description
stringlengths 2.98k
3.35M
| abstract
stringlengths 94
10.6k
| cpc
int64 0
8
|
|---|---|---|
BACKGROUND OF THE INVENTION
A common problem that users encounter when searching for information resources is how to choose keywords for input to a search engine. One particularly perplexing problem occurs when a user wants to search for items for which the user has seen but has no text-based information from which to formulate a search. For example, while browsing the web, a user may see a jacket for which the user wants more information. Unless the jacket is the subject of an advertisement, the user will have great difficulty formulating a query without knowledge of, for example, the manufacturer. Even if the user could identify the manufacturer, searching for additional information about a particular product among similar products offered by that manufacturer can be time-consuming and frustrating. Accordingly, a system and method is needed to solve this problem.
SUMMARY OF THE INVENTION
One embodiment of the present invention is directed to a system for retrieving information. The system comprises a storage unit for storing an image that includes first and second selectable objects. The first selectable object is associated with a first metadata and the second selectable object is associated with a second metadata. The system also includes a visual output device and a processor that communicates with the visual output device and the storage unit to read the first and second metadata. The system also includes a user input device that communicates with the processor and instructs the processor to read the first and second metadata and display the first and second metadata on the visual output device.
DESCRIPTION OF THE FIGURES
For the present invention to be understood clearly and readily practiced, the present invention will be described in conjunction with the following figures, wherein:
FIG. 1 is a functional block diagram of a data processing system for hosting web pages according to one embodiment of the present invention;
FIG. 2 is a functional block diagram of various hardware components of an information processing system used in accordance with one embodiment of the present invention;
FIG. 3 is a combination flow chart and logical block diagram that illustrates the formation of a metadata-enabled image according to one embodiment of the present invention;
FIG. 4 illustrates a web page that includes a metadata-enabled image displayed thereon in accordance with one embodiment of the present invention;
FIG. 5 illustrates a web page that includes discrete selectable objects displayed thereon according to one embodiment of the present invention; and
FIG. 6 is an exemplary flow diagram that illustrates a process in which a user utilizes the present invention to access rich content about an image.
DETAILED DESCRIPTION OF THE INVENTION
It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention while eliminating, for purposes of clarity, other elements. For example, certain details relating to the operation and design of a network capable of carrying hypertext traffic, such as the Internet, the specifications of hypertext protocols, such as HTTP, for use in transporting HTML pages, and the construction of a browser with plug-in extensibility, such as Internet Explorer, are not described herein. Those of ordinary skill in the art will recognize, however, that these and other elements may be desirable in an interactive networked environment. A discussion of such elements is not provided because such elements are well known in the art and because they do not facilitate a better understanding of the present invention.
One embodiment of the present invention relates to a system and method that allow a user of a web browser to select a digitized still image or motion video, or a portion thereof, and automatically formulate a search query for information resources associated with the selected image, video or the selected portion. Accordingly, the term “image,” as used herein, refers to either a still image or a video frame within a stream of video frames. Specifically, the systems and methods described herein relate to images with an enhanced data set referred to as “metadata.” For a general understanding of the features of the present invention, reference is made to the drawings, wherein like reference numerals have been used throughout to identify similar elements.
FIG. 1 illustrates a networked system architecture 100 in which the present invention operates according to one embodiment of the present invention. System 100 includes a client computer 102 connected to a remote server computer 106 over a computer network 108 . Client 102 includes an HTTP browser application program 104 operating thereon, which may be any application program that allows for multimedia presentation of information, including text, images, sound, and video clips such as Netscape Navigator, Microsoft Internet Explorer or an equivalent. System 100 also includes a server 110 , with a metadata editing application program 112 operating thereon, connected to remote server 106 over network 108 . An image database server 114 , also connected to network 108 , stores images or other multimedia files 116 . Metadata editor 112 is an application program designed to attach or otherwise associate metadata to the images 116 . Image database 114 is a any body of information that is organized so that it can be retrieved, stored and searched in a coherent manner by a “database engine”—i.e. a collection of software methods for retrieving or manipulating data in the database. For example, image database server 114 may be a relational, object-oriented, or object-relational database.
It is understood that computer network 100 illustrated in FIG. 1 is exemplary, and alternative configurations may also be used in accordance with the invention. For example, network 108 , as those skilled in the art will understand, may be any suitable computer network including, for example, a metropolitan area network, and/or various “Internet” or IP networks such as the World Wide Web, a private Internet, a secure Internet, a value-added network, a virtual private network, an extranet, or an intranet. Other suitable networks may contain other combinations of servers, clients, and/or peer-to-peer nodes. The present invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
Network 108 may include communications or networking software such as the software available from Novell, Microsoft, Artisoft, and other vendors. A larger network, such as a wide area network (WAN), may combine smaller network(s) and/or devices such as routers and bridges, large or small, and the networks may operate using TCP/IP, SPX, IPX, and other protocols over twisted pair, coaxial, or optical fiber cables, telephone lines, satellites, microwave relays, modulated AC power lines, physical media transfer, and/or other data carrying transmission “wires” known to those of skill in the art. For convenience “wires” includes infrared, radio frequency, and other wireless links or connections.
FIG. 2 is a block diagram that illustrates various hardware components of an information processing system 200 used in accordance with the present invention. Information processing system 200 is representative hardware of client 102 , client 110 , or server 106 . System 200 may be any network-enabled device such as, for example, a personal computer, a programmable digital assistant (PDA), a mainframe, a workstation, a laptop computer, a hand-held computing device, or combinations thereof. System 200 can optionally include, for example, a processing unit 204 , a monitor 206 , and a user interface 208 . Processing unit 204 includes a processor 210 in communication with a memory 212 (shown in phantom) that, in turn, includes a volatile memory 214 and a storage unit 216 . These are representative components of a computer whose operation is well understood.
Processor 210 may include a general purpose device such as an Intel Pentium® processor or other “off-the-shelf” microprocessor. Processor 210 may include a special purpose processing device such as, for example, an ASIC, PAL, PLA, PLD or other customized or programmable device. Memory 212 may include, for example, a static RAM, a dynamic RAM, a flash memory, a ROM, a CD-ROM, a disk, a tape, a magnetic, optical, or another computer storage medium. User interface 208 may include, for example, a keyboard, a mouse, a touch screen, a light pen, a tablet, a microphone, a position sensor, a pressure sensor, a thermal sensor, or other input hardware with accompanying firmware and/or software. Monitor 206 or other type of display device is connected to processor 210 via an interface, such as a video adapter.
System 200 may also include a computer readable medium having executable instructions or data fields stored thereon, such as storage unit 216 . The computer readable medium can be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such a computer readable medium can comprise RAM, ROM, electrically erasable programmable read only memory (EEPROM), CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired executable instructions or data fields and that can be accessed by a general purpose or a special purpose computer.
The computer readable medium tangibly embodies a program, functions, and/or instructions that cause the computer system to operate in a specific and predefined manner as described herein. Those skilled in the art will appreciate, however, that the process described below may be implemented at any level, ranging from hardware to application software and in any appropriate physical location. For example, the present invention may be implemented as software code to be executed by system 200 using any suitable computer language such as, for example, microcode, and may be stored on any of the storage media described above, or can be configured into the logic of system 200 . According to another embodiment, the instructions may be implemented as software code to be executed by system 200 using any suitable computer language such as, for example, Java, Pascal, C++, C, Perl, database languages, APIs, various system-level SDKs, assembly, firmware, microcode, and/or other languages and tools.
FIG. 2 and the foregoing discussion are intended to provide a brief, general description of a suitable computing environment in which the invention may be implemented. Although not required, the invention will be described in the general context of computer-executable instructions, such as program modules, being executed by a personal computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Additionally, those skilled in the art will appreciate that the present invention is not limited to a particular computer system platform, processor, operating system, or network.
FIG. 3 illustrates a process 300 in which metadata editor 112 combines a set of metadata 302 with an image 304 to produce a metadata-enabled image 306 according to an embodiment of the present invention. Metadata editor 112 combines metadata 302 with image 304 using, for example, the Resource Description Framework (RDF) and extensible Markup Language (XML) in a manner known to those skilled in the art. RDF is an interoperable standard for metadata on the web defined by the World Wide Web Consortium (W3C). Document Type Definitions (DTDs) may also be used with XML to create a suitable metadata model. Using these standards, any web image, ranging from gas grills to footwear, can be associated with metadata to conveniently display rich content about the image.
FIG. 4 illustrates a web page 400 that includes metadata-enabled image 306 displayed thereon and in accordance with one embodiment of the present invention. Web page 400 may also display a cursor 402 that may be controlled by user input, as described above. The user may utilize cursor 402 to select an image within web page 400 , such as metadata-enabled image 306 . According to one embodiment, the user positions cursor 402 over metadata-enabled image 306 and clicks on the image 306 using a right-hand button on a pointing device to indicate, for example, a request for context-sensitive action.
According to one embodiment, the context-sensitive action produces a user interface control that may include, for example, a pop-up window having a list of options related to image 306 and its associated metadata 302 . Those of skill in the art will realize that such user interface selection controls may be implemented using, for example, an ActiveX control, a Java control, an applet, or a browser plug-in, or a separate software application. The list of options related to metadata 302 may include, for example, launching a suitable metadata extraction tool to view metadata 302 .
According to another embodiment, the list of options associated with the context sensitive action may include automatically inserting the metadata into a search engine. According to such an embodiment, a search is automatically initiated to locate resources, such as web sites, within a distributed environment. For example, the user may designate a search engine as a user preference before initiating the context-sensitive action. Example of such search engines include Google™, offered by Google of Mountain View, Calif., which may be accessed at the google.com URL and RealPages, offered by BellSouth, which may be accessed at realpages.com URL. Once the user designates the search engine, the present invention may be used to automatically insert metadata 302 into the search engine as search terms. According to one embodiment, the present invention may launch a new browser window that displays the search engine with metadata 302 entered as search terms and allows the user to edit the terms before initiating the search. According to another embodiment, the search is initiated immediately from the context-sensitive action. The search engine examines the search criteria and returns a list of web documents to browser 104 at the client computer 102 that conform to the search criteria and that may be desired by the user.
FIG. 5 illustrates a web page 500 that includes an exemplary metadata-enabled image 502 displayed thereon and in accordance with an embodiment of the present invention. Image 502 includes multiple discrete selectable objects 504 and 506 . Each selectable object has a unique set of metadata associated with it. Accordingly, the user can access metadata associated with any selectable object in the scene. It should be understood that web pages 400 and 500 are merely exemplary of the displays and methods that may be used to select and access metadata associated with an image. Thus, any suitable display and method of displaying images may be used in accordance with the present invention.
FIG. 6 is an exemplary flow diagram that illustrates a process 600 in which a user uses the present invention to access rich content about an image. The process begins at step 602 in which a user at client 102 directs browser 104 to display, for example, web page 500 that includes an image 502 . As explained above, metadata is attached to and/or associated with selectable objects 504 and 506 within the image 502 . To view metadata about object 504 (a woman's jacket), in step 604 , the user clicks on object 504 using, for example, a right-hand button on the pointing device and selects among a list of user options. In step 606 , according to one embodiment, the present invention inserts the metadata associated with selectable object 504 into a predetermined search engine. Finally, in step 608 , according to another embodiment, the present invention automatically initiates the search using metadata as input.
It should be understood that the present invention is not limited by the foregoing description, but embraces all such alterations, modifications, and variations in accordance with the spirit and scope of the appended claims.
|
A system for retrieving information. The system has a storage unit for storing an image that includes first and second selectable objects. The first selectable object is associated with a first metadata and the second selectable object is associated with a second metadata. The system also includes a visual output device and a processor that communicates with the visual output device and the storage unit to read the first and second metadata. The system also includes a user input device that communicates with the processor and instructs the processor to read the first and second metadata and display the first and second metadata on the visual output device.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority from U.S. provisional patent application No. 60/692,112, which was filed on Jun. 20, 2005, and which is incorporated herein by reference in its entirety. This application is a continuation-in-part application of, and claims priority to, U.S. application Ser. No. 11/471,276, filed Jun. 20, 2006, and now allowed, and which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the use of radiofrequency energy to heat heavy crude oil or both heavy crude oil and subsurface water in situ, thereby enhancing the recovery and handling of such oil. The present invention further relates to methods for applying radiofrequency energy to heavy oils in the reservoir to promote in situ upgrading to facilitate recovery. This invention also relates to systems to apply radiofrequency energy to heavy oils in situ.
BACKGROUND OF THE INVENTION
[0003] Heavy crude oil presents problems in oil recovery and production. Crude oils of low API gravity and crude oils having a high pour point present production problems both in and out of the reservoir. Extracting and refining such oils is difficult and expensive. In particular, it is difficult to pump heavy crude oil or move it via pipelines.
[0004] Recovery of heavy crude oils may be enhanced by heating the oil in situ to reduce its viscosity and assist in its movement. The most commonly used process today for enhanced oil recovery is steam injection, where the steam condensation increases the oil temperature and reduces its viscosity. Steam in the temperature range of 150 to 300 degrees Fahrenheit may decrease the heavy oil viscosity by several orders of magnitude. Cyclic steam simulation (CCS) is a method that consists of injecting steam into a well for a period of time and then returning the well to production. A recently developed commercial process for heavy oil recovery is steam assisted gravity drainage (SAGD), which finds its use in high permeability reservoirs such as those encountered in the oil sands of Western Canada. SAGD has resulted recovery of up to 65% of the original oil in places, but requires water processing. All such methods tend to be expensive and require the use of external water sources.
[0005] Other methods in current use do not require the use of water or steam. For example, processes such as the Vapex process, which uses propane gas, and naphtha assisted gravity drainage (NAGD) use solvents to assist in the recovery of heavy crude oils. The drawback to these processes is that the solvents—propane or naphtha—are high value products and must be fully recovered at the end of the process for it to be economical.
[0006] Yet another potential method to enhance the recovery of heavy crude oils is the Toe-To-Heel Injection (THAI) process proposed by the University of Bath. THAI involves both vertical wells and a pair of horizontal wells similar to that used in the SAGD configuration, and uses combustion as the thermal source. Thermal cracking of heavy oil in the porous media is realized, and the high temperature in the mobile oil zone provides efficient thermal sweeping of the lighter oil to the production well.
[0007] Even when they are recovered, heavy crude oils present problems in refinement. Heavy and light crude oil processing will give the same range of refined products but in very different proportions and quantities. Heavy oils give much more vacuum residues than lighter oils. These residues have an API between one and five and very high sulfur and metals content, which makes treatment difficult. Several processes exist to convert vacuum residues. They are thermal, catalytic, chemical, or combinations of these methods. Thermal processes include visbreaking, aquathermolysis and coking.
[0008] Solvent deasphalting (SDA) is a proven process which separates vacuum residues into low metal/carbon deasphalted oil and a heavy pitch containing most of the contaminants, especially metals. Various types of hydrotreating processes have been developed as well. The principle is to lower the carbon to hydrogen ratio by adding hydrogen, catalysis such as tetralin. The goal is to desulfurize and remove nitrogen and heavy metals. These processes may require temperature control, pressure control, and some form of reactor technology such as fixed bed, ebullated bed, or slurry reactor.
[0009] Recent concepts associate different processes to optimize the heavy crude conversion. For example, the combination of hydrotreating and solvent deasphalting in refineries or on site for partial upgrading of heavy crude may be used.
[0010] Finally, the process of gasification for upgrading heavy oil is used. It consists of conversion by partial oxidation of feed, liquid, or solid into synthesis gas in which the major components are hydrogen and carbon monoxide.
