 14 is a diagrammatic representation of a lead tractor and trailer making a turn. The angles, lengths, and distances demonstrated in this diagram will be used in the operations section to derive the mathematical equations relating to the rate of orientation change mode of steering.
FIG. 15 is a diagrammatic representation of a robotic tractor and trailer making a turn. The angles, lengths, and distances demonstrated in this diagram will be used in the operations section to derive the mathematical equations relating to the rate of orientation change mode of steering.
Operations
The primary goal of this path tracking steering system is to have the pivot point at the front of the second semi-trailer follow the same path as the pivot point at the front of the first semi-trailer. In the preferred embodiment, two different path tracking modes and one non-path-tracking mode, variable ratio with oversteer mode, are combined in order to steer the robotic tractor. The modes will be combined based on the steering characteristics desired. In most cases, the modes will provide very similar steering output. But in some cases, for example, if the wheels of the vehicle slip sideways, the steering output can differ to a greater degree, depending on the degree of the slippage. The ability to combine a number of different path tracking modes, and even non-path tracking modes such as the non-path-tracking “variable ratio with oversteer” steering mode, will contribute significantly to the reliability of the final product, since errors in one mode are offset by the contributions of other modes.
Full redundancy for all electronic components would be desirable to minimize the consequences of failures, but since ease of understanding is a priority here, redundancy was not included in this embodiment.
A secondary controller is used to check on the operation of the primary controller 49 and could take control if the situation warranted it. Any significant discrepancies between the two controllers could be reported to the driver as a warning.
Output from the Controller to Steer the Robotic Tractor Axles
The robotic tractor is steered by rotating the steering axle assembly about its central pivot 58 (FIG. 3) by applying the steering correction needed for a particular travel interval. This steering correction is generated by the steering algorithms. Each steering algorithm independently generates a parameter that represents this steering correction needed for a particular travel interval. This parameter is named Δ. Each steering algorithm generates a Δ of its own. For example, the rate of orientation mode generates a ΔPath 1 — Rate — of — Orientation . This value Δ indicates the magnitude and direction of the steering angle change that the axle needs to undergo according to the particular steering mode or combination of modes generating the Δ. A positive value of Δ would cause the wheels to be steered more to the right of the robotic tractor centerline, and a negative Δ would cause them to be steered more to the left of the robotic tractor centerline. A larger magnitude of Δ would cause more rapid steering movement.
In this embodiment, a reversible hydraulic motor 68 geared down to a moderate speed will provide the energy for turning the axle when the software detects that movement is required. This hydraulic motor 68 is provided with automatic braking mechanisms that lock the gear train into position at times when no action is required of the hydraulic motor 68 . The hydraulic valves that are activated by the controller 49 to control the flow of the hydraulic fluid to this motor act as a secondary hydraulic braking system. Low air pressure or low hydraulic pressure will cause the motor to move the axle to a straightforward position and then activate the braking mechanisms. The hydraulic motor operates from a reservoir of fluid in a pressure chamber where the hydraulic fluid is separated from a compressed gas by a diaphragm. This hydraulic tank, located in the steering motor assembly, will provide a reservoir of energy for emergency positioning if all power is lost. The fluid in the chambers is continuously replenished during operation by an air motor or electric motor operating a high-pressure hydraulic pump in the steering motor assembly.
The Traction Kinking System
The traction kinking section is used to prevent sideways sliding of the robotic tractor wheels either when the pull on the tongue causes the robotic tractor to be pulled to the inside of the corner or when excessive forward forces cause the robotic tractor to be pushed to the outside of the corner. This system uses the forward or backward traction of the robotic tractor wheels to control the “kinking” behavior of the robotic tractor.
The traction kinking system functions in two modes. If excessive sideways force toward the inside of the curve is sensed, the system acts to accelerate the robotic tractor and rear trailer to prevent the robotic tractor wheels from slipping toward the inside of the turn. To do this, traction kinking system activates its air motors 170 L, R (FIG. 12 ), driving the robotic tractor wheels forward. The same air pressure is supplied to both of the air motors 170 L, R, assuring that the torque on the two sides is equal. The pressure of the air that is supplied will be increased as the amount of sideways pull that is being experienced by the axle increases.
If excessive force toward the outside of the curve is sensed, the traction kinking system applies the brakes to the second trailer and to all sections behind the second trailer, acting as a jackknife prevention device. The brakes on the robotic tractor itself will not be activated by the kinking braking system.
The primary input used by the controller to manage the traction kinking system is the sideways force on the robotic tractor axle 72 (FIG. 12 ). The design of the robotic tractor axle hanger assembly 75 (FIG. 12) allows the magnitude of this sideways force to be sensed directly by the regulator valves 183 , 184 (FIG. 12 ). The regulator valves are directly activated by the sideways force and act as the control valves, sending air pressure to the traction kinking motors or activating the automatic braking system as appropriate.
The controlling microprocessor or computer 49 also keeps up with the orientation of the rear partial-circular track 512 and uses algorithms to determine the direction and/or the amount of torque needed for proper traction kinking of the robotic tractor and the back trailer. If the tractor-trailer combination rig is making a left turn, a pull to the left on the axle will indicate that the drive wheels of the robotic tractor should be speeded up, so air pressure will be applied to the traction kinking air motors 170 L, R (FIG. 12) to cause the robotic tractor to move forward faster. If the axle experiences a pull to the right during a left turn, it indicates that the trailer is moving too fast, trying to push the robotic tractor along. In this case, the brakes will be applied on both the robotic tractor and on the trailer it is supporting to slow the trailer back down and prevent the robotic tractor wheels from being pushed sideways. In a similar fashion, a pull to the left during a right turn will cause the brakes to be applied, while a pull to the right during a right turn will cause air pressure to be sent to the air motors powering the wheels.
When the robotic tractor wheels 70 R, L are close to alignment with the robotic tractor centerline, the application of forward traction will be ineffective. In this situation, the controller will reduce the amount of air pressure sent to the traction kinking motors to reduce wear and tear on the system. The traction kinking braking system need not be disabled in these situations, but could serve to activate the rear trailer braking system if the rear trailer started applying significant forward pressure to the forward trailer.
A pressurized air tank located on the robotic tractor will provide a reservoir of energy for the traction kinking system. This reservoir can store the substantial amounts of power that will be required by the air motors of the traction kinking system to accelerate the robotic tractor in tracking and cornering maneuvers. The air pressure in the tank is continuously replenished during operation by a direct supply from the tractor compressor, by a separate internal combustion engine located on the robotic tractor operating an air compressor, and/or by electric motors operating air compressors.
This traction kinking system is incorporated from Provisional Patent No. 60/179,745.
Operation of the Articulated Stinger Assembly (FIG. 10)
In the more complex embodiment of the invention, the articulated stinger assembly 500 (FIG. 10) extending backward from the trailer mounting-bar 66 (FIG. 10) provides the means to prevent the rotation of the trailer mounting-bar 66 (FIG. 10) around the kingpin of the trailer. Without some mechanism for preventing this rotation around the trailer kingpin, the readings from the sensors for the orientation of the trailer-mounting bar with respect to the robotic tractor tongue would be meaningless. This stinger 500 (FIG. 10) has locking arms 544 (FIG. 10) that can be slid backward or forward into position between the trailer structural members or between the two legs of the trailer landing gear. The locking arms 544 (FIG. 10) are then opened tightly outward against the structural members or the legs of the landing gear to lock the trailer mounting-bar 66 (FIG. 10) rigidly into place with respect to the trailer. If the configuration of the trailer is such that no substantial structural members are available, an adapter (not shown) can be provided which will allow the stinger to latch onto the sides of the trailer, with a strap going over the top of the trailer to hold the adapter in place.
FIG. 10 shows a detailed view of the articulated stinger assembly 500 (FIG. 10) that is attached to the back of the trailer mounting bar 500 (FIG. 10 ). The heavy central bar 546 (FIG. 10) of the stinger assembly is designed to withstand substantial sideways forces. The locking arms 544 (FIG. 10) slide freely forward and backward along the heavy central bar 546 , but are prevented by a stop from sliding off the end. Each locking arm 544 (FIG. 10) consists of three actuating arms 541 , 542 , 543 (FIG. 10 ), the back two of which are parallel, and a contact bar 540 (FIG. 10) with a heavy solid rubber pad that remains parallel to the heavy central bar 546 (FIG. 10) during deployment. The entire assembly is mounted to the trailer mounting-bar 66 (FIG. 10) via a spring-supported hinge 548 (FIG. 10) so that it can be easily positioned during hitching operations.
Two raised bumps just to each side of the center point on the top of each of the three partial-circular tracks mentioned above will assist the processors in keeping track of the orientation of the tracks. These raised bumps will activate switches on rollers as they pass underneath the rollers. When both switches for a given track are simultaneously activated, the processor will set the orientation to zero degrees for that track.
Physical Basis and Details of Algorithms for Path Tracking Modes, Variable Ratio with Oversteer Mode, and Combinations of Steering Modes
At this point we will attempt to describe the physical basis and the details of the algorithms that will control the steering behavior of the robotic tractor.
The data from each of the input sensors to the steering system can be transferred to the controller 49 at either fixed time intervals or fixed travel intervals. For the purposes of the algorithms used here, the data from both the lead tractor 30 and the robotic tractor is obtained on the basis of fixed travel intervals.
The data could be acquired at time intervals, then converted by the controller 49 using interpolation between data points to plot, or reference, each piece of data acquired to a pseudo-travel interval of either the lead tractor 30 drive wheels or of the steered wheels of the robotic tractor as required. Thus, each piece of data would be converted from a time basis to either a lead tractor 30 travel interval basis or a robotic tractor travel interval basis, but this system is not used in this invention.
For each travel interval, the controller 49 will acquire data from each sensor on the lead tractor 30 and/or the robotic tractor. The data from the angle sensors will be scaled to radians of rotation of the angle being measured, and the distance sensors will be scaled to feet traveled by the wheels being measured.
Calculations based on data from the lead tractor 30 will use the data that has been placed on a lead tractor 30 travel interval basis, and calculations based on data from the robotic tractor will use the data that has been placed on a robotic tractor travel interval basis. The separate reference for the linear movement of the lead tractor 30 and of the robotic tractor 50 is not a requirement of this invention, but is only used to obtain a higher degree of control.
Now the controller 49 has a set of data from each sensor, stored either on a basis of lead tractor 30 travel intervals or on a basis of robotic tractor 50 travel intervals depending on where the data originated. These numbers represent the movement of a particular encoder or the reading of a particular sensor during that travel interval. The remainder of the processing will take the form of mathematical manipulation of these numbers. The sensors used are listed here.
The angle θ R0 , between the lead tractor and the lead tractor's trailer will be positive when the lead tractor is rotated clockwise of the straight-ahead position with respect to the trailer carried by the lead tractor and negative when the lead trailer is rotated counterclockwise of the straight-ahead position. Sensor θ R0 44 will be on a lead tractor travel interval basis.
The angle θ F , which derives the angle between the lead tractor and the lead tractor steering axle from how sharply the steering wheel of the lead tractor is turned, will be positive when the steering axle is clockwise of the straight-ahead position with respect to the lead tractor and negative the steering axle is counterclockwise of the straight-ahead position. Sensor θ F 44 will be on a lead tractor travel interval basis.
The angle θ D1 44 , between the robotic tractor and the trailer in front of it, will be positive when the trailer is rotated clockwise of the straight-ahead position with respect to the tongue of the robotic tractor and negative when the trailer is rotated counterclockwise of the straight-ahead position. Sensor θ D1 44 will be on a robotic tractor travel interval basis.
The angle θ R1 81 , between the tongue of the robotic tractor and the trailer towed by the robotic tractor, will be positive when the robotic tractor tongue is rotated clockwise of the straight-ahead position with respect to the trailer carried by the robotic tractor and negative when the robotic tractor axle assembly is rotated counterclockwise of the straight-ahead position. Sensor θ R1 44 will be on a robotic tractor travel interval basis.
The angle θ S1 53 , between the robotic tractor tongue and the robotic tractor steering axle, will be positive when the steering axle assembly is rotated clockwise of the straight-ahead position with respect to the tongue and negative when the steering axle assembly is rotated counterclockwise of the straight-ahead position. Comparable sign conventions will be used for the lead tractor sensors. Sensor θ S1 44 will be on a robotic tractor travel interval basis.
The distance sensor ΔS 1 — LEFT measures the distance the left wheel of the robotic tractor travels. It is obtained from the rotation of the left axle shaft of the robotic tractor.
The distance sensor ΔS 1 — RIGHT measures the distance the right wheel of the robotic tractor travels. It is obtained from the rotation of the right axle shaft of the robotic tractor.
The distance sensor Δ S1 , measures the distance the robotic tractor travels, and is the source of the robotic tractor travel intervals. It is the average of ΔS 1 — LEFT and ΔS 1 — RIGHT .
The distance sensor Δ T , measures the distance the robotic tractor travels, and is the source of the lead tractor travel intervals. It is obtained from the rotation of the drive shaft of the lead tractor.
At the completion of each travel interval, the processor will also use the distance traveled during the interval by the robotic tractor, ΔS 1 to complete the following calculation:
SPD=[AV*SPD*DIFF Time +ΔS 1 ]/[( AV +1) DIFF Time ]
Where SPD is the average running speed, ΔS 1 is the distance traveled during the latest interval by the robotic tractor, and DIFF Time is the number of seconds of time since the last travel interrupt. The number AV is representative of the number of intervals over which the average speed is calculated. A larger AV will produce a SPD that varies more slowly with momentary velocity changes.
When the robotic tractor 50 is operating in the relative angle path tracking mode or the rate of orientation change path tracking mode, the value of each piece of data obtained from the lead tractor 30 sensors will be stored in memory in a manner that references each value to the linear position of the lead tractor 30 drive wheels at the time the value was acquired. These numbers will be recalled from memory after the robotic tractor 50 wheels have traveled a distance equal to the linear separation of the robotic tractor 50 wheels and the lead tractor 30 drive wheels.
Relative Angle Mode
In general, the relative angle mode detects the angle between the lead tractor and the first trailer at the fifth wheel, delays this angle, and causes the angle between the robotic tractor steering axle and the second trailer at the fifth wheel to match what the angle between the lead tractor and the first trailer was when they passed that point.
As shown FIGS. 2, 3 , 4 , 5 , and 6 , relative angle mode steering utilizes three angle sensors and two distance measures. The angle sensors are θ R1 81 , θ S1 53 , and θ R0 42 . The linear motion sensors are sensor ΔT 34 and sensor ΔS 1 . The ΔT's and ΔS 1 's are each summed in DIST T and DIST S1 , respectively. The combined length of the first trailer 40 and the robotic tractor tongue 55 are input into the controller 49 before starting, and the difference between DIST T and DIST S1 is initialized to be equal to this combined length. The angle θ R0 is saved with an associated reading from DIST T . When the value of DIST S1 reaches the value that DIST T had when the angle θ R0 was stored, the controller will compare the value of the angle θ S1 +θ R1 , between the steering axle assembly and the trailer being towed by the robotic tractor, to the stored value of the angle θ R0 in order to determine how much steering correction is needed. Then the hydraulic steering motor 68 will adjust the angle θ S1 +θ R1 in order to make it equal to the value that angle θ R0 had when the lead tractor passed that point.
The difference between θ R0 and θ S1 +θ R1 becomes a parameter ΔPATH 1 — Relative — Angle that will be used to correct the robotic tractor steering axle orientation to match the orientation of the lead tractor 30 drive axle(s) when they passed the same point. The controller 49 will determine the steering necessary at each robotic tractor travel interval due to this steering mode by the following calculation:
ΔPATH 1 — Relative — Angle =θ R0 — Delayed −(θ S1 +θ R1 )
For subsequent robotic tractors, the steering correction will be calculated in a very similar manner. The same equation is used. The sensors on the robotic tractor being considered are used in the equation, and the data from the lead tractor sensors is delayed an amount equivalent to the distance between the lead tractor and the robotic tractor being considered before it is used.
Rate of Orientation Change Mode
The second method of path tracking, rate of orientation change mode, measures the rate of orientation change with respect to distance traveled by the lead tractor in a horizontal plane. This information is delayed and compared to the rate of orientation change with respect to distance traveled by the robotic tractor and used for steering.
This method, as shown in FIGS. 14 and 15, utilizes the fact that the derivative with respect to distance traveled of the absolute orientation of the steering axle assembly of the robotic tractor must be equal to the derivative with respect to distance traveled of the absolute orientation of the lead tractor at the same linear position if the robotic tractor is following the path of the lead tractor. Even when we do not know the actual value of the absolute orientation of the lead tractor, this derivative can be extrapolated from the data obtained by sensor θ F 31 that detects the angle between the tractor centerline and the direction of travel of the front wheels of the lead tractor.
In rate of orientation change path-tracking mode the controller 49 calculates the change in the angle of the lead tractor 30 axle in the horizontal plane during each lead tractor travel interval. This reference information is then stored and delayed an amount equal to the number of travel intervals between the lead tractor 30 drive wheel assembly and the robotic tractor steering axle assembly 60 . The controller 49 also calculates the change in the angle of the robotic tractor axle in the horizontal plane during each robotic tractor travel interval. Then the controller 49 steers the robotic tractor to cause the rate of orientation change of the steering wheels of the robotic tractor to equal the rate of orientation change of the drive wheels of the lead tractor.
The equations for this mode can be derived using Ackerman geometry. In FIG. 14, the following variables are measured: ΔT, the distance traveled by the lead tractor in one travel interval and θ F , the angle of the front steered wheels of the lead tractor 30 with respect to the centerline of the lead tractor 30 . The LENGTH T , the distance from the center of the front steering axle of the lead tractor 30 to the center of the rear drive axle (or equivalent average drive axle if the lead tractor 30 has more than one drive axle), is known. Using the fact that we know the two measured variables and the length, we can obtain (Δ θ T )/ΔT, which is the rate of orientation change of the entire tractor with respect to distance traveled by the drive wheels of the lead tractor. The following is the derivation for (Δ θ T )/ΔT: cos θ F = R T R F 1.
From Ackerman steering definition:
Δθ T =Δθ F 2 .
R T =R F cosθ F 3 .
Δθ T R F =ΔF 4 .
R
F
=
Δ
F
Δθ
T
5.
And the same equation for the back of the tractor 30 , and substituting for R T from equation 3, is:
Δθ T R T =ΔT=ΔθR F cos θ F 6.
Rearranging and substituting for Δθ T R F from equation 5: Δ F = Δ T cos θ F 7.
From FIG. 14 : sin θ F = LENGTH T R F 8.
Substituting from equation 5: R F = LENGTH T sin θ F = Δ F Δ θ T 9.
Substituting for ΔF from equation 7: Δ θ T = Δ F sin θ F LENGTH T = Δ T tan θ F LENGTH T 10. R T = R F cos θ F = LENGTH T tan θ F 11.
Dividing both sides of equation 10 by Δ T : Δ θ T Δ T = tan θ F LENGTH T 12.
Therefore, if the travel intervals are small, the change in the angle of the lead tractor 30 drive axle is given by the equation: Δ θ T Δ T = [ tan ( θ F ) ] LENGTH T 13.
Since this calculation is performed for each travel interval, the linear distance ΔT will be equal to the length of the lead tractor 30 travel interval.
The equivalent derivation using Ackerman geometry for the robotic tractor is shown in FIG. 22 . The following variables are measured: ΔS 1 , the distance traveled by the steering axle of the robotic tractor; θ D1 , the angle between the centerline of the forward trailer and the centerline of the robotic tractor tongue; θ S1 , the angle between the centerline of the robotic tractor tongue and the centerline of the robotic tractor steering axle assembly 60 ; and LENGTH D1 , the length of the robotic tractor tongue from the hitch point of the first robotic tractor 50 to the center of the steering axle assembly as measured along the centerline of the robotic tractor 50 . Using the four known variable values, you can obtain (Δ θ S1 )/ΔS 1 which is the rate of orientation change of the robotic tractor with respect to distance traveled by the robotic tractor steering axle assembly. The following is the derivation for (Δ θ S1 )/ΔS 1 : m + π 2 - θ D1 + π 2 + θ S1 = π 14. m−θ D1 +θ S1 =0 15.
m=θ D1 −θ S1 16.
Using the law of sines and substituting from equation 16: LENGTH D1 sin m = LENGTH D1 sin ( θ D1 - θ D1 ) = R R sin ( π 2 + θ S1 ) 17. R R ′ = ( LENGTH D1 * sin ( π 2 + θ S1 ) sin ( θ D1 - θ S1 ) ) 18.
Using the same proess to determine R D : R D ′ = LENGTH D1 * sin ( π 2 - θ D1 ) sin ( θ D1 - θ S1 ) 19.
Using Ackerman geometry: Δ θ S1 = Δ θ D1 = Δ S 1 R D ′ = Δ S 1 * [ sin ( θ D1 - θ S1 ) [ LENGTH D1 ] * sin ( π 2 - θ D1 ) ] 20.
Using the trigonometric identity and substituting: Δ θ S1 = Δ S 1 LENGTH D1 * [ sin ( θ D1 - θ S1 ) cos θ D1 ] 21.
If the travel intervals are small between samples, the equation for the change in the angle of the robotic tractor 50 steering axle assembly 60 is: Δ θ S1 Δ S 1 = ⌊ sin ( θ D1 - θ S1 ) ⌋ ( LENGTH D1 ) * cos ( θ D1 ) 22.
where ΔS 1 is the linear distance traveled by the wheels of the first robotic tractor 50 , LENGTH D1 is the length between the first robotic tractor 50 hitch point and the center of the steering axle assembly as measured along the robotic tractor 50 centerline, θ D1 is the angle between the centerline of the first trailer and the centerline of the first robotic tractor 50 , and θ S1 is the angle between the perpendicular to the first robotic tractor 50 steering axles and the centerline of the robotic tractor 50 . Again, since the data is referenced to each robotic tractor 50 travel interval, the value of ΔS 1 will be equal to the robotic tractor 50 travel interval. Now, since the value of θ S is under the direct control of the controller 49 , it can be directly adjusted until the value of Δ θ S1 matches the value Δ θ T had at that point in its linear travel.
Let θ F,DEL =the delayed θ F 23.
then
Δθ T,DEL =Δθ S1 24.
(to make dolly steering axle track drive wheels of tractor) Δ T * tan θ F , DEL LENGTH T = Δ S 1 LENGTH D1 * [ sin ( θ D1 - θ S1 ) cos θ D1 ] 25. Δ R R R ′ = Δ S 1 R D ′ 26. Δ R = Δ S 1 * ( R R ′ R D ) = Δ S 1 * [ LENGTH D1 * sin ( π 2 + θ S1 ) LENGTH D1 * sin ( π 2 - θ D1 ) ] = Δ S * ( cos ( - θ S1 ) cos θ D1 ) 27. sin ( θ D1 - θ S1 ) = ( LENGTH D1 LENGTH T ) * ( Δ T Δ S 1 ) * tan θ F , DEL * cos θ D1
28. θ S1 = θ D1 - arcsin [ ( LENGTH D1 LENGTH T ) * tan θ F , DEL * cos θ D1 ] 29.
The delta needed to steer the dolly Δ Rate — of — Orientation is then
θ S1 — calculated −θ S1 — measured =Δ Rate — of — Orientation 30.
Δ
Rate_of
_Orientation
=
θ
D1
-
θ
S1
-
arcsin
[
(
LENGTH
D1
LENGTH
T
)
*
tan
θ
F
,
DEL
*
cos
θ
D1
]
31.
After having determined the rate of orientation change with respect to distance traveled for both the lead tractor (FIG. 21) and robotic tractor (FIG. 22 ), the controller 49 will determine the steering correction provided by this rate of orientation change mode necessary at each first robotic tractor 50 travel interval by the following calculation: Δ PATH Rate_of _Orientation = θ D1 - θ S1 - arcsin [ ( LENGTH D1 LENGTH T ) * ( tan θ F_Delayed ) * ( cos θ D1 ) ]
θ F — DELAYED is the angle between the front steered wheels of the lead tractor 30 and the lead tractor 30 centerline [delayed an amount equal to the linear distance between the lead tractor 30 drive wheels and the robotic tractor 50 wheels (empirically corrected with a response time correction, if needed)], and where θ S1 and θ D1 are defined as above. For subsequent robotic tractors, the steering correction will be calculated in a very similar manner. The same equation is used. The sensors on the robotic tractor being considered are used in the equations, and the data from the lead tractor sensors is delayed an amount equivalent to the distance between the lead tractor and the robotic tractor being considered before it is used.
Variable Ratio with Oversteer Mode
The variable ratio (with oversteer) mode of steering is an non-path-tracking mode that has been derived in a way that allows it to be used in combinations with the path tracking modes. This steering method is disclosed in U.S. patent application Ser. No. 09/721,214. This method does not rely on any information from the tractor 30 sensors, but only on sensors on the robotic tractor 50 itself. This method compliments the path tracking modes, each compensating for possible weaknesses in the other. This alternate steering mode can be used to factor into one or more of the path tracking modes. The variable ratio steering algorithm reacts more strongly the farther out of line the wheels slip, thereby automatically correcting the path back to the approximate path of the first trailer. The variable ratio (with oversteer) mode uses sensors θ S1 , θ D1 , ΔS 1 — LEFT and ΔS 1 — RIGHT and θ R1 .
The difference between the counts for the two wheels will be scaled to yield a measure of the amount of cornering that the robotic tractor wheels are undergoing. This difference is accumulated and then decayed at a prescribed rate per linear foot of travel, and is used along with the input from sensor θ R1 as input to the oversteer logic system. The controller 49 will maintain two decayed running totals of the difference between the travel of the left wheel and the travel of the right wheel.
DIFF L — R =DIFF L — R +(ΔS 1 — LEFT −ΔS 1 — RIGHT )−DECREMENT
And
DIFF R — L =DIFF R — L +( ΔS 1 — RIGHT −ΔS 1 — LEFT )−DECREMENT
Where DIFF L — R is the decayed running total of the difference between the travel of the left wheel 71 L minus the travel of the right wheel 71 R, and DIFF R — L is the decayed running total of the difference between the travel of the right wheel 71 R minus the travel of the left wheel 71 L. Also, ΔS 1 — LEFT is the travel of the left wheel 71 L in the latest travel interval and ΔS 1 — RIGHT is the travel of the right wheel 71 R in the latest travel interval. The number DECREMENT represents the amount of decay in each travel interval and can be adjusted as needed to change the oversteer characteristics of the system. Generally any accumulation in the delayed running totals DIFF L — R and DIFF L — R should decay within less than 100 feet or so to zero. At the end of any travel interval in which DIFF L — R is less than zero, we will set DIFF L — R =0. At the end of any travel interval in which DIFF L — R is less than zero, we will set DIFF L R =0.
The steering ratio for the variable ratio mode could be varied as a function of turning angle, speed, or any other such variable, but for simplicity, we will demonstrate how the steering ratio would be varied continuously by the processors as the speed of the robotic tractor changes. At higher speeds, the controller 49 will automatically control the robotic tractor in a manner that is more stable (a more positive steering ratio), and at lower speeds, the processors will automatically control the robotic tractor in a manner that has better cornering ability (a more negative steering ratio). In order to accomplish this we will choose a correction factor, CORR, which is dependent upon the average speed of the robotic tractor. A steering ratio of −4 produces very responsive steering and a steering ratio of about +0.6 (depending upon the ratio of the robotic tractor length to the length of the robotic tractor and the rear trailer 80 together) produces very stable steering. If we wanted to vary the correction factor CORR linearly between −4 and +0.6 as the speed increased from 8 ft/sec to 30 ft/sec, we would use the equation:
CORR=(0.2091*SPD)−5.673
whenever
8<SPD<30 ft/sec.
If SPD was less than 8, then we would set:
CORR=−4
for
SPD<8 ft/sec.
And if SPD was greater than 30, we would set:
CORR=0.6
for
SPD>30 ft/sec.
CORR could also be a constant, or varied according to any method desired.
ΔRATIO 1 is the steering output from the variable ratio (with oversteer) mode, the processor will then determine the steering output at each robotic tractor travel interval by the following calculation:
ΔRATIO 1 =[θ D1 +(FAC 1 )(θ R1 )+(FAC 2 )(DIFF L-R −DIFF R-L )]*(CORR)−θ S1
where FAC 1 and FAC 2 are the oversteer factors for the trailer orientation system and the accumulated robotic tractor wheel delayed difference system respectively, and ΔRATIO 1 is the amount of movement determined by the variable ratio component of the steering algorithms to be needed by the axle steering system.
Methods for Combining Modes, and Advantages of Such Combinations
For the preferred embodiment of the invention, a non-path-tracking steering mode, the variable ratio (with oversteer) mode will be combined with the path tracking modes. This combination will help to assure that any errors that enter into the steering operation are not propagated in a way that will cause instabilities or offsets.
The variable ratio (with oversteer) mode is actually a non-path tracking mode of steering that can be combined with the path tracking modes of steering. In this capacity it will help to ensure that any errors that enter the system through wheel slippage, inaccuracies in measurements, or anything else are quickly and smoothly eliminated before problems develop. The variable ratio type of steering is particularly useful for eliminating any offset between the centerlines of the lead tractor-trailer combination and the robotic tractor-trailer combination.
The contribution from this variable ratio (with oversteer) mode of steering has a somewhat different character at different speeds. As the speed increases, the steering ratio will become positive and the contribution from the variable ratio with oversteer mode will become a more stable type of ratio steering, like a steerable type A dolly, increasing steering stability. As the speed decreases, the steering ratio will become negative to produce a cornering type of ratio steering including oversteer.
The controller 49 can be programmed to use any combination of the Path Tracking, and/or cornering or stability ratio steering modes under various speed and/or cornering conditions. The mixture can easily be adjusted to obtain the desired steering characteristics.
This variable ratio with oversteer mode of steering can be easily integrated with the path tracking modes of steering, since the modes all have output in the form of a Δ which is the correction to the steering angle that is needed. For example, if equal weight was given to each of the two path tracking modes (relative angle mode and rate of orientation change mode) and to the Variable Ratio with oversteer mode of steering, each type of steering would contribute roughly one-third of the total steering character. When the robotic tractor 50 is operating in this combined mode, the controller 49 will determine the steering necessary at each first robotic tractor travel interval by a calculation similar to the following:
ΔFINAL=[ΔRATIO 1 +ΔPATH 1 — Relative — Angle +ΔPATH 1 — Rate — of — Orientation ]/3
where ΔRATIO 1 , ΔPATH 1 — Relative — Angle , and ΔPath 1 —Rate — of — Orientation are defined as above. Also, any of the modes can easily be combined with any of the other modes. For example, a simple combination of the two path tracking modes with equal weightings could be obtained by setting
ΔFINAL=(ΔPATH 1 — Relative — Angle +ΔPath 1 —Rate — of —Orientation )/2
The output from the steering modes could be weighted according to the speed of the vehicle, the steering angle of the lead tractor, the angle between any two section, under the control of the driver of the lead tractor, or using input from many different systems. The output from the steering modes could be combined using many methods, and it is expected that, they would all be covered under this invention.
Referring to the equations that were derived for the variable ratio (with oversteer) portion of the above controlling equation, we can see how this combination contributes to the stability of the system at high speeds. When CORR is near 0.6 the two path-tracking modes will be combined with a very stable form of the variable ratio mode (steering ratio positive). When CORR is closer to −4 the more maneuverable cornering mode (steering ratio negative) will be combined with the path-tracking modes.
As above, ΔFINAL is the amount of steering correction needed by the axle steering system. During operation, the steering motors should act to maintain ΔFINAL near zero. The value of ΔFINAL controls the activation of hydraulic control valves that cause the hydraulic motor 68 (FIGS. 4, 5 ) to rotate the steering axle assembly 60 about its central pivot support point 58 (FIG. 3 ). A positive value of ΔFINAL will cause the wheels to be steered more to the right of the robotic tractor centerline, and a negative ΔFINAL will cause them to be steered more to the left of the robotic tractor centerline. A larger magnitude of ΔFINAL will cause the valves to be opened wider or will cause more than one valve to be opened, producing more rapid steering movement.
Miscellaneous Topics
Smoothing Steering Behavior
It should be noted that if experimental error in the measurements was causing the steering to become erratic during operation, the steering response could be smoothed by simply averaging ΔFINAL over several travel intervals.
Improving General Steering Response
It should also be noted that in each of the above cases, steering response could be improved by having an algorithm for the controller 49 to predict the value of the variables in the next travel interval by extrapolation of the input values for the last two or three travel intervals. It could then control the steering motors so that when the actual data for the interval was obtained, the value of ΔFINAL would be minimized. Obviously, the steering response will also be improved if the controller 49 uses the smallest travel interval that it is able to use. The travel interval size could be changed occasionally as the speed changed in order to improve the response of the system at lower speeds.
Backing Mode
The behavior of the robotic tractor with path tracking steering modes, variable ratio (with oversteer) mode, and traction kinking during backing operations is of particular interest. Normally a double is almost impossible to back, but if the robotic tractor is shifted into a special stability mode (corresponding to full control by the stability portion of the variable ratio steering mode), the robotic tractor with its trailer will behave much like a single-axle trailer with a very long wheelbase. The double string will then become only slightly harder to back than a single trailer.
Multiple Robotic Tractors
It should be noted that, while the analysis presented here applies to all robotic tractors in a given truck-tractor string. In general, with the robotic tractors incorporating the improvements of this invention, one tractor will pull and control several robotic tractors with their trailers. The algorithms for the various modes of path tracking for the second robotic tractor function the same as those for the first robotic tractor, with the sensor readings from the main tractor must be delayed longer due to the greater distance between the robotic tractor and the lead tractor.
Most of the algorithms could also be made to function for more robotic tractors by taking the readings off of the robotic tractor in front of the one being considered, instead of the lead tractor, but that would cause errors to propagate more readily. The ratio with oversteer mode must take readings from the unit directly in front of it, however combining this method with the other modes will correct for that additional error.
Length Adjustments
The length of the robotic tractor may need to be adjusted to accommodate rear trailers 58 of different lengths. This may be accomplished by loosening the pins and locks 146 and 148 , sliding the inner section of the frame 74 b into or out of the outer frame section 74 a at joint 144 , and then re-tightening the pins and locks 146 and 148 .
Generality of Concept
The concepts involved in this invention are most easily explained by describing specific devices that embody or exemplify these concepts. The construction of the various sensors and control components shown in the preferred embodiment of the invention was chosen more with the intention of making each part of the invention understandable than for practicality of construction and use. More compact angle sensors and rotation sensors are readily available, and an expert in the field will quickly see that, in almost all cases, the invention could easily be constructed using any device that performs the desired function. The description of any particular embodiment of the invention is not intended in any way to limit the invention to some particular embodiment, but only to assist the reader in understanding the concepts involved in this invention. It is, therefore, to be understood that the present invention includes any embodiment that is within the scope of the claims rather than as specifically described.
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A method and apparatus for controlling the steering of a trailing section of a multi-sectioned vehicle is described. The trailing section follows the path of the first section. Data is acquired by a controller from sensors on the various sections. The controller then processes this data, generating a configuration needed for the controller-steered wheels to follow a path approximately equivalent to the path taken by the first steered section. Power is then applied by some means to steer these controller-steered wheels, forcing them into the desired configuration. The complexity of the control system can be varied with different algorithms providing alternative steering patterns as desired. This system can be extended with more trailing sections without necessitating more than minor changes to the control algorithms.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2008-0043731 filed May 13, 2008, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] (a) Technical Field
[0003] The present invention relates to an end plate for a fuel cell stack and a method of manufacturing the same. More particularly, the present invention relates to an end plate for a fuel cell stack and a method of manufacturing the same, wherein said end plate and manufacturing method can increase flexural rigidity per weight, strain at break, and reduce heat transmission by employing a sandwich structured end plate having a hybrid core combined with honeycomb and foam.
[0004] (b) Background Art
[0005] A polymer electrolyte membrane fuel cell or a proton exchange membrane fuel cell (“PEMFC”) generates electricity by electrochemically reacting hydrogen and oxygen. The PEMFC has better efficiency, greater current and output density, smaller starting time and faster response to load changes than other types of fuel cells.
[0006] A membrane-electrode assembly (“MEA”) is disposed at the most inner part of a fuel cell unit. The MEA conventionally includes a solid polymer membrane layer, through which hydrogen protons pass, and catalyst layers coated on both surfaces of the membrane layer to react hydrogen and oxygen. The catalyst layer includes a cathode and an anode.
[0007] Preferably, a gas diffusion layer (“GDL”) and a gasket are disposed at the outermost part of the membrane where the cathode and the anode are disposed. A separator having a flow field is disposed ton the outside of the GDL to provide fuel and exhaust water. An end plate is combined at the most outer part to support the above elements.
[0008] Thus, at the anode of the fuel cell, a hydrogen ion and an electron are generated by oxidation of the hydrogen. The generated hydrogen ion and the electron are moved to the cathode through the membrane layer and the separator, respectively.
[0009] Water is generated at the cathode by the electrochemical reaction of the hydrogen ion and the electron, which are moved from the anode, and oxygen which is contained in the air. Electrical energy is generated from such flow of the electron.
[0010] In the fuel cell stack, the end plate serves to support components while maintaining uniform surface pressure exerted on each component. . . . In addition, the end plate serves to minimize heat loss and stabilize temperature in the fuel cell stack in a short period, so that the fuel cell has considerable cold startability.
[0011] Maintaining a uniform surface pressure to each component in the stack is important to prevent leakage of liquid inside the stack and also to prevent increase of electrical contact resistance between cells.
[0012] In addition, a smaller thermal conductivity of the end plate is advantageous in preventing heat loss from the stack, and maintaining a constant temperature of the stack.
[0013] A conventional end plate includes stainless-steel to sustain the uniform surface pressure. However, as the weight of an end plate made of stainless steel exceeds 7 to 8 kilograms, handling the end plate becomes difficult. Further, since the metal is not suitable for insulation of heat, the cold start property deteriorates.
[0014] Thus, the properties of the end plate that make contact with the separator of the fuel cell stack, have been investigated concerning the materials, designs and manufacturing processes for making an end plate that is suitably lighter and has proper flexural rigidity and suitably lower thermal conductivity in order to improve cold start.
[0015] Accordingly, an end plate having a sandwich structure has been described, and a method for manufacturing the core element of the sandwich-structured end plate includes suitably expanding foams into a honeycomb member to resist compression and shock.
[0016] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY
[0017] In one aspect, the present invention is directed to an end plate for a fuel cell stack comprising: a core element with a honeycomb comprising one or more cells filled with foam; and a plate element attached to the core element while covering the same, wherein the foam filled in the cell of the honeycomb is an expanded foam or a closed cell foam.
[0018] In a preferred embodiment, the foam is further furnished with thermal insulating means.
[0019] In another preferred embodiment, the thermal insulating means comprises thermoplastic resin which is suitably coated and cured at an outer surface of the honeycomb or the foam.
[0020] In still another preferred embodiment, the thermal insulating means comprises carbon dioxide that is preferably injected into the foam while foaming the foam within each cell of the honeycomb.
[0021] In still another preferred embodiment, the cells of the honeycomb are filled with an upper closed cell foam and a lower closed cell foam, wherein the thermal insulating means preferably comprises a carbon dioxide gas layer or a aerogel sheet, the thermal insulating means being interposed between the upper closed cell foam and the lower closed cell foam.
[0022] In still another preferred embodiment, the thermal insulating means includes a plurality of porous holes suitably formed at walls of each cell of the honeycomb, a vacuum providing mean provided to the filled foam in the honeycomb through the holes and a thermoplastic material suitably melted by heating to be filled into the holes.
[0023] In another aspect, the present invention provides a method of manufacturing an end plate for a fuel cell stack, comprising steps of: mounting honeycomb within a box type element with a substantially box shape having an upper opening; disposing expanded foam material on the honeycomb; and forcibly inserting the expanded foam material into each cell of the honeycomb.
[0024] In a preferred embodiment, the method further comprises steps of coating resin to the honeycomb or the foam and suitably curing the resin.
[0025] In still another aspect, the present invention provides a method of manufacturing an end plate for a fuel cell stack, comprising steps of: placing a foam material in each cell of a honeycomb; expanding the foam material such that each cell is filled with the expanded foam; and injecting carbon dioxide into the foam material while the foam material is expanded.
[0026] In yet another aspect, the present invention provides a method of manufacturing an end plate for a fuel cell stack, comprising steps of: mounting honeycomb within a box type element with a substantially box shape having an upper opening; forcibly inserting a lower closed cell foam into each cell of the honeycomb; providing an thermal insulating layer on the lower closed cell foam, the insulating layer preferably being carbon dioxide gas layer or aerogel sheet; and forcibly inserting a upper closed cell foam into each cell of the honeycomb.
[0027] In still yet another aspect, the present invention provides a method of manufacturing an end plate for a fuel cell stack, comprising steps of: preparing a honeycomb having a plurality of porous holes formed at walls of each cell thereof, the honeycomb including thermoplastic material disposed at walls of cells, which are positioned at corners; disposing expanded foam on the honeycomb; forming a core element by forcibly inserting the expanded foam material into each cell of the honeycomb; adhering plate elements to an upper and lower surfaces of the core element; and vacuum packing the core element to suitably generate vacuum inside the foam of the honeycomb.
[0028] In a preferred embodiment, the method further comprises a step of heating the vacuum packed core element to suitably melt the thermoplastic material and to fill up the porous holes of the honeycomb.
[0029] According to the present invention, a core element for an end plate is easily manufactured by suitably pressing constantly deposited honeycomb and foam to insert the foam into the honeycomb, or suitably expanding the foam in the honeycomb. The end plate is preferably applied as a sandwich hybrid material, so that weight is lightened and proper flexural rigidity is obtained when combined to the fuel cell stack. Thus, uniform surface pressure to the stack is maintained.
[0030] Moreover, additional thermal insulating means is applied to the honeycomb or the foam, so that thermal insulation is improved, thereby, the fuel cell stack is operated well even when cold start. Thus, the efficiency of the fuel cell is suitably improved.
[0031] It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum).
[0032] As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered.
[0033] The above features and advantages of the present invention will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description, which together serve to explain by way of example the principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated by the accompanying drawings which are given hereinbelow by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0035] FIGS. 1A and 1B are vertical cross-sectional view and horizontal cross-sectional view illustrating an end plate for fuel cell stack of the present invention;
[0036] FIG. 2 is a schematic diagram showing a method for manufacturing an end plate in accordance with a first embodiment of the present invention;
[0037] FIG. 3 is a schematic diagram showing a method for manufacturing an end plate in accordance with a second embodiment of the present invention;
[0038] FIG. 4 is a schematic diagram showing a method for manufacturing an end plate in accordance with a third embodiment of the present invention;
[0039] FIG. 5 is a schematic diagram showing a method for manufacturing an end plate in accordance with a fourth embodiment of the present invention; and
[0040] FIGS. 6 and 7 are graphs presenting physical properties of a honeycomb-foam core element.
[0041] Reference numerals set forth in the Drawings includes reference to the following elements as further discussed below:
[0000]
10: plate element
12: box type element
20: core element
21: honeycomb
22: foam
23: cell space
24: thermal insulation layer
(carbon dioxide layer or
aerogel sheet)
26: hole
28: thermoplastic material
30: vacuum bag
40: adhesive agent
[0042] It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
[0043] In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
DETAILED DESCRIPTION
[0044] As described herein, the present invention includes an end plate for a fuel cell stack comprising a core element with a honeycomb comprising one or more cells filled with foam; and a plate element attached to the core element. In preferred embodiments, the plate element is attached to the core element, while covering the same. In further preferred embodiments, the foam filled in the cell of the honeycomb is an expanded foam or a closed cell foam. In another preferred embodiment, the foam is further furnished with thermal insulating means.
[0045] The invention also includes a method of manufacturing an end plate for a fuel cell stack, comprising the steps of forming a core element having a honeycomb filled with foam; and adhering a plate element to the core element so as to enclose entire or partial surface of the core element.
[0046] In a preferred embodiment of the method, forming a core element having a honeycomb filled with foam further comprises disposing expanded foam material on a honeycomb and forcibly inserting the foaming material into each cell of the honeycomb, or expanding foam material within each cell of the honeycomb.
[0047] Hereinafter reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
[0048] FIGS. 1A and 1B are exemplary vertical cross-sectional views and horizontal cross-sectional views illustrating an end plate for a fuel cell stack of the present invention.
[0049] In certain embodiments, the end plate of the present invention is preferably formed as a sandwich structure having a core element 20 and plate elements 10 which are suitably disposed at upper and lower parts of the core element 20 . The core element 20 is preferably composed of a honeycomb 21 and a foam 22 .
[0050] In certain embodiments, the plate element 10 of the end plate may preferably include metallic material, composite material with filler, fiber reinforced composite material, polymer material, etc.
[0051] In other embodiments, the core element 20 preferably includes the honeycomb 21 and the foam 22 , and the honeycomb 21 may suitably include, but is not limited to, aluminum honeycomb, glass fiber honeycomb, various plastic honeycombs and so on. The foam 22 may preferably include low thermal conductivity material such as, but not limited to, polyvinyl chloride (“PVC”), polyethylene terephthalate (“PET”), poly styrene (“PS”), poly urethane (“PU”) and so on.
[0052] Preferably, the plate element 10 and the core element 20 are suitably adhered by an adhesive agent 40 which is glued on a boundary surface between the plate element 10 and the core element 20 .
[0053] As illustrated in FIGS. 6 and 7 , an end plate consisting of only honeycomb shows superiority in flexural rigidity, and on the other hand an end plate consisting of only foam material shows superiority in strain at break. Thus, the end plate according to the present invention, which combines the honeycomb and the foam material, has well-balanced physical properties of flexural rigidity and strain at break.
[0054] In a method of manufacturing an end plate in accordance with a first preferred embodiment of the present invention, a core element is suitably manufactured by a press-insert method.
[0055] In one embodiment, the end plate with a sandwich structure, which preferably includes the core element and the plate element adhered to both surfaces of the core element, is suitably manufactured as the following method.
[0056] FIG. 2 is a schematic diagram showing an exemplary method for manufacturing an end plate in accordance with a first embodiment of the present invention.
[0057] In exemplary embodiments, the core element 20 preferably has a combination structure of a honeycomb 21 and a foam 22 . The honeycomb 21 is preferably formed as a plurality of cell structures. In certain embodiments, the cell structures preferably include a thin plate, and are extended in a substantially vertical direction as a substantially hexagonal shape. A honeycomb structure has considerably high resistance against compression and the foam is a suitable material having a considerably low density. Preferably, by using such characteristics of the honeycomb and the foam, the foam may be easily inserted into each cell of the honeycomb. In particular embodiments, the foam material can be easily inserted into each cell space 23 of the honeycomb 21 by suitably pressing the foam 22 material using a press (not shown) after suitably disposing the expanded foam 22 material with low density of about 40 to 50 kg/m 3 on the honeycomb 21 that is seated within a box type element 12 having an upper opening.
[0058] In preferred embodiments, the core element having a sandwich structure combined with the honeycomb and the foam may be manufactured, preferably by pressing the foam material after manufacturing separately and suitably depositing the honeycomb 21 and the foam 22 .
[0059] In exemplary embodiments, the plate element 10 is preferably adhered by the adhesive agent 40 on the upper surface of the core element 20 , at which the foam 22 may be suitably inserted into each cell space 23 . The end plate is formed as the entire core element 20 is suitably surrounded by the plate element 10 and the box type element 12 . The end plate is preferably formed with the honeycomb 21 and the foam 22 , so that the weight is small and has thermal conductivity. Thus, a cold start is improved by the end plate, and the end plate has suitable flexural rigidity.
[0060] In preferred embodiments, in order to increase rigidity in a plate direction as well as in a thickness direction of the core element 20 , the foam 22 or the honeycomb 21 material is preferably dipped in resin, and the foam 22 and honeycomb 21 are preferably inserted into each cell space 23 , for example, by pressing as described above, and the resin is suitably cured. Thus, in further embodiments, the core element having both good points of the honeycomb and the foam and increasing the rigidity in the plate direction may be manufactured.
[0061] According to preferred embodiments, the resin coated at outer surfaces of the foam the honeycomb preferably functions as a lubricant, which helps the foam 22 to insert into each cell space of the honeycomb 21 . In other further embodiments, the resin preferably functions as an adhesive agent to adhere the honeycomb and the foam firmly, and the resin functions as a thermal insulator.
[0062] In an exemplary method for manufacturing an end plate in accordance with a second preferred embodiment of the present invention, a foam is inserted in each cell of a honeycomb, and is suitably expanded.
[0063] FIG. 3 is a schematic diagram showing an exemplary method for manufacturing an end plate in accordance with a second embodiment of the present invention.
[0064] As illustrated in FIG. 3 , the foam 22 is suitably inserted into each cell space 23 of the honeycomb 21 , and the foam material is suitably expanded by an expanding device (not shown). The core element 20 , at which the foam 22 is expanded and filled into each cell space 23 of the honeycomb 21 , is manufactured.
[0065] In order to lower thermal conductivity of the end plate, according to further embodiments, an additional carbon dioxide layer is formed by preferably inserting carbon dioxide into the foam 22 material when expanding the foam 22 material or preferably inserting carbon dioxide, which is thermal insulator, into surfaces of the foam after expanding.
[0066] The initial thermal insulation performance is suitably maintained when carbon dioxide is not escaped from the foam at both cases.
[0067] Preferably, walls of the core element 20 are partitions of the cell space of the honeycomb, so that carbon dioxide is suitably blocked from leaking gas. However, in further preferred embodiments, the upper and lower walls of the core element 20 are opened. Thus, the plate element 10 with box shape as illustrated in exemplary FIG. 3 is adhered at entire surfaces of the core element 20 to be sealed, so that leaking gas of the carbon dioxide thermal insulation layer to the air is suitably prevented.
[0068] The carbon oxide has suitably low thermal conductivity as presented in table 1, so that thermal insulation is improved.
[0000]
TABLE 1
Thermal conductivity (W/mK)
SUS
16.3
Polyurethane Foam
0.09
carbon dioxide
0.0144 (@ −20° C.)
Air
0.0235 (@ −20° C.)
Aerogel
0.01
[0069] In an exemplary method for manufacturing an end plate in accordance with a third preferred embodiment of the present invention, the same method as the first embodiment is proceeded, but dry ice or aerogel sheet is preferably used to improve thermal insulation effect.
[0070] FIG. 4 is a schematic diagram showing a preferred method for manufacturing an end plate in accordance with a third embodiment of the present invention.
[0071] In one embodiment, the honeycomb 21 is suitably mounted in the box type element 12 with a substantially box shape having an upper opening, and the foam 22 preferably including high density closed cell on the honey comb 21 . Preferably, the foam 22 having the closed cell is inserted easily into each cell space of the honeycomb 21 by pressing the foam 22 .
[0072] According to further embodiments, the foam 22 having the closed cell is suitably filled into each cell space of the honeycomb 21 . Preferably, dry ice is inserted on the foam 22 as thermal insulation layer to generate carbon dioxide layer, or the foam 22 having the closed cell is suitably pressed and inserted on an aerogel sheet after the aerogel sheet is inserted on the foam 22 .
[0073] Preferably, the aerogel sheet has low thermal conductivity as presented in table 1, so that thermal insulation is improved.
[0074] Preferably, the plate element 10 is adhered with adhesive agent 40 and suitably sealed to the entire surfaces of the core element 20 , so that gas of the carbon dioxide layer is prevented from leaking to the air.
[0075] In an exemplary method for manufacturing an end plate in accordance with a fourth preferred embodiment of the present invention, the same method as the first embodiment is proceeded, but the thermal conductivity of the end plate is suitably lowered by using vacuum.
[0076] FIG. 5 is a schematic diagram showing a preferred method for manufacturing an end plate in accordance with a fourth embodiment of the present invention.
[0077] Preferably, about 40 to 50 kg/m 3 of the expanded foam 22 material with low density is suitably disposed on the honeycomb 21 , and the foam 22 material is pressed by the press. Accordingly, the core element 20 , at which the foam 22 material is easily inserted into each cell space of the honeycomb 21 , is manufactured.
[0078] In further embodiments, a plurality of porous holes 26 is suitably formed at walls of the cell space of the honeycomb 21 , and preferably thermoplastic material 28 is suitably inserted at corner part of the cell walls of the honeycomb.
[0079] In exemplary embodiments, after the plate element 10 is adhered with adhesive agent 40 to the entire surfaces of the core element 20 , and in further embodiments the inside is vacuumed by packing with a vacuum bag 30 . Accordingly, the foam in the core element 20 is suitably vacuumed through the porous holes 26 of the honey comb 21 .
[0080] In other exemplary embodiments, in order to suitably maintain vacuum state, the vacuum packed end plate is preferably heated, thereby, the thermoplastic material 28 is melted and fills the porous holes 26 of the honeycomb at the corner. Thus, the vacuum state in the core element is suitably maintained, and the thermal insulation effect is obtained by the vacuum state.
[0081] As described the above, the end plate of the present invention preferably applies light foam filled honeycomb as an exemplary core element, and can include various suitable thermal insulating means. Accordingly, the end plate as described herein is lighter and has higher thermal resistance to provide an improved cold start. Moreover, the end plate as described by the invention has suitable rigidity so as to provide uniform stack surface pressure.
[0082] The invention has been described in detail with reference to preferred embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
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The present invention provides an end plate for fuel cell stack and a method for manufacturing an end plate, which can increase flexural rigidity per weight, and improve strain at break, and reduce heat transmission by applying hybrid core element having honeycomb and form structures to an end plate having sandwich structure combined to both end portions of a fuel cell stack.
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BACKGROUND
The present invention relates to a device and method for selecting between spring rates in a single lock set assembly that supports multiple lockset trim types.
A conventional door knob has a center of mass centered with the axis of the lock spindle. A conventional door lever, in contrast, has a center of mass offset some distance from the spindle axis. The gravitational force on this center of mass produces a torque about the spindle axis. To provide a counter torque to maintain the neutral position of the lever in a horizontal plane and to also resist increased operator torque due to the inherent mechanical advantage afforded a lever, a stiffer spring or additional springs are typically included in lock assemblies on which a lever will be installed. This is usually accomplished by manufacturing two separate lock assembly configurations: one with lighter springs for knobs, and a second one with heavier springs for levers.
SUMMARY
In one embodiment of a latch assembly configured to attach to a door, the latch assembly includes one of a knob and a lever. The latch assembly further includes a latch extending from the door. A spindle is rotatable from a first position to a second position to move the latch from an extended position to a retracted position. A first biasing member is selectively operable to bias the spindle toward the first position. A second biasing member is selectively operable to bias the spindle toward the first position. An actuator is movable between a knob position in which only one of the first biasing member and the second biasing member biases the spindle toward the first position and a lever position in which both the first biasing member and the second biasing member cooperate to bias the spindle toward the first position.
In one embodiment of a latch assembly configured to attach to a door, the latch assembly includes a latch extending from the door. A housing is coupled to the door and has an aperture defining a central axis therethrough. A spindle is received and configured to rotate within the aperture and to extend and retract the latch. First and second biasing springs are contained within the housing. An actuator is selectively movable to an operable position in which rotation of the spindle deflects the first and second biasing spring, and an inoperable position in which rotation of the spindle deflects only the first biasing spring.
In one embodiment of a latch assembly configured to attach to a door, the latch assembly includes a spindle rotatable about a central axis to move a latch from an extended position to a retracted position in the door. An annular plate is fixed with respect to the door and includes a slot, a first face, and a projection extending from the first face. A retainer member includes a first face, a first protrusion extending from the first face, and a second protrusion extending from the first face. The retainer member is coupled to the spindle and rotatable about the central axis. A first spring is disposed between the first face of the annular plate and the first face of the retainer member. A second spring is disposed between the first face of the annular plate and the first face of the retainer member. The first and second springs are movable with the projection, the first protrusion, and the second protrusion. An actuator is selectively movable between a retracted position and an extended position through the slot to place the first and second springs into a mechanically parallel relationship.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a lock assembly having a lever handle.
FIG. 2 a is a perspective view of a selectable lock assembly with a knob handle.
FIG. 2 b is a perspective view of the selectable lock assembly of FIG. 2 a with a lever handle.
FIG. 3 a is an exploded view of the selectable lock assembly of FIGS. 2 a and 2 b.
FIG. 3 b is an exploded view of the selectable lock assembly of FIGS. 2 a and 2 b.
FIG. 3 c is another perspective view of the selectable lock assembly of FIGS. 2 a and 2 b.
FIG. 4 is an end view of the selectable lock assembly of FIGS. 2 a and 2 b in a neutral position.
FIG. 5 a is a perspective view of the selector of the selectable lock assembly of FIGS. 2 a and 2 b.
FIG. 5 b is a perspective view of the positioning member of the selector of FIG. 5 a.
FIG. 6 a is a section view taken along line 6 a - 6 a of FIG. 2 a.
FIG. 6 b is an end view of the lock assembly of FIG. 6 a with clockwise rotation of the spindle.
FIG. 6 c is an end view of the lock assembly of FIG. 6 a with counterclockwise rotation of the spindle.
FIG. 7 a is a section view taken along line 7 a - 7 a of FIG. 2 b.
FIG. 7 b is an end view of the lock assembly of FIG. 7 a with clockwise rotation of the spindle.
FIG. 7 c is an end view of the lock assembly of FIG. 7 a with counterclockwise rotation of the spindle.
FIG. 8 a is an exploded view of another selectable lock assembly.
FIG. 8 b is a perspective view of the selectable lock assembly of FIG. 8 a as assembled.
FIG. 9 a is a top view of the selectable lock assembly of FIG. 8 b with the actuator disengaged.
FIG. 9 b is a perspective view of the actuator of the selectable lock assembly of FIG. 9 a.
FIG. 10 a is a top view of the selectable lock assembly of FIG. 8 b with the actuator engaged.
FIG. 10 b is a perspective view of the actuator of the selectable lock assembly of FIG. 10 a.
FIG. 11 a is a perspective view of an alternative actuator with the selectable lock assembly of FIG. 8 a and in the disengaged position.
FIG. 11 b is a partial perspective view of the actuator of FIG. 11 a.
FIG. 12 a is a perspective view of the actuator of FIG. 11 a in the engaged position.
FIG. 12 b is a partial perspective view of the actuator of FIG. 12 a.
FIG. 13 a is an exploded view of another selectable lock assembly.
FIG. 13 b is a perspective view of the selectable lock assembly of FIG. 13 a as assembled.
FIG. 14 is an end view of the lock assembly of FIG. 13 b.
FIG. 15 a is a perspective view of the selectable lock assembly of FIG. 13 b with the engagement rod disengaged.
FIG. 15 b is a section view taken along line 15 b - 15 b of FIG. 15 a.
FIG. 16 a is a perspective view of the selectable lock assembly of FIG. 13 b with the engagement rod engaged.
FIG. 16 b is a section view taken along line 16 b - 16 b of FIG. 16 a.
DETAILED DESCRIPTION
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. And as used herein and in the appended claims, the terms “upper”, “lower”, “top”, “bottom”, “front”, “back”, and other directional terms are not intended to require any particular orientation, but are instead used for purposes of description only.
FIG. 1 illustrates the external portions of a lock assembly 10 mounted within a door 20 . As illustrated, the lock assembly 10 includes a lever 24 housing a key cylinder 28 with a cover 32 to conceal the interface of internal components of the lock assembly 10 with the door 20 . A latch 36 extends through a faceplate 40 mounted in the swing side end of the door 20 adjacent an opposing door frame (not shown).
Referring to FIGS. 2 a and 2 b , an externally accessible selector 100 for adjusting the internal spring torque of a selectable lockset assembly 104 is disposed within a housing 110 . The housing 110 includes a position identifier 114 integrally formed as part of a front face 118 to enable a user to identify whether the lockset is configured for use with a knob (i.e., a knob icon 122 ) or a lever (i.e., a lever icon 126 ). A directional arrow 130 indicates the direction in which to rotate the selector 100 to achieve the desired state. FIG. 2 a shows the selector 100 configured for a knob 134 , while FIG. 2 b shows the selector 100 configured for a lever 138 .
FIGS. 3 a and 3 b illustrate the selectable lock assembly 104 referenced with respect to a proximal end 151 and a distal end 153 . FIG. 3 c illustrates the lock assembly 104 as assembled. Referring to FIGS. 3 a - 3 c , the lock housing 110 defines an aperture 154 having a central axis 158 . The aperture 154 receives a spindle 162 therethrough, which rotates in response to actuation of the handle 134 or the lever 138 (see, e.g., FIGS. 2 a and 2 b ) to move a latch (not shown) from an extended position to a refracted position. The spindle 162 is externally secured through a retainer 166 and a retainer ring 170 that seat against the housing 110 . The spindle 162 receives a lock cylinder (not shown) into a proximal end 174 thereof in a manner known to those of skill in the art. Two elongated members 180 , 182 , connected by arcuate sections 186 , 188 , extend from a distal face 190 of the housing 110 and are together shaped to contain the remaining components of the selectable lock assembly 104 and further provide fixed reference points.
With continued reference to FIGS. 3 a - 3 c , an annular back plate 194 concentric with the axis 158 receives the distal end 198 of the spindle 162 . The back plate 194 includes a housing catch 204 projecting from a proximal face 208 that secures the back plate 194 within the housing 110 to inhibit relative rotation during operation. A slot 212 through the back plate 194 is diametrically spaced from the housing catch 204 and receives an actuator 220 that is operationally engaged by an adjustment member 224 of the selector 100 , as will be subsequently detailed. The slot 212 may be wholly bounded by the back plate 194 or may be disposed circumferentially at the edge of the plate 194 , i.e., as a notch. A projection or stop 230 extending from the distal face 234 of the back plate 194 opposite the housing catch 204 passively interacts with two substantially coplanar biasing members or springs—an upper spring 240 and a lower spring 244 —functionally positioned between the back plate 194 and a retainer member 250 . The biasing springs 240 , 244 as illustrated are linear compression springs, each with a respective first end 260 , 262 and a second end 264 , 266 . The spring constants of the biasing springs 240 , 244 will normally be substantially similar. A pair of opposing protrusions 270 , 272 extending from the proximal face 276 of the retainer member 250 actively interact with the two biasing springs 240 , 244 , as will be further described below. The retainer member 250 includes two generally curvilinear openings 280 , 282 therethrough that mate with conforming slotted extensions 290 , 292 formed at the distal end 198 of the spindle 162 such that the retainer member 250 rotates with the spindle 162 . The spindle 162 , annular back plate 194 , retainer member 250 , members 180 , 182 , and sections 186 , 188 , assembled together, form an arcuate channel within which the biasing springs 240 , 244 can translate and deflect during operation.
Referring to FIG. 4 , a distal end view of the lock assembly 104 is illustrated in a neutral position, in which the handle, either the knob 134 or the lever 138 (not shown), is inactive and therefore does not generate a torque to rotate the spindle 162 . This is further reflected by the substantially horizontally positioned protrusions 270 , 272 of the retainer member 250 . The biasing springs 240 , 244 are consequently both in a relaxed state between the protrusions 270 , 272 and on either side of the stop 230 .
Referring to FIGS. 5 a and 5 b , the adjustment member 224 of the selector 100 is formed from a generally cylindrical shaft 300 , which defines a single thread root 304 . The shaft 300 is operable to rotate adjacent a complementary surface 310 formed in a proximal portion 314 of the actuator 220 . A partial thread crest 320 protrudes from the surface 310 to engage the thread root 304 and transform rotational motion of the adjustment member 224 to linear motion of the actuator 220 in the direction of the central axis 158 . A positioning member 324 of the actuator 220 includes first and second contact surfaces 328 , 332 to interact with the biasing springs 240 , 244 when the selector 100 is actuated, as will be further detailed below. An engagement interface 336 of the adjustment member 224 is operable with a screwdriver or similar tool, though additional configurations for manually rotating the adjustment member 224 are within the knowledge and skill of those in the art. An indicator 340 cooperates with the position identifier 114 of FIGS. 2 a and 2 b and identifies whether the selector 100 is currently configured for a knob or a lever.
FIGS. 6 a - 6 c show a knob configuration. Referring to FIG. 6 a , the locking assembly 104 is shown in a neutral position with no torque applied to the knob 134 . The stop 230 extending from the distal face 234 of the back plate 194 is shown in its fixed position adjacent the first end 262 of the lower biasing spring 244 (and equally adjacent to the second end 264 of the upper biasing spring 240 , not shown). As illustrated, in the knob configuration, the actuator 220 is retracted, i.e., proximally positioned, and does not extend through the slot 212 in the annular back plate 194 .
Referring to FIG. 6 b , in operation, during a clockwise rotation of the spindle 162 (see arrow 350 ) due to rotation of the knob 134 (not shown), the protrusion 272 of the retainer member 250 contacts the first end 260 of the upper biasing spring 240 and compresses the upper biasing spring 240 against the back plate stop 230 . This provides a counter torque to the applied torque of the knob. The lower biasing spring 244 , contacted at end 262 by the protrusion 270 , slides within the housing 110 in a circumferential path defined between the back plate 194 and the retainer member 250 and moves with and between the opposing protrusions 270 , 272 . The lower biasing spring 244 is therefore not compressed and provides no counter torque to the applied torque of the knob. Referring to FIG. 6 c , during a counterclockwise rotation of the spindle 162 (see arrow 354 ), the protrusion 272 contacts the second end 266 of the lower biasing spring 244 and compresses the lower biasing spring 244 against the back plate stop 230 . Due to the relatively equal spring constants between the upper and lower biasing springs 240 , 244 , this motion provides an equal counter torque to the knob as is applied during clockwise rotation of the spindle 162 . The upper biasing spring 240 , contacted at end 264 by the protrusion 270 , slides within the circumferential path described above and moves with and between the opposing protrusions 270 , 272 . The upper biasing spring 240 is therefore not compressed and provides no counter torque to the applied torque of the knob. In FIGS. 6 b - 6 c , neither one of the first or second contact surfaces 328 , 332 of the positioning member 324 interferes with the motion of the biasing springs 240 , 244 .
FIGS. 7 a - 7 c show a lever configuration. Referring to FIG. 7 a , the locking assembly 104 is shown in a neutral position with no torque applied to the lever 138 . In this configuration, the positioning member 324 of the actuator 220 extends through the slot 212 of the back plate 194 . The stop 230 is again fixed in place.
Referring to FIG. 7 b , in operation, during a clockwise rotation of the spindle 162 (see arrow 362 ) due to rotation of the lever 138 (not shown), the protrusion 272 contacts the first end 260 of the spring 240 and compresses the spring 240 against the back plate stop 230 , as in FIG. 6 b , to provide a counter torque to the applied torque of the lever. Since the positioning member 324 is now fixed in place with the second contact surface 332 adjacent the second end 266 of the lower spring 244 , the protrusion 270 contacts the first end 262 of the lower spring 244 and compresses the lower spring 244 against the second contact surface 332 . Thus, both the upper biasing spring 240 and the lower biasing spring 244 are concurrently compressed, effectively adding their spring constants together in a mechanically parallel spring relationship to counter the torque applied at the lever. Referring to FIG. 7 c , during a counterclockwise rotation of the spindle 162 (see arrow 366 ), the protrusion 272 contacts the second end 266 of the lower spring 244 and compresses it against the stop 230 , as in FIG. 6 c . With the first contact surface 328 adjacent the first end 260 of the upper spring 240 , the protrusion 270 contacts the second end 264 of the upper spring 240 and compresses the upper spring 240 against the first contact surface 328 . The springs 240 , 244 are again concurrently compressed in a mechanically parallel spring relationship to counter the torque applied by the lever. Thus, the lever arrangement receives about twice the restoring force as the knob arrangement.
FIG. 8 a illustrates another selectable lock assembly 400 , unassembled and referenced with respect to a proximal end 401 and a distal end 403 . FIG. 8 b illustrates the lock assembly 400 as assembled. Referring to FIGS. 8 a - 8 b , the selectable lock assembly 400 includes a lock housing 410 defining an aperture 414 with a central axis 418 through which a spindle 422 rotates in response to actuation of a handle or a lever (not shown) to move a latch (not shown) from an extended position to a refracted position. The spindle 422 receives a lock cylinder (not shown) and is externally secured through a retainer 424 and a retainer ring 428 that seat against the housing 410 .
With continued reference to FIGS. 8 a and 8 b , a spring holder 432 fixedly disposed within the housing 410 provides an arcuate track 436 for a first biasing spring 440 . In the present construction, the first biasing member or spring 440 is a linear compression spring with first and second ends 460 , 462 . Lips 444 , 448 at each end of the spring holder 432 constrain the motion of the first biasing spring 440 to deflection within the track 436 . A second biasing member or spring 450 is functionally disposed adjacent a retainer member, or spring cage 454 . The second biasing spring 450 is a torsion spring with first and second ends or legs 466 , 468 positioned to engage an actuator 470 secured to the housing 410 with a clip 472 . The spring cage 454 includes two generally curvilinear openings 474 , 476 therethrough that mate with conforming slotted extensions 480 , 482 formed at the distal end of the spindle 422 . The spring cage 454 therefore rotates with rotation of the spindle 422 . Extending proximally from the spring cage 454 are first and second protrusions 490 , 492 that interact with the first biasing spring 440 . Specifically, the first and second protrusions 490 , 492 include lateral edges 494 , 496 shaped to abut the first and second ends 460 , 462 , respectively, of the first biasing spring 440 . An arm 500 also extending in the proximal direction from the spring cage 454 includes opposing grooves 502 , 504 configured to catch the first and second ends 466 , 468 of the second biasing spring 450 . The linear spring constant of the first biasing spring 440 and the torsion spring constant of the second biasing spring 450 may or may not be functionally equivalent, i.e., the combined spring rate for a lever installation can vary depending on the desired ratio between knob and lever installations.
The actuator 470 is generally cylindrical in form and includes an engagement interface 520 operable with a screwdriver or similar tool. An identifier 524 describes the current state of the actuator (knob or lever) in the same manner as described for FIGS. 2 a and 2 b . A semicircular shaft 514 extends eccentrically from the distal face 510 of the actuator 470 .
Referring to FIGS. 9 a and 9 b , the locking assembly 400 is shown in a neutral position with no torque applied to the spindle 422 . With the actuator 470 positioned for a knob handle, the first and second ends 466 , 468 of the second biasing spring 450 are clear of the shaft 514 , i.e., the shaft 514 is not in engagement with either of the first or second ends 466 , 468 of the torsion spring 450 . In operation, during clockwise rotation of the spindle 422 , which rotates the spring cage 454 , the first biasing spring 440 is deflected against the lip 448 (not shown) of the spring holder 432 by the interaction of the first lateral edge 494 of the protrusion 490 of the spring cage 454 against the end 460 of the first biasing spring 440 . The torsion spring 450 is free to rotate with the spring cage 422 via arm 500 unhindered by the shaft 514 of the actuator 470 . During counterclockwise rotation of the spindle 422 , which also rotates the spring cage 454 , the first biasing spring 440 is deflected against the lip 444 of the spring holder 432 by the interaction of the second lateral edge 496 of the protrusion 492 (not shown) of the spring cage 454 against the end 462 of the first biasing spring 440 . The only counter torque applied to the spindle 422 in either case is therefore by virtue of deflection of the first biasing spring 440 .
FIGS. 10 a and 10 b also show the locking assembly 400 in a neutral position. Turning the actuator 470 to ‘lever’ from ‘knob’ rotates and repositions the shaft 514 between the first and second ends 466 , 468 of the second biasing spring 450 . In operation, during clockwise or counterclockwise rotation of the spindle 422 , the first biasing spring 440 is deflected by the spring cage 454 as previously described, but the second biasing spring 450 is no longer free to rotate with the spring cage 454 . During clockwise rotation, the end 468 of the second biasing spring 450 is operably fixed against the shaft 514 while force is applied to the end 466 by the groove 502 of the arm 500 . During counterclockwise rotation of the spindle 422 , the end 466 of the second biasing spring 450 is operably fixed against the shaft 514 while force is applied to the end 468 by the groove 504 . Separation of the ends 466 , 468 through rotation, which deflects the spring 450 , applies torque to the spindle 422 in excess of that supplied by the first biasing spring 440 alone.
Referring to FIGS. 11 a and 11 b , an alternative actuator 540 is shown disposed within the housing 410 . The actuator 540 includes an accessible slide switch 544 with two positions. In FIG. 11 a , the slide switch 544 is selected for a knob handle. As shown in FIG. 11 b , the first and second ends 466 , 468 of the second biasing spring 450 are clear of the blocking bar 550 of the actuator 540 and the second biasing spring 450 is free to rotate with the spindle 422 in the same manner previously described. In FIG. 12 a , the slide switch 544 is selected for a lever handle and as shown in FIG. 12 b , the blocking bar 550 , through radially inward movement, is functionally disposed between the first and second ends 466 , 468 of the second biasing spring 450 , activating the second biasing spring 450 as previously described.
FIG. 13 a illustrates another selectable lock assembly 600 , unassembled and referenced with respect to a proximal end 601 and a distal end 603 . FIG. 13 b illustrates the lock assembly 600 as assembled. Referring to FIGS. 13 a and 13 b , a housing 610 includes an aperture 614 defining a central axis 618 that receives a spindle 622 . The spindle 622 rotates with the actuation of a handle or a lever (not shown) to move a latch (not shown) from an extended position to a retracted position. A spring plate 630 is rotatably fixed to the spindle 622 and includes a distally extending slotted wall 634 with upper and lower slots 638 , 642 . A lever biasing member or spring 650 with a right-hand winding has an upper leg 654 and a lower leg 656 and is situated such that the upper leg 654 extends upward through the upper slot 638 of the spring plate 630 and the lower leg 656 extends downward distally of the slotted wall 634 . A knob biasing member or spring 670 with a left-hand winding and larger mean diameter than the lever spring 650 is concentrically nested over the lever spring 650 and has an upper leg 674 and a lower leg 676 . The upper leg 674 extends upward distally of the slotted wall 634 and abuts the edge 680 of a groove 682 formed in the wall 634 , best seen in FIGS. 15 a and 16 a . The lower leg 676 extends downward through the lower slot 642 of the spring plate 634 and abuts an edge 684 formed in the spring plate 630 . As illustrated, the lever spring 650 and the knob spring 670 are torsion springs. Alternative nested designs of the lever spring 650 and the knob spring 670 can be achieved by varying the coil winding direction, mean spring diameter, and spring leg orientation of each spring.
With continued reference to FIGS. 13 a and 13 b , a lever spring plate 690 sits within the knob spring plate 630 enclosed by the slotted wall 634 and includes a pair of opposed distally extending arcuate arms 694 , 696 positioned radially between the slotted wall 634 and the lever spring 670 . The lever spring plate 690 is selectively engaged and activated to rotate with the spindle 622 by actuation of an engagement rod or actuator 700 through a plate orifice 704 , as further described below.
Referring to FIG. 14 , an end view of the lock assembly 600 shows that the upper and lower legs 674 , 676 of the knob spring 670 and the upper and lower legs 654 , 656 of the lever spring 650 are held against rotation in one direction by diametrically opposed bosses 710 integrally formed as part of the lock housing 610 . As illustrated, the upper legs 674 , 654 are blocked from counterclockwise rotation and the lower legs 656 , 676 are blocked from clockwise rotation.
Referring to FIGS. 15 a and 15 b , the locking assembly 600 is shown in a neutral position with no external torque applied. In the knob configuration, the actuator 700 is retracted and does not extend through the orifice 704 in the lever spring plate 690 . In operation, upon clockwise or counterclockwise rotation of the spindle 622 , the knob spring 670 is deflected by interaction with the edges 680 , 684 in the knob spring plate 690 . Specifically, with clockwise rotation of the spindle 622 (viewed from the end), the edge 680 contacts and rotates the upper end 674 of the knob spring 670 against the operably fixed lower end 676 , and the upper slot 638 passes over and does not interact with the upper leg 654 of the lever spring 650 . With counterclockwise rotation of the spindle 622 , the edge 684 formed in the slotted wall 634 contacts and rotates the lower leg 676 of the knob spring 670 against the operably fixed upper leg 674 . Thus, counter torque to the actuation of the knob is provided by the knob spring 670 only. The lever spring plate 690 does not rotate with the spindle 622 until it is selectively engaged by the actuator 700 .
Referring to FIGS. 16 a and 16 b , in the neutral position of the lever configuration, the actuator 700 is pushed into the lever spring plate orifice 704 to engage the lever spring plate 690 . In operation, this causes the lever spring plate 690 to rotate with the spindle 622 and the knob spring plate 630 . The interaction of the knob spring plate 630 and the knob spring 670 remains as previously described. With clockwise rotation of the spindle 622 , the upper arcuate arm 694 of the lever spring plate 690 contacts and rotates the upper leg 654 of the lever spring 650 to deflect it against the operably fixed lower leg 656 of the lever spring 650 . With counterclockwise rotation of the spindle 622 , the lower arcuate arm 696 contacts and rotates the lower leg 656 of the lever spring 650 against the operably fixed upper leg 654 . Due to the geometry of the lever spring plate 690 , the upper and lower arcuate arms 694 , 696 also contact and rotate the upper and lower legs 674 , 676 of the knob spring 670 in conjunction with the knob spring plate 630 as described in FIGS. 15 a - 15 b . The counter torque to the actuation of the lever is thus provided by the combination of the knob spring 670 and the lever spring 650 .
To switch from a knob trim to a lever trim, the user first removes the existing trim, manually alternates the selector 100 or actuator 470 (with, for example, a screwdriver) or slides the actuator 540 or 700 to the proper trim mode, and installs a new trim. Disassembly of the lock assembly 104 , 400 , 600 is not required.
The single lock assembly 104 , 400 , 600 as described provides more than one spring rate to accommodate different trim configurations. This benefits manufacturers by reducing the number of parts necessary to be manufactured, stored and tracked, and benefits consumers by offering an easy opportunity to upgrade from knobs to levers without the need to purchase a new lock chassis assembly.
Various features and advantages of the invention are set forth in the following claims.
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A latch assembly configured to attach to a door includes one of a knob and a lever. The latch assembly further includes a latch extending from the door. A spindle is rotatable from a first position to a second position to move the latch from an extended position to a retracted position. A first biasing member is selectively operable to bias the spindle toward the first position. A second biasing member is selectively operable to bias the spindle toward the first position. An actuator is movable between a knob position in which only one of the first biasing member and the second biasing member biases the spindle toward the first position and a lever position in which both the first biasing member and the second biasing member cooperate to bias the spindle toward the first position.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a division of U.S. application Ser. No. 09/840,552, filed Apr. 23, 2001 which was a continuation of copending International Application PCT/EP99/07997, filed Oct. 21, 1999, which designated the United States.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a device for cleaning a product which has a substrate chamber in which there is a substrate guide and which has a substrate holder.
[0004] U.S. Pat. No. 5,238,752 describes a thermal barrier coating system with an intermetallic bond coat. The thermal barrier coating system is applied to a metallic base body, in particular to a Cr—Co-steel for an aircraft engine blade. An intermetallic bond coat, in particular of nickel aluminide or a platinum aluminide, is applied directly to this metallic base body. This bond coat is adjoined by a thin ceramic layer of aluminum oxide, to which the actual thermal barrier coating, in particular of yttrium stabilized zirconium oxide, is applied. This ceramic thermal barrier coating of zirconium oxide has a rod-like structure, the rod-like columns being oriented substantially perpendicular to the surface of the base body. The intention of this is to improve the ability to withstand cyclic thermal loads. The thermal barrier coating is deposited on the base body by means of an electron beam PVD (Physical Vapor Deposition) process, zirconium oxide being vaporized from a metal oxide body by an electron beam gun. The process is carried out in a corresponding device, in which the base body is preheated to a temperature of approximately 950° C. to 1000° C. During the coating operation, the base body is rotated at a constant rate in the jet comprising the metal oxide.
[0005] An electron beam PVD process for producing a ceramic coating is also described in U.S. Pat. No. 5,087,477. The ceramic coating produced in this case has a layer thickness of between 250 and 375 μm.
[0006] To provide good adhesion between the coating and the base body, it is advantageous for the base body to be cleaned prior to the coating operation. It has become known from British patent specifications GB 2 323 855 and GB 1 447 754 to clean a product which is to be coated prior to the coating. The cleaning in those cases takes place by means of a sputtering process, in which firstly a plasma is generated and the positive ions of the plasma are accelerated toward the base body. The device for cleaning the base body is integrated in the device for coating the base body. In order for the base body to be heated to a suitable coating temperature, the base body is heated with the aid of an electron beam. There is provision for it to be possible to switch between the heating phase by means of the electron beam and the cleaning phase by means of ion sputtering. To do this, it is necessary for the relationship of potential between the base body and the electron source or the positive ions of the plasma to be adjusted or controlled. To do this, GB 2 323 855 provides for the base body to be connected to a voltage source, in order to set the base body to a suitable potential. In GB 1 447 754, a voltage source and a monitoring device are also provided, in order to be able to influence the relationships of potential between base body, electron source and plasma. Therefore, to set a suitable relationship of potential, according to both literature sources an active voltage supply is required.
SUMMARY OF THE INVENTION
[0007] The object of the present invention is to provide a device for cleaning an article.
[0008] With the above and other objects in view there is provided, in accordance with the invention, a method of cleaning a surface of an article having a metallic base body, the method which comprises:
[0009] generating a plasma with electrically positively charged ions, accelerating the ions towards the article, and bringing ions into contact with the base body for cleaning the base body;
[0010] directing an electron beam onto the base body; and
[0011] controlling an outgoing flow of electrons coming into contact with the base body by connecting the base body to a reference potential via a switch at a given frequency, which may be fixed preset, adjustable, or regulated.
[0012] In other words, the object relating to a process for cleaning the surface of a product which has a metallic base body is achieved by the fact that a plasma with electrically positively charged ions is generated and the ions are accelerated toward the product, so that they come into contact with the base body for cleaning purposes, an electron beam being directed onto the base body, and that the outgoing flux of electrons which come into contact with the base body is controlled as a result of the base body being connected to a reference potential via the switch with a fixedly preset, adjustable or regulated frequency.
[0013] With this process, the surface of the product, in particular a component in a plasma, undergoes preliminary cleaning in such a manner that the adhesion of layers which are to be vapor-deposited is significantly improved compared to a process involving thermal cleaning. The latter may, for example, lead to gases escaping.
[0014] Compared to the processes which are known from the prior art, the process described here has the crucial advantage of being significantly simpler and therefore also less susceptible to faults.
[0015] This is primarily due to the fact that the connection of the base body to the reference potential which is, for example, frame potential or ground potential, can be switched on and off makes it easy to suitably adjust the relationship of potential between base body and plasma and the electrons of the electron beam. Therefore, the electrical potential of the base body is controlled by means of the connection to the reference potential. The outgoing flux can in this case be controlled between a maximum value and a minimum value, the minimum value preferably being zero, i.e. there is no outgoing flux of electrons. In the latter case, the electrons do not flow out and an electron build-up is produced around the product, which negatively charges the product. In the presence of the plasma, the positively charged ions are accelerated toward the product; they come into contact with the product at a parameter-dependent velocity. Contaminants present on the surface of the product are removed by means of a pulse exchange with this surface.
[0016] On the other hand, if the outgoing flux is set to a maximum value, i.e. the switch is closed and the base body is connected to the reference potential, for example, frame potential, the electrons can flow out of the electron beam without obstacle. Consequently the positive ions of the plasma are not accelerated toward the base body. Therefore, when the switch is closed, the product is substantially only exposed to the electron beam, which heats the product. Therefore, by actuating the switch it is simple to switch over between a cleaning phase and a heating phase. The switch can be suitably actuated with a fixedly preset, adjustable or regulated frequency.
[0017] The outgoing flux of electrons preferably takes place via an electrical outgoing line, which is alternately opened and closed by means of the switch. This outgoing line produces a current path which is constantly switched between passing and blocking. The alternating switching between passing and blocking of the current path can take place at a constant, possibly temporally variable frequency. Alternating switching allows alternating charging and discharging of the product, as a result of which, in the presence of a gas, an alternating voltage discharge (plasma) can be ignited or maintained. In this way, it is possible to continuously clean the component.
[0018] The frequency at which the outgoing flux of electrons is controlled may in this case lie between a few hertz and frequencies up to the megahertz range, in particular, the frequency may be approximately 50 kHz or approximately 27 MHz. The high-frequency switching has the crucial advantage that, at suitable high frequencies, the cleaning effect is not dependent upon the component geometry. Therefore, the high-frequency switching allows reliable and in particular homogenous cleaning of the product.
[0019] There is a potential difference, i.e. an electric voltage, between the plasma and the base body, which potential difference can be influenced, in particular, set, by suitably controlling the outgoing flux of electrons from the base body. This potential difference produces a bias voltage in a range from approximately 100 V to approximately 1000 V. This bias voltage may be selected in such a way that the formation of the plasma, in particular as a result of an alternating voltage discharge, can be ignited and maintained.
[0020] Preferably the bias voltage between the electrically positively charged ions of the plasma and the base body is determined and, if appropriate, can be used to control the outgoing flux of the electrons. It is thus also possible to carry out a regulating process between bias voltage and outgoing flux of the electrons with the view to achieving the most expedient cleaning of the product possible depending on the type of metallic base body (geometric shape, metallurgical composition, etc.). The bias voltage is in this case measured and displayed as a temporal mean.
[0021] In accordance with an added feature of the invention, the plasma is generated by an electron beam, in particular by the electron beam which is directed onto the base body and can also be used, inter alia, to heat the product. The electron beam may in this case be of fan-shaped or cone-shaped design as an electron beam fan or cone, in order to be able to irradiate a large area of the base body and to be able to generate a sufficiently large volume of plasma. It is also possible for the plasma to be generated in a separate process and for the plasma which has already been ionized to be passed into the vicinity of the product. The gas from which the plasma is formed is preferably an inert gas, in particular a noble gas, such as argon. This ensures that no undesirable chemical reactions take place on the surface of the product, in particular the base body, but rather the product is simply cleaned. As an alternative, it is also possible to use a reactive gas, in particular hydrogen, to form the plasma.
[0022] When using hydrogen, the plasma is also able to remove oxide on the product by means of oxidation to form water.
[0023] The product is preferably rotated about an axis of rotation during the cleaning in which positively charged ions come into contact with the product. The result is uniform cleaning and heating of the product even in the event of complex geometries.
[0024] To enable the cleaning to be carried out as quickly and effectively as possible, in a particularly advantageous embodiment, the product is heated before the cleaning operation. The heating causes a large proportion of the contaminants on the surface and in the product to vaporize or gasify. The gasification of contaminants situated in the body of the product is in this context particularly advantageous with a view to the properties of the component. As a result, the cleaning phase by means of ion firing (sputtering) which follows this thermal cleaning phase becomes more effective. Therefore, preheating of the product prior to the sputtering is of considerable significance primarily from an economic viewpoint, not least because of the time saved. This embodiment with preheating is not restricted to the configuration with an outgoing flux of electrons passing via a switch to the reference potential, for example frame potential. Rather, it is independent of the particular way in which the potential level of the product is set.
[0025] During the cleaning, the product is preferably simultaneously heated to a temperature which is greater than or equal to the coating temperature, which in particular lies above 800° C. Heating to a temperature above the coating temperature has the beneficial effect that there is relatively little evolution of gases during the subsequent coating at a lower temperature. This heating can be achieved by means of the electron beam, which simultaneously serves to generate a controllable negative potential of the base body.
[0026] The process for cleaning and, if appropriate, simultaneously heating the product is preferably integrated in a process for coating the product with a protective layer, in particular a thermal barrier coating. According to the invention, the second object, relating to a process for coating a product, is therefore achieved by the fact that the product undergoes prior cleaning by a plasma, in the manner described above, prior to the actual coating process.
[0027] The process for producing a thermal barrier coating is preferably carried out as an electron beam physical vapor deposition (EB-PVD) process or as a reactive gas flow sputtering process as described, for example, in international PCT publication WO 98/13531 A1.
[0028] Within the context of the overall coating process, the product has preferably already been preheated prior to the cleaning, to a temperature which in particular is higher than the actual coating temperature of the product, which is over 800° C. As has already been stated, this increases the effectiveness of the cleaning by means of ion sputtering. The heating takes place, for example, with the aid of the electron beam and/or a further heating device. After the cleaning, the product is heated to the coating temperature; this is also to be understood as meaning that heating to the coating temperature has already taken place during the cleaning, so that after the cleaning the product is at the coating temperature. Preferably, preheating, cleaning and coating immediately follow one another, in which case the preheating already produces an initial cleaning action and in which case during the actual cleaning it is possible to switch between sputtering mode and heating phase (by means of electron firing). The fact that the three processes of preheating, cleaning and coating immediately follow one another ensures that the product is always held at a sufficiently high temperature level.
[0029] In accordance with an additional feature of the invention, the actual cleaning process is carried out in a chamber, referred to below as the substrate chamber. This may be a preheating chamber of a coating installation, the actual coating chamber itself, or a separate chamber which is designed specifically for the cleaning. To generate the electron beam which is used to electrically charge the base body, it is possible to use an electron beam gun, which is likewise used to carry out the coating process or is accordingly designed only for cleaning or heating. An electron beam gun of this type may have an electron beam capacity of up to 150 kW with an acceleration voltage of up to 35 kV.
[0030] With the above and other objects in view there is also provided, in accordance with the invention, a device for cleaning an article, comprising:
[0031] a housing defining a substrate chamber;
[0032] a substrate guide disposed in said substrate chamber;
[0033] a substrate holder for holding an article connected to said substrate guide in a mechanically fixed and electrically insulated manner;
[0034] an electrical outgoing line connected to said substrate holder, and a switch connected in said electrical outgoing line for selectively connecting said substrate holder to a reference potential; and
[0035] an electron beam gun for generating an electron beam directed onto the article.
[0036] In other words, the object relating to a device for cleaning a product, in particular a component of a gas turbine, is achieved by a device which has a substrate chamber in which a substrate guide with a substrate holder for holding the product is provided, the substrate guide being connected in a mechanically fixed but electrically insulated manner to the substrate holder, and it being possible to connect the substrate holder to reference potential via an outgoing line and by means of a switch arranged in the outgoing line. The reference potential may in this case, for example, be frame potential or ground potential.
[0037] In accordance with another feature of the invention, the switch is connected to a control device for controlling the alternating opening and closing of the switch. This makes it possible to actuate the switch with a fixedly preset, adjustable or regulated frequency. The substrate chamber may in this case be the actual coating chamber of a coating installation, a preheating chamber of a coating installation or a separate chamber.
[0038] The outgoing line is preferably connected to a current- and/or voltage-measuring device, so that the electron current passing through the outgoing line and a bias voltage between the base body and a plasma which is present in the substrate chamber can be measured. The plasma itself is preferably generated by firing an electron beam from a electron beam gun onto the base body. The electron beam gun may in this case be arranged inside the substrate chamber or outside this chamber and may be specifically designed for firing the base body, for example for heating purposes. It is also possible to use an electron beam gun which is used to fire at a coating target in order to produce a coating on the base body. The current- and/or voltage-measuring device is preferably connected to the control device.
[0039] Furthermore, to regulate the switching frequency of the switch, it is preferable to provide a regulator for which a desired value is preset. A desired frequency value for the regulator may in this case be established, for example, by means of a desired current value and/or a desired voltage value.
[0040] Preferably, the substrate chamber is a coating chamber of a coating installation and the substrate holder and the substrate guide, after cleaning of the product, also simultaneously serve to hold the product during the coating with a protective layer, in particular a thermal barrier coating. During the cleaning, the product is held in the substrate holder, which is electrically insulated with respect to the substrate guide, which serves as the anode. Together with the outgoing line, the substrate holder forms a current path which is controllable, i.e. switchable. The substrate holder is therefore likewise brought to the same potential as the substrate guide, preferably to ground potential (earth). The parameters such as bias voltage, velocity of the positive plasma ions, etc. can be set, by means of the frequency of the switchable current path which is formed via the electrical outgoing line, in such a way that a particularly good cleaning action is produced according to the particular product used.
[0041] The product is preferably a component of a thermal machine, in particular of a gas turbine, such as a stationary gas turbine used in the power plant sector or a component of an aircraft engine turbine. The product may in this case be designed as a heat shield of a combustion chamber or as a turbine blade, a turbine rotor blade or a turbine guide vane.
[0042] In accordance with a further feature of the invention, the protective layer, in particular the thermal barrier coating, is a ceramic layer. It may include zirconium oxide (ZrO 2 ) or another ceramic material which is suitable for use at high temperatures, in particular a metal oxide. A zirconium oxide is preferably partially or completely stabilized with yttrium oxide (Y 2 O 3 ) or another oxide of a rare earth element.
[0043] In accordance with yet a further feature of the invention, the base body is a metallic substrate. Nickel-base and/or cobalt-base alloys such as those which are described, for example, in U.S. Pat. No. 4,405,659, inter alia, are particularly suitable for applications at high temperatures with corresponding demands imposed on resistance to corrosion.
[0044] An adhesion promoter layer is arranged between base body and thermal barrier coating. This adhesion promoter layer may consist of an alloy of iron, cobalt and/or nickel with chromium, aluminum, yttrium. Instead of, or in addition to yttrium, one of the elements from group IIIb of the periodic system, including the actinides and the lanthanides and, in addition, or as an alternative, rhenium may be included. Yttrium-containing alloys of this type are described in the literature under the designation “MCrAlY” alloy. Alloys which contain significantly more rhenium than yttrium may be referred to as “MCrAlRe” alloys. An oxide layer, in particular a layer of aluminum oxide, chromium oxide and/or gallium oxide, may be provided between the adhesion promoter layer and the thermal barrier coating. An oxide layer of this type may already have been applied as an oxide or may form over the course of time as a result of subsequent oxidation (thermally grown oxide, TGO).
[0045] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0046] Although the invention is illustrated and described herein as embodied in a device for cleaning an article, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0047] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] [0048]FIG. 1 is a perspective view of a turbine rotor blade;
[0049] [0049]FIG. 2 is a cross section through a turbine blade;
[0050] [0050]FIG. 3 is a partial sectional view of a thermal barrier coating system of the turbine blade of FIG. 2; and
[0051] [0051]FIG. 4 is a diagrammatic section through a coating installation for coating a turbine blade with thermal barrier coating.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is seen, as a representative of the article of manufacture 1 , a rotor blade of a turbine, in particular of a gas turbine. The rotor blade 1 , which is made from iron, cobalt and/or nickel, has a blade root 14 , by means of which it can be secured in a non-illustrated rotatable turbine shaft. The blade root 14 is adjoined by the actual blade root region, which extends from a leading edge 7 to a trailing edge 8 via a pressure side 9 on one side, and a suction side 10 on the other side. Cooling channels 13 for carrying a cooling medium, in particular cooling air, are provided in the actual blade region. The blade region has a surface 4 with differently curved surface regions.
[0053] [0053]FIG. 2 illustrates a cross section through a gas-turbine blade —again representing the article of manufacture—around which a hot gas flows 16 during its use in a gas turbine. In cross section, the turbine blade 1 extends from a leading edge 7 , via a pressure side 9 and a suction side 10 , to a trailing edge 8 . The turbine blade 1 is formed from a substrate or base body 2 , in the interior of which a plurality of cooling channels 13 for carrying cooling air are provided. The entire surface 4 of the turbine blade 1 is coated with a thermal barrier coating 5 .
[0054] [0054]FIG. 3 diagrammatically depicts the structure of a thermal barrier coating system 15 . The thermal barrier coating system 15 is applied to the base body 2 . Directly adjacent to the base body 2 , it has an adhesion promoter layer 11 , which is adjoined by an oxide layer 12 and the actual thermal barrier coating 5 , which is on top of the oxide layer 12 . The adhesion promoter layer 11 may be a known alloy of the type MCrAlY or MCrAlRe. The oxide layer 12 may substantially comprise an aluminum oxide or may alternatively or additionally include metal oxides, such as chromium oxide or gallium oxide. The choice of adhesion promoter layer 11 and of oxide layer 12 naturally depends on the material of the base body 2 and on the thermal barrier coating 5 to be applied. The latter may, for example, consist of partially stabilized zirconium oxide. The thermal barrier coating 5 has a fine structure with ceramic columns 6 which are oriented substantially perpendicular to the surface 4 of the base body 2 . The ceramic columns 6 each have a mean column diameter D which, for a layer thickness of the thermal barrier coating 5 of approximately 100 μm to 200 μm, lies in the range between 0.5 and 5 μm, preferably below 2.5 μm.
[0055] [0055]FIG. 4 shows a diagrammatic longitudinal section through a device 20 for cleaning a article 1 , which is integrated in a coating device for applying a thermal barrier coating 5 to the article 1 , in particular to a gas turbine blade. The device 20 has a substrate chamber 24 , which serves as a coating chamber. A suitable sub-atmospheric pressure (vacuum) can be established in the chamber 24 , and a gas, in particular an inert gas, is introduced. Pumps, which are not shown and to which the substrate chamber 24 is connected via a pump outlet 36 , are provided for the purpose of evacuating the chamber 24 and to build the vacuum in the chamber 24 . A substrate guide 26 , which extends along an axis of rotation 32 and is designed, for example, as a hollow cylindrical tube, is introduced into the substrate chamber 24 via an introduction chamber 38 . The substrate guide 26 is adjoined by a substrate holder 22 which is mechanically fixedly connected to the substrate guide. The article 1 is held rotatably, and optionally also pivotably, in the substrate holder 22 . The substrate guide 26 is electrically insulated from the substrate holder 22 by insulation 27 . The substrate guide 26 is grounded outside the substrate chamber 24 .
[0056] The substrate holder 22 is connected to an electrical outgoing line 28 which, for example, is guided through the substrate guide 26 . A measuring device 31 A, 31 B, in particular a current-measuring device 31 A for measuring an electric current I and a voltage-measuring device 31 B for measuring an electrical bias voltage U, is arranged in the electrical outgoing line 28 . Furthermore, a switch 29 , which can be controlled by a control device 30 , is provided in the outgoing line 28 . The switch 29 may be designed as a mechanical or electronic switch or as a suitable control mechanism. Its essential function is that of controlling the electric current I flowing through the outgoing line 28 . The outgoing line 28 is also connected, outside the substrate chamber 24 , to a reference potential, which may be frame or ground. The switch 29 and the measuring devices 31 A, 31 B are connected to a control device 30 , by means of which the switch 29 can be controlled, so that the switch 29 opens and closes at a frequency which can be preset by means of the control device 30 . The frequency or on/off duration (duty factor) used for the opening and closing may be effected as a function of the bias voltage U determined by means of the measuring device 31 A, 31 B. The frequency may also be fixed by means of a desired current value I* and/or a desired voltage value U*, the desired current value I* and/or the desired voltage value U* being input into the control device 30 and being compared to the actual values U, I in the control device 30 . The control signals for the switch 29 are passed from the control device 30 to the switch 29 .
[0057] An electron beam gun 18 , which generates an electron beam 19 , is provided on the substrate chamber 24 , above the substrate holder 22 . The electron beam 19 may, in this case, as shown, be of fan-shaped or cone-shaped design as an electron beam fan or electron beam cone. Using the grounding of the substrate guide 26 and the controllable grounding (reference potential) of the substrate holder 22 , the electron beam 19 is guided toward the article 1 . On the way to the article 1 , the electron beam 19 causes the gas situated in the substrate chamber 24 , for example, an inert gas such as argon, to be ionized. As a result, a plasma 21 is formed in the vicinity of the article 1 . The electrons which come into contact with the article 1 from the electron beam 19 are discharged via the outgoing line 28 when the switch 29 is closed.