[0011] There is a need for an apparatus and method to enhance the recovery of heavy crude oils that does not suffer from the drawbacks associated with current methods. In particular, there is a need for a method that does not use steam or water from external sources, solvents that must be recovered, or combustion. Ideally, such an apparatus and method would at the same time assist in the in situ refinement of the heavy oil.
[0012] The present invention provides just such a method and apparatus. It utilizes radiofrequency energy to combine enhanced oil recovery with physical upgrading of the heavy oil.
BRIEF SUMMARY OF THE INVENTION
[0013] The present invention provides a system and method to apply radiofrequency energy to in-situ heavy crude oil to heat the oil and other materials in its vicinity. This system and method enhance the recovery of the heavy crude oil. At the same time, it may be used to upgrade the heavy crude oil in situ.
[0014] This system enhances the recovery of oil through a thermal method. Heavy crude oils have high viscosities and pour points, making them difficult to recover and transport. Heating the oil, however, lowers the viscosity, pour point, and specific gravity of the oil, rendering it easier to recover and handle. Thus, in the present invention, directed radiofrequency radiation and absorption are used to heat heavy oil and reduce its viscosity, thus enhancing recovery. This dielectric heating also tends to generate fissures and controlled fracture zones in the formation for enhanced permeability and improved flow recovery of fluids and gases.
[0015] The system of the present invention is an in-situ radiofrequency reactor (RFR) to apply radiofrequency energy to heavy crude oil in situ. The RFR incorporates an in-situ configuration of horizontal and vertical wells in a heavy crude oil field. Using these wells, the RFR creates a subterranean reactor for the optimum production and surface recovery of the heavy crude oil. The RFR will provide an oil/hydrocarbon vapor front that will optimize recovery of the oil.
[0016] In it simplest form, the RFR may consist of two wells in the oil field, one a radiofrequency well and the second an oil/gas producing well. At least a portion of both wells are horizontal in the oil field, and the horizontal portion of the radiofrequency well is above the horizontal portion of the oil/gas producing well. A radiofrequency transmission line and antenna are placed in the horizontal radiofrequency well and used to apply radiofrequency energy to the oil, thereby heating it. The resulting reduction in the viscosity of the oil and mild cracking of the oil causes the oil to drain due to gravity. It is then recovered through the horizontal oil/gas producing well. Naturally, any number of radiofrequency and oil/gas producing wells can be used to create an RFR for the recovery of heavy crude oils.
[0017] The invention also has the capability of further enhancing recovery through the directed upgrading of the heavy oil in situ. The horizontal radiofrequency well may be strongly electromagnetically coupled to the horizontal oil/gas producing well so that the temperature of the horizontal oil/gas producing well may be precisely controlled, thereby allowing for upgrading of the heavy oil in the producing well over a wide range of temperatures. The oil/gas producing well may be embedded in a fixed bed of material, such as a catalyst bed, selected to provide upgrading of the crude oil draining from above. The upgrading can be based on several different known technologies, such as visbreaking, coking, aquathermolysis, or catalytic bed reactor technology.
[0018] The present invention has several promising advantages over present methods used to enhance recovery of heavy oil. In particular, the RFR does not require the use of water from external sources. This reduces expense and makes the recovery more economical and efficient. Furthermore, the present invention does not require the use of expensive solvents. Through the use of the present invention, enhanced recovery of heavy crude oil can be achieved more efficiently and cost-effectively.
[0019] Furthermore, in situ processing of crude oil has several advantages over conventional oil surface upgrading technology. First, in situ upgrading can be applied on a well to well basis, so that large volumes of production needed for surface processes are not required. Large, costly pressure vessels are not required since the reservoir formation serves as a reactor vessel. It can be applied in remote locations where a surface refinery would be inappropriate. Some of the required gases and possibly water can be generated in situ by the radiofrequency energy absorption. Finally, full range whole crude oils are treated by RFR and not specific boiling range fractions as is commonly done in refineries. This is made possible by the ability of radiofrequency absorption to provide precise temperature control throughout the reactor volume. The proposed reactor provides large quantities of heat through radiofrequency absorption close to the production well where the catalyst bed is placed. No heat carrying fluids are necessary with radiofrequency heating.
[0020] In one embodiment of the invention, an in situ radiofrequency reactor for use in thermally recovering oil and related materials may be provided. The reactor may comprise at least one radiofrequency heating well in an area in which crude oil exists in the ground, a radiofrequency antenna positioned within each radiofrequency heating well in the vicinity of the crude oil, a cable attached to each radiofrequency antenna to supply radiofrequency energy to such radiofrequency antenna, a radiofrequency generator attached to the cables to generate radiofrequency energy to be supplied to each radiofrequency antenna, and at least one production well in proximity to and below the radiofrequency wells for the collection and recovery of crude oil.
[0021] In another embodiment of the invention, an in situ radiofrequency reactor for use in thermally recovering oil and related materials and refining heavy crude oil in situ may be provided. The reactor may comprise at least one radiofrequency heating well in an area in which crude oil exists in the ground, a radiofrequency antenna positioned within each radiofrequency heating well in the vicinity of the crude oil, a cable attached to each radiofrequency antenna to supply radiofrequency energy to such radiofrequency antenna, a radiofrequency generator attached to the cables to generate radiofrequency energy to be supplied to each radiofrequency antenna, at least one production well in proximity to and below the radiofrequency wells and coupled magnetically to the radiofrequency wells for the collection and recovery of crude oil, and at least one catalytic bed in which the production well is embedded.
[0022] In yet another embodiment of the invention, a method for recovering heavy crude oil is provided. The method comprises the steps of positioning a radiofrequency antenna in a well in the vicinity of heavy crude oil, generating radiofrequency energy, applying the radiofrequency energy to the heavy crude oil with the radiofrequency antenna to heat the oil, and recovering the heavy crude oil through production well.
[0023] In one aspect, in general, a radiofrequency reactor for use in thermally recovering oil and related materials. The radiofrequency reactor includes a radiofrequency antenna configured to be positioned within a well, where the well is provided within an area in which crude oil exists in the ground. The radiofrequency antenna includes a cylindrically-shaped radiating element for radiating radiofrequency energy into the area in which crude oil exists. The cylindrically-shaped radiating element is configured to allow passage of fluids there through. The radiofrequency reactor also includes a radiofrequency generator electrically coupled to the radiofrequency antenna. The radiofrequency reactor is operable to control the radiofrequency energy generated.
[0024] Aspects may include one or more of the following.
[0025] The cylindrically-shaped radiating element in the radiofrequency reactor includes a plurality of apertures for allowing passage of the fluids. In some examples, the plurality of apertures have dimensions selected on the basis of the frequency of the radiofrequency energy.
[0026] The radiofrequency reactor includes a coaxial cable for coupling the radiofrequency antenna to the radiofrequency generator.
[0027] The radiofrequency reactor includes a choke assembly positioned between the radiofrequency antenna and radiofrequency generator to maximize transmission of the radiofrequency energy to the radiofrequency antenna. In some examples, the choke assembly includes an inner conductive casing surrounded by a dielectric portion, the assembly running at least one-quarter of a maximal frequency to be emitted, and the inner casing is connected to a cable for coupling the radiofrequency antenna to the radiofrequency generator.
[0028] The radiofrequency reactor may be one of a plurality of reactors. In such a situation, the radiofrequency generator of each reactor is operable to control the radiofrequency energy generated and is configured to work in conjunction with the radiofrequency generators of the plurality of reactors.
[0029] The radiofrequency generator operable to control the radiofrequency energy generated is configured to control the phase of the radiofrequency energy emitted.
[0030] In another aspect, in general, a method of retrofitting an oil well for extracting crude oil. The method includes electrically coupling a radiofrequency generator to a radiofrequency antenna, where the radiofrequency antenna includes a cylindrically-shaped radiating element for radiating radiofrequency energy into the crude oil. The method also includes controlling the radiofrequency generator to provide radiofrequency energy to the radiofrequency antenna.
[0031] Aspects may include one or more of the following.
[0032] Positioning the radiofrequency generator proximally to the well surface and electrically coupling the radiofrequency generator to the cylindrically-shaped radiating element via a coaxial cable.
[0033] Connecting a choke assembly between the radiofrequency generator and the cylindrically-shaped radiating element.
[0034] Controlling the radiofrequency generator to provide radiofrequency energy to the radiofrequency antenna, including controlling the phasing of the radiofrequency energy emitted.
[0035] While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a perspective view of a basic in situ radiofrequency reactor.
[0037] FIG. 2 is a perspective view of an alternative arrangement of an in situ radiofrequency reactor.
[0038] FIG. 3 is a top view of an arrangement for an in situ radiofrequency reactor for use in large oil fields.
[0039] FIG. 4 is a perspective view of a single borehole radiation type applicator that may be used in the radiofrequency reactor of the present invention.
[0040] FIG. 5 is a diagram of a prior art steam assisted gravity drainage (SAGD) system.
[0041] FIG. 6 is a diagram of a well retrofitted as an in situ radiofrequency reactor.
[0042] FIG. 7 is a diagram of a slotted liner protruding from a well shaft.
DETAILED DESCRIPTION
[0043] A variety of different arrangements of wells and antennae may be employed to apply radiofrequency energy to heavy crude oil in situ, thereby enhancing oil recovery and achieving in situ upgrading of the oil. The proper structure and arrangement for any particular application depends on a variety of factors, including size of field, depth, uniformity, and nature and amount of water and gases in the field.
[0044] FIG. 1 is a perspective view of a basic in situ radiofrequency reactor. Heavy oil is present in oil field 10 . Oil/gas production well 20 is drilled into the oil field for recovery of heavy oil and other materials. At least a portion of oil/gas production well 20 is drilled horizontally through the oil field. Horizontal oil/gas production well 21 is positioned to receive oil and other gas that are moved or generated by the action of the radiofrequency reactor. A second well, radiofrequency well 30 , is drilled into the oil field in proximity to oil/gas production well 20 . At least a portion of radiofrequency well 30 is drilled horizontally through the oil field in proximity to and above horizontal oil/gas production well 21 . Horizontal radiofrequency well 31 is used to apply radiofrequency energy to the surrounding heavy crude oil field, thereby heating the oil and reducing its viscosity. Due to gravity, the reduced heated heavy crude oil drains, where it may be captured by and pumped out through oil/gas production well 20 to storage or processing equipment.
[0045] Radiofrequency energy is generated by a radiofrequency generator. It is transmitted via radiofrequency transmission line 40 through radiofrequency well 30 and horizontal radiofrequency well 31 to radiofrequency antenna 41 . Radiofrequency antenna 41 applies radiofrequency energy to the surrounding heavy crude oil, thereby heating it and reducing its viscosity so that it may be collected by and recovered through oil/gas production well 20 . The oil/gas production well 20 may also act as a parasitic antenna to redirect radiation in an upward direction toward the formation to be heated by the radiofrequency energy, thereby increasing efficiency.
[0046] For purposes of in situ processing and upgrading of the heavy crude oil, horizontal oil/gas production well 21 may be embedded in catalytic bed 50 . Horizontal radiofrequency well 31 may be strongly electromagnetically coupled to horizontal oil/gas producing well 21 so that the temperature of horizontal oil/gas producing well 21 may be precisely controlled, thereby allowing for upgrading of the heavy oil in horizontal oil/gas production well 21 over a wide range of temperatures. The upgrading can be based on several different known technologies, such as visbreaking, coking, aquathermolysis, or catalytic bed reactor technology.
[0047] Radiofrequency antennae may be placed in an oil field in numerous configurations to maximize oil recovery and efficiency. FIG. 2 shows a perspective view of an alternative arrangement of an in situ radiofrequency reactor. Radiofrequency antennae 41 may be placed in proximity to one another in oil field 10 . Radiofrequency energy is supplied to the antennae 41 by a radiofrequency generator and then applied to the oil field 10 . The resulting heating reduces the viscosity of the oil, which drains due to gravity. Horizontal oil/gas production well 21 is positioned below the antennae 41 to collect and recover the heated oil.
[0048] As with the RFR in FIG. 1 , this arrangement may also be used to process the heavy oil in situ. A horizontal radiofrequency well 31 with horizontal radiofrequency antenna 42 may be placed in proximity to horizontal oil/gas producing well 21 below antennae 41 to control the temperature of the oil. Horizontal oil/gas production well 21 may be embedded in catalytic bed reactor 50 . The oil may thereby be upgraded in situ.
[0049] FIG. 3 shows a top view of another arrangement for an in situ radiofrequency reactor for use in large oil fields. In this radial configuration, one central and vertical radiofrequency heating well 32 with radiofrequency antenna 41 is used for larger volumes of oil. Radiofrequency antenna 41 applies radiofrequency energy to area 11 , thereby heating the oil in that area. The heated oil drains to horizontal oil/gas production wells 21 for collection and recovery. Parallel horizontal radiofrequency wells 31 may also be used to heat the oil. In addition, radiofrequency antennae 43 may be placed in vertical radiofrequency wells 33 to assist with in situ upgrading of the heavy crude oil.
[0050] The radiofrequency antennae used in the RFR system of the present invention may be any of those known in the art. FIG. 4 shows a perspective view of a radiofrequency applicator that may be used with the RFR of the invention. Applicator system 45 is positioned within radiofrequency well 30 . Applicator system 45 is then used to apply electromagnetic energy to heavy crude oil in the vicinity of radiofrequency well 30 .
[0051] Applicator structure 46 is a transmission line retort. Radiofrequency energy is supplied to applicator 46 by an RF generator (not shown). The radiofrequency generator is connected to applicator 46 via radiofrequency transmission line 40 . The radiofrequency transmission line 40 may or may not be supported by ceramic beads, which are desirable at higher temperatures. By this means, the radiofrequency generator supplies radiofrequency energy to applicator 46 , which in turn applies radiofrequency energy to the target volume of oil.
[0052] Although one specific examples of an applicator structure is given, it is understood that other arrangements known in the art could be used as well. Uniform heating may be achieved using antenna array techniques, such as those disclosed in U.S. Pat. No. 5,065,819.
[0053] The present invention also has application in oil shale fields, such as those present in the Western United States. Large oil molecules that exist in such oil shale have been heated in a series of experiments to evaluate the dielectric frequency response with temperature. The response at low temperatures is always dictated by the connate water until this water is removed as a vapor. Following the water vapor state, the minerals control the degree of energy absorption until temperatures of about 300-350 degrees centigrade are reached. In this temperature range, the radiofrequency energy begins to be preferentially absorbed by the heavy oil. The onset of this selective absorption is rapid and requires power control to insure that excessive temperatures with attendant coking do not occur.
[0054] Because of the high temperature selective energy absorption capability of heavy oil, it is therefore possible to very carefully control the bulk temperature of crude oil heated by radiofrequency energy. The energy requirement is minimized once the connate water is removed by steaming. It takes much less energy to reach mild cracking temperatures with radiofrequency energy than any other thermal means.
[0055] Kasevich has published a molecular theory that relates to the specific heating of heavy of oil molecules. He found that by comparing cable insulating oils with kerogen (oil) from oil shale, a statistical distribution of relaxation times in the kerogen dielectric gave the best theoretical description of how radiofrequency energy is absorbed in oil through dielectric properties. With higher temperatures and lowering of potential energy barriers within the molecular complex a rapid rise in selective energy absorption occurs.
[0056] In use, a user of an embodiment of the present invention would drill oil/gas production wells and radiofrequency wells into a heavy crude oil field. At least a portion of the wells would be horizontal. The radiofrequency wells would be placed in proximity to and above the oil/gas production wells. The user would install a radiofrequency antenna in each radiofrequency well and supply such antennae with radiofrequency energy from a radiofrequency generator via a radiofrequency transmission cable. The user would then apply radiofrequency energy using the radiofrequency generator to the antenna, thereby applying the radiofrequency energy to the heavy crude oil in situ. The radiofrequency energy would be controlled to minimize coking and achieve the desired cracking and upgrading of the heavy crude oil. The resulting products would then be recovered via the oil/gas production well and transferred to a storage or processing facility.
[0057] Referring again to FIG. 4 , the applicator structure 46 is a vertical monopole antenna within a non-metallic production pipe (shown as a radiofrequency well 30 ). The production pipe extension below the applicator or antenna may be used to enhance the radiation efficiency by adjusting the length of the pipe. The pipe may extend into or below the subterranean oil or gas.
[0058] As described in the above background section, steam assisted gravity drainage (SAGD), is an existing commercial process for heavy oil recovery, used especially in high permeability reservoirs such as those encountered in the oil sands of Western Canada. Referring to FIG. 5 , in the SAGD process, two parallel horizontal oil wells 520 & 550 are drilled in the formation, one above the other (in some examples, roughly 10 meters apart). The upper well acts as a steam injector 520 and typically includes a slotted liner 522 (in some examples, roughly 300 meters long) for allowing steam to be released through the slots 530 . The steam increases the temperature of the crude oil in the oil sand formation 512 , reducing the crude oil's viscosity and allowing it to be collected by gravity drainage via the lower well, referred to as an oil producer 550 . The slotted liner 522 is typically made of conductive materials.
[0059] Referring to FIG. 6 , in some embodiments, the SAGD configuration is retrofitted to use one or both wells (or portions thereof, e.g., the liners) as an antenna for emitting RF energy into the oil sand formation. The RF energy increases the temperature of the crude oil, reducing its viscosity and allowing it to be collected. In some embodiments the oil is collected using a pipe (not shown) within the same well as the well 600 configured to host an antenna.
[0060] A coaxial cable 630 connects a power source (not shown), for example, a radiofrequency generator stationed on the surface, to the slotted liner 622 . The coaxial cable 630 has a central conductor 632 surrounded by a dielectric insulating portion and an outer conductive shield 634 . In some embodiments, the outer conductor 634 is also wrapped in an external insulating layer.
[0061] At the distal end of the well, the coaxial cable's central conductor 632 is electrically connected to the well's slotted liner 622 . In some embodiments, the connection to the liner 622 is achieved using a metal contact ring 660 to which the central conductor 632 is electrically connected 664 (e.g., welded). The contact ring 660 is mated with the liner 622 .
[0062] In some embodiments, an insulating section 650 is used, for example, to separate the slotted liner 622 from the well wall 620 . The insulating section 650 is a hollow cylinder that allows the coaxial cable 630 and any other cables or pipes (e.g., an oil collection pipe) to pass through it. In some examples, the insulating section 650 is ceramic.
[0063] As shown if FIG. 6 , the well 600 is supported in the earth 616 by a cement casing 614 . The cement 614 is susceptible to cracking if subjected to excessive heat. In such embodiments, it may be desirable to restrict the level of RF energy returning up the well 600 , for example, to reduce the risk of the cement 614 cracking. Therefore, a high impedance block is created.
[0064] In the embodiment shown in FIG. 6 , the outer conductor 634 of the coaxial cable 630 is electrically connected 648 to a quarter-wave choke assembly 640 . The optimal length of the choke assembly is an odd multiple of quarter-wavelengths (¼, ¾, 5/4, etc.). That is, the choke assembly 640 extends back from the insulator 650 at least one quarter of the maximum wavelength for the energy to be emitted from the antenna. The choke assembly 640 may extend further back, in some examples, extending all of the way back to the surface.
[0065] The quarter-wave choke assembly 640 includes an inner conductor 642 , which is separated from either the well wall 620 or an outer assembly casing 644 by either air or a dielectric layer 646 . The outer conductor 634 of the coaxial cable 630 is electrically connected 648 to the inner conductor 642 of the choke assembly 640 . The inner conductor 642 is shorted 654 to the inner side of the well wall 620 at the proximal end of the choke assembly 640 .
[0066] The quarter-wave choke assembly 640 creates a high impedance block restricting the flow of energy back up the well 600 . Alternatively, in some embodiments, the outer conductor 634 is electrically connected directly to the inside of the well wall 620 .
[0067] Referring again to FIG. 5 , in certain embodiments, multiple wells (e.g., both the steam injector 520 and the oil producer 550 ) are retrofitted as RF antennas. In such embodiments, the multiple antennas are powered in a manner to boost the RF energy, for example, by emitting energy in phase. In other embodiments, the phase of the energy emitted by each of the multiple antennas can be tuned to control the energy levels within the oil sand formation by controlling the antennas to emit out of phase.
[0068] In certain applications, the slots in the slotted liner are sized in a manner to increase the efficacy of subsequent RF retrofit. Referring to FIG. 7 , in some embodiments, a well 700 is configured with two slotted liners—an inner liner 710 and an outer liner 720 . Each liner includes slots 730 . At least one liner, e.g., the inner liner 710 , is configured to be adjusted, acting as a telescoping sleeve. By telescoping the liner, the size of the slots 730 are adjusted. The liner overlap 740 therefore creates variably sized slots. Using this approach, the slots in the slotted liner are dynamically sized as needed.
[0069] In some embodiments, the presence of the RF retrofit does not preclude the contemporary use of steam or other oil recovery methods. For example, the RF energy is used to initiate the process of oil recovery by alternative means.
[0070] Although the present invention has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
|
The present invention relates generally to a radiofrequency reactor for use in thermally recovering oil and related materials. The radiofrequency reactor includes a radiofrequency antenna configured to be positioned within a well, where the well is provided within an area in which crude oil exists in the ground. The radiofrequency antenna includes a cylindrically-shaped radiating element for radiating radiofrequency energy into the area in which crude oil exists. The cylindrically-shaped radiating element is configured to allow passage of fluids there through. The radiofrequency reactor also includes a radiofrequency generator electrically coupled to the radiofrequency antenna. The radiofrequency reactor is operable to control the radiofrequency energy generated.
| 4
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to machine controls and more particularly to the control of combustion in a burner for heating water or other substances by controlling air flow into the burner responsive to changes in physical parameters affecting air and or fuel density.
[0003] 2. Background and Description of the Prior Art
[0004] Burners for machine systems such as water heater boilers for example, generally mix a fuel in gas or liquid form with air to provide a source of heat. Efficient combustion occurs when (a) the ratio of the mass of air to the mass of fuel is held within a small range of values centered on approximately 18-to-1, and (b) sufficient air is mixed with the fuel to ensure combustion of all of the fuel plus some small amount of “excess air.” Generally, sufficient air is provided when the amount of excess air is approximately 15%, which corresponds with an air-fuel ratio of approximately 18-to-1. If the excess air exceeds about 15%, some of the heat produced is consumed heating the excess air and is thus not available for heating the water in the boiler. Thus, it is important to maintain a stable and relatively low excess air level.
[0005] However, unless the burner is operated in an atmosphere of substantially constant air temperature and barometric pressure, the setting of operating controls for the burner is at best only a rough approximation to an optimum level for efficient combustion over normal variations in temperature. Thus, these settings require a substantial offset to compensate for changes in the air temperature. The result is that excess air values often exceed the 15% figure by a wide margin, to as much as 30% or more, when the combustion air temperature changes, placing an extra burden upon the heat energy produced upon the burner. Such a situation may occur, for example, when the temperature may vary as much as 20° F. to 30° F. or more over a 24 hour period, or as much as 80° F. to 100° F. through seasonal variations. To compensate for such variations, some burner efficiency, and some fuel consumption, is traded off for ensuring complete combustion at all times to minimize unburned fuel and emissions.
[0006] Most burners built today use a “Volume Control” system to control the flow of fuel and air. On gas fueled burners, the fuel pressure is controlled with a regulating valve, and the correct flow rate is obtained with an orifice. The orifice may be fixed for “On-Off” firing or it may be a control valve (like a butterfly valve) which can be opened and closed to allow more or less fuel in. The combustion air is controlled in a similar manner, using a fixed orifice for “On-Off” air flow control and an air damper for modulating air control.
[0007] Conventional volume control systems for water heater burners are subject to errors in the control of the air and fuel rate because the correct proportions of air and fuel are defined by the mass flow not volume flow. For each pound of natural gas provided to the burner, a corresponding quantity of air is required (about 18 pounds of air). According to the gas laws, the mass provided by a given volume of air can vary according to its temperature and the barometric pressure. Thus, the ratio of mass to volume is defined as the density of a gas, and can be defined mathematically for our purposes as,
[0000] Actual Density=(Std. density)×(absolute pressure/std pressure)×(std temperature/absolute temperature), {Eqn. 1}
[0000] where:
[0008] Density=weight of gas per unit volume of gas (lb/ft 3 of gas at the stated pressure and temperature), and
[0009] Std. density=density of the gas at standard conditions (0.0765 lb/ft 3 for air at 60° F. and 29.92″ Hg), where:
[0010] Absolute pressure=gauge pressure+barometric pressure of the current condition;
[0011] Std pressure=standard pressure, 29.92″ Hg (barometric pressure);
[0012] Std temperature=standard temperature, 60° F.; and
[0013] Absolute temperature=460+the temperature in ° F. of the gas.
[0014] These changes in density can result in large changes in the air-fuel ratio and the excess air of the burner combustion. For example, a difference of a combustion air temperature change from 120° F. on a hot afternoon to 40° F. on a cool morning will result in an increase in excess air of about 14%. This means that the burner is passing through 14% more excess air at 40° F. than at 120° F., and heating this air from 40° F. to the stack temperature (which is often around 500° F.) requires proportionately more fuel. This significantly reduces the efficiency of the boiler-burner package, making it more expensive to operate.
[0015] Oil fueled systems are not subject to the same density variations as a gas fuel system, because the liquid oil has a very small change in properties with temperature and pressure. For oil firing, the temperature generally must be controlled to maintain good atomization. Moreover, the oil pressures are so much higher than atmospheric pressure that the change in atmospheric (i.e., barometric) pressure has little effect. The concept of density change can be applied to oil flow, but it offers a much smaller improvement.
[0016] The impact of temperature and pressure variation is seen in the limitations and alternate control methods and systems used by burner manufacturers. Following are listed some typical methods that burner manufacturers use to solve these problems.
a. The simplest means of handling this is to allow for higher rates of excess air in the burner, and especially on cold days, set up the burner with very high excess air rates so that when it gets hot, there is enough air available to completely burn the fuel. This may typically be described in the service manual as a basic setup requirement. b. Require the room to be heated to minimize combustion air temperature variations. c. Perform more frequent burner tune ups, especially on a seasonal basis, to correct for some of the variation in the combustion air temperature. d. Add an Oxygen Trim system to compensate for these changes by measuring the excess air and adjusting the fuel or air flow rate to obtain a constant excess air level. e. Applications with outdoor installation or ducted outside air are generally required to have this air heated to reduce the variation in temperature to minimize combustion stability problems. f. Add a fully metered control system. This system measures the mass flow of air and fuel. It is a very expensive option and rarely used.
[0023] The concept of a “Fully Metered System” or “Full Metered Cross Limited Control System,” as described in (f) above, is not new. These systems have been used in the industry for many years. However, such systems are very complex and expensive, and only used in a very small number of special applications where the added performance justifies the cost and complexity.
[0024] Therefore, substantial industry-wide savings could be realized if a simple, low cost system or method were available that offers the control and efficiency of a fully metered system without the complexity and cost, and which is simple, reliable, and can be installed without major modifications to the burner and/or the structure of the water heater or other heating system. Such a system would provide a practical and economical alternative means of improving the efficiency of countless water heating and other types of heating systems in use.
SUMMARY OF THE INVENTION
[0025] Accordingly, an advance in the state of the art is disclosed that applies corrections to the mass flow rate of combustion air into a forced-draft burner for a water heater or other heating system, and thus the air-fuel ratio, by directly measuring the combustion air temperature and/or the barometric pressure of the combustion air, and using these measurements to develop a fan speed drive signal that corrects the volume of air inlet to the burner without the use of the complex and expensive fully metered control systems, or elaborate feedback systems, or systems that require real-time combustion analysis, and the like.
[0026] In one embodiment, an apparatus for controlling air flow into a burner responsive to parameter variations affecting air density is disclosed comprising: a fan motor for driving an air inlet fan of the oil fueled burner; a barometric pressure sensor for providing a first indicator signal to a controller; a combustion air temperature sensor for providing a second indicator signal to the controller; and a controller for receiving the first and second indicator signals at respective first and second inputs and processing them according to a predetermined relationship to provide a fan speed drive signal from a controller output coupled to the fan motor. In one aspect of this embodiment the controller includes a PLC and a variable frequency drive system. In another embodiment, the controller includes a PLC and a variable DC voltage drive system.
[0027] In another embodiment, a method of combustion control in a burner is disclosed comprising the step of processing both a first signal corresponding to an absolute barometric pressure measurement and a second signal corresponding to a combustion air temperature measurement in a controller to generate a variable frequency fan speed drive signal for coupling to an AC motor, or a variable amplitude fan speed drive signal for coupling to a DC motor, for driving an air inlet fan of the burner. In one aspect of this embodiment, the method regulates the fan speed responsive to changes in the first and second signals to vary the air flow volume into the burner, such that the fan speed varies inversely with changes in absolute barometric pressure and directly with changes in the combustion air temperature.
[0028] In another embodiment an apparatus for controlling air flow into a burner responsive to parameter variations affecting air density is disclosed comprising: a fan motor for driving an air inlet fan of the burner; a barometric pressure sensor for providing an electrical signal proportional to air density in the vicinity of the burner to a controller; and a controller for receiving the electrical signal at a control input thereof and processing it according to a predetermined relationship to provide a fan speed drive signal from a controller output to the fan motor.
[0029] In yet another embodiment an apparatus for controlling air flow into a burner responsive to parameter variations affecting air density is disclosed comprising: a fan motor for driving an air inlet fan of the burner; a combustion air temperature sensor for providing an electrical signal inversely proportional to air density in the vicinity of the burner to a controller; and a controller for receiving the electrical signal at a control input thereof and processing it according to a predetermined relationship to provide a fan speed drive signal from a controller output to the fan motor.
[0030] In still another embodiment an apparatus for controlling air flow into a burner for heating water responsive to parameter variations affecting air and fuel density is disclosed comprising: a fan motor for driving an air inlet fan of the burner; one or more sensing devices selected from the group consisting of a barometric pressure sensor for providing a first indicator signal to a controller, a combustion air temperature sensor for providing a second indicator signal to the controller, a fuel temperature sensor for providing a third indicator signal to the controller, and a fuel pressure sensor for providing a fourth indicator signal to the controller; and a controller for receiving one or more of the first, second, third, and fourth indicator signals at respective inputs thereto and processing them according to a predetermined relationship to provide a fan speed drive signal from a controller output to the fan motor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 illustrates a pictorial and block diagram of one embodiment of a water heater burner according to the present invention; and
[0032] FIG. 2 illustrates a block diagram of a control portion of the one embodiment of the water heater burner of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0033] The embodiment of the present invention described herein is not intended to be limiting but to illustrate the principles and the application of the invention. The present embodiment applies corrections for both combustion air temperature and barometric pressure to an illustrative water heater burner system. As used in the following description, combustion air is the air inlet to the burner, whether it is the ambient air at the inlet to the burner, indoor air ducted to the burner air inlet, or outside air ducted to the burner air inlet. However, the invention may be adapted to use the correction systems individually for temperature or pressure or to either gas-fueled or oil-fueled burners, depending upon the particular application. Further, while the embodiment to be described focuses on the particular control mechanisms that may be embodied in an illustrative water heater system, the present invention is readily adaptable to burners used in other applications such as steam boilers, kilns, foundries, etc. Moreover, because the present invention provides a control mechanism that operates independently of the usual mechanisms found in the illustrative water heating systems that utilize burners, many of the structural and operating details of these usual mechanisms of the water heaters, well known to persons skilled in the art but unrelated to the present invention, are not described herein.