[0058] When the switch 29 is open, there is a build-up of electrons in front of the article 1 , i.e. a negatively charged cloud of electrons around the article 1 , with the result that the positively charged ions of the plasma 21 are accelerated toward the article 1 . The positive ions which have been accelerated in this way come into contact with the article 1 and thus cause contaminants on the article 1 to be removed.
[0059] The constant change between an open and closed state of the switch 29 therefore leads to a frequency-dependent alternating charging and discharging of the article 1 , so that an alternating voltage discharge (plasma formation) is ignited or maintained. This allows continuous cleaning of the article 1 , and surface activation prior to a coating operation. High frequency switching is preferably established via the switch 29 and the control device 30 in such a manner that a cleaning action which is independent of the geometry of the article 1 is achieved. This leads to particularly effective and homogeneous surface cleaning.
[0060] A coating target 23 , for example made from zirconium or zirconium oxide, is arranged in the substrate chamber 24 , which at the same time represents the coating chamber of a coating installation, at a lower level than the article 1 . A further electron beam gun 25 for generating a further electron beam 35 is provided in the substrate chamber 24 . To carry out the actual coating of the article 1 , the substrate chamber 24 has a feed 33 for an oxygen-containing gas 34 , so that additional oxidation for a metal-ceramic thermal barrier coating can be achieved. The article 1 is, for example, a gas turbine blade or a heat shield element with a protective layer, in particular with a thermal barrier coating made from a ceramic. The coating target 23 is grounded during the actual coating operation. The electron beam 35 is diverted toward the coating target 23 (as shown in dashed lines), and then comes into contact with the coating target 23 , where it causes the material of the coating target 23 , in particular zirconium or zirconium oxide, to be vaporized. The material which has been vaporized in this way flows toward the article 1 , where it is deposited, if appropriate with simultaneous oxidation, as a protective layer (thermal barrier coating). The article 1 is in the process rotated about the axis of rotation 32 as a result of the entire substrate guide 26 being rotated about the axis of rotation 32 by means of a non-illustrated motor. The rotation of the article 1 about the axis of rotation 32 is also effected during the cleaning operation by means of plasma ions. The plasma discharge and therefore the ion firing of the substrate 1 can also be maintained during the coating, so that interim cleaning is achieved.
[0061] In the example illustrated, the entire coating process can be carried out in the substrate chamber 24 . Preferably, in a first process step, the article 1 is heated, without the presence of a gas which forms a plasma 21 , by means of an electron beam 19 to a temperature which lies above the actual coating temperature. This advantageously leads to prior thermal cleaning on account of the vaporization/gasification of contaminants. In a second process step, in which gas which forms the plasma 21 is now present, renewed firing using the electron beam 19 takes place, with the result that simultaneous cleaning of the article 1 by means of the plasma 21 and heating of the article 1 by means of the electron beam 19 are achieved. On account of the prior thermal cleaning, this final cleaning by means of ion firing (sputtering) can be carried out significantly more quickly and more effectively. After the cleaning of the article 1 has ended, this product has been heated to the coating temperature, and electrons are fired on to the coating target 23 , with the result that the protective layer 5 , in particular a thermal barrier coating, is applied to the article 1 . The cleaning of the article 1 by means of the plasma 21 renders the adhesion of the thermal barrier coating to the article 1 particularly superior.
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The surface of an article with a metallic base body is cleaned. A plasma comprising electrically positively charged ions is generated, and the ions are accelerated toward the article, so that they come into contact with the base body for cleaning purposes. To do this, an electron beam is directed onto the base body. The outgoing flux of electrons which come into contact with the base body is controlled by the base body being connected to a reference potential via a switch of at a fixed, adjustable or regulated frequency.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of German patent application 10354608.1, filed Nov. 21, 2003, herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an effect yarn which is formed from an alternating line-up of webs and effects consisting of predetermined thickenings and to a method for producing such an effect yarn on an open-end rotor spinning machine, wherein the effect yarn is reconnected by means of a piecer after yarn interruptions.
[0003] During the production of yarn, as high a uniformity of the yarn as possible is generally aimed for within narrow tolerances. In contrast, for effect yarns, the non-uniformity of the yarn is characteristic. A yarn in which thick locations with predetermined larger diameters and with predetermined lengths, the so-called effects, are present is designated an effect yarn. The yarn sections located in between with a smaller diameter are designated webs. A specific, constantly recurring, intrinsically closed sequence of effects and webs in an alternating series of effect and web is called a yarn repeat. The repeat length is the sum of all effect lengths and web lengths. Effect yarns are becoming increasingly important. Areas of application are, for example, denim materials, materials for casual clothing and home textiles.
[0004] Effect yarns can also be produced on rotor spinning machines. In order to produce effects in the yarn on rotor spinning machines, the fiber feed to the opening roller of the rotor spinning device can be changed, for example, in that the speed of the draw-in rollers is varied.
[0005] When the thread run at open-end rotor spinning machines has been interrupted by a thread break or as a result of a cross-wound bobbin change or as a result of the cutting process after a detected, intolerable yarn defect, the thread has to be rejoined. A piecer of this type differs with regard to its diameter, in particular in the case of yarn with a diameter that remains the same, from the remaining spun yarn. The formation of piecers in rotor spinning is described, for example in DE 40 30 100 A1 or the publication, Raasch et. al. “Automatisches Anspinnen beim OE-Rotorspinnen”, MELLIAND Textilberichte April 1989, pages 251 to 256.
[0006] In order to carry out the piecing process, a piecing unit which can be moved along the rotor spinning machine is generally delivered to the respective spinning station. In this case, the normal thread run is changed at the spinning station for piecing and control of the yarn formation is taken over by the piecing unit. During piecing and the subsequent run-up of the rotor, the thread can be drawn off, for example, from the spinning rotor by draw-off rollers, which are controlled by the piecing unit. Until the operating rotor speed has been reached, the take-off speed follows the increase in the rotor speed. Once the spinning rotor has reached its operating speed, the thread is returned to the normal thread run at the spinning station. With the transfer of the thread, the piecing process is ended. Control of the yarn formation is taken over again by the control device of the spinning station or the associated group control. In the known production of effect yarn on open-end rotor spinning machines, the program for forming effects also starts up again from this time. Yarn with effect formation adjoins the piecing region. The piecing region downstream from the piecer, depending on the drawing, can be several meters, with high drawings up to five meters.
SUMMARY OF THE INVENTION
[0007] The object of the invention is to improve the quality of an effect yarn, which comprises piecers.
[0008] This object is achieved by a method for producing an effect yarn on an open-end rotor spinning machine, wherein the effect yarn is formed from an alternating line-up of webs and of effects consisting of predetermined thickenings, and in which the effect yarn is reconnected by means of a piecer after yarn interruptions. According to the present invention, an effect formation is carried out in the yarn in the piecing region following the piecer, which comprises the run-up phase of the spinning rotor. The object of the invention is further achieved by an effect yarn which is formed from an alternating line-up of webs and effects consisting of predetermined thickenings, wherein the effect yarn also has effects in the piecing region of the yarn directly following a piecer.
[0009] The invention proceeds from the recognition that a yarn section with a diameter that remains the same in the finished product, for example in a woven textile, into which the effect yarn is processed, can be visually detectable and can be perceived as an imperfection, which signifies a quality defect.
[0010] Deviations from predetermined effect parameters of an effect yarn caused by piecing regions are reduced or eliminated by means of an embodiment according to the invention. The effect should be configured for this purpose at least so true to the original that disruptions owing to deviating yarn parameters can no longer be directly detected in the finished product.
[0011] According to one feature of the invention, the effect formation in the piecing region is expediently additionally controlled by the control of a piecing unit, which controls the yarn formation during the piecing process. For this purpose, only a corresponding configuration of the programming is needed. Structural changes are not necessary for this.
[0012] In a common drive of the draw-in rollers of the spinning stations, the drive coupling is separated and the drive is carried out mechanically via a drive cone directly by the piecing unit in such a way that the corresponding effects are formed.
[0013] If individual drives for the draw-in rollers are present at the spinning stations, the control thereof also directed to the effect formation can also take place from the piecing unit or also from a workstation control. The effect formation in the piecing region can thus be carried out particularly quickly and effectively.
[0014] If the effect is formed as a continuation of a yarn repeat which is discontinued owing to the yarn interruption, a good connection to the originally predetermined configuration of the effect yarn is possible.
[0015] If the effect formation begins after the piecer with the formation of a web, the checking of the piecer can take place unimpaired.
[0016] Owing to the formation of effects beginning downstream from the piecer, an effect yarn of high quality is produced with a visually advantageous, always uniformly continued alternation of effects and webs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention will be described in more detail with the aid of an embodiment. In the drawings:
[0018] FIG. 1 shows a simplified schematic view of a workstation of an open-end rotor spinning machine,
[0019] FIG. 2 shows an idealized schematic view, not to scale, of a part of an effect yarn with piecer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The embodiment of FIG. 1 shows a spinning station 1 of an open-end rotor spinning machine. The spinning station 1 has an opening device 2 into which a fiber band 5 is introduced by means of the draw-in roller 4 . The draw-in roller 4 is driven by the continuously adjustable draw-in motor 3 . The fiber band 5 is presented to an opening roller 7 which is rotating in the housing 6 and opens the supplied fiber band 5 into individual fibers 8 . The separated fibers 8 arrive through the fiber guide channel 9 onto the conical slip face 10 of a spinning rotor 11 and from there into the fiber collecting groove 12 . From the fiber collecting groove 12 , the yarn is drawn off through the thread draw-off tube 17 in the direction of the arrow 18 with the aid of a draw-off mechanism 19 . The effects of the effect yarn 16 can be determined by corresponding activation of the draw-in motor 3 . Owing to different fiber doubling in the fiber collecting groove 12 , the effect yarn 16 drawn off from the fiber collecting groove 12 has the effects. The spinning rotor 11 is fastened on a shaft 13 , which is mounted on a washer disc mounting 14 and is driven by means of a tangential belt 15 .
[0021] The draw-off mechanism 19 for the spun yarn has a pair of rollers. During normal spinning operation, the effect yarn 16 , after the draw-off mechanism 19 , follows the dashed line 16 A and is then wound continuously onto a cross-wound bobbin, not shown here. For piecing, a piecing unit which can be moved in each case along the rotor spinning machine is delivered to the spinning stations and carries out the piecing process. The piecing unit is not shown in more detail here for reasons of simplification.
[0022] After completion of the piecing process, a check can be made as to whether piecing has taken place properly. For this purpose, the effect yarn 16 is guided section-wise in the piecing unit, which is indicated schematically by the yarn displacement between the draw-off mechanism 19 and a thread guide 20 . The effect yarn 16 runs in the piecing unit, not shown in more detail here, between two further thread guides 21 and 22 through a sensor device 23 , with which the yarn diameter is continually measured during the piecing process. The checking signals for the yarn diameter measured values per unit length are supplied to a control device 24 of the piecing unit. A clearer 25 is connected in the thread run downstream from the thread guide 20 . The clearer 25 comprises a sensor device and a cutting device.
[0023] If a cutting signal is triggered, the cutting device of the clearer 25 is activated and cuts the effect yarn 16 .
[0024] The yarn diameter is checked during the run-up of the spinning rotor 11 at the accelerated effect yarn 16 . After piecing, the effect yarn 16 , corresponding to the increasing spinning rotor speed, is drawn off at an increasing speed from the thread draw-off tube 17 by means of the draw-off mechanism 19 . So the measuring frequency of the sensor device 23 can be adjusted to the changing speed of the accelerated effect yarn 16 , pulses are picked up by means of a sensor 27 from the thread draw-off roller of the draw-off mechanism 19 driven by a drive 26 . These pulses provide information about the draw-off speed of the effect yarn 16 . The sensor signals are fed to the control device 24 , which controls the measuring frequency of the sensor 27 and adapts it to the yarn draw-off speed. As an alternative, the yarn speed can be determined by contactless measuring, for example, directly on the yarn. The control device 24 is connected to a control mechanism 28 of the spinning station 1 . The control mechanism 28 is connected to further modules of the spinning machine via the line 29 .
[0025] Further details of spinning stations of this type and the piecing process can be inferred, for example, from DE 40 30 100 A1 or the parallel U.S. Pat. No. 6,035,622 and the publication Raasch et. al. “Automatisches Anspinnen beim OE-Rotorspinnen”, MELLIAND Textilberichte April 1989, pages 251 to 256.
[0026] FIG. 2 shows the effect yarn 16 in the form of a curve 30 , which has been formed from a line-up of the continuously detected yarn diameter measured values of the effect yarn 16 . In order to make the web thickness and the different effect thicknesses more recognizable, these are exaggerated in comparison to the yarn length. The diameter D of the effect yarn 16 is shown as a percentage on the ordinate of the coordinate system of FIG. 2 . The value 100% corresponds to the web thickness, which is always the same in the embodiment. The yarn length L of the effect yarn 16 is given in mm on the abscissa of the coordinate system. The section represented by the course of the curve 30 , of the effect yarn 16 , which comprises the piecer 31 , has a length of about one metre.
[0027] In FIG. 2 , beginning on the left in the course of the curve 30 , the last effect 32 before the end of the effect yarn 16 , which has been returned for piecing, is shown. The part of the web 33 following the effect 32 has been introduced as a yarn end into the spinning rotor 11 for piecing. The effect 32 has an effect thickness of 150% of the web thickness. The line 34 indicates the location, at which the formation of the effect yarn 16 according to the specifications of the yarn repeat was interrupted. The piecer 31 then follows and subsequently the web 35 . The line 36 indicates the location at which the formation of the effect yarn 16 according to the specifications of the yarn repeat was continued. Following on from the web 35 is the first effect 37 in the effect yarn 16 , which has been formed as a continuation of the yarn repeat. The effect 37 has an effect thickness of 130% of the web thickness. Following on from this in the course of the effect yarn 16 shown, are the web 38 and the second effect 39 . The effect 39 has an effect thickness of 125% of the web thickness. The web 40 and the third effect 41 then follow. The third effect 41 has an effect thickness of 150% of the web thickness. The web lengths of the webs 33 , 35 , 38 , 40 and the effects 32 , 37 , 39 , 41 are configured, like the effect thicknesses, in each case, according to the specification of the yarn repeat.
[0028] In the case of a yarn interruption, the formation of the effect yarn 16 in the spinning rotor 11 is also stopped. The yarn repeat may be stored in the control mechanism 28 , for example. The location of the yarn repeat, at which the formation of the effect yarn 16 according to the specifications of the yarn repeat was interrupted, is also stored by the control mechanism 28 .
[0029] After a yarn interruption, the piecing process is initiated and, during the piecing process, the fiber feed into the spinning rotor 11 is controlled via the draw-in motor 3 in such a way that the piecer 31 can be formed. The formation of the effect yarn 16 according to the specifications of the yarn repeat immediately follows the formation of the piecer 31 . The effect formation can also be acted upon via the changing of further parameters, such as, for example the yarn rotation, in addition to the control of the draw-in motor 3 . The formation of the effect yarn 16 according to the specifications of the yarn repeat is continued with the formation of the web, at which or before which the yarn interruption was executed.
[0030] The invention is not limited to the embodiment shown. Further embodiments are possible in the scope of the invention.
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The aim of the invention is to produce an effect yarn on an open-end rotor spinning machine, formed from an alternating line-up of yarn sections and effects consisting of pre-determined thickenings. To this end, an effect is produced where the yarn is joined by means of a piercing end, in the piercing region of the yarn located downstream of the piercing end, following a break in the thread. The invention enables the quality of the yarn produced in this way to be improved such that unwanted deviations from the pre-determined repeat of pattern of the effect yarn, caused by piercing regions, are eliminated.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2006/066528, filed Sep. 20, 2006 and claims the benefit thereof. The International Application claims the benefits of German application No. 10 2005 047 543.4 DE filed Sep. 30, 2005, both of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a method and an apparatus of a controller and/or machine response of a machine tool or of a production machine.
BACKGROUND OF INVENTION
[0003] As requirements relating to quality and economic viability become more stringent in the field of application of machine tools and production machines, with machine tools and production machines also encompassing robots, the complexity of such machines increases constantly. Novel machine kinematics and complex mechatronic functions require increasingly high performance functions for mechanical systems, drives and controllers. However these are not always easy to develop and design. Therefore manufacturers increasingly have an urgent need to evaluate and optimize the productivity of a machine, the exact response of controller signals, sensor signals and individual axial movements previously used for collision control with the aid of simulation during product development. Simulation here can reproduce the mechanical response of the machine, the response of the drives and also the function of the controller. Only then is it possible to model the temporal response of the mechanical system, the drives and the numerical controller precisely, for example to simulate NC machining or tool changes.
[0004] Models with varying degrees of detailing are currently used to model the mechanical response of machine tools, for example:
[0005] geometric kinematics models (these only take into account geometry, not mass and elasticity of machine elements),
[0006] substitute models for process simulation, e.g. Petri networks, networked function modules,
[0007] models for rigid multi-body systems (in particular in conjunction with flexible connecting elements),
[0008] multi-mass models (these also take into account mass and elasticity in the drive train),
[0009] flexible multi-body systems and
[0010] FE models (finite elements allow total discretization of the mechanical system).
[0011] The controller can also be integrated into the model by means of software simulation or the original controller hardware including original software is used. A numerical controller essentially consists for example of a so-called Numerical Control Kernel (NCK), which controls NC-controlled, regulated axes in the composite interpolation system (e.g. covering a circuit) and a Programmable Logic Control (PLC) which generally controls unregulated axes, e.g. for a tool changer. In some applications however the PLC also controls regulated axes. The controller thus likewise integrates regulated axes in the composite interpolation system (e.g. curve tracing) and auxiliary/feed axes, which are traversed in a regulated or unregulated manner.
[0012] If for example a machine tool or a production machine (e.g. a plastic injection molding machine, a printing machine, an automatic packaging machine, etc.) is supplied and installed by the manufacturer, it is initially in a known and defined state. During production the state and configuration data of the machine change due to new production processes, maintenance, repair, wear, etc. Knowledge of the precise state of the machine is frequently necessary, for example:
[0013] to restart a system,
[0014] to schedule the next maintenance operation,
[0015] to carry out production planning,
[0016] to allow a simulation of the current machine model and/or
[0017] to optimize a new parts program based on the current machine state.
[0018] Continuous acquisition and documentation of the necessary state parameters of the machine tool is complex and therefore does not happen.
[0019] Geometric, technological, economic and qualitative parameters for example are specified for the construction of a workpiece on a machine tool. These parameters restrict the selection of the manufacturing machine tool accordingly. Therefore in order to be able to manufacture the workpiece optimally on a machine tool, it is necessary to have precise knowledge of the capacity and technical possibilities of said machine. The scope of the technological parameters complicates on the one hand the selection process for the most suitable machine tool and on the other hand the NC program design by the NC programmer. Both tasks require very broad technical experience and precise knowledge of the machine parameters and machine technology. The most suitable machine tool results from maximum compliance with different specified criteria for manufacture (e.g. relating to manufacturing costs, surface quality, output, size, technology, etc.). The optimum NC program results for example from a combination of best workpiece quality and shortest production time. The decision regarding the machine on which a workpiece should be manufactured has hitherto been made by operators based on their experience and their knowledge of the machine.
[0020] The operator can also use a simulation to decide which machine tool to select. If the machining of a workpiece is simulated, a separate simulation run has to be carried out for each machine. This procedure can of course also be used for production machines. To simulate a machine tool it is necessary to know the NC parts program. Until now these programs were created either with the aid of a CAM system at the preparatory stage or on site directly at the machine tool.
[0021] A more reliable but also more cost-intensive approach both to machine tool selection and NC program optimization to date has been to manufacture a sample part on the respective machines. This workpiece is then assessed visually. Precise measurement of the sample parts is very cost-intensive and time-consuming. If a manufactured sample part meets the required criteria best, the machine tool used to manufacture this sample part is selected for the manufacturing task. The same also applies to the design of NC programs. If the quality of the sample part is optimal, NC programming can be terminated at the parts program. The presence of a programmer or production planner on site at the machine is necessary for both applications.
SUMMARY OF INVENTION
[0022] An object of the invention is both to allow improved simulation of a controller and/or machine response of a machine tool or of a production machine and also to utilize the simulation results better.
[0023] The object is achieved with a method with the features as claimed in an independent claim and an apparatus with the features as claimed in a further independent claim. Subclaims relate to advantageous developments of the invention.
[0024] With an inventive method for simulating a controller and/or machine response of machine tools or of production machines, data relating to the machine tool or production machine is transmitted from these to a simulation facility by means of an intranet and/or internet. The data here relates in particular to state data and/or parameter data, which can be modified for example during commissioning and/or optimization of the machine. It includes for example gain parameters, idle times, delay elements, parameters for integration elements of a regulator, etc. Data can also relate for example to information about a performance, control quality, a configuration stage of the machine, etc. This data is data relating to the production machine or machine tool, with this data also including data from facilities for regulating and/or controlling the production machine or machine tool. The data is in particular parameter data and/or configuration data and/or hardware data and/or program data, e.g. a parts program, and/or performance data.
[0025] The data from the machine tools or production machines is transmitted from these by way of a network to the simulation facility. This means for example that a regulation facility and/or a control facility, provided to regulate and/or control the machine tools or production machines, transmits the data to a server. The server is connected by way of the internet to a further server, with the further server receiving the data. The further server is then itself the simulation facility or it transmits the data to the simulation facility connected for data purposes to the further server.
[0026] If the machine tools or production machines have a regulation and/or control facility, in an advantageous embodiment this regulation and/or control facility can be simulated or emulated on a separate computer or the downstream computer. The computer is the simulation facility, with the computer and machine being connected to each other for data purposes in a local network with worldwide distribution. The computer for example accepts a connection to the real machine to upload the current configuration of the machine (machine data). Downloads can also be performed.
[0027] If the simulation facility does not use the original regulation and/or control facility, the inventive apparatus can be set up using standard hardware, despite the often different, machine-related controller hardware of the machine. This method advantageously uses a virtual NCK on the simulation facility.
[0028] In a further embodiment the simulation is carried out on the simulation facility in real time. This allows a user to have a temporally correct representation of a manufacturing process in a simple manner.
[0029] According to a further embodiment of the invention configuration data and/or state data of the production machine or of the machine tool is transmitted to a simulation model synchronized with the production machine or machine tool. The simulation model is calculated on the simulation facility. Synchronization here relates in particular to an identical database used and/or a temporally synchronous simulation.
[0030] Until now planning and monitoring systems for a production and/or manufacturing plant were based on states of the production and/or manufacturing facilities other than those that actually occurred in reality, since changes were not taken into account. This affected for example the configuration of the tools, the wear to machine elements, etc. As a result, until now it was frequently only established immediately before or even during manufacture that operating means or tools were unsuitable or missing, so that manufacturing orders had to be rescheduled at high cost. The inventive transmission of data to the simulation facility improves the simulation and therefore also the planning methods associated therewith. The transmission of wear data to the simulation facility in particular contributes to this.
[0031] The transmission of data to the simulation facility is initiated for example by an operator of the machine tool or production machine or is automatic in a further embodiment of the invention. Automatic transmission of the data to the simulation facility takes place at least for example after modification of a data item from the set of data, with this data item at least being transmitted to the simulation facility. It is possible therefore either to transmit all the data or advantageously only the data that has been modified since the last data transmission is transmitted.
[0032] The inventive method can also be developed in that:
[0033] in the case of machine tools the sample workpiece is manufactured on one or more machine tools in a simulative manner by means of the simulation facility using data-based models of one or different machine tools and a data-based model of the workpiece and
[0034] in the case of production machines the sample production item is manufactured on one or more production machines in a simulative manner by means of the simulation facility using data-based models of one or different production machines and the data-based model of a production item.
[0035] Since this method uses a system which has a computer as the simulation facility for example, with the computer being connected to the facility for controlling and/or regulating the machine tool and/or production machine by way of the intranet and/or internet for the purposes of exchanging data, the simulation facility can be used for a number of machines at different locations worldwide. This improves utilization of the capacity of the simulation facility and allows a global comparison of machines. For this it is necessary for the simulation facility or a facility connected thereto, which is therefore part of the simulation facility, to store data from a number of machine tools or production machines, with simulation results of at least two machine tools or production machines in particular being compared automatically and/or being able to be compared by way of a human-machine interface (HMI).
[0036] A simulation system for the machine tool is for example present on the computer for simulation purposes, said simulation system being made up of controller models (for controller emulation), kinematics and the machining process and being able to be expanded using further models. It can be determined from an automated comparison of simulation results which production machine or machine tool best meets the requirements relating to quality, quantity and/or economic viability individually or in combination. Thus a method and/or system is proposed, with which simulation results are further processed using the simulation facility and/or an additional facility in such a manner that a machine tool or production machine is proposed for real use after the simulation of at least two machine tools or production machines.
[0037] In a further embodiment of the method data relating to the machine tools or production machines for the simulation is modified on the simulation facility. This data relates for example to parameters of a regulator or even data which can be used to simulate possible configuration stages of the machine. After the modification of at least one data item or even a number of data items a simulation is carried out on the simulation facility for example using the amended data. After modification modified data can also be transmitted to the machine tool or production machine without further simulation. It is advantageous if simulation results are stored, on which different data sets are based, so that these can be compared. After the comparison and in particular after a qualitative automatic evaluation of the simulation results, the qualitatively better data set or machine is selected, whereupon at least the data of the selected data set that is different from the data stored by the machine tools or production machines is transmitted to these. It is also possible to transmit the entire data set. The transmitted data is used in particular for reparameterization of a controller or regulator.
[0038] A consistent simulation model of a machine tool or production machine can be achieved with the inventive method. The state of:
[0039] emulation of the controller and/or regulator,
[0040] the kinematics simulation,
[0041] the drive technology simulation and/or machining process simulation
[0000] is advantageously in the same state as the real machine tool at all times. The time here relates at least to the time of the simulation.
[0042] The simulation model, which is consistent at all times with the real machine tool or production machine, allows the investigation of the impact of changes to a manufacturing system as a whole. The data determined from the model can be included in short and long-term manufacturing planning and can be used to optimize the manufacturing process at the machine tool or the overall manufacturing process in a manufacturing system.
[0043] Simulation results and/or stored data from the machine tool or production machine are used in a further variant for starting up and/or closing down a production machine or machine tool in a protected manner.
[0044] Simulation results and/or stored data from the machine tool or production machine can also be used in a CAM system for manufacturing planning. This relates in particular to data relating to one or more tools.
[0045] The invention also has the advantage that the continuous documentation of the machine state that is now possible allows more precise planning of maintenance work. Such planning can be automated, with planning being optimized for example with the aid of a trend analysis of the existing data.
[0046] The invention also relates to an apparatus for carrying out one or more of the method steps described above. For this purpose the apparatus has a simulation facility, which is provided both to carry out a simulation step and also in particular to carry out a comparison step for simulation results.
[0047] By connecting the simulation facility to the machine by way of a network, such as the internet for example, it is possible to achieve at least one of the following points:
[0048] use of the current configuration of the machine for starting up a controller emulation on the computer;
[0049] use of the controller emulation to carry out the simulation of a machining task using the configuration data of the machine;
[0050] linking the controller emulation to models for simulating the drive, mechanical system (e.g. kinematics), and/or the machining process (e.g. material removal);
[0051] evaluating the simulation results in the context of machine selection, e.g. in the case of machine tools, determining the machining time, surface quality, compliance of all measurement points, machining costs and/or machining quality, with the aid of the simulation of the machining task on the simulation facility;
[0052] aligning the simulation results with the model data of a workpiece to be manufactured in the context of an NC program optimization. In addition to a precise 3D model, this contains all the relevant manufacturing data available for the alignment;
[0053] automated multiple repetition (e.g. by means of a batch operation) of the simulation for different configurations of one or more machines;
[0054] access to functions and data of the simulation facility by way of the intranet and/or internet using a web portal or a client application from further simulation facilities.
BRIEF DESCRIPTION OF THE DRAWINGS
[0055] Exemplary embodiments and/or further embodiments of the invention are described in more detail below and illustrated in the drawing, in which:
[0056] FIG. 1 shows a first illustration of the invention and
[0057] FIG. 2 shows a further illustration of the invention.
DETAILED DESCRIPTION OF INVENTION
[0058] The illustration according to FIG. 1 shows a symbolic diagram of a machine 1 . The machine 1 is a machine tool for example, which has a CNC (Computer Numerical Control), or a production machine. Data 5 is stored in the machine 1 . This data 5 can be transmitted by way of an internet 2 by means of a data transfer 4 to a simulation facility 3 , with the data relating for example to configuration data, wear data and/or traces. The simulation facility 3 is for example also a system for monitoring manufacturing and/or production planning. The simulation facility 3 is provided in particular as a controller emulation and/or as a facility for executing other simulation models (e.g. simulation with a CNC emulation), with persistent storage of model process data being carried out for example in the simulation facility 3 .
[0059] A number of different data items 5 from one or more machines (not shown) are stored on the simulation facility 3 . The data 5 is used for a simulation 7 on the simulation facility 3 , with simulation results 8 being made available after the simulation 7 . The simulation results 8 show how the machine response of a machine changes with different data and how a number of machines differ from each other in their response. The simulation results 8 can also be used to carry out a setpoint/actual comparison between the simulation and reality.
[0060] The simulation results 8 are compared in a comparison step 9 and/or transmitted by way of the internet 2 . The comparison gives rise to comparison results in such a manner that specific data items 6 can be preferred. The preferred data items 6 are then transmitted back to the machine 1 . These data items 6 relate in particular to correction data for implementing measures to improve the machine response. The corrections are made automatically for example after the comparison of the simulation results, with a new simulation with the corrected data being possible. The machine 1 is operated with the preferred data items 6 by the end of the method. The simulation results 8 also allow a trend analysis for example, it being possible also to derive measures relating to a data modification herefrom.
[0061] An inventive system allows an automatic adaptation of machine tool simulation models. The system has the simulation facility 3 , which is a computer for example, which is connected to controllers of machine tools by way of the intranet or internet for the purpose of exchanging information. A simulation system for the machine tool is present on the computer. Data 5 from the real machine tool 1 is transmitted to the models of the simulation system (e.g. for controller, drive technology, workpiece, tool and machine tool) and documented there. The system can be expanded according to requirements with further state data and models of the machine tool.
[0062] The system and a method based thereon have at least one of the following features in particular:
[0063] an accepted connection from the simulation facility 3 to a real machine 1 for transmission of the current configuration (machine data) and state data;
[0064] current configuration data and state data is used to keep the simulation model consistent with reality;
[0065] the configuration data is the machine data of a numerical controller (including drive and tool data);
[0066] the state data is process data (e.g. axial positions) and machine or tool characteristics influenced by wear, working life or service life;
[0067] the simulation model includes an emulation of the controller, a simulation of the kinematics, the drive technology and/or the machining process;
[0068] an interface with the simulation facility allows access to data from the simulation facility 3 by way of the intranet or internet 2 from further simulation facilities (not shown).
[0069] The diagram according to FIG. 2 shows a server 11 . A programming station 12 is connected to the server for data purposes. The server 11 is designed as a simulation facility, with simulation results being transmitted to the programming station 12 for example by way of the internet 2 . In one embodiment (not shown) the programming station 12 is integrated in the machine 1 . This integration is either a local integration or a functional integration. The programming station 12 should be considered part of the machine 1 even in the case of a functional integration. Parts programs, workpiece models (CAD, 3D, etc.) production requirements and/or quality criteria can be transmitted from the programming station 12 to the simulation facility 11 by means of the data transfer 4 by way of the internet 2 . Machine data from the machine 1 can be transmitted to the simulation facility 11 . From the simulation facility 11 a new parts program can be transmitted to the machine 1 by way of the internet 1 .
[0070] Use of an inventive system means that the machine selection is no longer made just on the basis of poorly defined empirical values but with the support of a transparent evaluation. This avoids expensive estimation errors. This relates both to the use of existing machines and the purchase of new machines.
[0071] The system and a method based thereon in particular has at least one of the following features or a corresponding advantage:
[0072] the system offers a workpiece producer the possibility of including in the comparison machines which are not (yet) physically available, as machine producers can offer their machines globally using this system;
[0073] the simulation can on the one hand be operated by the party wishing to manufacture the workpiece so that the workpiece model does not have to be disclosed and know-how protection is maintained;
[0074] the simulation can be outsourced to a reliable entity, so that know-how protection can be ensured both for the machine producer and for the workpiece manufacturer;
[0075] the system can serve a manufacturing planner beforehand when selecting a machine or can for example assist the NC programmer when generating a sub-program for a current machine configuration;
[0076] the NC programmer no longer has to be on site to create and test the NC program but can operate anywhere by way of the software system;
[0077] the NC programmer is able to simulate his/her NC programs locally on his/her PC or to outsource them as a simulation order to a reliable entity (computer);
[0078] the NC programmer can use this system to design programs both for machines in his/her own company and for external machines connected to the computer. This makes global commissions a possibility.
[0079] the NC programmer can use this system to tailor parts programs to the current machine configuration and thus ensure functionality.
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There is described a method and device for simulating a control and/or machine behavior of machine tools or production machines, in which data concerning the machine tools or production machines are transmitted to a simulation device by mans of an intranet and/or by means of an internet. The data can be automatically transmitted to the simulation device, whereby particularly after a change in an item of data from the quantity of data, this item of data is transmitted to the simulation device.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/716,045, filed Sep. 12, 2005, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an integrated laboratory light fixture, which combines a light, an air vent, and other device fixtures for use in a suspended ceiling grid or sheetrock system, and more particularly to an integrated laboratory light fixture design that promotes safety in facilities with critical airflow pattern requirements (such as labs, pharmaceutical, food, medical and healthcare applications), and reduces facility capital, energy and operating costs.
BACKGROUND OF THE INVENTION
[0003] Suspended ceiling systems are extensively used throughout the construction industry, both in new building construction and in the renovation of older buildings. A suspended ceiling consists of a grid-like support base suspended from the overhead structure, the base supporting a layer of ceiling panels. In addition, the suspended grid frequently serves as a support base for lighting fixtures and heating and air conditioning outlets, fire sprinklers, sensors, detectors, monitors, enunciators, speakers, and other such items. Ceiling space constraints often create difficult choices in controlled environment facilities because of competition for the optimum air outlet locations. Whenever hoods or containment devices are lined up at the room perimeter, the best air outlet locations are in the center, which is often where the benchtops and lighting are needed. The competition for space with lighting and other ceiling devices may lead to imperfect air outlet locations and potentially undesirable large scale airflow patterns (eddies). Many times the dynamic controls for the room HVAC (heating, ventilating and air-conditioning) system contributes to variable large scale airflow eddies which decrease the containment efficiency of hoods and other exhausted devices. These eddies create cross drafts that impair proper hood functioning. Usually, cross drafts require hood performance enhancements through increased exhaust and supply air flow rates, which lead to increases in energy costs. The design engineers must address all of these concerns, but the equipment available today does not lead to easy solutions. Once these considerations are addressed in high tech facilities, much of the ceiling tiles are no longer removable because of the devices rigidly mounted in them. This leads to difficult compromises that impair above ceiling access and facility maintenance operations.
[0004] There have been several past combination lighting and HVAC fixtures, but most applications have been intended for ceiling mounted clean room filtration. These inventions do not address the safety issues of hazardous compound containment devices (hoods and other exhausted cabinets) by promoting uniform room scale airflow patterns and minimizing cross drafts. In addition, the energy efficiency of the lighting and airflow control has not been combined in other products currently available. A fixture with a design focused on recyclability and is made from mostly recycled materials is not available today, but is needed in Green Building applications.
SUMMARY OF THE INVENTION
[0005] The present invention has as an underlying objective, the improvement of controlled environment facility safety while improving life cycle facility costs. The integrated laboratory light fixture (or “lablight’) resolves the problem of competition for the ceiling space in the center of facilities with containment devices along the perimeter walls. In doing so, the capital costs of ceiling mounted equipment and associated installation costs are reduced. The operating cost of the facility is minimized by preventing hood airflow increases to resolve cross draft problems. Also, facility reliability enhancements come from improved above ceiling access inherent in the integrated design philosophy.
[0006] The integrated lablight provides shadow free lighting of various intensities along with air outlets and locations for a wide variety of other ceiling mounted devices. This improves facility installations by ensuring the design intent is not compromised through unintended air outlet or lighting locations; the ceiling device locations are built in to the integrated lablight so the design intent is correctly applied every time.
[0007] The integrated lablight is comprised of light fixtures designed to provide various levels of shadow free light on a work surface along with air outlets for room temperature control and ventilation. The top surface and central structure are joined with a bottom plate to form a rigid, air tight structure. An air supply duct connection point in the center of the upper portion routes air through a flow straightener then an adjustable flow splitter. The air then flows around the central light fixture and out through a series of slots arranged symmetrically perpendicular to the fixture axis. The air slots are designed to minimize turbulence and eddies while promoting air mixing for temperature stability. The airflow pathway keeps the light lenses free from dust by washing over the lens surfaces. At the fixture perimeter is a dark colored lip to enhance ambient room air mixing with the supply air stream while providing a concealed area for ambient dust collection. This provides protection for the light fixtures and a convenient method of fixture cleaning.
[0008] The lighting is designed to provide consistent, uniform and shadow free lighting at a work surface below. Two or three lighting locations within the fixture minimize the opportunities for shadows on work surfaces. Also, the lighting type and strength may be configured for many specific job applications. A variety of lighting types, lenses and diffusers, reflector shapes and designs are matched to client requirements including fluorescent multiple tube fixtures, LED (light emitting diode), sodium, incandescent, and metal halide.
[0009] The integrated lablight attaches to the ceiling structure (sheetrock or suspended ceilings) for a sealed air tight installation. The lighting equipment (including ballasts, transformers, etc.) is located in the upper area for cooling by ambient plenum air above the ceilings. A variety of electrical power connection locations provide flexibility in tightly constrained ceiling spaces. The designated locations for mounting other ceiling devices frees up maintenance accessibility for faster diagnostics, problem resolutions and future facility modifications. The integrated temperature sensor locations accommodate stable lab environmental controls with locations for ambient and supply air temperature sensors. The overall integrated design philosophy saves equipment, installation, and operating costs and results in safer labs.
[0010] A variable air volume (VAV) hood control systems are common because they provide the most value in a market of increasing energy costs. The resultant dynamic conditions may contribute to hood challenges and must be considered in the design process. Occupant thermal comfort may be impacted when the control system compensates for rapid changes in airflow requirements, because the reheat water valve may not respond quickly enough. When a VAV hood sash is opened, the supply and exhaust air flows increase rapidly to compensate for the sudden demand. Lab personnel may be subjected to colder than normal air unless the heating hot water valve anticipates the increased supply air flow rate. The correct amount of heating hot water supply is best determined from diffuser discharge air temperature measurement in addition to room ambient temperature. The integrated lablight provides engineered mounting locations to ensure proper temperature control measurement of supply air temperature and ambient room temperature. The integrated design removes the opportunities for unplanned changes in device location in the construction phase of facility procurement, so the designer's intent is guaranteed to be implemented for increased safety and effectiveness.
[0011] In accordance with one embodiment, a ceiling mounted sealed fixture that enhances safety by providing designers with lighting in combination with a uniform, even, and optimized air flow source, and a mounting location for other ceiling devices; this arrangement supports an integrated design approach that results in minimizing cross drafts to facilitate the containment of hazardous substances; optimizing maintenance access by reducing ceiling space constraints, provide uniform lighting with a minimum of shadows, and saving capital and operating costs for building owners; the combining of lighting with air vents enables HVAC designers to use space over tabletops for air registers to optimize room level airflow patterns without sacrificing lighting quality; the multiple light sources inherent in the integrated lablight represent an improvement over current lighting designs by providing uniform light intensity while minimizing worksurface shadows; the integrated lablight fixture provides precise locations for temperature control sensors, which promotes improved temperature stability for temperature sensitive equipment located below the fixture; for rooms with significant containment exhaust requirements, the fixture (lighting and supply air outlet) is designed to be located along the lab's central axis to create a sweeping airflow from center of the lab to the perimeter; the linear shape of the fixture enables their alignment in a row along the center of a lab to maximize the overall room airflow patterns and ambient air mixing; for rooms with excessive heat generating equipment, the fixture can be used in the exhaust mode; an integrated fixture that provides a room side means of adjustment for overall airflow and symmetry of airflow; the use of CFD analysis to optimize the surface features of the air vent design to achieve desired room level airflow patterns; fluorescent tube T- 5 fixture with reflector (parabolic, non-linear or other type) and/or luminare lens to optimize lighting uniformity or focus over desired surfaces; CFD (compact fluorescent device) instead of fluorescent tube in item 1 g; LED instead of fluorescent in item 1 g; light lens remains dust free with layer of supply airflow, and a perimeter ambient air guide trough promotes the cleanliness of the fixture and lighting lenses by intercepting any room dust or debris due to the aerodynamic design; an airflow exit slot designs and exit velocities are designed to deliver low speed, uniform airflow with any potential eddies oriented in the axial direction to minimize eddies in the transverse direction. This arrangement allows optimized room level airflow patterns when the fixtures are mounted in a central line; it promotes strong and consistent room air mixing for temperature stability while minimizing cross drafts, which may impair the operation of hoods; and fixture housing provides a seal at the ceiling level to minimize unwanted air transfer between the room and the adjacent areas; fixture design can support a dimmable lighting system with remote control connection points.
[0012] In accordance with a further embodiment, a fixture for suspended ceiling systems, comprising sheetrock or other ceilings that improves overall above ceiling access by providing integral locations for many common ceiling mounted devices; a fixture that eliminates the design conflict between providing air supply and lighting over lab tables; a fixture that provides mounting points for room air and supply air temperature sensors, air quality sensors such as CO 2 , O 2 , VOC and other detectors, optical and acoustic sensors, radiation and other sensors, sprinkler heads, pressure ports, and environmental monitoring devices; another advantage of the present invention is the arrangement options for locations of electrical connections. The electrical power for the fixture can be connected on the top or the side of the fixture; the low profile and truncated corner edges enable the integrated lablight to be applied in installations with extreme space limitations.
[0013] In accordance with another embodiment, a fixture that saves building owner's money by: eliminating the installation and material handling costs of the air vent (connection costs are retained); minimizes air balancing and commissioning costs associated with non-optimized room level airflow patterns; generally reduces maintenance costs and maintenance response times by improving access to above ceiling devices; reducing costs for installing controls and sensors due to ceiling mounted location with no trim requirements a fixture that saves energy by minimizing airflow increases required for improving hood containment due to excessive room cross drafts, and by providing energy efficient lighting cooled by ceiling plenum air; low profile saves costs with less material used in fabrication; fixture material is predominantly recycled and recyclable; other applications include any room where airflow patterns are critical to the functioning of the facility; other applications include rooms where ceiling space is limited; other applications include rooms where ventilation and lighting are both needed in the same location.
[0014] In accordance with a further embodiment, a ceiling mounted fixture comprises: at least one longitudinal arrangement of at least one air vent adapted to receive an air supply; and at least two longitudinal arrangements of at least one light source, and wherein the at least one longitudinal arrangement of at least one air vent is positioned between the at least two longitudinal arrangements of light sources.
[0015] In accordance with another embodiment, a fixture comprises: a central light source; an air supply duct having a connection point in a center portion of the fixture; and a flow straightener, wherein the flow straightener routes an air supply through an adjustable flow splitter and around the central light source and out through a series of slots arranged symmetrically perpendicular to an axis of the fixture.
[0016] In accordance with a further embodiment, a ceiling mounted fixture system adapted to be located along a lab's central axis to create a sweeping airflow from a center portion of the lab to a perimeter thereof comprises: a plurality of linear fixtures comprising: a central light source; an air supply duct having a connection point in a center portion of the fixture; and a flow straightener, wherein the flow straightener routes an air supply through an adjustable flow splitter and around the central light source and out through a series of slots arranged symmetrically perpendicular to an axis of the fixture; and wherein the plurality of linear fixtures are aligned in a row along the center portion of the lab to maximize the overall room airflow patterns and ambient air mixing.
[0017] In accordance with another embodiment, a ceiling mounted fixture comprises: at least one longitudinal arrangement of at least one air vent adapted to receive an air supply; and at least one longitudinal arrangement of at least one light source adjacent to the at least one air vent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a side elevational view of the shorter length, in cross section, showing a suspended laboratory light and ventilation fixture as mounted in a ceiling.
[0019] FIG. 2 is a side elevational view of the longer length, in cross section, showing additional details relating to additional ceiling device mounting locations and airflow guide designs.
[0020] FIG. 3 is a bottom view showing a room side depiction of the laboratory lighting and air outlets and the airflow guiding surfaces.
[0021] FIG. 4 is an exploded view of a suspended light and ventilation fixture.
DETAILED DESCRIPTION
[0022] Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be fabricated without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
[0023] The integrated laboratory light fixture 100 may take form in various components and arrangements of components, and in various steps and arrangements of steps. Slight modifications and variations to fit specific needs of designers are included in this invention. The drawings are only for purposes of illustrating a preferred embodiment and are not to be construed as limiting the invention.
[0024] The integrated lablight combines lights and HVAC air outlets to promote lab safety by minimizing hood cross drafts. Usage of the fixture also leads to equipment, installation labor, and energy cost savings for lab owners.
[0025] The containment effectiveness of hoods is impaired by cross drafts near the hood face. Good lab designs avoid the placement of supply air outlets near hoods to prevent cross drafts. The air turbulence from cross drafts causes fumes to escape from the hoods, which pose health risks for lab occupants.
[0026] Many dense lab layouts arrange the containment devices (fume hoods, exhaust cabinet, etc.) along the perimeter with lab tables in the center. These layouts are best supported with air supply outlets along the central axis of the ceiling to avoid interfering with hood operation. Often this central ceiling space is used for light fixtures over the central tables, and the air outlets are located elsewhere. In addition, other ceiling devices compete with air outlets for best locations, such as fire sprinklers, sensors, detectors, speakers and specialty lights. Additional air outlet location restrictions come from above ceiling maintenance access pathways, which must be left clear to support proper lab operations.
[0027] These competing requirements for ceiling space often result in less than optimum air distribution patterns that can interfere with hood containment. Air balancing and commissioning activities may require increases in hood airflow rates to ensure lab safety, which increases energy consumption requirements. Many times proper hood finction requires the relocation of some supply air outlets in addition to increasing exhausted air flow quantities. In all cases, reducing laboratory cross drafts improves hood containment effectiveness and enhances safety for the occupants.
[0028] New fume hoods that require lower airflow rates are becoming commercially available and offer safe lab designs with less costly facilities. Many low airflow rate containment technologies are sensitive to interferences from cross drafts, so minimizing lab cross drafts will become increasingly important. In these ways, the usage of the Integrated Lab Light will promote lab safety, increase lab energy efficiency, save owners capital costs, and promote the usage of low flow containment devices for life cycle value enhancement.
[0029] The integrated lablight presents a relatively inexpensive and easily manufactured fixture which can be fabricated in a variety of different configurations for different design applications. The fabrication strategy focuses on sustainable practices (recyclable, energy efficiency) to provide facility owners with increased choices for environmental responsibility. However, it is to be understood that various changes can be made in the arrangement, form and construction of the apparatus disclosed herein without departing from the spirit and scope of the invention.
[0030] FIG. 1 is a side elevational view of the shorter length, in cross section, showing a suspended light and ventilation fixture 100 (or lablight fixture) as mounted in a ceiling. The short side of the 2′×4′ integrated lablight fixture 100 is shown in FIG. 1 . As shown in FIG. 1 , the lablight fixture 100 includes a top portion preferably comprised of a round sheet metal duct connection, which forms a round duct connection 1 with a beaded collar 2 to secure a supply air flexible duct with a hose clamp. Air flows down the round section through an air flow straightener 3 to promote even air distribution, then into a plenum with an air flow guide 4 , which is preferably a curved air guides. On either side of the air outlets, light fixtures are located with reflectors 5 , light bulbs 6 , and lighting diffusers 7 (or lighting lens).
[0031] The integrated lablight can be supported in sheetrock or T-bar ceilings with a strong gasket and clamped perimeter trim 8 . A dark colored perimeter aerodynamic trough 9 (or air ambient air guide) catches ambient room dust and debris to minimize dirt concentrations on the light diffusers 7 . The location to mount fire sprinklers or other sensors or devices to the integrated lablight fixture 100 is shown in this view. The air outlets 11 are preferably shaped and oriented to enhance air supply mixing while minimizing room level turbulence and eddy currents.
[0032] It can be appreciated that the air outlet orientation is designed to wash the lighting diffusers with supply air, which is usually filtered at the air handler. This shape of the air plenum and lighting diffusers guides the supply air over the interior surfaces which helps keep the light diffusers clean to enhance lighting output. The interior air mixing plenum shape 14 (or air flow mixing area) promotes good room air mixing for ambient room temperature control and stability (see FIG. 5 ). The lighting diffuser 12 as shown in FIG. 1 can include an optional third light for higher light output. A central light reflector 5 and a central air flow adjustment guide 13 compensate for any residual eddies resultant from the HVAC air distribution system configurations.
[0033] FIG. 2 is a side elevational view of the longer length, in cross section, showing more details relating to additional ceiling device mounting locations and airflow guide designs. As shown in FIG. 2 , the adjustment points for the central air flow adjustment guide include a structural reinforcement 16 to secure the fixture's shape, and a seismic hanger location 17 for code required support. The fixture also preferably includes a unit support hanger flange with an opening 18 , which provides structural and/or seismic support.
[0034] FIG. 3 is a bottom view showing a room side depiction of the lighting and air outlets and the airflow guiding surfaces. As shown in FIG. 3 , the fixture includes at least one row of air vents or air flow guides 4 and at least two rows of light assemblies comprised of a light bulb 6 , a light reflector 5 , and a light diffuser or light lens 7 . The at least one row of air vents or air flow guides 4 are preferably positioned between the at least two rows of light sources. The fixture preferably has a ratio of length to width of approximately 2 to 1. However, it can be appreciated that the length to width ratio can vary from about 8 to 1 (8:1) to about 1 to 1 (1:1), wherein the length and width of the fixture are approximately equal.
[0035] As shown in FIG. 3 , the fixture 100 preferably includes at least one longitudinal arrangement of at least one air vent 14 adapted to receive an air supply, and at least two longitudinal arrangements of at least one light source 6 , wherein the at least one longitudinal arrangement of at least one air vent 14 is positioned between the at least two longitudinal arrangements of at least one light source 6 . However, it can be appreciated that the fixture 100 can have 1 to 5 longitudinal arrangements (or rows) of light sources or lights 6 and an equal amount, one more, or one less longitudinal arrangements (or rows) of air vents 14 or air flow guides. In addition, the fixture 100 can include at least one temperature control sensor, which promotes improved temperature stability for temperature sensitive equipment located below the fixture. As shown in FIG. 3 , the fixture 100 includes two longitudinal arrangements of air vent 14 and three (3) longitudinal arrangements of light sources 6 , in the form of a tubular light.
[0036] FIG. 4 is an exploded view of the suspended light and ventilation fixture 100 . As shown in FIG. 4 , the fixture 100 includes a duct connection 1 , which is preferably round, a beaded collar 2 , an air flow straightener 3 , an air flow guide 4 , a light reflector 5 , at least one light bulb 6 , a light lens or light diffuser 7 , a ceiling support structure 8 , an ambient air guide 9 , an edge of fixture (in background) 10 , an optional third light lens 11 , an optional third light reflector 12 , an air flow adjustment guide 13 , an air flow mixing area 14 , a plurality of air flow discharge slots 15 , an air flow guide 16 , an edge of fixture 17 , a structural/seismic support 18 , a sprinkler head location or ambient sensor location 19 , and a supply air sensor 20 . The fixture 100 also includes a structural/seismic support location, a central air flow adjustment guide, and an electrical connection, which is preferably a 120 volt/1 inch/60 watt electrical connections with ¾ inch spiral conduit. However, it can be appreciated that any suitable electrical connection can be used. The fixture 100 is preferably constructed of aluminum or other suitable material, which can be recycled or constructed of a material, which is recyclable.
[0037] It can be appreciated that a plurality of integrated laboratory light fixtures 100 can be used to supply an airflow, discharge an airflow, and control an ambient airflow, wherein the ambient airflow is room air that comes in from the side and mixes with the supply air to help maintain overall room temperature uniformity. The fixture 100 is preferably adapted to be located along a clean room's central axis to create a sweeping airflow from center of the lab to the perimeter. In accordance with one embodiment, an array of fixtures 100 can be aligned in a row along the center of a lab to maximize a room's airflow patterns and ambient air mixing. Alternatively, it can be appreciated that the fixture 100 can be used in the exhaust mode for rooms with excessive heat generating equipment. In accordance with another embodiment, the fixture 100 further provides a perimeter ambient air guide trough, which promotes the cleanliness of the fixture 100 and lighting lenses by intercepting any room dust or debris due to the aerodynamic design. In addition, the fixture 100 can include an airflow exit slot designs and exit velocities are designed to deliver low speed, uniform airflow with any potential eddies oriented in the axial direction to minimize eddies in the transverse direction.
[0038] In accordance with a further embodiment, the fixture 100 can include mounting points for room air and supply air temperature sensors, air quality sensors such as CO 2 , O 2 , VOC and other detectors, optical and acoustic sensors, radiation and other sensors, sprinkler heads, pressure ports, and environmental monitoring devices.
[0039] Various other objectives, advantages, and features of the present invention will become readily apparent from the ensuing detailed description, and the novel features will be particularly pointed out in the appended claims. As shown in FIGS. 1-4 , the following reference numbers correlate to the following elements:
[0040] 1 —Round duct connection
[0041] 2 —Beaded Duct Collar
[0042] 3 —Air Flow Straightener
[0043] 4 —Air Flow Guide
[0044] 5 —Light reflector
[0045] 6 —Light bulb or lamp
[0046] 7 —Light Lens/diffuser
[0047] 8 —Ceiling support structure
[0048] 9 —Ambient air guide
[0049] 10 —Edge of fixture (in background)
[0050] 11 —Optional third light lens
[0051] 12 —Optional third light reflector
[0052] 13 —Air flow adjustment guide
[0053] 14 —Air flow mixing area
[0054] 15 —Air flow discharge slots
[0055] 16 —Air flow guide
[0056] 17 —Sheet metal shroud
[0057] 18 —Unit Support Hanger Flange with hole
[0058] 19 —Sprinkler head location or ambient sensor location
[0059] 20 —Supply Air Sensor Location
[0060] It will be understood that the foregoing description is of the preferred embodiments, and is, therefore, merely representative of the article and methods of manufacturing the same. It can be appreciated that variations and modifications of the different embodiments in light of the above teachings will be readily apparent to those skilled in the art. Accordingly, the exemplary embodiments, as well as alternative embodiments, may be made without departing from the spirit and scope of the articles and methods as set forth in the attached claims.
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The integrated laboratory light (lablight) fixture is a sealed ceiling mounted fixture that combines air outlets, lighting and other devices for use in laboratory, clean room, healthcare, educational, and other facilities requiring critical airflow control. The integrated lablight is made for a central location in the lab to eliminate room scale eddies and cross drafts along with the hood challenges they present. The combining of most ceiling devices in one fixture results in a safer environment with greater access for above ceiling maintenance, as well as less expensive facility capital costs. The fixture design also minimizes shadows at the work surface, and promotes temperature stability for temperature sensitive equipment.
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COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND
When considering a purchase or lease of real estate, especially commercial real estate, the potential buyer or lessee has to consider a myriad of attributes of the property. Also, comparison between various alternative properties is difficult. One tool that has been used to simplify the process is the concept of “comparables” or “comps”, i.e., other properties that have similar attributes that can be used for comparison. While the use of comps is often helpful, it is difficult to determine a group of comparable properties because each consumer may have different needs and thus different attributes that need be considered to determine comparable properties. For example, one consumer may want properties that are near a main street, have storefront access and 10,000 square feet of available space while another consumer may need to be in a specific neighborhood and need 50,000 square feet.
In addition to the common attributes, such as the location and size of the building and the available space, a consumer must consider zoning, tenants, price, appearance of the building, vacancy rates, available transportation, age of the building, amenities, various financial attributes, and many other factors to make the best decision. The decision is so complex that professional brokers and other intermediary models have arisen to assist the consumer. In fact, virtually all commercial real estate transactions involve at lest one intermediary.
Recently, databases have emerged that provide access to real estate information, and commercial real estate information in particular. For example, CoStar™, provides a database that can be searched by various attribute filters to provide listings of properties satisfying the filter attributes. Such databases often include a great deal of textual information about properties and images of the properties and related maps. Brokers and other intermediaries use such databases to discover properties and help clients make decisions thereon. Also, these databases can be accessed via a web interface using a standard browser. However, because of the myriad of data, it has been difficult to present the data in a coherent manner, especially on mobile devices with constrained processing and display resources.
By nature, the search for real estate requires a decision maker, e.g. a broker and their client, to physically visit the various properties. Therefore, the difficulty in accessing data is further complicated in that the decision maker is physically on the move. Typically, a broker will conduct a property search at the office and print out the results to take with them to visit properties with their clients. In the event that the client desires different or more specific information while visiting a property, it is difficult for the broker to obtain the information. While real estate information is available through smartphones, tablets and other mobile devices, current systems do not provide the level of interactivity required by mobile devices to effectively utilize real estate information databases on a mobile device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a computer system of an embodiment.
FIG. 2 is a search results screen.
FIG. 3 is a property detail screen.
FIG. 4A is a lease detail screen showing lease transaction information.
FIG. 4B is a lease detail screen showing a “stack plan”.
FIG. 5 is a sale detail screen.
FIG. 6 is a tenant detail screen.
FIGS. 7 and 8 are analytics detail screens.
FIG. 9 is a demographic detail screen.
FIG. 10 shows an alternative query.
FIG. 11 shows a user interface for entering critical dates for a query.
FIG. 12 shows another alternative query.
FIG. 13 is a custom tour creation screen.
FIG. 14 is a tour property rating screen.
FIG. 15 is a rating comparison screen.
FIG. 16 is rental rates comparison screen.
FIG. 17 is a screen showing rental rates plotted against ratings.
FIG. 18 is a cash flow screen.
FIG. 19 is a Lease Discounted Cash Flow screen.
FIG. 20 is a Lease Discounted Cash Flow comparison screen.
FIG. 21 is a screen showing a query matching window.
While systems and methods are described herein by way of example and embodiments, those skilled in the art recognize that the invention is not limited to the embodiments or drawings described. It should be understood that the drawings and description are not intended to be limiting to the particular form disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the appended claims. Any headings used herein are for organizational purposes only and are not meant to limit the scope of the description or the claims. As used herein, the word “may” is used in a permissive sense (i.e., meaning having the potential to) rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean including, but not limited to.
DETAILED DESCRIPTION
It is known to utilize mobile devices, such as smart phones and tablet computers, to assist in mapping/directions and other informational needs. However, tools for mapping have not been integrated into real estate databases in a manner that allows a user to efficiently retrieve data and absorb that data on a resource constrained device. The disclosed embodiment provides an application front end, i.e. an “app” that allows a user, such as a lessee, purchaser, or intermediary acting on behalf of the consumer, the client, to query a real estate database and manage the presentation of the query results in a convenient manner. The app can run on a mobile client device, such as a smartphone or a tablet computer, and the query results can be presented in a manner that permits ease of viewing, ease of analysis, and ease of transitioning to related data.
FIG. 1 illustrates a system in accordance with an embodiment. The system includes server device 10 and one or more client devices 12 a , 12 b , and 12 c , collectively and individually referred to as “client device 12 ” herein. Of course, there can be any number of server devices and client devices and each device can be composed of one or more devices. As an example, server device 10 can be a server farm of many computing devices and memory devices and each client device 12 can be a mobile device such as a smartphone or a tablet computer. Client device 12 can be communicatively coupled to server device 10 through a network, such as the Internet. The communication connection can include wired and/or wireless links. For example, client device 12 can be coupled to server device 10 through WiFi or a 3G/4G cellular network.
Server device 10 includes database 14 of commercial real estate data, including property records, stored and organized in a known manner. For example, a database such as that described in U.S. Pat. No. 7,640,204 can be used as database 14 . Database 14 can also include other information, such as mapping information and contract information, such as lease agreement information, as described below. Database 14 can be composed of plural databases. Also, server device 10 includes process manager 18 which processes queries to database 14 and data returned in response to the queries. Also, process manager 18 can handle the calculation of analytics and other data manipulation, which are described in further detail below.
Each client device 12 has app 16 loaded in a memory thereof. App 16 includes software instructions for facilitating query submission to database 14 presentation of data including data returned in response to queries, and other functions described below. Server device 10 and client device 12 are each one or more computing devices as is well known and include processors, displays, input devices, memory and the like. All functions of the devices are accomplished by software instructions recorded on tangible media and executed by the processors. In the disclosed embodiment, client device 12 includes a touch screen user interface.
Users can access database 14 through a subscription based model, for example. Although the data is described as being contained within a “database,” data can be stored in a plurality of linked physical locations or data sources and thus database 14 can include data stored at various location and on various devices. Database 14 can provide a unified data model and a system for forming a variety of queries. Also, database 14 includes all indexes, data structures, and other elements necessary to process queries and return results. For example, database 14 can be a Structured Query Language (SQL) database.
FIG. 2 illustrates a search results screen of an embodiment that is generated by app 16 and displayed on client device 12 . A search query, in the form of an address, a neighborhood, or a building name, for example, can be entered into search box 20 . In this example, an address was used as the query. Also, various filters, such as For Lease, For Sale, Size, Year Built, Tenants, Zoning, Energy Rating, Building Class, Lease Expiration, Option Type, Hierarchy, Portfolio, Agent/Company/Contact, and the like can be applied at the time of submitting the query or afterward to the results set.
The query is sent to server device 10 and processed by manager 18 . Data from database 14 is returned that satisfies the query. The returned results are shown in map window 22 and record window 24 . Map window 22 shows icons representing properties corresponding to property records returned as a result of the query. Each icon corresponds to a single property. Note that not all properties satisfying the query need be shown as icons in map window 22 . In fact, as described in greater detail below, it is often desirable to limit the number of icons, especially on a mobile device. Record window 24 shows a listing of properties corresponding to property records satisfying the query and related information from the corresponding property records in database 14 . In this example, record window 24 shows the address of each property, an image of the property, and related information, such as available square footage and price for the lease or sale of the property. Selection of a property listing from record window 24 can provide more detailed information for that property, such as leasing contact information and other information described below.
Navigation of the screen shown in FIG. 2 , and all screens described herein, can be accomplished by touch screen input. For example, a user can scroll down the list of properties in record window 24 by dragging a finger upwards in the window. Selecting a property, by touching the corresponding display area, can place the property at the top of the list in record window 24 . If a property is selected for drill down, by double tapping on the touch screen for example, a property detail screen, showing more detailed data from the property record, is displayed.
FIG. 3 illustrates the property detail screen. Property data window 30 displays additional data related to the property, such as whether or not any space is available for lease at the property, square footage, contact information, building details, and the like. Image window 32 displays one or more images of the property and map window 34 displays an icon representing the selected property on a geographic map. Tabs 36 are provide to allow selection of additional detail screens for the same property.
FIG. 4A illustrates a lease detail screen resulting from selecting the Lease tab. This screen shows vacant space in the selected property and various details of the vacant space such as the square footage available, the price, and the leasing agent. Also, recent lease transaction details are shown at the bottom of the screen to allow a potential lessee to better understand the market rate for space in that property.
FIG. 4B illustrates a lease detail screen showing a tenant “stack plan”. This screen shows the identity of tenants, the square footage they are leasing, and the status of the leases (through color coding), such as whether they are moving in, moving out/lease expired, or whether space is available. Note that the tenants are stacked, in a graphical manner by occupied floor and space on that floor. This allows a potential lessee to quickly and accurately understand the various tenant spaces in the building and to identify contiguous floor space.
FIG. 5 illustrates a sale detail screen resulting from selecting the Sale tab of tabs 36 . Various details of the recent sale of the property are shown, such as sales price, down payment, and other details of the transaction. FIG. 6 illustrates a tenant detail screen resulting from selecting the Tenant tab of tabs 36 . This screen is similar to the lease detail screen except that it shows more detail about the tenants such as industry type and lease expiration dates.
FIGS. 7 and 8 illustrate an analytics detail screen resulting from selecting the Analytics tab of tabs 36 . In FIG. 7 , the occupancy rate over time is graphed for the property. In FIG. 8 , which results from scrolling down in FIG. 7 , rental rates for the building, the neighborhood, and the market are graphed over time. Of course, other analytics, such as lease activity, net absorption, local construction activity, comparable sales activity, and occupancy rates, can be graphed versus time or otherwise displayed.
FIG. 9 illustrates a demographic detail screen resulting from selecting the Demographic tab of tabs 36 . Note that, from any of the detail screens shown above, a user can scroll through directly to the same screen for another property by swiping horizontally across the touch screen or through buttons 90 . It can be seen that a user can navigate to a great deal of relevant data very efficiently using a mobile device and the user interface described above.
As noted above, queries can be entered in various ways. FIG. 10 shows an alternative way to enter a query. Query 100 is entered as a street name, without a specific number address. The query results shown in map window 102 represent properties that are along a corridor defined by the street of the query and possibly other parameters, such as dimensions or number of parallel streets away from the street, or distance on either side of the street. In this manner, a user can locate and analyze properties along a corridor, which corresponds more closely to business markets in many cases. Record window 104 shows the results for each property, similar to the description above. Also, navigation can be accomplished in a manner similar to that described above. Of course, filters and sorting options can also be selected and applied to the results. The corridor can be specified through the user interface in various ways. For example a user can draw a single line, or box on the touch screen with one finger, or parallel lines with two fingers. Changing the width of the corridor changes the displayed results.
FIG. 11 shows the application of a Critical Dates filter to a search query or to search results. Selectors 110 can be used to select a Lease Expiration filter. Selecting this filter can map, in a map window, properties that have a lease expiring soon. This filter can be combined with the Critical Date filter to map properties having a lease expiring in a selected date window, for example early in the next year. Selectors 110 can also be used to select an Earliest Lease Sign Date and/or a Latest Lease Sign Date. The filtered results will only include properties having available space in those dates. Of course, a critical date filter can apply to any date related attribute, such as a Sale, Year Built, or Year Renovated. Of course, database 14 can include contract terms, such as lease terms to permit such filtering and display. This data is cross referenced with map data and other real estate data to provide a unique display of properties.
Other filters include Building Rating, Building Size, Energy Star/LEED, Building Class, Space Size, Space Use, Rent/Sq. Footage/Year, Lease Sign Date, Lease Term, Lease Type, Year Built/Renovated, Company/Contact, and the like. These filters can be selected and a particular rating, size or other relevant parameter can be specified through a user interface. Further, when a specific property is selected for display through selection in the map window or the records window, or any other user interface mechanism, a size and/or rating button can be selected and buildings having a same and/or similar size/rating will be displayed. Of course, these filters can be combined with any other filters or search parameters.
FIG. 12 shows an alternative way to enter a query. Query 120 is entered as a submarket/neighborhood name, without a specific street or street number address. The query results shown in map window 122 and record window 124 represent properties that are located in the submarket. Also, submarket boundaries are shown. In this manner, a user can locate and analyze properties in a submarket. Also, navigation can be accomplished in a manner similar to that described above. Of course, filters and sorting options can also be selected and applied to the results. To accommodate this query, database 14 can include boundaries of submarkets and can use the boundaries as a filter on the search query/results. To accomplish a submarket search, a spatial query is applied against a SQL server database to effect a point in polygon (PIP) algorithm against the properties in the search results. The PIP algorithm can be applied when the property is first entered in the database. This approach works well for a search relating to a predefined submarket. Also, the PIP algorithm can be applied at the time of the search. This approach works best for custom polygon searches or other searches of areas that are not predefined in the database.
FIG. 13 illustrates a screen for creating a custom tour. For example a broker may want to select specific properties for physical visit by a client, such as a potential lessee. The custom tour can start with any query, having filters satisfying user criteria for example. The tour can be loaded into a tour application and used on a mobile device to guide and supplement a physical tour of the selected properties. The tour creator can select specific properties from the search results through known user interface actions such as tapping on the touch screen in the map or records window. Once the properties are selected, a Create Tour action can be selected from a drop-down list or other user interface action. The results map of such a selection are illustrated in FIG. 13 in which selected properties are illustrated in map window 132 and in record window 134 . Note that the icons in map window 132 are numbered in order of intended visit to the property on the tour. The order of the properties can be easily changed, by dragging the records displayed in records window 132 for example.
Once the tour is set, the tour creator can load the tour into a tour application to be used by the potential lessee, or other consumer, during the physical tour. The tour application will have only data for the properties in the tour. This creates a subset of the database for use during the tour that will guide and supplement the tour without extraneous data that tends to confuse the tour or lose the focus of the potential lessee or other client. The tour can be published to a web site for download. The reader application and can be branded for the tour creator. Other aspects of navigating and using the reader application can be the same as the app described above.
Additionally, the tour reader application can include various mechanisms for the tour participants to annotate the tour. FIG. 14 illustrates a screen for the tour participants to rate a property on the tour during the tour in real time. Slide bars 142 allow the participant to rate, Amenities, Parking, Condition, Common Areas, On-Site Management and other attributes on a 1-10 scale while they are visiting the property on soon thereafter. Of course, rating can be accomplished for each property on the tour and can include any attribute of the property or neighborhood, market, or the like. Various known user interface elements can be used to allow rating entry, such as radio buttons, number entry, icon selection, speech recognition, text boxes for notes, or the like.
Various analytics can be accomplished during or after the tour. FIG. 15 illustrates a rating comparison screen which presents ratings of several properties on a tour back to the participant for review, editing, and/or decision making FIG. 16 illustrates a screen showing rental rates for properties on the tour for comparison. FIG. 17 illustrates a screen showing rental prices plotted against overall quality determined based on the participant rankings Tours can be updated in real time by applying a query or filter to the data in the tour data set. For example, a tour participant may want to take a second visit to only properties that they rated highly in the property management category. A filter can be applied and the tour updated to include only those properties.
It is known to represent a real estate lease, which is a cash flow over time, as a present value using Discounted Cash Flow analysis (DCF). U.S. Published Patent Application No. 20100063921 discloses methodologies for performing lease-by-lease cash flow analysis to evaluate real estate based securities. The disclosed embodiment uses known analysis techniques and algorithms and presents the results in a way that allows the user of a mobile device to efficiently utilize the information for making lease or purchase decisions. FIG. 18 illustrates a screen showing a cash flow for a property resulting from a search query or from a tour. The cash flow is broken down into various components, such as Base Rent, Consumer Price Index (CPI) Increases, Fixed CPI Steps, and Operating Expenses, all graphed over time in a stacked manner. This allows the user to easily understand the components and magnitude of the cash flow, even on a relatively small screen.
FIG. 19 illustrates a screen showing Lease Discounted Cash Flow (LDCF) information for a property. In window 192 , the screen displays lease information, such as Area of the leased space, Lease Start Date, Lease Term, Base Rent and CPI steps, other expenses, improvements, and the like. Window 194 displays corresponding cash flow metrics calculated from the lease information and other economic assumptions. For example, the cash flow metrics can include Total Cash Flow, Average Annual Cash Flow, Year 1 Cash Flow, Net Present Value, and Net Effective Yearly Rent. Window 196 can display these same metrics in a bar chart, only some of which are shown in FIG. 19 .
FIG. 20 illustrates a LDCF comparison screen showing some of the data and metrics of FIG. 19 for multiple properties selected by the user along with an image and property overview information. The layout of FIG. 20 allows a user to easily compare LDCF information and property information, even on a relatively small display.
The disclosed embodiment is directed to a mobile device, such as a smart phone or a tablet computer, and addresses many limitations of such devices. One problem with such devices is displaying a vast amount of data on a relatively small screen. Also, processing large amounts of data over mobile connections presents bandwidth considerations. For example, if a user were to map all office buildings in Manhattan in New York City on a mobile device, the resulting map window would display thousands of building icons all over-plotting one-another. Many building locations would be hidden under other building locations and would be invisible and inaccessible to the user. The symbolization likely would be so dense that the underlying map would be completely obscured. Also, downloading such a large result set would be detrimental to performance of the mobile application.
To overcome these problems, the embodiment utilizes “over-post reduction” techniques to return a representative set of properties that minimizes map symbol over-plotting. The term “over-post reduction”, as used herein, refers to a technique that reduces the number of geographic locations returned from a data service for display in a real estate map, so that the locations are geographically culled in order to prevent excessive over-plotting on the map. The disclosed methodology ensures that the results are culled in such a way as to preserve a representative geographic distribution of the locations.
The visible viewing area of the map, for example in map window 22 of FIG. 2 , is divided into a number of resources, by process manager 18 of FIG. 1 for example, that can only be used once. These resources are translated into geographic regions, such as quadrangles or other regions, in the data service (latitude/longitude quadrangles), by process manager 18 for example. The SQL statement resulting from a query is modified and designed to return a single result for each quadrangle. The resource size is translated into a quadrangle size using the following information:
The width and height of the map viewing area in points or pixels. The resource size in points or pixels, usually related to the size of an icon placed on the map to represent the geographic location. This resource size can be tuned to increase performance, and to hide or show more data. The map geographic region, which is a range of latitude and longitude.
The quadrangle size contains:
LatitudeDelta—A typical difference in latitude from bottom to top for a resource LongitudeDelta—A typical difference in longitude from left to right for a resource
Potential query results are grouped by the quadrangle which approximates the geographic location of the result. Only the top “n” results in the group are returned. For example, n can equal 1. However, the value of n can be adjusted to return desirable results. An example of a statement resulting from a user query utilizing over post reduction is set forth below:
DECLARE @MaxLon float,—maximum longitude for map window @MinLon float,—minimum longitude for map window @MaxLat float,—maximum latitude for map window @MinLat float—minimum latitude for map window DECLARE @ResourceWidth int—width in points or pixels of resource DECLARE @ScreenWidth int—width in points or pixels of screen DECLARE @ScreenHeight int—height in points or pixels of screen SET @MinLon=−125.0 SET @MaxLon=−67.0 SET @MinLat=30.0 SET @MaxLat=49.0 SET @ResourceWidth=48 SET @ScreenWidth=800 SET @ScreenHeight=600 DECLARE @NumIconsX int DECLARE @NumIconsY int DECLARE @LongitudeDelta decimal(12,7) DECLARE @LatitudeDelta decimal(12,7) SET @NumIconsX=@ScreenWidth/@ResourceWidth—number of 48 pixel icons that can fit across 800×600 map window SET @NumIconsY=@ScreenHeight/@ResourceWidth—number of 48 pixel icons that can fit from top to bottom 800×600 map window SET @LongitudeDelta=(@MaxLon−@MinLon)/@NumIconsX SET @LatitudeDelta=(@MaxLat−@MinLat)/@NumIconsY print @LongitudeDelta print @LatitudeDelta SELECT min(sp.PropertyID) as PropertyID, count(*) as regioncount, FLOOR(sp.Latitude/@LatitudeDelta) as latitudekey, FLOOR (sp.Longitude/@LongitudeDelta) as longitudekey FROM SearchProperty sp with (nolock) WHERE (sp.latitude between @MinLat and @MaxLat) and
(sp.longitude between @MinLon and @MaxLon)
group by FLOOR(sp.Latitude/@LatitudeDelta),
FLOOR (sp.Longitude/@LongitudeDelta)
The basic overpost reduction technique described above can be improved to correct potential user interface anomalies. For example, the basic technique could result in specific properties disappearing when the user zooms on a map window. To minimize this, the embodiment utilizes stepped quadrangle sizes rather than gradually changing quadrangle sizes.
Intuitively, the user expects to see more detail as they zoom the map closer. The size of the quadrangles can be stepped at certain thresholds to guarantee that properties don't disappear. As the zoom level crosses the threshold to the next smaller quadrangle size, each quadrangle is divided into 4 smaller quadrangles. This guarantees that the new smaller quadrangles cannot overlap any boundaries of the old larger quadrangles, and no properties disappear when zooming in.
Also, when a user does a street name search, they intuitively expect to see a graphic representation of all the properties along the street, without the thinning effect caused by the over-post reduction process. To satisfy this, the embodiment automatically increases the over-post granularity by four times when a street search is specified. This allows for a more intuitive user experience as the map more accurately represents the density of properties along the street rather than sparsely dotting them. There is no significant performance degradation since the rest of the map not near the requested street is empty.
Further, the basic algorithm can occasionally create anomalies where individual properties would appear or disappear as the user panned the map at close zoom levels. This can be avoided by not using over post reduction at the default zoom level, This gives users confidence that they can always see all qualifying properties at this zoom level, and eliminates the problem of losing properties when panning at close zoom levels.
In cases where properties are highly concentrated, like the downtown area of major cities, over-post reduction can work too well, and render an unexpectedly small number of results on the map. At some zoom levels the map can look sparsely populated even though the user knows that a large number of properties actually exist. The embodiment displays at least a minimum number of property results at all times after over-post reduction is applied to avoid this problem. The minimum number is configurable but could be set to 250, for example. The search query re-searches multiple times with smaller quadrangle sizes until the minimum is met.
Because both Tenant and Lease Deals frequently produce multiple results for each property shown on the map, situations arise in which as many as 10,000 of these entities were returned for just a few hundred properties. This can significantly degrade performance and exceed the number of results that a user would want to scroll through in the records window. Accordingly, the embodiment can employ an Entity Max of 1000 for these search types. If more than 1000 Tenants or Lease Deals meet the criteria, only 1000 are shown to the user. The algorithm always keeps at least one entity per property (unless there are >1000 properties) and eliminates them based on a sorting criteria that the user selects. This approach keeps the most interesting records at the top of the list.
Similar concepts can be applied to search results other than property mappings. For example, when showing tenant or lease deals for a property, the maximum number of results can also be limited. Both in cases when over-posting is and is not used, if more than, for example 1000 Tenants or Lease Deals meet the criteria, only 1000 can be shown. The algorithm preferably keeps at least one entity per property (unless there are >1000 properties) and eliminates them based on a sorting criteria, like space occupied or lease sign date, giving priority to items with a higher sort value. Over-post processing can be accomplished by client device 12 and/or server device 10 .
The embodiment uses novel query optimization techniques to improve performance. The SQL Server database server caches query execution plans to prevent unnecessary recompilation of common queries. Cached execution plans would sometimes only be effective at certain zoom levels, causing significant performance problems for users doing similar searches at different zoom levels. To avoid this problem, the embodiment adds commented out text, including the zoom level, into the dynamically created queries. This causes the SQL Server to separately cache execution plans based on zoom levels.
Further, multiple dynamic query creation and execution in the database layer and other performance enhancing techniques are used. Search queries are dynamically generated in real time by a single call to a stored procedure. The queries are executed dynamically using sp_executesql, which allows for query plan reuse without having to maintain thousands of separate stored procedures. Separate dynamic SQL templates can be established to handle the different functional and performance needs of different search types. Each template is finely tuned for performance using temp tables, “SELECT INTO” strategy, common table expressions, ROW_NUMBER( ) function, while loops, and query hints as appropriate. Non-property searches use indexed views to increase performance without needing to maintain denormalized property data on non-property search tables.
In order to facilitate query entry, especially on resource constrained mobile devices, the disclosed embodiment enables users to input search text to find zip codes, buildings by name, properties by an address, building parks, shopping centers, cities, submarkets, streets grouped by core based statistics area (CBSA), counties, states, countries, companies, and contacts. Processing of user entered queries can be accomplished at the client device 12 , by app 16 , or at server 10 , by process manager 18 . Before implementing any search, the user input is cleansed. Input is cleansed by removing all leading whitespace, consolidating consecutive whitespace characters into a single space character, and converting the text to all lower cased characters. The indexes of database 14 will only be searched if the cleansed input contains at least three non-whitespace characters. An empty list of result objects are returns when the cleansed input contains fewer than three non-whitespace characters.
In parallel, all indexes of database 14 are searched using an index specific search object. Using regular expressions, the search object validates that the cleansed input is a possible search term. If the term is valid, then a search statement is prepared. The executed statement returns a collection of preferred and non-preferred matched results. Matches are preferred when they fall into the user's preferred market. If the user's current physical location is known, through GPS or the like, then the preferred market primary research market the user is located in. Otherwise the preferred market is based upon the user's preferences. If the current location is unknown and the user hasn't specified a primary market in their preferences, the preferred market can default to the research market that the user's office is located in.
The above-noted indexes are can be specialized full-text search indexes constructed for the following entity types: building names, building park names, city names, company names, contact names, country names, county names, postal codes, zip codes, property addresses, market names, submarket names, shipping center names, region names, state names, or any other parameter that is to be searched.
Once all of the index searches have returned, the preferred results are processed in parallel. The results are processed by converted the matched result into an object that contains a structured text for display. The processed preferred results are subsequently sorted. If the number of preferred results is less than the maximum number of matches to return, the non-preferred matched results are processed and sorted using the same logic as the preferred matches. The processed non-preferred matches are appended to the list of processed and sorted preferred matches. The combined processed search results but no more than the maximum number of matches are returned to the user. In this manner, user queries can be “auto-filled” during entry to suggest queries that are most relevant. For example, if a user begins to enter a query that is known in the market as a street name, the query will be “auto-filled” with the street. However, the same query could be known in another market as a building. In this case, the query would be auto-filled as the building. Suggested queries can be prioritized for display in the following manner, listed from highest priority to lowest priority; Property Address, Geographic Code for Address or Cross Street, Country, Zip Code, City, State, Submarket, Market, Shopping Center Name, Building Park, Building Name, Street Name, Contact, Company, County.
FIG. 21 illustrates a partial query of “Cleveland” being entered into query window 210 . Note the search match window 218 has appeared and has suggested potential queries based on property records in database 18 that are in the local market, Washington, D.C. in this example. With conventional auto-fill, suggestions, such as “Cleveland, Ohio” would be expected. Instead, more helpful, local suggestions, such as “Cleveland Ave.” are provided to the user. The disclosed embodiment thus facilitates intelligent query entry for mobile devices by leveraging the information provided by client device 12 and/or server device 10 thus reducing the need for the user to enter precise and complete queries. Further, queries can be presented based on geographic database subscription limits.
The computing devices disclosed herein include one or more processors designed to process instructions, for example computer readable instructions (i.e., code) stored on a tangible storage device. By processing instructions, the processors perform the steps and functions disclosed herein. Storage devices may be any type of storage device (e.g., an optical storage device, a magnetic storage device, a solid state storage device, etc.), for example a non-transitory storage device. Alternatively, instructions may be stored in one or more remote storage devices, for example storage devices accessed over a network or the internet.
A disclosed embodiment has been described. However, the invention is not limited thereto and includes all variations and equivalents as would be known to one of skill in the art and within the scope of the appended claims.
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A system and method for managing real estate data using a mobile device, such as a tablet computer. The data is displayed in a manner that facilitates quick analysis suing a mobile device. User interfaces, processing, and other features provide a mobile user with information required to make intelligent decisions on real estate transactions. A tour can be constructed based on a subset of data returned as a result of a database query.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a self-service terminal (SST). In particular, the invention relates to a public access self-service terminal such as an automated teller machine (ATM) or a non-cash kiosk.
[0002] It is well known that ATMs are commonly used as a convenient source of cash and other financial transactions. Some users of ATMs desire a quick cash dispense transaction (sometimes referred to as fast cash) without viewing any promotional material (such as advertisements or marketing information) or other services (such as other transactions). Other users, however, are willing to view promotional material and/or services on ATMs depending on certain factors, such as whether they are in a hurry, whether they are interested in the type of product or service that is being promoted, or such like. If promotional material or services are presented to users at inappropriate times, or if an ATM transaction is lengthened because of presenting other services or soliciting some input from the user, then the user may be annoyed by the delay and as a result may be unsatisfied with the ATM transaction.
SUMMARY OF THE INVENTION
[0003] It is among the objects of an embodiment of the present invention to obviate or mitigate one or more of the above disadvantages or other disadvantages associated with prior art self-service terminals.
[0004] According to a first aspect of the present invention there is provided a self-service terminal having a user interface for interacting with a user, characterized in that the terminal includes sensing means for sensing physiological data associated with a user, analyzing means for analyzing the physiological data to deduce the user's emotional state, and control means responsive to the analyzing means for adapting the terminal's interaction with the user in response to the user's emotional state.
[0005] The sensing means may be implemented using a contact device, but more preferably, using a non-contact device.
[0006] Where a contact device is used, the sensing means may comprise a touch area incorporating sensors for determining the user's skin temperature, pulse rate, blood pressure, skin conductivity, and such like physiological data. A suitable touch area may be implemented by a device developed by IBM (trade mark) and called an “emotion mouse”.
[0007] Where a non-contact device is used, and the terminal includes speech input, the sensing means may be implemented by a voice monitoring system for detecting changes in a user's voice. Additionally or alternatively, the sensing means may be implemented by facial recognition to detect changes in the user's facial appearance during a transaction. The sensing means may be implemented using an iris camera for imaging the user's iris and for detecting changes within the iris, such as changes to blood vessels, and such like. The sensing means may be implemented by a gesture recognition system.
[0008] The analyzing means may be implemented by any convenient algorithm for deducing a person's emotional state from physiological measurements taken from the person. An overview of such algorithms is given in chapter 6 of “Affective Computing” by Rosalind W Picard, MIT Press, 1997, ISBN 0-262-16170-2.
[0009] The control means may be implemented by a control application executing on the terminal. The control application may present a user with a sequence of screens to guide the user through a transaction. The control application may determine which screens are to be shown to the user in response to the user's emotional state as deduced by the analyzing algorithm.
[0010] The term “screen” is used herein to denote the graphics, text, controls (such as menu options), and such like, that are displayed on an SST display; the term “screen” as used herein does not refer to the hardware (for example, the LCD, CRT, or touchscreen) that displays the graphics, text, controls, and such like. Typically, when a transaction is being entered at an SST, a series of screens are presented in succession on the SST display. For example, a first screen may request a user to insert a card, a second screen may invite the user to enter his/her personal identification number (PIN), a third screen may invite the user to select a transaction, and so on.
[0011] By virtue of this aspect of the invention, the terminal is able to sense physiological data from a user during a transaction, analyze the data, and determine what to present to the user to comply with the user's emotional state. For example, the terminal may determine what transaction options to present, whether to present advertising or marketing material, if advertising is to be presented then what advertisements to present, for how long the advertisement is to last, at what point in the transaction the advertisement is to be shown, and such like.
[0012] Thus, the user's experience at the SST can be improved by personalizing a transaction to the user's emotional state. For example, if a user feels insecure then the SST may:
[0013] highlight to the user alternative SST locations at which they user may feel more secure;
[0014] display a message regarding privacy and trust to reassure the user that the transaction is secure and that the transaction provider is one that the user can trust to keep user information private;
[0015] give the user an option of more time to select a transaction option.
[0016] The SST can improve the transaction provider's marketing and advertising efficiency by targeting advertisements that are known to be more effective for a particular emotional state. For example, if the user is in a happy mood and relaxed then the user might be receptive to advertising and the SST may:
[0017] present humorous advertisements, and/or
[0018] have a longer transaction sequence to provide more advertising time.
[0019] The SST may record a user's emotional experience so that future transactions conducted by that user are automatically personalized. For example, if the user is not in a relaxed mood then the user might be irritated by advertising and the SST may:
[0020] adapt the transaction to have no advertising during that transaction, or
[0021] go to a customized quick transaction flow for that user the next time they use the SST.
[0022] If the SST detects particular emotional states of users, then the SST may invoke extra security measures to improve security for both the users and the SST provider. For example, if the user was detected as being under a great deal of stress then this may indicate that the user is executing a transaction under duress, or the user may be using a stolen transaction token (such as a magnetic stripe card). These extreme types of emotional states could trigger additional security measures at the SST, such as:
[0023] more security photographs being taken; and/or
[0024] security information being requested from the user.
[0025] In one embodiment the SST is an ATM.
[0026] According to a second aspect of the present invention there is provided a method of operating a self-service terminal, the method comprising the steps of: sensing physiological data associated with a user of the terminal, analyzing the physiological data to deduce the user's emotional state, and adapting the terminal's interaction with the user in response to the user's emotional state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] These and other aspects of the present invention will be apparent from the following specific description, given by way of example, with reference to the accompanying drawings, in which:
[0028] [0028]FIG. 1 is a block diagram of a self-service terminal according to one embodiment of the present invention;
[0029] [0029]FIG. 2 is a block diagram of a part (the controller) of the terminal of FIG. 1;
[0030] [0030]FIGS. 3A to 3 F illustrate a sequence of screens presented to one user of the terminal of FIG. 1; and
[0031] [0031]FIGS. 4A to 4 H illustrate a sequence of screens presented to another user of the terminal of FIG. 1.
DETAILED DESCRIPTION
[0032] Reference is now made to FIG. 1, which illustrates an SST 10 in the form of an ATM being operated by a user 12 .
[0033] The ATM 10 includes a user interface 14 for outputting information to a user and for allowing a user to input information. The ATM 10 also includes sensing means 16 in the form of a camera module 18 (that includes facial recognition software), a touch plate module 20 (implemented by an “emotion mouse”), and a microphone module 22 (that includes voice recognition software).
[0034] The user interface 14 is a molded fascia incorporating: a display module 30 , an encrypting keypad module 32 , and a plurality of slots aligned with modules located behind the fascia. The slots include a card entry/exit slot (not shown) that aligns with a magnetic card reader/writer (MCRW) module 36 , a printer slot (not shown) that aligns with a printer module 38 , and a cash dispense slot (not shown) that aligns with a cash dispense module 40 .
[0035] The ATM 10 also includes an internal journal printer module 50 for creating a record of all transactions executed by the ATM 10 , an ATM controller module 52 for controlling the operation of the various modules ( 18 to 50 ), and a network connection module 54 for communicating with a remote transaction host (not shown) for authorizing transactions. All of the modules ( 18 to 54 ) within the ATM 12 are interconnected by an internal bus 56 for securely conveying data.
[0036] The ATM controller module 52 is shown in more detail in FIG. 2. The controller 52 comprises a BIOS 60 stored in non-volatile memory, a microprocessor 62 , associated main memory 64 , and storage space 66 in the form of a magnetic disk drive.
[0037] In use, the ATM 12 loads an operating system kernel 70 , an ATM application program 72 , and a data analyzing program 74 into the main memory 64 .
[0038] The ATM application program 72 is used to control the operation of the ATM 12 . In particular, the ATM application program 72 : provides the sequence of screens used in each transaction (referred to as the application flow); monitors the condition of each module within the ATM (state of health monitoring); and interfaces with the analyzing program 74 .
[0039] The analyzing program 74 implements a discriminant function analysis model for analyzing data received from the sensor modules 18 to 22 ; however, any other convenient analyzing program may be used. The analyzing program 74 processes data received from one or more of the sensor modules (camera 18 , touch plate 20 , or microphone 22 ) to deduce the emotional state of the user 12 .
[0040] The analyzing program 74 selects an emotion category that is the closest match to the user's emotional state, and outputs a code representing this category to the ATM application program 72 . In this embodiment, the categories are: anger, hurriedness, fear, happiness, sadness, and surprise.
[0041] The ATM application program 72 receives this code and adapts the transaction flow according to the emotional state represented by this code. This is implemented by the ATM application program 72 accessing a stored look-up table (not shown) having an index entry for each code. Each code in the look-up table has a unique transaction flow associated with it.
[0042] An example of a typical transaction at the ATM 10 will now be described with reference to FIGS. 3A to 3 F, which illustrate the sequence of screens presented to the user 12 .
[0043] When the user 12 approaches the ATM 10 he is presented with a welcome screen 80 a (FIG. 3A) on display 30 inviting him to insert his card. After inserting his card, the user 12 is presented with a screen 80 b (FIG. 3B) inviting him to enter his PIN, and the ATM application program 72 activates the sensors 18 to 22 to capture physiological data about the user 12 .
[0044] The ATM application receives data from the sensors 18 to 22 and conveys this data to the data analyzing program 74 . Data analyzing program 74 processes the received data, deduces the user's emotional state from the data, generates a category code representing the user's emotional state, and conveys this code to the ATM application program 72 . The ATM application program 72 accesses the look-up table (not shown) using the category code received from the data analyzing program 74 to determine what sequence of screens should be presented to the user 12 . In this example, the user's state is hurriedness, so the sequence of screens is that for the shortest possible transaction time.
[0045] The ATM application program 72 then presents the user 12 with a screen 80 c (FIG. 3C) listing transaction options available. After the user 12 has selected the withdraw cash option, the ATM application 72 presents the user with a screen 80 d (FIG. 3D) indicating cash amounts available. Once the user has selected a cash amount, the ATM application authorizes the transaction, presents a screen 80 e (FIG. 3E) inviting the user to remove his card, then a screen 80 f (FIG. 3F) inviting the user to remove the requested cash.
[0046] An example of a typical transaction at the ATM 10 will now be described with reference to FIGS. 4A to 4 H, which illustrate the sequence of screens presented to another user (or the same user as for FIGS. 3A to 3 F but in a different emotional state).
[0047] When the user approaches the ATM 10 he is presented with a welcome screen 82 a (FIG. 4A) on display 30 inviting him to insert his card. After inserting his card, the user is presented with a screen 82 b (FIG. 4B) inviting him to enter his PIN, and the ATM application program 72 activates the sensors 18 to 22 to capture physiological data about the user.
[0048] As in the previous example, the ATM application 72 receives data from the sensors 18 to 22 and conveys this data to the data analyzing program 74 . Data analyzing program 74 processes the received data, deduces the user's emotional state from the data, generates a category code representing the user's emotional state, and conveys this code to the ATM application program 72 . The ATM application program 72 accesses its look-up table (not shown) using the category code received from the data analyzing program 74 to determine what sequence of screens should be presented to the user. In this example, the user's state is happiness, so the sequence of screens includes an advertisement for a holiday, and promotional material for a loan.
[0049] The ATM application program 72 then presents the user with a screen 82 c (FIG. 4C) listing transaction options available. After the user has selected the withdraw cash option, the ATM application 72 presents the user with a screen 82 d (FIG. 4D) indicating cash amounts available.
[0050] Once the user has selected a cash amount, the ATM application 72 authorizes the transaction, and presents the user with a screen 82 e (FIG. 4E) incorporating a video 84 (in MPEG format) advertising a holiday, the screen 82 e also includes text 86 informing the user that the requested transaction is being authorized.
[0051] Once the video (which lasts approximately four seconds) has finished, the ATM application 72 then presents the user with a screen 82 f (FIG. 4F) incorporating promotional material 88 for a loan.
[0052] The ATM application 72 then presents a screen 82 g (FIG. 4G) inviting the user to remove his card, and once the card has been removed, a screen 82 h (FIG. 4H) inviting the user to remove the requested cash.
[0053] It will be appreciated that this embodiment has the advantage that a user is presented with a transaction sequence that is most likely to fulfil the user's expectations by matching a transaction to the user's emotional state.
[0054] Various modifications may be made to the above described embodiment within the scope of the invention, for example, in other embodiments, the user may be asked to touch the touch plate 20 at the beginning of the transaction so that the touch plate can collect physiological data from the user's hand. In other embodiments, multiple algorithms may be used to implement the analyzing program 74 , one for each sensor module 18 to 22 . In other embodiments, different sensors may be used. In other embodiments, the touch plate sensor may be implemented on the keys of the encrypting keypad so that physiological measurements can be taken while the user is entering his PIN or other transaction details. In other embodiments, the user's emotional state may be continually monitored during the transaction flow so that the transaction flow may be changed at any point in response to the user's emotional state; for example, an advertisement may be stopped if a user's emotional state changes from being happy or relaxed to being unhappy or angry. In other embodiments, different emotional states may be categorized than those described in the above embodiment.
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A self-service terminal ( 10 ) having a user interface ( 14 ) for interacting with a user ( 12 ) is described. The terminal ( 10 ) includes sensing means ( 18, 20, or 22 ) for sensing physiological data associated with a user, analyzing means ( 74 ) for analyzing the physiological data to deduce the user's emotional state, and control means ( 72 ) responsive to the analyzing means ( 74 ) for adapting the terminal's interaction with the user in response to the user's emotional state. A method of operating a self-service terminal is also described.
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CROSS REFERENCE TO A RELATED APPLICATION
This application is a National Stage Application of International Application Number PCT/CN2014/071086, filed Jan. 22, 2014; which claims priority to Chinese Patent Application No. 201310117087.6, filed Apr. 3, 2013; both of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to construction equipment for mine shafts and drifts, in particular to a guide rail rope deflection inhibiting mechanism and a method for a parallel flexible cable suspension system, which are applicable to construction of ultra-deep vertical shafts.
BACKGROUND OF THE INVENTION
As shallow and semi-deep mineral resources are depleted gradually in China, exploiting deep resources has become an inevitable choice for ensuring sustainable development of the national economy. Therefore, it is imperative to excavate ultra-deep vertical shafts, and that mission brings higher requirements for safe transportation of personnel and materials. At present, most guide frames for deep vertical shaft construction employ two suspension ropes also as guide rail ropes, which are pre-tensioned by the dead weight of the guide frame. Such a system belongs to a typical parallel flexible cable suspension guiding system, which is mainly designed to provide guiding function for the movement of a lifting container. If the pretension of the guide rail rope of the suspension guiding system is too small, the lifting container will have a severe deflection or even turn over when it runs along the guide rail rope, which endangers life safety of the construction workers. Therefore, the “Specifications for Construction and Acceptance of Mine Shaft and Drift” specifies that the tension force per 100 m steel wire rope shall not be smaller than 1 ton when a steel-rope guide is used; in addition, the “Safety Regulations in Coal Mine” specifies that the safety factor of a cable guide shall not be lower than 6. For an ultra-deep vertical shaft, the pretension must be increased as the length of the guide rail rope is increased. However, that specification can not be met solely by means of the dead weight of the guide frame; otherwise the deflection of the lifting container will be very severe; even though the pretension meets the requirement, the steel wire rope can't be selected among standard products because of the extremely high pretension, under the constraints of tensile strength and safety factor. In summary, it is difficult to inhibit the deflection of guide rail rope in a parallel flexible cable suspension system, which brings a severe risk to the safety of construction of ultra-deep vertical shafts.
SUMMARY OF THE INVENTION
Object of the invention: an object of the present invention is to provide a guide rail rope deflection inhibiting mechanism and a method for a parallel flexible cable suspension system, in order to solve a problem that it is difficult to inhibit the guide rail rope deflection in existing parallel flexible cable suspension guiding systems in construction of ultra-deep vertical shafts.