[0034] Regulating the operation of a burner involves the application of several well-known relationships for gases. The density of a gas D is determined by the amount of the gas per unit volume, or, mass/vol or, D=m/V. The Ideal Gas Law states that the volume of a gas is related to the temperature and pressure by the formula P×V=k×T, where P=pressure; V=volume, T=temperature, and k=constant. Restated, this relationship is V=(k×T)÷P, or, simply V ∝T/P. Thus simplified, the density D∝m÷(T/P), or, D∝m(P/T). In words, density is proportional to pressure and inversely proportional to temperature. In a burner, to maintain an efficient combustion ratio, the parameter of interest is the mass flow rate of the air or the gas into the burner. Since the mass of a gas varies with its density, the mass flow rate of the gas (or air) varies with barometric pressure and inversely with ambient temperature.
[0035] The present invention described herein takes advantage of the dependence of the density of air used in a combustion mixture with a gas or oil (liquid) fuel upon the combustion air temperature and barometric (atmospheric) pressure of the air inlet to a burner for an illustrative water heater. This relationship, since it defines the effect of combustion air temperature and barometric pressure upon the mass of air and thereby the mass flow of air inlet to the burner, enables control of the air-fuel ratio, the ratio of the masses of the air and fuel, based on the outputs of combustion air temperature and barometric pressure sensors placed in the inlet side of the burner system. To say it another way, the system applies corrections to the air flow in response to variations in those attributes that would alter the mass flow rate and upset the air-fuel ratio of the mixture into the burner. The control provides correction of the air-fuel ratio for the changes in combustion air temperature and pressure that may occur during normal operation of the burner, whether the variations take place daily or seasonally. Not only is the air-fuel ratio held within more efficient limits, but the excess air is also controlled more closely to the preferred range of air-fuel ratios, providing a burner system that will have fewer maintenance problems caused by flame instability when operating at very high air-fuel ratios. The result is more reliability and a savings of fuel and energy costs provided by a more efficient burner. Moreover, because the control reduces the fan speed, it will also provide a savings of electrical energy, an inherent benefit of using a variable frequency drive (“VFD”) for use with AC fan motors, or a variable speed drive (“VSD”) for use with DC fan motors, that is described herein.
[0036] One important operating parameter of burners that is related to the air-fuel ratio for efficient combustion and to the stability of the combustion that occurs in the burner is called “excess air.” The optimum air-fuel ratio of the masses of air and fuel flowing into the burner for efficient combustion is approximately 16 pounds of air for every pound of fuel consumed, i.e., 16 to 1. If less air is inlet to the burner for each pound of fuel, the result is lower heat output and the emission of unburned fuel, representing wasteful operation. If more than 16 pounds of air is inlet to the burner for each pound of fuel, some of the energy in the fuel is used to heat the excess air and the combustion is operating too lean, representing inefficient operation. It turns out that some small amount of excess air—e.g., 10% to 15%—is preferred to ensure complete burning of the fuel, resulting in an air-fuel ratio of approximately 18 pounds of air to one pound of fuel. Thus, a measure of the combustion efficiency is the amount of excess air that is permitted. Normally, a range of percentages, from about 10% to 30% is allowed, which accommodates a range of operating conditions such as air temperature and other parameters that affect the density of the air inlet for combustion, and ultimately, the air to fuel ratio.
[0037] One condition that can occur if the excess air becomes too large a percentage of the optimum mass flow rate of the air is called “flame instability.” This occurs when there is insufficient fuel involved in the combustion process, i.e., an overly lean mixture of fuel in proportion to the available air. The resulting flame is starved for fuel, making it uneven and unstable. An unstable flame may cause the burner to “huff and puff,” as it tries to adjust to the excessive amount of air, with very poor efficiency and low or intermittent heat output. In severe cases, the burner may shake with the uneven burning, possibly leading to vibration and damage to burner structure, etc.
[0038] The present invention, by fine tuning the air to fuel ratio in response to factors that affect the density of the air and, to a lesser extent, the fuel in some applications, acts to prevent instability and to maintain the excess air within a smaller range that is closer to the optimum value over a wider range of temperatures and pressures. Thus, maintaining the excess air within a narrower range results in direct energy savings and improved efficiency. The present invention, as will be apparent from the following description, is also simple, easy to adapt to existing systems, and is relatively low in cost. It also results in a smoother operating burner system and improved longevity.
[0039] The system and method of the present invention may be retrofitted to existing burners without modification to the burner components. Since the system and method involves control—i.e., electrical changes—only of the inlet air fan, it is independent of the burner hardware and thus does not involve or affect the burner itself, which operates according to its own control loop. Moreover, it is low in cost, requiring only the addition of a temperature and/or a barometric pressure sensing devices, an interface circuit or system such as a VFD system or a VSD system (also called VFDS or VSDS, respectively herein), all of which are nominal cost items, to implement the system.
[0040] The interface circuit or system receives the signals from the sensing devices and processes them according to a well-defined transfer function, producing a fan speed drive signal that varies the speed of the AC motor driving the inlet air, aka the “combustion air” fan. The fan speed drive signal may be a variable amplitude DC voltage or a variable frequency AC voltage, depending upon the type of motor used in the system. The present invention quantifies, as a percentage of flow, the change in air density caused by the changes in combustion air temperature and barometric pressure, as defined by the Ideal Gas Law. The Fan Laws state that, at a constant fan speed, the air volume provided for the combustion of the fuel will remain the same even though the density has changed, resulting in a mass flow change directly related to the density change caused by changes in combustion air temperature and barometric pressure. Further, the Fan Laws state that a change in fan speed will result in a proportional volume change. Thus, changing the fan speed the same percentage as the resulting density changes will correct the density change and provide a constant mass flow of air for combustion. For example, if the density relations indicate that the mass flow rate is reduced 3% because of an increase in temperature, the system can increase the fan speed by 3% to correct for the change in density caused by the change in temperature.
[0041] In practice, persons skilled in the art will recognize that, while the Ideal Gas Law and the Fan Laws provide the foundation of the control strategy embodied in the present invention, some minor variations in the actual flow characteristics may be noticed in real world applications. In such cases, engineering design and experimentation are relied upon to make needed adjustments or to compensate for these variations from the ideal case. The control described herein, because it is configured to affect only the fan speed, is readily adaptable to existing systems largely without affecting the control mechanisms already in place. Such mechanisms include linkage or parallel positioning systems that control the operation of valves through mechanical linkages, from those that provide a simple ON-OFF, LOW-HIGH-LOW control to those operated by multiple linkages connected to a single actuator or to those providing continuously variable control operated by a modulation motor. Actuators and modulators may be controlled by switches or electronics.
[0042] Referring to FIG. 1 , a pictorial and block diagram illustrates one embodiment of a water heater system 10 according to the present invention. The water heater system 10 includes a boiler 12 and a burner system 14 controlled by a controller (or control section) 16 . The illustrated boiler 12 includes a feed water inlet 20 and a heated water or steam outlet 22 and a flue gas outlet 24 . A water temperature sensor 26 may be provided via a signal line 72 to a control panel 68 in the controller 16 . The water in the boiler 12 is heated by a firing head 30 where combustion air and fuel are mixed and ignited. The fuel is introduced into the firing head 30 via a pipe 32 . The inlet combustion air 34 is inducted via a fan 36 enclosed within the housing of the burner 14 . The fan in this example is driven by a three phase, 60 Hz AC motor 38 in the illustrative water heater system 10 . In similar applications, the fan motor 38 may be a DC motor. The burner system 14 includes a plenum portion having an inlet 40 controlling the air volume via a damper valve 42 . The damper 42 is operated by a lever and linkage 84 connected to a modulator motor 80 . The burner system 14 also includes a fuel feed system that receives fuel from a fuel supply via a pipe 90 feeding through a fuel pressure regulating valve 92 , a control valve section 94 , a fuel metering valve 88 , and ultimately into the pipe 32 and the firing head 30 . The control valve section 94 may include solenoid or motor-operated safety shut-off valves 96 and/or manual valves 98 as shown. The fuel metering valve 88 may be controlled by a lever and linkage 86 connected to the modulator motor 80 . The modulator motor 80 and the valves operated by motors or solenoids 96 may receive operating control signals via lines connected to the control panel 68 .
[0043] Continuing with FIG. 1 , the control section 16 of the water heater system 10 will be described. The three phase, 60 Hz AC motor 38 that drives the fan 36 receives its three phase operating voltage via the lines 44 connected to a VFD 64 . The VFD 64 is a variable frequency drive (VFD) that provides at its output a variable frequency, three phase AC voltage for powering the motor 38 . Motor 38 may be a three phase AC motor that, when supplied its normal rated 60 Hz input, operates at its rated speed of 3500 revolutions per minute (rpm), driving the fan 36 to deliver an air volume regulated by the air damper 42 in cubic feet per minute into the burner system 14 . Through the VFD 64 , the speed of the fan 36 may be varied or, in this embodiment, slowed down from 3500 rpm by reducing the frequency of the AC voltage supplied to the motor 38 from the rated 60 Hz to some lower value. The VFD 64 in the illustrated embodiment is powered by a three phase, 60 Hz AC supply voltage via the lines indicated by the reference number 72 . In alternate embodiments contemplated within the scope of the present invention, fan motors may be configured for operation on single phase AC voltage or at other nominal speeds at their rated 60 Hz inputs, such as 1750 RPM, 1120 RPM, etc. In alternate embodiments contemplated within the scope of the present invention that employ DC motors, the speed of the DC motor may be varied using a variable speed drive (“VSD”) unit that varies the amplitude of the voltage to the DC operated motor. In such applications, the VSD unit would be responsive to the same control inputs from combustion air temperature sensors, barometric pressure sensors, or a programmable circuit system, as described for the system using AC motors described in detail herein.
[0044] Returning to the illustrated embodiment, the VFD is also coupled to the control panel 68 via the line 70 to enable it to be responsive to other control parameters and conditions. Line 70 is typically a cable containing numerous connections to the control panel 68 . The control panel 68 controls the operations of the VFD 64 in response to a variety of conditions to provide efficient operation, save energy, and maximize the safety and reliability of the burner. The AC motor 38 may be closely controlled in start/stop, speed control, ramping up/down of the fan 36 . Operating limits are also closely controlled to avoid damage or unsafe conditions. While important to the operation of the water heater and burner system, these functions of the control panel 68 are not relevant to the present invention and will not be described further herein. Thus the present invention may be implemented or retrofitted to existing equipment at nominal cost and without requiring modifications to the system other than adding several nominal cost components and changing some of the wiring.
[0045] Two sensors are provided in the controller 16 for the burner system 14 shown in FIG. 1 . A barometric pressure sensor 50 , including a probe 52 , is installed near the burner system 14 to measure the atmospheric pressure. In addition, a combustion air temperature sensor 54 , including a probe 56 , is installed in a position near the damper 42 to measure the combustion air temperature. Both sensors 50 , 54 provide direct current (DC) electrical outputs to be used as indicator signals corresponding to the measured values of the sensors. These outputs vary between 4 milliAmperes (mA) and 20 mA, according to industry standard practice. In the illustrated embodiment, a suitable pressure sensor is provided by a type GP311 industrial grade pressure transducer manufactured by GP:50 NY Ltd., Grand Island, N.Y. 14072, and www.GP50.com. This transducer includes the sensor and a transmitter for sending the 4-to-20 mA output signal current to the input of the PLC 58 . A suitable temperature sensor is a resistance temperature device (RTD) provided by a type T91U-2-D rangeable transmitter and duct sensor manufactured by Kele Inc., Bartlett, Tenn. 38133, and www.kele.com.
[0046] The pressure and temperature sensor outputs are coupled respectively via lines 60 and 62 to a circuit or circuit system such as a PLC 58 , to be processed and converted to a fan speed signal under program control. Persons skilled in the art will realize that a specially-designed circuit could be used for the circuit system at block 58 . However, a programmable logic controller (PLC) is convenient because it is an off-the-shelf component that can receive multiple inputs and can be programmed for multiple outputs. Further, through its ability to respond to programmed instructions, it can apply an appropriate transfer function to the processing of the input indicator signals to produce the fan speed signal at the output of the PLC via the line 66 coupled to the VFD 64 . In the illustrative example, a suitable PLC device is a Part No. HE-XE105 manufactured by Horner APG, LLC, Indianapolis, Ind. 46201, and www.heapg.com. The output of the PLC 58 may be coupled to an input of a VFD 64 . The VFD 64 is a machine control to be described that is present in the AC supply circuit to the fan motor 38 . In the present invention, the VFD 64 is utilized to also respond to the fan sped signal as a control input from the PLC 58 by varying the frequency of the AC voltage to change the speed of the fan motor 38 . In other embodiments having only a single control input, such as either temperature or barometric pressure, that control input (sensor output) can be connected directly to the VFD 64 as long as the signal complies with the standard 4 mA to 20 mA range.
[0047] The VFD 64 is a standard off-the-shelf component that provides a control method for correcting the air-fuel combustion ratio for changes in the ambient temperature and barometric pressure. As noted herein above, the flow rate of the air 34 inlet to the firing head 30 is a direct, linear function of the speed of the fan 36 because of the fan law. The VFD 64 in this example z operates from a three phase AC voltage supply via the lines 72 and includes a rectifier, a frequency inverter, and a control section as internal circuitry (not shown) to regulate the frequency of the output waveforms in accordance with the fan speed signal from the PLC 58 . The fan speed signal input to the VFD 64 from the PLC 58 may be a DC current, such as a 4 mA to 20 mA current, or it may be a DC voltage varying in the range of 0 to 10 Volts DC, for example, according to industry standard practice.
[0048] The VFD 64 generates a variable frequency AC voltage to drive the AC operated fan motor 38 . The fan motor 38 , which nominally operates at 3500 RPM (in this example) when the AC supply voltage is 60 Hz, may be slowed down by reducing the frequency of the AC voltage generated by the VFD 64 . This variation in the AC voltage output frequency is proportional to the fan speed drive signal supplied by the PLC 58 and coupled to an input of the VFD via the line 66 . The VFD is a device known in the industry as a general machinery drive. In the illustrated embodiment, the VFD may be a type ACS350 manufactured by ABB Inc., New Berlin, Wis. 53151, and www.abb.us/drives.
[0049] In an alternative embodiment that is not illustrated herein but will readily occur to persons skilled in the art, the VFD 64 may be replaced by a variable speed drive (“VSD”) that provides a direct current fan speed drive voltage for controlling a DC operated fan motor. Substitution of a DC motor for an AC motor does not change the present invention, is contemplated as falling within the scope of the present invention, and is merely a functionally equivalent choice made to satisfy a particular application. Some burners for heating water, or used in other systems may utilize a DC motor as efficiently as an AC motor. In such applications, a variable speed drive or VSD is substituted for the VFD. A VSD may be configured to be responsive to a DC fan speed signal output to the VSD by the PLC.
[0050] While the present invention is illustrated herein by an embodiment having control of both the combustion air temperature and the barometric pressure, other applications may use differing embodiments, considering factors such as the following. For example, in gas burners, both the air and gas supply pressures are referenced to the barometric pressure. The inlet pressure to the fan is the atmospheric pressure, and the gas pressure regulator controls to some pressure over the atmospheric pressure. Thus, in the case of a gas burner, these two pressure effects change in the same direction, and in most cases a correction to the mass flow of the air inlet is required only for variations in the ambient temperature. However, in gas burners with a vented gas pressure regulator, a slightly modified correlation may be required because the barometric pressure change will also change the gas pressure. The correction adjustment may be made in the PLC 58 by referencing the regulated gas pressure. In the case of an oil burner, since the variations in atmospheric pressure will affect the air mass flow while the oil mass flow rate remains unchanged, a correction to the mass flow of the air inlet is required for variations in both the combustion air temperature and the atmospheric (i.e., barometric) pressure.
[0051] Referring to FIG. 2 , there is illustrated a block diagram of the control portion of the embodiment of the water heater burner illustrated in FIG. 1 . In FIG. 2 the same reference numbers are used to identify the same structures. A pressure sensor 50 and its probe 52 are shown connected through the line 60 to the PLC 58 at terminal “L” and to a power supply 100 at a terminal marked V+, and through the other side of the line 60 to a terminal labeled MA2 of the PLC 58 . Similarly, a temperature sensor 54 and its probe 56 are shown connected through the line 62 to the PLC 58 at terminal “L” and to the power supply 100 at the V+terminal, and through the other side of the line 62 to a terminal labeled MA1. The PLC 58 is powered by the power supply 100 along connections from V+ and V− respectively to terminals labeled L and N. The fan speed signal output from the PLC 58 is coupled to the VFD 64 along the two wire line 66 between the PLC 58 at terminals labeled AQ1 and DV to the VFD at control terminals 5 (+) and 6 (−).
[0052] The VFD 64 is a machine control unit connected between the three phase AC supply source and the AC supply terminals of the fan motor 38 . Thus, the L 1 line in cable 72 connects to terminal U 1 of the VFD 64 and terminal U 2 of the VFD 64 connects to an L 1 terminal of the fan motor 38 . Similarly, line L 2 from the source connects via cable 72 through terminals V 1 , V 2 to an L 2 terminal of the fan motor 38 and an L 3 line in cable 72 connects through terminals W 1 , W 2 to an L 3 terminal of the fan motor 38 . A ground connection from terminal PE of the VFD 64 is provided on the AC source side and a ground connection from the terminal PE on the output of the VFD 64 is provided to the frame of the fan motor 38 . The cable 44 from the VFD 64 may be shielded, with the shield connected to the PE terminal of the VFD 64 . The control panel 68 shown in FIG. 2 includes substantial circuitry for regulating various safety and operating functions of the water heater burner, including the fuel supply, water temperature, etc. Since the present invention provides control of the inlet air by regulating the inlet fan speed independently of the rest of the burner system, the control panel operation is not relevant to describing the operation of the present invention. The control panel is shown connected to a source 102 of 120 VAC/60 Hz power that is coupled to the control panel 68 via a line L ( 104 ) and a line N ( 108 ). The line L ( 104 ) includes a 5 Amp fuse 106 .
[0053] The linear speed control characteristic provided by the VFD 64 enables a simple relationship between the variations in the sensed parameters and the speed of the fan motor 38 to be established by the control section 16 . For example, in a typical application where the air temperature is expected to vary between 50° F. and 120° F., the maximum motor speed, 3500 rpm at 60 Hz, may be set to correspond to the maximum temperature, 120° F. (where the air has the lowest density) and the minimum motor speed may be set to, for example, 3077 rpm at the 50° F. temperature of the ambient air where the air has the highest density. The speed of the fan motor 38 is held constant above 120° F. and below 50° F., and varies linearly between these two temperatures. These limits are typically determined by factory settings. The factory settings cover all the expected temperatures of operation, the fuel input rate and the amount of air required to completely and efficiently burn all of the fuel, and standard temperature and barometric pressure for the region where the system will be operating. An example of the calculation to determine the speed of the fan motor 38 at 50° F. follows.
[0054] Consider the application where the air temperature varies from 120° F. (condition 1) to 50° F. (condition 2), and the normal barometric pressure is 28.7″ Hg. We will use several standard values and relations in the following calculations. They are:
[0055] Density=weight of gas per volume of gas (lb/ft 3 of gas at the stated pressure and temperature);
[0056] Std. density=density of the gas at standard conditions (0.0765 lb/ft 3 for air at 60° F. and 29.92″ Hg);
[0057] Absolute pressure=gauge pressure+barometric pressure of the current condition;
[0058] Std pressure=standard pressure, 29.92″ Hg (barometric pressure);
[0059] Std temperature=standard temperature, 60° F.; and
[0060] Absolute temperature=460+° F. of the gas.
[0061] Based on the known fuel input, the burner requires 10,000 pounds per hour of air to completely and efficiently burner all of the fuel provided by the burner. The following analysis would be used to generate the control strategy.
[0062] The densities of the air at the two conditions are (from Eqn. 1);
[0000] Density 1=0.0765×(28.7/29.92)×(460+60)/(460+120)=0.06579 lb/cuft
[0000] Density 2=0.0765×(28.7/29.92)×(460+60)/(460+50)=0.07482 lb/cuft
[0063] The required fan output for each condition will be, using
[0000] Fan Actual Cubic Feet per Minute (ACFM)=(lb air/hr)/(density×60 min/hr) {Eqn. 2)
[0000] ACFM1=10,000/(0.06579×60)=2533 CFM
[0000] ACFM2=10,000/(0.07482×60)=2228 CFM
[0064] Where the values are;
[0065] Lb air/hr=pounds of air required per hour (as stated in this example);
[0066] Standard air density=0.0765 lb/ft 3 ;
[0067] Standard air pressure=29.92″ Hg;
[0068] Local air pressure=28.7″ Hg;
[0069] Air temperature at condition 1=120° F.;
[0070] Air temperature at condition 2=50° F.; and
[0071] RPM=revolutions per minute.
[0072] The burner was setup under condition #1 at 120° F., which is the lowest air density. The combustion air motor and fan are operating at 3500 RPM and the air damper is adjusted to generate a flow of 2533 CFM, which provided enough air to completely burn the fuel and some minimal amount of excess air, for good combustion efficiency.
[0073] At condition #2, the fan will generate the same volume of air (based on fan laws), and since the density is much higher (more pounds of air per volume at this lower air temperature) the burner would normally have much more air then needed for combustion. A higher excess air rate would result in lower combustion efficiency. The system of the present invention will change the fan speed to match the changes in air temperature, and provide the same mass of air to the burner firing head 30 . The new fan speed required to obtain a volume flow of 2228 CFM is,
[0000]
R
P
M
2
=
(
R
P
M
1
)
×
(
A
C
F
M
2
/
A
C
F
M
1
)
=
(
3500
R
P
M
)
×
(
228
/
2533
)
=
3077
R
P
M
{
Eqn
.
3
}
[0074] Where,
RPM1=RPM at condition 1, and RPM2=RPM at condition 2.
[0076] The foregoing example illustrates an application of the present invention to a water heater burner system wherein the combustion air temperature alone is used as a control parameter to vary the speed of the fan motor 38 . This example is simple and low cost, making it especially adaptable to smaller burners with lower fuel costs and lower payback opportunity. In this application, the PLC is not needed because the 4 to 20 mA analog control input to the VFD 64 is available. The VFD device generally has this capability through its built-in single loop controller to convert the DC control input to the fan speed control signal. This particular embodiment thus does not require any programming and would be transparent to the start-up technician and in use. Persons skilled in the art will readily be able to adapt the invention to their specific system based on the description provided in the foregoing example.
[0077] Other applications of the present invention include a simple pressure control package for burners that again utilizes the single loop controller of the VFD 64 and a barometric sensor such as the sensor 50 and probe 52 combination described herein above. The process for configuring the system is similar, based on initial conditions defined for two different air densities and the corresponding fan outputs (ACFM 1 and ACFM 2 ) calculated from: (amount of air required, in lb., for the given amount of fuel)÷(air density, in lb./cu. ft.) for each of the two conditions. For a hypothetical atmospheric pressure range of 27.7 in. (condition 1) to 29.7 in. (condition 2), a temperature of 85° F. and 10,000 lb. of air required to burn the fuel, ACFM 1 =2466 CFM and ACFM 2 =2300 CFM. At condition 1, the RPM, is set to 3500 RPM for apressure of 29.7 in. Then RPM 2 is determined by: RPM 2 =3500 (2300÷2466)=3264 RPM. Notice in this example that the highest fan speed is set to the lower pressure boundary, where the density of the air is lower. As the pressure rises, the density of the air increases, and the fan speed necessary to maintain the correct CFM must be reduced.
[0078] In another application of the present invention for water heaters, both combustion air temperature and barometric pressure corrections can be implemented. The system is much like the illustrated embodiment described herein above. From the previous examples of single control elements, the correction for air temperature and pressure has been defined. They can be combined in the following manner, wherein the calculations are performed in the PLC responsive to inputs from both types of sensors. Correction factors for the ambient air temperature and the barometric pressure are defined as follows:
[0000] K T =(460 +T air)/(460 +T max); and
[0000] K P =Bp low/ BP air.
[0079] Thus, the fan speed is determined by:
[0000] Speed=3500 RPM× K T ×K P ,
Where,
[0080] K T =Temperature correction factor (dimensionless);
K P =Barometric pressure correction factor (dimensionless);
BP air =current barometric pressure, Hg, in.;
BP low =lowest barometric pressure, Hg, in.;
Tair=current air temperature, ° F.;
Tairmax=the highest expected combustion air temperature ° F.; and
Speed=controlled RPM of the combustion air fan motor.
[0081] These calculations provide a set of relationships—which may be represented by a family of characteristic curves, if plotted (i.e., one curve for each increment of barometric pressure, when the axes are motor speed vs. combustion air)—where the different barometric pressures would be identified with multiple lines. These operations would be performed on a continuous manner, where the fan speed drive signal is always calculated and delivered to the VFD, and the fan always operates at the correct speed for the operating conditions. When the unit is initially setup, it will be calibrated to the correct mass flow, as measured by a combustion analysis performed at startup.
[0082] The foregoing are just a few of the examples of combustion control through applying measurements of temperature and pressure of the ingredients of the combustion process. Other potential applications include controls based on: gas fuel temperature; combined fuel temperature, combustion air temperature and barometric pressure; and outside ducted combustion air temperature. Any combination of combustion air temperatures, barometric pressure, gas fuel temperature and gas fuel pressure can be used by applying the Ideal Gas Law and the Fan Laws.
[0083] The present invention may even be used to correct the fan speed in a burner system that already uses a variable speed control to maintain a constant pressure at the air inlet of the burner, between the air damper and the fan. In such a variable motor speed control system, a pressure sensor is located between the air damper and fan inlet to measure the pressure at that location. A single loop controller reads this pressure and is programmed to maintain a constant pressure, typically around −2.0″ w.c. (inches of water columr). Note, for reference, 27.7″ w.c. in a tube=1.0 pounds per square inch (“psi”). As the air damper opens, the pressure drops, and the control will increase the fan motor speed to maintain the set pressure. As the air damper opens, increasing the air supply to the burner, the firing rate is allowed to increase. If the air damper is located on the outlet side of the fan, the pressure will be positive instead of negative. This system has been used in many applications over the years. Typically, the motor will vary from about 1000 RPM at low fire up to 3500 RPM at high fire. The electrical use at the lower firing rates is considerably lower than the standard burner, and results in a significant electrical savings. Rebates from electric companies may be available for these applications.
[0084] In some applications, known as so-called “true variable speed systems,” where the fan speed is controlled over a large speed range, e.g., 1000 RPM to 3500 RPM, control based on temperature offers true savings. This is also true for combined sensing, such as temperature and pressure, yielding improved efficiency and savings. The present invention is primarily directed to and contemplated for use with systems in which substantial gains in efficiency can be realized by varying the fan motor speed over a narrower range, such as 2800 to 3500 RPM. Nevertheless, the principles of the present invention may readily be applied to control of the wider range of speeds, with corresponding improvements in efficiency and reduced operating costs.
[0085] To combine the electrical savings of the standard variable speed motor control with, for example, the air temperature control of the illustrated embodiment described herein above, the application of the air temperature adjustment would be accomplished using a “square law” that says the ratio of pressures equals the ratio of the flows squared, or
[0000] P 2 =P 1 ×(ACFM 2 ÷ACFM 1 ) 2 {Eqn. 5}
[0086] Where,
[0087] P 2 =New pressure set point between the air damper and fan;
[0088] P 1 =Original pressure set point between the air damper and fan, −2.0″ wc;
[0089] ACFM 1 =air flow rate before temperature change; and
[0090] ACFM 2 =air flow rate required after temperature changes.
[0091] The ratio of old to new air flow is represents the volume air flow rate change required to maintain the same mass flow rate of the burner, which can be determined directly from the temperature change as done in the described embodiment, with the final form of:
[0000] P 2 =P 1 ×(460 +T air)/(460 +T airmax) {Eqn. 6}
[0092] Where,
[0093] Tair=current air temperature, ° F.;
[0094] Tairmax=the highest expected combustion air temperature ° F.;
[0095] Maximum air temperature=maximum expected air temperature ° F.; and
[0096] Absolute temperature of air=(460+air temperature ° F.).
[0097] A PLC is required to combine the readings of the pressure sensor and offset according the above (equation 6). This would be converted to a 4-20 mA signal that can be used by the single loop controller in the VFD, which will vary the combustion air motor speed to maintain the desired set point pressure.
[0098] While the invention is described in only several of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit thereof. In the illustrative example, the control system is an electrical or electronic device, which is a typical implementation of machine control systems. In some electrically-based systems, substitutions may be made. For example, the PLC and/or the VFD or VSD may be replaced by a circuit specifically designed to process the sensor outputs and generate the particular kind of control or “fan speed signal.” Further, other systems may be more amenable to control systems based on hydraulic or pneumatic circuits for sensing operating parameters and generating corresponding outputs to maintain the mass flow rate of air inlet to a burner within an optimum range for high efficiency. In other systems, the control outputs may be derived from sensors that detect variations in fuel parameters and adjust the inlet air flow to maintain a predetermined combustion efficiency and performance.
|
A method and apparatus that applies corrections to the mass flow rate of combustion air into a gas or oil-fired, forced-draft burner, and thus provides for correcting the air-fuel ratio, by directly measuring the combustion air temperature and/or the barometric pressure of the combustion air, and using these measurements to develop a fan speed drive signal that corrects the volume of air inlet to the burner system without the use of the complex and expensive fully metered control systems, or elaborate feedback systems, or systems that require real-time combustion analysis, and the like.
| 5
|
This disclosure is based upon, and claims priority from, French Patent Application No. 98/01370, filed Jan. 22, 1998, and International Application No. PCT/FR99/00052, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a standardized integrated circuit contact card, also usually referred to as a smart card.
The invention more particularly relates to a standardized smart card which can be transformed irreversibly into a standardized mini smart card.
The invention thus relates to a standardized integrated-circuit contact card of the type having a support in the form of a rectangular plate delimited by two long longitudinal edges and two short transverse edges, front and rear, which carries at least one electronic microcircuit and whose reverse face has a series of contact areas, arranged close to the front transverse edge of the card, for the electrical connection of the microcircuit to an operating circuit belonging to a device having for example a connector in which the card is fitted so that its contact areas cooperate with contact blades on the connector, and of the type having a slot with a substantially rectangular contour formed in the support, around a portion including the microcircuit and the series of contact areas, in order to delimit a detachable standardized minicard which is connected to the card support by several lugs, produced in one piece with the support, which extend between the internal edges of the cutout formed by the slot in the card and the facing edges of the minicard which are roughly parallel to the edges of the card.
According to such a known design, which is for example illustrated in the document EP-Bl-0.521.778, it is possible to simply transform the card, or a large card known as an SIM card, whose format is in accordance with the international standards GSM 11.11 and ISO 7816, into a standardized mini SIM card, whose dimensions are also defined by the international standard GSM 11.11, by detaching the latter from the card by breaking the lugs or connecting bridges, this rupture being able to be effected notably manually by pressing the minicard overall in a vertical direction perpendicular to the overall plane of the card.