To solve the technical problem described above, the following technical solutions are employed by the present invention:
A guide rail rope deflection inhibiting mechanism for a parallel flexible cable suspension system, comprising a ‘T’-shaped mounting support, a rotary frame, a hydraulic supporting rod and a chuck, wherein the ‘T’-shaped mounting support comprises a longitudinal supporting rod and a transverse supporting rod, the longitudinal supporting rod is fixed on the shaft wall, and one end of the transverse supporting rod is fixed to the center of the longitudinal supporting rod; the hydraulic supporting rod comprises an upper hydraulic supporting rod and a lower hydraulic supporting rod, one end of the upper hydraulic supporting rod is hinged to the upper end of the longitudinal supporting rod, and one end of the lower hydraulic supporting rod is hinged to the lower end of the longitudinal supporting rod; the rotary frame comprises an upper ‘Y’-shaped bracket and a lower ‘Y’-shaped bracket, one end of the upper ‘Y’-shaped bracket is hinged to the other end of the upper hydraulic supporting rod, one end of the lower ‘Y’-shaped bracket is hinged to the other end of the lower hydraulic supporting rod, and the other end of the upper ‘Y’-shaped bracket is fixed to the other end of the lower ‘Y’-shaped bracket, and both of the ends are hinged to the other end of the transverse supporting rod; the chuck comprises an upper chuck and a lower chuck, the upper chuck is fixed to a third end of the upper ‘Y’-shaped bracket, and the lower chuck is fixed to a third end of the lower ‘Y’-shaped bracket;
When the rotary frame rotates around the other end of the transverse supporting rod to a position where the lower chuck is in a horizontal state, the upper chuck will be in an up-tilting state; when the rotary frame rotates around the other end of the transverse supporting rod to a position where the upper chuck is in a horizontal state, the lower chuck will be in a down-tilting state.
In the guide rail rope deflection inhibiting mechanism according to the present invention, furthermore, said upper ‘Y’-shaped bracket and said lower ‘Y’-shaped bracket have the same structure, the third end of the upper ‘Y’-shaped bracket and the third end of the lower ‘Y’-shaped bracket are provided with a hollow steel part respectively, the hollow steel part has a bolt hole, and a fastening bolt is arranged in the bolt hole; both the upper chuck and the lower chuck comprise a ‘V’-shaped chuck and a round steel part, the ‘V’-shaped chuck has a snap groove that can embrace the guide rail rope, one end of the round steel part is fixed on the ‘V’-shaped chuck, and the other end of the round steel part extends into the tube of the hollow steel part and is fixed by a fastening bolt.
A guide rail rope deflection inhibiting method for a parallel flexible cable suspension system, wherein, every two guide rail rope deflection inhibiting mechanisms described above are arranged into a group, and at least two groups of guide rail rope deflection inhibiting mechanisms are arranged on the shaft wall in a vertical direction;
When the lifting container is to run downward, the rotary frame in the guide rail rope deflection inhibiting mechanism is rotated to a position where the lower chuck is in a horizontal state, and the guide rail rope is secured by the lower chuck; at this point, the upper chuck is in a tilting state that permits the guide frame to pass through it; when the guide frame passes through the guide rail rope deflection inhibiting mechanism, it will push the lower chuck to retract and deflect downward gradually, and thereby the rotary frame will be driven to rotate to a position where the upper chuck is in a horizontal state, and the guide rail rope will be secured by the upper chuck;
When the lifting container is to run upward, the rotary frame in the guide rail rope deflection inhibiting mechanism is rotated to a position where the upper chuck is in a horizontal state, and the guide rail rope is secured by the upper chuck; at this point, the lower chuck is in a tilting state that permits the guide frame to pass through it; when the guide frame passes through the guide rail rope deflection inhibiting mechanism, it will push the upper chuck to retract and deflect upward gradually, and thereby the rotary frame will be driven to rotate to a position where the lower chuck is in a horizontal state, and the guide rail rope will be secured by the lower chuck.
In the guide rail rope deflection inhibiting method according to the present invention, furthermore, the spacing between two adjacent groups of guide rail rope deflection inhibiting mechanisms is 5-20 m.
The present invention has the following advantages:
(1) By adopting the guide rail rope deflection inhibiting mechanism according to the present invention and arranging it on the shaft wall reasonably, on the premise that a guide frame can slide smoothly, the chuck constrains a part of degrees of freedom of a guide rail rope to inhibit guide rail rope deflection, so that the running stability and the safety of a lifting container are improved;
(2) The guide rail rope deflection inhibiting mechanism according to the present invention is a self-actuated pure mechanical structure and does not need electric power or hydraulic drive; thus, it can effectively save cables and space in the shaft;
(3) The chucks only semi-embrace the guide rail rope; therefore, they can be installed synchronously in the construction process, which is to say, it is unnecessary to lift the hanging scaffold to the ground and renovate it; thus, the construction time can be saved;
(4) The hydraulic supporting rod has a damping function itself; thus, compared with a unit that has a single fork and is actuated by a spring, the present mechanism is more stable in transition and the shock on the guide rail rope is smaller;
(5) The guide rail rope deflection inhibiting mechanism according to the present invention is simple in structure, easy to manufacture and install, has reliable performance, and is easy to disassemble and reassemble.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic structural diagram of the guide rail rope deflection inhibiting mechanism for a parallel flexible cable suspension system according to the present invention;
FIG. 2 is a schematic structural diagram of the connection between the rotary frame and the chucks;
FIG. 3 is a schematic layout diagram of the guide rail rope deflection inhibiting mechanism in the guide rail rope deflection inhibiting method for a parallel flexible cable suspension system in the present invention;
FIG. 4 is a schematic diagram illustrating a state in which the moment of resistance is negative during the movement of the deflection inhibiting mechanism;
FIG. 5 is a schematic diagram illustrating a state in which the moment of resistance is zero during the movement of the deflection inhibiting mechanism;
FIG. 6 is a schematic diagram illustrating a state in which the moment of resistance is positive during the movement of the deflection inhibiting mechanism.
Among the figures: 1 —‘T’-shaped mounting support, 2 —rotary frame, 3 —hydraulic supporting rod, 4 —chuck, 5 —guide rail rope, 6 —guide frame, 7 —lifting container, 8 —shaft wall; 2 - 1 —upper ‘Y’-shaped bracket, 2 - 2 —lower ‘Y’-shaped bracket, 2 - 3 —hollow steel part, 2 - 4 —fastening bolt, 2 - 5 —bolt hole; 3 - 1 —upper hydraulic supporting rod, 3 - 2 —lower hydraulic supporting rod; 4 - 1 —upper chuck, 4 - 2 —lower chuck, 4 - 3 —‘V’-shaped chuck, 4 - 4 —round steel part.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Hereunder the present invention will be further detailed with reference to the accompanying drawings.
As shown in FIG. 1 and FIG. 2 , the guide rail rope deflection inhibiting mechanism for a parallel flexible cable suspension system according to the present invention comprises a ‘T’-shaped mounting support 1 , a rotary frame 2 , a hydraulic supporting rod 3 and a chuck 4 .
The ‘T’-shaped mounting support 1 comprises a longitudinal supporting rod and a transverse supporting rod, the longitudinal supporting rod is fixed on the shaft wall 8 , and one end of the transverse supporting rod is fixed to the center of the longitudinal supporting rod. The hydraulic supporting rod 3 comprises an upper hydraulic supporting rod 3 - 1 and a lower hydraulic supporting rod 3 - 2 , one end of the upper hydraulic supporting rod 3 - 1 is hinged to the upper end (end A in the figures) of the longitudinal supporting rod, and one end of the lower hydraulic supporting rod 3 - 2 is hinged to the lower end (end B in the figures) of the longitudinal supporting rod. The rotary frame 2 comprises an upper ‘Y’-shaped bracket 2 - 1 and a lower ‘Y’-shaped bracket 2 - 2 , and the upper ‘Y’-shaped bracket 2 - 1 and lower ‘Y’-shaped bracket 2 - 2 are in the same structure. One end (end C in the figures) of the upper ‘Y’-shaped bracket 2 - 1 is hinged to the other end of the upper hydraulic supporting rod 3 - 1 , one end (end D in the figures) of the lower ‘Y’-shaped bracket 2 - 2 is hinged to the other end of the lower hydraulic supporting rod 3 - 2 , the other end of the upper ‘Y’-shaped bracket 2 - 1 is fixed to the other end of the lower ‘Y’-shaped bracket 2 - 2 and hinged to the other end (end E in the figures) of the transverse supporting rod; a third end of the upper ‘Y’-shaped bracket 2 - 1 and a third end of the lower ‘Y’-shaped bracket 2 - 2 are provided with a hollow steel part 2 - 3 respectively, the hollow steel part 2 - 3 has a bolt hole 2 - 5 , and a fastening bolt 2 - 4 is arranged in the bolt hole 2 - 5 . The chuck 4 comprises an upper chuck 4 - 1 and a lower chuck 4 - 2 , and both the upper chuck 4 - 1 and the lower chuck 4 - 2 comprise a a ‘V’-shaped chuck 4 - 3 and a round steel part 4 - 4 , the ‘V’-shaped chuck 4 - 3 is arranged with a snap groove that can embrace the guide rail rope 5 , one end of the round steel part 4 - 4 is fixed to the ‘V’-shaped chuck 4 - 3 , and the other end of the round steel part 4 - 4 extends into the tube of the hollow steel part 2 - 3 and is fixed by a fastening bolt 2 - 4 , and thereby the upper chuck 4 - 1 and lower chuck 4 - 2 are fixed to the third end of the upper ‘Y’-shaped bracket 2 - 1 and the third end of the lower ‘Y’-shaped bracket 2 - 2 respectively, so that the rotary frame 2 and the chuck 4 are connected together. During use, the length of the round steel part 4 - 4 extending into the hollow steel tube 2 - 3 can be adjusted to regulate the extension length of the upper chuck 4 - 1 and the lower chuck 4 - 2 , so as to secure the guide rail rope 5 .
As shown in FIG. 4 , when the rotary frame 2 rotates around the other end of the transverse supporting rod to a position where the lower chuck 4 - 2 is in a horizontal state, the upper chuck 4 - 1 will be in an up-tilting state. At this point, both the upper hydraulic supporting rod 3 - 1 and the lower hydraulic supporting rod 3 - 2 are in maximum extension state; in addition, since the hydraulic supporting rod 3 provides persistent and steady pushing force, the moment of resistance to the other end of the transverse supporting rod of the ‘T’-shaped mounting support 1 is negative (here, the moment in a counter-clockwise direction is defined as positive); therefore, the rotary frame 2 cannot rotate, and the guide rail rope deflection inhibiting mechanism is in a stable state. As shown in FIG. 5 , when the rotary frame 2 rotates around the other end of the transverse supporting rod to a position where the upper end of the longitudinal supporting rod, one end of the upper ‘Y’-shaped bracket 2 - 1 , and the other end of the ‘Y’-shaped bracket 2 - 1 are in the same line, the lower end of the longitudinal supporting rod, one end of the lower ‘Y’-shaped bracket 2 - 2 , and the other end of the lower ‘Y’-shaped bracket 2 - 2 will be also in the same line. At this point, the moment of resistance of the hydraulic supporting rod 3 to the other end of the transverse supporting rod of the ‘T’-shaped mounting support 1 is zero. As shown in FIG. 6 , when the rotary frame 2 rotates around the other end of the transverse supporting rod to a position where the upper chuck 4 - 1 is in a horizontal state, the lower chuck 4 - 2 will be in an up-tilting state. At this point, both the upper hydraulic supporting rod 3 - 1 and the lower hydraulic supporting rod 3 - 2 are in maximum extension state; in addition, since the hydraulic supporting rod 3 provides persistent and steady pushing force, the moment of resistance to the other end of the transverse supporting rod of the ‘T’-shaped mounting support 1 is positive; therefore, the rotary frame 2 cannot rotate, and the guide rail rope deflection inhibiting mechanism is in a stable state.
As shown in FIG. 3 , the guide rail rope deflection inhibiting method for a parallel flexible cable suspension system according to the present invention is characterized in that every two guide rail rope deflection inhibiting mechanisms are arranged into a group, and at least two groups of the guide rail rope deflection inhibiting mechanisms are arranged on the shaft wall 8 in a vertical direction. In this embodiment, two groups of guide rail rope deflection inhibiting mechanisms are provided, and they are arranged on the lower part (or middle part) of the guide rail rope 5 , where the lateral rigidity is lower; the spacing between the two groups of guide rail rope deflection inhibiting mechanisms is 5-20 m.
When the lifting container 7 is to run downward, the rotary frames 2 of the two groups of guide rail rope deflection inhibiting mechanisms are rotated to a position where the lower chucks 4 - 2 are in a horizontal state, and the guide rail rope 5 are secured by the lower chucks 4 - 2 of the two groups of guide rail rope deflection inhibiting mechanisms; at this point, the upper chucks 4 - 1 of the two groups of guide rail rope deflection inhibiting mechanisms are in a tilting state that permits the guide frame 6 to pass through.
When the guide frame 6 moves downward and comes into contact with the lower chuck 4 - 2 of the first group of guide rail rope deflection inhibiting mechanisms, the guide frame 6 will overcome the moment of resistance produced by the hydraulic supporting rod 3 of the first group of guide rail rope deflection inhibiting mechanisms by gravity, and push the lower chuck 4 - 2 of the first group of guide rail rope deflection inhibiting mechanisms to retract and deflect downward gradually, and thereby drive the rotary frame 2 of the first group of guide rail rope deflection inhibiting mechanisms to rotate; when the guide frame 6 is separated from the lower chuck 4 - 2 of the first group of guide rail rope deflection inhibiting mechanisms, the rotary frame 2 of the first group of guide rail rope deflection inhibiting mechanisms will be rotated to a position where the upper chuck 4 - 1 is in horizontal state, and the guide rail rope 5 will be secured by the upper chuck 4 - 1 of the first group of guide rail rope deflection inhibiting mechanisms. In that process, the guide frame 6 runs downward smoothly, and passes through the first group of guide rail rope deflection inhibiting mechanisms.
When the guide frame 6 moves downward to a position between the first group of guide rail rope deflection inhibiting mechanisms and the second group of guide rail rope deflection inhibiting mechanisms, the guide rail rope 5 is secured by the upper chuck 4 - 1 of the first group of guide rail rope deflection inhibiting mechanisms and the lower chuck 4 - 2 of the second group of guide rail rope deflection inhibiting mechanisms.
When the guide frame 6 moves downward and comes into contact with the lower chuck 4 - 2 of the second group of guide rail rope deflection inhibiting mechanisms, the guide frame 6 will overcome the moment of resistance produced by the hydraulic supporting rod 3 of the second group of guide rail rope deflection inhibiting mechanisms by gravity, and will push the lower chuck 4 - 2 of the second group of guide rail rope deflection inhibiting mechanisms to retract and deflect downward gradually, and thereby drive the rotary frame 2 of the second group of guide rail rope deflection inhibiting mechanisms to rotate; when the guide frame 6 is separated from the lower chuck 4 - 2 of the second group of guide rail rope deflection inhibiting mechanisms, the rotary frame 2 of the second group of guide rail rope deflection inhibiting mechanisms will be rotated to a position where the upper chuck 4 - 1 is in horizontal state, and the guide rail rope 5 will be secured by the upper chucks 4 - 1 of the second group of guide rail rope deflection inhibiting mechanisms. In that process, the guide frame 6 runs downward smoothly, and passes through the second group of guide rail rope deflection inhibiting mechanisms.
After the guide frame 6 passes through the second group of guide rail rope deflection inhibiting mechanisms, the guide rail rope 5 will be secured by the upper chucks 4 - 1 of the two groups of guide rail rope deflection inhibiting mechanisms.
Likewise, when the lifting container 7 runs upward, the rotary frames 2 of the two groups of guide rail rope deflection inhibiting mechanisms are rotated to a position where the upper chucks 4 - 1 are in a horizontal state, and the guide rail rope 5 is secured by the upper chucks 4 - 1 of the two groups of guide rail rope deflection inhibiting mechanisms; at this point, the lower chucks 4 - 1 of the two groups of guide rail rope deflection inhibiting mechanisms are in a tilting state that permits the guide frame 6 to pass through.
When the guide frame 6 moves upward and comes into contact with the upper chuck 4 - 1 of the second group of guide rail rope deflection inhibiting mechanisms, the guide frame 6 will overcome the moment of resistance produced by the hydraulic supporting rod 3 of the second group of guide rail rope deflection inhibiting mechanisms by the upward pushing force provided by the lifting container 7 , and will push the upper chuck 4 - 1 of the second group of guide rail rope deflection inhibiting mechanisms to retract and deflect upward gradually, and thereby drive the rotary frame 2 of the second group of guide rail rope deflection inhibiting mechanisms to rotate; when the guide frame 6 is separated from the upper chuck 4 - 1 of the second group of guide rail rope deflection inhibiting mechanisms, the rotary frame 2 of the second group of guide rail rope deflection inhibiting mechanisms will be rotated to a position where the lower chuck 4 - 2 is in horizontal state, and the guide rail rope 5 will be secured by the lower chuck 4 - 2 of the second group of guide rail rope deflection inhibiting mechanisms. In that process, the guide frame 6 runs upward smoothly, and passes through the second group of guide rail rope deflection inhibiting mechanisms.
When the guide frame 6 moves upward to a position between the second group of guide rail rope deflection inhibiting mechanisms and the first group of guide rail rope deflection inhibiting mechanisms, the guide rail rope 5 will be secured by the lower chuck 4 - 2 of the second group of guide rail rope deflection inhibiting mechanisms and the upper chuck 4 - 1 of the first group of guide rail rope deflection inhibiting mechanisms.
When the guide frame 6 moves upward and comes into contact with the upper chuck 4 - 1 of the first group of guide rail rope deflection inhibiting mechanisms, the guide frame 6 will overcome the moment of resistance produced by the hydraulic supporting rod 3 of the first group of guide rail rope deflection inhibiting mechanisms by the upward pushing force provided by the lifting container 7 , and push the upper chuck 4 - 1 of the first group of guide rail rope deflection inhibiting mechanisms to retract and deflect upward gradually, and thereby drive the rotary frame 2 of the first group of guide rail rope deflection inhibiting mechanisms to rotate; when the guide frame 6 is separated from the upper chuck 4 - 2 of the first group of guide rail rope deflection inhibiting mechanisms, the rotary frame 2 of the first group of guide rail rope deflection inhibiting mechanisms will rotate to a position where the lower chuck 4 - 1 is in horizontal state, and the guide rail rope 5 will be secured by the lower chuck 4 - 2 of the first group of guide rail rope deflection inhibiting mechanisms. In that process, the guide frame 6 runs upward smoothly, and passes through the first group of guide rail rope deflection inhibiting mechanisms.
After the guide frame 6 passes through the first group of guide rail rope deflection inhibiting mechanisms, the guide rail rope 5 will be secured by the lower chucks 4 - 2 of the two groups of guide rail rope deflection inhibiting mechanisms.
While the present invention has been illustrated and described with reference to some preferred embodiments, the present invention is not limited to these. Those skilled in the art should recognize that various variations and modifications can be made without departing from the spirit and scope of the present invention. All of such variations and modifications shall be deemed as falling into the protection scope of the present invention.
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A guide rail rope deflection inhibition mechanism and method for a parallel soft cable suspension system in ultradeep vertical shaft construction. The guide rail rope deflection inhibition mechanism comprises a T-shaped installation support base, a rotating frame, a hydraulic support rod, and a chuck. The T-shaped installation support base comprises a vertical support rod and a horizontal support rod. The hydraulic support rod comprises an upper hydraulic support rod and a lower hydraulic support rod. The rotating frame comprises an upper Y-shaped frame and a lower Y-shaped frame. The chuck comprises an upper chuck and a lower chuck. The guide rail rope deflection inhibition method treats two guide rail rope deflection inhibition mechanisms as one group, and arranges at least two groups along the vertical direction on the shaft wall. While guaranteeing the smooth sliding of a direction guiding frame, the freedom of the guide rail rope part is restrained by the chuck, thereby enhancing the stability and safety of hoisting containers.
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BACKGROUND OF THE INVENTION
1. The Field of the Invention
This invention relates to game apparatus and more specifically to that class utilizing hoops and hoop propelling devices.
2. Description of the Prior Art
The prior art abounds with hoops and hoop propelling devices. U.S. Pat. No. 2,562,522 issued on July 31, 1951 to C. P. Boyd teaches a pair of roller-like devices in spaced apart relationship fastened to one end of a rod. A pair of plates interconnecting the ends of the rolling devices and the rolling devices, form an opening through which a circular hoop, having a circular cross-section is captured. The hoop and the propelling device are joined together thereby eliminating the hazard of children chasing a hoop that has escaped from their immediate vicinity.
U.S. Pat. No. 3,001,325 issued on Sept. 26, 1961 to J. M. Riccobono et al discloses a convoluted termination at one end of a hoop rolling and guiding device adapted to control a circular hoop having a circular cross-section, in various states of rolling motion.
U.S. Pat. No. 3,464,149 issued on Sept. 2, 1969 to L. R. Batterson et al teaches a control device for a hoop having an elongated control rod having one end which is used to rotatably drive the hoop in a substantially upright longitudinally aligned attitude with respect to the control rod when a pushing force is exerted on the control rod so as to propel the hoop in a forward direction.
All of the aforementioned patents suffer the common deficiency of engaging a hoop with propelling or manipulative forces of similar character when applied to the outermost or innermost surfaces of a circular hoop, having a circular cross-section. Thus, the hoop activity is restricted to rolling or propelling the hoop in a captured or free state, utilizing a propelling implement.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a hoop and propelling device which enables the user to selectively capture the hoop for stopping purposes or in preparation to either propel or throw the hoop, utilizing a rod-like propelling device.
Another object of the present invention is to provide a hoop and propelling device which enables the user to frictionally engage a portion of the hoop's surface, without snapingly capturing the propelling device.
Still another object of the present invention is to provide a hoop and propelling device which may be tossed into the air, utilizing the propelling device and caught upon one free end of the propelling device by engaging the innermost and outermost edges of the hoop.
Yet another object of the present invention is to provide a hoop whose outermost marginal edges contact a supporting surface at two points thereby insuring greater stability while supporting the hoop.
Heretofore, hoop propelling devices in the main, contacted portions of the surface of the hoop so as to provide propelling and braking forces to the hoop. The instant invention provides the additional features of allowing the hoop to be propelled by contacting the outermost surface of the hoop, with moderate forces applied by the propelling device, in conventional fashion. When the forces applied are markedly increased, the hoop may be forced to stop rolling or may be captured by the propelling device preparatory to the hoop being tossed or propelled away from the propelling device with substantial tangential force applied to the outermost peripheral aspect of the hoop surface. Additionally, the interior curvature of the interior marginal edges of the hoop are designed to frictionally accommodate the distal end of the propelling device. Thus the hoop may be caught in mid-air by the propelling device, or, if desired, propelled away from the user, by engaging the distal end of the propelling device with the interior portion of the hoop at the far side thereof relative to the user. The utility and amusement value of the apparatus is thus vastly enhanced.
These objects, as well as other objects of the present invention, will become more readily apparent after reading the following description of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the instant invention shown being propelled by a user thereof.
FIG. 2 is a cross-sectional view taken along line 2--2 viewed in the direction of arrows 2--2 as shown in FIG. 1 illustrating a portion of the propelling device engaged within a cross-section of the hoop.
FIG. 3 is a side elevation view of the hoop.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The structure and method of fabrication of the preferred embodiment is applicable to a propelling device comprising an elongated rod terminated at one end and with a spherically shaped object fixedly secured thereto. The other end of the rod, constituting the propelling device, is destined to be grasped by a hand of the user. The hoop portion, having a generally circular annular shape, is preferably fabricated from a metallic material. A cross-section of the hoop contains an innermost U shaped section, whose mouth portion is projecting radially inwardly towards the origin of the hoop. The remaining portions of the cross-section comprises a similarly U shaped cross-section, whose mouth portion is directed radially outwardly from the center of the hoop, having the free marginal edges thereof, adjacent the mouth portion, turned inwardly towards each other and further inwardly towards the origin of the hoop. Thus, the spherically shaped terminal end of the propelling device may be captured by the inwardly turned marginal edges of the hoop, in a snap-in, snap-out fashion, when the force applied to the spherically shaped end is sufficient to force the sphere radially inwardly past the inwardly turned edges. The spherically shaped termination may frictionally engage the U shaped cross-section located at the inner aspect of the surface of the hoop.
The rod may be fabricated from a plastic material or from glass filaments so as to possess a degree of flexibility along the longitudinal axis thereof, thereby facilitating the user's ability to "cast" the hoop or to catch the hoop on a resilient rod-like element, further increasing the amusement value of the apparatus.
Now referring to the FIGS., and more particularly to the embodiment illustrated in FIG. 1 showing a user 10 whose hand 12 is shown grasping the proximal end 14 of road 16. The distal end 18 of the propelling device 20 is in touching engagement with hoop 22, shown resting upon supporting surface 24. The outermost edges 26 of the hoop contact surface 24 at two points. Rod 16 possesses flexible characteristics along the direction of dotted line 28.
FIG. 2 shows rod 16 equipped with a sphere 30 fixedly secured thereto at distal end 18. Hoop 22 has an innermost U shaped cross-section 32, including a mouth-like opening 34 and a pair of marginal edges 36, inwardly directed towards the origin of the hoop denoted by point 38. Sphere 30 is shown captured within void 40 formed by the outermost marginal edges 42, of the hoop, which are inwardly turned so as to form a pair of rolled-like sphere grasping edges 44. Moderate forces applied to rod 16, in the direction of arrow 46, will not overcome the position naturally assumed by rolled-like edges 44. When sufficient force is applied to rod 16, in the direction of arrow 46, rolled-like edges 44 are displaced outwardly allowing sphere 30 to successfully enter cavity 40. Points 26 appear at the outermost portions of rolled-like edges 44, as shown in FIG. 1.
The diameter of sphere 30 is sized to be somewhat smaller than the mouth opening 34, so as to permit sphere 30 to frictionally engage the innermost surface of U shaped cross-section 32 when desired. Ribs 48 join the opposing generally U shaped cross-sectional elements and lie in a plane parallel to the planes formed by edges 42.
FIG. 3 illustrates point 38 at the origin of hoop 22 and edges 36 being disposed intermediate point 38 and rolled-like edge 44. Rib 48 extends in annular fashion between edge 36 and rolled-like edge 44.
One of the advantages of the present invention is a hoop and propelling device which enables the user to selectively capture the hoop for stopping purposes or in preparation to either propel or throw the hoop, utilizing a rod-like propelling device. Another advantage of the present invention is a hoop and propelling device which enables the user to frictionally engage a portion of the hoop's surface, without snapingly capturing the propelling device.
Still another advantage of the present invention is a hoop which may be tossed into the air, utilizing the propelling device and caught upon one free end of the propelling device by engaging the innermost and outermost edges of the hoop.
Yet another advantage of the present invention is a hoop whose outermost marginal edges contact a supporting surface at two points thereby insuring greater stability while supporting the hoop.
Thus, there is disclosed in the above description and in the drawings, an embodiment of the invention which fully and effectively accomplishes the objects thereof. However, it will become apparent to those skilled in the art, how to make variations and modifications to the instant invention. Therefore, this invention is to be limited, not by the specific disclosure herein, but only by the appending claims.
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This disclosure pertains to a circular hoop having an outermost annular opening containing a pair of inwardly turned edges for snap-in engagement with a spherical shape that is fastened to one end of a hand held hoop propelling rod. An innermost notch, having a semi-circular cross-section having a mouth portion thereof directed towards the central axis of the hoop, is adapted to receive the spherical shape in frictional engagement therein.
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TECHNICAL FIELD
The present disclosure relates generally to a lubricant additive, and more particularly, to a lubricant additive to improve the anti-friction and anti-wear properties of a lubricant.
BACKGROUND
A lubricant is a substance introduced between two moving surfaces to reduce the friction and wear between them. Lubrication occurs when the opposing surfaces are separated by the lubricant (typically a fluid). In general, four regimes of lubrication are broadly defined based upon the mechanism by which the lubricant operates to reduce friction and wear between the moving parts. They are hydrodynamic regime (where a thick film of fluid separates the moving surfaces), mixed regime (where a thin film separates the moving surfaces), boundary regime (where most of the lubricant is squeezed out from between the moving parts), and enhanced pressure regime (where substantially all the liquid is squeezed out from between the moving parts and a thin solid film is formed on the surface of the moving parts). Lubricants are typically made by blending a base oil (most often petroleum fractions) with any number of additives. The additives impart special properties, such as reduced friction, reduced wear, increased viscosity, improved viscosity index, resistance to corrosion, oxidation, aging, and/or contamination, etc. to the lubricant. The functional group contained in the most commonly used anti-wear and anti-friction additives are boron (B), copper (Cu), phosphorous (P), sulfur (S), nitrogen (N), lead (Pb), and/or zinc (Zn).
Many of the lubricants and some additives currently being used are made of petroleum products that are toxic, making it increasingly difficult for safe and easy disposal. There has been an increasing demand for environmentally safe lubricants in recent years due to concerns regarding accidental spillage or leakage of the lubricants and increasingly strict government regulations restricting their use.
U.S. Patent Publication 2006/0009365 A1 issued to Erhan et al. (hereinafter the '365 publication) describes a sulfur modified vegetable oil that can be used as an additive for a lubricant. In the '365 publication, the lubricant additives are created by reacting epoxidized triglyceride oils (vegetable oil) with thiols (having the general formula HS—R′″). The resulting sulfur containing poly (hydroxy thioether) derivatives are environmentally safe because they are formed by modifying a vegetable oil.
Although the lubricant additive of the '365 publication may be environmentally safe, it may have some performance limitations. The sulfur containing additives of the '365 publication have the structural formula:
where R s , R s ′, R s ″ are characterized by the formula:
where R″ is hydrogen, a C1 to C22 hydrocarbon, 4-6 member heterocyclic ring, or a mixture thereof.
The additive of the '365 publication is restricted to sulfur as the functional group. Therefore, the additive does not offer flexibility in designing an additive with a different functional group which may be more suited to an application. For instance, the additive cannot be designed with phosphorous or an amine as the functional group to suit a particular application. In addition, the presence of the thio-ether group (C—SR′″) and the hydroxyl group (C—OH) in the additive of the '365 publication (see Formula 2) leads to a higher viscosity because of the inter and intra molecular hydrogen bonding within the thio-ether molecules.
The present disclosure is directed at overcoming one or more of the shortcomings of the prior art anti-friction and anti-wear lubricant additives.
SUMMARY OF THE INVENTION
In one aspect, the present disclosure is directed to a compound having the formula:
where X is a functional group chosen from:
and R is chosen from hydrogen, n-alkyl, iso-alkyl, aryl, heterocyclic ring, and nitrogen or sulfur containing group. The value of n in the compound ranges from 0 to 4.
In another aspect, the present disclosure is directed to a method of making a compound having the formula:
where X is a functional group chosen from:
and R is chosen from hydrogen, n-alkyl, iso-alkyl, aryl, heterocyclic ring, and nitrogen or sulfur containing group. The value of n in the compound ranges from 0 to 4. The method includes at least the step of changing an epoxidized seed oil to the compound.
DETAILED DESCRIPTION
The anti-friction and anti-wear additives of the current disclosure may be sulfur (S), phosphorous (P) and/or an amine (NH 2 ) group bearing structures. They are formed by reacting a commercially available epoxy seed oil starting material with a reagent containing sulfur (S), phosphorous (P) and/or an amine (NH 2 ) group molecules, under selected conditions. The resulting additive compound (the final product of the reaction) retains the natural functional properties, such as high flash point, amphiphilic character, surface active sites, high molecular weight, etc., of the vegetable oil. In addition, the additive compound may also contain S, P and/or NH 2 molecules to produce functional groups that generate a stable chemical boundary film to reduce friction and wear during metal-metal contact.
The starting material may be derived by epoxidizing commonly available seed oils having a triglyceride structure with at least one site of unsaturation. The seed oil may include, but not limited to, vegetable oils, plant oils and plant-like synthetic and semi-synthetic triglycerides. For example, the epoxy seed oil starting material may be derived by epoxidizing cotton seed oil, soybean oil, castor oil, canola oil, sunflower oil, corn oil, tung oil, palm oil peanut oil, grape oil, or other common seed oils. A generic C18 seed oil structure and an epoxy seed oil structure are represented by the following formula:
wherein n represents the number of unsaturated sites. The number of these unsaturated sites can range from 0 to 4. The epoxy seed oil may retain the basic molecular structure of seed oil but may have its unsaturated sites (carbon double bonds C═C) replaced with epoxy rings (oxirane ring —C—O—C—), that is, epoxidized. In some applications more than 90% of the unsaturated sites may be epoxidized. The degree of epoxidization may be such that there can be at least 2 (such as at least 3) oxirane rings per molecule of the seed oil. For example, epoxidized soybean oil having 3-7 oxirane rings per molecule may be used as the starter material. It is contemplated that in some applications, a seed oil may be epoxidized to be used as the starting material, while in other applications a commercially available epoxy seed oil may be used as the starting material. Any known process, such as that described by Qureshi et al. (Polymer Science and Technology, Vol. 17, Plenum Press, p. 250), which is incorporated by reference herein, may be used for epoxidizing the seed oil.
From the epoxidized seed oil, the compound can be formed. In at least one embodiment, the epoxidized seed oil may be reacted with an organophosphorous acid derivative. Organophosphorous acid derivatives include, but are not limited to, phosphorous, thiophosphorous, or aminothiophosphorous containing acid or their derivatives. For example, 2-carbamimidoylsulfanylethoxy-ethoxy-phosphinic acid anhydride (C 5 H 12 N 2 O 7 P 2 S), which is an organophosphorous acid anhydride, may serve as the reagent. These reagents may be represented by the structural formulas:
wherein R is chosen from a hydrogen (H), n-alkyl, iso-alkyl, aryl, heterocyclic ring, and N or S containing group.
The reaction of the epoxy seed oil starting material with the reagent may be a one-step or a two-step process. For both the one-step and the two-step processes, the ratio of the starting material to the reagent may be between approximately 1:3 and 1:8. In some applications, the ratio of the starting material to the reagent may be around 1:5.
In the one step process, the epoxy seed oil may be reacted with the reagent under controlled conditions at room or slightly elevated temperature. The reaction temperature may depend upon the reagent, and in some cases may be (or slightly exceed) the refluxing temperature of the reagent. This reaction temperature may range, for example, from about 50° C. to about 200° C., and may take place in an inert atmosphere in an organic solvent media, such as methylene chloride. In some cases, N 2 gas may be bubbled through the reaction mixture to create an inert atmosphere. The one-step reaction of the starting material with the reagent represented by Formula 4 is exemplified by the formula:
wherein 1 represents the epoxy seed oil, 2 represents the reagent, and 3 represents an embodiment of the resulting lubricant additive. The one-step reaction of the starting material with the reagent represented by Formula 5 is exemplified by the formula:
wherein 1 represents the epoxy seed oil, 4 represents the reagent, and 5 represents another embodiment of the resulting lubricant additive.
As represented in Formulas 6 and 7, each fatty acid chain of the lubricant additive 3 or 5 has an adjacent hydroxyl group and a phophate-ester (or thioaminophosphorous) group (the functional groups) attached to a carbon of the opened epoxy ring (CH—CH) structure. Those functional groups may be attached to either of the carbon atoms in the opened epoxy ring structure. In some cases, the functional groups may be attached on all the opened epoxy ring structures in the epoxy seed oil molecule, while in other cases, the functional groups may be attached to only some of the epoxy rings in the epoxy seed oil molecule. In other words, the epoxy seed oil may have one or more of its unsaturated sites replaced by the functional groups. In some applications, more than 90% of the unsaturated sites may be replaced by the functional groups.
The two-step process may include two distinct steps to create the final lubricant additive. In the first step, a di-hydroxylated (di-OH) product of the epoxy seed oil may be formed by reacting the epoxy seed oil under controlled conditions with water (H 2 O) in the presence of a mild acid catalyst (H + ), such as perchloric acid (HClO 4 ), at around 100° C. The chemical reaction of the first step in the two-step process may be exemplified by the following reaction:
wherein 1 represents the epoxy seed oil and 6 represents the di-hydroxylated product. That di-hydroxylated product may be separated and may serve as the starter material in the second step of the two-step process.
In the second step of the two-step process, the di-hydroxylated product, obtained from the reaction in the first step (Formula 8), may be reacted with an organophosphorous acid derivative (for instance, an organophosphorous acid anhydride), such as one of the reagents described by Formula 4 and Formula 5, to produce the lubricant additive. The reaction temperature may depend upon the selection of the reagent and in some cases may range from about 50° C. to about 200° C., and take place in an inert atmosphere in an organic solvent media. In some cases, N 2 gas may be bubbled through the reaction mixture to create an inert atmosphere.
Depending upon the reagent used (that represented by Formula 4 or Formula 5), the chemical reaction of the second step in the two-step process may be exemplified by the following reactions:
wherein 6 represents the di-hydroxylated product of the epoxy seed oil, 2 and 4 represents the reagents used, and 3 and 5 represent embodiments of the resulting lubricant additive. As in the reactions exemplified by Formulas 6 and 7, the reagent addition may take place on either carbon atom of the opened epoxy chain. Also, in some cases reagent additions may take place in substantially all the epoxy chains while in other cases, reagent addition may take place only at a few sites.
The final lubricant additive (3 and 5) obtained in each case (Formula's 6, and 7) may be dictated by the reagent used, and may consist of a mixture of the epoxy seed oil and the lubricant additive. The conversion efficiency of the epoxy seed oil to the lubricant additive may range from about 50% to about 90% depending upon the reagent and the process used (one-step or two-step) for the conversion. The final lubricant may have the functional group (derived from the reagent used) attached to the primary oil molecular structure. The final lubricant obtained following the one-step or the two-step process may be further purified, for example, using solvent washing.
INDUSTRIAL APPLICABILITY
The disclosed lubricant additive may be used with any lubricant used to reduce friction and wear between parts. For example, the additives of the current disclosure may be used with lubricant oils used in internal combustion engine or any other machine applications. The disclosed lubricant additives are made from seed oils that are environmentally safe and provide excellent hydrodynamic lubricity. The epoxy seed oils are chemically modified to attach selected functional groups in the epoxy seed oil molecule to improve the lubrication characteristics of the epoxy seed oil in the extreme pressure regime of lubrication. The chemical modification can preserve the inherent hydrodynamic lubrication characteristics of the epoxy seed oil, while imparting enhanced lubrication characteristics in the enhanced pressure lubrication regime. In order to better illustrate the disclosed lubricant additives, a one-step and a two-step process of making a lubricant additive covered in this disclosure is described.
Following the one-step process, commercially available 98% pure epoxidized soybean oil may be dissolved in an organic solvent methylene chloride and used as the starting material. Perchloric acid may be added drop-wise into the starting material. The organophosphorous acid anhydride reagent, C 5 H 12 N 2 O 7 P 2 S, may then be added to the mixture drop-wise to the mixture in the approximate ratio 5:1. The reaction mixture may be stirred continuously for good mixing. Nitrogen gas may be bubbled through the mixture to maintain an inert ambient. The mixture may be heated and maintained at about 60° C. for about 4 hours. After the reaction is complete, the mixture may be cooled to room temperature and the organic phase washed with sodium bicarbonate solution and DI water. The organic phase may then be further dried using anhydrous magnesium sulfate, filtered and solvent removed by distillation to obtain the lubricant additive.
Following the two-step process, commercially available 98% pure epoxidized soybean oil may be mixed with excess water and stirred vigorously. To this mixture, perchloric acid may be added drop-wise and the resulting mixture heated and maintained at about 100° C. for about 4 hours. The reaction mixture may be cooled and the organic phase extracted with the organic solvent methylene chloride. The dihydroxylated oil may then be recovered by removing the solvent by vacuum distillation. The recovered dihydroxylated oil may then be reacted with the organophosphorous acid anhydride reagent, C 5 H 12 N 2 O 7 P 2 S. The reaction may be maintained in an inert atmosphere using nitrogen gas. The reaction mixture may be heated to about 60° C. and maintained at this temperature for about 4 hours. The reaction mixture may be stirred while being maintained at the 60° C. temperature. After the reaction is complete, the mixture may be cooled to room temperature and the organic phase washed with sodium bicarbonate solution and DI water. The organic phase may be further dried using anhydrous magnesium sulfate, filtered, and solvent removed by distillation to obtain the lubricant additive.
The additives of the current disclosure can be designed with a functional group comprising sulfur, phosphorous and/or amine groups depending upon the reagent used. Therefore, the additives can be tailored to generate selected functional groups suited for a particular application.
The additives of the current disclosure can also have a low viscosity. The bulk of the functional groups attached to the epoxy seed oil molecule can reduce the free hydrogen bonding sites available, thereby leading to a low viscosity.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed lubricant additives and the method of making them. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of anti-friction and anti-wear additives for lubricants. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.
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The present disclosure is directed to compounds and methods of making the compounds (3, 5) having the formula:
where X is a functional group chosen from:
and wherein R is chosen from hydrogen, n-alkyl, iso-alkyl, aryl, heterocyclic ring, and nitrogen or a sulfur containing group, and n ranges from 0 to 4.
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CROSS-REFERENCE TO RELATED CASE
The dark box and the sheet withdrawing apparatus which are described and shown in the present application are identical with the dark box and the sheet withdrawing apparatus which are shown, described and claimed in the commonly owned copending patent application Ser. No. 07/926,922 filed Aug. 7, 1992 by Pietsch, Schausberger, and Vaessen for "Dark box for storage of exposed light sensitive sheets and apparatus for withdrawing sheets therefrom".
BACKGROUND OF THE INVENTION
The invention relates to the treatment of light sensitive materials in general, and more particularly to improvements in the treatment of exposed flexible light sensitive sheet-like materials which are ready to be introduced into a developing machine. Still more particularly, the invention relates to improvements in methods of manipulating sheets of flexible light sensitive material which form one or more stacks in a dark box, e.g., in a magazine, cassette or an analogous receptacle or container for temporary storage of exposed sheets of light sensitive material.
X-ray equipment is utilized in numerous fields, for example, in medicine as well as in various industries, particularly for nondestructive testing of substances, tissues, materials and/or products. Equipment which relies on X-rays employs sheets which carry coatings of radiation-sensitive material. When the exposure of a sheet to a required amount of radiation is completed, the resulting latent image must be developed in a suitable developing machine. As a rule, or in many instances, the exposed but undeveloped sheets are introduced into a dark box while the dark box is confined in a darkroom, and the dark box is closed and sealed upon introduction of a desired number of exposed sheets or when the dark box is filled to capacity. The thus closed and sealed dark box is ready to be transported to a developing machine. A dark box which is ready to be emptied is coupled to a so-called feeder which withdraws discrete sheets, one after the other, and introduces the withdrawn sheets into a developing machine.
Sheets which are coated with radiation sensitive material are likely to exhibit, at least at times, a more or less pronounced tendency to adhere to each other. This creates problems when a feeder is called upon to withdraw single sheets, i.e., to withdraw successive uppermost or topmost sheets of a pile or stack of superimposed sheets. The situation is often aggravated due to the fact that the sheets are stacked in a dark box. Attempts to overcome the just outlined problem, i.e., to more reliably segregate successive uppermost sheets of a stack from the sheets immediately below them, include the utilization of suction cups which are caused to slightly flex portions of the uppermost sheets so that the tendency of neighboring sheets to adhere to each other is reduced or eliminated and the uppermost sheet can be readily extracted from the dark box. In most instances, such flexing of portions of uppermost sheets of a stack of radiation-sensitive sheets suffices to ensure that the feeder can admit into a developing machine discrete radiation sensitive sheets which carry latent images and are ready to be treated in a conventional manner, e.g., by causing them to pass through a series of baths prior to entering a drying chamber. In order to further enhance the likelihood of separation of each uppermost sheet from the sheet or sheets immediately therebelow, certain presently known feeders are designed in such a way that the suction cup or suction cups maintain the attracted portion of the uppermost flexible sheet in flexed condition for a certain interval of time which should suffice to ensure separation of the next-to-the-uppermost sheet from the flexed portion of the uppermost sheet. The aforementioned interval is variable to take into consideration the differences between various sheets and/or various formats of sheets. Such versatility of the feeder further enhances the likelihood of reliable separation of successive uppermost sheets of a stack of sheets from the immediately following sheets.
In accordance with a further proposal, apparatus which are used to transfer flexible sheets of exposed radiation sensitive material from a magazine or cassette into a developing machine are provided with means for monitoring successive extracted uppermost sheets in order to ascertain whether or not each extracted sheet has been extracted alone. If the monitoring system detects simultaneous extraction of two or more coherent sheets, such coherent sheets are returned into the magazine or cassette and the extracting or withdrawing procedure is repeated.
OBJECTS OF THE INVENTION
An object of the invention is to provide a dark box which contains one or more stacks of superimposed (overlapping) exposed but undeveloped light sensitive sheets.
Another object of the invention is to provide a method which renders it possible to reliably extract discrete uppermost or topmost sheets from each stack of superimposed sheets in the dark box.
A further object of the invention is to provide a method which renders it possible to rapidly empty the contents of a dark box.
An additional object of the invention is to provide a method which facilitates separation of coherent sheets during extraction from a dark box.
Still another object of the invention is to provide a method which renders it possible to enhance the effectiveness of separation of successive uppermost sheets of a stack of overlapping sheets if the first attempt at extraction of a discrete uppermost sheet fails to result in extraction of a single sheet.
A further object of the invention is to provide a novel and improved method of intensifying the separation of an overlapping sheet from the overlapped sheet in a stack of sheets if the initial separation attempt or attempts remain unsuccessful.
Another object of the invention is to provide a novel and improved method of conveying exposed but undeveloped light sensitive sheets into one or more developing machines.
An additional object of the invention is to provide a novel and improved method of arraying exposed but undeveloped light sensitive sheets upon extraction of such sheets from a dark box.
Still another object of the invention is to provide a method which renders it possible to treat light sensitive sheets gently even if at least some of the sheets must be repeatedly introduced into and extracted from a dark box.
A further object of the invention is to provide a novel and improved method of rapidly evacuating the contents of a dark box which contains two or more stacks of superimposed identical or different exposed but undeveloped light sensitive sheets.
An additional object of the invention is to provide a novel and improved method of monitoring extracted sheets of light sensitive material.
Another object of the invention is to provide a method which is sufficiently reliable to ensure that a dark box must be opened in a darkroom by hand only in certain very infrequent instances, for example, when one attached to the neighboring sheets for another reason.
Still another object of the invention is to enhance the reliability of a method which involves repeated extraction of certain sheets from the dark box.
A further object of the invention is to provide a method which can be practiced in connection with sheets of many different formats with the same degree of reliability.
An additional object of the invention is to provide a method which can be practiced by resorting to relatively simple, compact and inexpensive apparatus.
Another object of the invention is to provide a method which can be practiced for introduction of sheets of any desired format into all or nearly all available developing machines.
A further object of the invention is to provide a method which can be automated to a desired extent and which can be practiced in existing processing laboratories for X-ray films, other types of films and/or photographic paper.
An additional object of the invention is to provide a method which renders it possible to expedite the introduction of sheets into a developing machine so that the machine can be used to capacity.
SUMMARY OF THE INVENTION
One feature of the present invention resides in the provision of a method of withdrawing flexible light sensitive sheets from a dark box wherein the sheets form at least one stack of superimposed sheets including an uppermost sheet and wherein at least one sheet beneath the uppermost sheet tends to adhere, at times, to the uppermost sheet. The method comprises the steps of attracting a selected portion of the uppermost sheet by suction to at least one pneumatic lifting device (e.g., a device employing one or more suction cups), at least slightly flexing the attracted selected portion of the uppermost sheet above and away from the remainder of the stack for a first interval of time to thus promote separation of the uppermost sheet from the sheet beneath the uppermost sheet, at least partially extracting the thus attracted and flexed uppermost sheet from the dark box, monitoring the extracted uppermost sheet for the presence of one or more sheets which adhere to the extracted uppermost sheet, returning the extracted uppermost sheet and the adhering one or more sheets beneath the uppermost sheet into the dark box upon detection of one or more adhering sheets, attracting a selected portion of the returned uppermost sheet by suction to the at least one pneumatic lifting device, thereupon flexing the attracted selected portion of the returned uppermost sheet above and away from the remainder of the at least one stack for a different (preferably longer) second interval of time, and thereupon at least partially extracting the twice flexed uppermost sheet from the dark box. For example, the duration of the second interval of time can be at least approximately twice the duration of the first interval.
The method can further comprise monitoring the twice extracted uppermost sheet for the presence of one or more sheets which adhere to the twice extracted uppermost sheet, returning the twice extracted uppermost sheet and the adhering one or more sheets into the dark box upon detection of one or more adhering sheets, attracting a portion of the twice returned uppermost sheet by suction to the at least one pneumatic lifting device, thereupon flexing the thrice attracted portion of the uppermost sheet above and away from the remainder of the at least one stack (e.g., for an interval of time whose duration matches that of the first or second interval or whose duration departs from (particularly exceeds) the duration of each preceding interval), and thereupon extracting the thrice flexed uppermost sheet from the dark box.
The method can further comprise the steps of monitoring the thrice extracted uppermost sheet for the presence of one or more sheets which adhere to the thrice extracted uppermost sheet, and generating a detectable (optical and/or acoustic and/or other) signal upon detection of one or more sheets adhering to the thrice extracted uppermost sheet. The signal generating step can be carried out earlier, e.g., upon completion of the second monitoring step; however, it is presently preferred to carry out at least three monitoring steps prior to the signal generating step.
The first flexing step can include flexing the attracted portion of the uppermost sheet to a first extent, and the second flexing step can comprise flexing the attracted portion of the uppermost sheet to a different second extent, preferably to a second extent greater than the first extent.
If the improved method is resorted to for withdrawal of flexible light sensitive sheets from a dark box wherein the sheets form at least two stacks of superimposed sheets and each stack includes an uppermost sheet and at least one sheet beneath the uppermost sheet to the respective uppermost sheet, the first attracting step of the method includes attracting at least a portion of the uppermost sheet of each stack by at least one discrete pneumatic lifting device, the first flexing step comprises simultaneously flexing the attracted portions of the uppermost sheets above and away from the remainders of the respective stacks for a first interval of time and/or to a first extent to thus promote separation of the uppermost sheets from the sheets beneath the respective uppermost sheets, and the first extracting step includes extracting the thus flexed uppermost sheets from the dark box, either entirely or in part. The monitoring step of such method comprises monitoring the extracted uppermost sheets for the presence of one or more sheets which adhere to the attracted uppermost sheets, the returning step includes returning the extracted uppermost sheets and the adhering one or more sheets into the dark box upon detection of one or more adhering sheets, the second attracting step includes attracting at least a portion of each returned uppermost sheet by the respective at least one discrete pneumatic lifting device, the second flexing step includes flexing the attracted portion of each returned uppermost sheet above and away from the remainder of the respective stack for a longer second interval of time and/or to a different second extent, and the second extracting step comprises extracting each twice flexed uppermost sheet from the dark box.
The method can further comprise the step of introducing the twice flexed uppermost sheet into a developing machine.
Another feature of the invention resides in the provision of a method of withdrawing flexible light sensitive sheets from a dark box (e.g., a magazine or cassette) wherein the sheets form at least one stack of superimposed sheets including an uppermost sheet and wherein at least one sheet beneath the uppermost sheet tends, at times, to adhere to the uppermost sheet. This method comprises the steps of attracting a portion of the uppermost sheet by suction to at least one pneumatic lifting device, flexing the attracted portion of the uppermost sheet above and away from the remainder of the stack to a first extent to thus promote separation of the uppermost sheet from the sheet beneath the uppermost sheet, at least partially extracting the thus attracted and flexed uppermost sheet from the dark box, monitoring the extracted uppermost sheet for the presence of one or more sheets which adhere to the extracted uppermost sheet, returning the extracted uppermost sheet upon detection of one or more adhering sheets, attracting a portion of the returned uppermost sheet by suction to the at least one pneumatic lifting device, thereupon flexing the attracted portion of the returned uppermost sheet above and away from the remainder of the stack to a different second extent, and thereupon at least partially extracting the twice flexed uppermost sheet from the dark box. The step of flexing the attracted portion of the returned uppermost sheet can include flexing the uppermost sheet to a second extent greater than the first extent.
If the sheets in the dark box form at least two stacks of superimposed sheets, the first attracting step includes attracting at least a portion of the uppermost sheet of each stack by at least one discrete pneumatic lifting device, the first flexing step comprises simultaneously flexing the attracted portions of the uppermost sheets above and away from the remainders of the respective stacks to a first extent to thus promote separation of the uppermost sheets from the sheets beneath the respective uppermost sheets, the first extracting step includes at least partially extracting the thus flexed uppermost sheets from the dark box, and the monitoring step includes monitoring the at least partially extracted uppermost sheets for the presence of one or more sheets which adhere to the extracted uppermost sheets. The returning step then includes returning the extracted uppermost sheets and the adhering one or more sheets into the dark box upon detection of one or more adhering sheets, the second attracting step includes attracting a portion of each returned uppermost sheet by the respective at least one discrete pneumatic lifting device, the second flexing step includes flexing the attracted portion of each returned uppermost sheet above and away from the remainder of the respective stack to a different second extent, and the second extracting step includes at least partially extracting each twice flexed uppermost sheet from the dark box. The second flexing step can include flexing the attracted portion of each returned uppermost sheet to a second extent greater than the first extent.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved method itself, however, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic plan view of a dark box for temporary storage of one or more stacks of flexible light sensitive sheets, one section of the housing of the dark box being shown in the open position;
FIG. 2 is an enlarged fragmentary transverse sectional view of the dark box, with another section of the housing shown in the closed position;
FIG. 3a is a schematic partly elevational and partly sectional view of an apparatus which is utilized to transfer sheets of different formats from a dark box into one or more developing machines;
FIG. 3b shows the structure of FIG. 3a but with the suction cups in different angular positions;
FIG. 3c is an enlarged perspective view of a detail in FIG. 3a;
FIG. 4 is a similar partly elevational and partly sectional view of a modified apparatus which is provided with means for arraying simultaneously withdrawn sheets prior to introduction into a developing machine;
FIG. 5 is a front elevational view of certain component parts of means for monitoring the numbers of withdrawn sheets in the apparatus of FIGS. 3a-3c or FIG. 4; and
FIG. 6 is a sectional view substantially as seen in the direction of arrows from the line VI--VI in FIG. 5.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIGS. 1 and 2, there is shown a dark box M in the form of a relatively flat and substantially square or rectangular cassette or magazine for storage of piles or stacks 61 of sheets 60, 60a . . . (FIGS. 3a and 3b) of exposed but yet to be developed light sensitive material. The dark box M comprises a housing including a first or bottom section 1, a second or top section 2, and means (e.g., a hinge 62) for pivotally coupling the second section 2 to the first section 1 so that the section 2 is movable between an open position shown in FIG. 1 and a closed position which is shown in FIG. 2.
The inner side of the first section 1 is formed with a plurality of recesses in the form of elongated at least substantially parallel grooves 3, and the inner side of the second section 2 is also formed with a plurality of elongated at least substantially parallel recesses in the form of grooves 5. FIG. 1 merely shows three parallel grooves 3 and three parallel grooves 5 each of which is aligned with one of the grooves 3. The grooves 3 and 5 can removably receive the respective marginal portions of elongated partitions 4 (one shown in FIG. 2) which serve to divide the internal chamber 63 of the housing of the dark box M into a number of variable-capacity compartments 64 (two shown in FIG. 2). The partitions 4 can be transferred from first selected pairs into second selected pairs of aligned grooves 3, 5 in order to change the capacities of the neighboring compartments 64 in dependency on the formats of sheets 60, 60a . . . which are to be temporarily confined therein.
The partitions 4 constitute one set of parts for dividing the internal chamber 63 into compartments 64 of selected capacities. Such dividing means further comprises one or more walls 7 (only one shown in FIGS. 1 and 2) which are movable longitudinally of the adjacent grooves in order to select the effective length of the respective compartments 64. FIG. 1 and 2 show that the wall or walls 7 are installed in the first section 1 of the housing; each such wall is movable longitudinally of an elongated guide rail 6 between a pair of neighboring grooves 3, and each wall 7 can be separably secured to the first section 1 by at least one screw 8 or another suitable fastener. If the inner sides of the housing sections 1 and 2 are provided with only three grooves (3, 5) each, the internal chamber 63 can be subdivided into four compartments 64 which may but need not have identical widths (depending on the distribution of grooves 3 and of the aligned grooves 5) and the length of each of which is preferably variable by a discrete mobile wall 7. The depth of each compartment 64 is or can be such that each of these compartments can receive a pile or stack 61 of two, three or more superimposed sheets 60, 60a . . . having a particular format.
If the dark box M of FIGS. 1 and 2 is to store larger sheets, one or more or all partitions 4 are removed and/or shifted into different grooves 3 and/or 5, and the walls 7 are moved out of the way or shifted along the respective guide rails 6 to different positions to permit the establishment of one or more compartments 64 having a desired size (length and width) for one or more selected formats of flexible light sensitive sheets 60. For example, all of the partitions 4 can be removed to provide a single compartment 64 whose size matches or is less than that of the internal chamber 63, depending upon whether the wall or walls 7 are used to limit the length of the single compartment as seen in the longitudinal direction of the grooves 3 and 5. It is equally possible to distribute the parts 4 and 7 of the adjustable dividing means in such a way that the housing including the sections 1, 2 defines two, three or five or more compartments 64, depending on the formats of sheets 60 to be temporarily confined therein.
FIG. 2 shows that the head of the illustrated fastener 8 is spaced apart from the adjacent portion of the inner side of the second or top housing section 2 when the latter is caused to assume the closed or sealing position. In order to prevent the topmost sheet or sheets 60 in the adjacent compartments 64 from migrating along the inner side of the section 2 over the head of the illustrated fastener 8, the section 2 preferably supports a set of substantially U-shaped hold down devices 10 which can bear against the topmost sheets 60 in the adjacent compartments 64 to thus prevent any undesirable shifting of confined sheets when the section 2 has been pivoted to the closed or sealing position of FIG. 2. The provision of hold down devices 10 is particularly desirable when the sheets 60 in the neighboring compartments 64 are relatively small and/or when the closed dark box M is treated by inexperienced persons. The hold down devices 10 can be biased toward the inner side of the housing section 1 by suitable springs (not shown) to even further reduce the likelihood of uncontrolled shifting of confined sheets over the heads of the fasteners 8.
The second housing section 2 is provided with an opening 65 (indicated in FIG. 1 by broken lines) which can be closed and sealed by a substantially panel-like member or door 9 which is slidable in suitable ways (not specifically shown) of the section 2 between a first position in which the opening 65 is exposed and a second position in which the opening 65 is closed and sealed against penetration of radiation which could affect the quality of latent images on the sheets in their compartments 64. The aforementioned hold down devices 10 are or can be provided on the sealing-exposing member 9.
The opening 65 establishes one of two available paths for introduction of sheets into or for withdrawal of sheets from their respective compartments 64. The other path is established by the opening which develops when the second housing section 2 is pivoted from the closed position of FIG. 2 to the open position of FIG. 1.
The first housing section 1 is further provided with several (FIG. 1 shows four) circular depressions or sockets 11 which extend from the inner side toward but short of the outer side of the section 1 and each of which communicates with a slit-shaped passage 12 extending all the way to the outer side of the section 1. The purpose of the depressions 11 and of the associated slit-shaped passages 12 is to permit suction cups 25 (FIGS. 3a, 3b, 3c) or analogous sheet lifting devices of the sheet attracting, extracting, transferring and returning apparatus to draw atmospheric air when the adjacent portions of the respective compartments 64 do not contain any sheets. Thus, the depressions 11 and the passages 12 can be said to constitute component parts of means for monitoring the dark box M for the presence of sheets in the compartments 64. The suction cups 25 can extend all the way into the respective depressions 11 so that they draw air only from the atmosphere (through the respective passages 12 which, as already mentioned above, extend all the way to the outer side of the housing section 1). The pressure in the suction cups 25 is ascertained by a pressure sensing unit which is installed in or is associated with an evaluating or control unit 35 (FIGS. 3a and 3b) of the monitoring means forming part of the sheet attracting, flexing, extracting, transferring and returning apparatus.
The sections 1 and 2 of the housing of the dark box M are further provided with discrete U-shaped handles 13 and 14, respectively. Each of these handles carries two independently operable locking or closing elements 15, 16. The locking elements 15, 16 of the handle 13 can cooperate with similarly referenced locking elements of the handle 14 to maintain the second housing section 2 in the closed position of FIG. 2. This reduces the likelihood of accidental opening of the dark box M, e.g., during introduction into a darkroom or enclosure 49 which is shown in FIGS. 3a and 3b and forms part of the aforementioned sheet manipulating apparatus. The housing sections 1 and 2 can be made of any suitable material which prevents penetration of radiation into the chamber 63 when the section 2 is maintained in the closed position of FIG. 2 and the slidable exposing-sealing member 9 is maintained in the operative position of FIG. 1.
FIG. 2 shows that the housing sections 1 and 2 comprise sealing portions 1a, 2a which cooperate to prevent the penetration of radiation into the chamber 63 when the section 2 is maintained in the closed position.
An important advantage of the improved dark box M is that it can be rapidly converted for storage of a single stack 61, for storage of two stacks having sheets of identical size and shape or differently dimensioned and/or configurated sheets, or for storage of three or more stacks of identical or different sheets. Thus, if all of the partitions 4 are removed and the walls 7 are pushed out of the way or removed, the internal chamber 63 of the dark box M is ready to receive a single stack 61 of relatively large sheets 60. If a single partition is placed midway between the sidewalls of the housing sections 1, 2, the internal chamber 63 is divided into two equal compartments 64 each of which can receive a stack 61 of sheets 60. Other simple manipulations of the partition or partitions 4 and/or walls 7 will be carried out in order to provide three or more compartments 64 of desired size and shape.
The provision of grooves 3 in the inner side of the housing section 1 or the provision of grooves 5 in the inner side of the housing section 2 is optional, i.e., each partition 4 which is put to use to subdivide the chamber 63 can extend into a single groove 5 or into a single groove 3. The provision of grooves 3, 5 in each of the two housing sections 1, 2 is preferred at this time because, if a partition extends into a pair of aligned grooves 3 and 5, it is more likely to establish a combined light barrier and sheet-confining barrier all the way between two neighboring compartments 64.
The dimensions of the housing section 2 may but need not match the dimensions of the housing section 1. Furthermore, the hinge 62 can be replaced with other suitable means for movably coupling the sections 1 and 2 to each other. A hinge 62 is preferred at this time because it enables the person in charge to move the section 1 or 2 to the fully open position of FIG. 1 and to thus facilitate introduction of stacks 61 of sheets 60 into the compartment or compartments of the dark box M. The opening which develops in response to opening of the dark box M in a manner as shown in FIG. 1 can also serve for evacuation of sheets 60 from their compartment or compartments 64; however, it is normally preferred to provide the aforediscussed panel-like slidable member 9 which can seal the opening 65, i.e., to provide a separate opening for withdrawal of sheets 60. This ensures that the dark box M need not be fully opened upon introduction into the opening 20 of the enclosure 49 in the manipulating apparatus of FIGS. 3a and 3b. Moreover, it is simpler to automatically shift the member 9 to the open position, particularly in response to introduction of a certain portion of the closed dark box M into the inlet opening 20 of the enclosure 49.
The darkroom or enclosure 49 of the sheet manipulating apparatus which is shown in FIGS. 3a and 3b has the afore-mentioned inlet opening 20 for introduction of an at least partially filled dark box M. This apparatus further comprises means (such as a rubber-coated friction wheel or roller 71 of FIGS. 3a and 3b) for automatically moving the slidable closing-exposing member or door 9 to the open position in response to insertion of a certain portion of the dark box M into the internal space of the enclosure 49. Reference may be had to U.S. Pat. No. 4,049,142 granted Sep. 20, 1977 to Azzaroni. The roller 71 automatically shifts the cover 9 to open position in response to introduction of the dark box M into the opening 20. The means for simultaneously withdrawing two or more sheets 60 from the respective compartments 64 of the dark box M whose housing has been partially introduced into the enclosure 49 through the inlet opening 20 includes a linkage for the battery of (e.g., four) pneumatic lifting devices in the form of suction cups 25. Such linkage includes two elongated members 22 (e.g., pneumatic cylinder and piston units--see particularly FIG. 3c which are pivotable about the horizontal axes 21 and each of which is preferably of variable length. Each of the illustrated members or units 22 comprises a plurality of portions which are telescoped into each other so that they can select the distance of the suction cups 25 from the shafts 21. Each member or unit 22 carries at its free end (namely the end which is distant from the respective shaft 21) a lever 23 which is pivotable in and counter to the direction indicated by arrow A. One end of each lever 23 is articulately connected to the respective member or unit 22, and the other ends of these levers carry a rod-like support 24 for the battery of suction cups 25. As concerns the movements of suction cups 25 relative to the adjacent sheets 60, reference may be had again to U.S. Pat. No. 4,049,142 to Azzaroni as well as to commonly owned U.S. Pat. No. 4,591,140 granted May 27, 1986 to Illig et al. The means for raising and lowering the suction cups 25 includes pneumatic cylinder and piston units 74. The means for preventing the suction cups 25 from changing their orientation during movement between the solid-line and phantom-line positions of FIGS. 3a and 3b comprises a parallel motion mechanism including the rod-shaped members or units 22, cylinder and piston units 72, rigidly mounted connecting members 75 and the arms 76 of the levers 23. Thus, the undersides of the suction cups 25 are normally parallel to the sheets 60 in the respective compartments 64. The cylinder and piston units 72 serve to change the orientation of the suction cups 25 (compare the solid-line positions of the suction cup 25 which is shown in FIGS. 3a and 3b)in order to enhance separation of the respective topmost sheet 60 from the sheet 60a therebelow.
The means for monitoring the withdrawal of sheets 60 from the respective compartments 64 and the advancement of withdrawn sheets toward the inlet 32 of the illustrated single developing machine 33 (i.e., toward the outlet of the enclosure 49) comprises a trip 27 which is provided on at least one of the members 22 and can actuate a microswitch 26 serving to transmit signals to the control unit 35 of the monitoring means. Furthermore, at least one suction cup 25 carries an extension or trip 28 which also forms part of the monitoring means and can actuate a microswitch 29 serving to transmit signals to the control unit 35.
The means for conveying freshly withdrawn sheets 60 from the suction cups 25 toward and into the inlet 32 of the developing machine 33 comprises several pairs of advancing rolls (FIGS. 3a and 3b show two pairs 30, 31) which define an elongated path extending from the suction cups 25 (when these suction cups assume the phantom-line positions of FIGS. 3a and 3b) to the inlet 32.
The monitoring means of the apparatus which is shown in FIGS. 3a and 3b further comprises means 34 for ascertaining or counting the number of overlapping or partly overlapping sheets 60 which are being advanced along the aforementioned path toward and into the inlet 32 of the developing machine 33. The details of presently preferred ascertaining or counting means 34 are shown in FIGS. 5 and 6. One such ascertaining or counting means 34 is or can be provided for each suction cup 25.
Referring now to FIGS. 5 and 6, the ascertaining or counting means 34 which is shown therein comprises two pairs of rollers 40, 41 or analogous rotary members which define a nip 67 for sheets 60A, 60, 60a . . . , namely for those sheets which advance along the path defined by the pairs of advancing rolls 30 and 31. The rollers 40, 41 are disposed at opposite sides of the path for the sheets, and the rollers 40 of the lower pair are idler rollers which are rotatable about a fixed common horizontal axis. The upper rollers 41 are rotatable about a horizontal shaft 42 which is journalled in a mobile frame 68, and the latter is biased against a stop 69 by one or more coil springs 46 so that the rollers 41 tend to reduce the width of the nip 67 to a minimum value, e.g., zero.
The spring 46 which is shown in FIG. 6 further serves to bias a lever 45 in a clockwise direction so that the shorter arm of this lever bears against a pin 43 which is reciprocably mounted in the frame 68 and shares the movements of the rollers 41 toward and away from the rollers 40. The longer arm 47 of the lever 45 (which is fulcrumed at 44) cooperates with a photoelectronic scanning device 48 (e.g., a standard light barrier of the type known as TLP 1019 distributed by Toshiba) which transmits to the control unit 35 signals denoting the level of the rollers 41, i.e., the number of overlapping or partly overlapping sheets 60, 60a . . . in the nip 67. FIG. 6 shows the rollers 41 in their optimal positions, i.e., the number of sheets 60 in the nip 67 is one.
The operation of the apparatus which is shown in FIGS. 3a, 3b and 3c and embodies the structure of FIGS. 5 and 6 is as follows:
When the dark box M is properly inserted into the inlet opening 20 of the enclosure 49, the member 9 is automatically shifted to the open position by the roller 71 so that it exposes the opening 65 which affords access to the compartments 64 of the internal chamber 63. Movement of the exposing-sealing member 9 to open position can also be initiated by a signal from the control unit 35 which, in turn, receives a signal from a suitable sensor (not specifically shown) serving to detect a properly inserted dark box M in the inlet opening 20. A signal from the control unit 35 thereupon causes the units 74 to initiate a pivotal movement of members 22 about the axes of the respective shafts 21 and, if necessary, a pivotal movement of levers 23 at 37 so that the suction cups 25 leave the phantom-line positions of FIGS. 3a and 3b and descend into the dark box M to (solid-line) positions of registry with the respective depressions 11 in the inner side of the housing section 1. The aforementioned parallel motion mechanism 22, 72, 75, 76 ensures that the orientation of suction cups 25 remains unchanged during descent into the dark box M. The next step involves pivoting of the suction cups 25 from the solid-line positions of FIG. 3a to the solid-line positions of FIG. 3b in order to reliably separate the topmost sheets 60 from the neighboring sheets 60a. This involves actuation of the units 72 which cause the suction cups 25 to pivot at 37. The units 74 are thereupon actuated again until the trips 27 reach and actuate one or more switches 70. This takes place when the thus lifted sheets 60 can be taken over by the rollers 30. The character 73 denotes in FIGS. 3a and 3b a pneumatic regulator which initiates and controls the operation of the units 22, 72, 74 (i.e., the movements of the suction cups 25) in response to signals from the control unit 35. Each suction cup 25 carries a microswitch (reference may be had to commonly owned U.S. Pat. No. 4,759,679 granted Jul. 26, 1988 to Muller) which is actuated by the uppermost sheet 60 in the respective compartment 64. Downward movement of the suction cups 25 is terminated when at least one of the just mentioned microswitches is actuated by the adjacent sheet 60. The control unit 35 then connects the suction cups 25 with a pump or with another suitable suction generating device (not shown) so that the suction cups begin to attract the adjacent uppermost sheets 60 (or at least one of these suction cups attracts the uppermost sheet 60 of the respective stack 61).
As already described above, the control unit 35 thereupon transmits a signal which causes the levers 23 to pivot about the axis of the member 37 in the direction of arrow A so that the attracted uppermost sheet or sheets 60 are at least partially extracted from the dark box M through the opening 65, and the control unit 35 thereupon transmits one or more additional signals which cause the linkage including the members 22 to manipulate the levers 23 in such a way that the leader(s) of the at least partially extracted sheet(s) 60 enters or enter the nip of the first pair of rolls 30 of the means for conveying sheets (one shown at 60A) from the suction cups 25 into the inlet 32 of the developing machine 33, i.e., toward the outlet of the enclosure 49. The developing machine 33 can be of the type known as STRUCTURIX NDTM which is distributed by the assignee of the present application.
The just described withdrawal of one or more uppermost sheets 60 involves slight flexing of the leaders of such uppermost sheets by the units 72, and this almost invariably results in separation of the flexed uppermost sheet or sheets from the sheet or sheets 60a immediately below. Introduction of the leaders of withdrawn uppermost sheets 60 into the nip of the rolls 30 can also involve a change of the length of members or units 22. FIGS. 3a and 3b show a suction cup 25 once in a phantom-line position and once by solid lines. When in the solid-line positions, the suction cups 25 are adjacent the stacks 61 of sheets 60, 60a . . . in the respective compartments 64 of the internal chamber 63 which is defined by the sections 1, 2 of the housing forming part of the dark box M. When in the phantom-line positions, the suction cups 25 are in the process of introducing the leaders of simultaneously withdrawn uppermost sheets 60 into the nip of the advancing rolls 30. FIGS. 3a and 3b further show that the effective length of the members 22 in phantom-line positions exceeds the effective length of these members in the solid-line positions.
The control unit 35 has several inputs which transmit to its signal evaluating and processing circuit a number of different signals. Thus, the control unit 35 receives signals when the suction cups 25 assume the solid-line positions of FIG. 3 and when the suction cups are thereupon connected with a suitable suction generating device. A subatmospheric pressure will develop in a suction cup 25 only if the respective compartment 64 contains at least one sheet 60 and if the suction cup is sufficiently close to such at least one sheet to prevent the inflow of air from the surrounding atmosphere above the at least one sheet. Since the height of each stack or pile 61 of sheets 60 can vary and often varies from compartment to compartment, it can happen that a first lowering of suction cups 25 from the phantom-line positions to the solid-line positions of FIGS. 3a and 3b results in the establishment of vacuum in a single suction cup or in fewer than all four suction cups. This means that the first lifting of suction cups 25 from the solid-line positions to the phantom-line positions of FIG. 3 will result in withdrawal of one, two or three sheets 60 (rather than four sheets, it being assumed here that the internal chamber 63 of the housing of the dark box M which is shown in FIGS. 3a and 3b is divided into four compartments 64 and that each such compartment contains a stack 61 of exposed but undeveloped sheets 60). The same procedure is repeated again and again, as often as necessary, until the height of all four stacks 61 is at least nearly the same. From then on, each of the four suction cups 25 lifts the uppermost sheet 60 off the respective stack 61 (i.e., from the respective compartment 64) during each movement from the solid-line position to the phantom-line position of FIG. 3.
The aforementioned microswitches which are associated with the suction cups 25 transmit to the control unit 35 signals which denote whether or not the respective suction cups have developed a vacuum upon movement to the solid-line position of FIGS. 3a and 3b. Thus, the control unit 35 can ascertain which of the suction cups 25 is about to lift a sheet 60, and the control unit 35 can transmit an advance signal to the respective ascertaining or counting device 34 of the monitoring means. For example, if the height of all four stacks 61 is the same from the very start of operation of the sheet manipulating apparatus of FIGS. 3a, 3b, 3c or after a certain number of cycles which are performed by the suction cups 25, each of the four ascertaining or counting devices 34 receives an advance signal that a sheet 60 is about to reach the nip 67 of its rotary members 40, 41. This causes the longer arms 47 of the respective levers 45 to move into the paths of radiation which is emitted by the radiation sources of the respective photoelectronic scanning devices 48. The control unit 35 receives an "error" or "defect" or "malfunction" signal if a suction cup 25 is under vacuum but the corresponding ascertaining device 34 fails to receive a sheet 60 after elapse of a certain interval of time thereafter. The detection of such "defect" signal induces the control unit 35 to start the motor or motors for the rolls 30 in reverse so that the respective sheet 60 is advanced backwards (arrow B in FIG. 3a) and is returned into the respective compartment 64. The next step involves renewed advancement of the retracted sheet 60 in the direction toward the inlet 32 of the developing machine 33.
If the arm 47 of a particular lever 45 interrupts the radiation beam for the associated photoelectronic device 48 for a short interval of time, this indicates to the control unit 35 that the respective nip 67 contains at least two superimposed or overlapping sheets 60, 60a . . . because the pin 43 of the respective ascertaining means 34 has been advanced beyond that position or beyond that level which is indicative of the presence of a single sheet 60 in the respective nip 67. In other words, the respective suction cup 25 has withdrawn two or more sheets 60, 60a . . . from the respective stack 61 in a single stage of its operation (movement from the solid-line position to the phantom-line position of FIG. 3a or 3b). This, too, induces the control unit 35 to reverse the direction of rotation of the rolls 30 in order to return the sheets 60 into the respective compartments 64, and to thereupon again drive the rolls 30 in a direction to advance sheets 60 toward the inlet 32 of the developing machine 33. Furthermore, and particularly if the control unit 35 receives a certain number of "defect" signals which denote that one or more suction cups 25 have lifted two or more sheets 60, 60a . . . in a single withdrawing step, the control unit 35 can slow down the withdrawing operation or it can slow down one or more selected stages of the withdrawing operation in order to provide more time for separation of (flexed) topmost sheets 60 from the sheets 60a immediately below them. The arrangement is such that the control unit 35 prolongs the intervals of time following pivoting of the levers 23 in directions which are indicated by the arrow A in FIGS. 3a and 3b before the members 22 are pivoted at 21 to lift the suction cups 25 to their phantom-line positions.
Alternatively or in addition, and assuming that one or more suction cups 25 exhibit a tendency to simultaneously lift two or more overlapping sheets 60, 60a . . . , the control unit 35 can cause the units 72 to change the extent of pivotal movement of the levers 23 in the direction of arrow A, i.e., to alter (preferably increase) the extent of flexing of the topmost sheets 60 which is also conducive to more reliable separation of topmost sheets from the sheets immediately below them. In accordance with a presently preferred embodiment, the control unit 35 doubles the length of intervals of time which elapse following pivoting of the levers 23 in the direction of arrow A and preceding pivoting of the members 22 in a counterclockwise direction (as viewed in FIGS. 3a and 3b). Thus, if the control unit 35 receives a signal that at least one of the suction cups 25 has lifted two or more sheets 60, 60a . . . , this control unit simply increases by 100 percent or approximately 100 percent the interval of time which elapses between pivoting of the levers 23 in the direction of arrow A and pivoting of the members 22 in a counterclockwise direction. This has been found to enormously increase the likelihood of extraction of discrete uppermost sheets 60 (without the neighboring sheets 60a). Withdrawal of a particular sheet 60 (which has been withdrawn jointly with one or more sheets 60a . . . below it) can be repeated a certain number of times (e.g., three times) so that the fourth attempt involves the retention of the leaders of uppermost sheets 60 in upwardly flexed condition for an interval of time which is four times the original interval. This has been found to practically invariably ensure withdrawal of a single sheet 60 at a time by each of the suction cups 25. If the above outlined undertakings still fail to result in proper separation of uppermost sheets 60 from the sheets 60a immediately below them, the control unit 35 is preferably designed to generate an acoustic, optical and/or other readily detectable signal which informs an attendant that she or he must gain access to the internal space of the enclosure 49 in order to pivot the housing section 2 to the open position and to manually separate the uppermost sheet 60 from the immediately following sheet 60a of each stack 61 or of that stack wherein the leaders of sheets tend to adhere to each other. This can take place when one or more sheets are damaged (e.g., torn) and are interlaced with the neighboring sheets.
When a suction cup 25 detects an empty compartment 64 or when the withdrawal of the last or lowermost sheet of a stack 61 in a particular compartment 64 is completed, such suction cup is free to descend into the respective depression or socket 11 and to draw atmospheric air through the respective passage 12. Thus, the pressure in such suction cup 25 does not drop when the suction cup is connected to the aforementioned suction generating means. When the same situation develops in connection with each and every suction cup 25, the control unit 35 generates a signal which causes closing of the exposing-sealing member 9 and ejection of the dark box M from the enclosure 49 via inlet opening 20. Alternatively, the control unit 35 can generate a signal which informs an attendant that the emptied dark box M can be withdrawn by hand.
However, and since the establishment of subatmospheric pressure in a given suction cup 25 can also take place for reasons other than exhaustion of the supply of sheets 60 in a particular compartment 64, the trips 27 of the members 22 are preferably dimensioned and positioned to actuate the respective switches 26 when all of the suction cups 25 have descended into the respective depressions 11 so that the control unit 35 again receives a signal which indicates that the dark box M which extends into the inlet opening 20 of the enclosure 49 is empty and is thus ready to be replaced with a dark box which contains one or more stacks 61 of sheets 60.
The purpose of the microswitch or microswitches 29 is to transmit signals which indicate to the control unit 35 that the suction cups 25 should be disconnected from the suction generating means (such as the aforementioned pump). The extension or extensions 28 of one or more suction cups 25 will engage the adjacent microswitch or microswitches 29 when the leaders of the withdrawn sheets 60 are located in the nip of the rolls 30 so that they can be reliably conveyed or advanced toward the inlet 32 of the developing machine 33.
The microswitch(es) 26 and/or 29 can be replaced with optoelectronic sensor means or with other suitable signal generating and transmitting means without departing from the spirit of the invention.
The internal space of the enclosure 49 preferably accommodates one or more blowers 36 or other suitable means for raising the pressure in the internal space slightly above atmospheric pressure or above the pressure in the developing machine 33. This ensures that vapors of developing solution cannot penetrate from the machine 33 into the enclosure 49 and thus cannot affect the quality of latent images on the sheets 60 which are still confined in the dark box M or are in the process of being withdrawn from the dark box to be transported toward and into the inlet 32. Furthermore, vapors which develop in the machine 33 could bring about rapid corrosion of metallic parts in the internal space of the enclosure 49.
An advantage of the apparatus which is shown in FIGS. 3a, 3b and 3c is that it can simultaneously withdraw two or more sheets from a dark box M in the inlet opening 20. This renders it possible to empty the contents of a dark box within a fraction of the time which is required by conventional feeders. The developing machine 33 can be of standard design which is capable of processing larger and smaller exposed sheets and which is equally capable of simultaneously developing two or more sheets having identical or different formats.
The monitoring means of the apparatus of FIGS. 3a, 3b and 3c can be replaced with simpler or more complex monitoring means without departing from the spirit of the invention. As a rule, it suffices to provide monitoring means whose constituents can perform the aforediscussed functions of ascertaining the presence or absence of stacks 61 and sheets 60 in the respective compartments 64 (by ascertaining the pressure in the suction cups 25), of ascertaining the number of sheets which are withdrawn by a suction cup 25 during movement from the solid-line position to the phantom-line position of FIG. 3a or 3b, and by repeating the introduction of a sheet which is the uppermost one of two or more superimposed sheets in the nip of the rolls 30.
The levers 45 of the ascertaining or counting devices 34 can be replaced with other means for actuating the respective optoelectronic devices 48. The arrangement which is shown in FIGS. 5 and 6 is preferred at this time because it is capable of ensuring that the extent of movement of the longer arm 47 relative to the optoelectronic device 48 greatly exceeds the extent of upward movement of the rotary members 41 when the nip 67 receives two or more overlapping sheets 60, 60a . . . This enhances the reliability of the ascertaining means 34. Such ascertaining means can detect the absence of a sheet 60 in the nip 67, the presence of a singel sheet 60 in the nip, or the presence of two or more sheets 60, 60a . . . in the nip.
The developing machine 33 of FIGS. 3a and 3b is assumed to be capable of simultaneously processing four discrete sheets 60, i.e., the inlet 32 is long enough (as seen at right angles to the plane of FIG. 3a or 3b) to permit simultaneous passage of a number of sheets 60 (namely one sheet for each suction cup 25 except, of course, if the apparatus of FIGS. 3a and 3b is designed to employ more than one suction cup per sheet). FIG. 4 shows a modified transferring apparatus which is provided with a converting unit 50 downstream of the conveying or advancing means including the pairs of rolls 30 and 31. The unit 50 is designed to deliver simultaneously withdrawn sheets 60 into the inlet 32 of a modified developing machine 38, e.g., a machine known as STRUCTURIX NDTE which is distributed by the assignee of the present application. The machine 38 is operated in a dark chamber and includes a platform 39 immediately beneath the inlet 32. Heretofore, sheets 60 were manually fed into the inlet 32 of the machine 38 by sliding them along the platform 39. The adapter 50 automatically transfers sheets 60 from the path defined by the rollers 30, 31 onto the platform 39. The converting unit or adapter 50 comprises an arcuate deflector 51 which is located downstream of the rolls 31 and deflects sheets 60 coming from the nip of the rolls 31 onto an endless belt or chain conveyor 52 which advances the sheets onto the platform 39.
All other parts of the apparatus which is shown in FIG. 4 are or can be identical with or similar to corresponding parts of the apparatus of FIGS. 3a, 3b and 3c.
The adapter 50 enables a machine (38) of earlier vintage to receive sheets 60 from an apparatus of the type described with reference to FIGS. 3a, 3b and 3c, namely an apparatus which can simultaneously withdraw two or more identical or different sheets from a dark box M or an analogous cassette or magazine for exposed but undeveloped photosensitive material.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of the above outlined contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.
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Discrete light sensitive exposed but undeveloped sheets which are stacked in a dark box are transferred toward or into one or more developing machines by one or more suction cups which can jointly attract a single sheet at a time or each of which can attract the uppermost sheet of one of two or more stacks of sheets in the dark box. A suction cup which attracts a portion of the uppermost sheet of a stack in the dark box is caused to flex the attracted portion above and away from the sheet below the uppermost sheet in order to promote separation of the uppermost sheet from the remainder of the stack. The flexed uppermost sheet is then at least partially extracted from the dark box and is monitored to ascertain whether or not its underside adheres to one or more sheets. If the at least partly extracted uppermost sheet carries or entrains one or more additional sheets, all extracted sheets are returned into the dark box and the procedure is started anew but the interval and/or the extent of flexing is increased to further reduce the likelihood of adherence of one or more sheets to the underside of the extracted uppermost sheet. A visible or audible signal is generated if a certain number of successive extractions of one and the same uppermost sheet still results in simultaneous extraction of two or more sheets.
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DESCRIPTION
1. Technical Field
This invention relates to elevator drive motors, in particular, geared elevator drive motors and, specifically, traction elevators employing elevator drive motors that use a worm gear.
2. Background Art
Geared elevator drives are very common. With few, if any, exceptions, geared elevator drives use a worm gear that engages a gear wheel that is attached to a shaft to which the elevator sheave is attached. The worm gear or worm as it is often called is rotated by an AC electrical motor, usually single or two speed, but, in some more recent systems, variable frequency AC to offer continuously variable motor speed control. The sheave, it is commonly known, engages the elevator ropes and usually supports the elevator car and counterweight, a considerable shaft load. In this "traction" elevator system, the traction between the rotating sheave and the rope propels the car.
Manufacture and assembly of geared elevator drives is notable in that it is expensive, complicated, and not always done in a way that maximizes longevity of the shaft bearings. Construction techniques have focused ostensibly on simplifying the insertion of the shaft and the wheel gear as a single subassembly in the motor housing or case, an objective that has led to the uniform use of two-piece gear housings or cases. Typically, the shaft subassembly with the bearings on the shaft is inserted into one gear case half. Semicircular bearing seats are milled into each half; these should be perfectly aligned with the shaft axis and should be perfectly circular because, when the two halves are joined, they form the bearing bore that supports each of the shaft bearings, of which there are two usually, one, just next to the sheave, the other, at the opposite end of the shaft. A seal is placed on the bottom of the case, and the two halves are bolted together. The two halves are separated to service the gear wheel and the worm. The vertical load on the shaft, which may be substantial, the combined weight of the cab and counterweight and ropes, exerts forces on the case that tends to distort the alignment of the two case halves. In reality, the stresses on the case halves or sections, is more complex than that because the load is entirely on one side of the shaft in all but a few geared traction elevators. The effect is that it is difficult to maintain precise bearing alignment over the life of the drive, which is typically many years, and the bearings may wear prematurely, creating annoying mechanical noise in the drive. Sometimes the stresses cause leaks in the case seal, allowing gear oil to escape.
DISCLOSURE OF INVENTION
An object of the present invention is to provide a far more reliable, durable type of geared elevator drive.
According to the present invention, the gear case is made of a single piece. An access port is provided on the side of the case to insert the gear wheel. The bearing bore or holes for the shaft ball bearings are drilled simultaneously, ensuring that the shaft bearings, when inserted, are coaxial.
According to the invention, the gear wheel is placed inside the case and then one end of the shaft inserted through one bearing hole towards the opposite bearing hole. The gear wheel is placed on the shaft. A ball bearing is inserted in the bore furthest from the shaft end that supports the sheave. A fitting on the end of the shaft is tightened to push the gear wheel onto the shaft by pushing the inner race of the bearing towards the gear wheel. The outer race of this bearing is pushed against a seat in the bearing bore by tightening a case cap that covers the bearing and the end of the shaft. The worm engages the gear wheel and is rotated to thread it down into a thrust bearing on the bottom of the case. A ball or roller bearing on the worm is held in place by a retainer or collar that is tightened (bolted) to the case from the top of the case with the motor removed.
Among the features of the present invention is that it allows for a very rapid assembly and disassembly of the motor; the bearings are optimally aligned and the alignment will not change; and the only gasket is for the access port, which does not sustain any loading.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an elevational view of a worm gear elevator drive of the "vertical type", the worm gear is vertical and the motor is on the top of the gear housing or case.
FIG. 2 is a sectional view of part of the gear case as seen from the same direction as in FIG. 1; it exposes the gear wheel, shaft, shaft bearing components and other parts inside the case.
FIG. 3 is a partial sectional view, as seen from the direction 3--3 in FIG. 1, and exposes the worm and its bearings and bearing retainer.
BEST MODE FOR CARRYING OUT THE INVENTION
As stated previously, FIG. 1 shows a "vertical" worm gear elevator drive motor. This drives contains a sheave 10 which is rotated by a motor 12 through a gear assembly (not visible) within a gear case 14. On the top of the motor 12 is a drum brake 16, simplistically shown being that it is commonly used in elevators. The operation of the brake is not germane to the invention; still it may be helpful to appreciate that a typical brake would have a drum that is bolted or otherwise attached to the motor shaft. The brake is operated when an elevator car is at a floor. Attached by a plurality of bolts to the case, a cover plate 16 closes access to the interior of the case. Assembly of the interior gear case components is conveniently made through the access provided when the plate is removed. Not shown, there is a gasket between the plate and the case.
The sheave has been deleted in FIG. 2, which shows the internal components within the case 14, among them a circular gear wheel 20. Several features need to be observed. The shaft 22 is tapered and contains a key 26. The gear wheel, of course, fits tightly onto the taper and has a slot to receive the key. As in many drives, the gear teeth 28 are attached to the outside of the gear wheel, which acts more like a hub on which a rim, containing the teeth, is attached. These teeth are engaged by a worm 30, which is also visible in FIG. 3. The worm 30 extends upward partially through the motor. By means of a plurality of bolts 31 that extend down through the brake, the motor shaft and the brake and the worm are mechanically connected together.
At the "sheave end" of the shaft 22, there is a ball bearing 32 that is held in place by a retainer ring 34. At the opposite end of the shaft, there is also a ball bearing 36. The bore holes for each of these ball bearings are on the same axis, that is, they are coaxial, having been machined by rotating the case or drilling the holes on a common axis.
Special attention should be given to the way in which the bearing 36 is installed in the case and also to its relationship to the gear wheel. The way it is installed makes it possible to "hand assemble" the wheel gear on the shaft within the case; final assembly is achieved by positioning and adjusting externally accessible components. The size of the access hole into the case is minimized as access for tools is not required. Specifically, the bearing 36 is lightly pushed into the bore around the shaft, but between the bearing 36 and the gear wheel 20 is a thrust ring 38. The inner race of the bearing 36 is pushed against the thrust ring 38 as a thrust plate 40 is "tightened down" onto the end of the shaft. This pushes the thrust ring against the gear wheel, forcing the gear wheel tightly on the tapered portion of the shaft. The outer race 36.1 of the bearing 36 is held in place by a cover plate 42, and it contains an inner flange 44. That flange fits snugly in the bearing bore or hole, and pushes the outer race 36.1 into its seat when the cover plate is tightened down with the bolts 45.
The gear teeth 28 are held on the gear wheel 20 by means of bolts. These bolts are not shown, but it should be understood that this type of attachment is common. However, access to the bolts is conveniently provided by removing the cover plate 42, exposing the holes 50, through which the bolts can be reached.
Assembly of the motor and, for that matter, disassembly and repair is especially convenient. Using the single piece case 14, that is, with the bore holes for the bearings coaxially and simultaneously machined, the gear 20 with the gear teeth 28 thereon is first inserted into the side of the machine through the space provided by the removed plate 15. Holding the gear wheel 20 in one hand, the installer then inserts the shaft 22 through the right side of the case, directing the tapered end and the keyhole through the interior of the gear wheel 20. Then the spacer ring 38 is slid over the end of the shaft, passing through the interior of the bore hole. It is placed lightly against the gear wheel 20. The bearing 36 is then placed over the end of the shaft within the bore hole, an action which, as stated before, forces the inner race against the retainer ring and thereby holds the gear wheel 20 securely in place on the shaft.
The worm is then separately installed from the top of the case 14 by rotating it so that it is "threaded down" by the wheel gear that it engages. As FIG. 3 shows, the worm is supported on two roller or ball bearings 56, 60. The bearing 56 rests in a seat 58 in the top of the case. The lower end of the worm 30 contains a narrow shaft area that fits into the bearing 60, a thrust roller or ball bearing. A retainer ring 64 is fastened in place onto the case, securing the bearing in place by pressing the outer race of the bearing into the seat 58. The worm contains a collar 70 which butts up against the inner race of the bearing 56. The worm 30 extends all the way up through the case. The motor, with the brake attached to the motor shaft, is installed on the case, and the motor shaft is attached to the worm. The worm 30 contains a key 72. The motor 14 drive shaft, which is not visible in the drawing, is hollow or tubular, a typical configuration, and the key registers with a keyway inside the shaft.
The assembly is finally completed when the motor is then bolted in place on top of the motor and the motor and brake shaft is secured through bolts 31 to the worm 30. Then the cover plate 15 and the gasket 15.1 between it and the case are then installed using bolts 14.1.
The foregoing is a description of the best mode for carrying out the invention, but it will be obvious to one skilled in the art that modifications and variations therein may be made in whole or in part without departing from the true scope and spirit of the invention.
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An elevator drive has an electric motor 12 which drives a worm 30 that drives a gear 20,28 on a shaft 22, at right angles to the worm 30. The output shaft is in the horizontal plane, and an elevator rope sheave 10 is attached to this shaft 22. The shaft 22 is mounted on two bearings 32,36, at opposite ends of a single piece case 14. The drive is assembled by first inserting the gear 20,28 through the side of the case 14, then inserting the shaft 22 through one end of the case through the gear 20,28 and into the bearing 36. Then a thrust plate 40 is tightened down on the end of the shaft 22 to hold the shaft in place on the bearing's inner race and also thrust the gear 20,28 onto the shaft 22. The worm 30 is then inserted through the top of the case 14. Both shaft support bearings 32,36 are machined on the same axis.
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BACKGROUND OF THE INVENTION
The present invention relates to the protection of an electrical circuit against overload and here particularly against excess currents.
Overload protection for an electrical circuit may be provided directly through a circuit breaker which includes an armature for operating one or several pairs of contacts, particularly indirectly through release of another spring while acting against a return spring, the latter being stronger than the former but the former provides the requisite contact pressure. Moreover, the circuit breaker includes a magnetic core having an axial bore which traverses and penetrates the core entirely which bore is, therefore, accessible from the side facing away from the armature. The circuit breaker of the type mentioned thus far is, for example, described in German printed patent application No. 24 18 930.
Usually, circuit breakers are operated in such a manner that the current in the energizing coil increases until attracting the armature so that the armature in turn can cause the contacts to be closed. Following the electromagnetic attraction, the holding current through the energizing coil is reduced particularly for purposes of saving current, which is highly desirable, for example, in case a circuit pertains to a railless vehicle receiving power from electric batteries. Therefore, these kind of circuit breakers function essentially as electromagnetically operated devices. Therefore, they require supplemental elements in order to provide full protection of the normally goverened by the circuit breaker circuit. Consequently, the space requirement is fairly large, which again is undesirable in case of mobile equipment such as battery powered vehicles or the like.
DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide a new and improved protective device in electric circuits, governed by circuit breakers for protecting the circuit proper against overload currents and having the same degree of operative certainty and safety of operation as the prior art devices but being provided in a more compact design.
It is a particular object of the present invention to provide overload protection in an electric circuit being governed by an electromagnetically operated circuit breaker with spring bias and multiple contact operation.
In accordance with the preferred embodiment of the present invention, it is suggested to provide a supplemental or auxiliary electromagnetic system being coaxial to a bore in the core of the circuit breaker as per this particular object which supplemental electromagnet systeme has a coil being passed through by electric current whenever the circuit breaker has responded; the armature of this supplemental electromagnet is to move opposite the direction of movement of the armature of the circuit breaker and the core of the auxiliary electromagnet is to be provided with a bore which is aligned with the bore of the core of the circuit breaker; the air gap of the auxiliary electromagnet is to be sufficiently large so that current flowing through under normal operations (no overload) will not cause the armature to be attracted. Only overload current in the principal circuit will provide such attraction; moreover, the two bores are penetrated by a common plunger or rod which is affixed to the armature of the supplemental or auxiliary electromagnet. The plunger or rod is dimensioned so that in case of no energization of the supplemental electromagnet under conditions of energization of the circuit breaker, the rod or plunger is spaced from the armature of the circuit breaker at a distance smaller than the lifting stroke of the armature of auxiliary and supplemental electromagnet.
DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects and features of the invention and futher objects, features and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a somewhat schematic section view through a circuit breaker with supplemental electromagnet as per the preferred embodiment of the present invention for practicing the best mode thereof; and
FIG. 2 is a somewhat schematic modification of the structure shown in FIG. 1 still constituting a preferred embodiment of the invention.
Proceeding now to the detailed description of the drawing, FIG. 1 illustrates a regular circuit breaker with plunger type armature and denoted generally as a group of elements 1. Basically, the circuit breaker includes a coil 2 on a coil carrier 2a surrounding a magnetic core 3 holding through the dotted yoke 4 the pole ring 5. The other end of the core 3 carries directly a pole ring 6. The circuit breaker 1 is shown in operating position, i.e. after response to a normal operating command. This means in particular that the coil 2 is flown through by a holding current so that an armature 7 of the circuit breaker has been attracted into the gap space delineated by pole ring 5 as well as by the axial end 3a of core 3. In fact, then, the armature 7 is retracted generally into the coil core system against the force of a spring 8. Armature 7 carries coaxially an operating plunger 12.
In the disposition as illustrated plunger 12, armature 7 though retracted releases a spring 30 which is generally weaker than the restricting spring 8 but establishes the contact pressure by means of which a contact bridge 9 rests on stationary contacts 10 and 11. Plunger 12 is disengaged from bridge 9.
The return spring 8 is partially inserted in a blind bore 13 of the armature 7. The other end of return spring 8 bears against a shoulder 14 which establishes a widening within the core from a relatively small diameter bore 15 to a larger diameter bore 15a which is in alignment with the blind bore 13. The central bore 15 penetrates the core 3 in its entirety and establishes so to speak the basic axis of the system, details thereof will be described below.
Having thus far described the basic circuit breaker configuration, reference is made now to a supplemental and auxiliary electromagnet or, better, electromagnet system generally designated by reference numeral 16. This electromagnet system includes a magnet core 17 with a yoke 18 and pole rings 19 and 20. The electromagnet system furthermore includes a coil 21 which is comprised of relatively few windings. This coil 21 is electrically connected to the contact system 9, 10 and 11 of the circuit breaker 1. In other words coil 21 receives a small bypass current from the load current through the circuit and the contacts 9, 10, and 11.
The core 17 of the auxiliary electromagnet system 16 includes likewise a bore 22 which traverses the core 17 in its entirety. Moreover, the elements are mounted in relation to each other such that the bore 22 is axially aligned with the bore 15 of the magnet core 3 of circuit breaker 1.
The auxiliary magnet system 16 furthermore includes a plunger type armature 23 which assumes the position as illustrated in FIG. 1 whenever the magnet system 16 is not energized. This armature 23 is now affixed to a plunger or rod 24 penetrating the bores 22 and 15 as well as the spring 8. The plunger or rod 24 has a particular length which is defined as follows. As stated, the auxiliary electromagnetic system 16 is in the unenergized state as per FIG. 1 while the circuit breaker 1 is energized. This then establishes a particular disposition of the plunger or rod 24 in relation to the armature 7 of the energized circuit breaker (as in gap 26). This disposition in turn establishes a distance 25 between the plunger or rod 24 and the armature 7. This particular distance 25 is smaller than the lifting stroke 26 imparted by the magnet system 16 upon its armature 23. The rod 24, of course, is affixed to the armature 23 so that the distance and space relations are directly related and relatable to each other.
As the current through the contact system 9, 10 and 11 increases the current through the coil 21 of the magnet system 16 increases likewise. If the permissable magnitude of that current is exceeded the coil 21 will energize the system 16 such that the armature 23 is attracted to the core 17. Since, as stated, the lifting stroke 26 of the armature 23 as so attracted is larger than the distance 25 of the plunger 24 from the armature 7, and since the relationships of movement are in opposition to each other and since the armature 7 is held by the spring 8, the following transpires.
The plunger 24 will necessarily impact upon the armature 7 and will drive the armature 7 from its illustrated disposition. This means that the actuating plunger 12 pushes against the contact bridge 9 and opens the circuit connection between the contact 10 and 11. One can see that for reasons of proper mechanical force transmission, plunger 24 should be coaxial with plunger 12.
In order to adjust the sensitivity of the auxiliary magnet system 16, it is suggested to vary the length insertion of the plunger 24 into the armature 23, for example, by means of a screw connection 27 or otherwise. This, in effect, adjusts the distance 25 which the tip of the plunger 24 has to traverse before impacting upon the armature 7.
The inventive concept is applicable also to a pivot armature type of circuit breaker. The various elements shown in FIG. 2 are quite similar to those shown in FIG. 1 which includes particularly the construction of the circuit breaker. The difference, however, resides in the employment of pivot armatures 28 and 29 for the circuit breaker 1 and the auxiliary system 16 respectively. In other words, the difference can be seen in that rather than providing mere lifting of the contact bridge 9, pivot motion is introduced but involves still axial plunger movement as described.
The invention is not limited to the embodiments described above but all changes and modifications thereof not constituting departures from the spirit and scope of the invention are intended to be included.
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A particular overload protection is provided for a circuit which is normally closed by an electromagnetic circuit breaker energized by a relatively low level holding current. The overload protection is particularly provided through an auxiliary electromagnetic system connected to be responsive to the current in the circuit governed by the circuit breaker whereby the auxiliary electromagnetic system includes an armature carrying a plunger penetrating the circuit breaker such that upon occurence of an overload the auxiliary electromagnetic system is energized and its plunger pushes the armature of the circuit breaker into a contact opening disposition.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to toilet bowl devices and more particularly to an auxiliary water flow structure for producing a laminar flow sheet on the bowl surface that is rendered operative in conjunction with the articulation of the toilet seat.
2. Description of the Prior Art
In a typical household there are few physical structures that accommodate or distinguish between the male and female anatomy of the occupants, the accommodation of the anatomical differences being mostly focused in the structure of a toilet. To resolve this differentiation in use the typical household toilet includes a pivoted seat that is often manually raised by the male as a courtesy to those that may follow, thus moving the seat surface away from any incident backsplash. The articulated seat, however, is then frequently left in its upright position and this inattention, itself, often rises to the level of a constant irritant and a source of dispute.
In the past various devices have been proposed which in one way or another lower the toilet seat after a time period expires after it has been raised. Examples of such devices can be found in the teachings of U.S. Pat. No. 5,488,744 to Paananen; U.S. Pat. No. 5,742,949 to Golgi, et al.; U.S. Pat. No. 6,035,454 to Birchall; and others. While suitable in resolving these pervasive inattention disputes, and thus for the purposes intended, these teachings do not address, nor do they contemplate, the other subsidiary household disputes about those parts of the backsplash that fall outside the confines of the toilet bowl. Simply, the statistical distribution of splashing during the course of male urination extends beyond the toilet bowl periphery and the articulated seat courtesy therefore attends to only one part of the problem. Also needed are techniques and devices that modify backsplash kinematics to the confines of the bowl. Devices that concurrently control the backsplash trajectory while also automatically attending to the seat lowering courtesy are therefore extensively desired and it is one such device that is disclosed herein.
SUMMARY OF THE INVENTION
Accordingly, it is the general purpose and object of the present invention to provide a seat lowering mechanism effected by a water stream that also produces a laminar flow over the interior surfaces of a toilet bowl.
Other objects of the invention are to provide a hydraulic actuator for an articulated toilet seat that also produces a laminar fluid flow sheet on the surfaces of a toilet bowl.
Further objects of the invention are to provide a water flow operated toilet seat lowering device which also is useful to produce a laminar flow over the interior bowl surfaces.
Yet additional objects of the invention are to provide an structure for producing a backsplash controlling surface flow in a toilet bowl that cooperates with an automated sequence of seat lowering.
Briefly, these and other objects are accomplished within the present invention by providing an air filled bellows spring mounted to oppose the articulation of a toilet seat, the bellows spring being connected with, and forming a common cavity with, the vacuum chamber of a conventional delay valve also mounted to be initiated by the pivoting of the seat. Thus once the seat is raised the resulting flow through the delay valve creates a partial vacuum therein, latching the delay valve to an open (on) state and also latching the bellows spring to its pulled in position. In this state the flow output from the delay valve is directed through an exit port aligned along the interior bowl surface, forming a laminar flow surface that modifies the net rebound kinematics of any flow associated with male urination. When, however, this water flow ends by the vacuum breaking timing mechanism customarily provided the spring bellows is free to vent releasing its opposing bias to displace the seat from its vertical equilibrium which then allows the seat to drop against the spring bias of two balance springs that control the seat return articulation.
Preferably, the delay period of the delay valve is selected to span a time interval that is greater than the typical interval of male urination, e.g., a minute or less, during which the water flow is directed tangentially onto the bowl surface to create a circular flow sheet therein. This circulating water flow sheet provides a tangential velocity component to any urination stream that may merge therewith, thereby limiting the kinematics of any backsplash to a dominantly tangential path. The circulating flow sheet, moreover, assists in maintaining a high level of cleanliness within the bowl thus further enhancing the utility of the instant invention These functions can be conveniently implemented by commercially available devices with the lifting articulation of the seat providing the necessary sequence initiation.
Those skilled in the art will appreciate that the circulation in a toilet bowl includes a component that is determined by the rotation of the Earth. Water conservation interests, in turn, require that the sheet flow be minimized. To optimize the benefit of the laminar sheet flow the tangential velocity thereof can be enhanced by selecting the exit flow alignment according to each hemisphere, conveniently effected by selecting the direction of a pivotal exit port in the form of a convolved exit pipe segment that is releasably connected to the delay valve. In this manner the orientation selection of a single element is utilized to expand the utility of the whole assembly.
It will be appreciated that toilet bowls with very little exception include an interior surface that promotes good surface flows towards the drain opening. This geometry compensates for the drag losses of the laminar sheet flow developed herein and as the flow rates drop off due to surface expansion the loss is then compensated by the gravitational effects. A simple, low volume water flow source is thus rendered effective over the whole of the bowl surface to alter the backsplash trajectory throughout the bowl.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective illustration, separated by parts, of a conventional toilet seat provided with the inventive water flow system rendered operative by the articulation thereof;
FIG. 2 is yet another perspective illustration of a toilet bowl implemented with the inventive water flow system described herein;
FIG. 3 is a diagrammatic illustration of the water flow system in accordance with the present invention;
FIG. 4 is a vector diagram illustrating the energy vector contribution to the net reflected vector from the sheet water flow in accordance with the present invention;
FIG. 5 is a side view detail of the toilet bowl implemented with the inventive water flow system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1-5, the inventive water flow system, generally designated by the numeral 10 , comprises a conventional toilet bowl TB provided with its flushing reservoir FR supplied with pressurized water from a wall (or floor) mounted water outlet WO. In typical practice toilet bowl TB is further provided with a pivotally mounted seat PS mounted on a hinge or pivot assembly PA at the rear of the bowl opening adjacent the reservoir FR. It is this seat PS that is usually raised to a vertical alignment adjacent the reservoir by the male user of the toilet during urination, and while this courtesy is often practiced lowering the seat is less than consistent along with the inherent rebound dynamics of the stream that often cause unwanted splatter outside the confines of the toilet bowl. It is these two courtesies that are resolved herein.
More precisely, the inventive water flow system 10 is conformed as an aftermarket installation to be mounted on an offset bracket or strap 11 conformed to match the fastener pattern of the seat pivot assembly PA and is thus fixed in a sandwiched arrangement between the pivot assembly PA and the corresponding toilet bowl surface. In this position offset bracket 11 is useful to mount a bellows spring 12 and a conventional delay valve 25 next to each other, in a vertical alignment subjacent the plane of the pivotally lifted toilet seat PS. At the same time an angled piece 15 is secured to the underside of seat PS, again along and adjacent the pivot assembly PA, to pivotally advance a cantilevered panel 16 against the bellows spring 12 and the manual selector 26 usually provided with delay valve 25 to set off its operation, the selector 26 being thus aligned for articulation when the seat is lifted. Of course, adjustment is provided to effect these pivotal contacts only when the seat is raised beyond its vertical position, by way of slotted fastener openings 15 a in the angled piece 15 and also by adjustable mountings 11 a and 11 b attaching the bellows spring 12 and the delay valve 25 and by slotting the pivot assembly openings 11 c in bracket 11 as well. Additionally a set of helical helper springs 21 a and 21 b is installed at both the pivots of pivot assembly PA to oppose the return motion of the seat.
Those skilled in the art will appreciate that while in small variations conventional delay valves may be variously implemented the typical configuration of delay valve 25 , like that sold by the Sloan Company under the model or style ‘Flushometer’ or that sold by the China Winds Group under the model no 3812, is characterized by a flow control chamber 27 connected to the water outlet WO and controlled either by the vacuum displacement of a diaphragm 28 or by the selector 26 to open the water flow passage through a venturi 29 . Once this flow starts the lower venturi pressure pulls a partial vacuum in a vacuum chamber 31 to displace diaphragm 28 and thereby latch the valve to its open state. A controllable part of the flow is then diverted to a vacuum breaker chamber 32 and it is this diverted flow rate that determines the duration of the flow.
In accordance with the present invention the foregoing conventional delay valve is modified to include a port in the vacuum chamber 31 to which a tubing segment 22 is connected, segment 22 communicating at its other end with bellows spring 12 . Thus once the seat PS is lifted to its over-center position, depressing bellows spring 12 and at the end articulating selector 26 , the vacuum drawn in the common cavities below diaphragm 28 and bellows spring 12 keeps the spring pulled in until the delay limit is reached and the vacuum is broken. At that point the interior of the bellows is vented through the venturi 29 to atmospheric pressure, pushing seat PS back across its neutral point from where it then falls against the opposing springs 21 a and 21 b . In this manner a timed stream of water is provided while the seat is upright which, on its termination, initiates the lowering of the seal This stream of water may be directed into the interior of bowl TB by way of a further tubing segment 41 connected to the outlet of the venturi 29 and convolved to pass under seat PS into the bowl interior where the tubing end is collapsed to form a transverse end slot 42 that is tangentially aligned along the interior bowl surface.
Those skilled in the art will appreciate that the foregoing assembly may be easily installed onto existing toilet structures with minimal modifications. For example, the water source itself may be obtained from a tee connection 46 installed into the conventionally provided conveyance tube CT extending from the outlet WO to the reservoir and two forms of the tubing segment 41 may be provided to accommodate use in both the Northern and Southern hemispheres. The triggering point of the selector 26 can similarly be adjusted to be just beyond the upright seat alignment, thereby accommodating various seat structures and weights.
In this manner a laminar flow sheet is formed over the interior surfaces of the toilet bowl which both cleans the surfaces and also produces a gradient of flow vectors FV 1 through FVn that are all tangential to the local surface in a descending spiral towards the bottom of the bowl. Referring in particular to FIG. 4 the normal rebound angle RA shown as a set of vectors RV 1 through RVm are each substantially equal, but opposite, to the incidence angle IA of the urination stream US and with some frequency the rebound trajectories resulting from vectors RV 1 -RVm extend beyond the bowl. This rebound pattern is inventively modified herein by the addition of the flow vectors FV 1 -FVn and by a simple adjustment of a control valve 45 on the conveyance tube CT the level of this laminar flow can be raised to a point where virtually all backsplash is eliminated. In this manner a conveniently mounted modification is obtained which eliminates virtually all arguments concerning the courtesies of shared toiled use.
Obviously, many modifications and variations can be effected without departing from the spirit of the invention instantly taught It is therefore intended that the scope of the invention be determined solely by the claims appended hereto.
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An assembly useful in directing a stream of water onto the surfaces of a toilet bowl includes a delay valve rendered operative by the lifting of the toilet seat and a bellows spring connected to be pulled in by the latching vacuum draw of the delay valve and thereafter released to displace the seat towards its lowered state. A set of springs then opposes the dropping stroke of the seat once displaced by the bellows spring. The assembly is conformed for installation onto an existing toilet.
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FIELD OF THE INVENTION
This invention relates to high power linear amplifiers and more particularly to automatic control systems employing feed forward circuitry to reduce amplifier distortion. It relates particularly to adjusting gain and phase of the feed forward circuitry.
BACKGROUND OF THE INVENTION
RF linear amplifiers utilize devices that exhibit non-linear characteristics at higher power levels thereby resulting in the introduction of signal distortions. If more than one signal is applied to a linear amplifier, its non-linear characteristics cause an unwanted multiplicative interaction of the signals being amplified and the amplifier output contains intermodulation products. These intermodulation products cause interference and crosstalk over the amplifier frequency operating range which interference may exceed established transmission standards.
As is well known, intermodulation distortion can be reduced by negative feedback of the distortion components, predistorian of the signal to be amplified to cancel the amplifier generated distortion or by separating the distortion component of the amplifier output and feeding forward the distortion component to cancel the distortion in the amplifier output signal. Of these techniques, the forward feed approach provides the most improvement. Forward feed, however, is the most difficult to apply since it requires modifying the separated distortion component in amplitude and phase to match the gain and phase shift of the amplifier on a continuous basis.
U.S. Pat. No. 4,885,551 (assigned to same assignee as this application) discloses a linear amplifier having a feed forward circuit used for cancellation of distortion in the amplification circuitry. To accomplish this cancellation operation, adjustment of amplitude and phase parameters of the feed forward circuit is performed by a stored program controller. Adjustement in the gain and phase of the feed forward path is made by comparing a carrier detected signal amplitude to a previous signal amplitude and selecting one of three step size adjustments for further adjustment depending on a calculated DB level representing the difference.
SUMMARY OF THE INVENTION
A linear amplifier includes a feed forward circuit operative to eliminate distortion of the amplified signal by utilizing a second circuit path parallel to the amplification path to transfer the input signal without distortion and combine it with the output of the amplification path to form a signal representative of the distortion in the amplification path. Its amplitude and phase is modified so that it may be subtracted from the output of the amplification path to cancel the distortion component. The gain and phase of the feed forward circuit is automatically adjusted by sequential discrete steps through the operation of a stored program controller. The initial adjustment step is set at some minimum discrete value and its effect on the cancellation level of the feed forward circuit is evaluated. If the cancellation level does not change by a specified amount the adjustment step is increased by a discrete amount. The effects of this new adjustment step on the cancellation level is evaluated again. This continues unitl the cancellation level changes by more than the specified amount or the number of times the adjustment step has increased exceeds a present value. Adjustment of the cancellation level is continued by discrete steps under control of the stored program control until a desired cancellation level is achieved. If the maximum step adjustments fails to achieve the desired response, the stored program control checks for the existence of possible fault conditions in the feed forward circuit.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a general block diagram of an amplifier using a carrier signal for forward feed distortion correction;
FIG. 2 shows a more detailed diagram of the controller used in the circuit of FIG. 1;
FIGS. 3, 4 and 5 are flow charts illustrating the operation of the controller for the amplifier of FIG. 1;
FIG. 6 shows waveforms illustrating the operation of the circuit of FIG. 1 in the amplifier frequency spectrum.
DETAILED DESCRIPTION
FIG. 1 depicts a forward feed amplifier that is operative to amplify signals across a prescribed frequency band. Referring to FIG. 1, a composite input signal which may comprise a plurality of signals across the prescribed band is divided into two portions s 1 and s 2 by directional coupler 101. The amplitude and phase of signal s 1 is modified in amplitude and phase adjuster 105, amplified in main amplifier 110, and directed to the output 132 through directional coupler 113, delay 119, directional couplers 127 and 130. Distortion and intermodulation product components may be added by power amplifier 110 as aforementioned which distortion must be removed from the signal appearing at output 132.
Signal s 2 is delayed in delay circuit 103 and applied to one input of cancellation circuit 115 without any distortion being introduced. Directional coupler 113 splits the signal from power amplifier 110 and supplies a portion of the power amplifier output to the other input of cancellation circuit 115. The signal from directional coupler 113 has a distortion and intermodulation product component but the signal from delay 103 is clean i.e., substantially free of any distortion. The clean signal from delay 103 is subtracted from the distorted amplifier output signal in cancellation circuit 115. If the amplitude and phase of the power amplifier input is properly adjusted, the amplified signal from the directional coupler 113 is cancelled by the clean signal from delay 103. As a result, only the distortion and intermodulation component appears at the cancellation circuit output.
A portion of the distortion component from cancellation circuit 115 is passed through signal splitter 117, amplitude and phase adjuster 122 and correction amplifier 124 into directional coupler 127 wherein it is subtracted from the output of the power amplifier applied via directional coupler 113 and delay 119. The time delay of delay 119 is set to compensate for the signal delay through the path including signal splitter 117, amplitude and phase adjuster 122 and auxiliary amplifier 124. Consequently, the output signal from directional coupler 127 has all or a substantial portion of the distortion from the power amplifier removed.
In order to assure maximum distortion removal, the distortion signal must be measured and amplitude and phase adjusters controlled to reduce the distortion. FIG. 6 illustrates the frequency band of the circuit of FIG. 1. Carrier signals shown in waveforms 701, 703 and 705 have amplitudes greater than -30 db and an intermodulation distortion product signal 707 has an amplitude between -30 and -60 db. In accordance with the invention, controller 140 is operative to scan output 132 from one end, e.g., f L , of the prescribed frequency band of the circuit of FIG. 1 to locate carrier signal S c (waveform 701). Once the carrier signal is located, the magnitude of the carrier signal from cancellation circuit 115 is supplied to the controller via narrow band receiver 150 and the amplitude and phase parameters of amplitude and phase corrector 105 are iteratively modified by the controller to drive the carrier signal component of the output of the cancellation circuit to a minimum. This amplitude and phase adjustment assures that output of the cancellation circuit has the maximum carrier signal reduction. It is also necessary to minimize the intermodulation product component of the power amplifier output. In accordance with the invention, the prescribed frequency band is again scanned from end f L in FIG. 6 to detect the intermodulation product signal of waveform 707. Once the intermodulation product signal is found, the parameters of amplitude and phase adjuster 122 are iteratively modified by controller 140 to minimize the intermodulation product signal appearing on lead 134 from directional coupler 130. Advantageously, it is not necessary to remove a portion of the prescribed frequency band from service in order to insert a pilot signal for distortion reduction.
Controller 140 is shown in greater detail in FIG. 2. The circuit of FIG. 2 comprises a signal processor arrangement such as the Intel type D87C51 microprocessor and includes control program store 305, control processor 310, carrier and intermodulation signal store 315, input interface 303, output interface 335 and bus 318. Analog-to-digital converter 301 receives signals representative of the magnitude of signals from receiver 150 and converts the analog signal into a series of digital values. Control processor 310 operating in accordance with instructions stored in control program store 305 causes these digital values to be sent to store 315 via input interface 303 and bus 318. The processor also provides digital signals to digital-to-analog converters 320, 325, 330, 340, and 345 via bus 318 and output interface 335. The analog output of converter 320 is supplied to voltage controlled oscillator (VCO) 142 to direct scanning operations. The output of converters 325 and 330 are sent to the amplitude adjustment control and the phase adjustment control of amplitude and phase adjuster 105 via leads 153 and 155 to modify the adjuster's amplitude and phase characteristics, respectively. The outputs of converters 340 and 345 are sent to amplitude and phase adjuster 122 via leads 157 and 159 to modify its amplitude and phase parameters. Interface 335 is also connected to the control lead of RF switch 137 to determine its position during the control operations.
Prior to the start of operation of the circuit of FIG. 1, amplitude and phase adjusters 105 and 122 are manually trimmed to optimum settings. Controller 140 is adapted to maintain optimum operation over time under varying conditions. Amplitude and phase adjuster 105 modifies the amplitude and phase characteristics of the circuit path including power amplifier 110 so that the amplifier output signal is cancelled by the undistorted input signal from delay 103. Controller 140 is first connected to directional coupler 130 by RF switch 137 and directs the scanning of the frequency spectrum of the signal therefrom through VCO 142, mixer 145 and narrow band receiver 150 in FIG. 1 to detect a carrier. It is then connected to splitter 117 at the output of cancellation circuit 115 and the amplitude and phase parameters of adjuster 105 are adjusted to minimize the magnitude of the carrier appearing on lead 165. After the carrier component is minimized or a preset number of adjustments are made, the controller operates to scan the prescribed frequency band from end f L on lead 134 to detect an intermodulation signal and makes a sequence of adjustments of the amplitude and phase parameters of adjuster 122 to reduce the intermodulation signal on lead 134 below a prescribed threshold. The controller continuously cycles through parameter adjustment of amplitude and phase adjusters 105 and 122.
The operation of the controller of FIG. 2 is directed by instructions permanently stored in control program store 305. FIG. 3 is a flow chart illustrating the operation of the controller 140 in accordance with the instructions stored therein. With reference to FIGS. 2 and 3, control processor 310 initially resets digital to analog converters 320, 325, 330, 340 and 345 as per program step 401. Carrier adjustment control signals and the intermodulation adjustment control signals are the initialized in steps 402 and 403 and RF switch 137 is set to receive the signal on lead 134 (step 404). At this time, VCO circuit 142 is set by digital-to-analog converter 320 to be at the f L end of the prescribed frequency range of the amplifier. RF switch 137 is set to couple lead 134 to one input of mixer 145 and VCO 142 is coupled to the other input of mixer 145. In the loop from step 405 to step 407, the prescribed frequency band is scanned (step 405) until a carrier signal is detected at lead 134 (step 407). Signals obtained at narrow band receiver 150 during the scan are applied to analog-to-digital converter 301 in FIG. 3 and stored by the control processor in data store 315. Upon detection of a carrier signal by the control processor, the carrier signal amplitude and frequency are stored and the scan frequency of VCO 142 is maintained (step 410).
Processor 310 sends a signal to RF Switch 137 to change its position to couple the distortion signal from splitter 117 to mixer 145 (step 412). At this time, the signal on lead 165 corresponding to the detected carrier is applied from receiver 150 to analog to digital converter 301. A signal N which counts the number of carrier signal adjustments is then set to one (step 415). The carrier magnitude M(Sc) is acquired (step 416) and it is assigned the designation M(Sc)*(step 418). The carrier signal adjustement loop from step 417 to step 430 is entered. During the iterative detected carrier signal adjustment, the parameters of amplitude and phase adjuster 105 are modified to minimize the carrier signal observed by the control processor. The loop is iterated until the carrier signal falls below a predetermined threshold or until a preset number of adjustments have been made.
In the carrier adjustment loop, the carrier signal at splitter 117 is applied to analog-to-digital converter 301 via RF switch 137, mixer 145 and receiver 150. The carrier magnitude data is analyzed and adjustments are made to the amplitude and phase parameters of adjuster 105 (step 417). The magnitude of the carrier signal M(S c ) is compared to the predetermined threshold in decision step 420 by processor 310. Until the carrier magnitude is less than the threshold TH, the loop is iterated. In each iteration, the magnitude of the carrier signal from splitter 117 is compared to a threshold value (step 420). If the magnitude of the carrier signal at splitter 117 is less than the threshold value, e.g., -30 db, the carrier component in the output of cancellation circuit 115 in FIG. 1 is determined to be acceptable, control is passed to step 433 and the intermodulation signal reduction is started. Where the magnitude is equal to or greater than the threshold value TH, the carrier adjustment count is incremented (step 427) and compared to a predetermined number N* (step 430). If N* is exceeded, the iterations are terminated and the intermodulation product signal reduction is begun in step 433. The operations of data analysis step 417 are shown in greater detail in the flow chart of FIG. 4.
The flow process of FIG. 4 is entered from step 415 or step 430 of the flow chart shown in FIG. 3. The flow process of FIG. 4 determines the level of adjustment of the amplitude and phase parameter of adjuster 105. Step 500 presets a step size of adjustment by setting a step size signal to some minimum value. Decision step 501 is invoked to determine whether the amplitude or phase parameter is to be adjusted in the current iteration. This is done by dividing the adjustment count signal N by 10. If the result is even, the control signals DR and CN are set to the amplitude adjustment values DRA and CNA in step 505. Otherwise, the adjustement control signals DR and CN are set to DRP and CNP for phase adjustment in step 510. Assume for purposes of illustration that amplitude adjustment is selected. The direction of charge control signal DR is initially set to the value, i.e., I (increase) or D (decrease), obtained in the last iteration. The condition control signal is set to either B (better) or W (worse) corresponding the corrective value of the last iteration.
Decision step 515 is then entered in which the control parameters are evaluated. If CN=B and DR=I or CN=W and DR=D indicating an improvement on increase or a worsening on decrease during the last iteration, control signal Dr is set to I and the control voltage on amplitude adjustment digital-to-analog converter 325 is increased by an amount corresponding to the initial setting of step size signal SS (step 525). In the event that the condition CN=B and DR=I or CN=W and DR=D is not satisfied, direction control DR is set to D and the control voltage on the amplitude adjustment converter is decreased by the amount corresponding to the last quantum step size SS (step 520).
After the adjustement of step 520 or step 525, the carrier detected signal amplitude M(Sc) is input from receiver 150 of FIG. 1 (step 530) and subtracted from the amplitude of the preceding iteration M(Sc)*(step 531) and compared to a value C. If the difference value is not greater than the value of C the step size is incremented by an amount d (step 542) and a counter recording the number of step adjustments n is incremental by 1. The count n is compared with a value K limiting the number of step adjustment (decision step 543). If the allowable number of step adjustments has been attained a check is made for the occurrence of a fault in the amplifier (step 544). Otherwise, the control flow signal is readjusted with the new step size. The readjustment of the control signal is accomlished by checking the DR flag (step 546). The control voltage is increased if DR=I and decreased if DR=D.
If the difference calculated in step 531 with or without the step size enlargement exceeds the present value C, the step adjusted signal is compared to the preceding iteration M(Sc)*(step 533). If M(Sc)≧M(sc)* the adjustment status is considered to have deteriorated and condition signal CN is set to W (step 538). Where M(Sc) is smaller than M(Sc)* this adjustment status is better and condition signal CN is set to B. M(Sc)* is then set to the current magnitude value M(Sc) in step 540 in preparation for the next iteration. The process continues, to step 560, which stores the value M(Sc). If N/10 is even for amplitude adjustment, step 564 is entered via decision step 560 and the updated parameters DR and CN are stored as signals DRA and CNA. If N/10 is odd, control parameters DR, CN and SS are stored as signals DRP and CNP in step 562. Processor control is then passed to step 420 in FIG. 4.
Where are signal N/10 is odd, the operation of the control processor is the same as previously described with respect to FIG. 4 except that condition control signal CNP and direction control signal DRP are obtained as indicated in step 510 and used as control signals CN and DR (Step 562). Processor control is then passed to step 420 in FIG. 3.
When the carrier processing loop of FIG. 3 is exited via decision step 420 or 430, processor 310 causes RF switch 137 to be repositioned so that lead 134 from directional coupler 130 is connected to one input of mixer 145 and the output of receiver 150 corresponds to the output signal at lead 134 (step 433). The controller is then conditioned to scan the frequency range of the amplifier from the same end used as the starting frequency of the carrier signal to search for an intermodulation product signal, e.g., signal between -30 db and +60 db (step 435). If such an intermodulation product signal is detected in step 440, the intermodulation count signal M is set to one (step 443). The intermodulation product amplitude is acquired and set to IM* (steps 444 and 446). Intermodulation adjustment loop from step 445 to step 455 is entered. Otherwise, the processor returns to step 404 so that the carrier scan process of steps 405 and 407 is restarted. In the intermodulation reduction loop, processor 310 analyzes the intermodulation signal magnitude IM and adjusts the amplitude and phase of adjuster 122 responsive thereto (step 445). After an adjustment is made to adjuster 122, the intermodulation signal IM is tested in decision step 448. If the magnitude IM is not between -30 and -60 db, processor control is passed to step 404 and the carrier signal search loop is reentered. When the IM signal is between -30 and -60 pl db, another iteration of the intermodulation reduction loop is needed and intermodulation count signal M is incremented (step 452). The incremented value is compared to maximum count signal M* (step 455) and the loop is reentered in step 445. If the magnitude IM is greater than -30 db, the detected signal may not be an intermodulation signal and control is returned to step 404. Where IM is below -60 db, the value is acceptable and step 404 is reentered. The intermodulation reduction loop may be exited from either decision steps 448 or 455.
The intermodulation signal analysis and adjustment step 445 is shown in greater detail in FIG. 5. Referring to FIG. 5, the analysis involves separate adjustment of the amplitude and phase parameters of adjuster 122. The flow process of FIG. 5 is entered into from step 443 or 455 in FIG. 3 in order to determine the adjustment of an amplitude or phase parameter. The adjustment step size is preset to some minimum value in step 600 and a count variable n is set to zero. Decision step 601 is operative to determine whether the amplitude or the phase parameter is to be adjusted in the current iteration. This is done by dividing the adjustment count signal M by 10. If the result is even, the control signals for the adjustments DR and CN, are set to previous intermodulation values DRIA and CNIA in step 605. Otherwise the adjustment control signals DR and CN, are set to previous intermodulation values DRIP and CNIP in step 610. Assume for purposes of illustration that amplitude adjustment is selected. The direction of change control signal DR is initially set to the value, i.e., I (increase) or D (decrease), obtained in the last iteration. The condition signal is set to either B (better) or W (worse) corresponding the corrective value of the last iteration.
Decision step 615 is then entered wherein the control parameters are evaluated. If CN=B and DR=I or CN=W and DR=D indicating an improvement on increase or a worsening on decrease during the last iteration, control signal DR is set to I and the control voltage on amplitude adjustment digital-to-analog converter 340 is increased by an amount corresponding to the setting of step size signal SS (step 625). In the event that the conditions CN=B and DR=I or CN=W and DR=D is not satisfied, direction control DR is set to D and the control voltage on the amplitude adjustment converter is decreased by the amount corresponding to the last iteration step size SS (step 620).
After the adjustment of step 620 or step 625, the intermodulation signal amplitude IM is input from receiver 150 of FIG. 1 (step 630) and compared to the amplitude of the preceding iteration IM* (step 631).
If the difference value is less than C then step size SS is incremented by the value d (step 642) and a counter recording the number of step adjustments n is incremented by 1 (step 642). The count n is compared with a limit value k (step 643) to limit the number of permissible adjustments. If the limit k has been reached, a check is made for the occurrence of a fault in the amplifier (step 644). If further step adjustments are required, the control signal is readjusted with the new step size. The readjustment of the control signal is implemented by checking the DR value (step 646). If DR=I, the control voltage is increased and if DR=W the control voltage is decreased.
If the difference value calculated in step 631 with or without the step size enlargement exceeds the preset value C the step adjustment signal is compared to the preceding iteration IM* (step 633). If IM ≧IM* the adjustment status is concluded to have deteriorated and condition signal CN is set to W (step 638). Where IM is smaller than IM* the adjustement status is considered good and a condition signal CN is set to B (step 638). IM* is then set to the current magnitude value IM in step 640 in preparation for the next iteration. The process continues to step 660.
Where the signal M/10 is odd, the operation of the control processor is the same as previously described with respect to FIG. 6 except that condition control signal CNIP and direction control signal DRIP are obtained as indicated in step 610 and used as control signals CN and DR. Maximum adjustment count signal M* may be set to a value such as 10 so that the control processor adjusts one of the amplitude and phase parameters of adjuster 105 ten times and then adjusts the other of the amplitude and phase parameters 10 times or until the conditions of step 448 are met.
When the data analysis and comparison of steps 445 and 448 are completed, intermodulation count M is incremented (step 452) and the count is compared to the maximum allowable count M(Sc)* in decision step 455. If M>M*, step 403 is reentered to begin the carrier signal search operations. Where M≦M* in step 455, the next iteration is then started in step 445. The iterations are ended when the intermodulation product signal is outside the 31 30 to +60 db range set in decision step 448 or the iterations time out in step 455 because count signal M>M*. As a result of the intermodulation reduction loop operation, the intermodulation distortion is reduced by readjusting the parameters of amplitude and phase adjuster 122 until an acceptable level of intermodulation distortion is obtained.
The invention has been described with reference to illustrative embodiments thereof. It is apparent, however, to one skilled in the art that various modifications and changes may be made without departing from the spirit and scope of the invention.
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A linear amplifier includes a feed forward circuit which is operative to eliminate distortion of the amplified signal by utilizing a second circuit path parallel to the amplification path to generate a distortion cancellation signal and combine it with the output of the amplification path to cancel the distortion. The gain and phase of the feed forward circuit is automatically adjusted by discrete steps through the operation of a stored program controller. The initial adjustment step is set at some minimum discrete value and its effect on the cancellation level of the feed forward circuit is evaluated. If the cancellation level does not change by a specified amount the adjustment step is increased by a discrete amount. Adjustment of the cancellation level is continued by discrete steps under control of the stored program control until a desired cancellation level is achieved. The number of step adjustments permitted is preset at some value. If the allotted number of step adjustments fail to achieve the desired response, the stored program control checks for the existence of possible fault conditions in the feed forward circuit.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. patent application Ser. No. 12/264,509, filed Nov. 4, 2008, which application is a Continuation of U.S. patent application Ser. No. 10/712,600, filed Nov. 13, 2003, which application is a Continuation-in-Part of U.S. patent application Ser. No. 10/242,976, filed Sep. 13, 2002, which applications are incorporated by reference herein in their entirety.
BACKGROUND OF THE INVENTION
[0002] Medical devices for injecting fluids into a patient are well known in the art. One such type of device is generally referred to as implanted ports, which can be implanted subcutaneously in a patient. Various types of ports can be used to provide access to the peritoneal cavity, as well as the vascular, arterial, and epidural systems. The ports typically include a catheter for access to a large vein and a port body having a septum, which is generally formed from silicone.
[0003] The port is implanted within a cavity formed in the patient, such as in the chest area, and sutured to underlying tissue. From time to time, it is desirable to refill the port via the septum and/or provide an external source of fluid, e.g., IV access. One type of device used to refill an implanted port is generally known as a Huber needle. Known Huber needles generally include a needle extending from a base structure. With sufficient expertise and experience an operator, such as a nurse, can insert the needle into the port via the septum, which is sliced (not cored) by the needle for self-sealing. The Huber needle can then be taped to the patient and fluid delivered to the patient intravenously as desired via a coupled to the Huber needle device.
[0004] However, conventional Huber device can be relatively difficult to remove from the patient. An operator may need to apply a significant amount of force to initiate removal of the device. If the needle suddenly releases, the operator may be accidentally injured by the needle as it is uncontrollably freed from the patient. In addition, even after safe removal, known Huber needle devices can present a hazard due to the outwardly extending needle.
[0005] It would, therefore, be desirable to overcome the aforesaid and other disadvantages.
SUMMARY OF THE INVENTION
[0006] The present invention provides a medical device, such as a Huber needle, having a needle and a structure that enhances user safety during removal of the needle from a patient. The inventive structure reduces the likelihood that medical personnel will suffer injury from the needle as it is forcibly removed from the patient. While the invention is primarily shown and described in conjunction with a Huber-type needle, it is understood that the invention is applicable to devices in general in which it is desirable to reduce the possibility of injury from a needle.
[0007] In one aspect of the invention, a medical device includes a central structural member from which a needle extends. At least one wing portion extends from the central structural member for facilitating removal of the needle from the patient in a controlled manner. A base member for contacting the patient's skin is coupled to the central structural member. First and second members are pivotably secured to the base member so as to provide a structure that can be transitioned from a use position in which the needle extends from the device for insertion into the patient and a non-use position in which the needle is captured by the first member as the needle is extracted from the patient.
[0008] With this arrangement, an operator leverages pressure applied to the wing portion(s) with a finger(s) and counter pressure on the first member so as to enable a controlled removal of the needle from the patient. In addition, the collapsible/expandable structure captures the needle in the first member as it is removed from the patient to enhance operator safety.
[0009] In another aspect of the invention, a medical device has a use position and a non-use position with a housing having first and second portions each having respective first and second ends. The second portion has a first position in the use position and a second position in the non-use position. A longitudinal member has first and second ends and extends from the housing in the use position. In the non-use position, the longitudinal member is captured by the first housing portion. A needle extends from the device in the use position and envelops the device the non-use position. The device can include one or more locking mechanisms to secure the device in the non-use position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0011] FIGS. 1A and 1B are perspective schematic depictions of a medical device having enhanced safety in accordance with the present invention in the non-use position;
[0012] FIG. 2A is a perspective schematic depiction of the medical device of FIG. 1 in the non-use position;
[0013] FIG. 2B is a perspective schematic depiction of the medical device of FIG. 2A in a use position;
[0014] FIG. 2C is a bottom perspective view of the device of FIG. 2B ;
[0015] FIG. 3A is a perspective schematic depiction of a medical device having enhanced safety in accordance with the present invention in a non-use position;
[0016] FIG. 3B is a perspective schematic depiction of the medical device of FIG. 3A in the use position;
[0017] FIG. 4A is a perspective schematic depiction of an exemplary medical device having enhanced safety in accordance with the present invention shown in a non-use position;
[0018] FIG. 4B is a top view of the device of FIG. 4A ;
[0019] FIG. 4C is a sectional view of the device of FIG. 4B ;
[0020] FIG. 5A is a top view of the exemplary medical device of FIG. 4A shown in a use position; and
[0021] FIG. 5B is a sectional view of the device of FIG. 5A along line 5 B.
[0022] FIG. 6 is a perspective schematic representation of an exemplary medical device shown in a use position in accordance with the present invention;
[0023] FIG. 7A is a top view of the medical device of FIG. 6 ;
[0024] FIG. 7B is a side view of the medical device of FIG. 6 ;
[0025] FIG. 7C is a bottom view of the medical device of FIG. 6 ;
[0026] FIG. 7D is a cross-sectional view along line 7 D of the medical device of FIG. 7B ;
[0027] FIG. 8A is a top view of the medical device of FIG. 6 in a non-use position;
[0028] FIG. 8B is a side view of the medical device of FIG. 6 in a non-use position; and
[0029] FIG. 8C is a front view of the medical device of FIG. 6 is a non-use position.
DETAILED DESCRIPTION OF THE INVENTION
[0030] FIGS. 1A-1B show a medical device 100 including a needle 102 and a structure for enhanced operator safety in accordance with the present invention. In general, the device structure facilitates removal of the needle from a patient and captures the needle as it is retracted from the patient's body. During use, the device is relatively flat or collapsed and the needle extends outwardly for insertion into an implanted port device, for example. After use, the device is transitioned to the non-use position in which the needle is captured within the device. As described below, the device can include various features to prevent a transition to the use position from the non-use position to preclude re-use of the device.
[0031] The device 100 includes opposed first and second wing portions 104 a,b extending from a central structural member 106 . As described below, the wing portions 104 provide surfaces on which an operator can apply pressure to insert the device. This arrangement leverages the force applied to the device so as to provide smooth, and safe, insertion and extraction of the needle from the patient.
[0032] FIGS. 2A-2C show further details of an exemplary medical device 100 ′ having a structure providing enhanced safety features in accordance with the present invention. In general, the device of FIGS. 1A and 1B is similar to the device of FIGS. 2A-2C in which like reference designations indicate like elements. The device 100 includes a series of interconnected members that move with respect to the central structural member 106 for safely transitioning the device from use position to the non-use position. The various members shown in FIGS. 2A and 2B are marked with a particular shape as shown to designate the corresponding parts on each of these figures.
[0033] A first member 110 is pivotably coupled to a skin-contacting base member 108 at a pivot 112 . In an exemplary embodiment, the first member 110 includes an arcuate portion 110 a for accommodating the stacked members in the use position, as best shown in FIG. 2B . A second member 114 , at respective pivots 116 , 118 , extends between the base member 108 and the first member 110 . In one embodiment, the second member 114 includes first and second sub portions 114 a,b joined at a pivot point 120 to enable the second member first and second sub portions 114 a,b to fold under the first member 110 . It is understood that these members have mirror images on each side of the central structural member 106 .
[0034] The device further includes a raised portion 122 that can form a part of the first member 110 . As shown in FIGS. 2A and 2B , the raised portion 122 can include a depression 124 that can be pressured by an operator's thumb, for example, to insert the device into the patient. As used herein, the use position refers to the needle outwardly extending from the device for insertion into a patient. In the use position, the device is “flat” or collapsed.
[0035] As shown in FIGS. 2B and 2C , (and 4 C and 5 B) for example, the central structural member 106 can include a slotted channel 126 from which the needle extends perpendicularly, for example. The needle 102 can have an L-shape to facilitate coupling of the needle with a tube (not shown) disposed within the channel 126 . The needle can be secured within the channel 126 in a conventional manner, such as by adhesive.
[0036] The device can include various features to improve the operation and safety of the device. For example, the device can include one or more latches to further enhance operator safety.
[0037] As shown in FIGS. 3A-3B , the device can include a first latching mechanism 150 located at an end of the first member 110 . In one particular embodiment, the first latching mechanism includes a tab 152 to facilitate detachment of a latch member 150 a from a receiving aperture or cutout 150 b in the central structural member 106 . The latching mechanism 150 can be released to raise the first member 110 by lifting the tab 152 prior to removal of the device from the patient.
[0038] A second latch 180 shown in FIGS. 3A (and 4 C) for example, can be located at a tip of the first member 110 so that the needle is retained within the first member. In an exemplary embodiment, the needle 102 is captured by an arcuate cavity 182 formed in the first member 110 . Once the device transitions to the non-use position, the second latch 180 prevents the device from transitioning to the use position by retaining the needle within the cavity.
[0039] In another embodiment (not shown), the device can include mechanisms to provide unidirectional movement to the non-use position. In one embodiment, the first member includes a ratchet-type device allowing only movement of the first member 110 away from the base member 108 .
[0040] Referring again to FIGS. 2A-3B , the structure of the device 100 leverages the force applied to the wing portions 104 and the first member 110 to ease extraction of the needle from the patient. In one embodiment, while the device is flush with the patient's skin, the operator moves the first member 110 to an upright position with respect to the central structural member 106 . The operator then applies first and second fingers underneath the wing portions 104 and a thumb, for example, on or near the tab 152 of the first member 110 . By applying force on top of the upright first member 110 , the implanted port is stabilized in position. The operator can then apply force to lift the wing portions 104 up while applying a counter-force on the first member 110 to leverage the force applied on the wing portions.
[0041] The applied pressure forces the central structural member 106 and wings 104 up and away from the base member 108 and the needle 102 retracts into the cavity 182 in first member 110 . With this arrangement, it is relatively easy for the operator to apply steady pressure to the device for a smooth extraction of the needle from the patient. That is, the needle is not suddenly freed from the patient in a relatively out of control manner. It is understood that the tab 152 can be shaped to facilitate movement of the first member 110 to an upright position and to accommodate force applied to the tab 152 by the operator's thumb.
[0042] FIGS. 4A-5B show further details of a Huber needle-type device, such as the device 100 of FIGS. 1A and 1B , having enhanced safety features in accordance with the present invention. FIGS. 4A-4C show a device in the non-use position from a perspective, top, and sectional view, respectively. FIG. 5A is a top view of a device in the use position in accordance with the present invention and FIG. 5B is a sectional view taken along line 5 B of FIG. 5A .
[0043] In one embodiment, the devices can be delivered in the use position. As described above, the devices can include various features to prevent a transition from the use position to the non-use position.
[0044] In a further aspect of the invention shown in FIG. 6 , a medical device 200 , which is shown in a user position, includes a longitudinal member 202 that slides into a housing 204 . In an exemplary embodiment, the device 200 locks in a non-use position after removal of a needle 206 from a patient. In general, when the device 200 is in the use position, a user can apply finger pressure to first and second wing portions 208 a,b and thumb pressure to an end 202 a of the longitudinal member to force retraction of the needle 206 from the patient's body. When the longitudinal member 202 is captured by the housing 204 , the needle 206 no longer protrudes from the device 200 to enhance operator safety.
[0045] FIGS. 7A-8C show further details of the device 200 shown in FIG. 6 . FIGS. 7A-7D show the device 200 in a first or use position and FIGS. 8A-8C show the device 200 in a second or non-use position. A user or operator transitions the device 200 from the use position to the non-use position as described in detail below.
[0046] As shown in FIGS. 7A-7D , in the use position the needle 206 protrudes from the device 200 for insertion into a patient. The device 200 is relatively flat in the use position so that a bottom surface 210 can rest on a patient while the needle 206 is disposed beneath the skin. The extended longitudinal member 202 includes a channel 212 , which can be centered about a longitudinal axis 214 of the device. The needle 206 extends through the channel, which allows axial movement of the longitudinal member. The longitudinal member 202 further includes a first and optional second locking mechanism 216 a, 216 b for securing the longitudinal member 202 in the non-use position, as described more fully below.
[0047] In an exemplary embodiment, the housing 204 include first and second portions 204 a, 204 b that are secured to each other. In one embodiment, one end of the second housing portion 204 b is coupled to one end of the longitudinal member 202 and the other end of the second housing portion is coupled to an end of the first housing portion 204 a. Optional first and second wing portions 208 a, 208 b extend from the housing first portion 204 a. The wing portions 208 can be arcuate as shown to receive, for example, the application of force by the index and middle fingers of a user.
[0048] A needle retaining member 218 is disposed on the housing 204 for securing the needle 206 , which extends through the channel 212 , in the longitudinal member 202 . The arrangement of the channel 212 and the needle retaining member 218 secures the needle in position while not interfering with movement of the longitudinal member 202 during transition of the device from the use position to the non-use position.
[0049] In one embodiment, the housing 204 further includes first and second locking members 220 a, 220 b that mechanically communicate with the first and second locking members 216 a, 216 b of the longitudinal member 202 . In general, upon complete insertion of the longitudinal member 202 into the housing 204 , the housing locking members 220 align and interlock with the longitudinal member locking members 216 . In the non-use position, the longitudinal member 202 cannot be removed from the housing 204 to prevent re-use of the device and promote user safety.
[0050] FIGS. 8A-8C show the medical device 200 in the non-use position with the longitudinal member 202 fully inserted into housing 204 and the locking members 216 , 220 engaged. The second housing portion 204 b includes a first piece 222 a, and a second piece 222 b that can pivot with respect to each other. In the non-use position, the first and second pieces 222 form an angle of about ninety degrees in one particular embodiment. The angled first and second pieces 222 extend outwardly from the first housing portion 204 a so as to envelope the needle 206 . That is, in the non-use position, the needle 206 does not protrude from the device 200 . A slot 224 ( FIG. 7C ) in the second housing portion 204 a enables the first and second pieces 222 to pivot unencumbered by the needle 206 .
[0051] In one particular embodiment, the non-pivoting end of the first piece 222 a is coupled to the end 202 a of the longitudinal member. As force is applied to the longitudinal member 202 to force it into the housing 204 , movement of the longitudinal member 202 pivots the first piece 222 a with respect to the second piece 222 b. The non-pivoting end of the second piece 222 b is coupled to an end of the first housing portion 204 a.
[0052] In an exemplary embodiment, the second housing portion 204 b includes a series of ribs to create friction as the device 200 transitions to the non-use position during extraction of the needle 206 from the patient. As force is applied to the longitudinal member 202 , the pivoting first and second pieces 222 push against the patient to withdraw the needle 206 .
[0053] It is understood that the device dimensions can vary to meet the needs of a particular application. In one embodiment, the device has a length of about 2.3 inches and a height of about 1.5 inch in the non-use position. The device can have a width measure from ends of the wing portions of about 2.1 inches.
[0054] The inventive medical device shown and described herein can be fabricated from a variety of suitable materials well known to one of ordinary skill in the art. Exemplary materials include plastic, such as PVC, polyethylene, and the like.
[0055] One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety.
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A medical device, such as a Huber-type device, includes a structure that enhances operator safety by reducing the likelihood that a needle will accidentally injure an operator. In one embodiment, the device includes a collapsible structure that can move from a use position to a non-use position. The device includes first and second wing portions and a channel for covering the needle as it is extracted from the patient. The structure enables the operator to leverage applied pressure for a smooth removal of the needle into the device for safe disposal.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No. 12/018,910 filed Jan. 24, 2008 which claims benefit of U.S. Provisional Appln. No. 60/886,675, which was filed Jan. 26, 2007.
FIELD
[0002] This application is directed toward improved methods of synthesizing cationic siloxane prepolymers as well as a specific cationic siloxane prepolymer having improved compatibility with monofunctional siloxanyl methacrylate monomers and medical devices containing the cationic siloxane prepolymer.
BACKGROUND OF THE INVENTION
[0003] US patent application publication number 2007/0142584 filed Jan. 27, 2006, the contents of which are incorporated by reference herein, discloses certain cationic siloxane prepolymers that are able to form water extractable medical devices as well as methods of making the monomers. An example of a monomer made according to the prior synthetic approach is provided in Formula (I) below:
[0000]
[0000] wherein n is an integer from 1 to about 300.
[0004] The method taught in US patent application publication number 2007/0142584 used to synthesize a methacrylate capped cationic siloxane (bromide counter ion) is shown below:
[0000]
[0005] This reaction scheme requires the use of a large excess of the polymerization inhibitor 3,5-Di-tert-4butylhydroxytoluene (BHT) as well as a large excess of the reactant 2-(dimethylamino)ethyl methacrylate (DMAEMA). Another inhibitor which could be used is 4-methoxyphenol (MEHQ). Even though there is a large excess of DMAEMA, this reaction occurs at a very slow rate (100 hours at 60° C.) before product conversion nears 100%. In addition, the boiling point of DMAEMA is 182° C. Due to the cationic nature of the final product, the only way to remove the unreacted DMAEMA is with a combination of high vacuum and heat (stripping). Washing the material results in the emulsification and fractionation of the product. Also, since the product has methacrylate functionality, the stripping of the DMAEMA is problematic and often results in premature polymerization of the reaction product. This is especially the case as the reaction is scaled up. Therefore an improved method of synthesizing cationic siloxane prepolymers would be desirable
[0006] In addition, although monomers such as those claimed in US patent application publication number 2007/0142584 provide medical devices that are entirely suitable in some circumstances, it was determined that medical devices prepared from a monomer mix containing a higher amount of monofunctional siloxane methacrylate would be highly desirable. We have discovered that an iodo salt of a cationic siloxane prepolymer having the structural formula (II) shown below:
[0000]
[0000] allows a greater amount of monofunctional siloxanyl methacrylate to be incorporated in the monomer mix than the bromo salt of a cationic siloxane prepolymer as shown in Formula (III)
[0000]
[0000] wherein n equals 39.
SUMMARY OF THE INVENTION
[0007] Provided herein are methods of making a cationic siloxane prepolymer wherein the reaction product is more easily isolated than cationic siloxane prepolymers prepared according to a previous method. The method comprises, in one embodiment, reacting bis-bromobutyl polydimethylsiloxane with 2-(methylamino)ethanol in polar solvent such as dioxane to provide a first reaction product. The first reaction product is then reacted with methacryloyl chloride or methacrylic anhydride in the presence of triethylamine in polar solvent such as chloroform to provide a second reaction product. The second reaction product is then reacted with iodomethane in tetrahydrofuran to provide the third reaction product as a cationic functionalized siloxane prepolymer.
[0008] Also provided is an improved cationic siloxane prepolymer that provides a lens material having improved properties as compared to other cationic siloxane polymers. The improved cationic siloxane prepolymer is a monomer having the following formula (IV):
[0000]
[0000] wherein n is from 0 to 200.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] None
DETAILED DESCRIPTION
[0010] Provided herein is an improved method of making functionalized cationic siloxane prepolymers. In one embodiment, the method comprises reacting a bis-halide polysiloxane such as bis-bromobutyl polydimethylsiloxane with an alkyl functionalized hydroxy secondary amine such 2-(methylamino)ethanol to provide a first reaction product. Other alkyl functionalized hydroxy secondary amines would include 2-(ethylamino)ethanol, 2-(propylamino)ethanol, 2-(butylamino)ethanol.
[0011] The reaction is conducted in a polar solvent. Polar solvents are selected because they are able to dissolve the reactants and increase the reaction rate. Examples of polar solvents would include ethyl acetate, dioxane, THF, DMF, chloroform, etc.
[0012] The first reaction product is then reacted with a methacrylating agent to provide a second reaction product having vinyl polymerizable endgroups on the polysiloxane. Examples of methacrylating agents would include methacryloyl chloride, methacrylic anhydride, 2-isocyanatoethyl methacrylate, itaconic acid and itaconic anhydride.
[0013] Because HCl is produced during this stage of the reaction, which may result in deterioration of the polysiloxane, an acid scavenger such as triethylamine, triethanolamine, or 4-dimethylaminopyridine is used to reduce the amount of HCl formed during the synthesis. As utilized herein the expression “acid scavenger” refers to a material that reacts with any acid that is otherwise formed during the synthesis to prevent the degradation of the reaction product.
[0014] To quaternize the amine groups in the polysiloxane of the second reaction product an alkyl halide such as iodomethane is used as a quaternizing agent to provide the final third reaction product. The final product is isolated by removal of the solvent and any residual alkyl halide from the reaction mixture.
[0015] A schematic representation of the method is provided in the reaction schematic below:
[0000]
[0016] This new synthetic route divides the synthesis into three steps and differs dramatically from the previous procedure in that the quat functionality is formed at the last step of the reaction. This change in synthetic route allows for easy removal of unreacted starting materials and significantly reduces the occurrence of premature polymerization. Use of lower levels of polymerization inhibitor in the synthesis of the cationic siloxane prepolymer is also able to be achieved.
[0017] Following the given synthetic scheme, a known amount of bis-bromobutyl polydimethylsiloxane with known molecular weight was refluxed in dioxane with 2-(methylamino)ethanol for 72 hours at 75° C. to afford reaction product (1) after isolation. The structure of (1) was verified by NMR analysis. Product (1), with chloroform as a solvent, was then allowed to react with methacryloyl chloride in the presence of triethylamine at ambient temperature to afford reaction product (2) after isolation. The structure of product (2) was also verified by NMR analysis. The final step of the synthesis was the quaternization of (2) with iodomethane, using THF as a solvent, to afford reaction product (3) after 15 hours at 45° C. The structure of the final product, (3), was verified by NMR, SEC, and Mass Spectrometry analyses.
[0018] The method is particularly useful for synthesizing the following prepolymer which has desirable properties for forming a medical device.
[0000]
[0000] wherein n is from 0 to 200.
[0019] A preferred monomer is shown below wherein n equals 39.
[0000]
[0020] It was surprisingly discovered that use of the iodo salt of the cationic polysiloxane prepolymer, as compared to the bromo salt form, resulted in a monomer mix having improved compatibility with the other prepolymers. Improved compatibility was demonstrated by a visual comparison made between the two formulations. Greater than 3% of a monofunctional polysiloxane material caused cloudiness in the formulation made with the bromo salt of a cationic siloxane prepolymer, while up to 4.5% monofunctional polysiloxane material was added to a formulation made with the iodo salt of a cationic siloxane prepolymer without cloudiness resulting. This improved compatibility results in a monomer mix that allows increased concentrations of mono functional comonomers resulting in a polymerized product having improved physical properties.
[0021] In a further aspect, the invention includes articles formed of device forming monomer mixes comprising the prepolymers of formula (IV). According to preferred embodiments, the article is the polymerization product of a mixture comprising the aforementioned cationic siloxane prepolymer of formula (II) and at least a second monomer. Preferred articles are optically clear and useful as a contact lens.
[0022] Useful articles made with these materials may require hydrophobic, possibly silicon containing monomers. Preferred compositions have both hydrophilic and hydrophobic monomers. The invention is applicable to a wide variety of polymeric materials, either rigid or soft. Especially preferred polymeric materials are lenses including contact lenses, phakic and aphakic intraocular lenses and corneal implants although all polymeric materials including biomaterials are contemplated as being within the scope of this invention. Especially preferred are silicon containing hydrogels.
[0023] The present invention also provides medical devices such as heart valves and films, surgical devices, vessel substitutes, intrauterine devices, membranes, diaphragms, surgical implants, blood vessels, artificial ureters, artificial breast tissue and membranes intended to come into contact with body fluid outside of the body, e.g., membranes for kidney dialysis and heart/lung machines and the like, catheters, mouth guards, denture liners, ophthalmic devices, and especially contact lenses.
[0024] Silicon containing hydrogels are prepared by polymerizing a mixture containing at least one silicon-containing monomer and at least one hydrophilic monomer. The silicon-containing monomer may function as a crosslinking agent (a crosslinker being defined as a monomer having multiple polymerizable functionalities) or a separate crosslinker may be employed.
[0025] An early example of a silicon-containing contact lens material is disclosed in U.S. Pat. No. 4,153,641 (Deichert et al assigned to Bausch & Lomb Incorporated). Lenses are made from poly(organosiloxane) monomers which are α, ω terminally bonded through a divalent hydrocarbon group to a polymerized activated unsaturated group. Various hydrophobic silicon-containing prepolymers such as 1,3-bis(methacryloxyalkyl)-polysiloxanes were copolymerized with known hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA).
[0026] U.S. Pat. No. 5,358,995 (Lai et al) describes a silicon containing hydrogel which is comprised of an acrylic ester-capped polysiloxane prepolymer, polymerized with a bulky polysiloxanylalkyl(meth)acrylate monomer, and at least one hydrophilic monomer. Lai et al is assigned to Bausch & Lomb Incorporated and the entire disclosure is incorporated herein by reference. The acrylic ester-capped polysiloxane prepolymer, commonly known as M 2 D x consists of two acrylic ester end groups and “x” number of repeating dimethylsiloxane units. The preferred bulky polysiloxanylalkyl(meth)acrylate monomers are TRIS-type (methacryloxypropyl tris(trimethylsiloxy)silane) with the hydrophilic monomers being either acrylic- or vinyl-containing.
[0027] Other examples of silicon-containing monomer mixtures which may be used with this invention include the following: vinyl carbonate and vinyl carbamate monomer mixtures as disclosed in U.S. Pat. Nos. 5,070,215 and 5,610,252 (Bambury et al); fluorosilicon monomer mixtures as disclosed in U.S. Pat. Nos. 5,321,108; 5,387,662 and 5,539,016 (Kunzler et al); fumarate monomer mixtures as disclosed in U.S. Pat. Nos. 5,374,662; 5,420,324 and 5,496,871 (Lai et al) and urethane monomer mixtures as disclosed in U.S. Pat. Nos. 5,451,651; 5,648,515; 5,639,908 and 5,594,085 (Lai et al), all of which are commonly assigned to assignee herein Bausch & Lomb Incorporated, and the entire disclosures of which are incorporated herein by reference.
[0028] Examples of non-silicon hydrophobic materials include alkyl acrylates and methacrylates.
[0029] The cationic siloxane prepolymer may be copolymerized with a wide variety of hydrophilic monomers to produce silicon hydrogel lenses. Suitable hydrophilic monomers include: unsaturated carboxylic acids, such as methacrylic and acrylic acids; acrylic substituted alcohols, such as 2-hydroxyethylmethacrylate and 2-hydroxyethylacrylate; vinyl lactams, such as N-vinyl pyrrolidone (NVP) and 1-vinylazonam-2-one; and acrylamides, such as methacrylamide and N,N-dimethylacrylamide (DMA).
[0030] Still further examples are the hydrophilic vinyl carbonate or vinyl carbamate monomers disclosed in U.S. Pat. No. 5,070,215, and the hydrophilic oxazolone monomers disclosed in U.S. Pat. No. 4,910,277. Other suitable hydrophilic monomers will be apparent to one skilled in the art.
[0031] Hydrophobic cross-linkers would include methacrylates such as ethylene glycol dimethacrylate (EGDMA) and allyl methacrylate (AMA). In contrast to traditional silicon hydrogel monomer mixtures, the monomer mixtures containing the quaternized siloxane prepolymer of the invention herein are relatively water soluble. This feature provides advantages over traditional silicon hydrogel monomer mixtures in that there is less risk of incompatibility phase separation resulting in hazy lenses and the polymerized materials are extractable with water. However, when desired, traditional organic extraction methods may also be used. In addition, the extracted lenses demonstrate a good combination of oxygen permeability (Dk) and low modulus, properties known to be important to obtaining desirable contact lenses. Moreover, lenses prepared with the quaternized siloxane prepolymers of the invention herein are wettable even without surface treatment, provide dry mold release, do not require solvents in the monomer mix (although solvents such as glycerol may be used) the extracted polymerized material is not cytotoxic and the surface is lubricious to the touch. In cases where the polymerized monomer mix containing the quaternized siloxane prepolymers of the invention herein do not demonstrate a desirable tear strength, toughening agents such as TBE (4-t-butyl-2-hydroxycyclohexyl methacrylate) may be added to the monomer mix. Other strengthening agents are well known to those of ordinary skill in the art and may also be used when needed.
[0032] Although an advantage of the cationic siloxane prepolymers disclosed herein is that they are relatively water soluble and also soluble in their comonomers, an organic diluent may be included in the initial monomeric mixture. As used herein, the term “organic diluent” encompasses organic compounds which minimize incompatibility of the components in the initial monomeric mixture and are substantially nonreactive with the components in the initial mixture. Additionally, the organic diluent serves to minimize phase separation of polymerized products produced by polymerization of the monomeric mixture. Also, the organic diluent will generally be relatively non-inflammable.
[0033] Contemplated organic diluents include tent-butanol (TBA); diols, such as ethylene glycol and propylene glycol; and polyols, such as glycerol. Preferably, the organic diluent is sufficiently soluble in the extraction solvent to facilitate its removal from a cured article during the extraction step.
[0034] Other suitable organic diluents would be apparent to a person of ordinary skill in the art.
[0035] The organic diluent is included in an amount effective to provide the desired effect. Generally, the diluent is included at 5 to 60% by weight of the monomeric mixture, with 10 to 50% by weight being especially preferred.
[0036] According to the present process, the monomeric mixture, comprising at least one hydrophilic monomer, at least one cationic siloxane prepolymer and optionally the organic diluent, is shaped and cured by conventional methods such as static casting or spincasting.
[0037] Lens formation can be by free radical polymerization such as azobisisobutyronitrile (AIBN) and peroxide catalysts using initiators and under conditions such as those set forth in U.S. Pat. No. 3,808,179, incorporated herein by reference. Photo initiation of polymerization of the monomer mixture as is well known in the art may also be used in the process of forming an article as disclosed herein. Colorants and the like may be added prior to monomer polymerization.
[0038] Subsequently, a sufficient amount of unreacted monomer and, when present, organic diluent is removed from the cured article to improve the biocompatibility of the article. Release of non-polymerized monomers into the eye upon installation of a lens can cause irritation and other problems. Unlike other monomer mixtures that must be extracted with flammable solvents such as isopropyl alcohol, because of the properties of the novel quaternized siloxane prepolymers disclosed herein, non-flammable solvents including water may be used for the extraction process.
[0039] Once the biomaterials formed from the polymerized monomer mix containing the cationic siloxane prepolymers monomers disclosed herein are formed they are then extracted to prepare them for packaging and eventual use. Extraction is accomplished by exposing the polymerized materials to various solvents such as water, tert-butanol, etc. for varying periods of time. For example, one extraction process is to immerse the polymerized materials in water for about three minutes, remove the water and then immerse the polymerized materials in another aliquot of water for about three minutes, remove that aliquot of water and then autoclave the polymerized material in water or buffer solution.
[0040] Following extraction of unreacted monomers and any organic diluent, the shaped article, for example an RGP lens, is optionally machined by various processes known in the art. The machining step includes lathe cutting a lens surface, lathe cutting a lens edge, buffing a lens edge or polishing a lens edge or surface. The present process is particularly advantageous for processes wherein a lens surface is lathe cut, since machining of a lens surface is especially difficult when the surface is tacky or rubbery.
[0041] Generally, such machining processes are performed before the article is released from a mold part. After the machining operation, the lens can be released from the mold part and hydrated. Alternately, the article can be machined after removal from the mold part and then hydrated.
EXAMPLES
[0042] All solvents and reagents were obtained from Sigma-Aldrich, Milwaukee, Wis., and used as received with the exception of aminopropyl terminated poly(dimethylsiloxane), 900-1000 and 3000 g/mol, obtained from Gelest, Inc., Morrisville, Pa., and methacryloxypropyltris(trimethylsiloxy)silane, obtained from Silar Laboratories, Scotia, N.Y., which were both used without further purification. The monomers 2-(hydroxyethyl)methacrylate and 1-vinyl-2-pyrrolidone were purified using standard techniques.
Analytical Measurements
[0043] NMR: 1 H-Nuclear Magnetic Resonance (NMR) characterization is carried out using a 400 MHz Varian spectrometer using standard techniques in the art. Samples are dissolved in chloroform-d (99.8 atom % D), unless otherwise noted. Chemical shifts are determined by assigning the residual chloroform peak at 7.25 ppm. Peak areas and proton ratios are determined by integration of baseline separated peaks. Splitting patterns (s=singlet, d=doublet, t=triplet, q=quartet, m=multiplet, br=broad) and coupling constants (J/Hz) are reported when present and clearly distinguishable.
[0044] SEC: Size Exclusion Chromatography (SEC) analyses are carried out by injection of 100 μL of sample dissolved in tetrahydrofuran (THF) (5-20 mg/mL) onto a Polymer Labs PL Gel Mixed Bed E (×2) column at 35° C. using a Waters 515 HPLC pump and HPLC grade THF mobile phase flow rate of 1.0 mL/min, and detected by a Waters 410 Differential Refractometer at 35° C. Values of M n , M w , and polydispersity (PD) is determined by comparison to Polymer Lab Polystyrene narrow standards.
[0045] EST-TOF MS: The electrospray (ESI) time of flight (TOF) MS analysis was performed on an Applied Biosystems Mariner instrument. The instrument operated in positive ion mode. The instrument is mass calibrated with a standard solution containing lysine, angiotensinogen, bradykinin (fragment 1-5) and des-Pro bradykinin. This mixture provides a seven-point calibration from 147 to 921 m/z. The applied voltage parameters are optimized from signal obtained from the same standard solution.
[0046] Stock solutions of the polymer samples are prepared as 1 mg/mL in tetrahydrofuran (THF). From these stock solutions, samples are prepared for ESI-TOF MS analysis as 30 μM solutions in isopropanol (IPA) with the addition of 2% by volume saturated NaCl in WA. Samples are directly infused into the ESI-TOF MS instrument at a rate of 35 μL/min.
[0047] Mechanical properties and Oxygen Permeability: Modulus and elongation tests are conducted according to ASTM D-1708a, employing an Instron (Model 4502) instrument where the hydrogel film sample is immersed in borate buffered saline; an appropriate size of the film sample is gauge length 22 mm and width 4.75 mm, where the sample further has ends forming a dog bone shape to accommodate gripping of the sample with clamps of the Instron instrument, and a thickness of 200+50 microns.
[0048] Oxygen permeability (also referred to as Dk) is determined by the following procedure. Other methods and/or instruments may be used as long as the oxygen permeability values obtained therefrom are equivalent to the described method. The oxygen permeability of silicone hydrogels is measured by the polarographic method (ANSI Z80.20-1998) using an O2 Permeometer Model 201T instrument (Createch, Albany, Calif. USA) having a probe containing a central, circular gold cathode at its end and a silver anode insulated from the cathode. Measurements are taken only on pre-inspected pinhole-free, flat silicone hydrogel film samples of three different center thicknesses ranging from 150 to 600 microns. Center thickness measurements of the film samples may be measured using a Rehder ET-1 electronic thickness gauge. Generally, the film samples have the shape of a circular disk. Measurements are taken with the film sample and probe immersed in a bath containing circulating phosphate buffered saline (PBS) equilibrated at 35° C.+/−0.2°. Prior to immersing the probe and film sample in the PBS bath, the film sample is placed and centered on the cathode premoistened with the equilibrated PBS, ensuring no air bubbles or excess PBS exists between the cathode and the film sample, and the film sample is then secured to the probe with a mounting cap, with the cathode portion of the probe contacting only the film sample. For silicone hydrogel films, it is frequently useful to employ a Teflon polymer membrane, e.g., having a circular disk shape, between the probe cathode and the film sample. In such cases, the Teflon membrane is first placed on the pre-moistened cathode, and then the film sample is placed on the Teflon membrane, ensuring no air bubbles or excess PBS exists beneath the Teflon membrane or film sample. Once measurements are collected, only data with correlation coefficient value (R2) of 0.97 or higher should be entered into the calculation of Dk value. At least two Dk measurements per thickness, and meeting R2 value, are obtained. Using known regression analyses, oxygen permeability (Dk) is calculated from the film samples having at least three different thicknesses. Any film samples hydrated with solutions other than PBS are first soaked in purified water and allowed to equilibrate for at least 24 hours, and then soaked in PHB and allowed to equilibrate for at least 12 hours. The instruments are regularly cleaned and regularly calibrated using RGP standards. Upper and lower limits are established by calculating a +/−8.8% of the Repository values established by William J. Benjamin, et al., The Oxygen Permeability of Reference Materials, Optom Vis Sci 7 (12s): 95 (1997), the disclosure of which is incorporated herein in its entirety:
[0000]
Material Name
Repository Values
Lower Limit
Upper Limit
Fluoroperm 30
26.2
24
29
Menicon EX
62.4
56
66
Quantum II
92.9
85
101
Abbreviations
[0000]
MI-MCR-C12
[0000]
NVP 1-Vinyl-2-pyrrolidone
TRIS Methacryloxypropyltris(trimethylsiloxy)silane
HEMA 2-Hydroxyethyl methacrylate
v-64 2,2′-Azobis(2-methylpropionitrile)
PG 1,3-Propanediol
EGDMA Ethylene glycol dimethacrylate
SA 2-[3-(2H-Benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate
IMVT 1,4-bis[4-(2-methacryloxyethyl)phenylamino]anthraquinone
[0058] Liquid monomer solutions containing cationic end-capped poly(dimethylsiloxane) prepolymers from examples below, along with other additives common to ophthalmic materials (diluent, initiator, etc.) are clamped between silanized glass plates at various thicknesses and polymerized using thermal decomposition of the free-radical generating additive by heating 2 h at 100° C. under a nitrogen atmosphere. Each of the formulations affords a transparent, tack-free, insoluble film.
[0059] Films are removed from glass plates and hydrated/extracted in deionized H 2 O for a minimum of 4 hours, transferred to fresh deionized H 2 O and autoclaved 30 min at 121° C. The cooled films are then analyzed for selected properties of interest in ophthalmic materials. Mechanical tests are conducted in borate buffered saline according to ASTM D-1708a, discussed above. The oxygen permeabilities, reported in Dk (or barrer) units, are measured in phosphate buffered saline at 35° C., using acceptable films with three different thicknesses, as discussed above.
[0060] Unless otherwise specifically stated or made clear by its usage, all numbers used in the examples should be considered to be modified by the term “about” and to be weight percent.
EXAMPLE 1
Synthesis of 1,3-bis(4-bromobutyl)tetramethyldisiloxane RD-1862 “Iodo M2D39 Plus”
[0061] This example details the synthetic procedure for the production of the intermediate, 1,3-bis(4-bromobutyl)tetramethyldisiloxane.
I. Preparation of 1,3-bis(4-bromobutyl)tetramethyldisiloxane
[0062]
Materials
[0000]
1,3-bis(4-hydroxybutyl)tetramethyldisiloxane, vacuum stripped at 60° C. and 0.6 mbar for 2 hours
Aliquot® 336 (reg. trademark of Henkel Corporation), as received
Toluene (99.5%), as received
Hydrobromic acid (48%) aqueous HBr), as received
Saturated NaCl
0.5 M Sodium Bicarbonate solution
Magnesium Sulfate (anhydrous), as received
Silica gel 60 (E. Merck 7734-4), as received
Heptane (99%), as received
Methylene chloride (99.5%), as received
Equipment
[0000]
5 L 3-neck round bottom Morton flask
Teflon bladed mechanical stirrer
Condenser
Thermometer
6 L separatory funnel
Vacuum filtration apparatus
House (low) vacuum setup
Vacuum pump, roughing
Chromatography column (3.5 in.×30. in.)
Rotary evaporator
Tolerances
[0000]
Temperatures: ±2° C.
Times: ±1 hour
Volumes: ±10 mL
Weights: ±0.2 g
Preparation
[0000]
A 5 L 3-neck round bottom Morton flask is equipped with a Teflon bladed mechanical stirring system and a condenser.
2. 1,3-bis(4-hydroxybutyl)tetramethyldisiloxane (837.2 g, 3.0 mol) is added to the flask along with 48.6 g (0.12 mol) Aliquat® 336 in toluene (1000 mL) and 2.0 L of 48% HBr (aq).
3. The reaction mixture is heated to 100° C. for 16 hours with vigorous stirring.
4. After cooling, the organic layer is separated in a 6 L separatory funnel.
5. Wash with 1×2 L saturated NaCl, 0.5 M Sodium Bicarbonate solution (3×500 mL).
6. Dry over magnesium sulfate and filter product by vacuum.
7. Heat product to 60° C. and remove solvents with roughing pump (1.3 mbar). Crude yield is expected to be about 1250 g.
8. A silica gel column (2 kg silica gel, column 3.5 inches in diameter and 30 inches long) is prepared by slurry packing with heptane.
9. The yellow silicone liquid is placed on the silica gel chromatography column with heptane (200 g).
10. Elute with 1.5 L 100% heptane, 1 L 100% heptane, 1 L 80% heptane 20% methylene chloride, then 1 L 60% heptane 40% methylene chloride until done.
11. Start collecting after the first 1 L collected as Fraction “0”. The organic fractions 1 (65.6 g), 2, 3 (343 g), 4, 5, 6 (33 g), 7 (31 g), 8 (19.4 g), were recombined and solvents removed by flash vaporization by a Rotary evaporator at reduced pressure to afford 1093.4 g of 1,3-bis(4-bromobutyl)tetramethyldisiloxane as a colorless liquid.
EXAMPLE 2
Synthesis of Poly(dimethylsiloxane) Terminated with Cationic Polymerizable Functionality (RD-1862 “Iodo M2D39 Plus”)
[0098]
[0099] This example details the synthetic procedure for the production of the final product, cationic methacrylate terminated poly(dimethylsiloxane), “Iodo M2D39 Plus”.
Materials
[0000]
Drierite (8 mesh), as received
1,3-bis(4-bromobutyl)tetramethyldisiloxane (96.5%), as received
Octamethylcyclotetrasiloxane (D 4 ) (98%), as received
Trifluoromethanesulfonic acid (98%), as received
Sodium bicarbonate (99.7%), as received
Celite 503, as received
Acetone (99%), as received
Dry ice, as received
1,4-Dioxane (anhydrous, 99.8%), as received
2-(Methylamino)ethanol (98%), as received
Chloroform (anhydrous, 99%), as received
Brine solution
Deionized water
Magnesium sulfate (anhydrous), as received
Triethylamine (99.5%), as received
2,6-Di-tert-butyl-methylphenol (BHT) (99%), as received
Methacryloyl chloride (≧97%), as received
Sodium carbonate (99%), as received
Amberlyst A26 hydroxide form resin, as received
Tetrahydrofuran (anhydrous, 99.9%), as received
Iodomethane (99%), as received
Equipment
[0000]
Flasks: 1000 mL round bottom (×3), 3-neck 1000 mL round bottom, 500 mL pressure flask (round bottom)
Teflon bladed mechanical stirrer
Drying tube
Pressure filter (stainless steel)
Nitrogen gas
PTFE filter (5 μm)
Magnetic stir plate
Magnetic stir bar
Thermometers
Vacuum pump, roughing
Vacuum traps
1 L Heating mantle
Temperature controller with thermocouple
Condenser (water-cooled)
Rubber septa
Rotary evaporator
Separatory funnel (1000 mL)
Vacuum filtration apparatus
Glass microfiber filter paper (retains samples down to 0.7 μm)
House (low) vacuum setup
Heat gun
Addition funnel (100 mL)
Oil bath
Aluminum foil
Refrigerator/freezer
Dry box (<5% relative humidity)
House air (dry, oil free)
Funnels
Spatulas
Tolerances
[0000]
Temperatures: ±2° C.
Times: ±1 hour, unless noted otherwise
Volumes: ±1 mL
Weights: ±1 g
Preparation
Step 1: Ring-Opening Polymerization
[0000]
1. In a 1000 mL round bottom flask equipped with an overhead mechanical stirrer and drying tube (with Drierite), 1,3-bis(4-bromobutyl)tetramethyldisiloxane (61.3 g) and octamethylcyclotetrasiloxane (438.7 g) are added.
2. Trifluoromethanesulfonic acid (1.25 g, 0.25 w/w %) is added and stirred 24 hours at room temperature.
3. To the reaction is added sodium bicarbonate (7 g) and the mixture is allowed to stir at a moderate rate for an additional 24 hours at room temperature.
4. The mixture is then filtered with slight positive nitrogen pressure through a pressure filter system equipped with 5 μm PTFE filter and a Celite pad into a 1000 mL round bottom flask.
5. The mixture is stirred magnetically and stripped for at least 4 hours at 80° C. and <1.3 mbar using a vacuum pump and acetone/dry ice trap, or until collection of residual octamethylcyclotetrasiloxane is essentially complete (no further collection of liquid) to afford the product as a transparent, colorless, viscous liquid (426 g, 85% yield).
Product: 1,3-bis(4-bromobutyl)poly(dimethylsiloxane) as a transparent colorless liquid
M n =1500-3000, and PD=1.5-2.5 by gel permeation chromatography (GPC)
Step 2: Reaction with 2-(methylamino)ethanol
1. The colorless liquid product from step 1.5 above (200 g) was then dissolved in 1,4-dioxane (500 mL, 2.5 mL/g dioxane to silicone) in a 3-neck 1000 mL round bottom flask. The flask was equipped a mechanical stirring system, a 1 L heating mantle, a water-cooled condenser, and a thermocouple to monitor the reaction temperature. 2. 2-(methylamino)ethanol (30 mL, 6 mol eq.) was added to the reaction vessel. 3. The flask was sealed with rubber septum and placed under a nitrogen purge. 4. The reaction was then heated for 72 hours at 100° C. and stirred vigorously. 5. The contents of 3-neck 1000 mL flask were transferred to 1-neck 1000 mL round bottom flask and dioxane was removed via a rotary evaporator. 6. Silicone product was redissolved in chloroform and transferred to 1000 mL separatory funnel. 7. Product washed with 500 mL brine solution (2×), 500 mL 5% sodium bicarbonate solution (3×), followed by another wash with 500 mL brine solution. 8. Silicone product collected from Step 2.7 and dried with magnesium sulfate (enough to absorb all the water in the product). 9. Product vacuum filtered and solvent removed with a rotary evaporator/vacuum pump to afford intermediate product. 10. Product confirmed with NMR spectroscopy.
Step 3: Methacrylation with Methacryloyl Chloride
1. Silicone product from Step 2.9 was redissolved in anhydrous chloroform (3.0 mL/g silicone) and transferred to 1000 mL round bottom flask (dried with heat gun) with magnetic stir bar. 2. Triethylamine (6 mol eq.) was added to the reaction, along with 250 ppm BHT inhibitor. 3. An addition funnel (dried with heat gun) was added to the flask and methacryloyl chloride (4 mol eq.) was added to the funnel along with chloroform to dilute the acid chloride (approx. twice the volume of the acid chloride). The system was then capped with rubber septum and purged with N 2 . 4. The reaction was stirred and the acid chloride was added dropwise. The reaction was allowed to stir 15 hours at ambient temperature. 5. Reaction transferred to 1000 mL separatory funnel and washed with 500 mL brine solution (×2), 500 mL 5% sodium carbonate solution (×2), and again with 500 mL brine solution. 6. An excess of Amberlyst A26 resin was rinsed with chloroform and then stirred into the product from Step 3.5 for one hour. Magnesium sulfate added to dry system. 7. Solids vacuum filtrated out of product and product concentrated via rotary evaporator. 8. Product confirmed via NMR spectroscopy.
Step #4: Quaternization
[0000]
1. Product from Step 3.7 dissolved in THF (2.0 mL/g silicone) and transferred to 500 mL round bottom pressure flask with stir bar.
2. Iodomethane (8 mol eq.) added to reaction.
3. Reaction vessel sealed and allowed to stir in a 45° C. oil bath for 15 hours protected from light (wrapped in Al foil).
4. System placed on a rotary evaporator to remove all solvent and excess iodomethane to afford a yellow, waxy solid product.
5. Product sealed and allowed to harden at approx. −20° C.
6. Product chopped with spatula and residual iodomethane/solvent removed with vacuum pump (product kept at ambient temperature).
7. Product moved to dry box with dry air environment for transferring, sampling, etc. and stored at −20° C. with a drying agent to prevent moisture contamination.
8. Product confirmed by NMR spectroscopy, Mass Spectrometry, Gel Permeation Chromatography, and Gas Chromatography.
[0187] Cationic methacrylate terminated poly(dimethylsiloxane) (RD-1862, “Iodo M2D39 Plus”) as a slightly yellow, waxy-solid product.
EXAMPLE 3
Synthesis of RD-1862 “Iodo M 2 D 29 Plus”
Purpose
[0188] This document details the synthetic procedure for the production of the intermediate, 1,3-bis(4-bromobutyl)tetramethyldisiloxane and the final product, cationic methacrylate terminated poly(dimethylsiloxane), “Iodo M 2 D 39 Plus”.
I. Preparation of 1,3-bis(4-bromobutyl)tetramethyldisiloxane
[0189]
Materials
[0000]
1,3-bis(4-hydroxybutyl)tetramethyldisiloxane, vacuum stripped at 60° C. and 0.6 mbar for 2 hours
Aliquot® 336 (reg. trademark of Henkel Corporation), as received from Aldrich
Toluene (99.5%), as received from Aldrich
Hydrobromic acid (48%) aqueous HBr), as received from Aldrich
Saturated sodium chloride solution
0.5 M Sodium bicarbonate solution
Magnesium sulfate (anhydrous), as received from Fisher Scientific
Silica gel 60 (E. Merck 7734-4), as received
Heptane (99%), as received from Aldrich
Methylene chloride (99.5%), as received from Aldrich
Equipment
[0000]
5 L 3-neck round bottom Morton flask
Teflon bladed mechanical stirrer
Teflon stirrer bearing
Teflon sleeves
Condenser
Thermometer or thermocouple
6 L separatory funnel
Vacuum filtration apparatus
House (low) vacuum setup
Vacuum pump, roughing
Chromatography column (3.5 in.×30. in.)
Rotary evaporator
Tolerances
[0000]
Temperatures: ±2° C.
Times: ±1 hour
Volumes: ±10 mL
Weights: ±0.2 g
Preparation
[0000]
1. A 5 L 3-neck round bottom Morton flask is equipped with a Teflon bladed mechanical stirring system and a condenser.
2. 1,3-bis(4-hydroxybutyl)tetramethyldisiloxane (837.2 g, 3.0 mol) is added to the flask along with 48.6 g (0.12 mol) Aliquat® 336 in toluene (1000 mL) and 2.0 L of 48% HBr (aq).
3. The reaction mixture is heated to 100° C. for 16 hours with vigorous stirring.
4. After cooling, the organic layer is separated in a 6 L separatory funnel.
5. Wash with 1×2 L saturated NaCl, 0.5 M Sodium Bicarbonate solution (3×500 mL).
6. Dry over magnesium sulfate and filter product by vacuum.
7. Heat product to 60° C. and remove solvents with roughing pump (1.3 mbar). Crude yield is expected to be about 1250 g.
8. A silica gel column (2 kg silica gel, column 3.5 inches in diameter and 30 inches long) is prepared by slurry packing with heptane.
9. The yellow silicone liquid is placed on the silica gel chromatography column with heptane (200 g).
10. Elute with 1.5 L 100% heptane, 1 L 100% heptane, 1 L 80% heptane 20% methylene chloride, then 1 L 60% heptane 40% methylene chloride until done.
11. Start collecting after the first 1 L collected as Fraction “0”. The organic fractions 1 (65.6 g), 2, 3 (343 g), 4, 5, 6 (33 g), 7 (31 g), 8 (19.4 g), were recombined and solvents removed by flash vaporization by a Rotary evaporator at reduced pressure to afford 1093.4 g of 1,3-bis(4-bromobutyl)tetramethyldisiloxane as a colorless liquid.
II. Synthesis of Poly(dimethylsiloxane) Terminated with Cationic Polymerizable Functionality
Overview:
[0227]
Materials
[0000]
Drierite (8 mesh), as received from Fisher Scientific
1,3-bis(4-bromobutyl)tetramethyldisiloxane (96.5%), made according to above procedure
Octamethylcyclotetrasiloxane (D 4 ) (98%), as received
Trifluoromethanesulfonic acid (98%), as received from Aldrich
Sodium bicarbonate (99.7%), as received Fisher Scientific
Celite 503, as received from Fisher Scientific
Acetone (99%), as received from Aldrich
Dry ice
1,4-Dioxane (anhydrous, 99.8%), as received from Aldrich
2-(Methylamino)ethanol (98%), as received from Aldrich
Chloroform (anhydrous, 99%), as received from Aldrich
Saturated sodium chloride solution (Brine)
Deionized water
Magnesium sulfate (anhydrous), as received from Fisher Scientific
Triethylamine (99.5%), as received from Aldrich
2,6-Di-tert-butyl-methylphenol (BHT) (99%), as received from Aldrich
Methacrylic anhydride (≧94%), as received from Aldrich
Dimethylamino pyridine (97%), as received from Aldrich
Sodium carbonate (99%), as received from Fisher Scientific
Amberlyst A26 hydroxide form resin, as received from Aldrich
Tetrahydrofuran (anhydrous, 99.9%), as received from Aldrich
Iodomethane (99%), as received from Aldrich
Equipment
[0000]
Flasks: 1000 mL round bottom (1-neck), 1000 mL round bottom (2-neck), 2000 mL round bottom (1-neck), 2000 mL round bottom (3-neck).
Teflon bladed mechanical stirrer
Teflon stir bearing
Teflon sleeves
Teflon stoppers
Drying tube
Pressure filter (stainless steel)
Nitrogen gas
PTFE filter (5 μm)
Magnetic stir plate
Magnetic stir bars
Thermometers
Vacuum pump, roughing
Vacuum traps
2 L Heating mantle
Temperature controller with thermocouple
Condenser (water-cooled)
Rubber septa
Rotary evaporator
Separatory funnel (4000 mL)
Vacuum filtration apparatus
Glass microfiber filter paper (retains samples down to 0.7 μm)
House (low) vacuum setup
Heat gun
Addition funnel (250 mL)
Water bath
Refrigerator/freezer
Dry box (≦5% relative humidity)
House air (dry, oil free)
Funnels
Spatulas
Tolerances
[0000]
Temperatures: ±2° C.
Times: ±1 hour, unless noted otherwise
Volumes: ±1 mL
Weights: ±1 g
Preparation
Step 1: Ring-Opening Polymerization
[0000]
1. In a 2-neck 1000 mL round bottom flask equipped with an overhead mechanical stirrer and drying tube (with Drierite), 1,3-bis(4-bromobutyl)tetramethyldisiloxane (61.3 g) and octamethylcyclotetrasiloxane (438.7 g) are added.
2. Trifluoromethanesulfonic acid (1.25 g, 0.25 w/w %) is added and stirred 24 hours at room temperature.
3. To the reaction is added sodium bicarbonate (7 g) and the mixture is allowed to stir at a moderate rate for an additional 24 hours at room temperature.
4. The mixture is then filtered with slight positive nitrogen pressure through a pressure filter system equipped with 5 μm PTFE filter and a celite pad into a 1000 mL round bottom flask.
5. The mixture is stirred with a magnetic stir bar and stripped for at least 4 hours at 80° C. and <1.3 mbar using a vacuum pump and acetone/dry ice trap, or until collection of residual octamethylcyclotetrasiloxane is essentially complete (no further collection of liquid) to afford the product as a transparent, colorless, viscous liquid (426 g, 85% yield).
Step 2: Reaction with 2-(methylamino)ethanol
1. The colorless liquid product from step 1.5 above (504 g) was then dissolved in 1,4-dioxane (504 mL, 1 mL dioxane per gram silicone) in a 3-neck 2000 mL round bottom flask. The flask was equipped a mechanical stirring system, a 1 L heating mantle, a water-cooled condenser, and a thermocouple to monitor the reaction temperature. Teflon adapters were used in all of the flask joints to avoid silicone lubricant.
2. 2-(methylamino)ethanol (76 mL, 6 mol eq.) was added to the reaction vessel.
3. The reaction was placed under a nitrogen blanket.
4. The reaction was then heated for 8 hours at 100° C. and stirred sufficiently.
5. The contents of the flask were transferred to a 1-neck 2000 mL round bottom flask and dioxane was removed via a rotary evaporator.
6. Silicone product was re-dissolved in chloroform (500 mL) and transferred to 4000 mL separatory funnel (unreacted amine can be drained from separatory funnel before washing).
7. Product washed with 2000 mL 50/50 brine/10% sodium bicarbonate solution (2×), followed by a wash with 2000 mL 50/50 brine/water.
8. Silicone product collected from Step 2.7 and dried with sufficient amount of magnesium sulfate.
9. Product was vacuum filtered and solvent removed with a rotary evaporator/vacuum pump.
10. The concentrated product was then filtered with slight positive nitrogen pressure through a pressure filter system equipped with 5 μm PTFE filter into a 1000 mL round bottom flask to afford colorless intermediate product (477.6 g, 95% yield).
11. Product confirmed with NMR spectroscopy.
Step 3: Methacrylation with Methacrylic Anhydride.
1. Silicone product from Step 2.9 (450.8 g) was re-dissolved in anhydrous chloroform (450 mL, 1 mL/g silicone) and transferred to a minimum of a 2-neck 2000 mL round bottom flask (dried with heat gun) equipped with a overhead mechanical stirrer.
2. Triethylamine (58.9 g, 3 mol eq.) was added to the reaction, along with dimethylamino pyridine (0.017 g, 0.001 mol eq.) and 500 ppm BHT inhibitor relative to Step 2.9 product (112.7 mg).
3. An addition funnel (dried with heat gun) was added to the flask and methacrylic anhydride (67 mL, 3 mol eq.) was added to the funnel along with chloroform to dilute the anhydride (approx. 100 mL). The system was sealed and placed under a nitrogen blanket.
4. The reaction was stirred and the methacrylic anhydride was added drop-wise. After all the anhydride was added, the reaction was allowed to stir 15 hours at ambient temperature.
5. Water (approx. 700 mL) was added to the reaction and allowed to stir until all the anhydride had converted to methacrylic acid (approx. 15 hours).
6. Reaction transferred to 4000 mL separatory funnel, 700 mL brine added to help separation, and organic layer was isolated.
7. Isolated product layer was washed with 2000 mL 50/50 brine/10% NaHCO3 (×2), followed by 2000 mL 50/50 brine/water.
8. Product transferred to 1-neck 2000 mL RBF and stirred mechanically w/ 200 g Amberlyst A26 hydroxide resin (after resin was washed w/ chloroform) for 48 hours until methacrylic salt absent from product (monitored by NMR). Note: Amberlite IRA-410 CL resin can be substituted for Amberlyst A26 hydroxide resin.
9. Resin separated from product by vacuum filtration.
10. Product dried w/ sufficient amount of magnesium sulfate.
11. Product vacuum filtered and concentrated by rotary evaporator.
12. The concentrated product was then filtered with slight positive nitrogen pressure through a pressure filter system equipped with 5 μm PTFE filter into a 1000 mL round bottom flask to afford intermediate product with slight yellow tint (401 g, 89% yield).
13. Product confirmed via NMR spectroscopy and BHT concentration monitored by Gas Chromatography. The target level for BHT inhibitor is 500 ppm. Appropriate amount of BHT was back-added to methacrylated intermediate product to bring total BHT concentration to 500±100 ppm.
Step #4: Quaternization
[0000]
1. Product from Step 3.10 (250.8 g) dissolved in THF (250 mL, 1.0 mL/g silicone) and transferred to 1-neck 1000 mL round bottom flask with magnetic stir bar.
2. Iodomethane (2.2 mol eq.) added to reaction.
3. Reaction vessel sealed with Teflon stopper and stirred in a 45° C. water bath for 7 hours.
4. System placed on a rotary evaporator to remove solvent and excess iodomethane to afford a yellow, waxy solid product.
5. Product was sealed and allowed to harden at approx. −20° C. for at least 2 hours.
6. Product moved to dry box with dry air environment (≦5% relative humidity) to be chopped/scraped with spatula until very fine in consistency.
7. Residual iodomethane/solvent removed with vacuum pump (1.0×10 −2 mbar, product kept at ambient temperature).
8. Product moved back to dry box for transferring, sampling, etc. and stored at −20° C. with a drying agent to prevent moisture contamination (255.01 g yield).
9. Product confirmed by NMR spectroscopy, Mass Spectrometry and Gel Permeation Chromatography. BHT concentration monitored by Gas Chromatography and residual Iodomethane concentration monitored by Liquid Chromatography.
EXAMPLE 4
Preparation of Film Using Monomer of Example 2
[0323]
[0000]
Parts by weight
RD-1862 (Iodo salt form)
9.30
NVP
41.85
TRIS
23.25
HEMA
18.6
Propylene Glycol
5.00
SA
1.50
v-64
0.50
IMVT
95
ppm
[0324] 40 uL aliquots of a soluble, liquid monomer mix containing 9.3 parts by weight of the product from example 2, 23.3 parts TRIS, 41.9 parts NVP, 18.6 parts HEMA, 5 parts PG, 0.5 parts v-64, 1.5 parts SA, and 95 ppm IMVT were sealed between poly(propylene) anterior and posterior contact lens moulds under an inert nitrogen atmosphere, transferred to an oven and heated under an inert nitrogen atmosphere 2 h at 100° C. The cooled mold pairs were separated and the dry lens released from the mold, hydrated/extracted twice in deionized H2O for a minimum of 3 min, transferred to and sealed in an autoclave vial containing a buffered saline solution and autoclaved 30 min at 121° C. affording optically transparent, blue-tinted ophthalmic lenses.
EXAMPLE 5
Preparation of Film Using Monomer of Example 3
[0325]
[0000]
RD#
Parts
M 2 D 39 plus
1862
5.30
M1-MCR-C12
1876
3.00
NVP
58
43.35
TRIS
142
20.25
HEMA
134
18.6
UV blocker
969
1.50
vaso-64
N/A
0.50
Reactive blue
322
95
ppm
EXAMPLE 6
Preparation of Film Using Monomer of Formula (III)
[0326]
[0000]
Parts
M 2 D 39 plus (Bromo salt form)
9.30
NVP
41.85
TRIS
23.25
HEMA
18.6
Propylene Glycol
5.00
SA
1.50
v-64
0.50
IMVT
95
ppm
[0327] 40 uL aliquots of a soluble, liquid monomer mix containing 9.3 parts by weight of monomer of formula III, 23.3 parts TRIS, 41.9 parts NVP, 18.6 parts HEMA, 5 parts PG, 0.5 parts v-64, 1.5 parts SA, and 95 ppm IMVT were sealed between poly(propylene) anterior and posterior contact lens moulds under an inert nitrogen atmosphere, transferred to an oven and heated under an inert nitrogen atmosphere 2 h at 100° C. The cooled mold pairs were separated and the dry lens released from the mold, hydrated/extracted twice in deionized H2O for a minimum of 3 min, transferred to and sealed in an autoclave vial containing a buffered saline solution and autoclaved 30 min at 121° C. affording optically transparent, blue-tinted ophthalmic.
EXAMPLE 7
Properties of Films of Examples 4 and 6
[0328]
[0000]
Modulus
Tensile
Elong
Tear
Sample
(GM/SQMM)
(GM/SQMM)
(%)
(GM/MM)
Example 3
111 (4)
35 (7)
38 (9)
3 (0)
Example 4
116 (8)
62 (12)
76 (15)
4 (0)
Standard deviation is given within the parenthesis.
EXAMPLE 8
Preparation of Film Using Monomer of Example 2
[0329]
[0000]
Parts
RD-1862 (Iodo salt form)
6.30
M1D11
3.00
NVP
41.85
TRIS
23.25
HEMA
18.6
Propylene Glycol
5.00
SA
1.50
v-64
0.50
IMVT
95
ppm
[0330] 40 uL aliquots of a soluble, liquid monomer mix containing 6.3 parts by weight of the product from example 2, 3.00 parts of a monomethacrylated polydimethyl siloxane prepolymer, 23.3 parts TRIS, 41.9 parts NVP, 18.6 parts HEMA, 5 parts PG, 0.5 parts v-64, 1.5 parts SA, and 95 ppm IMVT were sealed between poly(propylene) anterior and posterior contact lens moulds under an inert nitrogen atmosphere, transferred to an oven and heated under an inert nitrogen atmosphere 2 h at 100° C. The cooled mold pairs were separated and the dry lens released from the mold, hydrated/extracted twice in deionized H2O for a minimum of 3 min, transferred to and sealed in an autoclave vial containing a buffered saline solution and autoclaved 30 min at 121° C. affording optically transparent, blue-tinted ophthalmic lenses.
EXAMPLE 9
Properties of Films of Example 7
[0331]
[0000]
Modulus
Tear
Sample
(GM/SQMM)
(GM/MM)
Example 8
77 (6)
3 (0)
Standard deviation is given within the parenthesis.
|
This application is directed toward an improved method of synthesizing cationic siloxane prepolymers as well as a specific cationic siloxane prepolymer having improved compatibility with monofunctional siloxanyl methacrylate monomers and medical devices containing the cationic siloxane prepolymer.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and incorporates herein by reference Japanese Patent Application No. 2004-118126 filed on Apr. 13, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Application
[0003] The present invention relates to a rotation detection apparatus which detects rotation information concerning a rotor that is formed of a magnetic material, and which utilizes magnetoresistive element (MREs) which change in resistance in response to changes in an applied magnetic field.