This known design makes it possible to supply the card “complete” to a user, that is to say of course without detaching the minicard, to enable him to use the chip with a card in one or other of the two formats (card or minicard) according to the receiving apparatus in which he has to insert the card.
The product manufactured and supplied to the users must, in addition to the standards mentioned above defining the design and geometry of the two types of card, comply with other parameters and requirements.
Each of the two cards must in particular be able to meet, in accordance with the ISO standard, mechanical strength tests including notably repeated bending/torsion cycles, without there being any visual or functional degradation of the chip, the module incorporating the chip and inserted in the card support, or the plastic body of the card forming the support proper.
These mechanical constraints must in particular be withstood by the large card, as well as of course by the minicard.
For practical reasons, it is desirable for the minicard to be able to be detached easily from the body of the large card by a manual operation, without using any specific tool and without impairing the functioning and subsequent reliability of the minicard thus obtained.
It is desirable to improve the structure of the card in order in particular to facilitate still further the manual separation, whilst guaranteeing resistance to bending/torsion in accordance with the ISO standard.
Provision is for example made for the use of more fragile chips or modules in the future and, in this case, it is preferable not to have any risks, even insignificant, of damaging the chip or module.
In addition, one or the other of the two cards must be able to be used without presenting problems of insertion or extraction of the card into or from its receiving device, and particularly in the connector, more particularly when a card is introduced into the connector in a direction substantially parallel to its overall plane with its transverse insertion edge corresponding, in the case of the large card, to its front transverse edge adjacent to the contact areas for connection of the chip and, in the case of the minicard, to one or other of its two parallel opposite transverse edges.
It is also desirable, in particular when the large-format card is used, for the cutout slot, and/or complementary grooves constituting incipient breaks in the connecting lugs, not to damage the elastic contact blades of the connector because of its repeated passage opposite the free contact ends of the contact blades of the connector during repeated operations of inserting and extracting the card.
SUMMARY OF THE INVENTION
In order to remedy the drawbacks which have just been mentioned and to satisfy the different requirements for reliability of the cards and connectors, the invention proposes a card of the type mentioned above, characterized in that each lug has two types of groove opposite each other, shaped so as to be sufficiently resistant to bending/torsion forces in accordance with a standard, one of the grooves however also being shaped so as to more easily initiate a crack by intentional manual pressure on the minicard.
According to other characteristics of the invention:
the card has three connecting lugs including a first lug extending longitudinally from the front transverse edge of the minicard adjacent to the front transverse edge of the card, whose width is at least equal to the width of the series of contact areas arranged close to the front transverse edge of the minicard, and opposing second and third lugs which each extend transversely from a longitudinal edge of the minicard,
the second and third lugs are aligned transversely and are situated close to the series of contact areas;
the second and third aligned lugs are situated approximately 17 mm from the transverse edge of the minicard from which the first lug extends;
the width of the first lug is approximately 11 mm;
the width of the second and third lugs is approximately 1.2 mm;
each of the lugs has, at least on its front face or reverse face, a groove parallel to the edge of the minicard from which the lug extends so as to constitute a portion with a reduced thickness constituting an incipient break in the lug;
the first lug has, at least on its front face or reverse face, a groove which, in cross-section, has a V-shaped profile, one leg of which, adjacent to the edge of the minicard, extends perpendicularly to the overall plane of the card;
the first lug has two identical aligned opposing grooves formed in the front face and reverse face;
each of the second and third lugs has, at least on its front face or reverse face, a groove which, in cross-section, has a V-shaped profile, one leg of which, adjacent to the edge of the minicard, extends perpendicularly to the overall plane of the card;
each of the second and third lugs has, at least on its front face or reverse face, a groove which, in cross-section, has a profile substantially in the shape of a trapezium, one edge of which, adjacent to the edge of the minicard, extends perpendicularly to the overall plane of the card and whose small base, belonging to the bottom of the groove, lies with an inclination with respect to the overall plane of the card;
each of the second and third lugs has two opposing aligned grooves, on its front face a V-shaped groove and on its reverse face a groove substantially in the shape of a trapezium.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages of the invention will emerge from a reading of the following detailed description, for an understanding of which reference will be made to the accompanying drawings, in which:
FIG. 1 is a plan view of a card according to the teachings of the invention;
FIG. 2 is a view similar to that of FIG. 1 on which the part of the card including the minicard has been depicted to a larger scale;
FIGS. 3 and 4 are views in section along the lines 3 — 3 and 4 — 4 in FIG. 2;
FIG. 5 is a view to a larger scale of the detail D 5 in FIG. 3;
FIG. 6 is a partial view in cross-section along the line 6 — 6 in FIG. 5;
FIG. 7 is a view to a larger scale of the detail D 7 in FIG. 4;
FIG. 8 is a partial view in cross-section along the line 8 — 8 in FIG. 7;
FIG. 9 is a plan view of another card according to the teachings of the invention;
FIG. 10 is a partial view in cross-section along the line 10 — 10 in FIG. 9;
FIG. 11 is a plan view of another card according to the teachings of the invention; and
DETAILED DESCRIPTION
FIG. 12 is a partial view in cross-section along the line 12 — 12 in FIG. 11 .
FIG. 1 depicts a standardized card C, of a known general design, which is a smart card consisting essentially of a body 10 in the form of a rectangular sheet with rounded corners, which is generally made from plastics material and which incorporates an electronic microcircuit (not shown) associated with the support 10 in accordance with any one of the known techniques, for example in the form of a module plugged into the support 10 .
The face 12 of the card C visible in FIG. 1 is the front face of the card, which has a zone 14 in which six or eight areas 16 , or pins, are arranged for the electrical connection of the electronic microcircuit to an operating circuit by means of an electrical connector (not shown) belonging for example to a read-write device.
The areas 16 are disposed in a standardized design and extend roughly parallel to each other and aligned in pairs in the general longitudinal direction of the card, that is to say in the direction parallel to the two parallel opposing longitudinal edges 18 and 20 of the support 10 .
In accordance with the standard, the zone 14 including the series of areas 16 is arranged close to a transverse edge 22 of the support 10 , which is referred to here as the front transverse edge with reference to the normal direction of insertion of the card C, from rear to front, into a connector.
The support 10 is also delimited by an opposite rear transverse edge 24 parallel to the front transverse edge 22 and perpendicular to the two longitudinal edges 18 and 20 .
The other face 13 forming the reverse face of the card (see FIG. 3) is parallel to the front face 12 , these two faces determining the standardized thickness of the card C, which is between 0.68 and 0.84 mm and preferably between 0.80 and 0.84 mm.
According to a known design, the support 10 has a slot F with a substantially rectangular contour and which extends roughly around a portion of the body 10 of the card C which includes the electronic microcircuit and the zone 14 including the series of electrical connection areas 16 .
The slot F thus delimits on the inside a standardized minicard MC with a substantially rectangular contour, which is delimited by two parallel and opposite longitudinal edges 26 and 28 which are respectively parallel and adjacent to the longitudinal edges 18 and 20 of the card C.
The minicard MC is also delimited by a first transverse edge 30 , here referred to as the front transverse edge, which is parallel and adjacent to the front transverse edge 22 of the card C.
Finally, the minicard MC is also delimited by another rear transverse edge 32 opposite and parallel to the front transverse edge 30 , which is an edge having a chamfer 34 formed in the front face 12 of the support 10 and which is connected to the longitudinal edge 28 by a cant 36 , with standardized shape and dimensions, in order to constitute a means of determining the direction of insertion or fitting of the minicard MC in a connector.
The function of the chamfer is to prevent any catching of the minicard against the components of a mobile telephone, when it is being removed from it. This is because some mobiles have elastic means which have a tendency to press the minicard against the connector and to lift the end 32 of the minicard out of the overall plane of the card. The chamfer can be produced by compressing the material of the card by means of an appropriate tool.
The slot F can be produced according to a known technique, using for example a cutting tool/punch and a complementary die, or by producing it by cutting by means of a pressurized water jet or a laser beam.
The cutting of the slot F is incomplete, that is to say, according to a known general design, lugs or bridges are left which connect the minicard MC to the body 10 of the card C in order to constitute a “bi-standard” assembly enabling the end user to use the large-format card C or the minicard MC, according to the application, such an option being in particular necessary when the card contains data relating to a subscription to a telephone communication network to which connection is made by portable handsets which, according to the manufacturer, use the two types of card.
The connecting lugs are produced in one piece, that is to say they are formed from portions of the support 10 which are not cut when the slot F is produced.
In accordance with the teachings of the invention, the connecting lugs are three in number and are distributed in an arrangement which will now be described in more detail, notably with reference to FIG. 2 .
The first lug B 1 extends longitudinally, towards the left looking at FIG. 2, from the front transverse edge 30 of the minicard MC which is adjacent to the zone 14 , in the direction of the front transverse edge 22 of the card C.
In accordance with the teachings of the invention, the first lug B 1 is a lug of great width L 1 , for example approximately 11 mm, which is greater than the width L 2 representing the width and passage of the contact blades of a connector with respect to the zone 14 carrying the electrical connection areas 16 . In addition, the lug B 1 extends at least opposite this zone so that there is no portion of slot F between the front transverse edge 22 of the card C and the zone 14 in order to prevent damaging the contacts of a connector by the passage of a portion of slot F over the free ends of the contact of the connector.
In addition, the first lug B 1 of great width L 1 confers mechanical properties on the card C and on the minicard MC enabling them to resist, in association with the other lugs, the torsion and bending forces mentioned previously.
The other two lugs for connecting the minicard MC to the card C are, in the embodiment illustrated in the figures, two identical and opposite lugs B 2 and B 3 .
The first lug B 2 extends transversely from the longitudinal edge 26 of the minicard MC in the direction of the longitudinal edge 18 of the card C.
In the same way, the third lug B 3 extends transversely from the longitudinal edge of the minicard MC in the direction of the longitudinal edge 20 of the card C.
The second and third lugs B 2 and B 3 are aligned in the same transverse direction and are situated close to the zone 14 , that is to say their mean transverse axis, corresponding to the section line 4 — 4 of FIG. 2, is situated at a distance from the front transverse edge 30 of the minicard MC of approximately 17 mm.
In accordance with the teachings of the invention, there is no other connecting lug, and there is in particular no connecting lug extending from the rear transverse edge 32 of the minicard MC to connect it to the support 10 of the card C, which is particularly advantageous in so far as this edge often constitutes the edge for insertion of the minicard into a connector, which thus has no burr which might impair correct positioning of the minicard with respect to the connector and might damage the contact blades on the latter.
As can be seen in particular in FIG. 2, the second and third lugs B 2 and B 3 are lugs with a reduced width L 3 , which is for example approximately 1.2 mm.
In the example illustrated in the Figures, the three lugs B 1 to B 3 are lugs each delimited by two parallel and opposite edges, of longitudinal orientation in the case of the first lug B 1 , and of transverse orientation in the case of the second and third lugs B 2 and B 3 .
According to another aspect of the invention, means are provided for facilitating the breaking of the connecting lugs by manual operation with a view to detaching the minicard MC from the card C.
In accordance with the invention, the means constituting incipient breaks for the connecting lugs are grooves with particular profiles and dimensions.
With regard to the first lug B 1 , the front face 12 and reverse face 13 of the lug each have a groove 40 , 42 which are opposite and aligned and each of which is shaped in cross-section, as can be seen in particular in FIGS. 3 and 5, with a substantially V-shaped profile.
More particularly, each groove 40 , 42 has a vertical arm or edge 44 , 46 which extends vertically perpendicular to the plane of the front face 12 and reverse face 13 , whilst the other edges or arms 48 and 49 are inclined in the direction of the card C, forming an acute angle with the edge 44 , 46 , for example of approximately 300. The depths of the grooves 40 and 42 are preferably equal but they could be different and for example equal respectively to 0.42 and 0.30 mm in the case of a 0.82 mm thick card. Preferably, the apex of the groove is broken by a flat with a width of approximately 0.02 mm or in a substantially equivalent manner by a rounded part with a radius of curvature of approximately 0.01 mm. The residual section between the grooves depends on the thickness of the card and the nature of the material making up the support. The above values are given for a card made of injection-moulded ABS or ABS-HR (high temperature) and correspond to a residual section of approximately 0.10 mm. These values would however be substantially valid for cards obtained from another injection moulded material and with similar mechanical properties.
The grooves are produced by marking by means of a punch (not depicted in the figures) whose depth of penetration determines the depth of the grooves.
As can be seen in particular in FIG. 2, the grooves forming an incipient break 40 and 42 extend over the entire width L 1 of the lug 91 .
A description will now be given of the grooves forming an incipient break for the second and third lugs B 2 and B 3 .
In the example illustrated in the figures, the grooves 50 formed in the front face 12 of the lugs B 2 and B 3 are not identical to the grooves 52 formed in the reverse face 13 . They are on the other hand identical in pairs, that is to say the two grooves 50 formed in the front face 12 are identical, just like the two grooves 52 formed in the reverse face 13 .
As can be seen in particular in FIG. 2, the width of the grooves 50 is less than the total width L 3 of the first and second lugs B 2 and 33 . The same applies to the width of the grooves 52 .
The grooves 52 forming an incipient break which are formed in the rear face 13 are of a similar design to the grooves 40 and 42 formed in the first lug B 1 , that is to say each has a profile substantially in a V shape with an edge 54 perpendicular to the overall plane of the card C and an inclined edge 56 . The angle of the V is here for example 25° and the depth of the grooves 52 is 0.10 mm. The grooves preferably have a rounded corner at their end (at the apex of the V). By virtue of this rounded part, the initiation and propagation of cracks during the bending and torsion tests in accordance with the aforementioned ISO standard are limited. This 15 rounded part has in the example in particular a radius of curvature of around 0.01 mm.
On the other hand, the groove is sufficiently profiled to permit an incipient break by an intentional manual pressure acting on the minicard in the direction in particular from the front face to the reverse face.
The grooves 50 have a different profile substantially in the shape of a trapezium, illustrated notably in FIG. 7 .
Thus each groove 50 is delimited by a base 58 slightly inclined with respect to the front face 12 and to the overall plane of the card C, for example by an angle of 10°, which corresponds to the small base 58 of the trapezium, the latter also being delimited by a large side 60 , aligned with the edge 54 of the groove 52 opposite, which extends perpendicularly to the plane of the front face 12 and to the overall plane of the large card and, on the other hand, by a small side 62 which is inclined, the first side 60 being adjacent to the minicard MC whilst the inclined (or rather slightly rounded) side 62 extends in the direction of the body of the card C. The sides 60 and 62 are connected to the base 58 by fillets with a radius of approximately 0.05 mm. As can be seen in FIG. 8, the grooves 52 and 50 have a width L 4 which is for example equal to 0.40 mm whilst the width L 3 of the lugs B 2 and B 3 is equal to approximately 1.2 mm. The width of the groove 50 for its part is equal to approximately 0.22 mm.
This groove is shaped so as to resist the bending/torsion forces imposed by the aforementioned ISO standard, and this more so than the groove 52 . This is because its rounded and open shape is more resistant to the initiation of a crack than that of the groove 52 , which has an acute shape and ends in a small radius of curvature of for example 0.01 mm, as opposed to the groove 50 whose deepest end has for example a radius of curvature greater than 0.05 mm.
The presence of a radius of curvature at the end of the groove 52 is particularly justified in order to attenuate the tendency of this groove to initiate a crack during bending/torsion tests.