[0004] 2. Description of Prior Art
[0005] Types of rotation detection apparatus which utilize MREs are known, for example for obtaining information concerning rotation of a toothed rotor that is provided on the crankshaft or camshaft of an internal combustion engine of a vehicle. Such a type of rotation detection apparatus includes a bias magnet, which produces a bias magnetic field that links with the rotor, and one or more MREs that change in resistance in accordance with changes in a vector of the bias magnetic field. These changes in the magnetic field are processed electrically, to thereby detect changes in the rotation position of the rotor which is the detection object. That is to say, the magnetic vector of the bias magnetic field that links with the detection object (rotor) has periodic angular variations in accordance with the passage of protrusion portions of the rotor periphery and recessed portions of that periphery through the bias magnetic field, as the rotor rotates. The resistances of the MREs vary in accordance with these variations in the magnetic vector of the bias magnetic field, and so vary in accordance with the passing of the protrusion portions and recessed portions of the rotor.
[0006] In general with such a rotation detection apparatus, a plurality of MREs are mounted in a sensor chip, and the angular variations of the magnetic vector will differ in accordance with the size of the air gap between the sensor chip and the rotor periphery. That is to say, for the same amount of angular rotation, of the same rotor, the amount of angular variation of the magnetic vector will differ in accordance with the air gap. On the other hand, for the same rotor, if the air gap is altered then it is found that there is a specific “air gap characteristic minimum point”, which is a specific value of magnetic vector angle (corresponding to some specific size of air gap) for which the amounts of increase and decrease of magnetic vector angle with respect to that specific angle (as the rotor rotates) are of equal magnitude. The variations in the magnetic vector angle result in corresponding variations in an output detection signal indicative of changes in rotation angle of the rotor, and the value of output detection signal corresponding to the air gap characteristic minimum point is appropriate for use as a threshold value, for use in converting the output detection signal to a binary signal.
[0007] Hence it would be desirable to provide a rotation detection apparatus whereby the air gap characteristic |minimum point is held constant, irrespective of changes in the shape of the rotor. If such a type of rotation detection apparatus were available, then operations such as setting of individual detection threshold values in accordance with different shapes of rotor would be substantially reduced.
[0008] In that regard, as described for example in Japanese patent publication No. 2003-269995, a type of rotation detection apparatus is known whereby the aforementioned air gap characteristic minimum point is held constant irrespective of rotor shape. With that prior art rotation detection apparatus, a sensor chip is used having an array of four sets of four MREs. Each set of four MREs are connected in series between a power supply voltage and a reference (ground) potential, with a median voltage-divided output being extracted (i.e., whose value would be ½ of the power supply potential, if all four MREs have identical resistance values). Such a median voltage-divided output will be referred to in the following as the median output potential of such a set of MREs. Variations in the median output potential can be used to derive rotation information concerning a rotor.
[0009] FIG. 21 shows the configuration of that prior art rotation detection apparatus. As shown, the apparatus includes a sensor chip 104 having a row of four sets of four MREs, the sets respectively designated as A, B, C, D. Each set of four MREs is arranged, as shown, in a square configuration, interconnected such that current first flows successively through a first diagonally opposed pair of MREs, then successively through the second diagonally opposed pair of MREs, with a median output potential being produced with respect to the reference (ground) potential. In the following description and in the appended claims, such a set of four MREs, configured physically and electrically substantially as for each of the sets A, B C, D shown in FIG. 21 , will be referred to as a “MRE bridge”, although the electrical configuration is that of a magnetoresistive voltage divider, Respective median output potentials V 1 , V 2 , V 3 , V 4 from these MRE bridges A, B, C, D are inputted to a differential circuit, which performs processing to derive from these a single differential output signal Vd, where Vd=2×(V 3 -V 4 )−(V 1 -V 2 ). By using this differential output signal Vd, the air gap characteristic minimum point can be held constant, irrespective of changes in rotor shape. In the following, “differential output signal” will be abbreviated to “differential output”, for brevity of description.
[0010] FIGS. 22, 23 show the output waveforms of the differential output Vd, for different shapes of rotor. It should be understood that the term “changes in rotor shape” as used herein is intended to signify changes in the respective lengths (as measured around the rotor circumference) of protrusion portions and recessed portions of the rotor periphery, i.e., changes in the respective angular extents (as measured with respect to the rotor axis as center) of the protrusion portions and recessed portions. Similarly, the terms “narrow/wide” as applied herein to protrusion portions or to recessed portions respectively signify “relatively short/relatively long in peripheral extent”, i.e., “relatively small/relatively large in angular extent”.
[0011] FIG. 22 shows examples of waveforms of the differential output Vd (shown expressed in the form of angular variations of the magnetic vector of the bias magnetic field, as described above) for the case in which both the protrusion portions and the recessed portions of the rotor that is the detection object are relatively narrow. The differential output Vd changes in accordance with the angular variation of the vector of the bias magnetic field, and Vd is expressed in FIG. 22 in terms of the angular variation of that vector. As can be understood from FIG. 22 , the air gap characteristic minimum point. (expressed as a value of magnetic vector angle) is approximately 10° with this example.
[0012] FIG. 22 shows examples of waveforms of the differential output Vd (again expressed as variations in the magnetic field vector angle) for the case in which both the protrusion portions and the recessed portions of the rotor that is the detection object are relatively wide. Here again, it is found that the air gap characteristic minimum point is approximately 10°.
[0013] Thus, by using a set of four MRE bridges in that way, obtaining the differential output Vd from the four output voltages of these MRE bridges, as Vd=2×(V 3 -V 4 )−(V 1 -V 2 ), the air gap characteristic minimum point remains substantially constant, irrespective of changes in the shape of the rotor. Hence, if the value of the air gap characteristic minimum point is used as a threshold value for converting the differential output Vd to a binary signal, rotation information concerning the rotor can be easily and accurately detected.
[0014] However as is clear from FIGS. 22, 23 , as the shape of the rotor is changed, the waveform of the differential output Vd also changes accordingly. For example with the rotor shape of FIG. 22 , the waveform of the differential output Vd changes in a sinusoidal manner in accordance with the passing of the protrusion portions and recessed portions of the rotor periphery. However with the rotor shape of FIG. 23 , the waveform of the differential output Vd exhibits abrupt changes between high and low values, due to the phenomenon of magnetic distortion.
[0015] FIG. 24 shows examples of waveforms of the differential output Vd (again expressed as variations in the magnetic field vector), for different rotor shapes and different sizes of the air gap. These show the following:
(a) In the case of the rotor shape designated as Sa (having relatively narrow protrusion portions and recessed portions), it can be understood that the maximum and minimum regions of the differential output Vd characteristic respectively correspond to the protrusion portions and recessed portions of the rotor. (b) In the case of the rotor shape designated as Sb (having relatively narrow protrusion portions and relatively wide recessed portions), it can be understood that the regions of the differential output Vd that correspond to the protrusion portions of the rotor show a relatively sinusoidal variation. However the regions of the differential output Vd that correspond to the recessed portions of the rotor are greatly attenuated at positions corresponding to the centers of these recessed portions. (c) In the case of the rotor shape designated as Sc (in which both the protrusion portions and the recessed portions are relatively wide) it can be understood that the waveform of the differential output Vd falls abruptly at the respective center positions of the protrusion portions and the recessed portions of the rotor.
[0019] For convenience of description, the rotor shapes Sa, Sb, Sc illustrated in FIG. 24 will be referred to in the following as the narrow-protrusion rotor, the equal-pitch rotor and the wide-protrusion rotor, respectively.
[0020] Since the waveform of the differential output Vd varies as described above in accordance with the shape of the rotor, this results in slight variations in the degree of latitude (as defined hereinafter) and angular accuracy of detecting rotation information for a rotor based on the differential output Vd, The concepts of “degree of latitude” and “angular accuracy” as used herein will be described referring to FIGS. 25 and 26 .
[0021] FIG. 25 illustrates the relationship between the waveform of the differential output Vd and various types of air gap, for describing the concept of “degree of latitude”. As shown in FIG. 25 , as the air gap becomes larger, the amplitude of the differential output Vd becomes smaller, and reaches a minimum value at positions corresponding to the centers of the protrusion portions and the recessed portions of the rotor.
[0022] Considering:
(a) the difference between the minimum value of the differential output Vd that corresponds to a protrusion portion of the rotor (i.e., that is produced while a protrusion portion of the rotor periphery is moving past the MREs) and the air gap characteristic minimum point, and (b) the difference between the minimum value of differential output Vd that corresponds to a recessed portion of the rotor and the air gap characteristic minimum point; the smaller of these two values of difference with respect to the air gap characteristic minimum point constituting the “degree of latitude”.
[0026] When the degree of latitude falls below a predetermined level, then errors will occur in the detection pulses that are derived by the rotation detection apparatus, so that errors will arise in the rotation information that is derived by the apparatus.
[0027] FIG. 26 is a diagram for describing the concept of “angular accuracy” as used herein in describing a rotation detection apparatus. Specifically, FIG. 26 shows a magnified portion of the differential output Vd waveform (i.e., as represented by the angular variation of the bias magnetic field vector) of FIG. 25 (designated as the region S, in FIG. 25 ). In FIG. 26 , the bias magnetic field vector angle corresponding to both the point of intersection PI between the waveforms of the differential output Vd for the case of a “small” air gap and the point of intersection P 2 for the case of a “medium” air gap is the air gap characteristic minimum point. There is an angular difference Δα (=α 1 −α 2 ) between the rotor rotation angles a 1 and a 2 that respectively correspond to the intersection points P 1 and P 2 , and this angular difference Δα constitutes the “angular accuracy”, as used herein in describing a rotation detection apparatus.
[0028] Alternatively stated, the angular accuracy is the degree of accuracy with which rotor rotation angles are attained that respectively correspond to coincidence between the amplitude of the differential output Vd (as the rotor rotates) and the value of Vd corresponding to the air gap characteristic minimum point.
[0029] Since the waveform of the differential output Vd varies in accordance with rotor shape, the degree of latitude and angular accuracy in detecting the rotation information also change accordingly. Thus for example when a rotation detection apparatus is used for detecting rotation of the crankshaft or camshaft of the internal combustion engine of a vehicle, the requirements for the degree of latitude and for the angular accuracy will differ, depending upon whether rotation of the crankshaft or rotation of the camshaft is to be detected.
[0030] Specifically, in the case of detection of rotation of a camshaft, a rotor (coupled to the camshaft) that is used in conjunction with a rotation detection apparatus will generally be formed with relatively wide peripheral protrusions, for the purpose of accurately discriminating between the respective cylinders of the internal combustion engine. Thus in such an application, a large degree of latitude is more important than a high angular accuracy.
[0031] In the case of detection of rotation of a crankshaft on the other hand, a rotor (coupled to the crankshaft) that is used in conjunction with a rotation detection apparatus will generally be formed with relatively narrow peripheral protrusions, for the purpose of accurately detecting the rotation angle of the crankshaft. Thus in such an application, a high angular accuracy is more important than a large degree of latitude.
[0032] With a prior art type of rotation detection apparatus, it has not been possible to readily design the apparatus to have optimum rotation detection characteristics for use in such different forms of application.
SUMMARY OF THE INVENTION
[0033] It is an objective of the present invention to overcome the above problem by providing a rotation detection apparatus, and a method of designing such an apparatus, which enable optimization of the rotation detection characteristics of the apparatus in accordance with the shape of a rotor that is the detection object of the rotation detection apparatus. The invention provides a rotation detection apparatus which can be utilized for detecting a rotation condition of a rotor that is formed of a magnetic material and has a circumferential periphery having successively alternating protruding portions and recessed portions, with the apparatus including a sensor chip having a plurality of MREs and a bias magnet for applying a bias magnetic field to the MREs, and with detection being performed by sensing changes in resistance values of the MREs due to changes in a magnetic vector of the bias magnetic field as the circumferential periphery of the rotor rotates close to the sensor chip.
[0034] To achieve the above objectives, according to a first aspect, the apparatus is configured with the MREs of the sensor chip arranged and connected as an array of at least four MRE bridges (where the term “MRE bridge” as used in the description of the present invention and the appended claims has the specific significance that has been defined hereinabove referring to FIG. 21 ) having an orientation determined by the rotation direction of the rotor. Designating a “first distance” as the distance between an end face of the bias magnet that is located directly opposite the circumferential periphery of the rotor (i.e., with that end face being used as a position reference) and each of respective centers of at least two MRE bridges which are located at inward positions within the array of MRE bridges (in relation to the central magnetic axis of the bias magnet), and designating a “second distance” as the distance between the reference end face of the bias magnet and each of respective centers of at least two MRE bridges which are located at outward positions within the array of MRE bridges, values for the first distance and second distance are respectively separately set.
[0035] With such a rotation detection apparatus, when the direction of the magnetic vector is altered, changes occur in the median output potentials of the outer pair of MRE bridges that are different from resultant changes which occur in the median output potentials of the inner pair of MRE bridges. However in addition, the assignee of the present invention has found that, by adjusting the aforementioned first distance and second distance respectively separately, it is possible to thereby effect changes in the median output potentials of the outer pair of MRE bridges that are different from resultant changes which occur in the median output potentials of the inner pair of MRE bridges. It has thereby been found possible to alter the aforementioned degree of latitude and angular accuracy, by suitable performing such position adjustments. It thereby becomes possible to realize a rotation detection apparatus whose rotation detection characteristics can be optimized for use with each of various different configurations of rotor, e.g., the aforementioned narrow-protrusion rotor configuration, or equal-pitch rotor configuration, or wide-protrusion rotor configuration.
[0036] Such a rotation detection apparatus preferably comprises differential circuit means for generating a signal referred to herein as the “main component” signal, based on the difference between respective median output potentials of the at least two MRE bridges which are located at inward positions in relation to a central magnetic axis of the bias magnet, a signal referred to herein as the “compensation component” signal, based on the difference between respective median output potentials of the at least two MRE bridges which are located at outward positions in relation to the central magnetic axis, and a single differential output signal (constituting an output detection signal which conveys rotation information concerning the rotor) based on a difference between the main component signal and the compensation component signal, with the aforementioned first distance and second distance being respectively separately set such that the waveform of the single differential output signal attains a condition predetermined in accordance with the configuration of the rotor periphery. This further enables the rotation detection characteristics to be optimized for use with each of various different configurations of rotor,
[0037] As described above, the single differential output signal will in general converted to a binary signal before being utilized, with the conversion executed using a specific threshold value. The aforementioned condition that is predetermined for the waveform of the single differential output signal in accordance with the rotor configuration can be that the degree of latitude (as defined hereinabove) will attain a predetermined standard. In that which case, respective values for the aforementioned first distance and second distance are established such as to have the relationship:
first distance<second distance.
[0038] Alternatively, the condition that is predetermined for the waveform of the single differential output signal can be that the angular accuracy (as defined hereinabove) of the apparatus will be substantially high. In that case, the aforementioned first distance and second distance are respectively set such as to have the relationship:
first distance>second distance.
[0039] The rotation detection apparatus can thereby be optimized for use with a narrow-protrusion rotor or an equal-pitch rotor, i.e., so that a high degree of accuracy of edge detection is required. Achieving a sufficiently high degree of angular accuracy (as defined hereinabove) ensures that such high accuracy of edge detection can be achieved.
[0040] As a further alternative, it may be necessary to ensure that both the degree of latitude and the angular accuracy each attain predetermined standards, i.e., each is sufficiently high. In that case, again, the first distance and second distance are respectively set such as to have the relationship:
first distance>second distance.
[0041] According to a further aspect, with the rotation detection apparatus having first, second and third differential amplifiers for respectively deriving the aforementioned compensation component signal, main component signal, and single differential output signal, respective predetermined appropriate amplification factors are set for the first differential circuit, second differential circuit and third differential circuit.
[0042] This enables the rotation detection characteristics of the rotation detection apparatus to be optimized for a particular type of rotor configuration, by means of an electrical form of adjustment (i.e., of amplifier gain values), rather than by physically altering the positions of MRE bridges. This type of electrical adjustment also enables suitable values to be established for the degree of latitude and the angular accuracy (as defined hereinabove), for various different forms of rotor configuration.
[0043] Specifically, the respective amplification factors of the first differential circuit, second differential circuit and third differential circuit can be separately set such that the waveform of the single differential output signal attains a condition predetermined in accordance with the configuration of the rotor periphery.
[0044] In particular, when the condition that is predetermined for the waveform of the single differential output signal is that the degree of latitude attain a predetermined standard, then designating the respective amplification factors of the first differential circuit and second differential circuit as K 1 and K 2 , and designating respective amplitude values of the main component signal and the compensation component signal as A 1 and A 2 , values for K 1 , K 2 are respectively set such that the following relationship is satisfied:
( K 1 × A 1 − K 2 × A 2 )>(2 ×A 1 − A 2 ).
[0045] The waveform of the single differential output signal can thereby be increased in amplitude, by reducing the amplitude of the compensation component, thereby enabling a higher degree of latitude to be achieved.
[0046] As a further alternative, the condition that is predetermined for the waveform of the single differential output signal is that the angular accuracy (as defined hereinabove) attain a predetermined standard. In that case this can be achieved by setting values for K 1 , K 2 respectively such that the following relationship is satisfied:
K 1 / K 2 <2.
[0047] As yet a further alternative, it may be that the condition that is predetermined for the waveform of the single differential output signal is that both a large degree of latitude and high angular accuracy are to be achieved. In that case again, values for K 1 , K 2 are respectively set such that the above relationship is satisfied, i.e.:
K 1 / K 2 <2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] FIG. 1 is a diagram showing the general configuration of a first embodiment of a rotation detection apparatus, and a rotor which is the detection object of the apparatus;
[0049] FIG. 2 is a plan view conceptually illustrating the configuration of a sensor chip of the first embodiment;
[0050] FIG. 3 is a circuit diagram of a differential amplifier circuit of the first embodiment;
[0051] FIG. 4 shows graphs illustrating relationships between positions of MRE bridges and a degree of latitude, for the first embodiment;
[0052] FIG. 5 shows graphs illustrating relationships between changes in rotor configuration and angular accuracy, for the first embodiment;
[0053] FIGS. 6A to 6 C show graphs illustrating the relationship between positions of MRE bridges and waveforms corresponding to those of a differential output Vd, a compensation component of the differential output Vd, and a main component of the differential output Vd, for the case of a wide-protrusion rotor being the detection object of the rotation detection apparatus;
[0054] FIG. 7 is a diagram showing the general configuration of a second embodiment of a rotation detection apparatus, and a rotor which is the detection object of the apparatus;
[0055] FIG. 8 is a plan view conceptually illustrating the configuration of a sensor chip of the second embodiment;
[0056] FIG. 9 shows graphs illustrating relationships between positions of MRE bridges and a degree of latitude, for the second embodiment;
[0057] FIGS. 10A to 10 C show graphs illustrating the relationship between positions of MRE bridges and waveforms corresponding to those of a differential output Vd, for the case of a narrow-protrusion rotor being the detection object of the rotation detection apparatus;
[0058] FIGS. 11A to 11 C show expanded views of portions of FIGS. 10A to 10 C respectively, for use in describing a concept of angular accuracy, as used in describing the present invention;
[0059] FIG. 12 is a diagram showing the general configuration of the second embodiment when an equal-pitch rotor is the detection object of the apparatus;
[0060] FIG. 13 shows graphs illustrating relationships between positions of MRE bridges and a degree of latitude, for the case of the second embodiment being applied to an equal-pitch rotor as the detection object of the apparatus;
[0061] FIG. 14 is a plan view conceptually illustrating the configuration of a sensor chip of a third embodiment of a rotation detection apparatus;
[0062] FIG. 15 is a circuit diagram of a differential amplifier circuit of the third embodiment;
[0063] FIG. 16 shows graphs illustrating relationships between positions of MRE bridges and a degree of latitude, for the third embodiment, for the case of a wide-protrusion rotor being the detection object of the apparatus;
[0064] FIG. 17 shows graphs illustrating relationships between various different rotor configurations and angular accuracy, for the third embodiment;
[0065] FIGS. 18A to 18 C show graphs illustrating the relationship between changes in the amplification factor of a differential amplifier which derives the compensation component of the differential output Vd and waveforms corresponding to those of the differential output Vd, the compensation component, and the main component of Vd;
[0066] FIG. 19 is a circuit diagram of a differential circuit of a fourth embodiment of a rotation detection apparatus;
[0067] FIG. 20 shows graphs illustrating relationships between changes in the amplification factor of a differential amplifier which produces the compensation component of the differential output Vd and the degree of latitude, for the fourth embodiment, for the case of a narrow-protrusion rotor being the detection object of the apparatus;
[0068] FIG. 21 is a plan view conceptually illustrating the configuration of a sensor chip of prior art example of a rotation detection apparatus;
[0069] FIG. 22 shows waveforms of an output detection signal produced by the prior art rotation detection apparatus, for the case of a narrow-protrusion rotor being the detection object of the apparatus;
[0070] FIG. 23 shows waveforms corresponding to an output detection signal produced by the prior art rotation detection apparatus, for the case of a wide-protrusion rotor being the detection object of the apparatus;
[0071] FIG. 24 shows waveforms corresponding to an output differential signal produced by the prior art rotation detection apparatus, for respectively different configurations of rotor;
[0072] FIG. 25 shows waveforms of an output differential signal, for use in defining the concept of an air gap characteristic minimum point, as used in describing the present invention; and
[0073] FIG. 26 shows waveforms of an output differential signal, for use in defining the concept of angular accuracy, as used in describing the present invention
DESCRIPTION OF PREFERRED EMBODIMENTS
First Embodiment
[0074] A first embodiment will be described referring to FIGS. 1 to 6 . This is a rotation detection apparatus which can be optimized for use with a specific detection object, for example a rotor coupled to the camshaft of an internal combustion engine, with the rotor being formed with relatively wide protrusion portions (as defined hereinabove), for enabling discrimination of respective cylinders of the engine.
[0075] FIG. 1 conceptually illustrates an embodiment of a rotation detection apparatus 1 a , and a rotor 6 which is the detection object of this embodiment, as viewed along the direction of the axis of the rotor 6 . As shown, the rotation detection apparatus 1 a includes a bias magnet 2 , for producing a bias magnetic field, which is disposed opposite the circumferential periphery of the wide-protrusion rotor 6 . The wide-protrusion rotor 6 is a wide-protrusion rotor, formed of a magnetic material. A sensor chip 3 a , formed of an array of MRE bridges, is mounted in a face of the bias magnet 2 located opposite the circumferential periphery of the wide-protrusion rotor 6 , as shown (with the sensor chip 3 a shown as protruding from that face, in the conceptual diagram of FIG. 1 , for ease of understanding). Specifically, a cavity is formed in that face of the bias magnet 2 , and the sensor chip 3 a is fixedly attached within that cavity.
[0076] The body of the sensor chip 3 a can for example be formed by molding, using a thermally hardened type of synthetic resin such as epoxy resin.
[0077] The bias magnet 2 is disposed with its central magnetic axis (which coincides with the central axis of the sensor chip 3 a ) oriented such as to pass through the rotation axis of the wide-protrusion rotor 6 . In that way, the bias magnetic field that is produced by the bias magnet 2 has a magnetic vector that exhibits a periodic angular variation in accordance with rotation of the wide-protrusion rotor 6 . The angular variation of the magnetic vector is sensed by the MRE bridges of the sensor chip 3 a , whose respective resistance values vary accordingly. These variations in resistance value of the MRE bridges result in changes in the respective median output potentials of the MRE bridges, and the rotation detection apparatus 1 a includes a differential circuit 5 which performs differential processing of these changes in the median output potentials of the MRE bridges. The array of MRE bridges A to D is oriented in accordance with the rotation axis of the rotor 6 , i.e., with respective centers of the MRE bridges being located substantially within a plane that is at right angles to the rotation axis of the rotor 6 .
[0078] FIG. 2 is a plan view showing the general configuration of the sensor chip 3 a , and in particular showing a sensor section of the sensor chip 3 a . As shown in FIG. 2 , the sensor chip 3 a includes an array of four MRE bridges, respectively designated as A, B, C and D. The two outer MRE bridges A and B are located symmetrically on opposing sides of the aforementioned central magnetic axis of the bias magnet 2 , designated by numeral 20 . The two inner MRE bridges C and D are also located symmetrically on opposing sides of central magnetic axis 20 , with the MRE bridge C being located midway between the center of the MRE bridge A and the central magnetic axis 20 , and the MRE bridge D being located midway between the center of the MRE bridge B and the central magnetic axis 20 .
[0079] In addition, as also shown in FIG. 2 , the distance L 1 between the centers of the MRE bridges A and C, the distance L 4 between the centers of the MRE bridges D and B, the distance L 2 between the center of the MRE bridge C and the central magnetic axis 20 , and the distance L 2 between the center of the MRE bridge D and the central magnetic axis 20 (with each of the distances L 1 , L 2 , L 3 , L 4 measured along a direction at right angles to the central magnetic axis 20 ) are respectively identical. Hence, the array of MREs A to D has a predetermined orientation with respect to the rotation axis of the rotor 6 .
[0080] With this embodiment, the outer pair of MRE bridges A and B are disposed farther from the face of the bias magnet 2 that opposes the wide-protrusion rotor 6 (with that face of the bias magnet 2 being referred to as the “rotor-side face” in the following) than the inner pair of MRE bridges C and D. Specifically, the distance D 2 between the respective centers of the MRE bridges A and B and the rotor-side face of the bias magnet 2 is made longer than the distance D 1 between the respective centers of the MRE bridges C and D and that rotor-side face (D 2 >D 1 ).
[0081] Variations in the angle of the magnetic vector of the bias magnet 2 are detected as changes in resistance of the MREs of the MRE bridges A, B, C, D, which are extracted as corresponding changes in their respective median output potentials. These four median output potentials (i.e., the outputs shown as V 1 , V 2 , V 3 , V 4 from the MRE bridges A, B, C and D respectively as indicated in FIG. 2 ) are inputted to the differential circuit 5 as shown in the circuit diagram of FIG. 3 .
[0082] The differential circuit 5 is formed of three differential amplifiers, A 1 , A 2 and A 3 . The differential amplifier A 1 has a amplification factor of 2, so that the median output potentials V 3 , V 4 from the MRE bridges C and D result in a differential output of [2×(V 3 −V 4 )] being produced from the differential amplifier Al. The differential amplifiers A 2 , A 3 each have an amplification factor of 1, so that the median output potentials V 1 , V 2 from the MRE bridges A and B result in a differential output of (V 1 −V 2 ) being produced from the differential amplifier A 2 . These differential outputs from the differential amplifiers A 1 , A 2 are inputted to the differential amplifier A 3 , which thereby produces a single differential output Vd, where the amplitude of Vd is obtained as [2×(V 3 −V 4 )−(V 1 −V 2 )].
[0083] With this embodiment, rotation information concerning the wide-protrusion rotor 6 is obtained based on this single differential output Vd.
[0084] In that way, the differential circuit 5 produces an output signal having two components, i.e.,:
{2×(V 3 −V 4 )}, designated in the following as the main component, which is derived from the median output potentials of the MRE bridges C and D, and (V 1 −V 2 ), designated in the following as the compensation component, which is derived from the median output potentials of the MRE bridges A and B.
[0087] Thus, by altering the amplitude of the waveform of the compensation component in relation to that of the main component, it becomes possible to alter the differential output Vd to have a desired amplitude or shape of waveform.
[0088] It should be noted that with this embodiment, by locating two outer MRE bridges A and B (from which the compensation component of Vd is derived) at positions which are farther from the rotor-side face of the bias magnet 2 than the two inner MRE bridges C and D, the amplitude of the compensation component of Vd is accordingly reduced, i.e., the amplitude of the single differential output Vd is accordingly increased. In that way, the wide-protrusion rotor 6 can reliably have a high degree of latitude (as defined hereinafter) in rotation information detection, when the detection object of the rotation detection apparatus 1 a is the wide-protrusion rotor 6 .
[0089] The relationship between the respective locations of the MRE bridges A and B and the aforementioned degree of latitude will be described referring to the graphs of FIG. 4 . In FIG. 4 , results of electromagnetic simulation are shown for the cases in which the MRE bridges A to D have the following respective predetermined positions:
(a) The MRE bridges A, B are located at respective positions each of which is farther from the rotor-side face of the bias magnet 2 than the positions of the MRE bridges C and D (i.e., D 2 >D 1 ). (b) The MRE bridges A to D are arrayed in a single row (i.e., D 2 =D 1 ). (c) The MRE bridges A, B are located at respective positions each of which is closer to the rotor-side face of the bias magnet 2 than the positions of the MRE bridges C and D (i.e., D 2 <D 1 ).
[0093] As is clear from FIG. 4 , for the same size of air gap, the highest degree of latitude is obtained for case (a) above, (D 2 >D 1 ), with the MRE bridges A and B positioned farther from the rotor-side face of the bias magnet 2 than the MRE bridges C and D. With case (c) above (D 2 <D 1 ), whereby the MRE bridges A, B are located at positions closer to the rotor-side face of the bias magnet 2 than the positions of the MRE bridges C and D, the degree of latitude is substantially lowered, by comparison with case (a). Overall, the greater the distance D 2 of the MRE bridges A and B from the rotor-side face of the bias magnet 2 , the higher becomes the degree of latitude. Furthermore, as the size of the air gap is increased, the degree of latitude decreases accordingly.
[0094] As is clear from the simulation results shown in FIG. 4 , if the MRE bridges A, B are set at positions closer to the rotor-side face of the bias magnet 2 then the MRE bridges C, D, and the air gap is made large, then the degree of latitude will fall below a standard value (i.e., degree of latitude=1). This standard value corresponds to a value of the differential output Vd that is necessary to ensure that error pulses will not be produced when the differential output Vd is converted to a binary signal.
[0095] In that way, the positions at which the MRE bridges are located will have a large effect on the degree of s latitude of detection of rotation information by the rotation detection apparatus 1 a . In the case of the wide-protrusion rotor 6 being the detection object, if the MRE bridges A, B are positioned farther from the rotor-side face of the bias magnet 2 than the MRE bridges C, D, then the degree of latitude is increased.
[0096] On the other hand, the positions at which the MRE bridges A, B are located have an effect on the angular accuracy of rotation information detection. This effect is illustrated in the magnetic simulation results shown in the graphs of FIG. 5 , which show results obtained for the case of a narrow-protrusion rotor and the case of a equal-pitch rotor being respective detection objects, as well as for the case of the wide-protrusion rotor 6 .
[0097] It can be understood from FIG. 5 that irrespective of the rotor shape, when the MRE bridges A and B are located closer to the rotor-side face of the bias magnet 2 than the MRE bridges C and D (i.e., D 2 <D 1 ), the angular accuracy is increased. Furthermore, the smaller the distance D 2 between the NRE bridges A, B and the rotor-side face of the bias magnet 2 , the higher becomes the angular accuracy. Furthermore, for the same value of distance D 2 , the highest degree of angular accuracy is obtained when the narrow-protrusion rotor is the detection object. Specifically, the angular accuracy successively decreases in the order: narrow-protrusion rotor→equal-pitch rotor→wide-protrusion rotor.
[0098] However as described above, in the case of the wide-protrusion rotor 6 being used in conjunction with the camshaft of an internal combustion engine for discriminating the engine cylinders, a high degree of latitude is more important than a high level of angular accuracy. This is due to the fact that in such an application, after engine starting has been completed, it is only necessary to detect rotation angle information once, for discriminating the engine cylinders. Also, from mechanical considerations, it is preferable to make the degree of degree of tolerance for the air gap size as large as possible. For that reason, with this embodiment, a high degree of latitude is achieved, which is done to some extent at the expense of angular accuracy.
[0099] FIG. 6A to 6 C are diagram showing relationships between the main component and the compensation component which constitute the differential output Vd, and the locations of the MRE bridges A and B, for the case of the wide-protrusion rotor 6 being the detection object. FIG. 6A shows waveforms of the differential output Vd, and its main component and compensation component, for the case in which the MRE bridges A, B are closer to the rotor-side face of the bias magnet 2 than the MRE bridges C and D (i.e., D 2 <D 1 ). FIG. 6B shows waveforms of the differential output Vd, and its main component and compensation component, for the case in which the MRE bridges A, B, C and D are aligned in a row (i.e., D 2 =D 1 ). FIG. 6C shows waveforms of the differential output Vd, and its main component and compensation component, for the case in which the MRE bridges A, B are located farther from the rotor-side face of the bias magnet 2 than the MRE bridges C and D (i.e., D 2 >D 1 ).
[0100] As is clear from FIGS. GA to 6 C, as the distance of the MRE bridges A, B from the rotor-side face of the bias magnet 2 is increased, the amplitude of the output waveform of the compensation component (V 1 −V 2 ) is decreased. As a result, the amplitude of the differential output Vd is increased. In that way, designating the degree of latitude for FIG. 6A as Wa, the degree of latitude for FIG. 6B as Wb, and the degree of latitude for FIG. 6C as Wc, the relationship between these is:
Wa<Wb<Wc.
[0101] As described above, with this embodiment of a rotation detection apparatus, the following effects are obtained. With the configuration example of FIG. 2 , the MRE bridges A, B are set farther from the rotor-side face of the bias magnet 2 than are the MRE bridges C and D. As a result, the amplitude of the compensation component (V 1 −V 2 ) is decreased, so that the amplitude of the differential output Vd is increased, and so the degree of latitude for detecting rotation information can be appropriately increased, when the wide-protrusion rotor 6 is the detection object.
Second Embodiment
[0102] A second embodiment of a rotation detection apparatus utilizing magnetic detection will be described in the following referring to FIGS. 7 to 12 . This embodiment can be advantageously applied when the detection object is a narrow-protrusion rotor which is utilized, for example, for detection of the rotation angle of a crankshaft of an internal combustion engine.
[0103] With this embodiment, the MRE bridges A and B are disposed closer to the rotor-side face of the bias magnet 2 than the MRE bridges C and D. In other respects, this embodiment is similar to the first embodiment, with components corresponding to those of the first embodiment being designated by corresponding reference numerals to those of the first embodiment, so that detailed description is omitted.
[0104] FIG. 7 conceptually illustrates the overall configuration of this embodiment of a rotation detection apparatus 1 b , and a narrow-protrusion rotor 7 which is the detection object. As shown, the rotation detection apparatus 1 b includes a bias magnet 2 , for producing a bias magnetic field, which is disposed opposite the circumferential periphery of the narrow-protrusion rotor 7 , which in this embodiment is a narrow-protrusion rotor formed of a magnetic material. A sensor chip 3 b , formed of an array of MRE bridges, is mounted in a face of the bias magnet 2 that is opposite the circumferential periphery of the narrow-protrusion rotor 7 .
[0105] FIG. 8 is a plan view illustrating the general configuration of the sensor chip 3 b of this embodiment. As shown, the outer pair of MRE bridges A and B are disposed closer to the rotor-side face of the bias magnet 2 than the inner pair of MRE bridges C and D. Specifically, the distance D 2 between the respective centers of the MRE bridges A and B and the rotor-side face of the bias magnet 2 is made shorter than the distance D 1 between the respective centers of the MRE bridges C and D and that rotor-side face (D 2 <D 1 ).
[0106] With this configuration, the differential output (2×(V 3 −V 4 )) derived from the difference between the respective center-value potentials of the inner pair of MRE bridges C and D constitutes the main component of the differential output Vd, while the differential output (V 1 −V 2 ) derived from the difference between the respective center-value potentials of the outer pair of MRE bridges A and a constitutes the compensation component of the differential output Vd. That is, the single differential output Vd is obtained as:
Vd= 2×( V 3 − V 4 )−( V 1 − V 2 ).
[0107] Rotation information for the narrow-protrusion rotor 7 is detected based on this differential output Vd.
[0108] By disposing the MRE bridges A to D in that way, the compensation component is increased, thereby increasing the accuracy of edge detection of the narrow protrusions of the rotor 7 , so that the accuracy of detecting rotation information concerning the narrow-protrusion rotor 7 is increased. That is to say, as described hereinabove referring to FIG. 5 , the smaller the distance between the MRE bridges A and B and the rotor-side face of the bias magnet 2 , the higher becomes the angular accuracy.
[0109] FIG. 9 shows results of electromagnetic simulation of changes in the degree of latitude for the case of the narrow-protrusion rotor 7 being the detection object, when the positions of the MRE bridges C and D are held fixed at predetermined locations and the positions of the MRE bridges A and B are altered. As shown in FIG. 9 , as the distance of each of the MRE bridges A and B from the rotor-side face of the bias magnet 2 is made smaller, the degree of latitude increases accordingly.
[0110] In that way, when the narrow-protrusion rotor 7 is the detection object, both the angular accuracy and degree of latitude can be optimized by setting the positions of the MRE bridges A and B as close as possible to the rotor-side face of the bias magnet 2 .
[0111] The limitation on positioning the MRE bridges A and B is the point at which the saturation magnetic flux begins to fall below the level that is necessary for stable operation of the MREs. Furthermore, the magnetic field intensity of the bias magnetic field will decrease as the MRE bridges A, B are moved from the center of the central magnetic axis of the bias magnet 2 , along the direction of that central magnetic axis towards the rotor-side face of the bias magnet 2 . Thus, the bias magnetic field strength may become weaker than a level that is necessary for satisfactory operation, if the MRE bridges are located too close to that rotor-side face. For that reason, the respective positions at which the MRE bridges A and B are located should be such as to ensure that the requisite level of saturation magnetic flux (approximately −20 mT) is maintained.
[0112] With this embodiment, the sensor chip 3 b is configured with the MRE bridges A and B located in isomagnetic regions having the saturation magnetic flux.
[0113] However it should be noted that so long as a satisfactory value of saturation magnetic flux can be maintained, it is not essential that each of the MRE bridges A to D be located in isomagnetic regions.
[0114] FIGS. 10A to 10 C show the relationship between the positions at which the MRE bridges A and B are set (i.e., the distance D 2 of each of these MRE bridges from the rotor-side face of the bias magnet 2 ) and the differential output Vd (shown expressed in the form of values of magnetic vector variation angle), for the case of the narrow-protrusion rotor 7 being the detection object of the rotation detection apparatus. FIG. 10A shows waveforms of the differential output Vd for respectively different sizes of the air gap (large, medium, small) for the case in which the MRE bridges A and B are located farther from the rotor-side face of the bias magnet 2 than the MRE bridges C and D (i.e., D 2 >D 1 ). FIG. 10B shows waveforms of the differential output Vd for respectively different sizes of the air gap (large, medium, small) for the case in which all of the MRE bridges A to D are arrayed in a row (i.e., D 2 =D 1 ). FIG. 10C shows waveforms of the differential output Vd for respectively different sizes of the air gap (large, medium, small) for the case in which the MRE bridges A and B are located closer to the rotor-side face of the bias magnet 2 than the MRE bridges C and D (i.e., D 2 <D 1 ).
[0115] In the case of FIGS. 10A to 10 C, the air gap characteristic minimum point corresponds to the magnetic vector variation angle at which intersections occur between the waveform of the differential output Vd when the air gap size is large and the waveform of Vd when the air gap size is small.
[0116] FIGS. 11A to 11 C each show an expanded view of the vicinity of a point of intersection between the respective waveforms of the differential output Vd corresponding to the different sizes of air gap as described for FIGS. 10A to 10 C. As shown in FIG. 11A , in the case in which the MRE bridges A and B are located farther from the rotor-side face of the bias magnet 2 than the MRE bridges C and D (i.e., D 2 >D 1 ), the angular accuracy of rotation detection is the amount designated as Δα 1 , As shown in FIG. 11B , in the case in which the MRE bridges A to D are arrayed in a row (i.e., D 2 =D 1 ), the angular accuracy of rotation detection is Δα 2 . As shown in FIG. 11A , in the case in which the MRE bridges A and B are located closer to the rotor-side face of the bias magnet 2 than the MRE bridges C and D (i.e., D 2 <D 1 ), the angular accuracy of rotation detection is the amount designated as Δα 3 .
[0117] As can be understood from FIGS. 11A to 11 C, the respective values of angular accuracy have the magnitude relationship [Δα 1 >Δα 2 >Δα 3 ]. Hence, the closer the MRE bridges A and B are positioned to the rotor-side face of the bias magnet 2 , the higher will become the angular accuracy, and hence the higher will become the accuracy of rotation detection.
[0118] It can thus be understood that when the narrow-protrusion rotor 7 is the detection object, e.g., used for detection of the rotation speed (rotation angle) of the crankshaft of an internal combustion engine, a high degree of angular accuracy of rotation detection can readily be achieved by positioning the MRE bridges A and B close to the rotor-side face of the bias magnet 2 .
[0119] As can be understood from the above description, with the configuration shown in FIG. 8 for this embodiment whereby the outer MRE bridges A and B are located closer to the rotor-side face of the bias magnet 2 than the inner pair of MRE bridges C and D, the result is obtained that an increase level of angular accuracy of rotation detection is achieved, when the narrow-protrusion rotor 7 is the detection object.
[0120] The above embodiment has been described for the case in which the detection object is a narrow-protrusion rotor that is coupled to rotate with the crankshaft of an internal combustion engine. However in some cases an equal-pitch rotor may be utilized in such an application. As described above, an equal-pitch rotor is configured with the circumferential periphery thereof formed with recessed portions that are longer (i.e., have a greater angular extent) than in the case of a narrow-protrusion rotor. As a result, the angular accuracy and the degree of latitude that are obtained when an equal-pitch rotor is the detection object exhibit different tendencies from those for the case in which a narrow-protrusion rotor is the detection object.
[0121] FIG. 12 shows the general configuration of a rotation detection apparatus 1 c that is utilized with an equal-pitch rotor 8 as the detection object, and also shows the equal-pitch rotor 8 . The rotation detection apparatus 1 c can be configured similarly to the sensor chip 3 b described above, so that detailed description is omitted. That is to say, the MRE bridges A and B are located closer to the rotor-side face of the bias magnet 2 than the inner pair of MRE bridges C and D.
[0122] FIG. 13 shows results of electromagnetic simulation of changes in the degree of latitude for the case of the equal-pitch rotor 8 being the detection object, when the positions of the MRE bridges C and D are held fixed and the positions of the MRE bridges A and B are altered. As shown in FIG. 13 , as the distance of each of the MRE bridges A and B from the rotor-side face of the bias magnet 2 is increased, the degree of latitude increases accordingly. In that respect, the results obtained for the equal-pitch rotor differ from those obtained for the narrow-protrusion rotor. However as is clear from FIG. 13 , even if the distance D 2 of the MRE bridges A and B from the rotor-side face of the bias magnet 2 is relatively small, a substantially high degree of latitude is still obtained, i.e., which is close to the standard value of 1 for the degree of latitude.
[0123] It can thus be understood that if the sensor chip 3 c has the configuration shown in FIG. 8 , then both the angular accuracy and degree of latitude can meet respective requisite standards, when an equal-pitch rotor is the detection object of the rotation detection apparatus.
Third Embodiment
[0124] A third embodiment of a rotation detection apparatus will be described referring to FIGS. 14 to 18 . In the same way as described for the first embodiment above, this embodiment is optimized for use in rotation detection of a wide-protrusion rotor that is coupled for rotation with the camshaft of an internal combustion engine, with the rotation detection apparatus being used to discriminate the respective cylinders of the engine. However with this embodiment, a sensor chip 3 d having the configuration illustrated in FIG. 14 is utilized, in place of the sensor chip 3 a of the first embodiment, and the differential circuit 5 a shown in FIG. 15 is used in place of the differential circuit 5 of the first embodiment.
[0125] As shown in FIG. 14 , the sensor chip 3 d of this embodiment utilizes an array of four MRE bridges A to D, with the respective median output potentials of V 1 , V 2 , V 3 V 4 of the MRE bridges A, B, C, D being inputted to the differential circuit 5 a as shown in FIG. 15 .
[0126] Basically, the differential circuit 5 a is formed of a first differential amplifier A 1 , a second differential amplifier A 2 a , and a third differential amplifier A 3 . Of these, the differential amplifier A 2 a , which produces the compensation component of the differential output Vd, has an amplification factor of 0.6, and produces a differential output 10.6×(V 1 −V 2 )] from the median output potentials V 1 , V 2 of the MRE bridges A and B. The third differential amplifier A 3 therefore derives the single differential output Vd as:
[2×( V 3 − V 4 )−0.6×( V 1 − V 2 )]
[0127] By thus setting the amplification factor of the second differential amplifier A 2 a as 0.6, the amplitude of the compensation component is decreased, so that the waveform amplitude of the single differential output Vd is appropriately increased. Hence, the degree of latitude for rotation detection is made higher.
[0128] FIG. 16 shows results of electromagnetic simulation of the relationship between the degree of latitude and the amplification factor K 2 of the second differential circuit A 2 a , for the case of the wide-protrusion rotor 6 being the detection object. As shown by FIG. 16 , the smaller the value of the amplification factor K 2 is made, the higher becomes the degree of latitude. With this embodiment, the amplification factor K 2 is set as 0.6, which enables the degree of latitude to be made substantially higher than is achieved in the prior art (i.e., when the value of K 2 is set as 1).
[0129] FIG. 17 shows results of electromagnetic simulation of the relationship between the angular accuracy and the amplification factor K 2 of the second differential circuit A 2 a , for the case of various different configurations of rotor, i.e., for the case of the wide-protrusion rotor 6 and also the narrow-protrusion rotor 7 and the equal-pitch rotor 8 . As is clear from FIG. 17 , for each of these different rotor configurations, the angular accuracy exhibits a tendency to become lower as the amplification factor K 2 is reduced.
[0130] However as described above, when the wide-protrusion rotor 6 is utilized, coupled to the camshaft of an internal combustion engine for example, it is more important to achieve a high degree of latitude than to achieve a high level of angular accuracy. It is for that reason that the amplification factor K 2 of the differential circuit A 2 a of this embodiment is set as 0.6, so that a sufficiently high degree of latitude can be attained, although this is results in a lowering of the angular accuracy, to some extent.
[0131] FIGS. 18A to 18 C show relationships between the amplification factor K 2 of the differential circuit A 2 a , the main component and compensation component of the differential output Vd, and the differential output Vd, for the case of the wide-protrusion rotor 6 being the detection object. FIG. 18A shows the waveforms of Vd and the main component and compensation component of Vd, for the case of the amplification factor K 2 being 1.4. FIG. 18 B shows the waveforms of Vd and the main component and compensation component of Vd, for the case of the amplification factor K 2 being 1.0. FIG. 18C shows the waveforms of Vd and the main component and compensation component of Vd, for the case of the amplification factor K 2 being 0.6.
[0132] As is clear from these FIGS. 18A to 18 C, the lower the amplification factor K 2 of the differential circuit A 2 a is made (i.e., the differential circuit that produces the compensation component of the single differential output Vd), the greater becomes the amplitude of the waveform of Vd, where Vd is [K 2 ×(V 3 −V 4 )−K 1 ×(V 1 −V 2 )] as described above.
[0133] In addition, as is also clear from these FIGS. 18A to 18 C, as the amplification factor K 2 is successively reduced from 1.4 to 1.0 to 0.6, the degree of latitude accordingly changes from Wa′ to Wb′ to Wc′, where these have the relationship Wa′<Wb′<Wc′. Thus, the lower the value of the amplification factor K 2 of the second differential amplifier A 2 a , the higher becomes the degree of latitude of rotation detection.
[0134] As shown above, the following effects are obtained with this embodiment:
(1) Due to the fact that the amplification factor K 2 of the second differential amplifier A 2 a (which produces the compensation component of the differential output Vd) is set as 0.6, the amplitude of the compensation component (i.e., V 1 −V 2 ) is reduced, so that the amplitude of the differential output Vd is accordingly increased. In that way, the degree of latitude for detecting rotation information can be appropriately increased, to be suitable for the case in which the wide-protrusion rotor 6 is the detection object. (2) With this embodiment, the amplitude of the differential output Vd is adjusted electrically, by appropriately setting the amplification factor of a differential amplifier. Thus it is not necessary to alter the respective positions at which the MRE bridge A to D are set, so that it becomes possible to utilize a standardized component as the sensor chip, having a fixed array of MRE bridges. In that way, the same model of sensor chip can be applied in rotation detection for various different configurations of rotor, so that this embodiment has great generality of use.
[0137] With this embodiment, in the same way as for the first embodiment, the amplification factor K 1 of the first differential amplifier A 1 is set as 2. However it would be equally possible to set the value of K 2 higher than 2, in order to increase the amplitude of the main component of the differential output Vd. In that case, the increased amplitude of Vd will result in a higher degree of latitude being achieved.
[0138] Furthermore this embodiment, the amplification factor K 2 of the second differential amplifier A 2 is set as 0.6. However it would be equally possible to set K 2 at some other arbitrary value, that is less than 1.0.
[0139] Moreover although with the above embodiment, values of 2 and 0.6 respectively are set for the amplification factors K 1 , K 2 of the first and second differential amplifiers A 1 and A 2 a , it would be equally possible to utilize other arbitrarily determined values for K 1 and K 2 , so long as the following relationship is satisfied:
( K 1 ×( V 3 − V 4 )− K 2 ×( V 1 − V 2 ))>(2×( V 3 − V 4 )−( V 1 − V 2 ))
that is to say
( K 1 ×amplitude of main component)−( K 2 ×compensation component)>(2×amplitude of main component)−(amplitude of compensation component).
Fourth Embodiment
[0140] A fourth embodiment of a rotation detection apparatus according to the present invention will be described referring to FIGS. 19 and 20 . In the same way as for the second embodiment described above, this embodiment is suitable for detection of the rotation speed (rotation angle) of the crankshaft of an internal combustion engine, i.e., by detecting rotation information for a narrow-protrusion rotor 7 (shown in FIG. 7 , described hereinabove) that is coupled to the crankshaft. However with this embodiment as is clear from FIG. 19 , a differential circuit 5 b is used in place of the differential circuit 5 , and a sensor chip is used which is as described hereinabove referring to FIG. 15 .
[0141] The respective median output potentials of the MRE bridges A to D are inputted to the differential circuit 5 b as shown in FIG. 19 . The differential circuit 5 b basically consists of a first differential amplifier A 1 , a second differential amplifier A 2 b and a third differential amplifier A 3 . Of these, the second differential amplifier A 2 b which produces the compensation component has an amplification factor of 1.4, i.e., produces a differential output of 1.4×(V 1 −V 2 ) from the median output potentials V 1 , V 2 of the MRE bridges A and B. As a result, the third differential amplifier A 3 obtains the single differential output Vd as:
[2×( V 3 − V 4 )−1.4×( V 1 − V 2 )].
[0142] Rotation information for the narrow-protrusion rotor 7 is detected based upon this single differential output Vd.
[0143] In that way, by setting a value of 1.4 for the amplification factor of the second differential amplifier A 2 b which produces the compensation component of the differential output Vd, the amplitude of the compensation s component is increased, so that increased accuracy of edge detection is achieved of the peripheral protrusions of the narrow-protrusion rotor 7 , and hence enhanced angular accuracy is achieved.
[0144] FIG. 20 shows the results of electromagnetic simulation of the relationship between the amplification factor of the second differential amplifier A 2 b and the degree of latitude, for the case in which the narrow-protrusion rotor 7 is the detection object. As shown in FIG. 20 , the higher the value of the amplification factor K 2 , the higher becomes the degree of latitude. When K 2 is set as 1.4, a substantially higher degree of latitude can be achieved than for the prior art (i.e., when an amplification factor of 1 would be used for K 2 ).
[0145] As described above referring to FIG. 17 , when the narrow-protrusion rotor 7 is the detection object, the higher the value of the amplification factor K 2 of the second differential amplifier, the higher becomes the angular accuracy. Hence when a rotor such as the narrow-protrusion rotor 7 is the detection object, a high degree of angular accuracy can readily be achieved by setting the amplification factor K 2 of the second differential circuit A 2 b (which produces the compensation component of the differential output Vd) as 1.4.
[0146] As shown by the above, the following results are obtained with this embodiment:
(1) When a narrow-protrusion rotor is the detection object, a suitably high level of angular accuracy of rotation detection can be achieved by setting the amplification factor K 2 of the second differential amplifier A 2 b as a value substantially equal to 1.4. (2) With this embodiment, angular accuracy can be optimized by an electrical method, i.e., by appropriately setting the amplification factor of a differential amplifier. As a result, it is not necessary to alter the respective positions at which the MRE bridge A to D are set, in order to optimize the angular accuracy. This is an advantage, since there are limitations on the positions at which the MRE bridges can be located, to ensure that a sufficient value of saturation magnetic field is maintained. Furthermore the sensor chip can be formed as a standardized component, with the MRE bridges A to D fixedly arrayed in a row, for example. Hence, the same model of sensor chip 3 d can be applied in rotation detection for various different configurations of rotor, so that this embodiment can have high generality of application.
[0149] This embodiment has been described for the case in which the amplification factor of the second differential amplifier A 2 b is set as 1.4. However the invention is not limited to the use of such a value, and it would be possible to use some other appropriate value, so long as the following relationship is maintained between the differential amplifier factors K 1 and K 2 :
K 1 / K 2 <2.
[0150] Furthermore this embodiment has been described for the case in which the narrow-protrusion rotor 7 is the detection object. However it would be equally possible to apply the embodiment to rotation detection of a rotor such as the equal-pitch rotor 8 described above.
Other Embodiments
[0151] In addition to the above, other embodiments of the invention could be envisaged, e.g., as follows:
(a) With the embodiments described above, the distances L 1 to L 4 (e.g., as shown in FIG. 21 ) are made approximately equal. However this is not essential, and it would be possible for example to increase the distances L 3 and L 4 appropriately. (b) With the embodiments described above, the bias magnet 2 is formed with a cavity, to accommodate the sensor chip. However it would be equally possible to use various other configurations for the bias magnet 2 , for example to have a C-shape configuration as seen in cross-section. (c) With the embodiments described above, the sensor chip of each embodiment ( 3 a , 3 b , 3 c , 3 c ) is formed by molding of a synthetic resin. However it would be equally possible to mount the sensor chip directly upon the bias magnet 2 , without utilizing molding processing, (d) With the embodiments described above, four MRE bridges A to D are utilized, which are located symmetrically with respect to the central magnetic axis of the bias magnet. 2 . However it would be equally possible to use more then four MRE bridges, e.g., with an additional MRE bridge being located on the central magnetic axis of the bias magnet 2 . (e) With the embodiments described above, the amplification factor K 3 of the third differential amplifier A 3 is set as 1. However it would be equally possible to set a value for K 3 that is higher than 1. If that is done, then the amplitude of the differential output Vd can be increased (irrespective of the rotor configuration) so that the degree of latitude can be increased. (f) With the embodiments described above, increasing the degree of latitude or the angular accuracy is achieved by adjusting the positions of the MRE bridges A and B (for example, with the first and second embodiments), or by adjusting the amplification factor K 2 of the second differential amplifier (for example, with the first and second embodiments). However it would be equally possible to obtain a similar result by adjusting the positions of the MRE bridges A and B and also adjusting the amplification factors K 1 , K 2 , K 3 of the differential amplifiers A 1 , A 2 , A 3 appropriately. For example, if the positions of the MRE bridges A and B on the sensor chip should deviate from predetermined positions (i.e. due to manufacturing deviations) a required waveform shape for the single differential output signal Vd can be achieved by suitably adjusting the amplifier factor(s) of one or more of the differential amplifiers A 1 to A 3 . In that way it becomes possible to reduce the number of sensor chips that are rejected in the process of manufacture, i.e., the manufacturing yield of the sensor chips can be substantially increased.
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A rotation detection apparatus utilizes a bias magnet and an array of four or more sets of magnetoresistive elements, with each set producing an output potential varying according to changes of a magnetic field vector as protrusions and recessed portions of a rotor periphery move past the array, and utilizes differential amplifiers to operate on specific combinations of the output potentials for deriving a detection signal expressing rotation information. By appropriately adjusting respective positions of the sets of magnetoresistive elements and/or respective amplification factors of the differential amplifiers, suitable detection characteristics for various rotor configurations can be obtained.
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FIELD OF THE INVENTION
The invention relates to the attaching of a strip of cloth provided with a zip-fastener component to one of two trouser foreparts, a rim of the trouser forepart being folded over and the strip of cloth being joined to the trouser forepart at least in the area of the folded-over rim by means of a seam and to a sewing unit for performing this operation comprising a sewing machine and a guiding device with a workpiece holder movable relative to the sewing machine.
BACKGROUND OF THE INVENTION
It is known practice from the publication of Pfaff Industriemaschinen GmbH entitled "PFAFF 200-04 Special Service" to sew together the associated strip of cloth on a left trouser forepart, the so-called left fly lining, and the associated area of the trouser forepart. The sewn-on strip of cloth is then folded over and the associated zip-fastener half, i.e. the left zip-fastener component, is sewn on. This strip of cloth is subsequently folded over again and the left joining seam is produced between the strip of cloth and the trouser forepart. Also, the sewing of the right strip of cloth having the right zip-fastener component, i.e. the associated zip-fastener half, on to the right trouser forepart takes place in several work cycles.
It is known practice from U.S. patent specification No. 4,534,067 to manufacture trouser flies in such a manner that an additional strip of cloth is also cut in one piece with each of the two trouser foreparts in the fly area and is then folded over and sewn together with the trouser forepart. In addition, a zip-fastener half, i.e. a zip-fastener component, is also sewn on. In the case of the left trouser forepart the outer edge is pressed inwards so that a four-layered design is formed in this case which is then stitched.
In the co-pending patent application Ser. No. 07/336,210 "Method of attaching a strip of cloth with a zip-fastener component to a trouser forepart and sewing unit for putting the method into practice" a method has been created which enables a strip of cloth with a zip-fastener component to be attached to a trouser forepart with the minimum possible work. In accordance with this invention this problem is solved by a method of bringing, in each case, one trouser forepart and a strip of cloth provided with a zip-fastener component by way of folding into their final form and into their final position relative to one another and by then sewing them together in a single operation. Manipulations of cloth layers to be carried out between several sewing operations are thus already avoided.
SUMMARY OF THE INVENTION
It is an object of the invention to further develop the known method.
It is a further object of the invention to embody a sewing unit in such a way that it is especially suitable for the performance of the method.
In accordance with the invention the first problem is solved by the features that, prior to the strip of cloth being joined to the trouser forepart, first a rim of the strip of cloth and then the rim of the trouser forepart are folded over, with the strip of cloth being arranged above the trouser forepart and with the folded-over rim of the trouser forepart and the folded-over rim of the strip of cloth being positioned relative to one another in a position which they occupy after being joined together, that the folded-over rims are brought into mutual contact, and that the joining by means of a seam is effected in a single sewing operation. The method according to the invention makes it possible that the big workpiece, namely a trouser forepart, lies beneath and that the strip of cloth with the zip-fastener component is placed on to the trouser forepart from above. This results in a substantially simplified manipulation while, at the same time, in particular, the possibility of control by the operator and the transition to sewing are considerably simplified and improved. The method according to the invention assures in particular the folding over and sewing up of a corner of a strip of cloth, whereby clean manufacturing is achieved on the one hand and fraying of the strip of cloth in this area is avoided.
The basic design of an especially suitable sewing unit according to the invention is characterized by a folding device comprising all the individual component devices for the performance of diverse folding operations. Thus a particularly clear and simple design is achieved. All these component devices may be supplied or removed in a single uniform movement. Only a zip-fastener reception to receive a strip of cloth provided with a zip-fastener component is still provided as a separate movable unit.
A plurality of further advantages and features of the invention will become apparent from the ensuing description of an exemplary embodiment, taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a sewing unit;
FIG. 2 is a front view of the sewing unit corresponding to the arrow II in FIG. 1;
FIG. 3 is a cross-section through the sewing unit along the section line III--III in FIG. 2 which shows a partly broken-away side view of a preparatory station;
FIG. 4 is a plan view, on an enlarged scale, of a folding device in the direction of arrow IV in FIG. 3;
FIG. 5 is a cross-sectional view, in an enlarged view broken away several times, of the folding device along the section line V--V in FIG. 4;
FIG. 6 shows, on a clearly enlarged scale, a detail of FIG. 5;
FIG. 7 is a partial side view of the folding device in the direction of arrow VII in FIG. 4;
FIG. 8 is a partial plan view of the folding device showing a cloth-strip corner slider;
FIG. 9 is a partial side view of the cloth-strip corner slider in the direction of arrow IX in FIG. 8;
FIG. 10a and b are plan views of a cloth strip provided with a complete zip-fastener or of cloth strips continuously sewn together with a zip-fastener component;
FIG. 11 is a plan view of sewn-together trouser foreparts having a fly;
FIG. 12 shows a left trouser forepart in a finally sewn state; and
FIG. 13a to h shows the operational sequence of the folding of the rims of the cloth strip and the trouser forepart, and of the subsequent sewing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The sewing unit, which is shown in FIGS. 1 and 2 and which in this case is an automatic sewing unit, has a stand 1 on which a sewing machine 2 is rigidly arranged. It consists in the customary manner of a base plate 3, a standard 4 and an upper arm 5. Mounted in the arm 5 of the sewing machine in the customary manner is an arm shaft 6 which can be driven by an electric sewing machine drive motor 7. The drive of a needle bar 8 and a needle 9 and, in addition, the drive of a hook (not shown in the drawing) situated in the base plate 3 are derived in the customary manner from the arm shaft 6. A bearing plate 11 with an upper side defining a sewing plane 12 is arranged on the stand 1 above the upper side 10 of the latter. This bearing plate 11 is supported--at least partly--on a supporting plate 13 which is supported on the stand 1 by way of supports 14. This bearing plate 11 is also supported on the base plate 3 of the sewing machine 2 and, in the path of movement of the needle bar 8 and needle 9 defined as the z direction, has a stitch hole 15 which permits the passage of the needle 9 to the hook.
Above the bearing plate 11 there is provided a guiding device 16 for guiding workpieces which are to be sewn together and will be explained in even more detail further on. The device is--when seen from the operator's side 19--arranged behind the sewing machine 2. It has an upper base plate 20 which, in the rearward area 21 of the stand 1 opposite the operator's side 19, is supported--as seen from the operator's side--behind the bearing plate 11 on the stand 1 by way of vertical supporting walls 22. Attached to the underside of this base plate 20 are guide rods 23 which run parallel to one another in the x direction and on which a carriage 24 is mounted so as to be slidable in the x direction. This carriage 24 is driven by an electric motor 25 which in this case can be a geared motor, via a timing belt pulley 26 and an endless timing belt 27. The motor 25 and the timing belt pulley 26 are supported on the base plate 20. A deflection pulley 28 is likewise mounted in the base plate 20. The timing belt 27, which is arranged below the base plate 20 between the guide rods 23 and runs parallel to the latter, is connected to the carriage 24 by means of a securing device 29 which in this case is a clamping device.
Mounted on the underside of the carriage 24, designated as the x carriage, is a further pair of guide rods 30 which run in the y direction, i.e. perpendicular to the x direction, and parallel to one another and on which a further carriage 31 is slidably guided in the y direction. This carriage 31 is therefore designated as the y carriage. Both carriages 24, 31 are therefore guided suspended from respective guide rods 23 and 30. The y carriage 31 is driven by way of an electric motor 32--which, if necessary, is likewise in the form of a geared motor--and is attached to the x carriage 24 in the rearward area 21. It has a timing belt pulley 33 from which the y carriage 31 is driven via an endless timing belt 34. The timing belt 34 is guided parallel to the guide rods 30 via a deflection pulley 35 mounted on the underside of the y carriage 31, and is secured to the underside of the y carriage by means of a securing device 36. The x and y directions are perpendicular to one another and perpendicular to the z direction. The x, y and z directions therefore form a standard cartesian coordinate system. The x and y directions are parallel to the sewing plane 12. The x direction runs parallel to the main longitudinal direction of the sewing machine 2, i.e. parallel to the arm shaft 6.
A workpiece holder 37 is mounted on the underside of the y carriage 31 so as to be pivotable about a tilt axle 38 running parallel to the y direction. For this purpose the workpiece holder 37 is attached to the end of an angle lever 39, the other end of which is mounted on the tilt axle 38. As shown in FIGS. 1 and 2, the angle lever 39 is bent twice, that is, firstly, away from the workpiece holder 37 in the y direction towards the rear area 21 and, secondly, upwards in the z direction from the bearing plate 11 towards the underside of the y carriage 31. Between the tilt axle 38 and the workpiece holder 37 there is provided a lift and press drive 40 which, on the one hand, engages on the angle lever 39 and, on the other hand, on the y carriage 31. The drive in this case is a linear drive which is, customarily, in the form of a pneumatically operatable piston-cylinder drive. As is evident from the preceding text, the entire guiding device 16 is arranged together with all the associated components above the bearing plate 11, and can therefore be arranged very close to the sewing machine 2. The workpiece holder 37 has at least one slot 41 which follows the course of at least one seam to be produced, by means of which the two workpieces are to be sewn together.
The sewing machine 2 and the guiding device 16 are associated with a preparatory station 42 in which the workpieces are brought into the position relative to one another necessary for sewing. The preparatory station 42 has a folding device 43 in which a workpiece, which in this case is a trouser forepart, is brought together, when folded and correctly positioned, with the second workpiece which in this case is a strip of cloth with a zip-fastener component which is also previously folded. This folding device 43 has a cover-like carrier 44 which is arranged above the bearing plate 11 and projects partly above the latter towards the rear side 45 of the stand 1, the rear side 45 meaning the side opposite the operator's side 19. At its rear end the carrier 44 has a downwardly projecting lever arm 46. In the area where it passes into the lever arm 46, the carrier 44 is mounted so as to be pivotable about a tilt axle 47 which extends in the x direction and is supported in two bearing arms 48 which are mounted on the rear side 45 of the stand 1 and project from the stand towards the rear side 45 and in an upward direction. Engaging on the lower end of the lever arm 46 is a tilt drive 49 which in this case is a pneumatically operable four-position piston-cylinder drive, and which therefore, apart from two end positions, can be positioned in two intermediate positions, as a result of which the carrier 44 and thus a trouser part and zip-fastener folding device 50 supported by this carrier can be positioned in four different tilt positions. The tilt drive 49 is supported on the rear side 45 of the stand 1.
Two guide rods 51 parallel to one another, which extend perpendicularly to the x direction and on each of which the folding device 50 is slidably guided by means of a sliding bearing 52 are arranged in the carrier 44. When the carrier 44 is in the upward and rearward pivoted position shown in FIG. 3, the guide rods 51 extend in the y direction approximately parallel to the bearing plate 11. A displacing drive 53 for the folding device 50, which drive engages on the slide bearings 52, is arranged on the carrier 44 above and between the guide rods 51. This displacing drive 53 is therefore a linear drive which, in this case, can be for example a pneumatic cylinder without a piston rod, as is commercially available under the name ORIGA. By means of this displacing drive 53 the folding device 50 can be brought into a position fully extended out of the carrier 44 towards the operator's side 19--as shown on the left side in FIG. 3--and into a position fully retracted into the carrier 44--as shown on the right side in FIG. 3.
A zip-fastener receiving carrier 54, which is arranged essentially below the cover-like carrier 44 and particularly below the guide rods 51 with the sliding bearings 52, is likewise mounted pivotably on the tilt axle 47. At the rear end of this carrier 54 there is formed a downwardly extending arm 55 which is arranged essentially inside the lever arm 46. Engaging on the lower end of this arm 55 is a tilt drive 56 by means of which the zip-fastener receiving carrier 54 can be pivoted about the tilt axle 47. The tilt drive 56 is designed as a pneumatic three-position piston-cylinder drive, which can be positioned in positions corresponding to the three lower positions of the folding device 50. In the carrier 54 there are arranged--as can be seen in FIGS. 2 and 3--two guide rods 57 which are parallel to one another and extend essentially in the y direction and on which a reception 58 is mounted so as to be slidable by means of sliding bearings 59. The reception 58 is displaced by way of a reception displacing drive 60 which is arranged in the receiving carrier 54 and can be designed identically to the displacing drive 53. Displacement takes place between two end positions, of which the extended position is shown on the left in FIG. 3, whereas the retracted position is indicated on the right in FIG. 3 by a part of the sliding bearing 59 being represented by dot-dash lines.
The zip-fastener reception 58 has a bearing plate 61 which extends longitudinally essentially in the y direction and which is provided with a folding edge 62. A zip-fastener guiding rail 63 having a longitudinal slot in its bottom side facing the bearing plate 61 is arranged on the bearing plate 61 at a little distance only from the bearing plate 61. The guiding rail 63 provided as a U-profile or as a cut-open case profile serves to take up the toothed strip 65 of a zip-fastener component 67 sewn on a strip of cloth 66.
The folding device 50 has a bearing plate 68 on the bottom side of which a trouser sliding plate 69 is arranged, which is slidable in the x direction between two end positions by means of a sliding plate drive 70 arranged on the bearing plate 68. This drive 70 consists of a pneumatically operable two-position piston-cylinder drive, the cylinder 71 of which is supported on an abutment 72 arranged on the bearing plate 68, and the piston rod 73 of which is secured with its free end to a strip-shaped carriage 74. This carriage 74 is slidable on two parallel guiding rails 75 extending in the x direction, which are supported in the abutment 72, on the one hand, and in an end support 76, on the other hand. This carriage 74 projects cranked off through an opening 76a in the bearing plate 68 and bears the trouser sliding plate 69 below the bearing plate 68. The trouser sliding plate 69 is provided with a folding edge 77 running parallel to the folding edge 62 of the bearing plate 61 of the zip-fastener reception 58, which folding edge 77 is congruent with the folding edge 62 when the trouser sliding plate 69 is in an extended working position, as can be seen in particular in FIGS. 5 and 6. The cylinder 71 is connected to a source of compressed air not shown by way of compressed-air connections 78, 79.
Further, a cloth-strip side slider 80 is arranged on the bearing plate 68, by means of which slider 80 the rim 81 of the strip of cloth 66 sewn together with the zip-fastener component 67 is folded around the folding edge 62 of the bearing plate 61. This side slider 80 is about C-shaped, with its lower arm 82 sliding the rim 81 around the folding edge 62 (see FIGS. 5 and 6). The cloth-strip side slider 80 is connected with a pneumatically operatable displacing module 84 by means of a supporting bar 83. This pneumatically operatable displacing module 84 is movable between two end positions, in which the lower arm 82 of the cloth-strip side slider 80 either engages under the bearing plate 61--as shown in FIGS. 5 and 6--or in which both are free from one another, i.e. have been moved apart in the x direction.
Further, a trouser side slider 85 is provided at the bearing plate 68, which slider 85 is slidable between an inner and an outer end position equally by means of a displacing module 86. A supporting bar 87 extending further than the cloth-strip side slider 80 is secured to the displacing module 86. The trouser side slider 85 consisting of a flat and substantially rectangular plate is secured to the supporting bar 87 in a vertically slidable manner by means of two vertical guide rods 88. Pre-tensioned helical coil compression springs 89, which surround the guide rods 88 and by means of which power is exercised in downwards direction on the side slider 85, are provided between the supporting bar 87 and the side slider 85. The sliding path is limited by adjustable upper stops 90, which are secured to the guide rods 88 and which bear against the top side of the supporting bar 87.
A pressure drive 91 formed by a pneumatically operable piston-cylinder drive is arranged centrally between the two guide rods 88 at the supporting bar 87. The cylinder 92 of this drive is secured to the supporting bar 87 and its piston rod 93 can be moved out downwards towards the side slider 85, whereby, in the moved-out end position of the piston rod 93, the side slider 80 is fixed or blocked in its lower position relative to the supporting bar 87, in which position the stops 90 bear against the supporting bar 87. Alternatively the side slider 80 is fixed in a position in which it is downwards arrested. The pressure drive 91 cannot lift the bearing plate 68 upwards against the force of the tilt drive 49.
A cloth-strip corner slider 94 is provided below the bearing plate 68 and is slidable at an angle of about 45° relative to the x direction and the y direction, namely in cooperation with a cloth-strip corner folding edge 95 provided at the bearing plate 61. The corner slider 94, too, is slidable between two end positions by means of a displacing module 96 arranged on the bearing plate 68. In FIG. 8 the moved-out position is shown. It passes through an opening 94a in the bearing plate 68. In the position shown in FIGS. 8 and 9 the corner slider 94 has been moved under the folding edge 95, thus folding over a corner 97 of the strip of cloth 66--according to FIG. 9. All displacing modules 84, 86, 96 are pneumatically operatable and commercially available.
The bearing plate 68 has a recess 98 for receiving the zip-fastener guiding rail 63 so that the bearing plate 68 may also be lowered via the latter. On both sides of the recess 98 resilient bars 99, made for example of foamed rubber, are secured to the bottom side of the bearing plate 68, bear on the strip of cloth 66, which is held in the zip-fastener reception 58 and lies on the bearing plate 61, and press it on to the bearing plate 61.
Suction devices 100 are provided in the bearing plate 11 having suction openings 101 leading to the top side of the bearing plate 11. They are connected with a vacuum source not shown by means of one vacuum line 102 in each case. Thus sewing workpieces such as a trouser forepart 103, once positioned, can be held in this position on the bearing plate by means of underpressure.
A blowing device 104 is arranged adjacent to the folding edge 77 of the touser sliding plate 69, namely when the latter is in its moved-out working position, and is connected with the top side of the bearing plate 11 by way of blowing openings 105. It is connected with a source of compressed air not shown by means of a compressed-air pipe 106. The rim 107 of the trouser forepart 103 associated with the folding edge 77 can be lifted by means of this blowing device 104.
Prior to a detailed explanation of the mode of operation of the described sewing unit and of the method thus applied the basic problems of sewing technique are outlined with the help of FIG. 10 to 12. A left strip of cloth 66 is shown, on to which a left zip-fastener component 67 is sewn with a double seam 108. On the one hand, this can be realized in such a way that the left zip-fastener component 67 has already been connected with a right zip-fastener component 109, i.e. it has a stop 110 and a slider 111, as shown in FIG. 10a and FIG. 12. On the other hand, it is also possible to sew endless left zip-fastener components 67 on left cloth-strips 66 by means of the double seam 108 and to separate them before they are further processed, which still remains to be described. This is shown in FIG. 10b. The rim 112 of the cloth strip 66 which is not to be folded over, i.e. which is opposite the rim 81, has been provided with a finishing seam 113.
The left strip of cloth 66 with the left zip-fastener component 67 or the whole zip-fastener, respectively, also designated as fly lining or fly strip, is to be sewn into the left trouser forepart 103. The sewing in or sewing on, respectively, of the right zip-fastener component 109 with a right strip of cloth 114 to a right trouser forepart 115 is not described. After being sewn together the let trouser forepart 103 and the right trouser forepart 115 form a pair of foretrousers shown in FIG. 11 which, after connection with the two trouser hindparts not shown, makes a total pair of trousers.
The two trouser foreparts 103 and 115 are provided with pocket mouths 116, 116' and pocket pouches 117, 117'. Along their longitudinal edges the trouser foreparts 103, 115 are substantially finished by means of finishing seams 118, 118'.
In the following the sewing of a left strip of cloth 66 with a left zip-fastener component 67 to a left trouser forepart 103 is described and whenever the left strip of cloth 66 is mentioned, this means a left strip of cloth with an associated zip-fastener component 67.
In the start position of the preparatory station 42 the folding device 50 and the zip-fastener reception 58 are in their position facing away from the operator's side 19 towards the rear side 45.
First, the left trouser forepart 103 is put on the bearing plate 11, where it is aligned for example by means of marks on the bearing plate 11. The suction device 100 is put into operation so that the trouser forepart 103 is held where it has been positioned. Then the zip-fastener reception 58 is moved in its position towards the operator's side 19, namely in its upper position as shown in FIG. 3 in solid lines, by actuation of the displacing drive 60. The left strip of cloth 66 is introduced in the zip-fastener reception 58, so that it rests on the bearing plate 61, while the zip-fastener component 67 is pulled through the longitudinal slot 64 of the guiding rail 63. This position is shown in FIG. 13a.
Then the bearing plate is moved out in its upper position towards the operator's side 19 as shown in FIG. 3 top left. It is at a distance above the zip-fastener reception 58. Then the bearing plate is lowered into its middle position, i.e. into its upper intermediate position, by corresponding actuation of the tilt drive 49, as shown in FIG. 3 middle left. Thus the lower arm 82 of the cloth-strip side slider 80 takes a position below the bearing plate 61 folding the rim 81 of the strip of cloth 66 around the folding edge 62 as shown in FIG. 13b. Then compressed air is admitted to the displacing module 84 of the cloth-strip side slider 80 such that the lower arm 82 of the latter is drawn under the bearing plate, so that the rim 81 of the strip of cloth 66 is folded around the folding edge 62 of the bearing plate 61 a shown in FIG. 13c. At the same time the cloth-strip corner slider 94 is moved out by corresponding actuation of the displacing module 96, so that the corner 97 of the strip of cloth 66 is folded over around the cloth- strip corner folding edge 95 of the bearing plate 61.
Then the trouser sliding plate 69 is moved in the direction towards the trouser side slider 85 by corresponding actuation of the drive 70, so that the folding edge 77 of the trouser side slider 85 takes a position below the folding edge 62 of the bearing plate 61. Then the bearing plate 68 and the zip-fastener reception 58 are lowered to take in an intermediate position closely above the bearing plate 11 by corresponding actuation of the tilt drives 49, 56, as shown in FIG. 13a. Thus the trouser sliding plate 69 comes into contact with the trouser forepart 103 lying on the bearing plate 11. Further, compressed air is admitted to the pressure drive 91, so that the trouser side slider 85 is fixed in it slower position relative to the bearing plate 68. The compressed air is admitted to the blowing device 104, so that the rim 107 of the trouser forepart 103 is blown upwards, i.e. it is lifted, as shown in FIG. 13d.
Then the displacing module 86 of the trouser side slider 85 is actuated by compressed air in such a way that the rim 107 of the trouser forepart 103 is folded around the folding edge 77 of the trouser sliding plate 69. The flowing device 104 is switched off. By means of corresponding actuation of the tilt drives 49, 56 the bearing plate 68 and the zip-fastener reception 58 are brought into their lowest position. This position is shown in FIG. 13a. After lowering of the bearing plate 68 and the zip-fastener reception 58 the piston rod 93 of the pressure drive 91 is relieved, i.e. the trouser side slider 85 is no longer fixed.
The trouser side slider 85 now takes a position in which the stops 90 no longer bear on the supporting bar 87, as indicated in FIG. 5. They are lifted off the supporting bar 87 by about the dimension of the cloth thickness of the rim 107.
By means of a corresponding inverse actuation of the drive 70 the trouser sliding plate 69 is retracted. Further, the displacing module 86 is actuated in such a way that the trouser side slider 85 is again moved outwards. Then the displacing modules 84 and 96 are actuated in such a way that the cloth-strip side slider 80 and the cloth-strip corner slider 94, respectively, are again moved out of their folding-over position. Now all parts located at the bearing plate 68 are free of the trouser forepart and the strip of cloth 66. The bearing plate 68 can be tilted upwards into its uppermost position by a corresponding actuation of the tilt drive 49. The zip-fastener reception 58, however, still rests in its lower position, as can be taken from FIG. 13f. The workpiece holder 37, which might as well be designated as a transfer plate, is still in a sewing position 119 under the sewing machine 2. By moving the y carriage 31 and simultaneously actuating the lift and press drive 40 the workpiece holder 37 is moved in the direction towards the operator's side 19 and then lifted off, so that a finished workpiece, namely the trouser forepart 103, may be taken away. Then the workpiece holder 37 is moved towards the preparatory station 42 by moving the x carriage, i.e. over the folded trouser forepart 103 with the folded strip of cloth 66. By means of an inverse actuation of the lift and press drive 40 the workpiece holder is lowered on to the folded trouser forepart 103. The slot 41 of the workpiece holder is so dimensioned that it may take up the zip-fastener guiding rail 63 of the zip-fastener reception 58. A resilient pressure bar 120 projects into the slot 41 and bears against the strip of cloth 66 in the area between the folded-over rim 81 and the guiding rail 63.
Then the zip-fastener reception 58 is moved into its rear position, i.e. in the direction towards the rear side 45, by a corresponding actuation of the reception displacing drive. The trouser forepart 103 and the strip of cloth 66 with the zip-fastener component 67 now are only held between the workpiece holder 37 and the bearing plate 11. By a corresponding moving of the x carriage 24 and of the y carriage 31 the trouser forepart 103 and the strip of cloth 66 are moved out of the transfer position into the sewing position 119 under the sewing machine 2.
There, proceeding from a seam starting point N in an upper outer corner N, the strip of cloth 66 and the trouser forepart 103 are sewn together along the folded-over rims 81, 107 in a straight-line seam 122 to a lower outer seam point O. From there the area of the rim 112 of the strip of cloth 66 is sewn by means of a J-shaped seam 123 to an upper inner seam point P, with the corner 97 of the strip of cloth 66 and the trouser forepart 103 being sewn in. Then a short seam 124 is sewn in the direction towards the seam starting point N to a point Q and from there a J-seam 125 parallel to the J-seam 123 is sewn to a seam end point R of the seam 122. Then the section from R to Q is sewn once again.
As can be taken from the above-outlined, the sewing of the trouser forepart 103 is done from behind, i.e. the sight seam lying outwards according to FIG. 11 is formed by the looper thread of the sewing machine 2, while the seam lying inwards in FIG. 12 is formed by the needle thread.
The sewing of the described seams may still be followed by the sewing of further seams on the trouser forepart 103--if the workpiece is designed to this effect. For example, the pocket pouch 117 may be secured by a seam block 126.
In order to avoid slipping of the trouser forepart 103 and the strip of cloth 66 with the zip-fastener component 67 positioned on the forepart 103 during movement by means of the guiding device 16 on the bearing plate 11 relative to the workpiece holder 37 serving as a transfer plate, the latter is provided in usual manner with adhesion means such as foamed rubber strips or the like on its side facing the trouser forepart 103.
For the purpose of automatization of the work cycles described, a computer 127 is provided, by means of which the various drives are triggered in sequence after an initial triggering by the operator.
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For the purpose of attaching a strip of cloth provided with a zip-fastener component to a trouser forepart, first a rim of the strip of cloth and then the rim of the trouser forepart are folded over. The strip of cloth is arranged above the trouser forepart. Both folded-over rims are brought into a position relative to each other which they occupy after being joined together. Then they are brought into mutual contact and joined together with only a single seam in only one sewing operation. Thus very simple handling of the parts to be sewn together is achieved along with a very simple design of the required sewing units.
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The invention herein described was made in the course of or under a contract or subcontract thereunder (or grant) with the Department of the Navy.
BACKGROUND OF THE INVENTION
This invention relates to gas turbine engines and, more particularly, to thrust vectorable nozzles for use therein.
The high velocity imparted to the exhaust gases of a gas turbine engine by the exhaust nozzle provides the thrust for propulsion. This thrust is substantially parallel with, and opposite to the direction of, exhaust gases exiting the nozzle. Consequently, if the direction of the exhaust gases is changed, the direction of propulsive thrust is correspondingly varied. Typically, aircraft gas turbine engines are provided with nozzles which are fixed in the axial direction, and aircraft maneuvering is accomplished solely by airframe control surfaces.
Advanced aircraft configurations contemplate, and may even require, the selective redirection (or vectoring) of gas turbine engine thrust in order to enhance aircraft performance and to provide the aircraft with operational characteristics heretofore deemed impractical. For example, if the exhaust of a conventionally installed gas turbine engine was directed downward, rather than rearward, to a direction substantially perpendicular to the engine longitudinal axis, the resulting upward thrust would provide direct lift for the aircraft and, therefore, a vertical take-off and landing capability. Similarly, thrust vectoring during flight can greatly increase aircraft maneuverability since the thrust force can augment the manuevering forces of the aircraft control surfaces such as elevators, ailerons and rudders. In order to accomplish such thrust vectoring, a device is required to efficiently and practically alter the direction of gas turbine engine exhaust nozzle gases.
The concept of thrust vectoring by itself is not new since exhaust nozzles with this capability have been considered for years, and a wide variety of thrust vectorable nozzles have evolved. However, these nozzles have typically included one or more of the following limitations:
Discontinuous vectoring between the cruise mode and the lift mode;
Air frame doors required to accommodate exhaust deflectors in at least one operational mode;
low lift thrust available when compared to the required weight addition of the basic cruise engine;
excessive complexity;
excessive downward projection in the lift mode resulting in ground clearance problems; and
slow vector angle and nozzle area rate of variation.
The problem facing the gas turbine engine designer, therefore, is to provide a flight maneuverable exhaust nozzle which avoids all of the above limitations.
SUMMARY OF THE INVENTION
Accordingly, it is the primary object of the present invention to provide an exhaust nozzle having highly efficient turning and which will provide continuous thrust vectoring between vertical take-off(lift), in-flight maneuvering and conventional cruise modes.
It is further object of this invention to provide a thrust vectorable nozzle of reduced complexity and possessing an aerodynamically efficient envelope.
It is yet another object of this invention to provide an improved method of operating a thrust vectorable nozzle.
These and other objects and advantages will be more clearly understood from the following detailed description, drawings and specific examples, all of which are intended to be typical of rather than in any way limiting to the scope of the present invention.
Briefly stated, the above objectives are accomplished by means of an exhaust device which, in one form, consists of a two-dimensional (substantially rectangular), external expansion-type cruise nozzle with internal area variation provided by cooperating convergent-divergent variable flaps. A flap, conveniently a wing flap, located downstream of the convergent-divergent flaps provided flight maneuver vectoring as well as exhaust flow expansion control. A variable area ventral flap located downstream of and opposite to the convergent and divergent flaps provides nozzle throat area control in the lift mode and provides additional expansion area control in the cruise mode.
For vertical take-off and landing or short take-off and landing operation (V/STOL), a rotating bonnet-type deflector is used to deflect the exhaust stream downward. This deflector is stowed externally to the smooth internal flow path during cruise operation so as not to compromise performance and to simplify cooling during afterburning (or "augmented") operation. The nozzle throat is adapted to rotate with the deflector to produce efficient turning of the exhaust stream.
DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as part of the present invention, it is believed that the invention will be more fully understood from the following description of the preferred embodiments which is given by way of example with the accompanying drawings, in which:
FIG. 1 diagrammatically depicts a wing-mounted gas turbine engine incorporating the present invention;
FIG. 2 depicts schematically the exhaust device of the present invention in several operating modes;
FIG. 3 is an isometric view of the wing-mounted exhaust device in an operating mode of FIG. 2;
FIG. 4 is a schematic representation, similar to FIG. 2, and depicting the present invention in a vertical take-off mode; and
FIG. 5 is an isometric view, similar to FIG. 3, of the exhaust device of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings wherein like numerals correspond to like elements throughout, attention is first directed to FIG. 1 wherein a gas turbine engine, depicted generally at 10, and embodying the present invention is diagrammatically shown. Hot gases of combustion are expanded through a turbine (not shown) in a manner well known in the art and enters exhaust device 12 from the left as depicted by vector 14. (As used hereinafter, the term "exhaust device" is meant to include a fan duct exhaust nozzle, or any other gas turbine engine exhaust nozzle whether or not it is preceded in serial flow relationship by a combustor. In the embodiment of FIG. 1 the gas turbine engine has been augmented by an afterburner 16 of a variety known in the art.) After passing through exhaust device 12, the flow is vectored from the device in a manner to be described.
Referring now to FIGS. 2 and 4 wherein the exhaust device of FIG. 1 is shown schematically in greater detail, it is apparent that the exhaust device is of the two-dimensional variety, in this embodiment, having a substantially rectangular cross section. While the present invention is not meant to be limited to devices of rectangular cross section, as it will become apparent that the invention may be applied to devices having a moderately arcuate cross section, it has been found that a substantially rectangular cross section provides a preferred embodiment for the subject invention. This has the added advantage of permitting the exhaust device to be conformably nested with an aircraft wing 18 as depicted in FIGS. 3 and 5. Since the turbine area of a gas turbine engine is of generally circular cross section, a transition duct section 20 is required between the turbine and exhaust device 12.
The exhaust device is shown to include two substantially opposed walls 22, 24, the wall 22 including a liner 26 in the present embodiment. The inner surfaces 28 of wall 24 and inner surface of wall 22 represented by liner 26 partially define an exhaust stream flow path 30. Wall 22 is further defined by convergent-divergent means comprising cooperating nozzle flaps 32, 34, each hinged at one end, 36, 38, respectively, to wall 22. The other ends are connected, as by roller and cam arrangement, at 40. The exhaust stream flow path 30 area is thus controlled, in part, by the positioning of the nozzle flaps, such as through state-of-the-art actuator means 42.
The variable flap 44 located downstream of the nozzle flaps provides flight manuever vectoring as well as exhaust stream expansion control. As shown, flap 44 comprises a portion of the trailing edge of wing 18, the wing comprising part of the aircraft structure. However, in other embodiments, the flap may be engine- or fuselage-mounted. A variable area ventral flap 46 which forms the downstream extremity of wall 24, cooperates with nozzle flaps 32 and 34 to control the area of exhaust stream flow path 30 and provides exhaust stream expansion control. Further, as will be discussed hereinafter, ventral flap 46 provides nozzle throat area control in the vertical rake-off and landing, and short take-off and landing (V/STOL) modes. Flaps 44 and 46 may be maneuvered by known actuating means 48 and 50, respectively.
For V/STOL operation, a rotating bonnet-type deflector 52 is used to deflect the exhaust stream downward. Deflector 52 possesses a substantially U-shaped cross-sectional profile, as most clearly depicted in FIG. 5, and consists of an arcuate deflector portion 54 flanked by two pie-shaped arm members 56, 58. During cruise operation, the deflector 52 is stowed within wall 22 so that it does not compromise the aerodynamically smooth contours of flow path 30. Thus, it does not affect high cruise nozzle efficiency and simplifies nozzle cooling during augmented (afterburning) operation. In the V/STOL mode, the deflector 52 is rotated about its pivot connections (only one of which is shown at 60) by means of actuator 62 into flow path 30, thereby deflecting the exhaust stream in a downward direction.
In operation, during the flight cruise mode, and wherein for present consideration the afterburner 16 is not in operation, nozzle flaps 32, 34 would be positioned substantially as depicted by solid lines in FIG. 2 such as to cooperate with opposite wall 24 to form a nozzle throat therebetween. Exhaust gas expansion control is obtained on one side by means of divergent nozzle flap 34 and wing flap 44 in cooperating relationship, while ventral flap 46 provides expansion control on the other wall. The remaining sides or lateral wall portions 64, 66 of exhaust device 12 (FIGS. 3 and 5) are of fixed geometry and therefore do not directly contribute to the variability of exhaust stream flow path 30.
Thus, in the flight cruise mode, nozzle area control is provided by varying the nozzle flaps 32, 34, while wing flap 44 and ventral flap 46 must be varied with nozzle pressure ratio to provide efficient expansion of the exhaust flow. For example, in an augmented cruise mode, the nozzle flaps would assume a position substantially similar to that as shown in phantom at 32' and 34' in FIG. 2, while the ventral flap would be opened up as at 46' shown in phantom. It is apparent that in the cruise mode of operation the throat 68 (minimum flow area) is located upstream of flaps 44 and 46, and the direction of thrust is substantially parallel with and opposite in direction to, vector 14.
In-flight thrust vectoring during the cruise mode, whether augmented or unaugmented, is accomplished through variation of the wing flap 44 which causes deflection of the exhaust stream. As flap 44 is rotated downward to the position shown in phantom at 44' in FIG. 2, the exhaust stream impinging thereupon is deflected downward, thus providing an upward component to the thrust vector which supplements aircraft lift created by the conventional control surfaces. This, in turn, greatly enhances aircraft maneuverability. Furthermore, vectoring is accomplished smoothly and continuously, and is independent of engine power setting since the input to actuator 48 is anticipated to be related to the aircraft conventional control surface actuators rather than the engine throttle control.
In the lift mode of operation, the deflector 52 is rotated from its stowed position within wall 24 to a deployed position as indicated in FIGS. 4 and 5. As the exhaust stream impinges upon the arcuate deflector portion 54, the stream is deflected downward approximately perpendicular to the incoming exhaust stream vector 14 thereby providing a substantial upward lifting force. Such lift could be used to provide a vertical take-off capability or, combined with an aircraft forward velocity component, an extremely short take-off roll.
In one form of the present invention, the rotating deflector 52 is operated in conjunction with ventral flap 46 to rotate the plane of the exhaust throat as the deflector 52 is deployed. In particular, the throat is rotated such that the exhaust stream is turned upstream of the throat at velocities substantially lower than sonic so that serious pressure loss in the turn is avoided.
In the cruise mode of FIG. 2, the throat 68 is forward of the ventral flap 46 so that the throat area is independent of the ventral flap position. The ventral flap is then positioned to control supersonic expansion. In the lift mode of FIG. 4, the throat 70 is established by the downstream tip of the ventral flap 46 and the deflector position. Actuators 50 and 62 are synchronized such that the throat rotates with the deflector, one means of synchronization comprising the subject of copending patent application Ser. No. 572,341, assigned to the same assignee as the present invention.
In order to provide a large flow area upstream of the throat for low velocities and efficient flow turning, the nozzle flaps 32, 34 are positioned in an extreme upward position as shown in FIG. 4. Once the deflector 52 is deployed to the lift mode, exhaust stream flow path area is fixed and thrust is modulated by simultaneous variation of engine speed and augmenter fuel flow. This method of thrust modulation produces rapid thrust response for effective control.
Since, in its deployed position, the deflector 52 is disposed aft of the downstream extremity of wall 24 thereby causing the exhaust flow to turn around ventral flap 46, the need for secondary exhaust ports has been eliminated. In prior designs these ports were opened in the lift mode to provide a downward-facing opening for the exhaust stream, and closed by means of complicated door and louver arrangements in the cruise mode. Note that in the deployed position of FIG. 4, the downward projection of the deflector 52 does not substantially reduce vertical ground clearance of the gas turbine engine.
Continuous vectoring between the lift and cruise modes is provided by the present invention since, as the deflector 52 is rotated to its stowed position, the thrust vector is correspondingly rotated to the conventional cruise mode. The wing flap may be programmed to assist in this transition as the deflector nears its stowed position. The rate of vector angle rotation is limited only by the speed of the actuator. The elimination of airframe doors and partial integration into the aircraft structure provides for a lightweight design. That, combined with efficient turning, results in a high thrust-to-weight ratio in the lift mode.
It will be obvious to one skilled in the art that certain changes can be made to the above-described invention without departing from the broad inventive concepts thereof. For example, the invention could be utilized to direct exhaust flow other than downward and may be installed in an aircraft pylon or fuselage. Further, a plurality of telescoping deflector segments could replace the single bonnet-type depicted. It is intended that the appended claims cover these and all over variations in the present invention's broader inventive concepts.
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A flight maneuverable gas turbine exhaust nozzle is provided with cooperating variable internal converging-diverging flaps to provide area control. A flap downstream of the converging-diverging flap provides flight maneuver vectoring as well as external exhaust expansion control. A vertical take-off and landing capability is provided by deployment of a rotating bonnet-type deflector which diverts the exhaust stream downward around one side of the exhaust nozzle. The nozzle throat rotates with the deflector to produce efficient turning of the exhaust stream.
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BACKGROUND
The present invention relates to fire extinguishing apparatus and more particularly to a system for extinguishing fires consuming combustible liquids or gases issuing from conduits such as pipes, gas wells, and the like.
The danger of accidental combustion of combustible liquids and gases has been recognized for many years. These fires have occurred with some frequency ever since the first oil and natural gas wells were drilled. The problem has become particularly acute with the advent of drilling techniques which allowed deeper wells which tapped combustible fluids under greater pressure.
After careful consideration of the above-noted problems and prior art solutions, the inventor herein has invented a new and improved fire extinguishing system that may be lifted and disposed over a flaming well, for example, which system includes an elongated tubular structure or body having a relatively wide lower opening to accommodate a wide variety of fire intensities, a unique valve arrangement at its uppermost extremity, and a fire retardant material exhausting structure adjacent its lower extremity. Intermediate the ends of the tubular body is a gradually reduced diameter section which causes a vacuum state at the bottom of the elongated body in order to pull the fire retardant material into the elongated cylinder and thereby prevent combustion from occurring or continuing within the cylinder. The invention is first configured to allow the full force of the flaming gushing fluids to flow through the structure before commencing the flooding of the lower area adjacent the ground with fire retardant material to prevent oxygen from supporting any combustion of the emanating combustible fluid. The valve mechanism is then gradually closed to divert the fluid back through the tubular body which acts as a pressure muffler at this point. The prior art has been investigated to determine the techniques that have been developed to overcome the above noted problems, prior to the present invention. For example, in U.S Pat. No. 1,520,288 a device is disclosed for extinguishing fires in oil wells that is adapted to fit over the mouth of a well and carries chemicals for extinguishing the flames with means for forcing the chemicals from it after it is put in place. The device includes a cone-shaped body which is formed of boiler plate or the like, with inner and outer walls forming a chamber, and has an upper outlet pipe to allow some of the pressure created by the burning oil or gas to escape while the same is being put in position and thus facilitate the placing of the device over the well. The inner wall of the body has a plurality of openings which are closed by plugs of soft material so that when steam, air, or water is forced into the chamber between the double walls, the soft plugs will be expelled and the chemicals driven from the chamber against the flames to extinguish the same.
U.S. Pat. No. 1,807,498 shows a well capping device adapted for use in capping gushing oil or gas wells. The device includes a bell-shaped cap having an outlet pipe, cement or other adhesive material inlet pipes, and an inner chamber defining lip structure. The cap is placed over a well casing and the area is sealed with cement or the like through a feed line pipe, while the force of the well is allowed to vent through the discharge pipe. A valve is provided at the top of the discharge pipe so that when any fire exciting from an upper fire pipe extending upwardly from the valve is extinguished by the closing of this fire pipe valve, valves in two horizontal lead-off pipes may be opened to provide paths for the oil to flow to storage facilities.
U.S. Pat. No. 2,082,216 discloses a fire extinguishing apparatus that basically consists of a pipe having a control valve, an upper outlet end, and a lower end that is shaped to telescope with the upper end of a well pipe. The pipe is swung over the well while the well is burning and is then lowered into telescopic relation with the upper end of the pipe. In order to protect the workmen from intense heat, a shield is secured around the pipe. Also, a pipe clamp is provided in order to secure the pipe onto the well pipe. The shield is positioned at an angle to deflect flames away from workmen, who can close the valve once the joint at the clamp is cemented securely by the flow of such material into the joint by opening a supply valve leading to an inlet pipe.
U.S. Pat. No. 2,096,970 involves a means and method for extinguishing oil well fires, and includes an elongated conduit capable of conducting water under pressure, a lower end for fitting on top of a well pipe, a water feed pipe with joints for providing the water to the interior of the conduit or pipe, an upper hole, and a slot in the upper portion of the pipe fitted with a pulley for lowering a conventional explosive torpedo toward the bottom of the pipe for exploding when it is in a proper position.
U.S. Pat. No. 3,887,011 shows a fire extinguisher for extinguishing an oil well fire that has a first pipe connectable to a well pipe and a second pipe branched from the first pipe in saguaro-like fashion. The first pipe is provided with a normally open first valve and a second flap-valve, while a normally-closed third valve is provided in the second pipe. The valves are coupled together by a linkage arrangement to provide a particular operation. Also, hooks are fabricated from meltable material such as lead which melt when heated sufficiently to produce certain unattended functions designed to extinguish a fire. In order to extinguish a fire, this apparatus first closes off the upper valve where the flame exists, at which time the fluid in the apparatus is diverted by the valving to the horizontal pipe leading to a storage tank, for example.
U.S. Pat. No. 4,194,570 covers a flow momentum reversing fire abatement system for extinguishing fires in well, pipes, or vent stacks. The apparatus comprises an extinguisher body having an inlet end and an outlet end that has a cylindrical passageway or bore from the inlet to the outlet ends. The inlet and outlet ends are adapted to be coupled in a fluid tight connection with the opposing ends of a combustible fluid pipe. A diffuser cone is disposed within the extinguisher body bore in coaxial alignment with the apex towards the outlet end of the extinguisher body. An extinguisher fluid nozzle is mounted within the body bore pointed at the top of the diffuser cone. Carbon dioxide, nitrogen, or helium may be used as an extinguishing fluid flowing through the nozzle.
U.S. Pat. No. 4,337,831 is a fire extinguishing apparatus for oil wells that has a plurality of containers that contain fire extinguishing material under pressure and that are connected to a main fire extinguishing container. The main container has a conduit leading from a valve in the neck thereof to the interior of a bell nipple positioned on an oil well blow out preventor. The valve has a vertically reciprocatable plunger therein, which when actuated downwardly permits free flow of the fire extinguishing material contained in the several containers to flow through a valve outlet leading to the bell nipple.
U.S. Pat. No. 4,433,733 shows an oil storage tank extinguisher or snuffer for putting out fires in oil tanks or oil wells which consists of a framework made from vertical members which are joined together at the bottom by a circular frame member and at the top by a similar frame member. The frame is designed to withstand fire for a sufficient period of time to extinguish the fire and is covered by a flexible material such as asbestos having cylindrical side walls and a top. A fire retardant fluid may be injected within the snuffer if desired by means of nozzles, for example. If there is an excessive build up of liquid within the chamber, it can be drawn off through a line.
And U.S. Pat. No. 4,899,827 discloses an oil well fire control system by injecting pressurized carbon dioxide, nitrogen, or monoammonia phosphate, into the flow of hydrocarbons from the drill pipe and casing through a spool apparatus located above the casing. Untreated water may be used as a back-up fluid after the chemicals have been dissipated.
From the foregoing it should be clear that none of the prior art techniques provide the adjustable valve/fire retardant flooding combination technique of the invention. Thus, it should be recognized that a fire extinguishing apparatus that is relatively easily positioned over even a very high pressure gushing and flaming oil well and the like before applying a combination of its features that quickly extinguishes all flames that exist at the well site and prevents re-ignition, constitutes an important advancement in the art.
SUMMARY OF THE INVENTION
In view of the foregoing factors and conditions characteristic of the prior art, it is a primary objective of the present invention to provide a new and improved fire extinguishing system that is particularly advantageously applied to the problem of extinguishing oil and gas well fires emanating from high pressure wells.
In accordance with an embodiment of the present invention, an extinguishing system for extinguishing flames from combustible fluids exiting from a pipe such as an oil or gas well casing includes an elongated tubular extinguisher body disposable over a combustible fluid emitting pipe, the extinguisher body having a lower inlet end and an upper outlet end and is adapted to accommodate the entire flow of combustible fluid through the extinguisher body. The invention also includes valve means mounted in the extinguisher body adjacent the upper outlet end for eliminating the flow of the combustible fluid through the extinguisher body. Further, the invention includes flame inhibiting means including circular nozzle structures disposed adjacent the lower inlet end and adjacent the valve means, externally of the extinguisher body, for preventing the support of combustion around and below the extinguisher body's lower inlet end and around and adjacent the valve means.
According to a presently preferred embodiment of the invention, the valve means includes a conical valve member and an associated annular valve seat disposed within the tubular body adjacent the top thereof. Alternately, a flapper valve configuration may be utilized where combustible fluid pressure flowing through the tubular body is not extremely high.
Thus, the present invention provides a new approach to contain and extinguish oil and gas well fires that is easily movable to a flaming oil well fire site and disposable thereon to extinguish the flame.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference characters relate to like elements, and in which:
FIG. 1 is a perspective view of an extinguishing system for extinguishing flames from combustible fluids exiting from a vertical pipe, in accordance with the present invention;
FIG. 2 is an elevational view, partially in section, of the oil well fire extinguishing system of FIG. 1;
FIG. 3 is an enlarged view, partially broken away, of the upper cross section of the oil well fire extinguishing system shown in FIG. 2;
FIG. 4 is a bottom plan view of the oil well fire extinguishing system's lower fire retardant dispersing rings of FIG. 1;
FIG. 5 is a perspective top view of the upper fire retardant dispersing ring shown in FIG. 4;
FIG. 6 is an enlarged view of a portion of the ring of FIG. 4;
FIG. 7 is a cross sectional view of the portion of the ring taken along the line 7--7 shown in FIG. 6;
FIG. 8 is an enlarged view of valve arrangement constructed in accordance with another embodiment of the present invention;
FIG. 9 is a bottom plan view of the valve plug member of FIG. 3;
FIG. 9a is a perspective view of the valve plug member of FIG. 3;
FIG. 10 is a bottom plan view of the valve plug member of FIG. 8; and
FIG. 10a is a perspective view of the valve plug member of FIG. 8.
DETAILED DESCRIPTION
Referring now to the drawings and more particularly to FIGS. 1 through 3, there is shown an oil well fire extinguishing system 11 for extinguishing a flaming combustible fluid 12 and having an elongated tubular extinguisher body 13 of steel, for example. In accordance with this embodiment, the body 13 has three distinctive section, namely, a lower, relatively larger diameter section 15, an intermediate transitional gradually tapered section 17, and an upper relatively smaller diameter section 19. As can be seen in FIGS. 1 and 2, the upper end of the intermediate tubular section 17 adjacent the upper section 19 has a diameter that is less than the opposite or lower end thereof adjacent the lower section 15. Although the upper section 19 and the lower section 15 are shown as single sections of tubing, it should be understood that additional lengths of tubing may be coupled by conventional connection means such as flanges, for example, to extend the overall length of each such section.
The adjoining sections 15, 17, and 19 may be joined by conventional circular flanges 21 utilizing conventional nut/bolt, rivet, or welding techniques. Also, in order to stabilize the tubular body 13 in a vertical orientation, once positioned in place of an oil or gas well head 22, by a crane or the like through the use of a conventional steel cable arrangement 23, steel guy cables 25 are deployed and anchored in the surrounding ground, for example, by the use of guy anchor eyes 27.
As can best be seen in FIGS. 2 and 3, the lifting cables 23 are attachable by any conventional means such as shackles, crimped sleeves, U-bolts, and the like, to holes 29 in a pair of vertical solid bars 31 extending a short distance above, and a relatively much longer distance below, a horizontal steel upper plate 33. The attachment between the bars 31 and the circular plate 33 may be made by any conventional means such as welding, for example.
An upper outlet end 34 of the upper tube 19 is an outwardly extending circular lip 35, and welded or otherwise attached at opposite sides of the tube 19 below the lip 35 are vertically aligned pairs of outwardly extending brackets 37 that are each welded, for example, to outwardly extending U-shaped channel members 39. The open end of each channel member 39 is closed along its length by an inner plate member 41 by welding, for example, and outer plates 43 that are welded to each side of associated vertical bar members 31 may be attached by bolts 45 to associated ones of the inner plate members 41. Thus, the upper circular plate 33 and its depending bar members 31 are fixedly attached to the upper portion of the upper tube 19, and the lifting force provided by the cables 23 will extend to and lift the entire tubular body 13.
Disposed above and extendable within the upper end of the upper tube 19 is a complex conical sectioned, valve plug member 47, in this embodiment having an upper circular vertical side portion 49, an intermediate beveled conical section 51, and a lower downwardly-pointing cone portion 53. The plug member 47 may be fabricated in one piece by machining or a casting process, or it may be fabricated in two or three separate sections that are joined permanently together by well known conventional techniques.
Attached by bolts 55, for example, is a plate 57 welded or otherwise attached to a vertically oriented valve bar 59 that is provided with a conventional rack configured side 61 that engages a conventionally designed pinion mechanism 63 mounted on the circular plate 33. The bar 59 extends through a centrally disposed hole 65 in the plate 33, and is capable of lowering and raising the valve plug 47 even under extremely high hydraulic pressure from the combustible fluid 12 such as oil, for example, flowing upwardly from a well head through the tubular body 13.
The pinion mechanism 63 includes a vertical bracket member 67 rotatably supporting an axle 69 to which ends are respectively attached a vertical pinion gear 71 and a pulley wheel 73 that is rotated by linear movement of a conventional steel valve cable 75. The vertically oriented pinion gear 71 engages a horizontally oriented pinion gear 77 that is rotatably mounted on a vertical pin 79 permanently attached to the upper side of the horizontal plate 33. In order to assure constant engagement between the rack and pinion members of the valve plug moving arrangement, a wheel assembly 81 is fixedly mounted on the plate 33 on the side of and in constant rolling engagement with the bar 59 opposite the horizontal pinion gear 77.
In order to stabilize and keep the valve plug member 47 in constant axial alignment with the centerline of the elongated tubular body 13 while moving from its upper "open" position 83 (depicted by dashed outlines) to its lower "closed" position 85, a pair of oppositely disposed, vertically oriented, elongated valve guide arms 87 are fixedly attached by means of horizontally extending short arm sections 89 to opposite sides of the upper section 49 of the valve plug 47. The valve guide arms 87 are aligned with and vertically movable within associated ones of the U-shaped channel members 39.
In its "closed" position 85, the intermediate section 51 of the conical valve plug member 47 sealably engages an appropriately beveled inner valve seat surface 91 of an annular valve seat member 93 that is mounted on top of the lip section 35 of the tube section 19 and held in place by conventional means such as bolts 95, for example. The valve plug and seat members should be fabricated from well known conventional materials such as metals that can withstand the high temperatures that will be experienced from a well fire.
As best seen in FIGS. 1 through 5, the invention also includes a flame inhibiting arrangement basically consisting of a lower ring flame retardant-dispersing assembly 97, and an upper ring flame retardant-dispersing assembly 99.
The lower ring assembly 97, see also FIGS. 4 and 5, consists of three coaxially aligned circular nozzle structure or rings 101, 103, and 105, disposed in spaced parallel planes adjacent to a lower inlet end 107 of the lower tubular body section 15. Each ring is fed by associated feed pipes 109, 111, and 113, which may be supported in a horizontal orientation by a steel cable 115 anchored to one of the anchor eyes 27.
This arrangement may be best implemented by the use of a horizontally extending arm 117 movably attached at its inner end 119 by a pivot pin arrangement 121 to the side of the lower tube section 15, and to the support cable 115 by means of an eye 123 at the outer end of the arm 117. A conventional metal strap arrangement 125 may be used to hold all three feed pipes 109, 111 and 113,
Each ring assembly is supported in a different horizontal plane by four sets of radially extending arms 127 each anchored by a band assembly 129 attached to the outer surface of the lower tubular member 15 by any conventional means such as, for example, four curved strips 131 clamped together at their outwardly extending tab ends 133 by bolt assemblies 135 (FIG 5). The upper ring assembly 101 also preferably supports a metal sheet (or assembly of connected metal sheets) 137 that acts as a cover or hat or lid. For the sake of clarity, the arms 127 and the sheet 137 is not shown in place in FIG. 1.
In accordance with the first embodiment of the present invention, the upper ring assembly 99 consists of a vertical feed pipe 139 which may be supported by clamp members 141 attached to the various sections of the tubular body 13 at the flange sections 21, for example. The lower end of the feed pipe 139 couples to any of the lower circular rings, such as ring 101, and the upper end of the pipe 139 couples to an upper ring 143. Thus, fluid under pressure in the lower ring 101 will be transported upwardly to the upper ring assembly 99 through the vertical feed pipe 139.
The entire lower half surface of each of the lower rings 101, 103, and 105 are provided with a nozzle orifice pattern consisting of a plurality of orifices 145 that are adapted to spray outwardly and basically downwardly the liquid or gas media disposed under pressure in the rings through the feed pipes. This feature of the invention is best seen in FIGS. 6 and 7.
The upper ring 143 is also provided with orifices 145, but the orifice pattern is oriented so that the gas or fluid under pressure exiting the orifices will spray toward the area around the seal surface between the valve plug 47 and the valve seat 93. Although not shown in FIGS. 1 and 2, for the sake of clarity, the orifices 145 provide a uniform spray pattern, as shown in FIG. 7, looking at any cross section of a circular ring.
In operation, the tubular body 11, along with the upper valve arrangement and the upper and lower rings, are lifted by means of a crane, or the like, using the cable arrangement 23, and swung over a flaming well site. The valve plug 47 is now in its upper, "open" position so that as the tubular assembly is lowered over the well site, the oil or gas under high pressure will flow in an unimpeded manner upwardly through the length of the tubular body 11.
Once in place with the lower end 107 of the tubular lower section 15 resting on a well platform or the ground, the guy cables 25 are extended radially outwardly and anchored to appropriately positioned anchors such as "dead men", for example.
Depending upon the circumstances, the guying may take place either before or after fire retardant or oxygen inhibiting fluid or gas (arrow 147) is forced under pressure from conventional pump or pumps (not shown) through the feed pipes 109, 111, and 113, to the associated lower and upper rings and sprayed outwardly through the orifices 145. Preferably, the dimensions of the orifices are such that the emitted material will be atomized for maximum effectiveness to terminate and/or inhibit the combustion of the hydrocarbon products emanating from the well casing or head 22.
As any fire located at the lower area of the invention 11 is extinguished and prevented from re-igniting by the operation described above, the valve cable 75 is linearly moved by a conventional arrangement at the top of a crane's boom, for example, so as to cause the rack and pinion assembly 63 to rotated and force the conical plug member 47 downwardly against the upward force of the gushing oil or gas from the well head. As this is occurring, the upper ring arrangement 99, disposed about the valve seat 93, is spraying the fire inhibiting material to first quell and then prevent further combustion of any hydrocarbon product in the area of the valve seat. Thus, once the plug 47 is seated in the valve seat to force the gas or oil back down the inside of the tubular body 13, no combustion can occur at either the upper valve area or at the lower tubular end area.
It should be noted that the vertical, downwardly extending arm members 87 maintain the valve plug 47 in proper register and alignment with the annular valve seat 93 since the arm members 87 are guided by the rigid channel opening provided by the U-shaped channel member 39 and the inner channel-closing plate 41.
In accordance with another embodiment of the invention that is useable in oil and gas well fire situations where the well pressure is not so extreme, an alternate valve assembly 211 is shown in FIG. 8. Here, an annular valve seat member 213 is fixedly mounted at the upper end 215 of the upper tubular member 19', and an outwardly extending bracket member 217 is welded to the member 19' adjacent the end 215 and provided with a pin-accepting hole (not shown) at its outer end to hold a pivot pin 219 extending through a pivot arm section 221 of a flap valve pivot assembly 223.
The assembly 223 also includes a transverse member 225 that has eyelet holes 227 at an outer end, and 229 at an inner end. Also at the inner end of the member 225 is disposed a circular flapper valve lid member 231 that has a conical section seating surface 233 that is adapted to sealably fit into a mating inclined circular seating surface 235 of the valve seat member 213 when the member 223 is in its horizontal or "closed" position.
A first valve cable 237 is attached to the outer eyelet hole 227, and a second valve cable 239 is attached to the inner eyelet hole 229. In operation, upward tension is produced by any conventional means to the first valve cable 237 while slack is provided to the other valve cable 239. Such action causes the assembly 223 to pivot on the pin 219 from an "open" vertical position (dashed outline) to a horizontal "closed" position (solid outline). A cable-clearance wheel 241 is mounted on and above the outer end of the transverse member 225 so that the first valve cable 237 is moved outwardly when the transverse member is pivoted from its horizontal position to its vertical position, in order to prevent the cable from contacting and possibly interfering with the operation of the valve assembly. The valve is moved to its "open" position by reversing the tension on the two cables.
According to still another embodiment of the present invention, additional nozzle rings 311 are disposed between the upper ring 143 and the lower rings 101, 103, and 105 in order to provide additional protection against unintended ignition of any hydrocarbon product that may be in the area. An additional atomizer ring may best be viewed in FIG. 2.
In accordance with yet another embodiment of the present invention, one or more of the lower rings, other than the one feeding the vertical pipe leading to the upper circular ring, or an additional lower ring (not shown) may be fed with a cement-like non-flammable material under pressure that will build up a wall around the base of the tubular structure to additionally seal this area off from any oxygen or like flame-supporting gas or fluid.
The flame retardant material described in this specification may be any conventional liquid or gas chemical such as carbon dioxide, nitrogen, helium, and many others known in the art to inhibit flame support and/or ignition. In this regard, the ramifications of the use of water or a water-based chemical formulation in the operation of this invention should be carefully considered.
From the foregoing, it should be obvious that there has herein been described a new and improved oil and gas well fire extinguishing system that is easily constructed, economical to build, easy to transport, assemble and operate, and very quick and effective in function. Although several embodiments of the invention have been described in detail, it should be understood that additional embodiments and arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.
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A system, for extinguishing flames from combustible fluids exiting from a pipe, has an elongated tubular extinguisher body being disposable over the fluid emitting pipe, the extinguisher body having a lower inlet end and an upper outlet end and the body being adapted to accommodate a flow of the combustible fluid through the extinguisher body. A valve arrangement is mounted in the extinguisher body adjacent its upper outlet end for gradually limiting and finally eliminating the flow of the combustible fluid through the extinguisher body. Also, a flame inhibiting structure, including circular nozzle structures, are disposed adjacent the lower inlet end of the body and adjacent the valve arrangement and externally of the extinguisher body for preventing the support of combustion of combustible fluids adjacent the circular nozzle structures.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lens accommodating method and apparatus in a zoom compact camera.
2. Description of the Related Art
In a known zoom compact camera, a plurality of concentrical movable lens barrels (feed lens barrels) are moved between an accommodated position (i.e., a retracted position) and an advanced position. In the accommodated position, the front surfaces of the lens barrels are flush. When the lens barrels are advanced forwardly in an optical axis direction, steps (differences in the axial length of projection of the lens barrels from the camera body) are produced between the front surfaces of the lens barrels. The steps increase as the lens barrels are advanced. In other words, the front surfaces of the lens barrels are only flush with each other at the accommodated position.
If the lens barrels are moved forward (advanced) from the accommodated position, an inner lens barrel is protruded from an outer lens barrel, whatever the axial displacements of the lens barrels may be. Consequently, when the lens barrels are moved from the advanced position to the accommodated position, the inner lens barrel can interfere with an external member, immediately before reaching the accommodated position. In particular, in some compact cameras in which the front surface of the lens barrel (lens barrels) is closed or opened by a sliding barrier, the sliding barrier is released from a locked state immediately before the lens barrels reach the accommodated position. In this type of compact camera, if the sliding barrier is forcedly closed, there is a possibility that the inner lens barrel interferes with the sliding barrier.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a lens accommodation method and apparatus in which an inner lens barrel is retracted into an outer lens barrel before the lens barrels reach the completely retracted position.
To achieve the object mentioned above, according to an aspect of the present invention, there is provided a lens accommodating method in a zoom compact camera having a plurality of concentric lens barrels which are moved between a retracted position and an advanced position. The method includes retracting an inner lens barrel into an outer lens barrel before the lens barrels reach the retracted position when the lens barrels are moved from the advanced position toward the retracted position to thereby eliminate a step between front ends of the lens barrels in an optical axis direction, lens barrel and the moving the inner and outer lens barrel, the front ends of which are substantially flush with each other, to the retracted position together.
If the camera is provided with a sliding barrier which slides to open or close the front ends of the lens barrels when the lens barrels are at the retracted position, it is preferable that the step eliminating step terminates at a position in which the sliding barrier cannot interfere with the innermost lens barrel when the sliding barrier is moved to a closed position before the lens barrels reach the retracted position.
According to another aspect of the present invention, a lens accommodating method in a zoom compact camera having an inner lens barrel and an outer lens barrel which are moved between a retracted position and an advanced position, including retracting the inner lens barrel into the outer lens barrel before the inner and outer lens barrels reach the retracted position when the inner and outer lens barrels are moved from the advanced position toward the retracted position to eliminate a step between front ends of the inner and outer lens barrels in an optical axis direction, lens barrel and the moving the inner and outer lens barrel, the front ends of which are substantially flush with each other, together to the retracted position.
According to still another aspect of the present invention, there is provided a lens accommodating apparatus having a plurality of concentric lens barrels including an inner lens barrel and an outer lens barrel. A cam ring including cam grooves which are adapted to control a movement of the lens barrels and move the lens barrels between a retracted position and an advanced position. The cam grooves include step eliminating sections in which, when the lens barrels are moved from the advanced position to the retracted position, the inner lens barrel is retracted into the outer lens barrel to eliminate a step between the front ends of the inner lens barrel and the outer lens barrel in an optical axis direction before the lens barrels reach the retracted position, and integral accommodation sections in which the inner lens barrel and the outer lens barrel are moved to the retracted position while keeping the front ends thereof substantially flush with each other.
The cam ring can be made of one of the lens barrels or can be made of a rotary member separate from the lens barrels.
According to yet another aspect of the present invention, a lens accommodating apparatus is provided having an inner lens barrel and an outer lens barrel. A cam ring is provided having cam grooves which are adapted to control movement of the inner lens barrel and outer lens barrel and move the inner and outer lens barrels between a retracted position and an advanced position. The cam grooves include step eliminating sections in which, when the inner and outer lens barrels are moved from the advanced position to the retracted position, the inner lens barrel is retracted into the outer lens barrel to eliminate a step between front ends of the inner lens barrel and the outer lens barrel in an optical axis direction before the inner lens barrel and the outer lens barrel reach the retracted position, and integral accommodation sections in which the inner lens barrel and the outer lens barrel are moved to the retracted position while keeping the front ends thereof substantially flush with each other.
The present disclosure relates to subject matter contained in Japanese Patent Application No. 08-240778 (filed on Sep. 11, 1996) which is expressly incorporated herein by reference in its entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be discussed below in detail with reference to the accompanying drawings, in which:
FIG. 1 is a longitudinal sectional view of an upper half of a zoom lens barrel of a zoom compact camera shown in an accommodated position, according to the present invention;
FIG. 2 is a longitudinal sectional view of an upper half of a zoom lens barrel of a zoom compact camera at an intermediate focal length, according to the present invention;
FIG. 3 is a longitudinal sectional view of an upper half of a zoom lens barrel of a zoom compact camera at a longest focal length, according to the present invention;
FIG. 4 is an exploded perspective view of a zoom lens barrel of a zoom compact camera, according to the present invention;
FIG. 5 is a developed view of an outer lens barrel, according to the present invention;
FIG. 6 is a perspective view of a zoom compact camera to which the present invention is applied;
FIG. 7 shows the movements of the lens barrels immediately before the lens barrels reach the accommodated position, according to the present invention; and,
FIG. 8 shows the movements of the lens barrels immediately before the lens barrels reach the accommodated position, in the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As can be seen in FIG. 6, the embodiment of the present invention is applied to a zoom compact camera having a two-stage advancement type lens barrel 10. A camera body CB of the zoom compact camera is provided with a sliding barrier SB which slides laterally to close or open the front surface of the lens barrel 10.
The structure of the lens barrel 10 will be discussed below with reference to FIGS. 1 through 4.
The camera body CB includes a stationary ring 11 integral therewith, which is provided on the inner peripheral surface thereof with a female helicoid (internal thread) 11a. The female helicoid 11a is in mesh with a male helicoid (external thread) 12a formed on the outer peripheral surface of an outer lens barrel (element) (cam ring or drive ring) 12 which is fitted in the stationary ring 11.
The outer lens barrel 12 is provided with a spur gear 12b which is formed on a partial cut-away portion of the male helicoid 12a. The spur gear 12b is engaged by a zoom drive gear 13 which is rotatably supported by the stationary ring 11. The zoom drive gear 13 is driven by a zoom motor (not shown), so that when the zoom drive gear 13 is rotated, the outer lens barrel 12 is moved in an optical axis direction while being rotated, due to the screw- engagement between the male helicoid 12a and the female helicoid 11a.
The outer lens barrel 12 has a dual-cylinder structure of a substantially U-shaped section having an outer cylinder 12A and an inner cylinder 12B. The rear end of the outer lens barrel 12 is closed by a radial light intercepting wall 12C and is open at the front end. The inner cylinder 12B is provided on the inner peripheral surface thereof with cam grooves 12d and 12e for front and rear lens groups L1 and L2, respectively.
A linear movement guide ring 14 is fitted in the outer lens barrel 12 such that a rear end of the linear movement guide ring 14 protrudes from the outer lens barrel 12. A linear movement guide plate 15 is secured to the rear end of the linear movement guide ring 14. An inner flange 12f formed at the rear end of the outer lens barrel 12 is rotatably supported between the linear movement guide plate 15 and the linear movement guide ring 14, so that the linear movement guide ring 14 and the outer lens barrel 12 can rotate relatively but move together in the optical axis direction. The linear movement guide plate 15 is provided with radial projections 15a which are fitted in linear movement guide grooves 11b. The guide grooves 11b are formed on the inner peripheral surface of the stationary ring 11 and extend in parallel with the optical axis.
The linear movement guide ring 14 is provided with linear movement guide legs 14a which extend in parallel with the optical axis, so that an inner feed lens barrel (element) 16 which holds the front lens group L1 and a rear lens barrel (element) 17 which holds the rear lens group L2, are linearly guided and moved through the linear movement guide legs 14a, respectively. Specifically, the inner lens barrel 16 is provided with linear movement guide projections 16a which engage with the linear movement guide legs 14a, and the rear lens barrel 17 is provided with linear movement guide projections 17a which engage with other linear movement guide legs 14a. The linear movement guide projections 17a are provided with radially extending cam follower pins 17b which are engaged in the cam grooves 12e of the outer lens barrel 12.
The inner lens barrel 16 has a dual-cylinder structure which is substantially U-shaped in a longitudinal section, having an outer cylinder 16A and an inner cylinder 16B. The front end of the inner lens barrel 16 is closed by a radially extending light intercepting wall 16C and is open at the rear end. The inner lens barrel 16 having the dual-cylinder structure is fitted in the outer lens barrel 12 having the dual-cylinder structure. Namely, the inner cylinder 16B of the inner lens barrel 16, the inner cylinder 12B of the outer lens barrel 12, the outer cylinder 16A of the inner lens barrel 16, and the outer cylinder 12A of the outer lens barrel 12 are concentrically arranged in this order from the inner side (optical axis) With this arrangement, extraneous (harmful) light is prevented from entering the space between the outer lens barrel 12 and the inner lens barrel 16.
The linear movement guide projections 16a extend along the inner peripheral surface of the inner cylinder 16B of the inner lens barrel 16 and project at the rear ends thereof from the inner cylinder 16B. The projections 16a are provided, on the rear ends thereof projecting outward from the inner cylinder 16B, with cam follower pins 16b which are engaged in the cam grooves 12d of the outer lens barrel 12.
The inner lens barrel 16 is provided with a shutter unit mounting ring 16d integral therewith, to which an annular shutter unit 18 is secured. The annular shutter unit 18 is screw-engaged by a front lens barrel 19, at the center portion thereof, to which the front lens barrel 19 (which holds the front lens group L1) is secured. The shutter unit 18 rotates the front lens barrel 19 (front lens group L1) in accordance with object distance data to thereby move the same in the optical axis direction through the screw engagement therebetween, and opens and closes shutter blades SB in accordance with object brightness data, as is well known in the art.
FIG. 5 shows a developed view of the cam grooves 12d and 12e of the outer lens barrel 12 for the front and rear lens groups L1 and L2, respectively. The cam grooves 12d and 12e are each provided with a zoom section θ1 in which the front lens group L1 and the rear lens group L2 are driven between the telephoto extremity T and the wide angle extremity W, and an accommodation section θ2 in which the front lens group L1 and the rear lens group L2 are driven between the wide angle extremity W and the accommodated position S. Moreover, the cam groove 12dfor the front lens group L1 is provided with a step eliminating section θ2-1 and an integral accommodation section θ2-2 in the accommodation section θ2. The integral accommodation section θ2-2 extends in the circumferential direction of the ring (outer lens barrel) 12 and in parallel with the corresponding portion of the cam groove 12e for the rear lens group L2. The outer lens barrel 12 is moved in the optical axis direction while rotating, in accordance with the engagement of the helicoids 12a and 11a, and hence the lens barrels 12 and 16 can be moved to the accommodated position in spite of the circumferentially extending accommodation section θ2-2.
In the prior art, the track of the accommodation section θ2 of the cam groove 12d for the front lens group L1, i.e., the track of the accommodation section θ2 of the cam groove 12d, is defined by a straight line CP' connecting the wide angle extremity W and the accommodated position S, so that the step (the difference in the axial length of projection of the lens barrels from the camera body) between front surfaces of the lens barrels 12 and 16 is gradually increased when the lens barrels 12 and 16 are advanced from the accommodated position S.
However, in the present embodiment, a portion CP1 whose gradient is greater (i.e., the axial displacement of the inner lens barrel 16 per unit angular displacement is larger) than the cam track CP', and a portion CP2 (integral accommodation section θ2-2) parallel with the accommodation section θ2 of the cam groove 12e for the rear lens group, are provided instead of the cam track CP'.
The zoom lens barrel having the above construction operates as follows.
When the zoom drive gear 13 is rotated in the forward or reverse direction through the zoom motor, the outer feed lens barrel 12 is rotated in the forward or reverse direction and is moved in the optical axis direction while rotating. The inner cylinder 12B of the cam ring 12 is provided on the inner peripheral surface thereof with the cam grooves 12d and 12e in which the cam follower pins 16b and 17b of the inner lens barrel 16 and the rear lens barrel 17 are engaged, respectively. Since the inner lens barrel 16 and the rear lens barrel 17 are guided by the linear movement guide plate 15, the linear movement guide ring 14, the linear movement guide legs 14a, the linear movement guide projections 16a, and the linear movement guide projections 17a, respectively, the rotation of the outer lens barrel 12 causes the inner lens barrel 16 (front lens group L1) and the rear lens barrel 17 (rear lens group L2) to move in the optical axis direction in accordance with the cam profile of the cam grooves 12d and 12e.
If the outer lens barrel 12 and the inner lens barrel 16 are moved from the telephoto extremity T toward the accommodated position by rotating the outer lens barrel 12, the zooming operation by the front and rear lens groups L1 and L2 is carried out in the zoom sections θ1 of the cam grooves 12d and 12e. When the cam followers 16b and 17b enter the accommodation sections θ2, the inner lens barrel 16 is retracted faster than the outer lens barrel 12 along the cam profile CP1 in the step eliminating section θ2-1, so that the inner lens barrel 16 can be retracted into the outer lens barrel 12. Thus, the step between the inner and outer lens barrels 16 and 12 is eliminated. Thereafter, the inner lens barrel 16 is moved to the accommodated position S in the integral accommodation section θ2-2 (cam profile CP2) together with the outer lens barrel 12 and at the same speed as the outer lens barrel 12.
FIG. 7 shows the movement of the inner and outer lens barrels 16 and 12 immediately before they reach the accommodated position S. As mentioned above, the inner lens barrel 16 is retracted into the outer lens barrel 12 immediately before reaching the accommodated position S, so that the front surfaces of the inner and outer lens barrels are flush with each other (step eliminating section θ2-1). Thereafter, the inner lens barrel 16 and the outer lens barrel 12 are moved together to the accommodated position S (integral accommodation section θ2-2). If the sliding barrier SB is unlocked, at the position represented by the second stage (the third diagram from the bottom) in FIG. 7, and the sliding barrier SB is forcedly closed, the sliding barrier SB does not interfere or collide with the inner or outer lens barrels 16 and 12.
FIG. 8 shows the movement of the inner and outer lens barrels 16 and 12 when the inner lens barrel 16 is retracted using the cam track CP' of the prior art. In the prior art shown in FIG. 8, if the sliding barrier SB is unlocked at the position represented by the second stage (the third diagram from the bottom) in FIG. 8, and the sliding barrier SB is forcedly closed, the sliding barrier SB may interfere or collide with the inner lens barrel 16 which projects forward from the outer lens barrel 12 without being retracted into the outer lens barrel 12.
The above discussion has been directed to the movement of the lens barrels from the advanced position to the retracted position (accommodated position). The movement from the retracted position to the advanced position (wide angle extremity) occurs in the order opposite to the foregoing.
Although the illustrated embodiment is applied to a two-stage advancement type zoom lens having two lens groups, the present invention can be applied to a zoom lens barrel having more than two lens groups.
As can be understood from the above discussion, according to the present invention, an inner feed lens barrel of a plurality of concentric lens feed frames is accommodated in an outer feed lens barrel before the feed lens barrels are completely retracted into the camera body, so that a step between the front surfaces of the feed lens barrels in the axial direction can be eliminated. Consequently, no interference between an element (e.g., a sliding barrier) and the inner lens barrel occurs.
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A lens accommodating method in a zoom compact camera having inner and outer lens barrels which are moved between a retracted position and an advanced position includes the steps of retracting the inner lens barrel into the outer lens barrel before the inner and outer lens barrels reach the retracted position when the inner and outer lens barrels are moved from the advanced position toward the retracted position to thereby eliminate a step between the front ends of the inner and outer lens barrels in the optical axis direction, and moving the inner and outer lens barrels which are substantially flush with each other at the front ends thereof to the retracted position together. A lens accommodating apparatus is also disclosed.
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[0001] This application claims priority to provisional patent application Ser. No. 62/100,724, filed Jan. 7, 2015, to the extent allowed by law.
[0002] This invention relates to bit holders and combination bit/holders that are usable in connection with a shortened, generally 1½ inch depth bit holder block bores including a tailing curved segment beyond the 1½ inch annular bore of a bit holder block.
BACKGROUND OF THE INVENTION
[0003] Applicant is the inventor of the “quick change” bit holder/bit holder block combination that enables a bit assembly to have its bit holder retained in the bit holder block without the use of threaded nuts or spring clips holding the bit holder shank in the bit holder block bore. This invention is shown and discussed in applicant's U.S. Pat. Nos. 6,371,567, and 6,585,326 and RE44,690.
[0004] After the creation of the retainerless bit holder shank, applicant realized that the combination of a like tapered shank together with its corresponding bit holder block bore, when retained by an excessive interference fit made possible by an axial slot in the hollow shank, resulted in the greatest interference force being positioned adjacent the top of the terminus of the slotted distal tapered portion of the bit holder shank. The increased interference between the bit holder block bore and bit holder shank caused the minute radial and circumferential collapsing of the bit holder shank adjacent the axial oriented slot. The collapse became more prominent toward the distal end of the shank resulting in somewhat less radial and circumferential force being applied toward that distal end by the bit holder block bore. After the time of the conception of the invention found in the '567 and '326 patents, the positioning of greatest holding force between the bit holder shank and bitholder block bore adjacent the top of slot was utilized in an effort to ease the insertion of the bit holder in the bit holder block bore. That greatest portion of force to insert the bit holder shank was positioned at the last ¼ to ¾ inch of the insertion of the shank of the bit holder in the bit holder block bore. Additional holding force was added adjacent the top of the shank with a standard annular interference fit with the corresponding top portion of the bit holder block bore. These two greatest holding force positions, when added to the holding force positioned adjacent the remainder of the distal tapered portion of the shank resulted in the 3,000 to 15,000 lbs. necessary to insert and retain a lubricated shank in the bit holder block bore. These axial insertion forces are derived when preferably a molybdenum disulfide type lubricant is smeared on the shank of the holder. At least double the axial removal force is required when no lubricant is used.
[0005] In road milling machinery, bit assemblies are generally positioned around the outside of a cylindrical drum that is dimensioned to rotatably fit within the confines of the underside of a road milling machine. In an effort to create the smoothest road milling, bit assemblies have been mounted in staggered positions in spiral or chevron form on the drum to decrease the axial dimensions between adjacent cutting tips of bit assemblies. As a result of this spiral or chevron orientation and the positioning of many bit assemblies on a current milling drum, the spacing behind each bit assembly has been reduced to the point where access to the rear of each bit assembly is severely limited. This rear access is necessary in order to drive out shanks of broken bits, shanks of broken bit holders, and conical bits. The shorter bit holder shank and the shorter bit holder block bore now provide this access.
[0006] When increasing the rear access to the distal end of the shank by shortening the axial shank length and by shortening the axial length of the bit holder block bore, the holding force previously there is reduced. That shank to bit holder block bore retention force must be re-established.
[0007] A need has developed to provide an improved bit holder/bit holder block bore assembly wherein the holding force between a bit holder shank and a bit holder block bore may be positioned axially along the bit holder shank as desired, rather than as previously positioned on the aforementioned portions of the shank. Additionally, increased access to the rear of the bit holder block is desirable for easing the ability to drive the bit holder shank and bit shanks out of its bit holder block from the rear thereof.
SUMMARY OF THE INVENTION
[0008] The Invention resides in a shortened bit holder shank having a taper that is less than the taper or cylindrical portion of a bit holder block bore. Additionally, the invention resides in a bit holder block bore having a shortened bit block bore portion with a tailing arcuate bore segment behind the annular bore portion thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention may best be understood from the following detailed description of currently preferred embodiments thereof taken in conjunction with the accompanying drawings wherein like numerals refer to like parts, and in which:
[0010] FIG. 1 is a side elevational view of a combination bit holder and bit holder block constructed in accordance with the present invention;
[0011] FIG. 2 is a fragmentary cross sectional diagram, taken along line 2 - 2 of FIG. 1 showing the interference between the bit holder shank and the bit holder bore in the present invention;
[0012] FIG. 3 is a side elevational view of a first embodiment of a long shank bit holder positioned in a bit holder block of the present invention;
[0013] FIG. 4 is a side elevational view of a second embodiment of a long shank bit holder positioned in a bit holder block of the present invention;
[0014] FIG. 5 is a side elevational view of a bit holder having a shortened shank with a bulbous distal section of the bit holder shank;
[0015] FIG. 6 is a front elevational view of a modification of the bit holder shown in FIG. 5 wherein the bulbous section of the shank is of lesser bulbous degree;
[0016] FIG. 7 a is a side elevational view of a combination bit/bit holder with a shortened shank in accordance with the present invention and a diamond tip formed as a unitary structure;
[0017] FIG. 7 b is a side elevational view of a bit/bit holder combination having a diamond tip and a long shank shown as mounted in a bit holder block constructed in accordance with the present invention;
[0018] FIG. 8 a is a side elevational view of a bit/bit holder having a shortened shank constructed in accordance with the present invention wherein the tip of the bit/holder has an enlarged diameter tip insert mounted therein, all mounted in a bit holder block constructed in accordance with the present invention; and
[0019] FIG. 8 b is a side elevational view of the bit/holder of a modification of the bit/holder constructed in accordance with the present invention having a long shank, all mounted in a bit holder block constructed in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] Referring to FIGS. 1-2 , a combination of a short shank bit holder 10 mounted in a bit holder block 11 constructed in accordance with the present invention includes a bit holder having an upper body portion 12 and a lower generally 1½ inch long shank portion 13 depending from the bottom of the body portion thereof. The upper body portion 13 is about 2 inches in axial height making it longer than the shank 13 , the first holder to be so dimensioned. The shank is generally hollow and cylindrical approximating 1½ inches in diameter, 1½ inches in length, and includes an axially aligned elongate slot 14 through the wall of the shank extending upwardly from the distal end 15 of the shank to a terminus 16 subjacent a radially extending annular flange 17 about 2⅝ inches in diameter, defining the bottom of the body portion 12 of the bit holder 10 . The width of the slot 14 may be varied from about ⅛ inch to about ¾ inch depending on the amount of elastic deformation required to produce the desired holding force between the shank 13 and the bit holder block bore or a base block bore 18 . In this embodiment, the bit holder shank includes an upper annular portion 20 ( FIG. 2 ) sized to have a conventional interference fit of about 0.001-.005 inch greater than the corresponding bit holder block bore or base block bore 18 adjacent the top 21 of the bit holder block.
[0021] A central reduced diameter portion 22 ( FIG. 2 ) of the shank 13 depends from the upper previously mentioned enlarged portion 20 . The upper terminus 16 of the slot 14 is generally, although not always, positioned in this central reduced diameter 22 zone. In this embodiment of the invention, a lower tapered portion 23 extends from the bottom of the upper reduced diameter portion 22 to a position adjacent a distal end 15 substantially annular flange of the bit holder shank 13 . This tapered portion 23 , to be discussed in more detail below, includes what is termed herein “a reverse taper portion.” This reverse taper portion is, with respect to any taper or straight cylindrical bit holder block bore 18 , also to be discussed in greater detail below. The distal, mainly annular, flange 15 is a reduced diameter portion defining about the last ¼ inch length of the shank 13 and is annular with the exception of the slotted portion 14 discussed previously.
[0022] This shortened, reverse taper, shank 13 on the bit holder is an improvement over the shortened bit holder shank shown in applicant's co-pending provisional application 61/944,676 filed Feb. 26, 2014, the written and drawing contents of which are incorporated herein by reference.
[0023] The bit block 11 shown in FIGS. 1, 3-4 incorporating the present invention includes a drum mounting portion 24 having a generally flat, or somewhat concave arcuate, base 25 including a plurality of mounting holes 26 - 26 or apertures therein for mounting the base on a drum (not shown). In this embodiment, the plane of the base 25 intersects the center line 27 of a bit holder 10 mounted in the bit holder block 11 at an acute angle thereto. The bit holder block body further includes a forward end adjacent portion 24 of the bit block 11 that in this preferred embodiment includes a peaked center line 28 together with sloped surfaces on either side of the center line (only one shown), aiding in directing material to be removed by the bit assembly from whatever substrate the milling machine is operating on.
[0024] Outwardly of the drum standoff mounting portion 24 of the bit holder block 11 is a generally annular bit holder receiving portion 30 including a flat annular surface defining the top 21 thereof on which the bottom annular flange 17 of the bit holder body 12 is positioned generally contiguous therewith. The annular bit holder mounting portion 30 extends to an outer generally semicircular portion and includes a bit holder block bore 18 which, in this embodiment, has a continuous constant taper surface extending from its top flat annular surface 21 past a bottom semi-annular surface 31 about 1½ inches axially from the top annular surface and further including an arcuate concave surface portion 32 extending below the bottom of the annular bit holder block bore mounting portion 30 at a constant tapered angle continuation of the bit holder block bore that extends from that bottom surface, at 32 , toward the bottom of the bit block mounting portion.
[0025] In this preferred embodiment, the bit holder block bore 18 is a constant taper, or straight cylindrical bore and extends from the top surface 21 through to the bottom of the concave block mounting portion shown at C. It will also be understood that some bit holder block bores 18 may be divided into multiple portions wherein the taper of the top portion of the bit holder block bore is greater than the taper or semi-cylindrical portion of a bottom section of the bit holder block bore. This holder 10 and holder block bore 18 relationship can be opposite in taper and achieve the same results. Additionally, the bottom of the annular bit holder receiving portion of the bit holder block bore includes a slot, whose interiormost outline is shown in dotted line at D that extends from the outermost bottom portion of the bit block bore at C to provide increased access to the rear of the bit holder block bore 18 for use of a tool to drive a broken bit shank or bit from the bit holder bore.
[0026] As stated in applicant's provisional application Ser. No. 61/983,291, filed Apr. 23, 2014, entitled “Improvements in Rear of Base Block” the inclusion of a cut out portion 31 , 32 of the rear of the base holder mounting portion 30 of the base block 11 shown at surface C shortens the annular bit holder receiving portion of the bit holder base block from approximately 2⅝ inches in axial dimension to about 1½ inches in axial dimension, increasing the open area behind the bit holder block that allows an easier access to the rear of the bit holder block for a removing tool or punch bar or other shape extractor (not shown). The written contents and drawings of the aforementioned provisional application entitled “Improvements in Rear of Base Block” are incorporated herein.
[0027] Referring to FIG. 2 , a fragmentary silhouette of the shank of the bit holder shown in FIG. 1 is shown contrasted to the dimensions of the bit holder block bore shown in FIG. 1 as they appear in overlapping relation showing the relative dimensions of each with respect to the other. The outline of the bit holder shank is shown at line B while the outline of the bit holder block bore is shown at line A. The outline of the bit holder is shown beginning at an axially extending tire portion 33 through the bit holder body annular flange 17 to a generally rounded annular undercut 34 extending to the top of the bit holder shank. This top of the bit holder shank includes the larger upper portion 20 disclosed above, the central reduced annular portion 22 and the bottom reverse taper portion 23 extending to the generally reduced diameter annular flange defining the distal end 15 of the shank.
[0028] The bit holder shank line A starts at annular flange 17 adjacent the top of the bit holder shank portion 17 of the bit holder and extends from that undercut 34 at a continuous angle to the bottom of the annular portion 15 of the bit holder shank. As shown most clearly at the bottom of the upper portion 20 of the bit holder shank 13 , there is a standard interference between the bit holder shank upper portion 20 and the bit holder block bore, Line A. It should be noted that this upper portion may also be tapered to conform with the angle of taper of the top of the bit holder block bore to provide an annular surface interference rather than an annular line interference.
[0029] From adjacent the upper portion 20 of what is termed the reverse taper portion 23 of the bit holder shank 13 to the bottom 15 thereof, there is an interference with the bit holder block bore, Line A, that increases toward the bottom end 15 of the tapered bit holder shank portion, i.e., in this preferred embodiment from about 0.015 inch on a diameter at the top to about 0.035 inch on a diameter at the bottom portion of the shank 15 . This “reverse taper” only has to be a less tapered portion than that of the adjacent bit holder block bore, Line A. In other words, if the taper of the bit holder block bore Line A is 1 degree per side, the reverse taper of the bit holder shank 13 would only have to be something less than that, i.e., ½ degree per side. If the bit block holder bore is cylindrical, the reverse taper portion of the bit holder shank would only have to be a negative taper of ½ degree, 1 degree, etc. per side.
[0030] It should be noted that “reverse taper” in this connection means a differing slope between the distal slotted portion 16 of the bit holder shank 13 and the corresponding shank engaging portion of the bit holder block bore, Line A. As shown in FIG. 2 , the difference in slope increases as one approaches the distal end 15 of the shank. The specific numbers are not as important as the relationship between the surfaces shown most clearly in outline in FIG. 2 . The invention distributes the circumferential and radial loads, between the shank and bit holder block bore in the approximate ¾ inch distance of interference sufficiently to hold the shank 13 in the bore 18 during use.
[0031] The reason for the reverse taper 23 is to move the position at which a greater interference force is exerted at the distal end 15 of the shank than could be achieved with the same interference angles between the shank of the holder and the base block bore. As noted above, in previous versions of the “quick change” bit holder and bit holder block assembly, the taper or cylindrical portions of the bit holder shank and bit holder block bore were identical in configuration and it resulted in the greatest interference being adjacent the top of the slotted portion of the shank. By using a lesser taper on the bit holder shank than that of the bit holder block bore, the area of greatest interference or holding force between the bit holder block bore and the bit holder shank may be moved lower on the shank near distal end 15 and also may be spread over a greater axial length than that utilized in the prior art. The 5,000 to 20,000 pounds axial force necessary to insert the bit holder 10 in the bit holder block bore 18 may be modified as needed along the reverse taper portion 23 as desired. The reverse taper of the shank yields a nearly equivalent radial retention force as the axial insertion force. However, the retention force increases as impact forces tend to improve mating surface tension.
[0032] The recognition that previously known interference fits between a slotted bit holder shank and a bit holder block bore was obtained adjacent the top of the tapered portion and near the top of the slot of the bit holder shank has enabled applicant to realize that the axial length of the shank may be decreased from approximately 2⅝ inches in length to about 1½ inches in length with the same retention force: 1) as long as the reverse taper improvement is utilized in the interfering portion of the bit holder shank 23 and the bit holder block bore 18 , or 2) if similar shank/bore tapers are used with increased interference from that disclosed in applicant's prior U.S. Pat. Nos. 6,371,567 and 6,585,326 on the order of 0.019 to 0.033 inches of diametrical interference and as long as the tensile and the compressive strength of the bit holder shank is increased by about 20% above the same values used in the reverse taper shank parameters, same taper can yield workable results. This decreased axial length of the bit holder shank and the bit holder block bore enables the bit holder block bore to be axially reduced in length to provide space for additional access of a bit removing tool (not shown) to the rear 31 , 32 of the bit holder block.
[0033] As shown in FIG. 3 , when a bit holder having a shortened 1½ inch long shank, shows sufficient wear that it needs to be replaced, it may not only be replaced with another bit holder having a 1½ inch long shank ( FIG. 4 ), but in accordance with applicant's invention, it may be replaced by what may be termed a standard “quick change” bit holder 40 having a 2⅝ inch long shank. Bit holder block bore 18 enlarge after extended use may also necessitate use of the longer shank bit holder 40 . In this application, the bottom tapered portion 42 of the bit holder shank 41 extends not only in the bottom portion of the 1½ inch long fully annular bit block bore 18 , but also impinges against the continuing concave segment surface 43 of the bit holder block bore 18 extending below the back face C ( FIG. 1 ) of the annular portion of the bit holder block 11 toward the bottom of the bit holder block mounting portion 25 at a constant angle thereto. This additional interference bore portion or segment 43 will provide added retaining force between the bit holder block 11 and the bit holder shank 41 to retain the new shank therein even though the top of the bit holder block bore 18 may be enlarged by repeated pounding and use of the road milling machine (not shown) to an extent no longer permitting use of a shorter shank bit holder 10 ( FIG. 1 ).
[0034] Referring to FIG. 4 , a modification of the invention shown in FIG. 3 is utilized at 45 with the bit block 11 shown in FIG. 3 and provides a bit holder that has its upper body portion 46 identical to that shown in FIG. 3 . A shank portion 47 , while similar to that of the 2⅝ inch long shank shown in FIG. 3 , that has a portion of the lower interference section of the shank 47 preferably 180 degree segment of the bit holder shank removed at 48 to provide added access for an extractor tool (not shown) or punch to be utilized when extraction of the bit holder 45 , broken bit shank, or bit is removed from its mounting in the bit holder block bore 18 .
[0035] By positioning the portion of the bit holder shank 47 ( FIG. 4 ) having the slot 14 therein away from the concave tail portion 43 of the bit holder block bore 18 , and by removing the outermost portion of the bit holder shank, the inner portion 47 a of the bit holder shank is capable of providing increased interference sufficient to maintain the bit holder 45 in the shortened bit block bore 18 . By utilizing the reverse taper at 51 , defined as a taper less than the taper or cylindrical bit block bore, the position of interference force may be located anywhere along the bottom interference portion of the bit holder shank as desired. This allows not only greater use of bit holders, but allows additional longevity for bit holder blocks 11 even after the upper portion of the bit holder block bore 18 has been enlarged by repeated usage.
[0036] Differing Shape Bit Holder Shanks
[0037] Referring to FIG. 5 , a second embodiment of the bit holder 55 having a shortened shank 56 thereon, constructed in accordance with the present invention, includes a bit holder body 57 substantially identical to that of the first embodiment shown in FIG. 1 and a shortened bit holder shank 56 about 1½ inches in axial length that has a top larger radial portion 58 and a reduced diameter central portion 60 substantially identical to the first embodiment shown in FIG. 1 . However, the lower interference portion 61 of the bit holder shank includes a generally bulbous substantially annular section, with the exception of the axial slot 62 which forward end is positioned forward of the interference section as desired to provide sufficient interference between the bit holder block bore and the bit holder shank 61 .
[0038] Referring to FIG. 6 , a third embodiment 65 of the present invention is shown which is substantially identical to the second embodiment of the invention, with the exception that the lower interference portion 63 of the bit holder shank 64 is created in a flatter bulbous shape which is outwardly extending, although greater axially extending than that shown at 61 in FIG. 5 . This modification of the bit holder shank 64 would have about equal radial retention force as that of the second embodiment 55 shown in FIG. 5 .
[0039] Bit/Holders Utilizing Diamond Tips and Shanks in Accordance with the Present Invention.
[0040] Referring to FIGS. 7 a and 7 b , a fourth embodiment 65 and modification 66 of the present invention includes a bit/holder unitary assembly having a bit holder body 67 , 68 , respectively, in combination with a tungsten carbide base insert diamond coated or combination diamond and cobalt incorporated matrix tip insert 70 , 71 , respectively, mounted on a tungsten carbide base 72 , 73 , respectively, that is in turn mounted in the top cylindrical portion of a bit holder body 65 - 66 . The dimensions of the unitary tip, tungsten carbide base, and steel body portions are substantially identical to that utilized with a combination bit and bit holder body previously utilized in the trade (U.S. Pat. No. 8,118,371). The diamond coated insert 70 , 71 is about 0.565 inch in diameter. This identical height of the bit/holder top portion 67 , 68 provides use when mounted on a bit block on a road milling machine (not shown.
[0041] In FIG. 7 a , the bit/holder unitary structure further includes a reverse taper shortened shank 74 similar to that shown in FIGS. 1 and 5-6 as mounted in a bit holder block 11 constructed in accordance with the present invention as shown in FIG. 1 . The shortened bit holder shank 74 of FIG. 7 a includes, as in FIG. 1 ) not only a top increased diameter portion and a central reduced diameter portion, but a lower reverse taper interference portion and a distal reduced diameter generally annular portion as described above with FIG. 1 .
[0042] As shown most clearly in FIG. 7 a , this embodiment provides increased access to the rear of a bit holder block 11 to provide ease of access for extraction of the bit/holder from the bit holder block bore when desired.
[0043] FIG. 7 b discloses a bit/holder 68 having a top portion substantially identical to that shown at 67 in FIG. 7 a with a diamond coated or a diamond tip with a diamond cobalt matrix 71 , a tungsten carbide base 73 , and a top holder body portion 68 together with a quick change slotted shank 75 having an axial length approximating 2⅝ inches that includes a top increased diameter portion, a central reduced diameter portion and a bottom reverse taper portion 76 . The bottom reverse taper portion 76 not only provides interference with the 1½ inch long annular bit holder block bore, but also provides interference with the inner concave tail or continuing taper portion 43 in FIG. 4 of the bit holder block bore extending onto the back of the block mounting portion. This bit/holder 66 will be utilized when the bit holder block bore has been enlarged sufficiently that a shortened shank on a bit/holder 65 such as shown in FIG. 7 a will not be sufficiently retained in the bit holder block bore.
[0044] Referring to FIG. 8 a , a fifth embodiment 80 of the bit/holder of the present invention is shown including an enlarged diameter tip 81 having a base greater than ⅝ inch in diameter (shown as ¾ inch in diameter) which is mounted on a vertical extension of the steel body 82 that is surrounded by a tungsten carbide annular ring 83 . The steel body includes an upper generally cylindrical portion and a lower diametrically enlarged base or tire portion 84 of the body that, as shown in the previous embodiment, sits on the top of a bit holder block receiving portion 21 .
[0045] As with the embodiment shown in FIG. 7 a , the embodiment shown in FIG. 8 a includes a shortened reverse taper slotted shank 85 constructed in accordance with the present invention generally as shown in FIG. 1 and which may also include shanks such as shown in FIGS. 5 and 6 .
[0046] Referring to FIG. 8 b , a bit/holder 90 constructed in accordance with the present invention includes a top tip 91 and body portion 92 substantially identical to that shown in FIG. 8 a with a reverse taper standard length shank 93 about 2⅝ inches in length that may be utilized in connection with the bit holder block 11 of the present invention. When the bore of the bit block is worn sufficiently, it would not retain the shorter shank bit/holder therein. The 2⅝ inch length shank 93 shown in FIG. 8 b would, as the previous embodiments have, include an upper enlarged diameter portion, a central decreased diameter portion, and a lower reverse taper portion 94 that provides interference not only with the bottom of the bit holder block bore 18 ( FIG. 1 ) but also with the concave tail 43 ( FIG. 4 ) or segment of the bit holder block bore 43 extending onto the block mounting portion. As with the previous embodiments, as long as the taper of the taper portion of the shank is less than that of the bit holder block bore taper or cylindrical segment, increased interference force may be positioned anywhere along the shank as desired so as to retain the shank 93 in the bit holder block bore.
[0047] While five embodiments have been shown and described, it will be understood by those skilled in the art that many changes and modifications may be made without departing from the true spirit and scope of the present invention. It is the intent of the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.
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Bit holders and combination bit/bit holders with shortened quick change shanks that are selectably retainable in complementary base block bores that are likewise shortened for providing added spacing at the rear of base blocks. When a plurality of such base blocks are mounted in close proximity on a drum or endless chain, the added spacing provides ease of holder replacement and easy access at the rear of the bit holder base block bore.
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BACKGROUND
[0001] 1. Field of Invention
[0002] The present invention is directed to a downhole cutting tool and, in particular, a downhole radially expandable fluid jet cutting tool.
[0003] 2. Description of Art
[0004] Various types of cleaning or cutting jet blasting arrangements have been proposed and used for jet blasting or eroding surfaces with abrasive fluids including, by way of example only, steam, water or any other fluid along with or without an abrasive substance in an attempt to accomplish whatever results may be desired.
[0005] Generally the fluids are conducted through a fluid passage in the arrangement and discharged through a restricted orifice in a jetting nozzle to increase the velocity of fluids and abrasive particles in an attempt to increase the cutting or cleaning effect desired. The jetting nozzle is available in a variety of designs and sizes and is normally produced from an extremely hard and/or tough material such as, by way of example only, carbide. It is generally accepted that the closer a jetting nozzle is to the surface to clean or cut the higher the efficiency of the operation.
[0006] One such prior jetting tool apparatus is disclosed in U.S. Pat. No. 5,765,756. The jetting tool apparatus of this patent includes multiple extendible telescoping jetting nozzles that are rotated into position by fluid flowing through the tool. In addition to rotation, the jetting nozzles extend telescopically so as to come in close contact with the cutting surface. After the cutting is completed, however, the nozzles remain extended. They are rotated downward into recesses to facilitate movement of the tool out of the wellbore. In those instances where the tool is to be moved to a new location for continued jetting, the telescopically extended jetting nozzles can not be reconfigured to a lesser extension because the telescoping members cannot be retracted to their original positions. As a result, the tool in U.S. Pat. No. 5,765,756 is limited in its use and requires removal of the tool from the well and resetting of the telescoping jetting nozzles before the tool can be used in a new, narrower, location. As is apparent, removal of the tool for resetting and subsequent repositioning in the well is time consuming and costly.
SUMMARY OF INVENTION
[0007] The present invention overcomes the deficiencies of U.S. Pat. No. 5,765,756 while providing additional benefits not found in prior jet cutting tools. For example, the jet cutting tools and methods of cutting a surface of a wellbore of the present invention provide the capability to extend and retract the jetting nozzles for easy and quick relocation and redeployment within a well without the need for removal of the tool from the well; permit the jetting nozzles to be consistently extended to the cutting surface; maintain the jetting nozzles in the appropriate orientation during cutting; permit easy and efficient cutting of casing when passing through a restriction in the casing or when cutting a surface in relatively shallow water depth; permit efficient cutting in multiple locations within conduits having variable inner diameters; and provide the capability of cutting in large diameter conduits and then be redeployed for cutting in small diameter conduits without having to remove the tool from the wellbore.
[0008] Broadly, the present invention is directed to a jet cutting tool having one or more arms that are extendable radially from the body of the tool. Each arm is in fluid communication with a passageway within the tool. An actuating member, such as a piston, is disposed within the passageway. Each arm includes a cutting head disposed on the end. The cutting head may include a metal cutting element such as crushed carbide or other carbide elements. Cutting fluid, such as an abrasive slurry known to persons skilled in the art, is pumped at high pressure down the passageway and moves the piston. The piston in turn extends each of the arms until each arm is in contact with the inner wall surface of the cutting surface or casing of the well. Cutting fluid is also forced into a length of tubing in fluid communication with the passageway and the cutting head. After extension of the arms to the point where the piston is no longer movable by the cutting fluid, the cutting head is positioned next to, and preferably in contact with, the cutting surface. The cutting fluid is then forced through the length of tubing from the passageway to the cutting head and out of the nozzle at a high pressure. The high pressure of the cutting fluid being expelled from the nozzle of the cutting head cuts the casing or other cutting surface.
[0009] After cutting, the pressure of the cutting fluid flowing through the passageway is decreased and the piston is retracted. Accordingly, the arms are also retracted so that the jet cutting tool can be moved to a new location and the arms redeployed for additional cutting. Advantageously, the retraction and the extension of the arms are fully repeatable such that the jet cutting tool can be used in multiple locations having multiple inner diameter, including cutting narrower portions of casing after cutting wider portions of casing.
[0010] In accordance with one aspect of the invention, one or more of the foregoing advantages have been achieved through a downhole jet cutting tool. The downhole jet cutting tool comprises a housing having an upper end for connection to a conduit string for running the downhole jet cutting tool into a well, the housing having a passageway for communicating a cutting fluid pumping down the conduit string to the downhole jet cutting tool; an actuating member operatively associated with the passageway whereby the actuating member is actuable by the cutting fluid, the actuating member having an initial position and a plurality of actuated positions; and a jet nozzle assembly, the jet nozzle assembly comprising an arm operatively associated with the actuating member whereby the arm is moved from a retracted position to one of a plurality of extended positions by the actuating member moving from the initial position to a corresponding actuated position, the arm having a cutting end and pivot end, the pivot end being pivotally connected to the housing, and the cutting end having a nozzle for expelling the cutting fluid, wherein the passageway of the housing and the nozzle of the cutting head are in fluid communication with each other such that the cutting fluid can flow from the passageway and out of the nozzle at a pressure sufficient to cut a cutting surface disposed within the well.
[0011] A further feature of the downhole jet cutting tool is that the cutting head may be pivotally connected to the arm. Another feature of the downhole jet cutting tool is that the housing may have an opening leading from the passageway to an exterior portion of the housing, and the arm may have a portion that extends through the opening into the passageway in engagement with the actuating member. An additional feature of the downhole jet cutting tool is that the passageway and the nozzle may be in fluid communication with each other through a flexible tubing. Still another feature of the downhole jet cutting tool is that the flexible tubing may be in fluid communication with the passageway through a port disposed in the housing above the actuating member. A further feature of the downhole jet cutting tool is that the housing may include a recess for receiving the jet nozzle assembly when the arm is in the retracted position. Another feature of the downhole jet cutting tool is that the actuating member may comprise a piston located in the passageway that is acted on by the cutting fluid flowing down the passageway. An additional feature of the downhole jet cutting tool is that the actuating member may include a biasing member for biasing the actuating member toward the initial position. Still another feature of the downhole jet cutting tool is that the biasing member may comprise a coil spring. A further feature of the downhole jet cutting tool is that the cutting head may include at least one standoff for contact with the cutting surface in the well while the arm is in one of the extended positions. Another feature of the downhole jet cutting tool is that at least one of the at least one standoffs may comprise a roller. An additional feature of the downhole jet cutting tool is that the roller may have an outer surface with at least one groove disposed on the outer surface. Still another feature of the downhole jet cutting tool is that at least one of the at least one standoffs may comprise a carbide dome button.
[0012] In accordance with another aspect of the invention, one or more of the foregoing advantages have been achieved a downhole jet cutting tool for cutting a tubular member in a well. The downhole jet cutting tool comprises a housing having an upper end for connection to a conduit string for lowering the housing into the tubular member, the housing having a passageway; a piston in the passageway for movement between upper and lower positions; a spring in the passageway for urging the piston toward the upper position; an arm having an upper portion pivotally connected to an exterior portion of the housing at a pivot point, the arm having a cam portion that extends through an opening in the housing into the passageway below the piston so that cutting fluid being pumped down the conduit string moves the piston downward from the upper position, causing the piston to push downward on the cam portion of the arm to pivot a lower portion of the arm outward from the housing; a cutting head with a nozzle attached to the lower portion of the arm for engaging the tubular member; and a flexible tube extending from a port in the housing above the piston to the cutting head for delivering cutting fluid being pumped down the conduit string to the nozzle.
[0013] In accordance with still another aspect of the invention, one or more of the foregoing advantages have been achieved a method of cutting a casing disposed within a well. The method comprising the steps of: (a) running a downhole jet cutting tool on a conduit string into a tubular member of a well to a first location, the downhole jet cutting tool having an actuating member biased toward an initial position and an arm with a cutting head, the arm being pivotally movable from a retracted position by movement of the arm from the initial position; (b) pumping a cutting fluid down the string, which exerts a force on the actuating member to move the actuating member from the initial position, causing the arm to pivot from the retracted position and move the cutting head outward into contact with a surface of the tubular member; (c) continuing to pump the cutting fluid down the string, which flows to and out of the cutting head, resulting in the tubular member being cut; and (d) after the tubular member has been cut, stopping the pumping of cutting fluid down the string, which allows the actuating member to return to its initial position and, thus, causing the arm to return to the retracted position.
[0014] A further feature of the method of cutting a casing disposed within a well is that the actuating member in step (a) may comprise a piston. Another feature of the method of cutting a casing disposed within a well is that the method may further comprise the step of moving the downhole jet cutting tool to a second location within the well after completion of step (d) and repeating steps (b) and (c). An additional feature of the method of cutting a casing disposed within a well is that the second location may be narrower than the first location. Still another feature of the method of cutting a casing disposed within a well is that step (a) may comprise pivotally mounting the arm to a housing of the jet cutting tool at a pivot point; and step (b) may comprise exerting a downward force by the actuating member on a portion of the arm inward from the pivot point.
[0015] The jet cutting tools and methods of cutting a surface in a wellbore disclosed herein have one or more of the following advantages: providing the capability of extending and retracting the jetting nozzles for easy and quick relocation and redeployment within a well; permitting the jetting nozzles to be consistently extended to the cutting surface; maintaining the jetting nozzles in the appropriate orientation during cutting; permitting easy and efficient cutting of casing when passing through a restriction in the casing or when cutting a surface in relatively shallow water depth; permitting efficient cutting in multiple locations within conduits having variable inner diameters; and providing the capability of cutting in large diameter conduits and then be redeployed for cutting in small diameter conduits without having to remove the tool from the wellbore.
BRIEF DESCRIPTION OF DRAWINGS
[0016] FIG. 1 is a cross-sectional view of one embodiment of the jet cutting tool of the present invention shown in its retracted or run-in position.
[0017] FIG. 2 is a cross-sectional view of the jet cutting tool illustrated in FIG. 1 shown in its extended or cutting position.
[0018] FIG. 3 is a top view of a cutting head of one specific embodiment of the jet cutting tool of the present invention.
[0019] FIG. 4 is a top view of another cutting head of one specific embodiment of the jet cutting tool of the present invention.
[0020] FIG. 5 is a perspective view of a roller for one embodiment of the jet cutting tools of the present invention.
[0021] While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0022] Referring now to FIGS. 1-2 , jet cutting tool 20 is shown in its retracted or “run-in” position ( FIG. 1 ) and an extended or cutting position ( FIG. 2 ). Jet cutting tool 20 has housing 22 with passageway 24 extending longitudinally into upper end 23 of housing 22 . Upper end 23 is adapted to be connected to string of conduit 10 , such as tubing or drill pipe, through any device or method known to persons of ordinary skill in the art. The lower portion of housing 22 is solid, with passageway 24 having a bottom 25 approximately midway along the length of housing 22 .
[0023] Actuating member such as piston 26 is slidingly engaged within passageway 24 of housing 22 . Resilient seal 28 provides a seal with piston 26 along the wall of passageway 24 . Preferably, a retaining member such as coil spring 30 is disposed adjacent piston 26 for urging piston 26 upward. As discussed in greater detail below, spring 30 is expanded when jet cutting tool 20 is in its retracted position ( FIG. 1 ) and compressed when jet cutting tool 20 is in its extended position ( FIG. 2 ). Therefore, spring 30 is biased for retaining piston 26 in an initial or upper position in which jet cutting tool 20 is in its retracted position.
[0024] Housing 22 also includes a plurality of rectangular openings 32 (only one shown) extending through its side wall, into which part of a jet nozzle assembly 40 is received when jet cutting tool 20 is in its retracted position. Although only one jet nozzle assembly 40 is shown, typically tool 20 has three or more jet nozzle assemblies 40 . Housing 22 also has a recess 33 on its exterior into which the remaining portion of jet nozzle assembly 40 locates. Opening 32 extends from passageway 24 to recess 33 and has a shorter axial length than recess 33 . The lower end of opening 32 coincides with passageway bottom 25 . Housing 22 also preferably includes radially extending flanges 34 , 36 at its upper and lower ends for protecting jet nozzle assembly 40 when jet cutting tool 20 is in its retracted position.
[0025] Port 38 , which is located above piston 26 in housing 22 , provides fluid communication from passageway 24 to jet nozzle assembly 40 . Jet nozzle assembly 40 comprises arm 42 , tubing 44 , and cutting head 50 . Preferably, tubing 44 is flexible. Tubing 44 is in fluid communication with passageway 24 and cutting head 50 . Couplings 45 , 46 attach tubing 44 to passageway 24 and to cutting head 50 , respectively. Preferably, cutting head 50 is pivotally attached to arm 42 by a fastener such as pin 47 or any other device that is capable of attaching cutting head 50 to arm 42 and allowing cutting head 50 to rotate or pivot relative to arm 42 . Accordingly, cutting head 50 can pivot about the point of connection with arm 42 to facilitate better contact with the inner wall surface 61 of casing 60 ( FIG. 2 ).
[0026] A pivot end of arm 42 is connected to housing 22 within the upper end of recess 33 by a fastener such as pin 49 or any other device that is capable of attaching the pivot end of arm 42 to housing 22 and allowing arm 42 to rotate or pivot about pivot pin 49 . A lever or cam 48 is integrally formed on the upper end of arm 42 and extends through opening 32 into passageway 24 in contact with the lower end of piston 26 . Cam 48 contacts piston 26 at a point that is radially inward and upward from pivot pin 49 , creating a moment arm. Downward movement of piston 26 pushes downward on cam 48 , causing arm 40 to pivot outward to the position shown in FIG. 2 . Preferably, flanges 34 , 36 protect arm 42 , cutting head 50 , and tubing 44 of jet nozzle assembly 40 when arm 42 is in its retracted position ( FIG. 1 ). As shown in FIG. 1 , in a preferred embodiment, tubing 44 has little or no slack in it when jet cutting tool 20 is in the retracted position. Therefore, the risk of tubing 44 being damaged or broken when jet cutting tool 20 is being run into the well is lessened.
[0027] Cutting head 50 has passage 52 disposed therein. Passage 52 is in fluid communication with coupling 46 and, thus, tubing 44 and passageway 24 . Cutting head 50 also includes opening 54 with, nozzle 56 . As shown in the embodiment of FIGS. 1 and 2 , passage 52 in cutting head 50 includes plug 59 . Plug 59 is used to close one end of passage 52 when passage 52 is formed by drilling all the way through cutting head 50 . In other words, plug 59 may be included if certain methods of manufacturing cutting head 50 are utilized.
[0028] Cutting head 50 also preferably includes one or more standoffs 58 that engage the wall surface of casing 60 ( FIG. 2 ) and facilitate maintaining cutting head 50 and, thus, jet cutting tool 20 in place. Standoffs 58 preferably also provide guidance of cutting nozzle 56 in the same track. As shown in FIGS. 1 and 2 , standoffs 58 may comprise dome buttons formed of a hard, wear resistant material such as tungsten carbide. In other embodiments, standoffs 58 are polymer elements. In still other embodiments, shown in FIGS. 3-5 , standoffs 66 are bearing units such as rollers 58 having grooves 67 (shown in FIG. 5 ) to facilitate gripping the inner wall surface of casing 60 .
[0029] Standoffs 58 may be arranged in any manner to facilitate the desired type of cut in casing 60 . For example, as shown in greater detail in FIG. 3 , standoffs 58 are rollers 66 for rolling axially along the inner wall surface of casing 60 ( FIG. 2 ) in the direction of arrow 63 and arrow 65 when cutting tool 20 is making an axial cut. Alternatively, as shown in FIG. 4 , rollers 66 may be rotated 90 degrees, i.e., perpendicular to rollers 66 shown in FIG. 3 , such that they rotate and, thus, cut, in the direction of arrows 68 and 69 when cutting tool 20 is making a circumferential cut. In one specific embodiment, standoffs 58 are ball bearings (not shown) capable of rotating in any direction.
[0030] As mentioned above, FIG. 1 shows jet cutting tool 20 in its initial or “run-in” position. Each arm 42 is retracted and disposed along housing 22 . After jet cutting tool 20 is properly placed within casing 60 of the well (not shown), cutting fluid 62 ( FIG. 2 ) is pumped down conduit string 10 through passageway 24 of jet cutting tool 20 . Cutting fluid 62 forces piston 26 to move downward, i.e., in the direction of arrow 63 . In so doing, spring 30 is compressed and piston 26 pushes on cam end 48 and rotates arm 42 around or about pivot pin 49 , causing arm 42 to extend outwardly from housing 22 until standoffs 58 of cutting head 50 contact the inner wall surface of casing 60 as illustrated in FIG. 2 . Thus, jet cutting tool 20 is placed in its extended or cutting position.
[0031] After cutting head 50 contacts the inner wall surface of casing 60 , piston 26 can no longer move in the direction of arrow 63 . Therefore, cutting fluid 62 is forced at a greater pressure through tubing 44 to cutting head 50 where it is focused through passage 52 into and through nozzle 56 and out of opening 54 at a high pressure to cut the inner wall of casing 60 as illustrated by cut 64 ( FIG. 2 ). The operator moves conduit string axially to form an axial cut and rotates conduit string 10 to form a circumferential cut. In one specific embodiment (not shown), cutting fluid 62 propels a rotatable cutting member (not shown) to facilitate cutting of the inner wall surface of casing 60 . In other embodiments, all of the cutting is performed by cutting fluid 62 being expelled through nozzle 56 at a high pressure.
[0032] Cutting fluids 62 , and their cutting rates, are known to persons skilled in art. Preferably, cutting fluid 62 is an abrasive cutting fluid such as those having a ratio of 1 pound of abrasive material per gallon of water carrier. Suitable abrasive materials are known in the art such as ground garnet material which is available from many known sources. The water in cutting fluid 62 can be enhanced with polymers to increase the stream holding profile of the cutting fluid 62 to increase cutting efficiency. Typical cutting rates, but by no means the only cutting rates, are expected to be approximately 1 inch per minute using the foregoing cutting fluid 62 .
[0033] After casing 60 has been cut as desired by the operator of jet cutting tool 20 , the operator ceases pumping cutting fluid 62 down conduit string 10 . Accordingly, the force being applied to piston 26 in the direction of arrow 63 ceases. When this occurs, spring 30 expands and, thus, moves piston 26 upward in the opposite direction of arrow 63 . The weight of jet nozzle assembly 40 causes arm 42 to rotate or pivot about cam end 48 until jet nozzle assembly 40 is received within recess 33 of housing 22 . In other words, the removal of the pressure of cutting fluid 62 flowing through passageway 24 of jet cutting tool 20 causes jet cutting tool 20 to return to its run-in position. Subsequently, jet cutting tool 20 can be moved to a new location for additional cutting. Advantageously, the new location can have a smaller diameter and jet cutting tool 20 will properly deploy without the need for removal of jet cutting tool 20 from the well.
[0034] It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. For example, the cutting head is shown as having a rectangular or square shape; however, cutting head can have any shape desired or necessary for providing the type of cut desired by the operator of the jet cutting tool. Likewise, the arm of the jet nozzle assembly and its corresponding recess can have any shape desired or necessary to permit extension and retraction as described above. Moreover, the tubing can be made of any material desired or necessary to facilitate transportation of the cutting fluid from the passageway to the cutting head. Additionally, the size of the opening from the passageway to the tubing, the size of the tubing, the size of the passageway in the cutting head, the size of the nozzle, and the size of the opening in the cutting head can be any size desired or necessary to provide the desired size and depth of cut in the casing. Further, the cutting surface is not limited to casing. Other types of conduits, tubings, or structures may be cut using the jet cutting tools described herein. In addition, spring can be replaced by a pressurized chamber or another device that is biased toward keeping the piston in the retracted position. Alternatively, hydrostatic pressure could provide the force for biasing the piston toward the retracted position by having the passageway in the housing continuing to the end of the jet cutting tool where it is opened to the wellbore. Moreover, the piston may be replaced with a valve or other actuating member known to persons of ordinary skill in the art. Additionally, the tubing may be inflexible and the couplings of the tubing to the housing and the cutting head may be flexible joints providing 360 degree movement. Further, a top sub may be connected to and placed in communication with the passageway of the housing and the tubing may be in fluid communication with the passageway of the housing through a port in the top sub instead of through a port in the housing. Additionally, a ported collar in fluid communication with the tubing may be secured to the exterior of the top sub to place the tubing in fluid communication with the port in the top sub and, thus, in fluid communication with the passageway. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.
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Downhole fluid jet cutting tools having extendible and retractable arms with cutting heads on the ends are disclosed. The jet cutting tools permit casing and other downhole surfaces to be cut utilizing a cutting fluid forced through a jet nozzle assembly. Movement of a piston slidingly engaged within the passageway of the tool actuates the arms when cutting fluid pressure acts on the piston. As a result, the arms are extended and cutting fluid is forced at high pressure from the passageway to the cutting head where it is expelled through nozzles for cutting casing and the like. The jet cutting tools permit the arms to be extended, retracted, and re-extended or redeployed multiple times without the need for being retrieved from the wellbore.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present invention claims priority under 35 USC 119 based on Japanese patent application No. 2004-039613, filed on Feb. 17, 2004. The subject matter of the above-identified priority document is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel injection control system, to a fuel injection control method, and to a fuel injection control apparatus for determining a fuel injection time period in a fuel injection system.
2. Description of the Background Art
Generally speaking, fuel injection systems have been substituted for carburetors in many internal combustion engines, for reasons of improved fuel control precision, cleaner exhaust emissions, better fuel economy and the like. In recent years, fuel injection systems have been adopted in place of carburetors in many motorcycle engines.
A fuel-injected engine generally includes a control device for determining a fuel injection time period in a fuel injection system. The time period is determined based on the engine speed and the throttle position. A fuel-injected engine of this general type is disclosed in Japanese published patent document JP-A 323187/1994.
This conventional control device adjusts fuel injection flow volume in response to engine speed, and specifically, controls an energizing time period to be applied to the fuel injection system, depending on the result of a comparison between the engine speed and a predetermined speed.
In the conventional fuel injection system described above, the fuel injection time period is generally determined by an electronic control unit ECU. However, after the fuel injection time period is determined, a lag time may be required before fuel injection is actually started. Also, although the fuel injection time period is generally determined in response to throttle position, after the fuel injection time period has been determined, the conventional control device has difficulty responding quickly to changing operating conditions.
For example, when the throttle is abruptly opened, the need for fuel rapidly increases, and when the throttle is abruptly closed, the need for fuel rapidly decreases, and conventional systems experience a lag in responding to such changing conditions. This difficulty is particularly acute at low speeds, because when the throttle position is frequently opened and closed, the frequent adjustments occur during an injection interval.
A fuel control system is needed which could respond quickly to changing fuel needs of an engine, under changing operating conditions.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the above-described problems of conventional fuel injection systems, and to provide a fuel injection control apparatus capable of quickly adjusting and supplying the proper amount of fuel under changing operating conditions of a vehicle. The fuel control system hereof provides improved fuel response when the throttle is abruptly opened and the like, as well as improved response to a decrease in a required amount of fuel when the throttle is abruptly closed.
According to a first embodiment of the present invention, a fuel injection control apparatus is provided for determining a base fuel injection time period, based on engine speed and throttle position, in a fuel injection system. The control apparatus determines a base fuel injection time period to start fuel injection operation, based on the engine speed and throttle position.
The control device according to the first embodiment is also operable to adjust the base fuel injection time period, based on changes in engine speed and throttle position within a predetermined time period.
According to the present invention, the response of the fuel injection system to an abrupt change in throttle position is improved. Specifically, after the base fuel injection time period is determined to start fuel injection, if it is necessary to inject more fuel due to the throttle having been abruptly opened and the like, the required fuel can be supplied immediately. Similarly, after the base fuel injection time period is determined to start the fuel injection, if the fuel injection volume required decreases, due to the throttle being abruptly closed or the like, the fuel injection time period is quickly reduced by an appropriate amount, whereby the proper amount of the fuel is supplied to the engine.
When the engine is operating at low speed, it is possible for the control mechanism to determine a second, adjusted fuel injection time period, and based on this determination, to adjust the base fuel injection time period and derive an adjusted fuel injection time period.
When the engine is operating at low speed, the amount of interruption of a pulser or the like is small in an electronic control unit (ECU). Thus, even if the ECU is required to provide an adjusted injection time period after the base injection time period has been determined, a load on the CPU is light, and the control can be executed without placing any excessive load on the ECU.
When the engine is not operating at low speed, the control device does not determine a second, adjusted fuel injection time period, but instead injects fuel based on the base fuel injection time period.
When the engine is operating at a high speed, the amount of interruption of the pulser or the like increases in the electronic control unit ECU. In this case, since the second, adjusted injection time period is not determined, such that the fuel injection is executed in accordance with the base injection time period, the control is still executed without placing any excessive load on the electronic control unit.
Further, when the base fuel injection time period is equal to or less than a predetermined threshold value, the control device only injects the fuel after waiting a predetermined delay period.
Generally, in order to optimize the fuel supply, it is preferable to inject fuel, for example, immediately before an inlet valve for supplying required fuel is opened, using substantially the same timing as intake timing into the engine cylinder.
In the practice of the present invention, since when the first determined, base injection time period is equal to or less than a predetermined value, the injection start timing for injecting the fuel is delayed, it is possible to supply the required fuel at substantially the same timing as intake timing into the engine cylinder.
According to the present invention, it is possible to improve the fuel system response for supplying the proper amount of fuel. Improved fuel system response is required, for example, when the throttle is abruptly opened, or when the throttle is abruptly closed.
For a more complete understanding of the present invention, the reader is referred to the following detailed description section, which should be read in conjunction with the accompanying drawings. Throughout the following detailed description and in the drawings, like numbers refer to like parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side plan view of a motorcycle including a fuel injection system according to the present invention;
FIG. 2 is a top plan view of an isolated motorcycle body frame showing the engine in phantom, with the fuel injection device mounted thereon supported by the body frame;
FIG. 3 is an enlarged side detail view of the motorcycle of FIG. 1 , partially cut away, and showing the engine with the fuel injection device mounted thereon supported by the body frame;
FIG. 4 is a cross-sectional view of the motorcycle engine of FIG. 3 , taken along a medial vertical plane, and showing the fuel injection system mounted thereon;
FIG. 5 is a cross-sectional view of the motorcycle engine of FIG. 3 , viewed in a direction transverse to that of FIG. 3 , and showing the fuel injection system mounted thereon;
FIG. 6 is a schematic block diagram of the electronic control unit (ECU) showing sensor inputs into the ECU as well as connections to the regulator, fuel injector, and ignition;
FIG. 7 is a flow chart showing a process for determination of a base injection time period, and for determination of an adjusted injection time period at low engine speeds;
FIG. 8A is a chart showing injector output over time for a case where the engine is operating at a low speed and the base injection time period is less than the adjusted injection time period;
FIG. 8B is a chart showing injector output over time for the case wherein the engine is operating at a low speed and the first determined injection time period is greater than the adjusted injection time period;
FIG. 9 is a chart showing injector output over time for the case wherein the engine is operating at a high speed;
FIG. 10 is a flow chart showing a process for determination of an injection time period for a second embodiment of the invention;
FIG. 11 is a chart showing injector output over time for the second embodiment of the invention; and
FIG. 12 is a flow chart showing a process for determination of an injection time period for a third embodiment of the invention.
DETAILED DESCRIPTION
Hereinafter, a number of selected illustrative embodiments of the present invention will be described, with reference to the accompanying drawings.
FIGS. 1 and 2 show a trail-type motorcycle M intended for off-road operation. This motorcycle M is provided with a body frame 1 , including a head pipe 2 arranged at the front-end portion thereof. The body frame 1 also includes a pair of main frame sections 3 extending from the head pipe 2 toward the rear of the vehicle body, and extending obliquely downwardly toward the rear, with a space left between the main frame sections 3 in the widthwise direction of the vehicle body. A pair of down tubes 4 extend obliquely downwardly below the main frame sections 3 toward the rear, with a space left therebetween in the widthwise direction of the vehicle body, in a manner similar to, but at a larger angle than, the main frame sections 3 . A coupling portion 5 is provided for coupling the main frame sections 3 to the down tubes 4 .
A front fork 7 is pivotally attached to the head pipe 2 , for supporting a front wheel 6 in a manner so as to enable steering of the motorcycle M. A swing arm or rear fork 10 , for supporting a rear wheel 9 , is pivotally attached to the lower end portions of the main frame sections 3 , so as to allow a reciprocal swinging motion in the up-and-down direction. A rear shock absorber 11 is interposed between the rear fork 10 and the body frame 1 .
A fuel tank 41 is placed between the upper half portions of the main frame sections 3 . A fuel pump 45 is mounted to the fuel tank 41 .
Also, a body cover 43 is provided extending substantially continuously from the fuel tank 41 , and above the lower half portion of the main frame sections 3 . The body cover 43 is formed to have a central portion 43 A which is positioned lower then the respective ends of the body cover 43 , as shown in FIG. 1 .
A single-cylinder four-cycle engine 13 is installed between the main frame sections 3 and the down tubes 4 , so as to be positioned close to an inclined portion of the body frame 1 . The engine 13 is secured to the main frame sections 3 via a plurality of brackets as shown in FIG. 3 , and the underside of the engine 13 is covered with an engine guard 14 . The above-described engine 13 includes a cylinder block 16 , a cylinder 17 and a cylinder head 18 .
Power produced by the engine 13 is transmitted to the rear wheel 9 via a chain transmission system 15 ( FIG. 1 ). An exhaust pipe 19 is connected on the front side of the cylinder head 18 , and the exhaust pipe 19 passes through on the left side of the engine 13 , extends toward the rear of the vehicle body, and is coupled to a muffler 19 A.
A piston 20 is provided in the cylinder 17 in such a manner as to be freely reciprocally slidable therein. As shown in FIGS. 4 and 5 , the piston 20 is coupled to a crankshaft 21 via a connecting rod 23 , and the crankshaft 21 is axially supported on a crankcase 22 .
Also, as shown in FIG. 4 , a throttle body 24 is operatively attached to the backside of the cylinder head 18 . The throttle body 24 has a central axis L 2 oriented so as to intersect an axis L of the cylinder 17 substantially at a right angle. Clean air for combustion is supplied to this throttle body 24 via an air cleaner (not shown).
The throttle body 24 has an idling adjustment screw 25 and a throttle valve 26 . When, for example, the screw 25 is turned to the right during idling adjustment, the throttle valve 26 is incrementally opened, and the amount of air supplied increases to increase the engine speed. When the screw 25 is turned to the left, the throttle valve 26 is incrementally closed, and the amount of air supplied decreases to decrease the engine speed.
The downstream portion of the throttle valve 26 intersects an intake passage 28 of the cylinder head 18 , and an injector (fuel injection system) 31 intersects this intake passage 28 .
The injector 31 is directly installed to the cylinder head 18 such that an axis L 1 of the injector 31 is oriented at a predetermined angle (acute angle) θ, with respect to the central axis L 2 of the throttle body 24 . Also, as seen best in FIG. 1 , the injector 31 is arranged such that the body portion 31 A thereof is substantially completely overlapped by the main frame sections 3 of the motorcycle body 1 , and yet a cap portion 31 B of the injector protrudes above the main frame sections 3 so as to be adjacent to the underside surface of the body cover 43 .
Further, the injector 31 has a connection port 31 C for a fuel tube, and a fuel pump 45 is fluidly connected to this connection port 31 C (See FIG. 1 ). The fuel pump 45 is also attached to the fuel tank 41 , and fuel is supplied via this fuel pump 45 .
The electronic control unit ECU is integrally mounted to the throttle body 24 , and the electronic control unit ECU is also connected to a coupler 31 D of the injector 31 , via a signal cable (not shown).
The crankshaft 21 is mounted on the crankcase 22 , as shown in FIGS. 4 and 5 . The crankshaft 21 is supported on both a roller bearing 114 and a radial ball bearing 115 . In addition to the crankshaft 21 , the crankcase 22 supports a main shaft 33 , a countershaft 34 , a shift drum 35 , a shift spindle 36 and a shift fork 37 . These components constitute a constant-mesh type gear speed change unit (transmission). In this case, a rotating force of the crankshaft 21 is transmitted to the main shaft 33 , or is cut off via a multiple-disc friction clutch 101 shown in FIG. 5 .
The multiple disc clutch 101 is arranged coaxially with the main shaft 33 , and is constructed by having: a clutch outer 102 having clutch disks 102 A; a clutch center 103 having clutch plates 103 A; a pressure plate 104 movable in the axial direction for engaging the clutch by pressing the clutch plates 103 A against the clutch disks 102 A; a plurality of clutch springs 105 for biasing this pressure plate 104 in a clutch engaging direction; and a clutch disengaging mechanism 106 for moving the pressure plate 104 in a clutch disengaging direction.
The clutch disengaging mechanism 106 has a release cylinder 107 . The release cylinder includes a space portion 107 A filled with oil that is connected to the oil cylinder connected to the clutch lever (not shown).
Other related components include a kick shaft 110 ; a cam chain 111 ; a camshaft 112 ; and a rocker shaft 113 .
A gear 108 is affixed to the end of the crankshaft 21 , on the clutch 101 side of the engine. Another gear 109 is affixed to the clutch outer disc 102 of the multiple-disc clutch 101 , and engages this gear 108 . Therefore, when the crankshaft 21 rotates, the clutch outer 102 always rotates via these gears 108 , 109 .
During clutch engagement, the pressure of the oil, with which the space portion 107 A of the release cylinder 107 has been filled, presses the pressure plate 104 in the direction of the left side of the drawing, and a biasing force of the clutch spring 105 presses the clutch center 103 in the direction of the left side of the drawing, whereby the clutch plate 103 A is pressed against the clutch disk 102 A. In this state, a rotating force of the crankshaft 21 , transmitted to the clutch outer 102 via the above-described gears 108 , 109 , is further transmitted to the clutch center 103 via the clutch disk 102 A and the clutch plate 103 A, and is transmitted to the main shaft 33 via this clutch center 103 .
When the clutch has been disengaged by operating the clutch lever (not shown), the oil, with which the space portion 107 A has been filled, escapes on the oil cylinder side connected to the clutch lever. Thereby, the pressure plate 104 moves in the direction of the right side of the drawing, the biasing force of the clutch spring 105 becomes weaker, and a press contact state between the clutch disk 102 A and the clutch plate 103 A is released. When press contact state is released, the clutch center 103 idles to cut off the transmission of power to the main shaft 33 .
The rotating force is transmitted from the crankshaft 21 to the main shaft 33 is transmitted to the counter shaft 34 after its speed is changed into, for example, first speed, second speed or third speed via the gear speed change unit. The rotating force is transmitted to an output shaft (not shown) coupled to the counter shaft 34 via a gear, and is transmitted to the rear wheel 9 from the output shaft via the chain transmission system 15 as power of the engine 13 .
A change pedal (not shown) fitted to the crankcase of the motorcycle is operated to the speed into, for example, first speed, second speed or third speed. Prior to operation of the change pedal, the clutch lever (not shown) is operated to disconnect the crankshaft 21 and the main shaft 33 via the multiple disc clutch 101 . Next, while in the disconnected state, the change pedal is operated. This change pedal is coupled to the shift spindle 36 shown in FIG. 4 . When the change pedal is operated, the shift spindle 36 rotates, and in synchronization therewith, the shift drum 35 rotates via a gear mechanism (not shown). This rotation slides either of the shift forks 37 in the axial direction via a shift pin 37 A engaged with a groove (not shown) of the shift drum 35 . The operated shift fork 37 moves either gear 34 A ( FIG. 5 ) on the counter shaft 34 in the axial direction to engage either gear 33 A ( FIG. 5 ) on the main shaft 33 .
A gear ratio is determined by gears to be engaged each other. The rotating force, transmitted from the crankshaft 21 to the main shaft 33 , is transmitted to the counter shaft 34 after its speed is changed into first speed, second speed or third speed in accordance with its gear ratio via the gear speed change unit. The rotating force is transmitted to an output shaft (not shown) coupled to the counter shaft 34 via a gear; and is transmitted to the rear wheel 9 from the output shaft via the chain transmission system 15 as power of the engine 13 .
The above-described engine is a water-cooled engine. Referring to FIG. 1 , one end of a pair of hoses 51 is connected to a water jacket of the cylinder head 18 . The other end of each hose 51 is connected to a radiator 53 supported between the down tubes 4 . The cooling system includes a radiator fan 55 . Driven by the engine, a water pump (not shown) circulates cooling water, that has cooled the engine via the water jacket, to the radiator 53 . Water cooled within the radiator is then re-circulated to the water jacket.
An alternator 117 ( FIG. 5 ) is coupled to the above-described engine. Two capacitors 62 , 63 are connected to this alternator 117 via a regulator 61 . Each respective capacitor 62 , 63 has a different use. Specifically, one capacitor 62 is connected to a spark plug 118 ( FIG. 5 ) of the engine 13 via an ignition coil 64 . A voltage boosted by an ignition coil 64 is applied to the spark plug 118 . The other capacitor 63 is connected to the above-described injector 31 and fuel pump 45 , and is used for a fuel injection system.
Both capacitors 62 , 63 are provided at the lower end portion of the main frame sections 3 , such that one part overlaps or is flush with the underside of the lower end portion, whereby the layout efficiency is improved. By dividing the capacitor function into two separate capacitors 62 , 63 , the fuel injection system hereof is able to perform control that is substantially unaffected by noise from the ignition coil 64 .
The above-described electronic control unit ECU, as shown in FIG. 6 , is connected to a plurality of sensors, including a negative pressure sensor 41 , a throttle position sensor 42 , an intake temperature sensor 43 , an engine cooling water temperature sensor 44 , and an engine speed sensor (crank angle sensor) 45 . The ECU is also connected with the alternator 117 and a regulator 61 . Further, the above-described injector 31 is connected to the ECU via a signal cable, and the ignition coil 64 and the spark plug 118 are also connected to the ECU.
The above-described engine 13 is a single-cylinder four-cycle engine, and in this case, the electronic control unit ECU determines fuel injection volume every two revolutions (720°) of the crankshaft 21 , transmits the result to the injector 31 , and injects the fuel into the intake passage 28 of the cylinder head 18 only for a time period corresponding to a selected fuel injection volume.
FIG. 7 is a flow chart describing a process for determining a fuel injection time period.
In first step (S 1 ) of this process, the electronic control unit ECU calculates engine speed Ne based on information from the engine speed sensor 45 . In the second step (S 2 ), the ECU reads the throttle position θ from the throttle position sensor 42 . The ECU further reads various other sensor information (for example, information based on the negative pressure sensor 41 , the intake temperature sensor 43 , the engine cooling water temperature sensor 44 and the like) in step (S 3 ).
Thus, based on the engine speed Ne, the throttle position θ, and various additional sensor information, the electronic control unit ECU calculates the fuel injection time period (hereinafter, referred to as the base injection time period) corresponding to the first fuel injection volume to start fuel injection, in accordance with step (S 4 ).
Next, at step (S 5 ), the electronic control unit ECU judges whether or not the engine speed Ne is within a low speed region NC. If the engine speed is within the low speed region NC, at step (S 6 ) the electronic control unit ECU calculates the engine speed Ne again at a predetermined time within a predetermined time period. Note that during this calculation, fuel injection proceeds in accordance with the base injection time period. Then, at step (S 7 ), the ECU reads the throttle position θ. Subsequently, at step (S 8 ), the ECU reads various sensor information. Thus, at step (S 9 ), based on the engine speed Ne, throttle position θ and various sensor information, the electronic control unit ECU calculates a second fuel injection time period (hereinafter referred to as the adjusted injection time period).
The fuel injection time period is generally determined based on the engine speed Ne and the throttle position θ. Since, however, intake air volume of the engine, responsive to the throttle position θ, varies with engine operating conditions, the intake air volume is, in the present structure, determined after the information of the throttle position θ is adjusted based on various sensor information.
Next, based on the adjusted injection time period determined in step (S 9 ), the base injection time period is modified, step (S 10 ). In this adjustment process, the base injection time period determined may be renewed as the adjusted injection time period.
FIG. 8 is a time chart showing adjustment of injector output over time. FIG. 8A shows injector output for a case where the engine is operating at a low speed and the first determined, base injection time period is less than the adjusted injection time period. In this case, at time T 1 , the base injection time period is determined; at time T 2 , a first injection timer is set; and at time T 3 , slightly delayed from setting of the first injection timer, fuel injection by the injector 31 is started. In this case, the base injection time period is from time T 3 to time T 7 .
Next, at a predetermined time, that is, at time T 4 , the adjusted injection time period is determined. At time T 5 , a second injection timer is set. If the adjusted injection time period at this time is from time T 3 to time T 8 , in step (S 10 ) in FIG. 7 , the base injection time period is extended by a time period α. Time period α corresponds to the difference in time of injection periods between the basic and adjusted time periods. In this case, the predetermined time can be set by linking with the crank angle of the crankshaft 21 . Time T 9 is a limit for completion of injection.
Accordingly, even if after the base injection time period is determined and fuel injection is started, it becomes necessary to inject more fuel (for example, due to the throttle position being abruptly opened or for any other reason), it is possible to supply the shortage immediately, and thus it is possible to improve response to rapid changes in fuel supply requirements.
FIG. 8B shows injector output for a case where the engine is operating at a low speed and the first determined, base injection time period is greater than the adjusted injection time period. In this case, at time T 1 , the base injection time period is determined; at time T 2 , a first injection timer is set; and at time T 3 , slightly delayed from time of setting the first injection timer, fuel injection by the injector 31 is started. The base injection time period in this case is from time T 3 to time T 7 .
Next, at a predetermined time, that is, at time T 4 , the adjusted injection time period is determined, and at time T 5 , a second injection timer is set. If the adjusted injection time period at this time is from time T 3 to time T 6 , in step (S 10 ) in FIG. 7 , the base injection time period is shortened by a time period β. The time period β corresponds to the difference in time of injection periods between the base and adjusted time periods. Time T 9 is the limit for completion of injection.
Accordingly, even after the base injection time period is determined and fuel injection is started, if the required fuel injection volume is reduced due to the throttle position being abruptly closed or the like, the system hereof is able to supply the proper amount of fuel, by shortening the injection time period.
The above-described motorcycle is a trail vehicle for a competition, and in this case, particularly when the engine speed is within a low speed region, the throttle position is frequently opened and closed by a rider. In the present embodiment, even for such trail motorcycle, the fuel injection control apparatus sufficiently responds to the rider's operating request.
On the other hand, if at step (S 5 ) in FIG. 7 , it is determined that the engine speed is not within a low speed region NC, that is, when the engine is operating at a high speed, the fuel injection is executed based on the first determined, base injection time period, and such determination and of the adjusted injection time period, as shown in steps S 6 to S 9 , will not be executed.