A slight inclination of the base 58 of the groove 50 , for example of 10 degrees, creates a zone situated closest to the end of the groove 52 . In this way a zone 69 where a crack is initiated or arrives is obtained, facilitating the breaking of the lug along a line joining the edges 60 and 54 .
Likewise, it can be seen in FIG. 8 that the groove 50 is more splayed than the groove 52 , this again for the purpose of being less sensitive to an incipient crack compared with the groove 52 .
Thus according to the invention the card is characterized in that it has lugs for connecting the minicard to the large card with a particular shape, each lug having two types of grooves opposite each other formed so as to be sufficiently resistant to the bending/torsion forces according to the ISO standard, one of the grooves however also being formed so as more easily to initiate a crack by intentional manual pressure on the minicard. Thus, if needed, the manual effecting of the breaking is controlled as close as possible to the minicard, whilst complying with the standardized contour of the minicard.
Where necessary, it is possible to have a single lug of this type connecting the minicard to the large card and sized so as to fulfill the mechanical function of several lugs.
Where the removal of the minicard is not required, it is possible to have a large-format card in accordance with the ISO standard both with regard to the dimensions and the properties of mechanical strength.
In accordance with another embodiment illustrated in FIG. 9, the lug B 1 is produced as two lugs B 4 , B 5 spaced apart, situated notably close to the corners 70 , 71 of the minicard. These lugs can have grooves whose cross-section is substantially in accordance with that of the lug B 1 (FIG. 5 ).
The advantage of a construction with two lugs is to make it possible to keep the minicard substantially in one plane in spite of a curvature of the card in its width. In this way a probable tendency of the lug B 1 to have an incipient crack from the corners 70 , 71 is avoided.
It is however preferred to have lugs B 4 , B 5 in conformity with the lugs B 2 , B 3 in order to increase the resistance to the bending/torsion forces.
Alternatively, in order to have the least deformation on the minicard, it may be envisaged having a single lug with a structure substantially in accordance in particular with that of B 1 but less wide, and centered on the longitudinal median of the minicard. Preferably this central lug can be in accordance with B 4 , B 5 and sized so as to fulfil the required function.
The additional function of the lug B 1 , which is to facilitate the passage of resilient connector blades, can be achieved in two other different ways.
The first is illustrated in FIGS. 9 and 10, by chamfers which attenuate the discontinuity caused by the slot F. The chamfers are provided at the level of the passage of these resilient blades in the case of significant discontinuity. In the example, a chamfer ( 72 , 73 ) is provided respectively on each side of the slot F.
As a variant, the above function is achieved in accordance with FIGS. 11 and 12. Between the two lugs B 4 , B 5 there is a slot 74 passing through the card equivalent to the slot F but narrower. It can result from a shearing operation effected by blades or by punch and die.
Also as a variant, the slot F can be produced in accordance with the notch 74 in FIG. 12 over the entire contour of the minicard with the exception of the lugs.
The invention is not limited to the embodiment which has just been described.
Without departing from the scope of the invention, but preserving the principle of the invention, it is of course possible to modify the dimensions, position and number of the different lugs slightly, as well as the profiles and dimensions of the grooves.
In all cases, the design in accordance with the teachings of the invention makes it possible to meet the criteria of mechanical strength of the card without separation of the minicard, permits manual separation of the minicard MC without leaving any harmful burrs, and makes it possible to prevent premature wear on the connectors in particular when it is the large card as a whole which is used.
|
A standard size smart card has a flat support with a slot in the support to define the boundary of a minicard attached to the support by lugs. Each lug has two types of grooves opposite each other so they provide sufficient resistance to bending and flexing. One of the grooves is configured so it starts to crack when the minicard is purposely subject to pressure.
| 1
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional application No. 60/910,494, filed Apr. 6, 2007 which is incorporated by reference as if fully set forth.
TECHNOLOGY FIELD
[0002] This subject matter disclosed herein is generally related to wireless communication systems.
BACKGROUND
[0003] The IEEE 802.21 standard defines mechanisms and procedures that aid in the execution and management of inter-system handovers. IEEE 802.21 defines three main services available to Mobility Management applications, such as Client Mobile Internet Protocol (Client MIP) or Proxy MIP. Referring to FIG. 1 , these services are the Event Service 100 , the Information Service 105 and the Command Service 110 . These services aid in the management of handover operations, system discovery and system selection by providing information and triggers from lower layers 115 to upper layers 120 via a media independent handover (MIH) function 125 .
[0004] Within the context of the command service 110 , functionality is defined for querying an MIH compatible node to determine the node's Internet Protocol (IP) capabilities. This is accomplished via the MIH_Network_Address_Information Request message sent from a wireless transmit/receive unit (WTRU) and the MIH_Network_Address_Information Response message sent from the MIH compatible node.
[0005] Certain systems, such as the Third Generation Partnership Project Long Term Evolution (3GPP LTE) system, utilize a hybrid mobility schema where both client MIP and proxy MIP are used. Proxy MIP is preferred because of its well known advantages such as elimination of over-the-air (OTA) tunnelling overhead, greater flexibility, and reduced latency. However, in a roaming scenario it is highly likely that a WTRU will encounter networks that do not support proxy MIP. In this scenario, client MIP is used.
[0006] Under the current IEEE 802.21 standard, a WTRU is unable to determine whether an accessible network provides support for localized mobility procedures (such as proxy MIP) or only conventional mobility procedures (such as client MIP). This information is an important criterion in network selection. Selection of a network with undesirable mobility management procedures will result in sub-optimal mobility scenarios. Furthermore, if a WTRU is able to determine the MIP characteristics of a network, the WTRU may trigger IEEE 802.21 procedures to improve mobility handling.
SUMMARY
[0007] A method and apparatus for improving handover in IEEE 802.21 compliant communications. A query is transmitted from a WTRU to a MIH server (MIHS). The WTRU includes a target point of attachment (PoA) and/or a preferred MIP method. The WTRU receives a response from the MIHS indicating the MIP method supported by the target PoA. Based on the received response, the WTRU may make an informed decision regarding handover.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A more detailed understanding of the invention may be had from the following description, given by way of example and to be understood in conjunction with the accompanying drawings wherein:
[0009] FIG. 1 is a block diagram of MIH services;
[0010] FIG. 2 shows a wireless communication system in which a WTRU is unable to obtain mobility management information regarding diverse networks located therein;
[0011] FIG. 3 shows an enhanced network of FIG. 2 , in which a WTRU may query a MIH server and receive mobility management information regarding diverse networks located therein;
[0012] FIG. 4 is a diagram of a MIH_Network_Address_Information Request message disclosed herein;
[0013] FIG. 5 is a diagram of a MIH_Network_Address_Information Response message disclosed herein; and
[0014] FIG. 6 is a block diagram of a WTRU and an access point configured to transmit and receive the messages of FIG. 4 and FIG. 5 .
DETAILED DESCRIPTION
[0015] When referred to herein, the terminology “wireless transmit/receive unit (WTRU)” includes but is not limited to a user equipment (UE), a mobile node, mobile station (STA), a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a computer, or any other type of user device capable of operating in a wireless environment. When referred to hereafter, the terminology “access point” includes but is not limited to a Node-B, a site controller, a base station (BS), or any other type of interfacing device capable of operating in a wireless environment.
[0016] A solution to the aforementioned problem is to provide a WTRU with information regarding the MIP capabilities of a network. The network is preferably a prospective network to which the WTRU is considering a handover to. In one embodiment, a request message includes an identifier of a network that is the target network for handover. An associated response message includes MIP capabilities of the identified network.
[0017] FIG. 2 is a communication system 200 including two distinct networks 205 and 210 where mobility management information is not available to WTRU 215 . network 205 includes multiple network routers ( 220 , 225 ) and three access points 230 , 235 , and 240 . A server 245 of the first network 205 communicates with the network routers 220 , 225 and servers of other networks via the Internet 250 , for example. The second network 210 also includes a server 255 , a network router 260 , and an access point 265 . It is noted that the first network 205 and second network 210 may be of the same or different type.
[0018] In the communication system 200 , localized mobility management protocols, such as proxy MIP, are supported only in the first network 205 . When WTRU 215 is communicating with access points 230 , 235 , and 240 (locations A, B, and C, respectively), localized mobility management is available for inter-access point handovers. However, second network 210 does not support localized mobility management protocols and instead supports only client MIP. When WTRU 215 is in communication with the second network 210 (position D) via access point 265 , WTRU 215 will perform client MIP procedures, including Client originated MIP Binding Update procedures. This client MIP procedure may potentially delay handover of the WTRU 215 to access point 265 in the second network 210 .
[0019] Referring to FIG. 3 , a wireless communication system 300 includes all of the elements identified above with respect to FIG. 2 as well as an MIH server (MIHS) 305 accessible via the Internet 250 . The MIHS 305 controls various aspects of MIH and coordinates services between WTRUs and various networks. When WTRU 215 is associated with access point 240 , the WTRU 215 may query the MIHS 305 to determine the capabilities of surrounding networks. This may be achieved via the MIH_Network_Address_Information_Request message 310 , sent from the WTRU 215 to the MIHS 305 . The prospective point of attachment (PoA) in the prospective network (second network 210 ) may be identified in the message 310 , in this scenario access point 265 . In response, the MIHS 305 provides information regarding the characteristics of the prospective network (second network 210 ), such as whether proxy MIP is supported. The MIHS 305 responds to the MIH_Network_Address_Information_Request message 310 by sending a MIH_Network_Address_Information_Response message 315 including the requested information.
[0020] Alternatively, the MIH_Network_Address_Information Request message 310 may simply indicate the MIP preferences of the WTRU 215 . In this scenario, the MIHS 305 will identify networks that are capable of supporting the WTRU's 215 MIP preference. Based on the information received from the MIHS 305 in the MIH_Network_Address_Information_Response message 315 , the WTRU 215 may choose access point 240 or access point 265 , depending on supported MIP services and preference.
[0021] Referring to FIG. 4 , the MIH_Network_Address_Information Request message 400 includes a Source ID field 405 , a Destination ID field 410 , a Current Link ID field 415 , a New PoA Identifier field 420 , a Target PoA Identifier List field 425 , a Current IP Configuration Method field 430 , a Current dynamic host control protocol (DHCP) Server Address field 435 , a Current Foreign Agent (FA) Address field 440 , a Current Access Router Address field 445 , and a Requested MIP Mobility Method field 450 .
[0022] The Source ID field 405 indicates the originator of the message. The Destination ID field 410 indicates a remote MIH function that will be the destination of the request. The Current Link ID field 415 indicates the source link for handover. The New PoA Identifier field 420 indicates a new point of attachment identity. The Target PoA Identifier List field 425 includes a listing of potential points of attachment that the WTRU is considering for handover. Optionally, the list of potential points of attachment is sorted by preference, with most preferred points of attachment listed ahead of least preferred. The Current IP Configuration Method field 430 indicates current IP configuration methods. In one embodiment, this field is an optional field. The current DHCP Server Address field 435 indicates the IP address of a current DHCP Server. In one embodiment, this field is only included when the WTRU is using a dynamic address configuration. In another embodiment, this field is optional. The Current Foreign Agent (FA) Address field 440 indicates the IP address of a current FA. In one embodiment, this field is only included when the WTRU is using MIPv4. The Current Access Router Address field 445 indicates the IP address of a current access router. In one embodiment, this field is only included when the WTRU is using IPv6. In another embodiment, this field is optional. The Requested MIP Mobility Method field 450 identifies a WTRU preferred MIP mobility method. The MIH_Network_Address_Information Request message 400 may include all of the above described fields, or any sub-set of these fields, in any combination.
[0023] In one embodiment, the Requested MIP Mobility Method field 450 includes a Proxy Mobile IPv6 indicator at bit 14 . Table 1 below illustrates one embodiment of the Requested MIP Mobility Method field 450 .
[0000]
TABLE 1
Requested
Bit
Bits 0-31
Bit 0: IPv4 static
MIP Mobility
map
Bit 1: IPv4 dynamic
Method
Bit 2: Mobile IPv4 with FA (FA-
CoA)
Bit 3: Mobile IPv4 without FA
(Co-located CoA)
Bits 4-10: Reserved for IPv4
address configuration
Bit 11: IPv6 stateless address
configuration
Bit 12: IPv6 stateful address
configuration
Bit 13: IPv6 manual
configuration
Bit 14: Proxy Mobile IPv6
[0024] Referring to FIG. 5 , the MIH_Network_Address_Information Response message 500 includes a Source ID field 505 , a Destination ID field 510 , a Current Link ID field 515 , a New PoA Identifier field 520 , an IP Configuration Method field 525 , a DHCP Server Address field 530 , an Access Router Address field 535 , and a Result Code field 540 .
[0025] The Source ID field 505 indicates the originator of the message. The Destination ID field 510 indicates a MIH function that will be the destination of the message (i.e., the WTRU MIH). The Current Link ID field 515 indicates the source link for handover. The New PoA Identifier field 520 indicates the point of attachment of a new access network to which handover initiation is considered. The IP Configuration Method field 525 indicates the IP configuration method of the point of attachment identified in the PoA Identifier field 510 . The DHCP Server Address field 530 indicates the DHCP server IP address of the point of attachment identified in the PoA Identifier field 510 . The Access RouterAddress field 535 indicates the IP address of the access router associated with the point of attachment identified in the PoA Identifier field 510 . The Result Code field 540 indicates a result code associated with the message. The MIH_Network_Address_Information Response message 500 may include all of the above described fields, or any sub-set of these fields, in any combination.
[0026] In one embodiment, the IP Configuration Method field 525 includes a Proxy Mobile IPv6 indicator at bit 14 . Table 2 below illustrates one embodiment of the IP Configuration Method field 525 .
[0000]
TABLE 2
IP
Bit
Bits 0-31
Bit 0: IPv4 static
Configuration
map
Bit 1: IPv4 dynamic
Method
Bit 2: Mobile IPv4 with FA (FA-
CoA)
Bit 3: Mobile IPv4 without FA
(Co-located CoA)
Bits 4-10: Reserved for IPv4
address configuration
Bit 11: IPv6 stateless address
configuration
Bit 12: IPv6 stateful address
configuration
Bit 13: IPv6 manual
configuration
Bit 14: Proxy Mobile IPv6
[0027] Proxy MIP is currently defined as Network-based Localized Mobility Management (NETLMM) support for internet protocol version 6 (IPv6) capable networks. However, the evolution of NETLMM will likely lead to support of legacy internet protocol version 4 (IPv4) networks. In another embodiment, support of IPv4 proxy MIP may be indicated in the messages described above. This would similarly allow a WTRU to select the best handover target during network selection. Additional reserved bits could be used to request and advertise IPv4 functionality.
[0028] FIG. 6 is a WTRU 600 and access point 605 configured to transmit and receive MIH_Network_Address_Information Request and MIH_Network_Address_Information Response messages, as described above. WTRU 600 includes a processor 610 , an MIH function 615 , and a plurality of transceivers 620 a . . . 620 n . The processor 610 and MIH function 615 are configured to generate and process a MIH_Network_Address_Information Request message as described above. The plurality of transceivers 620 a . . . 620 n are configured to communicate in a plurality of different types of wireless communication systems using various radio access technologies, and to transmit a MIH_Network_Address_Information Request message as described above.
[0029] Access point 605 includes a processor 625 , an MIH function 630 , and a transceiver 635 . The access point 605 communicates with WTRU 600 via air interface 640 . The processor 625 of the access point 605 processes received MIH_Network_Address_Information Request message from WTRU 600 via air interface 640 and transceiver 635 . The processor 625 , in combination with the MIH function 630 , of access point 605 forwards received MIH_Network_Address_Information Request message to MIHS 645 and receives MIH_Network_Address_Information Response messages from the MIHS 645 . Received MIH_Network_Address_Information_Response messages are forwarded to the WTRU 600 via air interface 640 .