FIG. 9 is a time chart showing injector output over time for a case where the engine is operating at a high speed. At time T 11 , the base injection time period is determined; at time T 12 , the first injection timer is set; and at time T 13 , which is slightly delayed from time of setting the first injection timer, the fuel injection by the injector 31 is started. The base injection time period is from time T 13 to time T 14 . When the engine speed is within a high speed region, the second, adjusted injection time period is not determined, but instead at time T 14 , the fuel injection by the injector 31 is ended. Time T 15 is the limit for completion of injection.
Accordingly, when the engine speed is operating within a high speed region, the second adjusted injection time period is not determined, and thus a load on the electronic control unit ECU, which is operating under high speed conditions in which an amount of interruption of pulser or the like increases, can be restricted.
FIG. 10 is a flow chart describing a process for determining a fuel injection time period according to a second embodiment of the present invention.
In this case, when the first determined, base fuel injection time period is equal to or less than a predetermined value, the second adjusted injection time period is not determined, and the fuel injection will be executed based on first determined, base fuel injection time period after being delayed by a predetermined time period.
In other words, in FIG. 10 and at step (S 11 ), the electronic control unit ECU calculates engine speed Ne. At step S 12 , the ECU reads throttle position θ, and further at step (S 13 ) reads various sensor information. Thus, at step (S 14 ), based on the engine speed Ne, the throttle position θ and various sensor information, the electronic control unit ECU determines the first base injection time period.
Next, at step (S 15 ), the electronic control unit ECU judges whether or not the first base injection time period is equal to or less than a predetermined value. When the first base injection time period is equal to the predetermined value or less, the process proceeds to step (S 16 ). At step (S 16 ), the start of fuel injection is delayed by a predetermined time period that has been set in advance. Next, at step (S 17 ), fuel injection is started in compliance with the base injection time period, and the injection is executed in accordance with the base injection time period.
However, if at step (S 15 ) the first base injection time period exceeds the predetermined value, the process proceeds to step (S 18 ). At step (Si 8 ), the fuel injection is started in accordance with the first base injection time period. Then, at step (S 19 ), as in the case of the above-described embodiment, the electronic control unit ECU calculates the engine speed Ne, again at a predetermined time within a predetermined time period during fuel injection in compliance with the base injection time period. At step (S 20 ), the ECU reads the throttle position θ, and at step (S 21 ), the ECU reads various sensor information. Further, at step (S 22 ), based on the engine speed Ne, throttle position θ and various sensor information, the electronic control unit ECU determines a second adjusted fuel injection time period. At step (S 23 ), the ECU adjusts the base injection time period determined at step (S 14 ) based on the adjusted injection time period determined in step (S 22 ), in accordance with similar processing to the above-described adjustment processing. In this adjustment processing, the first determined, base injection time period may be renewed by the adjusted injection time period.
FIG. 11 is a chart showing injector output over time for the second embodiment of the invention as illustrated in FIG. 10 . At time T 21 , the base injection time period is determined, and it is judged whether or not the base injection time period is a predetermined value or less.
When the base injection time period is the predetermined value or less, the adjusted injection time period is not determined. Thus, after being delayed for a predetermined time period, at time T 24 , injection in compliance with the base injection time period is started, and at time T 25 , the injection is completed. Time T 26 is the limit for completion of injection. Delay time periods from time T 21 to time T 24 in this case substantially correspond to a total amount of a time period T 22 corresponding to determination of the adjusted injection time period, a time period T 23 corresponding to setting of the injection timer, and a slightly delayed time period T 24 in the above-described embodiment.
In the second embodiment hereof, since when the base injection time period is the predetermined value or less, the fuel injection start is delayed until at least after a time at which the adjusted injection time period should be primarily determined, the fuel can be supplied into the cylinder of the engine 13 at the substantially same timing as intake timing. Therefore, immediately before the inlet valve of the cylinder head 18 is opened, the fuel injection is executed, thereby optimizing the fuel supply.
FIG. 12 is a flow chart showing a process for determination of an injection time period according to a third embodiment of the invention. In the third embodiment, at step (S 25 ), the electronic control unit ECU calculates engine speed Ne. At step (S 26 ), the electronic control unit ECU reads throttle position θ, and further at step (S 27 ), reads various sensor information. Thus, as step (S 28 ), based on the engine speed Ne, the throttle position θ and various sensor information, the electronic control unit ECU determines the first base injection time period.
Next, at step (S 29 ), the electronic control unit ECU judges whether or not the first base injection time period is equal to a predetermined value or less. When the base injection time period is equal to the predetermined value or less, the process is transferred to step (S 30 ). At step (S 30 ) the start of fuel injection is delayed for a predetermined time period that has been set in advance, and then at step (S 31 ) fuel injection in compliance with the base injection time period is started, and the injection is executed in accordance with the base injection time period. Delay time periods in this case can be set to substantially correspond to a total amount of a time period T 22 corresponding to determination of the adjusted injection time period, a time period T 23 corresponding to setting of the injection timer, and a slightly delayed time period T 24 in the above-described embodiment.
When in step (S 29 ), the first base injection time period exceeds the predetermined value, the process is transferred to step (S 31 ). At step (S 31 ), the fuel injection is started in accordance with the first base injection time period without delaying the injection start time.
Accordingly, since when the base injection time period is the predetermined value or less, the injection start is delayed by the predetermined time period, the fuel can be supplied into the cylinder of the engine 13 at the substantially same timing as intake timing. Therefore, immediately before the inlet valve of the cylinder head 18 is opened, the fuel injection is executed, thus optimizing the fuel supply.
Although the description of the present invention has been made herein based on a number of selected illustrative embodiments, the present invention is not limited to the described embodiments. In the adjustment of the base injection time period of the above-described embodiment, the adjusted injection time period is determined, and the base injection time period is adjusted by comparing with the adjusted injection time period. However, the base injection time period may be adjusted by directly comparing, for example, the first and second engine speeds Ne and throttle positions θ without determining the adjusted injection time period. Also, in the above-described embodiments, when completion of the fuel injection exceeds the limit for completion of injection, control for completing this fuel injection is executed before the limit for completion of injection.
While a number of illustrative examples of the present invention have been described above, the present invention is not limited to the working examples described above, but various design alterations may be carried out without departing from the present invention as set forth in the claims.
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A fuel injection control apparatus is capable of supplying a proper amount of fuel by improving response when the throttle position is abruptly changed. The fuel injection control apparatus includes an electronic control unit for determining a fuel injection time period for a fuel injection system, based on the engine speed and the throttle position. The electronic control unit is operable to determine a base fuel injection time period based on engine speed and throttle position to start fuel injection, and adjusts the initial fuel injection time period thereafter, based on changes in the engine speed and the throttle position.
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TECHNICAL FIELD
[0001] The present invention relates to a diagnostic system and more particularly to a small-scale diagnostic system mainly used in a small-scale medical installation.
BACKGROUND
[0002] Conventionally, a diagnostic system is known that when a patient visits the hospital, a technician radiographs the patient to be inspected using an image generating apparatus such as a CR (computed radiography) apparatus or an FPD (flat panel detector), and an image process such as a gradation process is added so as to make the obtained image useable for diagnosis, and the image-processed image is outputted to a doctor for video check.
[0003] In such a diagnostic system, a plurality of persons in charge such as a person in charge (a receptionist) of receiving a patient visited and issuing an inspection order, a person in charge (a technician) of radiographing actually the patient in the radiographing room and generating image data, a person in charge (a technician appointed from general technicians) of judging possibility of offer of the gradated image to diagnosis and when applicable, correcting the contrast and density, and a person in charge of video check (a doctor) of judging (diagnosing) existence of a disease on the basis of the image play their roles, thus the diagnosis progresses.
[0004] And, in a large-scale medical installation in which the conventional diagnostic system is expected to be applied (hereinafter, referred to as a large-scale installation), there are a plurality of image generating apparatuses and technicians for operating them and consoles for operating the image generating apparatuses and viewers by which doctors confirm image data are installed separately so as to respectively play roles. Accordingly, there is a fear that a patient and image data may be mistaken. Therefore, to prevent it, a system for interconnecting each apparatus via a network, issuing an ID in each apparatus, and relating results of the operation process performed by each apparatus to each other is proposed (for example, refer to Patent Document 1).
[0005] In such a system, the places for playing the roles aforementioned are often separated from each other in a wide hospital such that the reception is arranged on the first floor and the radiation department is arranged underground, and in the radiation department, the case that a plurality of technicians execute simultaneously radiography for a plurality of patients using a plurality of radiographic apparatuses is stationary, and a plurality of patients stay always at each process, and to prevent a formed image and each patient from a wrong correspondence, an ID is assigned to each operation at each process, and they are brought into association with each other via a network of an HIS (hospital information system) or an RIS (radiology information system) (for example, refer to Patent Documents 2 and 3).
[0006] For example, the reception on the first floor decides the inspection contents (radiographic contents) on the basis of the main complaint of a patient and enters the contents together with the patient name. By doing this, a patient list as shown in FIG. 12( a ) is formed. The patient list is added whenever necessary and is displayed on the work station for the reception on the first floor. Simultaneously, the patient list, via the network of the RIS or HIS, is displayed on the console (here, the console is referred to as a workstation installed in the radiation department for displaying the setting of radiographing conditions, the radiographing order information of the HIS, and a radiographed image of a patient) of the radiation department in the first basement. Further, the number of consoles installed, to increase the dispersion efficiency, is always more than one, though the consoles are also connected mutually via the network and when a predetermined inspection ID is selected by an optional console, to prevent duplicated radiography between a plurality of technicians, a method for notifying the purport of under processing in the concerned patient list (the flashing display or color is changed or if the same inspection is designated, a warning beep sounds) is used.
[0007] A technician of the radiation department uses the console close to himself, selects the inspection ID to be radiographed hereafter from the patient list displayed, and enters the ID (cassette ID) of the CR plate (cassette) used. By doing this, as shown in FIG. 12( b ), the cassette ID entered in the field of “Cassette ID” of the patient list is displayed. The technician moves to the radiographing room, for example, with three cassettes and radiographs the patient. Thereafter, he reads the photographed cassette by the reading apparatus. The reading apparatus reads the cassette ID attached to the inserted cassette, attaches it to the image data, and transmits the concerned cassette ID, thus finally, the inspection ID (patient ID) is brought into association with the generated image data. The generated image data is transmitted to the console from which the technician selects the inspection ID and is displayed on the console. At this stage, he confirms the radiography positioning, when the positioning is defective, executes again radiography, and judges whether the correction of density and contrast and the frequency emphasizing processing are to be applied or not. Thereafter, he retains the concerned image in the video check waiting (diagnosis waiting) server. The video check doctor extracts and displays the image relating to the predetermined patient from the images preserved in the workstation of the video check room (often having a high-resolution monitor for the viewer function) and the aforementioned video check waiting server and then executes the video check (diagnosis).
[0008] And, in a system used in such a large-scale installation, with respect to the information influencing calculation of insurance points such that, for example, the radiography executed for a patient is simple radiography or contrast medium radiography, by entering the inspection ID and cassette ID of the patient and bringing the patient into association with the radiographic image, all the information is interconnected, is summarized in the RIS or HIS server, thereby can be managed.
[0009] Patent Document 1: U.S. Pat. No. 5,334,851
[0010] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2002-159476
[0011] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2002-311524
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0012] However, according to the investigation of the inventors of the patent application, in a comparatively small-scale medical installation (hereinafter, referred to as a small-scale installation) such as a medical practitioner or a clinic, there are found many cases in which there are very few image generating apparatuses installed, and an assistant positions a patient, and a doctor notified of completion of positioning from the assistant controls the X-ray irradiation switch or a doctor himself performs all operations including positioning of a patient.
[0013] Further, for example, in a large-scale installation, during the period from radiographing to diagnosis by a doctor, it may be supposed that a patient must move back and forth on many floors in the installation, while in a small-scale installation, the installation is narrow, so that during the period from radiographing to diagnosis by a doctor, the movement distance of a patient is short.
[0014] Under such conditions, it may be hardly considered that the radiographic image is mistaken for the patient and if the similar system to that of a large-scale installation is used, an operation of generating inspection order information including input of the patient name is necessary and on the contrary, the procedure is complicated, and the diagnostic efficiency is low.
[0015] Further, to generate beforehand inspection order information of a patient such as patient information and inspection information and bring the concerned inspection order information into association with the radiographic image, a system for connecting the apparatuses to each other with a network corresponding to a basic system such as the HIS or RIS is necessary, though a problem arises that the construction of such a system is expensive and it imposes a burden on a small-scale installation. Further, even if the numbers of respective apparatuses are decreased straight in the constitution concept of the aforementioned large-scale installation, it cannot be said that it is optimum to a small-scale installation.
[0016] On the other hand, if the patient is not brought into association with the radiographic image, for example, when the inspection is executed again for the same patient, the radiographic images of the concerned patient who was radiographed in the past cannot be sought out, and they cannot be used as a comparison image when judging the recovery status, so that a problem arises that the radiographic image cannot be used effectively.
[0017] Further, even in a small-scale installation such as a medical practitioner or a clinic, it is important for improving the diagnostic efficiency that a radiography executor such as a doctor for executing radiography or a radiographing technician can confirm the situation of a patient who stays in the installation and may be radiographed.
[0018] Therefore, the present invention was developed to solve the aforementioned problem and is intended to provide a diagnostic system, in a small-scale installation such as a medical practitioner or a clinic, without increasing the work man-hour such as input of the inspection order information, for offering the situation of a patient who stays in the installation and may be radiographed to a radiography executor and improving the diagnostic efficiency.
Means for Solving the Problems
[0019] To solve the aforementioned problem, the small-scale diagnostic system of the invention stated in claim 1 comprises: a reception registration section to receive and register patient information of a visited patient; a list generation section to generate a list of the patient information which is received and registered by the reception registration section; and an image generating apparatus adapted to generate radiographic image data of an subject region of a patient to be inspected, wherein the image generating apparatus has a display section adapted to display the list of the patient information generated by the list generation section.
[0020] The invention stated in claim 2 , in the invention stated in claim 1 , is characterized in that it comprises: a patient designation section adapted to input a designation of patient information on a patient to be radiographed among the patient information included in the list displayed on the display section; an association section to bring the patient information designated by the patient designation section into association with the radiographic image data formed by the image generating apparatus during a period from a designation of the patient information by the patient designation section to a designation of next patient information; and a storing section to store the radiographic image data and patient information which are brought into association by the association section.
[0021] The invention stated in claim 3 , in the invention stated in claim 1 or 2 , is characterized in that the reception registration section is installed in a computer having a reception information generation section for generating reception related information on the registered patient relating to the accounts and reception.
[0022] The invention stated in claim 4 , in the invention stated in any one of claims 1 to 3 , is characterized in that the list generation section generates a list including at least an order of the reception and registration and patient information, and that the list including at least an order of the reception and registration and patient information is displayed on the display section.
[0023] The invention stated in claim 5 , in the invention stated in any one of claims 1 to 4 , is characterized in that the list generation section, when the patient information is received and registered by the reception registration section or when the generation of reception related information is finished by the reception information generation section, updates the list.
[0024] The invention stated in claim 6 , in the invention stated in any one of claims 1 to 5 , is characterized in that the image generating apparatus is a radiation image reading apparatus.
[0025] The invention stated in claim 7 , in the invention stated in claim 2 , further comprising: a reception information generation section for generating reception related information on the registered patient relating to the accounts and reception, wherein the image generating apparatus is a radiation image reading apparatus which reads radiation image information of a part to be inspected of the patient from a cassette, in which a photostimulable phosphor plate is built-in, used for radiographing of the part to be inspected, the radiation image information is recorded in a photostimulable phosphor plate and generates image data, wherein the radiation image reading apparatus comprises: a detection section to detect mounting of the cassette in the radiation image reading apparatus; a display section; and a notification section, when patient information of a patient to be radiographed is designated by the patient designation section and mounting of the cassette is detected by the detection section, to notify the patient information designated by the patient designation section and the cassette mounting information to the reception information generation section, wherein the reception information generation section, on the basis of the patient information and cassette mounting information notified from the radiation image reading apparatus, generates reception related information relating to the patient corresponding to the notified patient information.
[0026] The invention stated in claim 8 , in the invention stated in claim 7 , is characterized in that the cassette is attached with cassette information relating to the cassette, and the radiation image reading apparatus has a cassette information acquisition section for acquiring the cassette information of the cassette mounted in the radiation image reading apparatus, and the notification section notifies the patient information and the cassette mounting information and also the cassette information acquired by the cassette information acquisition section to the reception information generation section.
[0027] The invention stated in claim 9 , in the invention stated in claim 8 , is characterized in that the cassette information is cassette size information.
[0028] The invention stated in claim 10 , in the invention stated in claim 8 , is characterized in that the cassette information is classification information of the photostimulable phosphor plate built in the cassette.
EFFECTS OF THE INVENTION
[0029] According to the invention stated in claim 1 , using patient information entered by the reception when he visits the hospital, a patient list for radiography is formed automatically and is displayed on the display section of the image generating apparatus. By doing this, to a radiography executor in the radiographing room, the patient information to be radiographed can be provided.
[0030] In this case, in a small-scale installation, a doctor grasping the radiographic contents is mostly a radiography executor, so that there is no need to positively prepare inspection order information. Therefore, there is no need to perform the input operation of the inspection order information by a man in full service which is executed in a conventional large hospital system. Further, a doctor for performing medical examination does not need to perform an unfamiliar input operation by the keyboard. As a result, the diagnostic efficiency will not be lowered.
[0031] Further, the radiography executor, in the radiographing room, can confirm the situation of a patient staying in the installation who may be radiographed, thus the diagnostic efficiency can be improved.
[0032] According to the invention stated in claim 2 , the patient information designated from the patient information list displayed on the display section of the image generating apparatus is automatically brought into association with the radiographic image data radiographed before the next patient information is designated, so that the patient can be brought correctly into association with the radiographic image data, and the physical and spiritual burden imposed on the doctor for preventing the patient and radiographic image data from being mistaken can be lightened, and the diagnostic efficiency can be improved more.
[0033] According to the invention stated in claim 3 , the patient information list can be formed using the computer for generating the reception related information, so that there is no need to provide a special operator as in a large-scale installation and labor saving can be realized.
[0034] According to the invention stated in claim 4 , the radiography executor can confirm the reception and entering procedure and patient information of a patient staying in the installation.
[0035] According to the invention stated in claim 5 , the patient information list is updated in association with a visit of a patient to the hospital and leaving it, so that the radiography executor, in the radiographing room, can confirm the update situation of a patient who stays in the installation and may be radiographed, thus the diagnostic efficiency can be improved.
[0036] According to the invention stated in claim 7 , if the cassette is mounted in the radiation image reading apparatus, the patient information to be radiographed and the cassette mounting information are notified to the reception information generation means, and the reception related information is notified automatically, so that an operator in charge of reception can save his labor of inputting the number of radiographs by viewing paper record cards, and the operation man-hour in the medical installation is reduced, and the processes executed after generation of the reception related information, for example, the processes of accounting and insurance point calculation can be executed earlier, thus the work flow in the installation can be made efficient.
[0037] According to the inventions stated in claims 8 to 10 , if the cassette is mounted in the radiation image reading apparatus, the patient information to be radiographed, cassette mounting information, and cassette information are notified to the reception information generation means, and the reception related information is notified automatically, so that an operator in charge of reception can save his labor of inputting the number of radiographs by viewing paper record cards and cassette information (for example, the cassette size, classification information of the photostimulable phosphor plate, etc.), and the operation man-hour in the medical installation is reduced, and the processes executed after generation of the reception related information, for example, the processes of accounting and insurance point calculation can be executed earlier, thus the work flow in the installation can be made efficient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a drawing showing the entire constitution example of a small-scale diagnostic system 1 relating to the present invention.
[0039] FIG. 2 is a drawing showing an arrangement example of the apparatuses in a medical installation when the small-scale diagnostic system 1 shown in FIG. 1 is applied.
[0040] FIG. 3 is a block diagram of the essential section showing the functional constitution of a reading apparatus 202 applied to the small-scale diagnostic system 1 shown in FIG. 1 .
[0041] FIG. 4 is a block diagram of the essential section showing the functional constitution of a controller 3 applied to the small-scale diagnostic system 1 shown in FIG. 1 .
[0042] FIG. 5 is a block diagram of the essential section showing the functional constitution of a reception computer 5 applied to the small-scale diagnostic system 1 shown in FIG. 1 .
[0043] FIG. 6 is a drawing showing a data storage example of a reception DB 57 shown in FIG. 1 .
[0044] FIG. 7 is a flow chart showing the flow of the processes executed in the small-scale diagnostic system 1 during the period from a visit of a patient to the hospital to leaving it.
[0045] FIG. 8 is a drawing showing an example of a reception input screen 551 displayed on a display section 55 shown in FIG. 5 .
[0046] FIG. 9 is a drawing showing an example of a patient list screen 223 displayed on a display section 221 shown in FIG. 3 .
[0047] FIG. 10 is a drawing showing an example of a radiographic image display screen 351 displayed on a display section 35 shown in FIG. 4 .
[0048] FIG. 11 is a drawing showing an example of the body part icon displayed on the display section 221 shown in FIG. 3 .
[0049] FIG. 12( a ) is a drawing showing an example of a list entered at the reception in a conventional diagnostic system and FIG. 12( b ) is a drawing showing an example when a technician of the radiation department enters a cassette in the list shown in FIG. 12( a ) in the conventional diagnostic system.
DESCRIPTION OF NUMERALS
[0000]
1 Small-scale diagnostic system
2 Image generating apparatus
2 a Ultrasonic diagnostic apparatus
20 Converter
2 b Endoscope apparatus
2 c CR apparatus
201 Radiographic apparatus
202 Reading apparatus
21 CPU
22 Operation-display section
221 Display section
222 Touch panel
223 Patient list screen
23 Communication section
24 RAM
25 Storing section
26 Image generation section
27 Bar code reader
28 Mounting sensor
29 Bus
3 Controller
31 CPU
32 RAM
33 Storing section
331 Temporary storing section
34 Input section
35 Display section
351 Radiographic image display screen
36 Communication section
37 Bus
4 Server
40 Image DB
5 Reception computer
51 CPU
52 RAM
53 Storing section
54 Input section
55 Display section
551 Reception input screen
56 Communication section
57 Reception DB
58 Bus
6 Network
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0093] Hereinafter, an embodiment of the small-scale diagnostic system relating to the present invention will be explained with reference to FIGS. 1 to 11 . However, the present invention is not limited to the illustrations.
[0094] FIG. 1 shows the system constitution of the small-scale diagnostic system 1 of this embodiment and FIG. 2 shows an arrangement example of the apparatuses in a medical installation when the small-scale diagnostic system 1 is applied.
[0095] The small-scale diagnostic system 1 is a system to be applied to a small-scale installation such as a medical practitioner or a clinic, and as shown in FIG. 1 , it is composed of an ultrasonic diagnostic apparatus 2 a which is an image generating apparatus 2 , an endoscope apparatus 2 b , a CR apparatus 2 c , a controller 3 , a server 4 , and a reception computer 5 , and each apparatus, for example, via a switching hub not drawn, is connected to a communication network (hereinafter, referred to as just a “network”) 6 such as a LAN (local area network).
[0096] As a communication system in a hospital installation, generally, the DICOM (Digital Image and Communications in Medicine) standard is used and for communication between apparatuses connected to the LAN, the DICOM MWM (Modality Worklist Management) standard and DICOM MPPS (Modality Performed Procedure Step) standard are used. Further, the communication systems applicable to this embodiment are not limited to the aforementioned.
[0097] For example, a small-scale installation such as a medical practitioner or a clinic, each apparatus is arranged as shown in FIG. 2 .
[0098] Namely, when a patient enters an entrance 10 , there are a reception 11 for receiving him and a waiting room 12 . In the reception 11 , a person in charge of reception is arranged and the person in charge gives a reception No. ticket on which the reception No. (the serial number in the today's reception order) for distinguishing each patient in the reception order is printed to each visited patient. In the reception 11 , the reception computer 5 for executing insurance point calculation and accounting is installed and the person in charge of reception asks the name of a patient and inputs the correspondence of the reception No. to the patient name to the reception computer 5 . Furthermore, the person in charge of reception, on the basis of the record card information after the end of diagnosis of the patient, performs an operation of inputting necessary information of the information relating to the accounts and reception (accounting and insurance point claim calculation) (hereinafter, referred to as reception related information) to the reception computer 5 .
[0099] In the neighborhood of the waiting room 12 , an examination room 13 where a doctor examines and diagnoses a patient is installed across the door. For example, on the examination desk (not drawn) in the examination room 13 , the controller 3 used to display a radiographic image of the patient and make an image diagnosis by the doctor and the server 4 having an image DB (data base) 40 for storing image data of the radiographic image are arranged. In the examination room 13 , the ultrasonic diagnostic apparatus 2 a which is little necessary to be operated in an isolated zone from the viewpoint of privacy is installed.
[0100] Further, on the opposite side of the examination room 13 across a passageway 14 , an X-ray radiographic room 15 for executing X-ray radiography is installed. In the X-ray radiographic room 15 , the CR apparatus 2 c composed of a radiographic apparatus 201 and a reading apparatus 202 is arranged. Furthermore, in the neighborhood of the X-ray radiographic room 15 , an inspection room 16 is installed and the endoscope apparatus 2 b is arranged in the inspection room 16 .
[0101] Hereinafter, the small-scale diagnostic system 1 will be explained in detail.
[0102] Firstly, the constitution of each apparatus will be explained.
[0103] The image generating apparatus 2 is a modality, for example, for radiographing the inspected part of a patient as a subject by the ultrasonic diagnostic apparatus 2 a , endoscope apparatus 2 b , and CR apparatus 2 c , converting the radiographed image to digital, thereby generating image data of the radiographic image.
[0104] The ultrasonic diagnostic apparatus 2 a is composed of an ultrasonic probe for outputting ultrasonic waves and an electronic device connected to the ultrasonic probe for converting acoustic waves (an echo signal) received by the ultrasonic probe to image data of a radiographic image of the internal tissue (both are not drawn). The ultrasonic diagnostic apparatus 2 a sends acoustic waves into the body from the ultrasonic probe, receives again the acoustic waves (an echo signal) reflected from the intra-body tissue by the ultrasonic probe, and generates a radiographic image corresponding to the echo signal by the electronic device.
[0105] To the ultrasonic diagnostic apparatus 2 a , a converter 20 which is a converting means for converting an analog signal to a digital signal is connected and the ultrasonic diagnostic apparatus 2 a is connected to a network 6 via the converter 20 . Via the converter 20 like this, even when data of a form not conforming to the standard (for example, a communication protocol) of another external device connected to the network 6 is outputted from the ultrasonic diagnostic apparatus 2 a , by appropriate conversion, data can be transmitted or received between itself and the external device connected to the network 6 .
[0106] The endoscope apparatus 2 b is an apparatus in which a small radiographic apparatus is installed at the leading edge of a flexible tube (both are not drawn) and the radiographic apparatus includes, for example, an objective optical system composed of an optical lens, a radiographing section arranged at the imaging position of the objective optical system, and a lighting section composed of an LED (light emitting diode) for lighting for radiographing (these are all not drawn). The radiographing section includes, for example, a solid-state radiographic device such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor), which if light enters, converts photoelectrically it to an electric signal according to the incident light quantity of the light. The objective optical system is structured so as to collect light from the region lighted by the lighting section by the optical lens and form an image on the solid-state radiographic device of the radiographing section, and the light entering the solid-state radiographic device is converted photoelectrically, thus the image data of the radiographic image is outputted as an electric signal.
[0107] The CR apparatus 2 c is an apparatus for executing radiography for a subject using a photostimulable phosphor plate, storing radiation energy transmitting the subject in the photostimulable phosphor plate, reading an image stored in the photostimulable phosphor plate, thereby generating image data of the radiographic image. In the CR apparatus 2 c , the reading apparatus (the radiation image reading apparatus) has a radiation source and contains the photostimulable phosphor plate and there are a type of executing from radiographing to reading using one apparatus and a type using a portable cassette for storing a photostimulable phosphor plate available. In this embodiment, the cassette-type CR apparatus is illustrated, though the present invention is not limited to it.
[0108] The CR apparatus 2 c is composed of the radiographic apparatus 201 having a radiation source and the reading apparatus 202 for reading an image from the photostimulable phosphor plate stored in the cassette used for radiation in the radiographic apparatus 201 and generating radiographic image data (refer to FIG. 2 ). Further, to the cassette, a bar code indicating the cassette information is attached. The cassette information is information indicating the attribute of the concerned cassette and concretely, it includes the cassette information indicating the size of the concerned cassette and the information (plate classification information) indicating the classification of the photostimulable phosphor plate built in the cassette. The plate classification information is information indicating whether it is a plate used for mammography radiography which is added to the insurance points or a plate used for radiography of the other parts.
[0109] FIG. 3 is a block diagram showing the functional constitution of the reading apparatus 202 . As shown in FIG. 3 , the reading apparatus 202 includes a CPU 21 , an operation display section 22 , a communication section 23 , a RAM 24 , a storing section 25 , an image generation section 26 , a bar code reader 27 , and a mounting sensor 28 and the respective sections are connected to each other with a bus 29 .
[0110] The CPU 21 reads the control program stored in the storing section 25 , stores it in the work area formed in the RAM 24 , and controls each section of the reading apparatus 202 according to the control program. Further, the CPU 21 , according to the control program, reads various processing programs stored in the storing section 25 , stores them in the work area, and in cooperation with the read programs, executes various processes including the process of the reading apparatus 202 shown in FIG. 7 . The CPU 21 functions as a communication means of the present invention.
[0111] The operation display section 22 is composed of a display section 221 and a touch panel 222 . The display section 221 is composed of a display screen composed of a LCD (liquid crystal display) and according to an instruction of a display signal inputted from the CPU 21 , displays a patient list on the display screen.
[0112] The touch panel 222 is installed so as to cover the top of the display section 221 , detects a desired input position inputted by an operation of a user using his finger, and outputs the detection signal to the CPU 21 . The touch panel 222 functions as a patient designation means of the present invention.
[0113] The communication section 23 is composed of a network interface and transfers data with an external device connected to the network 6 .
[0114] The RAM 24 , in various processes executed and controlled by the CPU 21 , forms a work area for temporarily storing various programs which are read from the storing section 25 and can be executed by the CPU 21 , input or output data, and parameters.
[0115] The storing section 25 is composed of a nonvolatile semiconductor memory and stores the control program executed by the CPU 21 , various programs, and various data.
[0116] The image generation section 26 is structured so as to mount the cassette used for radiography, fetches the photostimulable phosphor plate from the mounted cassette, scans it with exciting light, emits stimulated light from the radiation image information stored in the photostimulable phosphor plate, and on the basis of an image signal obtained by photoelectrically reading the stimulated light emitted, generates image data.
[0117] The bar code reader 27 reads the bar code displayed on the cassette and outputs it to the CPU 21 .
[0118] The mounting sensor 28 detects existence of mounting of the cassette into the image generation section 26 and outputs the detection signal to the CPU 21 .
[0119] The controller 3 is installed, for example, in the examination room 13 , and it is a work station where the image data transmitted from the image generating apparatus 26 and patient information are brought into association with each other and a doctor displays an image and makes a video check diagnosis, and it may include a higher-resolution monitor than a monitor used in the general PC (personal computer).
[0120] FIG. 4 is a block diagram showing the functional constitution of the controller 3 . As shown in FIG. 4 , the controller 3 is composed of a CPU 31 , a RAM 32 , a storing section 33 , an input section 34 , a display section 35 , and a communication 36 and the respective sections are connected to each other with a bus 37 .
[0121] The CPU 31 reads various programs such as the system program and processing programs stored in the storing section 33 , stores them in the RAM 32 , and according to the stored programs, executes various processes including the process of the controller 3 shown in FIG. 7 . The CPU 31 functions as a corresponding means of the present invention.
[0122] The RAM 32 , in various processes executed and controlled by the CPU 31 , forms a work area for temporarily storing various programs which are read from the storing section 33 and can be executed by the CPU 31 , input or output data, and parameters. For example, the RAM 32 forms a patient information region for storing temporarily patient information received from the reading apparatus 202 .
[0123] The storing section 33 is composed of an HDD (hard disc) or a nonvolatile memory of a semiconductor. In the storing section 33 , the system program executed by the CPU 31 and various programs are stored and as disclosed in the specifications of Japanese Unexamined Patent Application Publication No. 11-85950 and Japanese Unexamined Patent Application Publication No. 2001-76141, the part discrimination parameters (a lookup table for bringing the contour and shape to be radiographed appearing in a radiographic image into association with the radiographing part, etc.) for discriminating the radiographing part and the image processing parameters (a lookup table for defining the gradation curve used for the gradation process, the emphasizing degree of the frequency process, etc.) for performing the image processing according to the radiographing part discriminated are stored.
[0124] Further, the storing section 33 has a temporary storing section 331 for temporarily storing the image data transmitted from the image generating apparatus 2 . The storing section 33 functions as a storing means of the present invention.
[0125] The input section 34 is composed of a keyboard including a cursor key, numeral input keys, and various function keys and a pointing device such as a mouse and outputs a pressing signal of a key operated from the keyboard and an operation signal by the mouse to the CPU 31 as an input signal.
[0126] The display section 35 is composed of, for example, monitors of a CRT (cathode ray tube) and an LCD (liquid crystal display) and according to an instruction of a display signal inputted from the CPU 31 , displays various screens.
[0127] The communication section 36 is composed of a network interface and transfers data with an external device connected to the network 6 via a switching hub.
[0128] Again in FIG. 1 , the server 4 is a computer composed of a storing section composed of a CPU, a RAM, and an HDD and a communication section for controlling communication with each apparatus connected to the network 6 (both are not drawn). The server 4 has an image DB 40 and by the software process in cooperation with the programs stored in the CPU and storing section, brings the image data of the radiographic image which is instructed to be written from the controller 3 via the communication section into association with the supplementary information thereof (the information including the patient information), and then stores them in the image DB 40 as an image storing means and in compliance with the request from the controller 3 , searches the image DB 40 , reads the image data according to the request and supplementary information thereof, and transmits them to the controller 3 .
[0129] The reception computer 5 is a computer for receiving and entering a patient visiting the hospital and executing accounting and insurance point calculation.
[0130] FIG. 5 is a block diagram showing the functional constitution of the reception computer 5 . As shown in FIG. 5 , the reception computer 5 is composed of a CPU 51 , a RAM 52 , a storing section 53 , an input section 54 , a display section 55 , a communication section 56 , and a reception DB 57 and the respective sections are connected to each other with a bus 58 .
[0131] The CPU 51 reads various programs such as the system program and processing programs stored in the storing section 53 , stores them in the RAM 52 , and according to the stored programs, executes various processes including the process of the reception computer 5 shown in FIG. 7 . The CPU 51 functions as a reception-entering means, a list forming means, and reception information generation means of the present invention.
[0132] The storing section 53 is composed of an HDD (hard disc) or a nonvolatile memory of a semiconductor and stores the system program executed by the CPU 51 , various processing programs, and various data.
[0133] The input section 54 is composed of a keyboard including a cursor key, numeral input keys, and various function keys and a pointing device such as a mouse and outputs a pressing signal of a key operated from the keyboard and an operation signal by the mouse to the CPU 51 as an input signal.
[0134] The display section 55 is composed of, for example, monitors of a CRT and an LCD and according to an instruction of a display signal inputted from the CPU 51 , displays various screens.
[0135] The communication section 56 is composed of a network interface and transfers data with an external device connected to the network 6 via a switching hub.
[0136] The reception DB 57 is a data base for bringing the reception related information relating to a visited patient into association with the patient information and storing it. FIG. 6 shows a data storage example of the reception DB 57 . The reception DB 57 is a data base for storing reception related information of each patient visiting the hospital and as shown in FIG. 6 , it includes a “Reception Date” item 57 a for storing the reception data of a patient, a “Reception No.” item 57 b for storing the reception No. given to the patient, a “Patient Information” item 57 c for storing the patient information (here, it is described as patient name), a “No. of radiographs” item 57 d for storing the number of images radiographed for the patient on the reception date, a “No. of contrast medium images” item 57 e for storing the number of radiographs using a contrast medium, a “Modality” item 57 f for storing the kind of the image generating apparatus 2 executing radiography, a “Part” item 57 g for storing the information on the radiographing part, a “Plate Kind” item 57 h for storing the plate classification information used for radiography, a “Cassette Size” item 57 i for storing the size information of the cassette used for radiography, a “Medication” item 57 j for storing the medication information prescribed for the patient on the reception date, a “Name of Injury or Disease” item 57 k for storing the name of injury or disease diagnosed by a doctor on the reception date, a “Comments” item 57 l for storing comments inputted from the controller 3 which will be described later, and an “Insurance Points” item 57 m for storing the insurance points calculated.
[0137] Next the operation of the small-scale diagnostic system will be explained.
[0138] FIG. 7 is a flow chart showing the flow of the processes executed in the small-scale diagnostic system 1 during the period from a visit of a patient to the hospital to leaving it. Hereinafter, by referring to FIG. 7 , the flow of a series of processes in the small-scale diagnostic system during the period from a visit of a patient to the hospital to leaving it will be explained together with the work flow of the intra-installation staff (doctor, radiographing technician, person in charge of reception).
[0139] Firstly, at the reception 11 , by the person in charge of reception, a reception No. ticket is given to the visited patient and the patient name is asked. Next, he operates the input section 54 of the reception computer 5 to display a reception input screen 551 (refer to FIG. 8 ), and the reception No. is input into a reception No. field 551 a by the input section 54 , and the patient name which is patient information is input into a patient name field 551 b.
[0140] In the reception computer 5 , if a display instruction of the reception input screen 551 is input from the input section 54 , on the display section 55 , the reception input screen 551 on which the reception No. field 551 a and patient name field 551 b for inputting the reception No. and patient information are provided is displayed, and if the patient information such as the reception No. and patient name is input into the reception No. field 551 a and patient name field 551 b by the input section 54 via the reception input screen 551 (Step S 1 ), a new record is added to the reception DB 57 , and the present date is written into the “Reception Date” item 57 a , and the inputted reception No. is written into the “Reception No.” item 57 b , and the input patient information is written into the “Patient Information” item 57 c , and they are received and entered (Step S 2 ). FIG. 8 shows an example of the reception input screen 551 .
[0141] In the reception computer 5 , if the patient is received and entered, patient list information of the patient received and entered is generated (or updated) (Step S 3 ). The patient list information, for example, is generated if the first patient is received and entered, is stored in a predetermined region of the RAM 52 , and is updated to new patient list information whenever the next patient is received and entered. The patient list information, for example, if a record that the present date is stored in the “Reception Date” item 57 a from the reception DB 57 and no data is stored in the items other than the “Reception Date” item 57 a , the “Reception No.” item 57 b , and the “Patient Information” item 57 c is extracted, is generated on the basis of the extracted record. The patient list information includes at least the patient information such as the reception No. indicating the reception order and patient name. The patient list information generated or updated is transmitted to the reading apparatus 202 via the communication section 56 (Step S 4 ). In the reading apparatus 202 , if the patient list information is received via the communication section 23 , on the basis of the patient list information received, the patient list screen 223 is displayed on the display section 221 (Step S 5 ).
[0142] The patient given the reception No. stands by in the waiting room 12 and then moves to the examination room 13 . In the examination room 13 , the doctor conducts a medical examination to the patient and the radiography (the kind of the image generating apparatus 2 , radiographing part, radiographing direction, number of radiographs, etc.) to be executed for the concerned patient is decided. The patient, by an instruction of the radiography executor for executing radiography such as a doctor or a radiographing technician, moves in front of the image generating apparatus 2 (the ultrasonic diagnostic apparatus 2 a , endoscope apparatus 2 b , or CR apparatus 2 c ) for executing radiography.
[0143] The radiography executor, after the patient moves on the front of the image generating apparatus 2 for executing radiography, moves on the front of the reading apparatus 202 and designates the patient information to be radiographed from the patient list screen 223 displayed on the display section 221 .
[0144] FIGS. 9( a ) and 9 ( b ) show examples of the patient list screen 223 . The patient list screen 223 displays the patient information list of a patient and receives designation of the patient information of the patient to be radiographed from the patient list.
[0145] FIG. 9( a ) is a patient list screen as an aspect of displaying the reception No. and patient name of each patient from the top information of the patient list information. On the patient list screen 223 , upon receipt of the patient list information, the top information is displayed first and if the “Skip” button is touched, the next information in the patient list information is displayed. If the screen is touched when the patient information of the patient to be radiographed is displayed, the displayed patient information is designated as patient information of the patient to be radiographed. The display of the patient list screen 223 shown in FIG. 9( a ), when the screen of the display section 221 is small, can be changed so as to see easily the patient list.
[0146] FIG. 9( b ) is a patient list screen including the reception No. field 223 a and patient name field 223 b as an aspect of listing the patient list information. It is selected by touching the patient information of the patient to be radiographed and if the “Selection” button is touched furthermore, the selected patient information is designated as patient information of the patient to be radiographed. The patient list screen 223 shown in FIG. 9( b ), when the screen of the display section 221 is large, can display the patient list so as to be seen easily. Further, when the screen of the display section 221 is small, the display region of each patient information is small, so that the patient information can be hardly selected by the touch panel. Therefore, if a ten-key pad is installed separately instead of the touch panel 222 , and the patient list is referred to, and a search ID (here, the reception No.) corresponding to the patient information designated as a radiographic subject is input via the ten-key pad, an aspect that the patient information corresponding the search ID is designated as patient information to be radiographed may be used.
[0147] If the list screen, as shown in FIGS. 9( a ) and 9 ( b ), of a patient who is received and entered and does not leave yet the hospital, that is, a patient staying the installation is displayed on the reading apparatus 202 in the radiographing room 15 , the radiography executor can easily confirm and grasp the update situation of the patient staying in the installation, and the diagnostic efficiency can be improved.
[0148] In the reading apparatus 202 , if the patient information is designated from the patient list screen 223 by the touch panel 222 (Step S 6 ), the designated patient information is transmitted to the controller 3 via the communication section 23 (Step S 7 ). In the controller 3 , upon receipt of the patient information from the reading apparatus 202 , the received patient information is stored (overwritten and held) in the patient information region of the RAM 32 (Step S 8 ).
[0149] If the designation of the patient information is finished, the radiography executor moves to the image generating apparatus 2 for executing radiography, radiographs the inspected part of the patient as a subject, and generates image of data of the radiographic image. When the image generating apparatus 2 for executing radiography is the CR apparatus 2 c , the radiographic apparatus 201 executes radiography and mounts the radiographed cassette in the reading apparatus 202 . In the reading apparatus 202 , if the mounting of the radiographed cassette is detected by the mounting sensor 28 as a detection means (YES at Step S 9 ), the bar code attached to the cassette is read by the bar code reader 27 as a cassette information acquisition means, and the cassette information is acquired (Step S 10 ), and the cassette mounting notification, the patient information designated at present from the patient list screen, and the acquired cassette information are transmitted to the reception computer 5 via the communication section 23 (Step S 11 ). Next, by the image generation section 26 , the radiation image recorded on the mounted cassette is read and image data is generated (Step S 12 ) and is transmitted to the controller 3 via the communication section 23 (Step S 13 ). Further, it is preferable to supplement the patient information of the patient as a subject, that is, the patient information designated at Step S 7 to the generated image data as supplementary information and transmit it to the controller 3 . When a patient is radiographed several times under a plurality of radiographic conditions, Steps S 9 to S 13 are executed repeatedly.
[0150] In the reception computer 5 , if the cassette mounting notification, patient information, and cassette information from the reading apparatus 202 are received by the communication section 56 , on the basis of the received information, reception related information is generated (Step S 14 ). Concretely, in the reception DB 57 , the reception date is today, and a record having the received patient information is searched, and the “Number of Radiographs” item 57 d of the record is counted up by 1, and the information indicating the CR apparatus is written into the “Modality” item 57 f , and the plate classification information included in the cassette information is written into the “Plate Kind” item 57 h , and the cassette size information included in the cassette information is written into the “Cassette Size” item 57 i.
[0151] When the image generating apparatus 2 for executing radiography is other than the CR apparatus 2 c , that is, when it is the ultrasonic diagnostic apparatus 2 a or the endoscope apparatus 2 b , if radiography is instructed from the input section (YES at Step S 15 ), the radiography is executed by the radiography executor (Step S 16 ) and the image data obtained by the radiography is transmitted to the controller 3 (Step S 17 ). Further, when a patient is radiographed several times under a plurality of radiographic conditions, all the image data generated is transmitted to the controller 3 .
[0152] In the controller 3 , if image data is received from the reading apparatus 202 or the image generating apparatus 2 , the received image data is brought into association with the patient information stored in the patient information region of the RAM 32 and is stored in the temporary storing section 331 (Step S 18 ). Namely, in the controller 3 , the patient information is designated by the reading apparatus 202 and during the period from reception of the designated patient information by the controller 3 to designation of the next patient information from the reading apparatus 202 , the image data received from the reading apparatus 202 or the image generating apparatus 2 is brought into association with the patient information designated by the reading apparatus 202 and is stored. Further, if only one patient is always radiographed (when there are not a plurality of patients in the radiographing room), if the patient information is transmitted from the reading apparatus 202 to the controller 3 , image data of the ultrasonic diagnostic apparatus 2 a or endoscope apparatus 2 b which is generated before the next patient information is transmitted can be brought into association with the patient information by the controller 3 .
[0153] If the radiography is finished, the patient moves to the examination room 13 . The doctor operates the input section 34 of the controller 3 to display an image searching screen not drawn on the display section 35 and inputs the patient information of the objective patient. The controller 3 displays the image searching screen according to the operation of the input section 34 and receives input of the patient information via the input section 34 . If the image searching screen is displayed and the patient information is input from the screen via the input section 34 (Step S 19 ), the image data corresponding to the input patient is extracted from the temporary storing section 331 , and the image process such as the gradation process or frequency emphasizing process is performed for the extracted image data, and a thumbnail image which is image-processed image data contracted is prepared and is displayed on a radiographic image display screen 351 of the display section 35 (Step S 20 ).
[0154] FIG. 10 shows a display screen example of the radiographic image display screen 351 displayed on the display section 35 . As shown in FIG. 10 , the radiographic image display screen 351 has image display fields 351 a to 351 d for listing the extracted images. If any of the image display fields 351 a to 351 d is selected by the mouse of the input section 34 , the selected image is displayed independently in the life size. The doctor, from the independently displayed image, observes the image in detail and can make a video check diagnosis. Further, on the upper right of the screen, an image process adjustment field 351 e is provided, and the doctor operates the image process adjustment field 351 e by the mouse, thereby can adjust the density and contrast. If an OK button 351 h displayed in correspondence with each image is pressed, the displayed image can be decided as an image to be stored in the image DB 40 . Further, on the radiographic image display screen 351 , a patient information display field 351 f for displaying the patient information corresponding to the displayed radiographic image is provided.
[0155] After the image process adjustment and image decision are executed from the radiographic image display screen 351 via the input section 34 (Step S 21 ), if the End button of the radiographic image display screen 351 is pressed by the input section 34 and the end of diagnosis is instructed (YES at Step S 22 ), the image data corresponding the patient information of the concerned patient is transmitted to the server 4 via the communication section 36 and is stored in the image DB 40 (Step S 23 ). The image data written into the image DB 40 of the server 4 is erased from the temporary storing section 331 (Step S 24 ).
[0156] If the examination of the patient is finished in the examination room, the patient moves to the reception 11 and the account is settled. The doctor records his opinion (the name of injury or disease examined) on the concerned patient, the medication information indicating the medicine prescribed for the patient, and the information relating to the radiography executed for the patient (the apparatus kind executing radiography, the number of radiographs, existence of a contrast medium, the radiographing part, the radiographing direction, etc.) on a paper record card. And, he sends the paper record card to the reception 11 .
[0157] The person in charge of reception displays the reception related information input screen (not drawn) on the reception computer 5 and from the reception related information input screen, on the basis of the description of the paper record card, inputs the reception No. and reception related information of the objective patient. Here, when radiography is executed by the CR apparatus 2 c , the modality classification, the number of radiographs by the CR apparatus 2 c , the plate kind, and the cassette size information are entered already, and the person in charge of reception does not need to input these information, so that the input operation is simplified and the account can be settled earlier.
[0158] On the reception computer 5 , the information inputted from the reception related information input screen is added, entered, and stored in the corresponding item of the record of the reception DB 57 having the reception No. of the objective patient (Step S 25 ). Further, on the basis of the input reception related information, the accounting information-insurance point calculation process for the patient is performed (Step S 26 ). The person in charge of reception, on the basis of the calculated accounting information, charges the patient the fee for medical examination and settles the account. The patient pays the accounts and leaves the hospital.
[0159] On the reception computer 5 , if the accounting information-insurance point calculation process is finished, it is judged that the patient leaves the hospital, and from the patient list information stored in the RAM 52 , the reception related information is entered, and the patient information which is an object of accounting information-insurance point calculation is deleted and updated (Step S 27 ), and the updated patient list information is transmitted to the reading apparatus 202 via the communication section 56 (Step S 28 ). On the reading apparatus 202 , for the next radiography, on the basis of the updated patient list information, the patient list screen is displayed (Step S 29 ).
[0160] As explained above, according to the small-scale diagnostic system 1 , on the reception computer 5 , if visited patients are received and entered, a patient information list of the patients visited today is generated and the patient list screen is displayed on the display section 221 of the reading apparatus 202 . If the patient information of the patient to be radiographed is designated from the patient list screen of the reading apparatus 202 , the concerned designated patient information is transmitted to the controller 3 and is stored in the patient information region of the RAM 32 of the controller 3 . In the image generating apparatus 2 , if the patient is radiographed and image data is generated, the generated image data is transmitted to the controller 3 . On the controller 3 , if the image data is received, the image data is brought into association with the patient information stored in the patient information region of the RAM 32 , is stored in the temporary storing section 331 , is used for diagnosis of the doctor, and then is stored in the image DB 40 of the image server 4 .
[0161] Therefore, using the information, on the reception computer 5 , received and entered when a patient visits the hospital, patient list information for radiographing is generated automatically and is displayed on the display section 221 of the reading apparatus 202 . By doing this, in the radiographing room, the patient information to be radiographed can be provided for the radiography executor.
[0162] In this case, in a small-scale installation, a doctor grasping the radiographic contents is mostly a radiography executor, so that there is no need to positively prepare inspection order information. Therefore, there is not need to perform the input operation of the inspection order information by a man in full service which is performed in a conventional large hospital system. Further, a doctor for performing medical examination does not need to perform an unfamiliar input operation by the keyboard. As a result, the diagnostic efficiency will not be lowered.
[0163] Further, the radiography executor, in the radiographing room, can confirm the update situation of a patient staying in the installation, thus the diagnostic efficiency can be improved.
[0164] Furthermore, if the patient information to be radiographed is designated from the patient list screen displayed on the display section 221 , all the image data generated by the reading apparatus 202 and image generating apparatus 2 before the next different patient information is designated, in the controller 3 , is automatically brought into association with the designated patient information, so that in the small-scale installation, the patient can be brought correctly into association with the image, and the physical and spiritual burden imposed on the doctor for preventing the patient and radiographic image from being mistaken can be lightened, and the diagnostic efficiency can be improved more.
[0165] Further, according to the small-scale diagnostic system 1 , if the patient information of the patient to be radiographed is designated from the patient list screen of the reading apparatus 202 and the cassette is mounted, the bar code attached to the cassette is read, and the cassette information (the plate classification information and cassette size information) indicated by the bar code is acquired, and the acquired information is transmitted to the reception computer 5 together with the cassette mounting notification and designated patient information. In the reception computer 5 , on the basis of the information received from the reading apparatus 202 , plate related information for the designated patient is generated.
[0166] Therefore, at the time of radiography by the CR apparatus, the number of radiographs, plate classification information, and cassette size information which are necessary as reception related information are automatically notified the reception computer 5 , and reception related information is generated automatically in the reception computer 5 , so that the person in charge of reception can save his labor of looking at the paper record card and inputting these information, thus an input error is prevented, and the operation man-hour is reduced, and the processes executed after generation of the reception related information, for example, the processes of accounting and insurance point calculation can be executed earlier. As a result, the entire work flow in the installation can be made efficient.
[0167] Further, the description contents of the embodiment aforementioned are a preferable example of the small-scale diagnostic system 1 relating to the present invention and the present invention is not limited to it.
[0168] For example, in the aforementioned embodiment, on the reception computer 5 , if the reception and leaving of the patient are entered, the patient list information is updated, and the updated patient list information is transmitted to the reading apparatus 202 , thus the patient list screen of the patient staying at present in the installation is displayed on the reading apparatus 202 , though when the patient is received and entered, the information relating to the added patient (for example, the reception No. and patient information, etc.) is transmitted from the reception computer 5 to the reading apparatus 202 and is added to the patient list screen of the display section 221 , and when the patient is entered leaving the hospital, the information on the left patient (for example, the reception No. and patient information, etc.) is transmitted from the reception computer 5 to the reading apparatus 202 and may be deleted from the patient list screen of the display section 221 . Further, a terminal used to input check-in and check-out by a patient is installed at the reception 11 and the input information (entering and leaving information) from the terminal is transmitted to the reading apparatus 202 , and on the reading apparatus 202 , the patient list screen of the patient staying at present in the installation may be displayed.
[0169] Further, the system, in correspondence with each patient information on the reception input screen, is structured so as to display a check field or an icon for designating a patient whose information is not added to the patient list, thus the person in charge of reception, when a patient visiting the hospital, for example, comes only to receive medicine or when he judges that no radiography is necessary from the latest name of injury or disease of the patient, at the time of reception and entering of the patient, may designate and input not to add him to the patient list, and the reception computer 5 may exclude the concerned designated patient information and generate a patient list. Further, it is possible to exclude the reception No. and display only the patient information as a patient list.
[0170] Further, in the aforementioned embodiment, the bar code indicating the cassette size information and the plate classification information showing whether it is mammographic radiography or not is attached to the cassette and is read by the bar code reader in the reading apparatus 202 , thus the cassette size information and plate classification information are acquired, though in the reading apparatus 202 , it is possible to analyze the generated image data, for example, generate a histogram of image data, and obtain the maximum and minimum values, thereby acquire the information on whether it is mammographic radiography or not.
[0171] Further, in the reading apparatus 202 , when the cassette is mounted, it is possible to display, for example, a body part icon for selecting each part of the human body as shown in FIG. 11 on the display section 221 , acquire the radiographing part information touched (selected) from the body part icon, and transmit the acquired radiographing part information to the reception computer 5 together with the cassette mounting notification, patient information, and cassette information. By doing this, the information on the radiographing part of the reception related information is generated automatically, and the person in charge of reception does not need to input it, and the work flow in the installation can be made more efficient.
[0172] Further, in the aforementioned embodiment, the CR apparatus is illustrated as a radiation image generating apparatus, though the FPD can be used as a radiation image generating apparatus. When using the FPD, disclosed in Japanese Unexamined Patent Application Publication No. 2000-131785, having a display section (including an external device) and an operation section, the patient list is displayed on the display section and the patient information to be radiographed can be selected from the patient list by the operation section. In this case, the selected patient information can be transmitted to the controller 3 or the reception computer 5 wirelessly or through wire.
[0173] Further, in the FPD, since it is expensive, the cassette is changed little according to the radiographing part unlike the CR cassette and a plurality of radiographic image data is stored generally in one cassette. At this time, the execution of radiography can be recognized on the basis of a trigger signal of the reading operation or reset operation, so that each of the plurality of radiographic image data can be stored with the patient information accompanied. Therefore, in the FPD, when transmitting the radiographic image data to the controller 3 , it is preferable to transmit it with the patient information accompanied.
[0174] Further, with respect to the number of radiographs, whenever the radiographic image data is stored with the patient information accompanied or simultaneously with transmission to the controller 3 , if the patient information is transmitted from the FPD to the reception computer 5 and the number of acquisition times of the same patient information is calculated by the reception computer 5 . the number of radiographing times corresponding to the patient information can be discriminated, so that the number of radiographing times information can be used for precalculation of the insurance point process.
[0175] Furthermore, needless to say, the present invention is not limited to this embodiment and can be modified appropriately.
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A diagnostic system which provides the imaging operator with the situation of the patients staying in a small-scale facility such as a medical practitioner or a clinic without increasing the man-hour such as input of examination order information and improves the diagnosis efficiency. When a visiting patient is received and registered by and in a reception computer ( 5 ), a patient information list showing the patients who visited the facility on the day is created. A patient list screen is displayed on a display section ( 221 ) of a reading apparatus ( 202 ). On the patient list screen, patient information on the patient to be imaged is specified, the patient information on the specified patient is sent to a controller ( 3 ). When image data created by an image generating apparatus ( 2 ) is sent to the controller ( 3 ), the controller ( 3 ) associates the image data with the patient information received from the reading apparatus ( 202 ) and stores them in a server ( 4 ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application No. 62/136,661, filed Mar. 23, 2015, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to tractor attachments and relates more particularly to a novel tractor attachment and to a tractor attachment kit.
[0003] Tractors are powerful motor vehicles commonly used in, for example, agriculture, landscaping, and construction to perform a variety of moving, lifting and other tasks. To perform such tasks, various types of specialized attachments are typically coupled to the tractor. One such specialized tractor attachment is a bucket, the bucket being coupled to the front end of the tractor using an assembly commonly referred to as a loader boom. One common type of loader boom comprises a pair of arms and a pair of mounts. The rear end of each arm is pivotally mounted on the tractor, and a mount is pivotally mounted on the front end of each arm. The bucket, in turn, is typically mechanically coupled to the pair of mounts. Pivotal movement of the arms relative to the tractor is typically provided by a first hydraulic mechanism, and pivotal movement of the mounts relative to the arms is typically provided by a second hydraulic mechanism. In this manner, the bucket may be raised or lowered by operation of the first hydraulic mechanism, and the bucket may be angularly adjusted by operation of the second hydraulic mechanism.
[0004] Referring now to FIGS. 1 and 2 , there are shown a front, perspective view and an enlarged, fragmentary, rear, perspective view of an exemplary conventional tractor assembly, the exemplary conventional tractor assembly being represented generally by reference numeral 11 .
[0005] Tractor assembly 11 , which is commercially available from Deere & Company (Moline, Ill.), comprises a tractor 13 . Although tractor 13 is depicted in FIG. 1 as a four-wheeled motor vehicle, it is to be understood that tractor 13 need not be a four-wheeled motor vehicle and may, instead, comprise other types of vehicles.
[0006] Tractor assembly 11 additionally comprises a bucket 15 .
[0007] Tractor assembly 11 further comprises a loader boom 17 . Loader boom 17 , which is also shown separately in FIG. 3( a ) , comprises a pair of arms 19 - 1 and 19 - 2 and a pair of mounts 21 - 1 and 21 - 2 . Arms 19 - 1 and 19 - 2 are pivotally mounted at their respective rear ends on tractor 13 . Pivotal movement of arms 19 - 1 and 19 - 2 relative to tractor 13 may be provided by a first hydraulic mechanism comprising one or more hydraulic cylinders 23 . Mounts 21 - 1 and 21 - 2 are pivotally mounted on the front ends of arms 19 - 1 and 19 - 2 , respectively. Pivotal movement of mounts 21 - 1 and 21 - 2 relative to arms 19 - 1 and 19 - 2 may be provided by a second hydraulic mechanism comprising one or more hydraulic cylinders 25 . Bucket 15 is mechanically coupled to mounts 21 - 1 and 21 - 2 . Such coupling is typically achieved by hooks on the rear of bucket 15 that matingly fit over the top ends 23 - 1 and 23 - 2 of mounts 21 - 1 and 21 - 2 , respectively, and by pins extending from the rear of bucket 15 that are received in pin holes 27 - 1 and 27 - 2 in mounts 21 - 1 and 21 - 2 , respectively (one such hook 29 and one such pin 31 being shown in FIG. 2 ).
[0008] The particulars of the loader boom, as well as the complementary structure on the bucket for attaching to the front end of the loader boom, tend to vary from one manufacturer to another. An example of an alternative conventional loader boom is shown in FIG. 3( b ) and is represented generally by reference numeral 35 . Loader boom 35 is similar in certain respects to loader boom 17 and comprises a pair of arms 37 - 1 and 37 - 2 that are adapted to be pivotally mounted at their respective rear ends on tractor 13 . Pivotal movement of arms 37 - 1 and 37 - 2 relative to tractor 13 may be effected by a mechanism similar to that used to move arms 19 - 1 and 19 - 2 of loader boom 17 . Loader boom 35 differs principally from loader boom 17 in that loader boom 35 does not include mounts 21 - 1 and 21 - 2 and, instead, includes a plurality of pins 39 - 1 through 39 - 4 . Pins 39 - 1 and 39 - 2 are adapted to couple arms 37 - 1 and 37 - 2 , respectively, to a bucket (not shown) by being inserted through plates 41 - 1 and 41 - 2 on arm 37 - 1 and through plates 41 - 3 and 41 - 4 on arm 37 - 2 , respectively, as well as through corresponding plates (not shown) that are fixedly mounted on the bucket. Pins 39 - 3 and 39 - 4 are adapted to couple the movable ends 45 - 1 and 45 - 2 of hydraulic cylinders 43 - 1 and 43 - 2 , respectively, to the bucket by being inserted through ends 45 - 1 and 45 - 2 , as well as through the aforementioned plates that are fixedly mounted on the bucket. Fasteners 47 - 1 through 47 - 4 may be used to retain pins 39 - 1 through 39 - 4 , respectively, in place.
[0009] As can be appreciated, there are situations in which it would be desirable to replace the functionality afforded by a bucket with the functionality afforded by another type of tractor attachment. As can also be appreciated, it would also be desirable to enable such a replacement to be made without requiring that changes be made to the loader boom. In other words, it would be desirable for the replacement attachment to be attachable to a conventional loader boom. Although some such replacement attachments exist, some of these replacement attachments suffer from certain shortcomings in terms of cost, weight, size, and/or variability in use.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide a novel tractor attachment.
[0011] According to a preferred feature of the invention, the tractor attachment as described above is a grapple assembly.
[0012] According to a preferred feature of the invention, the grapple assembly as described above is capable of being used with, but is not limited to being used with, a conventional loader boom mounted on a tractor.
[0013] According to another preferred feature of the invention, the grapple assembly as described above is a capable of being used in a plurality of different speed/force modes, such as a slower closing mode with a higher clamping force or a faster closing mode with a lower clamping force, and/or is capable of being used in a plurality of different size modes, such as a compact mode with individual grapple components disposed adjacent to or in contact with one another or an expanded mode with individual grapple components spaced apart from one another.
[0014] According to yet another preferred feature of the invention, the grapple assembly as described above overcomes at least some of the shortcomings of existing grapple attachments, such existing grapple attachments tending to be expensive, heavy, bulky, and lacking variability in use.
[0015] It is another object of the present invention to provide a novel tractor attachment kit.
[0016] According to a preferred feature of the invention, the kit as described above is a grapple assembly kit.
[0017] According to another preferred feature of the invention, the grapple assembly kit is capable of being assembled in a plurality of different ways, such as with different combinations of clamping and support components and/or with the same combination of clamping and/or support components arranged in different ways and/or with certain grapple components being operated in different speed/force modes.
[0018] According to one aspect of the invention, there is provided a tractor attachment mountable on a tractor loader boom, the tractor attachment comprising (a) a mounting assembly, the mounting assembly being removably mountable on the tractor loader boom; and (b) a clamping unit, the clamping unit being removably mounted on the mounting assembly, the clamping unit comprising an upper jaw and a lower jaw, the upper jaw being pivotally mounted on the lower jaw, the clamping unit further comprising means for moving the upper jaw relative to the lower jaw.
[0019] In another, more detailed feature of the invention, the upper jaw may be pivotally mounted on the lower jaw at one of a plurality of alternative pivot points.
[0020] In another, more detailed feature of the invention, the plurality of alternative pivot points may comprise a first pivot point and a second pivot point, the first pivot point producing a faster closing speed, the second pivot point producing a greater clamping force.
[0021] In another, more detailed feature of the invention, the clamping unit may further comprise at last one fang, the at least one fang being removably mounted on the upper jaw.
[0022] In another, more detailed feature of the invention, the mounting assembly may comprise a frame, the frame may comprise first and second rails and first and second brackets, the first and second brackets may interconnect the first and second rails and may have structure complementary to the tractor loader boom, and the clamping unit may be removably mounted on the first and second rails.
[0023] In another, more detailed feature of the invention, the tractor attachment may further comprise a lock for removably securing the clamping unit on the mounting assembly.
[0024] In another, more detailed feature of the invention, the mounting assembly may comprise a rail, the rail may have a notch, the clamping unit may comprise an opening, the opening may be aligned with the notch, and the lock may comprise a first member and a second member, the first member and the second member being generally perpendicular to one another, the first member extending through the notch and through the opening, the second member extending downwardly between the rail and the clamping unit.
[0025] According to another aspect of the invention, there is provided a tractor attachment kit for use in assembling a tractor attachment mountable on a tractor loader boom, the tractor attachment kit comprising (a) a mounting assembly, the mounting assembly being removably mountable on the tractor loader boom; and (b) a first clamping unit, the first clamping unit being removably mountable on the mounting assembly, the first clamping unit comprising an upper jaw and a lower jaw, the upper jaw being pivotally mounted on the lower jaw, the first clamping unit further comprising means for moving the upper jaw relative to the lower jaw.
[0026] In another, more detailed feature of the invention, the tractor attachment kit may further comprise a second clamping unit, the second clamping unit may be removably mountable on the mounting assembly, the second clamping unit may comprise an upper jaw and a lower jaw, the upper jaw may be pivotally mounted on the lower jaw, and the second clamping unit may further comprise means for moving the upper jaw relative to the lower jaw.
[0027] In another, more detailed feature of the invention, the mounting assembly may be sized to permit the first clamping unit and the second clamping unit to be concurrently mounted thereon.
[0028] In another, more detailed feature of the invention, the tractor attachment kit may further comprise a first support unit, and the first support unit may be removably mountable on the mounting assembly.
[0029] In another, more detailed feature of the invention, the mounting assembly may be sized to permit the first clamping unit and the support unit to be concurrently mounted thereon.
[0030] In another, more detailed feature of the invention, the tractor attachment kit may further comprise a second clamping unit and a third clamping unit, the second and third clamping units may be identical to the first clamping unit, the tractor attachment kit may further comprise a first support unit and a second support unit, the first and second support units may be identical to one another, each of the first and second support units may be removably mountable on the mounting assembly, and the mounting assembly may be sized to permit up to a threesome of clamping units and/or support units to be concurrently mounted thereon.
[0031] In another, more detailed feature of the invention, the tractor attachment kit may further comprise a pair of forklift tines removably mountable on the mounting assembly.
[0032] According to yet another aspect of the invention, there is provided a tractor attachment mountable on a tractor loader boom, the tractor attachment comprising (a) a mounting assembly, the mounting assembly being removably mountable on the tractor loader boom; (b) a first clamping unit, the first clamping unit being removably mounted on the mounting assembly, the first clamping unit comprising an upper jaw and a lower jaw, the upper jaw being pivotally mounted on the lower jaw, the first clamping unit further comprising means for moving the upper jaw relative to the lower jaw; and (c) one of a second clamping unit and a first support unit removably mounted on the mounting assembly, the second clamping unit comprising an upper jaw and a lower jaw, the upper jaw being pivotally mounted on the lower jaw, the second clamping unit further comprising means for moving the upper jaw relative to the lower jaw.
[0033] In another, more detailed feature of the invention, the second clamping unit may be removably mounted on the mounting assembly.
[0034] In another, more detailed feature of the invention, a third clamping unit may be removably mounted on the mounting assembly, the third clamping unit may comprise an upper jaw and a lower jaw, the upper jaw may be pivotally mounted on the lower jaw, and the third clamping unit may further comprise means for moving the upper jaw relative to the lower jaw.
[0035] In another, more detailed feature of the invention, the first support unit may be removably mounted on the mounting assembly.
[0036] In another, more detailed feature of the invention, a second support may be removably mounted on the mounting assembly.
[0037] In another, more detailed feature of the invention, the tractor attachment may further comprise the second clamping unit removably mounted on the mounting assembly.
[0038] The present invention is also directed to a method of assembling and disassembling a tractor attachment and to a method of using the tractor attachment kit described herein to reversibly assemble a tractor attachment.
[0039] Additional objects, as well as aspects, features and advantages, of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. In the description, reference is made to the accompanying drawings which form a part thereof and in which is shown by way of illustration various embodiments for practicing the invention. The embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The accompanying drawings, which are hereby incorporated into and constitute a part of this specification, illustrate various embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings wherein like reference numerals represent like parts:
[0041] FIG. 1 is a front, perspective view of a conventional tractor assembly;
[0042] FIG. 2 is an enlarged, fragmentary, rear, perspective view of the conventional tractor assembly of FIG. 1 ;
[0043] FIG. 3( a ) is an enlarged, front, perspective view of the loader boom shown in FIG. 1 , with certain components not being shown for the sake of clarity;
[0044] FIG. 3( b ) is an alternative conventional loader boom to the conventional loader boom shown in FIGS. 1, 2, and 3 ( a );
[0045] FIG. 4 is a perspective view of a first embodiment of a grapple assembly kit constructed according to the present invention;
[0046] FIGS. 5( a ) through 5( g ) are front perspective, rear perspective, front, rear, top, right side, and exploded perspective views, respectively, of the mounting assembly shown in FIG. 4 ;
[0047] FIGS. 6( a ) and through 6 ( c ) are front perspective, right side, and partly exploded perspective views, respectively, of one of the clamping units shown in FIG. 4 , the clamping unit being shown in FIGS. 6( a ) and 6( b ) in a closed state and with the upper and lower jaws of the clamping unit being coupled together in a first manner that results in a comparatively faster closing of the jaws with a comparatively lower clamping force;
[0048] FIGS. 7( a ) and 7( b ) are side and rear perspective views, respectively, of the clamping unit shown in FIGS. 6( a ) through 6( c ) , the clamping unit being shown in completely open and partially open states, respectively;
[0049] FIGS. 8( a ) and 8( b ) are front perspective and exploded perspective views, respectively, of the lower jaw of the clamping unit shown in FIGS. 6( a ) through 6( c ) ;
[0050] FIGS. 9( a ) and 9( b ) are front perspective and exploded perspective views, respectively, of the upper jaw of the clamping unit shown in FIGS. 6( a ) through 6( c ) ;
[0051] FIGS. 10( a ) and 10( b ) are right side views, showing the clamping unit of FIGS. 6( a ) through 6( c ) after it has been configured so that the upper and lower jaws of the clamping unit are coupled together at an alternative pivot point to cause a comparatively slower closing of the jaws with a comparatively higher clamping force than that of FIGS. 6( a ) through 6( c ) , the clamping unit shown in an open state in FIG. 10( a ) and in a closed state in FIG. 10( b ) ;
[0052] FIGS. 10( c ) and 10( d ) are fragmentary right perspective and fragmentary left perspective views, respectively, of an alternative clamping unit to the clamping unit shown in FIGS. 6( a ) through 6( c ) ;
[0053] FIGS. 11( a ) and 11( b ) are front perspective and exploded perspective views, respectively, of one of the support units shown in FIG. 4 ;
[0054] FIGS. 12( a ) through 12( d ) are perspective, side, top, and exploded perspective views, respectively, of one of the locking members shown in FIG. 4 ;
[0055] FIGS. 13( a ) through 13( d ) are rear perspective, enlarged fragmentary rear perspective, enlarged fragmentary top, and enlarged fragmentary rear views, respectively, of one example of a tractor attachment that may be assembled using the kit of FIG. 4 ;
[0056] FIG. 13( e ) is a section view taken along line 1 - 1 of FIG. 13( d ) ;
[0057] FIG. 13( f ) is a section view taken along line 2 - 2 of FIG. 13( d ) ;
[0058] FIGS. 14( a ) through 14( e ) are front perspective, rear perspective, right side, partly exploded right side, and front views, respectively, of the tractor attachment of FIGS. 13( a ) through 13( f ) , with the locking members of the tractor attachment not being shown for the sake of simplicity;
[0059] FIGS. 15( a ) through 15( d ) are front perspective, rear perspective, front, and top views, respectively, of a second example of a tractor attachment that may be assembled using the kit of FIG. 4 , with the locking members of the tractor attachment not being shown for the sake of simplicity;
[0060] FIGS. 16( a ) through 16( d ) are front perspective, rear perspective, front, and top views, respectively, of a third example of a tractor attachment that may be assembled using the kit of FIG. 4 , with the locking members of the tractor attachment not being shown for the sake of simplicity;
[0061] FIGS. 17( a ) through 17( d ) are front perspective, rear perspective, front, and top views, respectively, of a fourth example of a tractor attachment that may be assembled using the kit of FIG. 4 , with the locking members of the tractor attachment not being shown for the sake of simplicity;
[0062] FIGS. 18( a ) through 18( d ) are front, front perspective, rear perspective, and right side views, respectively, of the tractor attachment of FIGS. 13( a ) through 13( f ) being used to hold a log so that the log may be cut into smaller pieces using a chainsaw or the like, the locking members of the tractor attachment not being shown for the sake of simplicity;
[0063] FIGS. 19( a ) through 19( c ) are front, front perspective, and rear perspective views, respectively, of the tractor attachment of FIGS. 13( a ) through 13( f ) , the tractor attachment being shown with its support units positioned flush against its clamping unit, the locking members of the tractor attachment not being shown for the sake of simplicity;
[0064] FIGS. 20( a ) through 20( c ) are front perspective, rear perspective, and right side views, respectively, of a forklift attachment that may be constructed according to the teachings of the present invention;
[0065] FIGS. 21( a ) through 21( d ) are front perspective, rear perspective, partly exploded front perspective, and right side views, respectively, of a snow plow adapter attachment that may be constructed according to the present invention;
[0066] FIGS. 22( a ) through 22( d ) are front perspective, rear perspective, partly exploded front perspective, and right side views, respectively, of a ball mount adapter attachment that may be constructed according to the present invention;
[0067] FIGS. 23( a ) through 23( f ) are front perspective, rear perspective, front, top, right side, and exploded perspective views, respectively, of a first alternative mounting assembly to the mounting assembly shown in FIGS. 4, 5 ( a ), 5 ( b ), 5 ( c ), 5 ( d ), 5 ( e ), 5 ( f ) and 5 ( g ); and
[0068] FIGS. 24( a ) through 24( c ) are front perspective, rear perspective, and exploded perspective views, respectively, of a second alternative mounting assembly to the mounting assembly shown in FIGS. 4, 5 ( a ), 5 ( b ), 5 ( c ), 5 ( d ), 5 ( e ), 5 ( f ) and 5 ( g ).
DETAILED DESCRIPTION OF THE INVENTION
[0069] Referring now to FIG. 4 , there is shown a perspective view of a first embodiment of a grapple assembly kit constructed according to the present invention, the grapple assembly kit being represented generally by reference numeral 51 .
[0070] Grapple assembly kit 51 , which may be used with a loader boom, such as, for example, loader boom 17 , may comprise a mounting assembly 53 , a plurality of clamping units 55 - 1 through 55 - 3 , a plurality of support units 57 - 1 through 57 - 2 , and a plurality of locking members 59 - 1 through 59 - 6 . As will be discussed below in greater detail, clamping units 55 - 1 through 55 - 3 , support units 57 - 1 and 57 - 2 , and locking member 59 - 1 through 59 - 6 are preferably modular in construction. As a result, a great number of different combinations of clamping units 55 and/or support units 57 and/or locking members 59 may be mounted on mounting assembly 53 , all such combinations coming within the scope of the present invention. In addition, it is to be understood that, although grapple assembly kit 51 is shown in the present embodiment as having three clamping units 55 - 1 through 55 - 3 , two support units 55 - 1 and 55 - 2 , and six locking members 59 - 1 through 59 - 6 , grapple assembly kit 51 may be modified so that the number of clamping units 55 - 1 through 55 - 3 may be greater than or less than three and/or so that the number of support units 55 - 1 and 55 - 2 may be greater than or less than two and/or so that the number of locking members 59 - 1 through 59 - 6 may be greater than or less than six. Additionally, although grapple assembly kit 51 is shown in the present application as being capable of mounting as few as a single clamping unit 55 (or a single support unit 57 ) on mounting assembly 53 or as many as up to three clamping units 55 and/or support units 57 on mounting assembly 53 , it is to be understood that the dimensions of mounting assembly 53 , clamping units 55 , and/or support units 57 may be modified to accommodate more than a total of three clamping units 55 and/or support units 57 .
[0071] Mounting assembly 53 , which is also shown separately in FIGS. 5( a ) through 5( g ) , may comprise a pair of mounting rails 61 - 1 and 61 - 2 and a pair of mounting brackets 63 - 1 and 63 - 2 . Mounting rails 61 - 1 and 61 - 2 and mounting brackets 63 - 1 and 63 - 2 may collectively form a generally rectangular frame. Rails 61 - 1 and 61 - 2 , which are preferably made of a high strength steel or other similarly suitable material, may be arranged generally parallel to one another. Rail 61 - 1 may be shaped to include a rear portion 65 and a front portion 67 . Rear portion 65 and front portion 67 of rail 61 - 1 may be separately fabricated and then fixedly joined to one another by suitable means, such as by welding; alternatively, rear portion 65 and front portion 67 of rail 61 - 1 may be fabricated as a unitary structure. As will be discussed further below, rear portion 65 of rail 61 - 1 may be fixed by welding or other suitable means to each of mounting brackets 63 - 1 and 63 - 2 . Front portion 65 of rail 61 - 1 may be shaped to include a plurality of notches 69 spaced along a top surface 71 thereof.
[0072] Rail 61 - 2 may be shaped to include a rear portion 73 and a front portion 75 . Rear portion 73 and front portion 75 of rail 61 - 2 may be separately fabricated and then fixedly joined to one another by suitable means, such as by welding; alternatively, rear portion 73 and front portion 75 of rail 61 - 2 may be fabricated as a unitary structure. As will be discussed further below, rear portion 73 of rail 61 - 2 may be fixed by welding or other suitable means to each of mounting brackets 63 - 1 and 63 - 2 . Front portion 75 of rail 61 - 2 may be shaped to include a notch 77 disposed along a bottom surface 79 thereof.
[0073] Brackets 63 - 1 and 63 - 2 , which are preferably made of a high strength steel or other similarly suitable material, may be arranged generally parallel to one another and generally perpendicularly relative to each of rails 61 - 1 and 61 - 2 . Bracket 63 - 1 may be shaped to include a rear portion 81 and a pair of side portions 83 - 1 and 83 - 2 . In a similar fashion, bracket 63 - 2 may be shaped to include a rear portion 85 and a pair of side portions 87 - 1 and 87 - 2 . Each of brackets 63 - 1 and 63 - 2 may be fabricated by separately forming the respective rear and side portions thereof and then by joining the rear and side portions together by suitable means, such as by welding. Alternatively, the respective rear and side portions of each of brackets 63 - 1 and 63 - 2 may be fabricated as a unitary structure. A first hook 91 may be fixed to the rear surface of rear portion 81 of bracket 63 - 1 , and a second hook 93 may be fixed to the rear surface of rear portion 85 of bracket 63 - 2 . Hooks 91 and 93 may be appropriately shaped to matingly fit over the top ends of the mounts of a suitably constructed loader boom (such as, for example, mounts 21 - 1 and 21 - 2 , respectively, of loader boom 17 , mounts 21 - 1 and 21 - 2 being seen best in FIG. 3( a ) ) for use in mechanically coupling brackets 63 - 1 and 63 - 2 to the mounts of the loader boom. It is to be understood that, although hooks 91 and 93 are shown in the present embodiment as being separately constructed from rear portions 81 and 85 , respectively, hooks 91 and 93 may be integrally formed with rear portions 81 and 85 , respectively. A first pin 97 may be provided on rear portion 81 of bracket 63 - 1 and may project rearwardly therefrom, and a second pin 99 may be provided on rear portion 85 of bracket 63 - 2 and may project rearwardly therefrom. Pins 97 and 99 may be appropriately dimensioned for insertion through the pin holes in the mounts of a suitably constructed loader boom (such as, for example, pin holes 27 - 1 and 27 - 2 , respectively, of loader boom 17 , pin holes 27 - 1 and 27 - 2 being seen best in FIG. 3( a ) ) for use in mechanically coupling brackets 63 - 1 and 63 - 2 to the mounts of the loader boom. Pin 97 may be shaped to include a transverse through hole 101 , and pin 99 may be similarly shaped to include a transverse through hole 103 . Each of through holes 101 and 103 may be used to receive a cotter pin (not shown) or the like for retaining pins 97 and 99 in the mounts of the loader boom. Pins 97 and 99 may be integrally formed with rear portions 81 and 85 , respectively, or, as shown in the present embodiment, pins 97 and 99 may be fabricated separately from rear portions 81 and 85 , respectively, and then may be joined thereto by suitable means, such as by welding.
[0074] Each of side portions 83 - 1 and 83 - 2 of bracket 63 - 1 and each of side portions 87 - 1 and 87 - 2 of bracket 63 - 2 may be fixedly mounted on each of mounting rails 61 - 1 and 61 - 2 . In this manner, when mounting assembly 53 is mounted on the loader boom of a tractor, rails 61 - 1 and 61 - 2 may be disposed generally horizontally relative to the ground, and brackets 83 - 1 and 83 - 2 may be disposed generally perpendicularly relative to the ground.
[0075] One or more voids 110 of various shapes and sizes may be provided in brackets 63 - 1 and 63 - 2 to reduce the weight thereof.
[0076] As will become apparent from the description to follow, mounting assembly 53 is preferably provided in a fully assembled state, as is shown in FIGS. 4 and 5 ( a ) through 5 ( f ), and is not intended to be disassembled thereafter into its component parts. Mounting assembly 53 may, however, be removably mounted on the loader boom of a tractor. The mounting of mounting assembly 53 on the loader boom of a tractor may be accomplished by matingly positioning hooks 91 and 93 over and around the respective top ends of the mounts of the loader boom (such as, for example, mounts 21 - 1 and 21 - 2 of loader boom 17 , mounts 21 - 1 and 21 - 2 being seen best in FIG. 3( a ) ) and then by inserting pins 97 and 99 through the pin holes of the loader boom (such as, for example, pin holes 27 - 1 and 27 - 2 of loader boom 17 , pin holes 27 - 1 and 27 - 2 being seen best in FIG. 3( a ) ). Cotter pins or the like then may be used to retain pins 97 and 99 in place in the mounts. To remove mounting assembly 53 from the loader boom, one may reverse the sequence of steps described above.
[0077] Referring back now to FIG. 4 , clamping units 55 - 1 through 55 - 3 may be identical in size, shape and construction to one another. Therefore, it is to be understood that the discussion below of the construction of clamping unit 55 - 1 may be equally applicable to clamping units 55 - 2 and 55 - 3 .
[0078] Clamping unit 55 - 1 , which is also shown separately in FIGS. 6( a ), 6( b ), 6( c ), 7( a ) and 7( b ) , may comprise a lower jaw 121 , an upper jaw 123 , a pair of pivot assemblies 125 - 1 and 125 - 2 , and a hydraulic cylinder assembly 127 . (It should be understood that hydraulic cylinder assembly 127 could be replaced with other mechanisms for moving upper jaw 123 relative to lower jaw 121 , such mechanisms including, but not being limited to, conventional mechanical, electrical, and electromechanical mechanisms, etc.)
[0079] Lower jaw 121 , which is also shown separately in FIGS. 8( a ) and 8( b ) , may comprise a pair of side members 131 - 1 and 131 - 2 . Side members 131 - 1 and 131 - 2 , which may be substantially identical to one another, may be generally L-shaped structures, each of which may include a generally horizontal portion 133 and a generally vertical portion 135 . Generally horizontal portion 133 may be shaped to include a plurality of jagged gripping elements 137 at its free end. Generally vertical portion 135 may be shaped to include along its rear an upper hook 139 and a lower hook 141 . Upper hook 139 may be sized and shaped to permit its mounting around the top of front portion 67 of rail 61 - 1 . Lower hook 141 may be sized and shaped to permit its mounting around the bottom of front portion 75 of rail 61 - 2 . Generally vertical portion 135 may also be shaped to include an upper hole 145 and a lower hole 147 . As will be discussed further below, holes 145 and 147 may be alternatively used to receive pivot assemblies 125 . Generally vertical portion 135 may additionally be shaped to include a T-shaped opening 149 , the purpose of which will become apparent below.
[0080] Lower jaw 121 may additionally comprise a plurality of members that may be used to join together side members 131 - 1 and 131 - 2 . Such joining members may include a pair of tubes 151 and 153 , a plate 155 , and a plate 157 . Tube 151 may have a first end 151 - 1 inserted into an opening 161 of side member 131 - 1 and fixed therewithin, for example, by welding, and a second end 151 - 2 inserted into an opening 163 of side member 131 - 2 and fixed therewithin, for example, by welding. In a similar fashion, tube 153 may have a first end 153 - 1 inserted into an opening 165 of side member 131 - 1 and fixed therewithin, for example, by welding, and a second end 153 - 2 inserted into an opening 167 of side member 131 - 2 and fixed therewithin, for example, by welding. Plate 155 may have a first end 155 - 1 inserted into the vertical portion of T-shaped opening 149 of side member 131 - 1 and fixed therewithin, for example, by welding, and a second end 155 - 2 inserted into the vertical portion of T-shaped opening 149 of side member 131 - 2 and fixed therewithin, for example, by welding. In addition, plate 155 may be shaped to include a plurality of transverse openings 171 , one or more of which may be used to receive an end of a locking member 59 for use in securing clamping unit 55 - 1 to mounting assembly 53 . Plate 157 may have a first end 157 - 1 inserted into the horizontal portion of T-shaped opening 149 of side member 131 - 1 and fixed therewithin, for example, by welding, and a second end 157 - 2 inserted into the horizontal portion of T-shaped opening 149 of side member 131 - 2 and fixed therewithin, for example, by welding. In addition, plate 157 may be shaped to include a pair of slots 173 and 175 . Slot 173 may be used to receive a mounting member 177 , which may be fixed to plate 157 , for example, by welding, and slot 175 may be used to receive a mounting member 179 , which may be fixed to plate 157 , for example, by welding. Mounting members 177 and 179 may be used in mounting the fixed end of a hydraulic cylinder.
[0081] Lower jaw 121 may further comprise a plurality of support members that may be used to support and/or strengthen lower jaw 121 . Such support members may include a plate 181 and a plurality of gussets 183 - 1 through 183 - 8 . Plate 181 may be inserted around tubes 151 and 153 and fixed thereto, for example, by welding. Gusset 183 - 1 may be inserted into an opening 185 in side member 131 - 1 and may be fixed to side member 131 - 1 and to tube 151 by welding or other suitable means. Gussets 183 - 2 and 183 - 3 may be inserted into openings 187 and 189 , respectively, in side member 131 - 1 and may be fixed to side member 131 - 1 and to tube 153 by welding or other suitable means. Gusset 183 - 4 may be inserted into an opening 191 in side member 131 - 2 and may be fixed to side member 131 - 2 and to tube 151 by welding or other suitable means. Gussets 183 - 5 and 183 - 6 may be inserted into openings 193 and 195 , respectively, in side member 131 - 2 and may be fixed to side member 131 - 2 and to tube 153 by welding or other suitable means. Gusset 183 - 7 may be fixed to plates 155 , 157 , and 177 by welding or other suitable means, and gusset 183 - 8 may be fixed to plates 155 , 157 , and 179 by welding or other suitable means.
[0082] The components making up lower jaw 121 may be made of a high strength steel or other similarly suitable material. Voids 189 of various shapes and sizes may be provided in one or more of the components of lower jaw 121 to lessen the overall weight of lower jaw 121 .
[0083] Upper jaw 123 , which is also shown separately in FIGS. 9( a ) and 9( b ) , may comprise a pair of side members 201 - 1 and 201 - 2 . Side members 201 - 1 and 201 - 2 , which may be substantially identical to one another, may be generally L-shaped structures, each of which may include a first portion 203 and a second portion 205 . First portion 203 may be shaped to include a plurality of jagged gripping elements 207 on its bottom surface. In addition, first portion 203 may be shaped to include a hole 209 , which may be used to receive pivot assemblies 125 . First portion 205 may be shaped to include a plurality of jagged gripping elements 211 on its rear surface.
[0084] Upper jaw 123 may additionally comprise a plurality of members that may be used to join together side members 201 - 1 and 201 - 2 . Such joining members may include a plate 215 and a plate 217 . Plate 215 may have a first end 219 - 1 inserted into an opening 221 of side member 201 - 1 and fixed therewithin, for example, by welding, and a second end 219 - 2 inserted into an opening 223 of side member 201 - 2 and fixed therewithin, for example, by welding. The bottom surface of plate 215 may be shaped to include a plurality of jagged gripping elements 227 . Plate 217 may be shaped to include a plurality of tabs 231 - 1 through 231 - 3 provided along one side thereof and a plurality of tabs 233 - 1 through 233 - 3 provided along an opposite side thereof. Tabs 231 - 1 through 231 - 3 may be inserted into openings 235 - 1 through 235 - 3 , respectively, of first portion 203 of side member 201 - 1 and may be fixed thereto by welding or other suitable means, and tabs 233 - 1 through 233 - 3 may be inserted into openings 237 - 1 through 237 - 3 , respectively, of first portion 203 of side member 201 - 2 and may be fixed thereto by welding or other suitable means.
[0085] Upper jaw 123 may further comprise a pair of mounting members 241 - 1 and 241 - 2 , which may be used in the mounting of the movable end of a hydraulic cylinder. Mounting member 241 - 1 may be shaped to include a first tab 243 and a second tab 245 . First tab 243 and second tab 245 may be inserted into openings 247 and 249 , respectively, of plate 217 and may be fixed thereto by welding or other suitable means. Mounting member 241 - 2 may be shaped to include a first tab 251 and a second tab (not shown). First tab 251 and the second tab of mounting member 241 - 2 may be inserted into openings 255 and 257 , respectively, of plate 217 and may be fixed thereto by welding or other suitable means.
[0086] The components making up upper jaw 123 may be made of a high strength steel or other similarly suitable material. Voids 259 of various shapes and sizes may be provided in one or more of the components of upper jaw 123 to lessen the overall weight of upper jaw 123 . For reasons to become apparent below, upper jaw 123 may be dimensioned relative to lower jaw 121 so that holes 209 of upper jaw 123 may be positioned just interior to holes 145 or 147 of lower jaw 121 .
[0087] Pivot assemblies 125 - 1 and 125 - 2 (seen best in FIG. 6( c ) ), which may be used to pivotally mount upper jaw 123 on lower jaw 121 , may be identical to one another, and each may include a threaded bolt 261 , a first washer 263 , a sleeve 265 , a second washer 267 , and a nut 269 . Bolt 261 may be appropriately dimensioned to pass through either hole 145 or hole 147 of lower jaw 121 and through hole 209 of upper jaw 123 , with the head 271 of bolt 261 being positioned on the interior side of upper jaw 123 . First washer 263 may also be positioned on the interior side of upper jaw 123 . Sleeve 265 may be positioned within hole 209 of upper jaw 123 , second washer 267 may be positioned between upper jaw 123 and lower jaw 121 , and nut 269 may be positioned on the exterior side of lower jaw 121 .
[0088] By inserting bolts 261 of pivot assemblies 125 - 1 and 125 - 2 through either upper hole 145 of lower jaw 121 (see, for example, FIGS. 6( b ) and 7( a ) ) or through lower hole 147 of lower jaw 121 (see, for example, FIGS. 10( a ) and 10( b ) ), one can adjust the speed with which upper jaw 123 closes on lower jaw 121 and the clamping force between jaws 121 and 123 . More specifically, when bolt 261 is inserted through upper hole 145 , the closing speed of upper jaw 123 is faster than the closing speed of upper jaw 123 when bolt 261 is inserted through lower hole 147 . On the other hand, when bolt 261 is inserted through lower hole 147 , the clamping force between jaws 121 and 123 is greater than the clamping force that is produced when bolt 261 is inserted through upper hole 145 . For example, when the spacing between the respective centers of upper hole 145 and hole 209 is approximately 2.69 inches, when the spacing between the respective centers of lower hole 147 and hole 209 is approximately 4.30 inches, and when using a hydraulic cylinder with a 4240 lb cylinder force at 2400 psi, the increase in clamping force using lower hole 147 , instead of upper hole 145 , may be greater by, for example, approximately 114% when upper jaw 123 is at its most open position, may be greater by, for example, approximately 45% when upper jaw 123 is at its midpoint, and may be greater by, for example, approximately 72% when upper jaw 123 is in its closed position.
[0089] As seen best in FIG. 6( c ) , hydraulic cylinder assembly 127 may comprise a hydraulic cylinder 281 and hardware for mounting hydraulic cylinder 281 to jaws 121 and 123 . Hydraulic cylinder 281 , the operation of which may be controlled by conventional means (not shown), may comprise a fixed portion 283 and a movable portion 285 . Fixed portion 283 may include a tubular member 287 . Tubular member 287 may be appropriately dimensioned to be coupled to mounting members 177 and 179 of lower jaw 121 using hardware that may include a threaded bolt 291 , a plurality of washers 293 , and a nut 295 . Movable portion 285 of hydraulic cylinder 281 may include a tubular member 297 . Tubular member 297 may be appropriately dimensioned to be coupled to mounting members 241 - 1 and 241 - 2 of upper jaw 123 using hardware that may include a threaded bolt 299 , a plurality of washers 301 , and a nut 303 .
[0090] Referring now to FIGS. 10( c ) and 10( d ) , there are shown fragmentary right perspective and fragmentary left perspective views, respectively, of an alternative type of clamping unit to the type of clamping unit shown in FIGS. 6( a ) through 6( c ) , the alternative type of clamping unit being represented generally by reference numeral 56 . (Clamping unit 56 is shown in the present embodiment equipped with hydraulic hoses 58 - 1 and 58 - 2 used in the operation of hydraulic cylinder 281 .)
[0091] Clamping unit 56 may be similar in most respects to clamping units 55 - 1 through 55 - 3 , the principal difference between the two types of clamping units being that clamping unit 56 may further comprise a pair of fangs 60 - 1 and 60 - 2 , which may be provided to endow clamping unit 56 with an enhanced gripping power. Fang 60 - 1 may be securely mounted to side member 201 - 1 of upper jaw 123 , and fang 60 - 2 may be securely mounted to side member 201 - 2 of upper jaw 123 . Fangs 60 - 1 and 60 - 2 may be secured to upper jaw 123 using suitable hardware. For example, in the present embodiment, a washer (not shown) may be inserted over each of a pair of bolts 62 , and bolts 62 may then be inserted through openings in fang 60 - 1 and then through an opening in side member 201 - 1 . An additional washer (not shown) may then be inserted over each of bolts 62 from the inside of side member 201 - 1 , and a nut 64 may then be secured to each of bolts 62 . Fang 60 - 2 may be secured to side member 201 - 2 in a corresponding manner. If desired, fangs 60 - 1 and 60 - 2 may be removably mounted on upper jaw 123 to permit their attachment and removal when desired. In another embodiment (not shown), fangs 60 - 1 and 60 - 2 may be replaced with a single fang that is centrally disposed on upper jaw 123 .
[0092] As can be appreciated, any one or more of clamping units 55 - 1 through 55 - 3 may be replaced with a corresponding number of clamping units 56 . Alternatively, clamping units 55 - 1 through 55 - 3 may be reversibly converted to clamping unit 56 and vice versa by the attachment and removal of fangs 60 - 1 and 60 - 2 .
[0093] Referring back now to FIG. 4 , support units 57 - 1 and 57 - 2 may be identical in size, shape and construction to one another. Therefore, it is to be understood that the discussion below of the construction of support unit 57 - 1 may be equally applicable to support unit 57 - 2 .
[0094] Support unit 57 - 1 , which is also shown separately in FIGS. 11( a ) and 11( b ) , may be similar in size, shape and construction to lower jaw 121 of clamping unit 55 - 1 , some of the more significant differences between the two structures being that support unit 57 - 1 may not include the following structures of lower jaw 121 : plate 157 , mounting members 177 and 179 , and gussets 183 - 7 and 183 - 8 . In addition, whereas side members 131 - 1 and 131 - 2 of lower jaw 121 may include a T-shaped opening 149 , support unit 57 - 1 may include side members 321 - 1 and 321 - 2 that may include a rectangular opening 323 . Additionally, side members 321 - 1 and 321 - 2 of support unit 57 - 1 may differ from lower jaw 121 of clamping unit 55 - 1 in that, instead of having an upper hole 145 and a lower hole 147 , each of side members 321 - 1 and 321 - 2 may have an upper hole 325 and a lower hole 327 . Upper hole 325 and lower hole 327 may be centered in analogous locations to upper hole 145 and lower hole 147 , respectively, but may have an increased diameter, as compared to upper hole 145 and lower hole 147 , so that each of holes 325 and 327 is large enough to receive nut 269 of pivot assembly 125 of a neighboring clamping unit, thereby enabling the side members of neighboring support and clamping units to be brought into close proximity or contact with one another. Finally, support unit 57 - 1 may differ from lower jaw 121 of clamping unit 55 - 1 in that support unit 57 - 1 may include a plate 331 , instead of plate 155 . Plate 331 may be shaped to include a plurality of transverse openings 333 , one or more of which may be used to receive an end of a locking member 59 for use in securing support unit 57 - 1 to mounting assembly 53 .
[0095] Like lower jaw 121 of clamping unit 55 - 1 , support unit 57 - 1 may be made of a high strength steel or similarly suitable material.
[0096] Referring back now to FIG. 4 , locking members 59 - 1 through 59 - 6 may be identical in size, shape and construction to one another. Therefore, it is to be understood that the discussion below of the construction of locking member 59 - 1 may be equally applicable to each of locking members 59 - 2 through 59 - 6 .
[0097] Locking member 59 - 1 , which is also shown separately in FIGS. 12( a ) through 12( d ) , may comprise a first member 351 and a second member 353 . First member 351 , which may be made of a high strength steel or other similarly suitable material, may be generally rectangular in shape and may comprise a front portion 355 , an intermediate portion 357 , and a rear portion 359 . As will be discussed further below, first member 351 may be appropriately dimensioned so that intermediate portion 357 may be received within a notch 69 of mounting assembly 53 , with front portion 355 extending forwardly so that it may extend either through a transverse opening 171 in a clamping unit 55 or through a transverse opening 333 in a support unit 57 and with rear portion 359 extending rearwardly from notch 69 . Rear portion 359 may have a width w 1 that may be less than the width w 2 of intermediate portion 357 , and front portion 355 may have a width w 3 that may be intermediate to that of intermediate portion 357 and rear portion 359 . (Alternatively, in another embodiment (not shown), the width w 3 of front portion 355 may be the same as or greater than the width w 2 of intermediate portion 357 .) Rear portion 359 may have a length l 1 that may permit locking member 59 - 1 to be grasped and manipulated via rear portion 359 .
[0098] Second member 353 , which may also be made of a high strength steel or similarly suitable material, may be generally rectangular in profile and may comprise a first end 361 and a second end 363 . First end 361 of second member 353 may be received within an opening 365 in first member 351 , and, with first end 361 thus received within opening 365 , second member 353 may be fixed to first member 351 by welding or other suitable means. First member 351 and second member 353 may be oriented generally perpendicularly to one another, and second member 353 may be positioned along the length of first member 351 so that, when intermediate portion 357 of first member 351 is positioned within a notch 69 of mounting assembly 53 , second member 353 may be positioned between mounting assembly 53 and whichever of clamping unit 55 or support unit 57 is secured to mounting assembly 53 .
[0099] It is to be understood that, although locking member 59 - 1 is shown in the present embodiment as being made from two separate pieces that are joined to one another, namely, first member 351 and second member 353 , locking member 59 - 1 could be fabricated as a unitary structure.
[0100] A void 371 may be provided in locking member 59 - 1 for use in fastening to the attachment.
[0101] Referring now to FIGS. 13( a ) through 13( f ) , there are shown various views of one example of a tractor attachment constructed using grapple assembly kit 51 , the exemplary tractor attachment illustrating how a locking member 59 may be used in securing a clamping unit 55 or a support unit 57 to mounting assembly 53 .
[0102] The tractor attachment shown in FIGS. 13( a ) through 13( f ) is represented generally by reference numeral 401 and may comprise mounting assembly 53 , a single clamping unit (the clamping unit being represented in the present embodiment by clamping unit 55 - 1 ), and a pair of support units, one on each side of the clamping unit (the support units being represented in the present embodiment by support units 57 - 1 and 57 - 2 ). Clamping unit 55 - 1 may be mounted on mounting assembly 53 by positioning hooks 139 of clamping unit 55 - 1 around the top of front portion 67 of rail 61 - 1 of mounting assembly 53 and by positioning hooks 141 of clamping unit 55 - 1 around the bottom of front portion 75 of rail 61 - 2 of mounting assembly 53 . In like fashion, each of support units 57 - 1 and 57 - 2 may be mounted on mounting assembly 53 by positioning hooks 139 of support units 57 - 1 and 57 - 2 around the top of front portion 67 of rail 61 - 1 of mounting assembly 53 and by positioning hooks 141 of support units 57 - 1 and 57 - 2 around the bottom of front portion 75 of rail 61 - 2 of mounting assembly 53 . Then, to secure the thus-mounted clamping unit 55 - 1 or support units 57 - 1 and 57 - 2 to mounting assembly 53 , one or more locking members 59 may be used in the manner hereinafter described. More specifically, each mounting member 59 may be held by its rear portion 359 in the hand of a user and may be oriented so that its second member 353 is directed generally upwardly. Then, front portion 355 of mounting member 59 may be manually inserted first through a notch 69 in front portion 67 of rail 61 - 1 and then, depending on the type of unit being secured to mounting assembly 53 , either through a transverse opening 171 in a clamping unit 55 that is aligned with the notch 69 or through a transverse opening 333 in a support unit 57 that is aligned with the notch 69 . Such insertion of front portion 355 may proceed until further insertion is not possible. Rear portion 359 may then be manually rotated approximately 180 degrees until second member 353 extends downwardly between rail 61 - 1 and the clamping unit or support unit. With locking member 59 thus positioned, the clamping unit 55 or support unit 57 cannot be removed from mounting assembly. The above-described process is illustrated, at least in part, by FIGS. 13( a ) through 13( f ) , in which locking member 59 - 1 is shown in its fully installed state to secure support unit 57 - 1 to rail 61 - 1 , locking member 59 - 2 is shown in the process of being rotated after having been inserted through notch 69 and opening 333 , and locking member 59 - 3 is shown in its fully installed state to secure clamping unit 55 - 1 to rail 61 - 1 .
[0103] As can be appreciated, to remove a thus-locked clamping unit 55 or support unit 57 , one may simply rotate locking member 59 approximately 180 degrees and then withdraw locking member 59 from the clamping unit 55 or support unit 57 and then from notch 69 . With locking member 59 thus removed, a clamping unit 55 or a support unit 57 that had previously been mounted on mounting assembly 53 may thereafter be removed therefrom, thereby facilitating the transport and/or storage of the components of kit 51 .
[0104] It is to be understood that the number of locking members 59 used per clamping unit 55 or support unit 57 may vary. For example, in the present embodiment, two locking members 59 - 1 and 59 - 2 are shown being used with support unit 57 - 1 , and one locking member 59 - 3 is shown being used with clamping unit 55 - 1 . (Also, although no locking members 59 are shown being used with support unit 57 - 2 , the use of at least one such locking member 59 is preferred.) In general, it is preferred that at least two locking members 59 be used per clamping unit 55 or support unit 57 . In addition, it is to be understood that the selection of which notch 69 or which opening 171 or 333 may be used for use with a locking member 59 may vary.
[0105] Because of the modular nature of clamping units 55 and support unit 57 , various combinations of clamping units 55 and support units 57 may be mounted on mounting assembly 53 to create a variety of different grapple-type tractor attachments. For example, FIGS. 14( a ) through 14( e ) are various additional views of tractor attachment 401 , with locking members 59 not being shown for the sake of simplicity. By contrast, FIGS. 15( a ) through 15( d ) are various views of a second example of a grapple-type tractor attachment that may be constructed using kit 51 , the grapple-type tractor attachment of FIGS. 15( a ) through 15( d ) being represented generally by reference numeral 501 . Tractor attachment 501 may differ principally from tractor attachment 401 in that tractor attachment 501 may not include support units 57 - 1 and 57 - 2 . (Due to the presence of support units 57 - 1 and 57 - 2 in tractor attachment 401 , tractor attachment 401 may possess increased support for more load capacity than may be the case with tractor attachment 501 .) FIGS. 16( a ) through 16( d ) are various views of a third example of a grapple-type tractor attachment that may be constructed using kit 51 , the grapple-type tractor attachment of FIGS. 16( a ) through 16( d ) being represented generally by reference numeral 601 . Tractor attachment 601 may differ from tractor attachment 401 in that grapple unit 55 - 1 of tractor attachment 401 may be replaced with support unit 57 - 1 in tractor attachment 601 and in that support units 57 - 1 and 57 - 2 of tractor attachment 401 may be replaced with grapple units 55 - 1 and 55 - 2 , respectively, in tractor attachment 601 . As compared to tractor attachments 401 and 501 , tractor attachment 601 may provide greater clamping power, and, as compared to tractor attachment 501 , tractor attachment 601 may provide a wider holding area. FIGS. 17( a ) through 17( d ) are various views of a fourth example of a grapple-type tractor attachment that may be constructed using kit 51 , the grapple-type tractor attachment of FIGS. 17( a ) through 17( d ) being represented generally by reference numeral 701 . Tractor attachment 701 may differ from tractor attachment 401 in that support units 57 - 1 and 57 - 2 of attachment 401 may be replaced with clamping units 55 - 2 and 55 - 3 , respectively. As compared to tractor attachments 401 , 501 , and 601 , tractor attachment 701 may provide greater clamping power, and, as compared to tractor attachment 501 , tractor attachment 701 may provide a wider holding area.
[0106] It is to be understood that other combinations of the components of kit 51 are possible and that all such combinations come within the scope of the present invention.
[0107] Referring now to FIGS. 18( a ) through 18( d ) , there are shown various views of one possible use to which tractor attachment 401 may be put, namely, to hold a wooden log L securely in such a manner as to permit the log L to be cut into smaller pieces using, for example, a chainsaw of the like. As can be seen best in FIG. 18( a ) , tractor attachment 401 may have an overall length l 2 that may be, for example, approximately 48 inches, and clamping unit 55 - 1 may be spaced apart from each of support units 57 - 1 and 57 - 2 by a distance d 1 that may be, for example, approximately 3 inches. Consequently, by cutting the log L at opposite ends of tractor attachment 401 , for example, along imaginary lines 751 and 753 shown in FIG. 18( a ) , one may obtain a log of approximately 48 inches, which may be a suitable length if the log is to be used as firewood for a typical outdoor wood boiler. Moreover, by additionally cutting the thus-cut log approximately midway between clamping unit 55 - 1 and support unit 57 - 1 , for example, along imaginary line 755 shown in FIG. 18( a ) , and approximately midway between clamping unit 55 - 1 and support unit 57 - 2 , for example, along imaginary line 757 shown in FIG. 18( a ) , one may obtain three logs of approximately 16 inches each, which may be a suitable length if the logs are to be used as firewood for a typical interior wood stove.
[0108] As noted above, the spacing between neighboring clamping unit(s) 55 and/or support unit(s) 57 on mounting assembly 53 may be varied simply by positioning the neighboring clamping unit(s) 55 and/or support unit(s) 57 at desired locations along rails 61 - 1 and 61 - 2 and preferably then securing the clamping unit(s) 55 and/or support unit(s) 57 in place using locking members 59 . Referring now to FIGS. 19( a ) through 19( c ) , tractor attachment 401 is shown with the side members of support units 57 - 1 and 57 - 2 positioned flush against the side members of clamping unit 55 - 1 . As noted above, the capability to position the side members of support units 57 - 1 and 57 - 2 flush against the side members of clamping unit 55 - 1 may be attributable, at least in part, to the fact that holes 325 and 327 of support units 57 - 1 and 57 - 2 may be appropriately dimensioned to permit the outside ends of pivot assemblies 125 - 1 and 125 - 2 to pass therethrough. If desired, bolts or other fasteners (not shown) may be used to couple support units 57 - 1 and 57 - 2 to clamping unit 55 - 1 to increase the rigidity of the structure.
[0109] Kit 51 may further comprise additional components that may be used in conjunction with mounting assembly 53 to provide alternative tractor attachments that are not of a grapple variety. For example, FIGS. 20( a ) through 20( c ) are various views of a forklift-type tractor attachment 801 . Attachment 801 may comprise a pair of forklift tines 803 - 1 and 803 - 2 that may be removably mounted on mounting assembly 53 . FIGS. 21( a ) through 21( d ) are various views of a snow plow adapter attachment 851 . Attachment 851 may comprise an adapter 853 that may be removably mounted on mounting assembly 53 . FIGS. 22( a ) through 22( d ) are various views of a ball mount adapter attachment 901 . Attachment 901 may comprise an adapter 903 that may be removably mounted on mounting assembly 53 . Accordingly, kit 51 may include one or more of forklift tines 803 - 1 and 803 - 2 , adapter 853 and adapter 903 .
[0110] The various tractor attachments described above are designed to be used in connection with a loader boom on which mounting assembly 53 can be mounted, an example of such a loader boom being loader boom 17 . However, as can readily be appreciated, one may replace mounting assembly 53 with an alternative mounting assembly to permit the tractor attachment to be attached to other types of loader booms. All such alternative mounting assemblies for use with alternative loader booms are intended to come within the scope of the present invention.
[0111] For example, referring now to FIGS. 23( a ) through 23( f ) , there are shown various views of one such alternative mounting assembly to mounting assembly 53 , the alternative mounting assembly being represented generally by reference number 953 . Mounting assembly 953 , which may be used with, for example, loader boom 35 (as seen in FIG. 3( b ) ), may be similar in many respects to mounting assembly 953 . For example, mounting assembly 953 , like mounting assembly 53 , may comprise rails 61 - 1 and 61 - 2 . On the other hand, mounting assembly 953 may differ from mounting assembly 53 in that, whereas mounting assembly 53 may comprise mounting brackets 63 - 1 and 63 - 2 , mounting assembly 953 may instead comprise mounting brackets 955 - 1 and 955 - 2 . Brackets 955 - 1 and 955 - 2 , which are preferably made of a high strength steel or other similarly suitable material, may be arranged generally parallel to one another and generally perpendicularly relative to each of rails 61 - 1 and 61 - 2 . Bracket 955 - 1 may be shaped to include a support 957 - 1 , a plurality of tubular guides 959 - 1 through 959 - 4 , and a block 961 - 1 . In a similar fashion, bracket 955 - 2 may be shaped to include a support 957 - 2 , a plurality of tubular guides 959 - 5 through 959 - 8 , and a block 961 - 2 . Brackets 955 - 1 and 955 - 2 may be adapted to receive the front ends of loader boom 35 (loader boom 35 being shown in FIG. 3( b ) ). Pin 39 - 1 of loader boom 35 may be inserted through guide 959 - 1 of mounting assembly 953 , through plates 41 - 1 and 41 - 2 of loader boom 35 , and through guide 959 - 2 of mounting assembly 953 . Pin 39 - 2 of loader boom 35 may be inserted through guide 959 - 5 of mounting assembly 953 , through plates 41 - 3 and 41 - 4 of loader boom 35 , and through guide 959 - 6 of mounting assembly 953 . Pin 39 - 3 of loader boom 35 may be inserted through guide 959 - 3 of mounting assembly 953 , through end 45 - 1 of loader boom 35 , and through guide 959 - 4 of mounting assembly 953 . Pin 39 - 4 of loader boom 35 may be inserted through guide 959 - 7 of mounting assembly 953 , through end 45 - 2 of loader boom 35 , and through guide 959 - 8 of mounting assembly 953 . Guides 959 - 1 , 959 - 3 , 959 - 5 and 959 - 7 may be provided with transverse openings 971 - 1 through 971 - 4 , respectively, for use in receiving fasteners 47 - 1 , 47 - 3 , 47 - 2 , and 47 - 4 , respectively, of loader boom 35 .
[0112] For example, referring now to FIGS. 24( a ) through 24( c ) , there are shown various views of a second alternative mounting assembly to mounting assembly 53 , the second alternative mounting assembly being represented generally by reference number 973 . Mounting assembly 973 , which may be used with, for example, another conventional loader boom (not shown), may be similar in many respects to mounting assemblies 53 and 953 . For example, mounting assembly 973 , like mounting assemblies 53 and 953 , may comprise a rail 61 - 1 comprising a rear portion 65 and a front portion 67 and a rail 61 - 2 comprising a rear portion 73 and a front portion 75 . On the other hand, mounting assembly 973 may differ from mounting assemblies 53 and 953 in that, whereas mounting assembly 53 may comprise mounting brackets 63 - 1 and 63 - 2 and whereas mounting assembly 953 may comprise mounting brackets 955 - 1 and 955 - 2 , mounting assembly 973 may comprise mounting brackets 975 - 1 and 975 - 2 . Brackets 975 - 1 and 975 - 2 are preferably made of a high strength steel or other similarly suitable material. Bracket 975 - 1 may comprise an outside side member 977 - 1 , an inside side member 977 - 2 , and a rear member 977 - 3 . Bracket 975 - 2 , which may be a mirror image of bracket 975 - 1 , may comprise an outside side member 979 - 1 , an inside side member 979 - 2 , and a rear member 979 - 3 . Brackets 975 - 1 and 975 - 2 are adapted to be mounted on the front ends of a corresponding loader boom (not shown).
[0113] As can be appreciated, while the various different types of tractor attachments described above have been discussed in the context of a common kit, such as kit 51 , from which any of these tractor attachments may be derived, it is to be understood that such tractor attachments need not be derived from a kit capable of making more than one type of tractor attachment and, instead, could be made from a starter kit consisting of, for example, a mounting assembly 53 (or a mounting assembly 953 ) and a single clamping unit 55 or 56 (and, optionally, one or more locking members 59 ). As can be appreciated, the design of the present tractor attachment kit permits clamping unit 55 (or clamping unit 56 ) and support units 57 to be arranged in various different combinations and permits the tractor attachment to be assembled and disassembled easily to facilitate transport and storage. In addition, the design of the present tractor kit permits an owner to purchase, relatively inexpensively, a starter kit with a minimal number of components and to add components as budget allows.
[0114] In view of the above, one of the desirable features of the present invention is its modular design. Existing grapples are built as one solid continuous unit that weighs several hundred pounds and consumes a large storage space. By contrast, as a result of the design of the present invention, the grapple-type tractor attachment of the present invention can be made as several components that can be stored, transported and used independently of one another. Additionally, because of the modular design of the present invention, these components of the attachment can be combined in different ways, depending on the needs of the user. Moreover, the spacing between neighboring units can be adjusted, if desired, so that, for example, neighboring clamping and support units are either substantially flush with one another or spaced apart by a short distance, such as a few inches.
[0115] Another desirable feature of the present invention is that the clamping unit can be used in either of two different modes, a first mode having a greater clamping force but slower closing speed or a second mode having a lesser clamping force but faster closing speed. By contrast, existing grapples have only a single clamping force and closing speed.
[0116] Yet another desirable feature of the present invention is the provision of one or more fangs on the upper jaw of the clamping unit, which one or more fangs may be removably mounted.
[0117] Still another desirable feature of the present invention is the design of the locking member.
[0118] A further desirable feature of the present invention is that the mounting assembly of the grapple-type tractor attachment can also be used with other types of attachment structures, such as forklift tines, a plow adapter, a trailer receiver, and the like, to provide other types of tractor attachment functionalities.
[0119] The embodiments of the present invention described above are intended to be merely exemplary and those skilled in the art shall be able to make numerous variations and modifications to it without departing from the spirit of the present invention. All such variations and modifications are intended to be within the scope of the present invention.
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A tractor attachment mountable on a loader boom of a tractor and a tractor attachment kit. In one embodiment, the tractor attachment is a grapple assembly, and the grapple assembly kit includes a mounting assembly, a plurality of clamping units, and a plurality of support units. The clamping units and the support units are removably mountable on the mounting assembly and may be arranged in different combinations on the mounting assembly. Such combinations may range from a single clamping unit mounted on the mounting assembly to a mixture of clamping units and support units mounted on the mounting assembly to several clamping units mounted on the mounting assembly. The clamping units may have alternative pivot points to permit jaws of the clamping unit to close at different speeds and with different forces. One or more fangs may be removably mounted on a clamping unit to enhance its grip.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of optical imaging and more particularly to reduction of the peak power and speckle contrast for bright field and dark field inspection applications.
[0003] 2. Description of the Related Art
[0004] Many optical systems are designed to produce images such as an inspection system for a partially fabricated integrated circuit or a photomask. Techniques and apparatus for inspecting circuits or photomasks are well known in the art and are embodied in various commercial products such as many of those available from KLA-Tencor Corporation of San Jose, Calif. Most optical imaging systems use a continuous illumination source. However, many times pulsed illumination sources are preferred or are the only sources available. This is especially true in the DUV spectral region below 250 nm where very few high brightness illumination sources exist that are not pulsed. Common examples are excimer lasers used in the photolithography process for manufacturing semiconductor devices.
[0005] If a pulsed illumination source is used, the optical imaging system must contend with the nature of pulsed illumination. This is especially true when inspecting integrated circuits or photomasks. Pulsed illumination typically suffers from two major problems. First, the peak power of the illumination transmitted from the illumination source can be very high and potentially damage elements in the optical system or the object being inspected. Second, the light energy can suffer from “speckle” or random intensity distribution of light due to interference effects. This is especially true for laser light sources.
[0006] Further, instances occur wherein a higher repetition rate source is not available. A system or device for turning a high repetition rate laser, such as a mode locked laser, into a virtually continuous source would be very useful in these situations.
[0007] One prior apparatus for reducing the peak power of a pulsed laser is U.S. Pat. No. 5,309,456 by Horton. The Horton design uses one mirror and one beamsplitter to split a single laser pulse into multiple pulses. The multiple pulses are then delayed with respect to each other using reflective optical delay schemes. Several drawbacks exist for this approach. First, the pulse-to-pulse uniformity is highly dependent on the quality of the mirror and beamsplitter used to form the multiple pulses as well as losses in the optical delay schemes. To maintain uniform pulses this system requires 100% reflective mirrors, 50% reflective and 50% transmissive beam splatters with no absorption, and perfect AR coatings with 100% transmission. Any deviations from this will cause an energy variation between the pulses. For example, consider the effects of imperfect optics on a system that generates 16 pulses. If the beamsplitter transmission is 49% and the reflectivity is 51%, the energy variation between the pulses will be 16%. In addition, if the mirror has a reflectivity of 99% it will cause an additional energy variation between the pulses of 3%. Another limitation of the Horton design is that it is not well suited for the DUV-VUV spectral range. Reflective coatings are much less efficient in this range and can cause large losses. These losses will contribute to pulse-to-pulse nonuniformity and a reduction in the efficiency of the peak power reduction scheme. For example, a reflective optical delay scheme with a 1 m long cavity, using mirrors with 99% reflectivity, and an optical delay of 10 meters will have a loss of 10%. Similarily, a reflective optical delay scheme with an optical delay of 20 m, 40 m, and 80 m will have losses of 18%, 33%, and 55% respectively. If these delay paths are used in a system to generate 16 pulses, assuming perfect 50% beam splitters and a perfectly reflecting mirror, the lowest energy pulse will be only 22% of the highest energy pulse. An additional limitation of the Horton design is that it uses a single mirror and beamsplitter to generate the multiple pulses. This optical setup is not flexible and inhibits compensation of different losses for each delay path. In addition, this scheme offers no solution for dealing with the effects of speckle.
[0008] With respect to speckle problems, two primary techniques have been used in the past to reduce the contrast of speckle in a single laser pulse. The first technique employs two rotating diffusers to create multiple speckle patterns during a single pulse. This technique relies on the relative motion of the two rotating diffusers to produce uncorrrelated speckle patterns. This technique has several major disadvantages. First, the diffusers must rotate at a high at a high rate of speed to produce smoothing within a pulse. For a typical pulse of 20 ns, only a limited number of uncorrelated speckle patterns can be produced. Also, losses from diffusers are typically very high. A typical transmission for such a diffuser is 40%. The diffusers in combination then have a transmission of only 16%. In addition, rotating diffusers can be a source of vibration that can effect the image quality of the system. The second technique uses two diffraction gratings and an electro-optic modulator to produce speckle smoothing within a single pulse. This scheme was developed to minimize speckle problems for laser fusion systems. This technique has several limitations including large size and very high cost. In addition, electro optic modulators operating at high bandwidths in the DUV and VUV ranges are not available.
[0009] It is therefore an object of the current invention to provide a system or arrangement that can reduce the peak power of a laser pulse emanating from an energy source.
[0010] It is another object of the current invention to provide an illumination solution that does not suffer excessive losses due to mirrors, beamsplitters, and optical delay lines but that can produce substantially uniform pulses.
[0011] It is a further object of the current invention to provide an illumination solution that can be readily reconfigured while producing optical delays with minimum optical losses, particularly in the DUV-VUV spectral region.
[0012] It is still a further object of the current invention to provide an illumination solution, having reduced speckle contrast for a single energy pulse.
[0013] It is yet a further object of the current invention to provide for speckle contrast reduction in an illumination system preferably employing a pulsed illumination source wherein said speckle contrast reduction may be employed in combination with other speckle reduction schemes to further reduce the speckle contrast of a single pulse.
[0014] It is yet another object of the current invention to effectively increase the repetition rate of a pulsed source and further to achieve quasi-continuous operation from a high repetition rate source.
SUMMARY OF THE INVENTION
[0015] The present invention is a system and method for reducing the peak power of a laser pulse. The system and method disclosed herein utilize multiple paths using a unique design to divide a pulse received from a light generating device, such as a laser, into multiple lower energy pulses, and delay those pulses such that theymay strike the target surface at different times. The design provided herein comprises a plurality of beamsplitters combined with a plurality of delay elements to delay a pulse or pulses transmitted from the light emitting device in an advantageous manner. The design provides the ability to readily divide the pulse into two, four, eight, or conceivably any number of components with components delayed relative to one another. The energy in each pulse can be adjusted using a variety of optical attenuation schemes to produce pulses with substantially uniform energies. Energy received from the light generating device may be split into components using beamsplitters and directed through different paths toward the target, such as a semiconductor wafer surface. Certain optical delay arrangements using prisms, Brewster's angle surfaces, and reflecting devices employing mirrors or Total Internal Reflection (TIR) surfaces provide delay compensation for the optical paths. These delay schemes can be in classical arrangements such as a White Cell or Herriott Cell or other novel delay schemes described herein.
[0016] The system and method further include a design for reducing speckle contrast, wherein a similar arrangement to that presented for the peak power reduction is employed, using beamsplitters, mirrors, and optical delay arrangements, to reduce the contrast of speckle in a single laser pulse. The reduction in contrast is performed based on the fact that laser beams entering a diffuser at a different angle or position produces a changed speckle pattern leaving the diffuser. Multiple speckle patterns may therefore be generated by multiple beams operating at multiple angles or positions through a diffuser, and the speckle patterns may be integrated together to reduce contrast. However, the speckle pattern must arrive at the detector at slightly different times. Thus the design presented herein to reduce peak power may be used with altered angles between the optical paths such that the split or divided light energy components strike the diffuser at suitably different angles.
[0017] An alternate embodiment for reducing speckle contrast is disclosed wherein a single pulse is passed in an angular orientation through a grating to create a delayed portion of the pulse relative to the leading edge of the pulse. One side of the pulse is delayed with respect to the other side of the pulse. If this time delay is suitably longer than the coherence length of the laser pulse, multiple zones are created across the pulse that will not interfere. Each of these zones can then pass through a diffuser at different angles and the speckle contrast can be reduced. A second grating can also be used in combination with the first grating to remove the spectral dispersion while maintaining the optical delay from one side of the pulse to the other.
[0018] In addition, these techniques to reduce the speckle contrast can be used in combination with other speckle reduction techniques to further reduce the speckle. Two examples of such techniques are a light pipe and a lens array. A light pipe or lens array spatially divides an input beam into multiple beamlets. Each of these beamlets then overlaps at the output of the light pipe or lens array. If the spatial or temporal coherence of the input pulse is sufficient so that one beamlet does not interfere with another, speckle contrast can be reduced.
[0019] Further, the method described herein for creating multiple pulses from a single pulse effectively increases the repetition rate of a repetitively pulsed source. The method described herein for reducing the speckle contrast from a single pulse using a grating to delay one side of a pulse with respect to the other side effectively increases the pulse length in time. Using both of these techniques in combination may produce a continuous or nearly continuous source from a high repetition rate source.
[0020] These and other objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 illustrates an embodiment of the design used to reduce the peak power of a laser pulse, and one that can be altered by varying the angles of the components to reduce speckle contrast for a single laser pulse;
[0022] FIG. 2 a shows a plot of the intensity of a single pulse;
[0023] FIG. 2 b is a plot of the intensity of multiple pulses, specifically eight pulses, resulting from the use of the system and method similar to the one illustrated in FIG. 1 ;
[0024] FIG. 3 is a delay arrangement using two prisms, each prism including a TIR surface and an AR surface;
[0025] FIG. 4 illustrates two prisms rotated such that light energy entering makes a total of six round trips between prisms, thereby increasing overall delay time;
[0026] FIG. 5 a is a delay arrangement employing a single image relay lens;
[0027] FIG. 5 b illustrates a delay arrangement having two image relay lenses;
[0028] FIG. 6 presents a delay arrangement wherein three prisms are used each having a TIR surface and incorporating a Brewster's angle surface;
[0029] FIG. 7 is a preferred angular arrangement of pulses to apply to ground glass to reduce speckle contrast in accordance with the invention herein and the design of FIG. 1 ;
[0030] FIG. 8 shows the results of a standard laser pulse, the use of two DUV pulses, and four DUV pulses and the associated speckle contrasts;
[0031] FIG. 9 is an alternate embodiment of the method and apparatus for reducing speckle contrast employing a diffraction grating;
[0032] FIG. 10 is the resultant speckle contrast of the grating arrangement used in FIG. 9 ; and
[0033] FIG. 11 illustrates a functional diagram of the elements used in a device that reduces peak power and speckle contrast.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The present invention is a system and method for reducing peak power and speckle contrast in an imaging system employing a pulsed illumination source. The system uses multiple beam splitters in an arrangement that has the ability in many environments to minimize the energy variation between pulses. This system allows for a flexible setup where various combinations of plate beamsplitters and cube beamsplitters in different arrangements and geometries may be used while still within the scope of the teachings of the current invention.
[0035] In typical pulsed illumination source inspection systems, optical delay lines can be a major source of losses. The losses in the delay arms result from imperfect optics such as mirrors having less than 100% reflectivity, beamsplitters with loss and unequal beamsplit ratios, absorption of light energy in glass materials and coatings, and light energy scattering effects. These optical delay line losses adversely contribute to variations in the pulse-to-pulse energy unless a method of compensation is used. In the present invention, components are introduced between the beamsplitters to compensate for losses in the beamsplitters, mirrors, and optical delay lines. The net result is that the pulse energies are much more uniform. High efficiency within the system minimizes the required introduction of compensating losses.
[0036] A schematic of an embodiment of a scheme to generate four pulses is shown in FIG. 1 . From FIG. 1 , light energy is initially generated by light emission source 101 . The light energy is shown as four separate beams to more clearly illustrate the formation of four separate pulses. In most real situations only a single light beam would originate from the light source. The light energy from light emission source 101 is a pulsed light source. Light is transmitted toward beamsplitter 102 , which splits the light energy. The pulse that is reflectedby beamsplitter 101 is directed to the 10 ns optical delay 103 , and beamsplitter 104 Beamsplitter 104 may again either split the beam or permit the beam to pass through. If it passes through, it is directed to the 20 ns optical delay 105 , mirror 106 , and to the specimen. In the case of the pulsed light energy passing through beamsplitter 102 , said light energy contacts loss compensator 107 and subsequently passes to beamsplitter 104 . Loss compensator 107 compensates for imperfect optical components such as the beamsplitter 102 or loss in optical delay 103 In this manner, light energy reflected by beamsplitter 102 contacts beamsplitter 104 at the same or nearly the sameenergy as light energy passing through beamsplitter 102 and loss compensator 107 . Similarly, light energy from beamsplitter 104 that passes through loss compensator 108 strikes the sample surface at approximately the same energy as light passing the 20 ns optical delay 105 and mirror 108 . If the light from source 101 is polarized, mirror 108 , could be replaced by a waveplate and polarizing beamsplitter. In this manner the beams can be easily co-aligned. This mechanization provides for varying delays of the pulsed light energy such that light energy strikes the specimen surface at a desired time with relatively uniform energies.
[0037] The design presented in FIG. 1 generates four pulses each delayed by a different amount of time. The pulse passing directly through both beamsplitters has no delay introduced, while deflecting off both beamsplitters introduces a 10 nanosecond delay. 20 and 30 nanosecond delays can also be introduced in this arrangement as shown. This introduction of delay reduces the peak power of the pulses contacting the specimen surface.
[0038] The effects of using a design similar to the one illustrated in FIG. 1 are illustrated in FIGS. 2 a and 2 b . The system used to generate the pulses in FIG. 2 b is capable of producing eight pulses delayed by varying amounts of time. In FIG. 2 a , a 532 nm laser pulse is delivered to the specimen surface. The magnitude of the energy striking the surface is 100 per cent. FIG. 2 b shows the multiple pulses delivered to the surface, wherein the spacing between pulses is 14.2 nanoseconds, and eight pulses are delivered in 100 nanoseconds. The magnitude of the pulses delivered is on the order of 12.5 per cent. Thus rather than exposing the surface with a single large energy pulse, the surface is contacted by multiple smaller pulses.
[0039] A scheme to create multiple pulses from a single pulse poses problems with producing a uniform energy for the multiple pulses. This is especially true when a large number of pulses or long delays are required. In addition, maintaining uniform pulse amplitudes is further complicated in the UV-DUV portion of the spectrum. Optical losses tend to be very high because of increased absorption, less efficient AR and HR coatings, and increased scattering. However, even efficient optical systems can still suffer significant differences in pulse energies. In this scheme, compensators are used to add additional losses, similar to those produced by the beamsplitters, mirrors, optical delay lines, and so forth, in order to make the pulse energy uniform.
[0040] Many different schemes can be used for compensation. A common technique is to use attenuation in the form of reflective or absorbing filters. The appropriate filters can be used to compensate for the losses and make the pulse energies uniform. Continuously variable filters are available that allow exact matching. In addition, other techniques can be used, such as employing a polarization based attenuator when using polarized light.
[0041] The optical delay line is an important component of the present system. Imaging relays or stable optical cavities are preferred because they maintain the beam profile and stability over long optical delay paths. Many of these schemes are commonly known in the industry. Reflective cavities such as White cells, Herriott cells, or other reflective multipass cells are typical examples. One major problem with these type of multipass cells is they can be very inefficient. If long optical delays are necessary, many cavity round trips will be required with many mirror reflections. In the DUV-VUV spectral range, where mirror coatings may not be highly reflective, the efficiency of an all reflective optical delay line may be unacceptable. For this reason it is desirable to employ optical delay schemes that minimize losses.
[0042] In the DUV-VUV spectral region, antireflection coatings are typically more efficient than HR coatings. In addition, interfaces at Brewster's angle and TIR surfaces can have extremely low loss. The present design allows the use of novel optical delay schemes that can utilize Brewsters angle surfaces, TIR surfaces and transmissive surfaces that can be AR coated to greatly enhance the efficiency of the optical delay scheme. One such novel optical delay scheme utilizing these types of surfaces is illustrated in FIG. 3 . The system of FIG. 3 utilizes two prisms, left prism 301 right prism 302 , having total internal reflections and an AR coated surface as an optical delay mechanism. This arrangement has the additional advantage that the optical delay can be tuned simply by rotating the prisms about their common axis. From FIG. 3 , the light beam is introduced into the arrangement and is deflected by a mirror 306 to left prism 301 , which directs light outward toward right prism 302 . Right prism 302 has two TIR (total internal reflection) surfaces 303 and an AR (anti-reflective) surface 304 for directing the beam back toward left prism 301 . After a single pass through the arrangement, light energy exits the arrangement, shown as the output beam in FIG. 3 , using mirror 305 to direct the light energy outward. Additional methods can be used to direct the input and output beams. Examples of these methods include a single mirror using the front surface for the input and the rear surface for the output, or a prism using TIR and AR surfaces in much the same manner as prism 301 and 302 . In addition, the input and output beams can be located in a variety of positions within the cavity to suit the particular application. This produces the necessary delay for the system in an efficient manner. As may be appreciated, the desired time of the delay directly affects the spacing between the various components.
[0043] Further delays may be obtained by creating multiple trips between the reflecting surfaces prior to passing the light energy out of the arrangement. The increase in delay by rotation of the left prism 301 and right prism 302 are shown in FIG. 4 . The arrangement shown in FIG. 4 has the limitation that the beam is not re-imaged as it passes back and forth between the prisms. An image relay can be added to the arrangement of FIG. 4 by placing a lens or lenses between the prisms. Addition of a lens or lenses provides for re-imaging such that an image may be retrieved and processed at varying points in the design, thus providing increased control over the quality of the image received. An imaging relay can be inserted in the optical delay arrangement as shown in FIG. 5 a . This optical delay improves the stability and maintain the beam size for long optical delays. An image relay example using two lenses in an afocal telescope arrangement is shown in FIG. 5 b . Alternately, one or more prism surface can be curved to act as a lens, in the case of an AR surface, or a curved mirror, in the case of a TIR surface, for purposes of re-imaging the light.
[0044] Novel optical delay schemes utilizing TIR and Brewster's angle surfaces are also possible. One such optical delay geometry is shown in FIG. 6 . From FIG. 6 , input beam 601 is directed into the arrangement and redirected using a mirror 602 toward first prism 603 . First prism 603 directs the received beam toward second prism 604 , which directs the beam toward third prism 605 . Each prism has a TIR surface and two Brewster angle surfaces to efficiently deflect and transmit the light energy. Once light energy is reflected by third prism 605 , it is output as output beam 607 from the arrangement using a mirror 606 . A lens or lenses can also be added to this geometry to re-image the light, either in the path of the light or at the entrance or exit of one of the prisms. Multiple round trips can be achieved by providing a small angle of the beam out of the plane of the drawing in FIG. 6 . This will cause the beam to walk down the surfaces of the prisms with each round trip.
[0045] The system further includes the ability to reduce speckle effects in transmitted and received light. It can be shown that when a laser beam enters a diffuser at a different angle, the speckle pattern of the light energy leaving the diffuser also changes. This change in speckle pattern for different angles enables generation of multiple speckle patterns by multiple beams at multiple angles when light energy passes through a diffuser. These speckle patterns can be integrated together to reduce the speckle contrast. However, in order for integration to function properly, each speckle pattern must arrive at the detector at slightly different times. Varying arrival times of speckle patterns can be achieved by using the same optical apparatus previously described to reduce the peak power of a laser pulse. The optical apparatus, such as that illustrated in FIG. 1 , generates multiple pulses separated in time from a single input pulse.
[0046] The difference between using the system illustrated in FIG. 1 for reducing peak power and using the system to reduce speckle contrast is the alignment of the optical apparatus. Typically, when multiple pulses are generated to reduce the peak power of a single pulse, all the optical paths are co-aligned to have the same optical axis and the same beam position at the exit of the optical apparatus. However, for reducing the speckle contrast, it is desirable to have different angles between the different optical paths. Different angles are achieved by slightly changing the angles of the mirrors and beamsplitters in the optical apparatus. This angular change produces different angles between each output pulse as the pulse exits the optical apparatus and enters the diffuser as shown in FIG. 7 . The result of using two and four pulses to reduce the contrast of a speckle pattern is shown in FIG. 8 . From FIG. 8 , a typical DUV laser arrangement without the implementation of FIG. 1 having varying angles between optical paths produces a speckle contrast of 80 per cent. Use of the implementation of FIG. 1 may entail, for example in a 2 DUV beam arrangement, light energy being directed through the beamsplitters and loss compensators for one channel, i.e. the 0 ns loss leg of FIG. 1 , as well as the 10 ns path. Such an implementation requires redirecting at least one path of light energy, such as the energy emitting from the 10 ns delay path, so as to contact the surface at an angle different from the 0 ns energy path in a manner as demonstrated in FIG. 7 , i.e. at an offset angle from the 0 ns path. Using this type of implementation, speckle contrast may be reduced to on the order of 56 per cent. Use of four separate and summed DUV beams, such as all four paths illustrated in FIG. 1 , reduces the speckle contrast to on the order of 40 per cent.
[0047] One problem with this scheme is that diffusers are not efficient. In the arrangement illustrated in FIG. 1 , a phase plate may be inserted in the system instead of a diffuser to increase efficiencies. Phase plates with multiple levels or continuous profiles can provide efficiencies approaching 100%.
[0048] The second method for reducing speckle contrast using a single pulse employs a grating to produce an optical delay from one side of the pulse to the other. The use of a grating to delay a portion of the pulse is illustrated in FIG. 9 . Grating 901 causes one side of the laser wavefront to be delayed in time. This delay caused by grating 901 changes across the beam making the wavefront tilt in time. In FIG. 9 , the wave emanates from the light generating device (not shown) at the bottom of the illustration. The pulse has a diameter D and in the arrangement shown the left portion of the beam strikes the grating 901 and is redirected by the grating 901 before the right half of the pulse strikes the grating. The distance covered in a fixed period of time is the same for the right and left side of the pulse, and thus by the time the right side of the pulse reaches location 902 , the left side of the pulse has reached location 903 . From the illustration, the right side of the pulse covers an additional distance L before striking grating 901 . The illustration shows an approximate 45 degree angle between the pulse and grating 901 , but in practice other angles could be employed while still within the scope of the invention. In the illustrated 45 degree angle case, the right side of the pulse covers a distance that is ultimately 2L shorter than the distance covered by the left side of the pulse. This differential in time or in distance covered produces a differential akin to the delay produced by the implementation of FIG. 1 . The resultant tilted wavefront can be used in combination with a diffuser or phase plate to reduce the speckle contrast.
[0049] From FIG. 9 , the initial laser pulse will have a well defined coherence length. After the pulse passes through grating 901 one side of the pulse is delayed and the coherence length remains the same. The right side of the pulse is delayed with respect to the left side by:
Delay=2L=2D tan θ i
[0050] where D is the diameter of the input beam and θ i is the diffraction angle. This mechanization effectively breaks up the pulse into many independent sections that do not interfere with each other. These independent sections combine in intensity to reduce the speckle contrast. The number of independent sections is equal to:
Sections = 2 L l c
[0051] where 2L is the maximum delay and l c is the coherence length. The result of the use of a grating such as that presented in FIG. 9 to reduce the contrast of a speckle pattern in shown in FIG. 10 . From FIG. 10 , speckle contrast may be reduced from 80 per cent for a single pulse to 29 per cent using a grating as shown in FIG. 9 .
[0052] Speckle reduction techniques using the implementation of FIG. 1 and that of FIG. 8 may be used in combination to further reduce speckle contrast. In addition, the use of optical delays and gratings or other redirectional or delaying elements can be used in combination with a light pipe or lens array to produce an ideal uniform illumination source with low peak power and low speckle contrast. FIG. 11 illustrates the operation and elements in a system for reducing speckle contrast. Step 1101 involves generating the initial laser pulse. Step 1102 provides for tilting the pulse using a grating such as: the grating 901 presented in FIG. 9 . Step 1103 comprises splitting the pulse received from the grating and delaying the pulse using multiple exit angles. Step 1104 indicates passage of the varying angle and delayed pulses through ground glass or phase plates and subsequently passing the received light energy to a light pipe or lens array in step 1105 . Other combinations of the pulse delay or dividing and combining techniques disclosed herein are possible while still within the course and scope of the invention.
[0053] The system and method described for creating multiple pulses from a single pulse effectively increases the repetition rate of a repetitively pulsed source. For example, if a 2 kHz excimer laser is used in combination with the system designed to create four pulses as described in FIG. 1 , the repetition rate is increased to 8 kHz. In addition, the system and method described for reducing the speckle contrast from a single pulse using a grating to delay one side of a pulse with respect to the other side effectively increases the pulse length in time. It is therefore conceivable that by using both of these techniques in combination, a continuous or nearly continuous source can be produced from a high repetition rate source. To illustrate this, assume a laser operating at 80 MHz with a 100 ps pulse width is used in combination with a system, similar to that described in FIG. 1 , designed to create 32 pulses with the appropriate delays, the repetition rate is effectively increased to 2.6 GHz. The pulse separation of the 2.6 GHz source is around 400 ps. Now if the 100 ps pulse can be stretched to 400 ps, the source can be considered continuous. Using a grating at a symmetric 45 degree angle, the 100 ps pulse can be stretched to 400 ps using a beam 2.4 inches in diameter. One potential problem with this approach is the spectral dispersion created by the grating. This can be eliminated by adding a second grating. This second grating eliminates the spectral dispersion while maintaining the optical delay from one side of the pulse to the other.
[0054] While the invention has been described in connection with specific embodiments thereof, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses or adaptations of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as come within known and customary practice within the art to which the invention pertains.
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A system and method for reducing peak power of a laser pulse and reducing speckle contrast of a single pulse comprises a plurality of beamsplitters, mirrors and delay elements oriented to split and delay a pulse or pulses transmitted from a light emitting device. The design provides the ability to readily divide the pulse into multiple pulses by delaying the components relative to one another. Reduction of speckle contrast entails using the same or similar components to the power reduction design, reoriented to orient received energy such that the angles between the optical paths are altered such that the split or divided light energy components strike the target at different angles or different positions. An alternate embodiment for reducing speckle contrast is disclosed wherein a single pulse is passed in an angular orientation through a grating to create a delayed portion of the pulse relative to the leading edge of the pulse.
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This application is a continuation of application Ser. No. 08/100,938, filed on Aug. 3, 1993 now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to methods for transmitting digital information between a main unit and a number of subunits of an electrical device, and preferably to a method for transmitting digital information between a main unit and subunits of a modular programmable controller. The method of the present invention transmits digital information via a serial bus system having at least one data line for transmitting the information, one timing line for specifying a shared system clock, and at least one control line for transmitting control signals. In the method of the present invention, at least the data line may run through the subunits so that the bus system is operable as a shift register having a total register length equal to the sum of individual register lengths of the subunits. The present invention also relates generally to electrical devices for implementing the method.
German 36 03 751 A1 discloses a method for transmitting digital information between a main unit and a number of subunits. The method applied therein for transmitting information via a circulating register is not yet quite optimal, since in order to transmit the information, the entire register must always be cleared, and the register lengths of the individual modules or peripheral units must be definitively preset. Thus, when information is supposed to be transmitted, for example, to only one of the peripheral units, a great deal of blank information must be transmitted along with it. This reduces the theoretically attainable speed of information transmission.
The present invention is directed to the problem of developing a method for transmission of digital information over a serial bus system, which is designed as a shift register, yet which method operates as flexibly, efficiently, and almost as user-friendly as a parallel bus system.
SUMMARY OF THE INVENTION
The present invention solves this problem by transmitting both commands and data within the information, and when data are transmitted, by adjusting the individual register lengths of the subunits in dependence upon the last transmitted command. Analogously, the subunits of the electrical unit have bus interface connections, whose individual register lengths are variable.
A serial-parallel conversion of the transmitted or to-be-transmitted information takes place advantageously in the subunits and in the main unit. For this purpose, the bus interface connections have serial-parallel converters.
The bus system preferably has at least one additional control line, so that the subunits can differentiate between command and data transmissions. This makes it possible, namely, for all subunits to simultaneously receive and evaluate a command when it is transmitted. This considerably increases the efficiency of the information transmission.
The efficiency can be enhanced further when one single subunit reacts to one part of the commands, so-called single commands, and when several, especially all, of the peripheral subunits react to another part of the commands, the so-called group commands.
The information transmission method is especially fail-safe when a frame mark is able to be transmitted along with the information transmissions, making it possible to detect transmission errors. A frame mark should always be transmitted along with the transmission of commands, especially along with the transmission of single commands.
It is particularly simple and user-friendly to initially operate and restart the device when the main unit automatically determines the number, and in some instances, the grouping of the peripheral subunits at start-up, as well as automatically identifies and parameterizes the subunits.
To increase the efficiency of the bus system, the individual register lengths should not only be dependent upon the commands, but also upon the subunits.
When the minimal individual register lengths of the subunits are zero, the bus system can not only be operated as a shift register, but also as a serial bus. The possible individual register lengths are preferably 0 bit, 1 bit, and integral multiples of 8 bits.
The reliability of the information transmission is enhanced further when the bus system has at least one acknowledgement line to transmit acknowledge signals from the subunits to the main unit. This allows the subunits to acknowledge information transmitted via the bus.
When the bus system additionally has an alarm line to signal alarms triggered by the subunits to the main unit, the subunits are able to be designed with alarm capability.
The bus system can be terminated by the bus interface connections when in addition to the data line, the control line is also run through the bus interface connections. Preferably, the timing line, as well as in some instances other control lines, such as the alarm line and the acknowledgement line can also be run through the bus interface connections. In this manner, it is possible to devise separate bus systems, which are independent of one another, within the same electrical device, and thus to create parallel processing possibilities and/or hierarchically structured systems. Therefore, not only can the main unit be a central processing unit, but an intelligent peripheral module as well, which, in turn, has its own bus segment having several allocated or allocatable subunits. As a rule, the subunits are peripheral modules.
When the bus system has a release line, by means of which the outputs of output units are able to be coupled into or rather separated from the bus system, the possibility of blocking the outputs during critical operating states is able to be realized, as known from programmable controllers having a parallel bus. The release circuit is conducted through the bus interface connection only in the case of units which can terminate the bus system, so that the release or blocking signal transmitted via the release circuit is able to be received simultaneously by all output units of the electrical device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a block diagram of a programmable controller.
FIG. 2 depicts the bus system of a programmable controller.
FIG. 3 depicts an alternate embodiment of the programmable controller.
FIG. 4 depicts the essential structure of the bus interface connections.
FIGS. 5 and 6 depict the command structure.
FIG. 7 depicts a partial structure of the programmable controller.
DETAILED DESCRIPTION
In accordance with FIG. 1, the maximum structure of a modular electrical device, in this case a programmable controller, consists of a central processing unit 1 and four groups or strands 2-5. Each strand 2-5 consists of an interface unit 6 and eight peripheral units 7. The peripheral units 7 are also described in the following as modules. Addresses 0 through 7 are always allocated to modules 7 of strand 2; addresses 8 through 15 to those of strand 3, etc. With respect to the mechanical-design structure of the programmable controller and of the bus system, reference is made to U.S. patent application Ser. No. 07/923,286, which was filed on Jul. 31, 1992, the subject matter of which is hereby incorporated by reference.
The interface units 6 are interconnected via multicore cables 8. The cables 8 can be up to 20 meters long, thus making it possible for a distributed system to be realized.
The programmable controller is supplied with power strand by strand. Thus, each strand 2-5 has its own power supply SV. The power supply SV, as depicted in FIG. 1, is preferably integrated in the interface units 6, or rather in the central processing unit 1. Preferably, the interface unit 6 of strand 2 is also integrated in the central processing unit 1.
The communication between the central processing unit 1 and the peripheral units 7 takes place via a bus system, whose structure is clarified in the following in conjunction with FIG. 2.
FIG. 2 shows a seven line bus system for the programmable controller. They are the data line 9, the timing line 10, the control lines 11, 12, the acknowledgement line 13, the alarm line 14, and the release line 15.
Lines 9 through 15 have the following functions:
Commands are transmitted via the data line 9 by the central processing unit 1 to the modules 7. Furthermore, data are transmitted via the data line 9 from the central processing unit 1 to the modules 7 and vice versa. Therefore, the data line 9 is a bidirectional data line.
The timing line 10 transmits a clock signal, which determines the speed of the serial information transmission via the data line 9.
The momentary bus state is established by means of the control lines 11 and 12. If both lines 11, 12 are carrying a high signal, then the bus is in the free-circuit condition. If the control line 11 goes to low, then this indicates the beginning of a command transmission. If the control line 12 goes to low, then this indicates the beginning of a data transmission. If both control lines 11, 12 go to low, then all bus interface connections 17 of the entire programmable controller are reset.
The modules 7 communicate the transfer of commands or data, or rather indicate the end of a data transmission via the acknowledgement line 13.
The modules 7 can request an alarm processing through the central processing unit 1 by way of the alarm line 14.
The outputs of output units are coupled into or rather separated from the bus system by means of the release circuit 15. The outputs are separated from the bus system, at the moment that the signals transmitted via the release circuit 15 goes to low. The release circuit 15 is preferably conducted through the bus interface connection 17 only in the case of functional modules and central subunits. In this manner, it is possible namely for the signal being transmitted via the release circuit 15 to be received simultaneously, and without a time delay, by all modules 7 that are linked to the release circuit 15.
The bus system of the programmable controller is obviously a serial bus system. Therefore, the processor 16 of the central processing unit 1 preferably has a standard, serial interface, to which at least the data line 9 is conducted. A parallel processing of the data takes place, of course, in the processor 16. Consequently, the processor 16 always undertakes a serial-parallel conversion when inputting or outputting data.
The peripheral units 7 are linked via bus interface connections 17 to the bus system. The bus interface connections 17 are preferably Application Specific Integrated Circuits (ASICs). A serial-parallel conversion of the transmitted or to-be-transmitted data takes place in these bus interface connections 17, in the same way as in the processor 16 of the central processing unit 1. The ASICs 17 are preferably integral components of the module parts, as described in the U.S. patent application Ser. No. 07/923,286, already referred to in conjunction with FIG. 1.
Lines 9 through 14 are run through the bus interface connections 17. This makes it possible, for example, for the bus interface connection 17 of the middle one of the three modules depicted in FIG. 2 to terminate, or rather separate the bus system, although this module 7 is not the last module of the strand in question. It will be clarified in greater detail in conjunction with FIG. 3, in which cases it is effective for the bus system to be terminated or separated.
FIG. 3 shows a possible configuration of the programmable controller, where it would be practical for there to be a separation of the bus system. In accordance with FIG. 3, the programmable controller consists of the central processing unit 1, the interface units 6, the modules 7, the functional module 18, the modules 18', and the central subunit 19. The functional module 18 and the central subunit 19 have the following mode of operation:
The functional module 18 is an intelligent peripheral unit, which can run a small subprocess independently. An example of a functional module is a controller module. To be able to affect the process and to acquire knowledge about it, outputs and inputs must, of course, be available and be able to be accessed by the functional module 18. The modules 18' arranged to the right of the functional module 18 are provided for this purpose.
It is evident that the exchange of information can take place between the functional module 18 and the modules 18' independently of the information exchange between the remaining parts of the programmable controller. Therefore, the functional module 18 is able to separate the bus system and to operate a separate, local bus segment. The size of this bus segment is determined by the fact that the sum of the modules 7 upstream from the functional module 18, the functional module 18, and the modules 18' downstream from the functional module 18 must not exceed the maximum number of modules per strand, in this case eight plus the interface unit.
The functional module 18 does not separate the bus system already at the time of start-up of the programmable controller, but rather only after it has received the command or rather release message for this from the central processing unit 1. Therefore, before receiving the release message, the central processing unit 1 can access the modules 18'. In contrast to this, the central subunit 19 always separates the bus system. The central processing unit 1 only knows that the central subunit 19 is present. The central processing unit 1 does not know the expansion level of the subsystem having the central subunit 19. In contrast to the functional module 18, the central subunit 19 has its own power supply SV, so that the power supply of the particular strand of peripheral units 7 will not be overloaded by the subsystem, which itself can have a system expansion of up to four interface units 19' and 32 modules 19".
Of course, one central subunit 19 or one functional module 18 can be arranged in each strand 2-5 of peripheral units 7. In the same way, such functional modules 18 and central subunits 19 can also be arranged in the subsystem, whose central processing unit represents the central subunit 19. Thus, one is able to design hierarchically structured systems with expanded computing capacity.
The inner structure of the bus interface connections 17 is depicted in a simplified version in FIG. 4. FIG. 4 thereby shows only those parts of the bus interface connection 17 which are important for the understanding of the present invention. In accordance with FIG. 4, the data line 9 is conducted in the bus interface connections 17 via two semiconductor multi-circuit switches 20, in the following also called multiplexers 20. By means of the multiplexers 20, it is established whether and, in some instances, which of the registers 21 through 26 is switched into the data line 9. If none of the registers 21 through 26 is switched into the data line 9, then in case of data transmissions, the data line 9 is short-circuited via line 28. When commands are transmitted, the multiplexers 20 connect the data line 9 to line 29. In this manner, it is possible to load the transmitted command into the 16-bit shift register 27 and, on the other hand, to simultaneously relay it to the next bus interface connection 17.
The multiplexers 20 are always controlled in the same manner. They are triggered by the evaluating logic 30. When the evaluating logic 30 learns by way of the control line 11 that next a command will be transmitted, then line 29 is always selected. If, on the other hand, the control line 12 goes to low, then one of the other data paths 21 through 26, 28 is activated. The evaluating logic 30 decides which of the other data paths 21 through 26, 28 will be activated on the basis of the last command that was transmitted and stored in the register 27. Of course, the evaluating logic 30 also evaluates its knowledge of the module 7, in which the bus interface connection 17 is situated. This knowledge is filed, for example, in the memory unit 31. Alternatively, it is also possible, of course, for the evaluation unit 30 to be programmed accordingly or hardware-wired.
The evaluating logic 30 is, of course, also connected to registers 21 through 26, so that it is able to read data out of these registers, or rather store data in these registers. During these restoring operations, a serial-parallel conversion is undertaken, inter alia. However, the corresponding interconnected wiring configurations are not shown in FIG. 4 for the sake of clarity.
The setting of the multiplexers 20 does not change for as long as a new command is not transmitted. To transmit information via the bus system, commands and data are alternately transmitted via the data line 9.
When data or commands are transmitted, the command-control line 11 or the data-control line 12 initially go to low. The information transmission then begins after a short delay of approximately one clock cycle. At the end of the information transmission, the triggered control line 11 or 12 again goes to high. As a result, the modules 7 retrieve the transmitted information and apply a low signal to their acknowledgement circuit 13. As a result, the central processing unit 1 knows that the information transmission was successfully concluded. If the check-back signal from the modules 7 does not follow within a preset delay of, for example, 500 nanoseconds, then this is interpreted as a transmission error, and the transmission is repeated.
As mentioned above, the peripheral units 7, 18, 18', 19, as well as the interface units 6 evaluate transmitted commands and react to specific commands. There are
commands, which all modules 7 of the programmable controller, in some instances also all interface units 6, react to;
commands, which all or a part of the modules 7 of a strand 2-5, in some instances also the interface unit 6 of this strand, react to; and
commands, which only one single module 7 reacts to.
In the following, the latter commands are called individual commands, the others group commands.
FIG. 5 depicts the structure of a group command. According to FIG. 5, a group command has the length of 1 byte or 8 bits. Bit D15 thereby establishes whether it is a question of a read command or a write command. Bit D14 must be zero, since it is used to distinguish between individual commands (when bit D14 has the value 1) and group commands (when bit D14 has the value zero). Bits D13 and D12 establish which of the four strands 2-5 of the programmable controller should be accessed. Bits D11 through D8 determine the command to be executed, for example the reading or writing of the process image.
Since the "reading" or "writing" function is already established by bit D15, 32 different commands can be realized altogether. Examples of such commands are "read in process image inputs", "read out process image outputs" and "read bus expansion".
FIG. 6 shows the structure of one individual command. The significance of bits D15 through D12 was already described for the group command. Bits D11 through D9 establish which module 7 of the selected strand 2-5 is supposed to be accessed. Bits D8 through D1 define this access in detail. The information of bit D15 is again evaluated, in addition, here as well. It establishes whether it is a question of a read or a write access. Typical commands are, for example, the "write data block" or "read data block" command, the releasing of a bus segment for a functional module, or byte/word/double-word accesses, or the alarm acknowledgement.
Bit D0 is always zero. This allows the modules 7 to recognize faulty command transmissions. In principle, such an error recognition is also possible for group commands. In this case, however, group commands having a full 16-bit length would also have to be transmitted. Bits D7 through D1 would then be insignificant. Bit D0 again has the value zero as a frame mark bit. Optionally, bit D0 can also be a parity bit.
When group commands are transmitted in a short form, i.e., with an 8-bit length, a limited error recognition is likewise still possible. When the command-control line 11 goes to low, all bits D0 through D15 of the command register 27 are set, namely, to one, with the exception of bit D8. Bit D8 is set to zero by the evaluating logic 30. When a group command is transmitted via the data line 9, the value of bit D0 is a zero after an 8-bit data transmission. It can thus be controlled whether a correct number of bits, namely 8, were transmitted.
Several typical command/data transmissions will now be described by way of example in the following. To clarify these command/data transmissions, reference is made to FIG. 7. In accordance with FIG. 7, the strand 2 of the programmable controller consists of the interface unit 6 and of several modules 32 through 36.
Module 32 is a 16-bit digital-input module. Module 33 is a 16-bit digital-output module. Module 34 is an 8-bit digital-input module. Module 35 is an 8-bit digital-output module. Module 36 is a functional module.
When the programmable controller is started up, the command "read in expansion level" is initially output for strand 2. The command "read in expansion level" is a group command, which acts on the selected strand, in this case strand 2. The result of this command is that in each existing module of strand 2, the shift register 26 is switched with the value zero into the data line 9.
Since the data line 9 on the side of the bus interface connections 17 facing away from the central processing unit 1 is connected via pull resistors 37 to the supply voltage, a zero bit is in fact output by the last module 36 as a message for its own module 36. However, after that, 1-bits are always passed on. The reason for this is that the pull resistor 37 of this module 36 always retains the data line 9 on the side facing away from the central processing unit 1 at one.
The central processing unit 1 reads in one word, i.e., 16 bits, from the strand 2 in question. The number of input zero bits indicates the number of peripheral units of the strand 2. The interface unit 6 is also included in the count for this number as a peripheral unit for reading the expansion level.
On the basis of the above described determination of the expansion level, the central processing unit 1 knows that five modules 32 through 36 and the interface unit 6 are connected to it in the given exemplified embodiment in strand 2. This information, namely six linked units, is already utilized at the time the next command is executed by the central processing unit 1.
To identify the units that are linked to the central processing unit 1, the type identifier of the peripheral units is determined for each strand, thus in the given example for strand 2. For this purpose, the central processing unit 1 outputs the group command, "transmit type identifier" for strand 2, and then reads in two bytes as data per peripheral unit, thus in the present case, 12 bytes. The modules 32 through 36 and the interface unit 6 switch their bus interface connections 17 so as to allow the 16-bit shift register 24 to be read out. The type identifier, which is stored with remanence (i.e., residual induction) in each unit in a type-identifier register, had been previously stored in this register 24. Stored in the type-identifier registers of the units is information pertaining to how large the address spaces for inputs and outputs are, and which type of module is involved (for example, interface unit, analog input module, digital output module, etc.).
Next, the central processing unit 1 parameterizes modules 32 through 36. Up until now, the individual modules 7 did not know, for example, in which module slot they were arranged, thus which address was assigned to them.
To parameterize the individual modules, the central processing unit 1 outputs the group command "retrieve parameters" for strand 2. It then outputs two bytes per module as data. The data are again passed through the 16-bit shift register 24 into the bus interface connections 17 and retrieved into modules 32 through 36 by means of serial-parallel conversion after the data transmission ends. The transmitted parameters comprise at least the addresses under which the modules 32 through 36 are later addressable, as well as one bit, indicating whether these addresses are valid. Furthermore, still other parameters are specified for modules 32 through 36, for example whether they have alarm capability, whether they are supposed to output or input a frame mark bit along with the process image transfer, and how they are supposed to perform in case of a blocking of the release circuit 15.
In contrast to the reading in of the expansion level and transmission of the type identifier, the interface unit 6 switches through the data line 9 when modules 32 through 36 are parameterized. The reason for this is that the interface units 6 are self-addressing. When an interface unit is newly added to the system, it immediately signals this to the interface unit 6, which is connected to it in incoming circuit. It then learns of its configuration in the programmable controller from this interface unit 6. Thus, from the time contact is made with the series-connected interface unit 6, the interface unit 6 knows whether the strand address 00 2 (for strand 2), 01 2 (for strand 3), 10 2 (for strand 4) or 11 2 (for strand 5) is assigned to it.
The programmable controller is automatically configured, as described above in conjunction with FIG. 7, for all strands 2-5 in sequence. After the device has completed its run-up, the central processing unit 1 knows, as a result, the number and grouping of the peripheral units 6, 7, 18, 19, 32 through 36 linked to it.
After start-up of the programmable controller, as described above, normal operation follows with process image transfer, process alarms, alarm processing, analog input/output, etc. The process image transfer of the inputs and outputs is described by way of example in the following.
Two digital input modules, namely module 32 and module 34, are arranged in strand 2 of the programmable controller in the example illustrated in FIG. 7. The module 32 has 16 inputs, module 34 has eight. The central processing unit 1 is aware of this factual situation on the basis of the start-up of the unit, as described above.
After transmission of the group command, "read in process image inputs", module 32 has queried the data to be read into the central processing unit 1 from its process inputs and stored it in the 16-bit shift register 24. Analogously, module 34 has stored its input data in the 8-bit shift register 25.
After the appropriate command is entered, the central processing unit 1 begins to read in the data. While the data are read into the central processing unit 1, modules 32, 34 connect their shift register into data line 9. The other modules 33, 35, 36 switch through data line 9. Thus, only the digital-input modules 32, 34 react as strand 2 to the command, "read in process image inputs". The data that have been input into the central processing unit 1 are, therefore, without exception, useful data, since the modules 33, 35, 36 without digital inputs do not feed data into the data line 9. Therefore, the central processing unit 1 inputs only three bytes of data, namely two bytes for the module 32 and 1 byte for module 34. Of course, the same procedure also takes place for strands 3 through 5.
The process image transfer takes place analogously for the outputs. Here as well, on the basis of the preceding identification run, the central processing unit 1 knows the configuration of strands 2-5 and, therefore, knows how large the data length to be output is. The digital output modules 33, 35 connect their shift register with 8, 16, or 32 bits (depending upon the number of output channels) into the data line 9, the other modules 32, 34, 36 switch through data line 9. Therefore, when the process image transfer of the outputs takes place, only useful data are transmitted, no blank data. Here, as well, all strands 2 through 5 are operated one after another.
Modules 32 through 35 are parameterizable to such an extent that they transmit or receive a frame mark during the process image transfer. During the process image transfer, the frame mark consists of one byte having a preset bit pattern. When the inputs are read into the central processing unit 1, this byte is compared to the specified bit pattern. Conversely, when the process outputs are read out, the byte received by modules 33, 35 is checked for the specified bit pattern. This frame mark makes it possible for transmission errors to be detected.
When, along with this, modules 32 through 35 feed in or query their frame mark byte, the data transmission takes place via registers which are 8 bits longer than inputs/outputs on the modules. Thus, for example, during the process image transfer of the inputs, a 16-bit-digital input module transmits 24 bits, namely 16 bits of useful data plus 1 byte frame mark.
To clarify the alarm processing, the assumption is made in the following that the functional module 36 is a limit monitoring indicator, thus a module, which signals when [values] exceed or fall below a limiting value.
When the signal to be monitored comes into a critical range, module 36 transmits an alarm via alarm circuit 14 to the central processing unit 1. Initially, the central processing unit 1 does not know which module has triggered the alarm and what kind of alarm it is. Therefore, the central processing unit 1 outputs the command, "read in alarms". Each module of the operated strand switches its 1-bit register 26 into data line 9. If the module 32 through 36 in question has not triggered any alarm, then its data bit has the value one, otherwise zero.
The central processing unit 1 reads in 1 byte and, in this manner, can determine which module has released an alarm.
The central processing unit 1 then outputs the group command, "read in alarm types". The modules, which have triggered an alarm then switch their 8-bit register 25 into data line 9. The other modules switch through data line 9.
The types of alarms pending at the modules had been stored beforehand in register 25 by the modules triggering the alarm. Thus, by evaluating the inputted bytes, the central processing unit can determine which alarms are present at which module. The sequence of the alarm processing and, thus, also the priority of the alarms is not yet established. It is able to be specified by the program, perhaps even by the user. Examples of possible alarms are process alarms and diagnostic alarms.
Process alarms are alarms which are triggered by input modules, when these modules are fed input signals, which require an immediate reaction from the central processing unit 1.
Diagnostic alarms are triggered when the modules establish on the basis of the self-monitoring properties that there must be malfunctions within the module, or rather in their circuit wiring to the process.
In the case of diagnostic alarms and also during parameterization of functional modules, larger quantities of data must sometimes be transmitted. For this, the programmable controller knows the individual commands, "load data block beginning address and length" and "write data block" or "read data block".
A single module is addressed by means of the command "load data block starting address and length". As a result, this module, for example the functional module 36, switches its register 24 into the data line 9. The central processing unit then transmits 16 bits. On the basis of these bits, the functional module 16 knows how many words are supposed to be transmitted and where the initial address of the words to be transmitted lies in the address area of the functional module 36. When the data are transmitted, the other modules 32 through 35 switch through the data line.
The central processing unit 1 then transmits the single command "read data block" or "write data block". A continuous transmission of the data block to be transmitted is then begun. After 16 bits at a time, the functional module 36 accepts the last data word that was read in from the register 24, or rather stores the next data word to be transmitted in register 24. The other modules 32 through 35 switch through the data line during the data transmission.
In addition to the individual commands described above and to group commands acting on a strand 2-5, there are also group commands which act simultaneously on all strands 2-5. An example of such a command is the power-failure warning. When a notch in the supply voltage is detected in the central processing unit 1, then this command is output (preferably as an 8-bit command). Not only is this group command received and evaluated by the modules 7 in all four strands 2-5 independently of the value of bits D13 and D12, but, in addition, all affected modules 7 in all four strands 2-5 react to it. The reaction of the modules 7 can consist, for example, in that important data are written in the EEPROMs, for as long as the supply voltage can still be buffered.
As clarified in detail above on the basis of examples, an efficient programmable controller having a serial backplane bus is made available hereby for the first time. However, the present invention is not limited, of course, to the given exemplified embodiment. Other configurations of the programmable controller, of the bus interface connection, of the command sets and the like are able to be realized without having to digress from the idea of the present invention.
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A modular programmable controller, comprised of a central processing unit and peripheral units, has a serial bus system in the form of a shift register. The total length of the shift register is equal to the sum of the individual register lengths of the bus interface connections of the peripheral units. The individual register lengths of the bus interface connections are dependent upon command and peripheral units. The individual register lengths amount to between 0 and 40 bits. This results in an exceptionally efficient exchange of information between the central processing unit and peripheral units.
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FIELD OF THE INVENTION
This invention relates to a supplemental gas drive and brake device for a Gatling type gun.
BACKGROUND OF THE INVENTION
Gatling type guns, having a plurality of gun barrels disposed in an annular row in a rotor for rotation in a housing, are well known, having been first disclosed in U.S. Pat. No. 36,836 issued Nov. 4, 1862 to R. J. Gatling. The early Gatling guns had manual crank drives. C. J. Ebbets in U.S. Pat. No. 550,262 issued Nov. 26, 1895, and W. E. Simpson in U.S. Pat. No. 598,822 issued Feb. 8, 1898, respectively disclose supplemental gas drives wherein gun gas is bled from a port in the side of each barrel to operate a ratchet drive for the rotor. The modern Gatling gun was first disclosed in U.S. Pat. No. 2,849,921 issued Sept. 2, 1958 to H. Otto which had an electric motor drive.
Muzzle brakes for single barrel guns are also well known and are shown, for example, in U.S. Pat. No. 1,994,458 issued Mar. 19, 1935 to G. M. Barnes; U.S. Pat. No. 2,457,802 issued Jan. 4, 1949 to A. Bauer; and U.S. Pat. No. 2,567,826 issued Sept. 11, 1951 to J. E. Prache.
Muzzle brake torque assist devices for Gatling guns are shown in U.S. Pat. No. 3,703,122 issued Nov. 21, 1972 to D. A. Farrington et al, and U.S. Pat. No. 3,898,910 issued Aug. 12, 1975 to R. T. Groff. These patents respectively disclose a single turbine having a single annular row of curved radial passageways. Since each of the plurality of gun barrels in the rotor respectively provides gas mainly to the adjacent portion or sector of radial passageways; there is a lateral load which must be reacted by the stationary structure at the radius of the turbine outlets to react the force generated at the turbine outlets. The diameter of the single turbine must be larger than the diameter of the annular row of gun barrels, since the outlets of the single turbine are disposed radially outwardly beyond the maximum radius of the row of barrels.
SUMMARY OF THE INVENTION
It is an object of this invention to provide for a Gatling gun a muzzle brake torque assist device without a lateral reaction force applied to the gun mount.
It is another object of this invention to provide for a Gatling gun a muzzle brake torque assist device whose diameter is no greater than the maximum diameter of the barrel cluster of the gun.
A feature of this invention is the provision for a Gatling gun of a muzzle brake torque assist device having a plurality of radial flow turbines, each centered on a respective gun barrel, each turbine for providing a respective pure torque centered on the respective barrel, and which torques translate into a summation torque centered on the longitudinal axis of the cluster of barrels without generating any lateral loads on the stationary portions of the gun.
BRIEF DESCRIPTION OF THE INVENTION
These and other objects, features and advantages of this invention will be apparent from the following specification thereof taken in conjunction with the accompanying drawing in which:
FIG. 1 is a perspective view of a Gatling type gun embodying this invention;
FIG. 2 is a detail perspective view of the muzzle brake torque assist device of FIG. 1;
FIG. 3 is a detail perspective cutaway view of the device of FIG. 2;
FIG. 4 is graph showing the power provided by the device of FIG. 2 for a typical Gatling gun installation;
FIG. 5 is a side elevation of the device of FIG. 2, and
FIG. 6 is a front cross-section taken along the plane VI--VI of FIG. 5.
DESCRIPTION OF THE INVENTION
The Gatling gun shown in FIG. 1 includes a stationary housing 10 which is mounted, as to a vehicle, by a pair of recoil adapters 12. A plurality of gun barrels 14, hereshown as three, are fixed in an annular row to a rotor (not visible) which is journaled for rotation within the housing. The barrels are held in a cluster by a forward barrel clamp 16, a mid-barrel clamp 18 is journaled for rotation in a slide mount 20. A similar type of gun mount is shown in U.S. Pat. No. 4,345,504 issued to R. G. Kirkpatrick et al on Aug. 24, 1982. The gun may be of any suitable Gatling type, as shown, for example in U.S. Pat. No. 4,314,501 issued to R. G. Kirkpatrick on Feb. 9, 1982, or in U.S. Pat. No. 4,216,698 issued to R. E. Chiabrandy on Aug. 12, 1980, or in U.S. Pat. No. 3,760,683 issued to J. M. Seemann on Sept. 25, 1973.
As shown in FIG. 2, the forward barrel clamp 16 serves as part of the muzzle brake torque assist device 22. The device 22 includes a plurality of barrel extension tubes 24, serving as torque tubes, here shown as three, one for each barrel, that are fixed to the clamp 16. Each extension tube has a plurality of radial slots 32 cut through its tube wall, shown as six in FIG. 3, to provide a like plurality of torque tube vanes 28 each having a face 30. However, as shown in FIG. 2, to provide rigidity to the tube structure, each slot is actually formed as a longitudinally extending set of ports 32, each set here shown as three in number.
The muzzle device 22 deflects a large percentage of the muzzle gas from axial flow to radial flow by impact with the aft facing surfaces formed by the plurality of slots. This change in direction of the high-velocity muzzle gas provides a forward thrust on the barrel cluster, to which the muzzle device is attached, which partially counteracts the recoil force. It may be noted that when firing a round of ammunition having a large amount of propellant, the contribution of the propellant gas to the total recoil impulse is nearly half the total. Thus, deflecting the gas radially reduces the average recoil force as well as the peak recoil force.
The radially directed flow of muzzle gas through the ports 32 against the faces 30 of the vanes 28 imparts a torque about the longitudinal axis of the respective gun barrel, shown in FIG. 3 as counter clock-wise when viewed from the rear. These torques about the gun barrel axes resolve into a torque about the longitudinal axis of the gun barrel cluster which is the axis of rotation of the rotor, shown in FIG. 2 as counter clock-wise.
As shown in FIG. 5, the face 30 of the vane 28 is a plane which is tangential to the inner bore 34 of the torque tube.
The outlet cross-sectional area of the port 32 is enlarged by removing part of the back wall at 36.
The outlets of the ports 32 are radially within the radius of the nonrotating slide mount 20, within which the mid-barrel clamp 18 rotates. Since gases flow equally through all slots of the extension tube there is no lateral load which must be reacted by the mount 20 to react the forces generated at the outlets. The radius of the housing 10 is similarly greater than the radius of the outlets.
While the face 30 has been shown as tangential to the inner bore 34, it will be appreciated that the face may be at any angle that will deflect the generally radial flow of gas into a more tangential flow and absorb energy nonsymmetrically from such deflection to generate a torque. As a limiting value, if the port 32 is cut on a true radius to the longitudinal axis of the tube, such energy as will be absorbed, will be absorbed symmetrically, and no torque will be generated. The face 30 may also be formed concave, rather than flat, as shown.
A round of ammunition having a projectile mass of 1600 grains and a propellant mass of 120 grams can generate an impulse per shot of approximately 55 lb.-sec. The muzzle device can reduce this impulse by 30% to 40 lb-sec. per round, and generate 32 H.P. The gun system power requirement (without the muzzle device) as a function of time during system acceleration, is shown in the upper curve of FIG. 4. Note that the required power rises to a peak of 49 H.P. and then declines to 40 H.P. steady state. The gun system power requirement (with the muzzle device) as a function of time during system acceleration, as shown in lower curve of FIG. 4. Note that the required power rises to a peak of merely 26 H.P. and then declines to 8 H.P. steady state. This reduction of the external power requirement allows a broad spectrum of potential power sources to drive the gun: electric, engine bleed air, self-contained pneumatic and hydraulic.
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There is provided for a Gatling type gun, a muzzle brake torque assist device having a plurality of radial flow turbines, each centered on a respective gun barrel of the gun, each turbine for providing a respective pure torque centered on the respective barrel, and which torques translate into a summation torque centered on the longitudinal axis of the cluster of barrels without generating any lateral loads on the stationary portions of the gun.
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FIELD OF APPLICATION OF THE INVENTION
[0001] This invention relates to the field of roofing elements such as those used in low swimming pool shelters and in particular to the adaptations making it possible to improve the transparency and reduce the weight thereof.
DESCRIPTION OF THE PRIOR ART
[0002] The roofing elements can be those proposed in document FR 2776000, which describes a swimming pool roofing element structure of the type composed of a cover formed by panels made of a translucent material such as double-wall polycarbonate and a rigid, lightweight and resistant reinforcement for supporting the transparent cover, which reinforcement is formed by arcs arranged in transverse planes and spaced apart by cross-members with two outermost lateral cross-members delimiting two edges of the roofing element. These two lateral edges rest on the longitudinal edges of the basin defining a contact surface with said roofing elements.
[0003] These roofing elements have the disadvantage of using double-wall alveolar polycarbonate for the translucent panel.
[0004] This alveolar polycarbonate is expensive and does not provide the best possible transparency since it is formed by at least two sheets connected to one another by partitions.
[0005] Moreover, the thickness of such an alveolar material defines a bulk that must be dealt with when transporting said panels.
[0006] The prior art discloses more transparent, non-alveolar materials, but their use presents other problems, for example:
a sheet of solid material of lower thickness is too flexible, a sheet of solid material with the same rigidity as the alveolar material is too heavy.
[0009] Another problem encountered in the exterior use of large panels of a solid material sheet involves the variation of the dimensions to which it can be subjected due to the variation in temperatures.
DESCRIPTION OF THE INVENTION
[0010] On the basis of the above, the applicant has conducted research to find an alternative to the use of alveolar panels in roofing elements.
[0011] This research has resulted in a technical solution making it possible to use panels of more flexible material with a lower thickness, overcoming the disadvantages mentioned above.
[0012] According to the main feature of the invention, the roofing element of the type consisting of a panel of material held inside of a frame is remarkable in that it is composed of a panel made of a single-wall solid material and at least one tensioning means linked to the frame tending to separate certain parts constituting the frame so as to apply tension to said panel,
[0013] the frame is composed of two transverse profiles attached to two opposite sides of the panel, with the tensioning means tending to separate said profiles,
[0014] the edges of the panel subjected to a pulling force and slid into the profiles are equipped with at least one projection facilitating the transmission of this force, with the profile being itself preformed in order to retain this projection in the direction of the pulling force.
[0015] This feature is particularly advantageous in that it makes it possible to use a single-wall panel in spite of its lack of rigidity. It is thus possible to use any material capable of being placed in a frame and capable of supporting the pulling force to which it will be subjected. The tensioning of the panel makes it possible to prevent it from collapsing in the event of dilation due to climatic conditions.
[0016] This feature therefore ensures a panel that perfectly matches the general shape of the frame in spite of its flexibility.
[0017] This feature is possible whether the panel is transparent or not. Indeed, the feature allows the use of perfectly transparent single-wall non-alveolar panels. The transparency of the material used for the panel makes it possible to see through and offers the possibility of seeing inside the basin protected by the roofing, which is particularly secure. This security functionality could not be implemented in the panels of the prior art, which were alveolar and which could not be considered to be translucent.
[0018] The use of a single-wall panel reduces the weight of the structure and requires less bulk for storage or transport.
[0019] Thus a special feature of the invention is the association, with the frame or with the reinforcement supporting the flexible and transparent panel, tensioning means tending to separate certain parts forming the frame in order to maintain the tension of said panel.
[0020] According to another particularly advantageous feature of the invention, this roofing element consists of two transverse profiles attached to two opposite sides of the panel and connected to one another by cross-members of which at least one comprises tensioning means tending to separate said profiles. The tensioning can be performed for each element ensuring the connection between the two profiles, i.e. for each cross-member.
[0021] In the case of a low swimming pool shelter, the profiles into which the panels slide are conventionally arched and form arcs of which each end rests on the edge of the basin. In addition, the two outermost lateral cross-members, which delimit two edges of the roofing element and which rest on the longitudinal edges of the basin, define a contact surface with said roofing elements.
[0022] To transmit and control the pulling force, the edges of the panel subjected to a pulling force, slid into the profiles, are equipped with at least one projection facilitating the transmission of this force. The profile is itself preformed to retain said projection in the direction of the pulling force.
[0023] These tensioning means can be implemented in a plurality of embodiments.
[0024] A first embodiment proposes that at least one end of a cross-member slide transversely with respect to the profile and comprise at least one tensioning means composed of a casing housing a spring that comes into contact with said profile, thus tending to separate the cross-member from the profile.
[0025] A second embodiment proposes that the cross-member equipped with tensioning means consist of two parts capable of being moved one with respect to the other and connected to one another by a sliding connection controlled by a spring.
[0026] According to a preferred technological choice, the material of the single-wall panel is polycarbonate.
[0027] The fundamental concepts of the invention having been described above in their most basic form, other details and features will become clearer on reading the following description and in view of the appended drawings, provided for non-limiting purposes, of an embodiment of a roofing element according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a diagrammatic drawing of a perspective view of an embodiment of a low swimming pool shelter composed of roofing elements according to the invention,
[0029] FIG. 2 is a diagrammatic drawing of a partial cross-section view of a roofing element using a first embodiment of the tensioning means,
[0030] FIG. 2 a is a diagrammatic drawing of a cross-section of a detail of said tensioning means,
[0031] FIG. 3 is a diagrammatic drawing of a partial cross-section view of a roofing element using a second embodiment of the tensioning means.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The drawing of FIG. 1 shows an embodiment of a low swimming pool shelter referenced A in its entirety ensuring the coverage of a basin referenced B. This low shelter includes a plurality of roofing elements E.
[0033] Each roofing element E is composed of a panel of material 100 held inside a frame 200 . This frame 200 is composed of two transverse arched profiles 210 and 220 connected to one another by the panel 100 and by cross-members 230 arranged under the panel 100 . Two outermost lateral cross-members 231 and 232 delimit two edges of the roofing element E. These two lateral edges rest on the longitudinal edges of the basin B defining a contact surface with said roofing elements E.
[0034] The edges of the panel 100 slide into the arched profiles 210 and 220 of the frame 200 and cause the panel 100 to adopt the curvature of said profiles. The cross-members ensure the spacing of said profiles in order to ensure the rigidity thereof.
[0035] According to the invention, the roofing element E includes a panel 100 made of a single-wall solid material and tensioning means connected to the frame tending to apply tension to said panel 100 , which is flexible due to its thickness and size.
[0036] According to a preferred embodiment and according to the invention, the material used is transparent. According to a preferred technological choice, this material is transparent polycarbonate. This polycarbonate is associated with an aluminium frame. The polycarbonate is in the form of a sheet with a thickness of between 1.4 and 2 millimetres, which enables the deformation of its edges, and which provides flexibility enabling it to follow the curvature of the transverse arcs, but which causes a longitudinal bending that must be solved by tensioning means.
[0037] According to the invention, at least one cross-member 230 comprises tensioning means tending to separate said profiles 210 and 220 , which hold the edges of the panel 100 , and therefore tension said panel 100 .
[0038] According to the embodiment shown in the drawings of FIGS. 2 and 3 , the edges of the panel 100 according to the arrows F 1 subjected to a pulling force are equipped with at least one projection facilitating the transmission of this force. More specifically, each panel edge is preformed in order to have a C-shaped edge, which is positioned in the profile 210 and 220 so that its branches come from each side of a lug 211 and 221 provided for this purpose in the profiles 210 and 220 . Thus, once the panel 100 has slid into the profiles, said panel 100 cannot be released from said profiles 210 and 220 in a longitudinal translation movement, i.e. in the direction of the pulling force. The cooperation between this return 110 and the lugs 210 and 220 provided inside the profiles 100 ensures successful transmission of the pulling force exerted by the tensioning means 300 .
[0039] According to the embodiment shown in the drawing of FIG. 2 , at least one end of a cross-member 230 slides transversely according to the double arrow F 2 with respect to one of the profiles 210 and comprises at least one tensioning means 300 composed of a casing 310 housing a spring 320 , which comes into contact with said profile 210 , thus tending to separate the cross-member 230 from the profile 210 .
[0040] More specifically, and according to the invention, said casing 310 adopts the shape of a cylindrical tube, which is attached to the cross-member 230 and at a first end of which a stop 311 is provided, with which the spring 320 comes into contact, and the other end of which is open to enable the spring 320 to come into contact with said profile. According to a particularly advantageous feature, the position of the stop 311 can be adjusted inside the casing 310 so as to ensure the adjustment of the force exerted by the spring. According to a preferred embodiment, said stop 311 is threaded and is connected in a screw-type manner to the casing 310 so as to move axially inside it. The end of the spring 320 that comes into contact with the profile 210 or 220 is associated with a stop 321 .
[0041] According to a preferred embodiment, each cross-member includes means for tensioning the frame. According to a preferred technological choice, the two outermost lateral cross-members 231 and 232 forming edges are equipped with tensioning means 300 and the cross-members 230 between the two outermost cross-members are equipped with two tensioning means 300 .
[0042] An embodiment of the attachment of the two tensioning means at the end of a cross-member 230 is shown in the drawing of FIG. 2 a . In this embodiment, two tubular casings 210 a and 310 b are arranged on each side of the cross-member 230 by being associated with a profile 312 internally including the external profile of the cross-member 230 for its positioning and attachment to the latter. According to a preferred embodiment, the cross-members 230 have a rectangular profile and are slidingly connected at a first end and stationarily connected at the other end to the transverse profiles 210 and 220 , by means of T-shaped parts 400 provided for this purpose.
[0043] According to another embodiment shown in the drawing of FIG. 3 , the cross-member 230 equipped with tensioning means 300 consists of two parts 231 and 232 capable of moving according to the double arrow F 2 , one with respect to the other, and connected to one another by a sliding connection controlled by a spring forming the tensioning means 300 .
[0044] The two ends of the cross-member are then stationarily connected to the transverse profiles 210 and 220 .
[0045] More specifically, said tensioning means 300 consist of a female element 330 associated with a first part 232 of a cross-member 230 cooperating with a male element 340 associated with a second part 231 of the cross-member 230 .
[0046] It is understood that the roofing element has been described and shown above for the purpose of disclosure rather than as a limitation. Of course, various arrangements, modifications and improvements can be made to the example above without going beyond the scope of the invention.
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The invention concerns a roofing element (E) of the type of the one consisting of a material board ( 100 ) maintained inside a frame ( 200 ), characterized in that it consists of a single-walled solid material board and of at least one tensioning means ( 300 ) linked to the frame ( 200 ) tending to space apart certain parts constituting the frame ( 200 ) so as to stress said board ( 100 ), the frame consisting of two transverse profiled sections ( 210 and 220 ) fixed to two opposite sides of the board ( 100 ), the tensioning means ( 300 ) tending to space apart said profiled sections ( 210 and 220 ), the edges of the board ( 100 ) subjected to a tensile stress and slid into the profiled sections being provided with at least one projection ( 110 ) facilitating the transmission of said stress, the profiled section being itself preformed to retain said projection in the direction of the tensile stress. The invention is applicable to swimming pool low shelter, veranda and the like.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to non-destructive testing and, more particularly, to ultrasound inspection of fabricated components.
[0002] Ultrasonic inspection techniques are used in many applications where non-destructive evaluation of a workpiece or component is required. One application of such ultrasonic inspection is in the inspection of gas turbine engine rotors. Such rotors are typically formed from a forging of a material with desired metallurgical properties, for example, Rene-88. In the production of aerospace rotating components, the entire volume of the finished component is required to be inspected ultrasonically. This requires that additional material be present on the forging when it is inspected before machining the finished component. This additional material is referred to as the material envelope and must be equal to or greater than the near surface resolution capability of the ultrasonic inspection process.
[0003] The capability to detect signals from near surface targets, such as flaws and/or discontinuities is a critical to quality feature of an ultrasonic inspection process. A near surface target, as used herein, refers to any target of interest positioned closely to either the front or back surface of the inspection sample. The near surface resolution of a given ultrasonic inspection process, as used herein, refers to the minimum distance from the front (or back) surface of the component to a target that produces an ultrasonic signal that meets the requirements of the inspection process.
[0004] From a component cost perspective, it is important to minimize the material envelope. Due to the high raw material costs for aerospace rotating components, even small reductions in material envelope can have a large impact on component cost. However, known systems are limited in the near surface resolution capability that would permit lessened material envelope requirements.
BRIEF DESCRIPTION OF THE INVENTION
[0005] In one embodiment, a method of fabricating a component is provided. The method includes receiving an ultrasound image of the component, selecting a subimage that includes a first surface of the component and an inspection area of the component, combining a filtered subimage with the selected subimage, and outputting the combined image to at least one of a display and an analyzer.
[0006] In another embodiment, an ultrasound inspection system is provided. The system includes a pulse echo transducer, and a processor operationally coupled to the transducer wherein the processor is programmed to reduce noise in an echo received from a near surface inspection area of a component.
[0007] In yet another embodiment, an ultrasound inspection system is provided. The system includes a pulse echo transducer, and a processor operationally coupled to the transducer wherein the processor is programmed to control said pulse echo transducer during a scan of a component, and receive a plurality of B-scan images from the scan.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic view of an exemplary embodiment of an ultrasound system;
[0009] FIG. 2 is a graph of an exemplary A-scan waveform of a component, such as the component shown in FIG. 1 ; and
[0010] FIG. 3 is a flow chart of an exemplary method for improving near surface resolution of an ultrasound system, such as the ultrasound system shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0011] As used herein, the term “component” may include any component configured to be coupled with a gas turbine engine that may be coated with a wear-resistant coating, for example a turbine shroud support. A turbine shroud support is intended as exemplary only, and thus is not intended to limit in any way the definition and/or meaning of the term “component”. Furthermore, although the invention is described herein in association with a gas turbine engine, and more specifically for use with a rotor for a gas turbine engine, it should be understood that the present invention is applicable to other gas turbine engine stationary components and rotatable components. Accordingly, practice of the present invention is not limited to rotors for a gas turbine engine.
[0012] FIG. 1 is a schematic view of an exemplary embodiment of an ultrasound system 10 that includes a pulse echo transducer 12 coupled to a control unit 14 including a processor 16 , a display 18 , a keyboard 20 and a mouse 22 . As used herein, the term processor is not limited to just those integrated circuits referred to in the art as processors, but broadly refers to computers, processors, microcontrollers, microcomputers, programmable logic controllers, application specific integrated circuits, and other programmable circuits. Control unit 14 is configured to acquire, analyze and display ultrasonic test data. In the exemplary embodiment, ultrasound system 10 is a Pulse echo (PE) ultrasound test apparatus that uses a single transducer located on one side of the component that functions as both a transmitter and a receiver. Using pulse echo testing only requires access to one side of the test component. In various embodiments ultrasound system 10 may include an electromechanical apparatus for moving transducer 12 across the surface of the test component and the electromechanical scanning apparatus may include one or more position sensors that monitor the position of the moving transducer.
[0013] In use, transducer 12 is placed in acoustical conduct with a component 24 to be tested and ultrasound is introduced to component 24 . In one embodiment, a known acoustic gel is placed between component 24 and transducer 12 to facilitate sound transfer between component 24 and transducer 12 . In another embodiment, component 24 and transducer 12 are placed proximate each other submerged in a liquid that facilitates ultrasound wave travel through the liquid. In an exemplary embodiment using the liquid in an automated setting, system 10 includes a rotatable table (not shown) including at least one collet or mandrel (not shown). Component 24 is automatically chucked in the collet or onto the mandrel and the table is rotated or translated such that component 24 remains in close proximity to transducer 12 during a scan. Transducer 12 emits ultrasonic energy which is at least partially reflected when an interface 26 is encountered within component 24 (such as a discontinuity, inclusion or micro-crack) or at an interface on a far side (relative to transducer 12 ) of component 24 between component 24 and the liquid. When the ultrasound wave contacts the interface, a portion of the sound energy is reflected back through the component toward ultrasonic transducer 12 . Ultrasonic transducer 12 may used as both a transmitter that produces RF sound wave pulses and as a receiver that records the reflected RF sound wave signals. The time between when an RF pulse is transmitted and an RF reflection is received equals the time it took for the sound wave to pass into the test component, contact the area of discontinuity, and travel back to the ultrasonic transducer 12 . Thus, the time between transmission and reception is related to the depth of the discontinuity. The amplitude of the RF signal is related to the magnitude of the discontinuity, as the larger the discontinuity, the more sound energy is reflected back towards the ultrasonic transducer 12 . In one embodiment, ultrasonic transducer 12 is located on a mechanical arm (not shown) whose movement is precisely controlled by control unit 14 . The mechanical arm moves the ultrasonic transducer 12 over the surface of test component 24 in a precisely controlled scan during testing. The mechanical arm moves the ultrasonic transducer 12 from a starting point 28 . As ultrasonic transducer 12 moves across test component 24 , ultrasonic test data is taken at preprogrammed data points 30 . In the exemplary embodiment, data points 30 are equally spaced apart a distance 32 . In an alternative embodiment, control unit 14 is programmed to take data at irregular distances. Position sensors (not shown) may be used to facilitate determining a position of ultrasonic transducer 12 during a scan. The position data may then be used to reconstruct test component 24 in ultrasound images.
[0014] As ultrasonic transducer 12 receives the reflected sound waves at an individual data point 30 , the information is passed to control unit 14 in the form of an RF signal. This RF signal is digitized by control unit 14 and the resulting digitized data is passed to and stored as a data array in a memory 34 within control unit 14 . The location on test component 24 from which each set of digitized data originated can be determined by knowing the scan pattern and by knowing the position of the digitized data in the data array.
[0015] FIG. 2 is a graph 200 of an exemplary A-scan waveform 201 of a component, such as component 24 (shown in FIG. 1 ). The digitized RF signal may be displayed as an A-Scan graph of the reflected RF sound energy signal received by ultrasonic transducer 12 wherein time is plotted, for example along an X-axis 202 and amplitude may be plotted along a Y-axis 204 . As described above, the greater the relative size of interface 26 in test component 24 the greater the amplitude of sound energy reflected, thus the greater the amplitude of the RF signal. A front surface echo 206 or first reflection has amplitude that is caused by the front surface of test component 24 . A second and third smaller amplitude reflection 208 and 210 are caused by a reference fault purposefully introduced into component 24 or a discontinuity in an inspection gate area of component 24 . Reflections 208 , and 210 may be voids, delaminations, or other flaws within the test component, or in a component that is made of composite layers, could be the intersections between individual composite layers forming the composite component.
[0016] A near surface resolution of ultrasonic inspection system 10 may generally be controlled by ultrasonic transducer 12 , the control unit 14 used to transmit and receive the ultrasound from transducer 12 , and the signal-to-noise ratio (SNR) required for near surface targets by the inspection procedure. The resolution is typically defined as the difference in amplitude (measured in dB) separating the peak amplitude of the target from the minimum signal amplitude between that peak and the peak amplitude of the front surface signal. The inspection area (or inspection gate) is then set based on the near surface target that produces the amount of dB required by the inspection procedure for near surface resolution. Ultrasound system 10 records an entire ultrasound waveform and stores it for later access. The waveform data can be recorded either for just the inspection area, or a larger area which can include the front and/or back surface reflections. Once the ultrasonic waveform data has been recorded, it is available for post-processing using signal and image processing techniques.
[0017] FIG. 3 is a flow chart of an exemplary method 300 for improving near surface resolution of an ultrasound system, such as ultrasound system 10 (shown in FIG. 1 ). Method 300 facilitates improving near surface resolution by collecting ultrasonic waveform data for the inspection area plus the surface echoes. The algorithm that implements the steps of method 300 may be embodied in a software code segment that is stored in a memory of control unit 14 . The waveform data may be collected over a two-dimensional grid of points on component 24 during an inspection. The waveform data from the area around the surface signals are post-processed using signal and image processing techniques. The result is an improved near surface resolution when compared to the gated maximum amplitude approach. The resulting data can the be further processed for the detection of signals of interest in the inspection either by an automated detection algorithm or by manual review.
[0018] One of a plurality of B-scan images is loaded 302 into a memory of ultrasound inspection system 10 . In the exemplary embodiment, ultrasound inspection system 10 collects a three-dimensional set of data for processing, for example, two spatial dimensions on the surface of the inspection specimen and time in the direction of propagation of the ultrasonic signal. A two-dimensional image in one spatial dimension and time extracted from the 3 D data set may be referred to as a B-scan.
[0019] For each B-scan image, an A-scan waveform is extracted 304 . A position in time of front surface echo 206 for each spatial location is located by processing each waveform (time signal from a single spatial location) individually. The maximum value of the waveform may correspond to the maximum value of the front surface signal. Due to the digitized nature of the front surface waveform, using this maximum value may not consistently define the front surface. Rather, the algorithm uses the maximum value to locate 306 the first time point t h that has an amplitude greater than the half-max value. A numerical derivative of the waveform is taken 308 . The first time point t f in the derivative that is greater than t h and where the value of the derivative is less than zero is located 310 . Point t f is stored 312 as the location of the front surface for that waveform. This process is repeated until the front surface location for all the waveforms in the B-scan image have been determined.
[0020] Alternatively, the front surface locations may be determined by processing b-scan image as a whole. In this method, two-dimensional edge enhancement filters such as Sobel, Robers, Gradiant, Laplacian, Kirsch, Canny, Shen-Castan, or Marr-Hildreth are applied to the image. The edge enhanced images is then post-processed to determine the set of front surface locations t f .
[0021] Using the set of front surface locations t f for the B-scan image, a subimage the contains the front surface echo and the area of interest for inspection after the front surface echo is extracted 314 . In the exemplary embodiment, the algorithm removes the front surface echo from the extracted subimage by, for example, applying background subtraction to create 316 a filtered subimage. After removing the front surface signal, any remaining signals will be due to near surface reflectors. To apply background subtraction, a composite background image is created by filtering the B-scan with a smoothing filter. This filter should smooth the response in the spatial dimension of the B-scan image such that any echoes from near surface targets are suppressed such that they will standout after the future image subtraction step. The filter configuration may be selectable depending on the target component properties, transducer type, and a spatial index. The filtered subimage is subtracted 318 from the extracted subimage to create a processed subimage, which may be stored 320 in a memory of control unit 14 , or other memory or storage device.
[0022] Alternatively, the precise location of the front surface obtained in the points t f , can be used to accurately extract signals a narrow band of time that is a fixed distance from that location without any post-processing such as the background subtraction step described above.
[0023] Method 300 may be repeated 322 for all the B-scans images in the data set. After all the B-scan images have been processed, the processed data set can be further analyzed with the advantage that the near surface targets will have a higher signal-to-noise ratio due to the image processing operations.
[0024] A technical effect of the various embodiments of the systems and methods described herein include at least one of improving the detection of near surface discontinuities in objects being scanned.
[0025] The above-described methods and apparatus are cost-effective and highly reliable for improving near surface resolution of an ultrasound inspection system. The methods and apparatus describe collecting ultrasound waveform data for an inspection area and surface echoes over a two-dimensional grid of points on the component being inspected. The waveform data from the area around the surface signals are post-processed using signal and image processing techniques. The result is an improved near surface resolution. The resulting data can the be further processed for the detection of signals of interest in the inspection either by an automated detection algorithms or by manual review. The methods and apparatus described above facilitate fabrication, assembly, and reducing the maintenance cycle time of components in a cost-effective and reliable manner.
[0026] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
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Methods and apparatus for fabricating a component is provided. The method includes receiving an ultrasound image of the component, selecting a subimage that includes a first surface of the component and an inspection area of the component, combining a filtered subimage with the selected subimage, and outputting the combined image to at least one of a display and an analyzer.
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