[0030] Although the features and elements of the present invention are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the embodiments or in various combinations with or without other features and elements of the present invention. The methods or flow charts provided in the present invention may be implemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of computer-readable storage mediums include a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs).
[0031] Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and/or a state machine.
[0032] A processor in association with software may be used to implement a radio frequency transceiver for use in a wireless transmit receive unit (WTRU), user equipment (UE), terminal, base station, radio network controller (RNC), or any host computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated (FM) radio unit, a liquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and/or any wireless local area network (WLAN) module.
|
A method and apparatus for improving handover in an IEEE 802.21 compliant communication network. A query is transmitted from a wireless transmit/receive unit (WTRU) to a media independent handover (MIH) server (MIHS). The WTRU includes a target point of attachment (PoA) and/or a preferred mobile inter protocol (MIP) method. The WTRU receives a response from the MIHS indicating the MIP method supported by the target PoA. Based on the received response, the WTRU may make an informed decision regarding handover.
| 7
|
[0001] This application claims priority to provisional patent application Ser. No. 61/162,890, filed Mar. 24, 2009.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a pocketknife puzzle or kit for making a pocketknife. The component parts may be assembled into a pocketknife, useful as a toy, letter opener or the like, and then disassembled again, as desired.
[0003] Pocketknives useful as tools are well known in the prior art. The blade, spring and handles are made of metal. Rivets are employed to hold the component parts together. The pocketknives are sold assembled and are intended to remain assembled. Such a pocketknife may be disassembled only with difficulty, such as by removing the rivets with a punch, thereby damaging or destroying them.
[0004] Prior art toy pocketknives have typically been sold pre-assembled and are not intended to be disassembled. Furthermore, many toy pocketknives lack features, such as a spring, to engage the pivoting end of the blade and hold the blade in a desired position, for example, open or closed.
SUMMARY OF THE INVENTION
[0005] The present invention is a three-dimensional puzzle or kit for making a pocketknife. The component parts of the pocketknife are a blade, a spring, first and second handle sections and three cylindrical fasteners. The blade has a pivoting end, with a hole therein, and a swinging end, opposite the pivoting end. The pivoting end of the blade may have a cam-shaped outer surface (cam surface). The blade need not be pointed at the swinging end or sharp, but it can be pointed and sharpened, as desired.
[0006] The spring has an anchoring end, with a first hole therein, a deflecting end, opposite the anchoring end, and a second hole, positioned between the anchoring end and the deflecting end. The deflecting end of the spring is urged against the pivoting end of the blade, when the pocketknife is assembled.
[0007] The handle of the pocketknife is in two sections. The first handle section has a first end, with a first hole therein, a second end, opposite the first end, with a second hole therein, and a third hole, positioned between the first and second holes. The second handle section has a first end, with a first hole therein, a second end, opposite the first end, with a second hole therein, and a third hole, positioned between the first and second holes. Three cylindrical fasteners are provided, which are configured to engage the first, second and third holes in the first and second handle sections.
[0008] When the pocketknife is assembled, the blade and spring are sandwiched between the first and second handle sections. One of the cylindrical fasteners extends through the first holes in the handle sections and the hole in the pivoting end of the blade. The second cylindrical fastener extends through the second holes in the handle sections and the hole in the anchoring end of the spring. The third cylindrical fastener extends through the third holes in the handle sections and the second hole in the spring.
[0009] In one embodiment of the invention, the cylindrical fasteners are selected to allow the pocketknife to be assembled and disassembled, multiple times and without damage to the fasteners. By way of example, the cylindrical fasteners may be metal pins or bolts, the bolts having a threaded end to engage a nut. The use of pins has the advantage that the component parts may be assembled to make a pocketknife, and disassembled again, without the use of tools. The pins are held in place solely by frictional engagement, as the spring is under tension itself and the spring applies tension to the pivoting end of the blade.
[0010] In one embodiment of the invention, the blade, spring, first and second handles, and first, second and third cylindrical fasteners are provided unassembled in a package. This provides a child with the challenge of assembling the component parts to make a pocketknife, by following the instructions provided therewith. Preferably, the package is re-usable and is proportioned to store both the unassembled component parts or the assembled pocketknife.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an exploded view of the pocketknife.
[0012] FIG. 2 is a perspective view of the assembled pocketknife.
[0013] FIG. 3 is a perspective view of an alternative embodiment of the cylindrical fasteners used to hold the pocketknife together, namely bolts and nuts.
[0014] FIG. 4 is an example of suitable packaging for the component parts of the pocketknife, namely a re-usable tin box.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Without intending to limit the scope of the invention, the preferred embodiments and features are hereinafter set forth.
[0016] FIG. 1 is an exploded view showing the individual component parts of the pocketknife puzzle and how the components fit together. Blade 1 has a swinging end 2 and a pivoting end 3 , shown with a point. Pivoting end 3 has a hole 4 and a cam surface 5 .
[0017] Spring 6 has an anchoring end 7 and a deflecting end 8 . Spring 6 has a first hole 9 in the anchoring end 7 and a second hole 10 between the anchoring end 7 and the deflecting end 8 . The first hole 9 and second hole 10 are spaced apart to provide leverage, when the parts are assembled, whereby deflecting end 8 may be resiliently deflected, but spring 6 does not pivot about hole 10 .
[0018] Blade 1 and spring 6 are sandwiched between handle sections 11 and 12 , whereby deflecting end 8 of spring 6 is urged against cam surface 5 , as blade 1 is pivoted. The force applied to the pivoting end 3 of blade 1 by spring 6 holds blade 1 in position (closed or open), as well as creates sufficient force to frictionally engage pin 13 , which is inserted through holes 14 and 15 in handles 11 and 12 , respectively, and hole 4 in blade 1 .
[0019] Pin 16 is inserted through hole 17 in handle 11 , hole 9 in spring 6 and hole 18 in handle 12 . Pin 19 is inserted through hole 20 in handle 11 , hole 10 in spring 6 and hole 21 in handle 12 . The force applied to the deflecting end 8 of spring 6 by the pivoting end 3 of blade 1 is transmitted along spring 6 creating sufficient force to frictionally engage pins 16 and 19 , when the parts are assembled.
[0020] Optionally, inlays 22 and 23 are provided, which conform to recesses in the outer surfaces of handles 11 and 12 , respectively. Inlays 22 and 23 are provided with holes 24 and 25 , respectively, which allows the inlays to fit over pin 19 . Inlays 22 and 23 are not frictionally engaged by pin 19 , but can be glued to the handles.
[0021] Referring to FIG. 2 , the assembled pocketknife 26 is shown. In one embodiment of the invention, each of pins 13 , 16 and 19 is a metal rod having a uniform diameter along its length. Accordingly, the pins and other parts of the pocketknife (blade, spring and handles) can slide relative to each other, allowing the pocketknife to be assembled and disassembled without tools, and without damaging the pins.
[0022] In an alternative embodiment, pins 13 , 16 and 19 may be replaced by bolts 27 and nuts 28 , shown in FIG. 3 . For example, nuts 28 may be inserted in handle 11 or 12 , to facilitate assembly. The bolts 27 can be unscrewed to disassemble the knife, as desired, without damaging the bolts and nuts. The cylindrical fasteners may also be a non-metal dowel or peg, or metal cotter pin.
[0023] The blade, spring and handles may be made of the same or different material. By way of example, the material of construction for the blade, spring and handle may be selected from wood, thermoplastic resin, thermosetting resin or metal. The resin may be a composite, having a filler or fiber reinforcement incorporated therein. Wooden parts may be manufactured using a computer guided laser or router. For use as a child's puzzle, the blade, spring and handle are preferably non-metal.
[0024] The parts of pocketknife 26 can be sold unassembled in a package. The term “package” is intended to encompass containers, such as a tin box 29 , shown in FIG. 4 and other re-usable metal, textile and synthetic resin containers, which can accommodate all of the parts or the assembled pocketknife, as well as disposable packaging such as plastic bags or molded plastic sheets.
[0025] Optionally, the pocketknife kit components can be glued together for permanency. The blade can be left dull or can be sharpened to a point. The blade may be waxed for ease of opening and closing of the blade. The components may be painted, stained or varnished before or after assembly.
[0026] The invention may be further understood by reference to the following claims.
|
A pocketknife puzzle or kit is provided having a blade and spring, sandwiched between two handle sections and held in place by three pins. The pins are held in place by friction, resulting from the tension of the spring against the pivoting end of the blade. The pocketknife may be assembled and disassembled without tools.
| 1
|
BACKGROUND OF THE INVENTION
The present invention relates to a building structure and more particularly relates to part of a building structure that constitutes a ceiling/floor or a ceiling/roof assembly.
The present invention will be described with reference to a method of building that utilises pre-formed components that can be rapidly assembled together, an inter-space defined by the assembled components being filled with a foam material. However it is to be appreciated that the invention is not restricted to such a specific use.
BRIEF SUMMARY OF THE INVENTION
According to this invention there is provided a ceiling/floor or ceiling/roof structure comprising a plurality of substantially parallel substantially horizontally extending joists, each joist being supported at the two opposed ends thereof, a first set of transverse members resting on the top of and secured to the top of at least some of said joists, and a further set of transverse members extending underneath and connected to the lower surfaces of at least some of said joists, the said structure being adapted to be associated with ceiling and/or roofing or flooring materials.
In one embodiment all the joists lie in a common plane and said first set of transverse members and said further set of transverse members all contact all of the joists and are secured thereto.
In an alternative at least some of the joists are inclined upwardly relative to the remaining joists so that the inclined joists extend above said remaining joists, said first set of transverse members being connected to the upper surfaces of the said inclined joists and said lower set of transverse members being connected to the undersides of the remaining joists.
Preferably each joist comprises two substantially "c" sectioned channel members made of metal and mounted back-to-back.
Conveniently the abutting portions of said channel members are apertured to minimise the weight of the joists.
Advantageously each said transverse member comprises a member of substantially "top hat" cross section thus comprising two substantially horizontal flanges having free edges, and a central raised portion connected by two substantially vertical or sloping portions with the other edges of said flanges.
Preferably the said two flanges of each transverse member are connected to the upper or lower surfaces of the relevant joists.
In one embodiment said joists are supported by channel members extending transversely to the ends of the joists.
Preferably the space or at least part of the space between the joists is filled with a thermally insulating foam material.
Conveniently said foam is a substantially rigid foam which improves the load bearing properties of the ceiling/roof or ceiling/floor structure.
INTRODUCTION TO THE DRAWINGS
In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of part of a building, whilst under construction;
FIG. 2 is a sectional view taken on the line II--II of FIG. 1.
FIG. 3 is a perspective view of part of an elongate member utilised in forming the described structure;
FIG. 4 is a corresponding view of part of another elongate member utilised in forming the structure;
FIG. 5 is a corresponding view of part of an assembly of two elongate members as shown in FIG. 4;
FIG. 6 illustrates the junction between the supports for the described ceiling/floor assembly at one corner of a building;
FIG. 7 illustrates a connection between a horizontal member and a support joist forming part of the described ceiling/floor assembly;
FIG. 8 is a perspective view of part of a completed ceiling/floor assembly;
FIG. 9 is a perspective view of part of a ceiling/roof assembly providing a sloping flat roof;
FIG. 10 is a plan view of the ceiling/roof assembly of FIG. 9; and
FIG. 10A is a horizontal section view taken along the line 10A--10A of FIG. 10.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring initially to FIG. 1 a wall of a building is illustrated. The wall is effectively secured to a concrete raft (not shown) by means of a fastening bracket 1. Vertical members 2 are connected to the brackets 1, and horizontal members 3 are also connected between the adjacent backets 1. Further vertical members 4 are connected to the horizontal members 3 by means of brackets 5. The brackets 5 are each of "U" configuration, the flat base of the "U" being secured to the horizontal member 3, and the two upstanding arms of the "U" embracing the lowermost portion of each vertical member 4. A similar, but inverted, bracket 6 is provided at the top of the vertical member 4. Brackets 7, corresponding to the brackets 5, are utilised to connect further horizontal members 8 to the upright members 2 at positions spaced above the horizontal members 3. The brackets 6 provided at the upper end of the vertical member 4 serve to interconnect that vertical member 4 to the appropriate horizontal member 8.
A further vertical member 9 can be connected to the horizontal member 8 by means of a further brackets 10 which corresponds with the brackets 5 described below.
It will thus be appreciated that a framework can be created, and the framework will effectively define the outer walls of the building.
As can be seen most clearly from FIG. 2 each of the upright members 2 is formed as a hollow cold rolled lock seamed tube formed from hot dipped galvanised mild steel or stainless steel, or aluminum. Each tube is of substantially square cross section, but two elongate recesses are formed in two opposed faces of the tube so that the tube is of generally "H" cross section and the lock seam 12 is located in the base of one of these recesses. The tube is entirely filled with a substantially rigid foamed plastics material 13 which may be a polyurethane foam or any other appropriate foam. A tube of this construction may be fabricated from relatively thin galvanised mild steel or stainless steel, or aluminium but will have substantial strength and will also have excellent thermal insulation properties by virtue of the foam filling for the tube.
One surface of each wall of the complete framework is provided with a sheet 11 of appropriate material, and it is most preferred that the sheet is of translucent polyethene, and may be a cross laminate of oriented high density polythene as sold under the Trade Mark "VALERON" by Van Leer (U.K.) Limited of Ellesmere Port, Livepool, or a spunbonded polyolefin sheet, such as sold under the Registered Trade Mark "TYVEK", especially grade 1043B by Wiggins Teape Synthetics of Basingstoke, Hampshire. The sheet is secured in position to extend across all the apertures defined by the framework, and is preferably located on the exterior of the framework so that the sheet then defines the outermost surface of the structure. The sheet may be held in position by means of double sided adhesive tape 14 utilised to secure the sheet to the vertical members 2 and the horizontal members 3 and 8.
A sprayed foam material, such as sprayed polyurethane foam or sprayed polyisocyanurate foam may then be sprayed, from the interior of the framework, on to the polythene sheet. An initial thin spray of foam is applied which, as a result of the heat generated during the foaming process, bonds firmly to the polythene sheet and rapidly cures or solidifies. One or more subsequent layers of foam can be provided until the entire inter-space defined by the frame members and the polythene sheet is filled with foam material 15, apart from those regions of the framework that are intended to define apertures to accommodate doors or windows. The inner surface of the foam 15 is made flush with the inner surfaces of the various frame members. Internal cladding, such as conventional dry lining, can be mounted in position on the interior of the walls and an appropriate external cladding can be provided.
The insulating foam utilised may be any convenient foam, but reference may be made to a polyurethane foam, the components of which are sold under the Trade Mark Trade Mark "ISOFOAM" by the Baxendon Chemical Company Limited of Accrington, Lancashire. The foam is created by mixing an isocyanate and a polyol. Grade SS212 may be found suitable for spraying and grade RM114 may be found suitable for injection into the hollow box sections constituting the frame members. Such a foam may easily be treated to have good fire resistance properties. Another suitable foam is that known as the Coolag Toucan System CSS 732 which is a two component polyethylene spray foam system, in which one component is a resin blend containing polyol, catalysts, a fire retardant and a blowing agent and the other component is a polymeric isocyanate. The components for making this foam are sold by Coolag Limited of Charlestown, Glossop, Derbyshire. However, alternatively, phenolic resin based foams may be used which may have extremely good, class O, fire resistance properties.
It is to be noted that the lock seams 10 of the various members forming the framework are so located that when the foam material 15 has been sprayed onto the polythene sheet 11 the foam material covers the lock seam 12, thus minimising any risk of corrosion commencing at this point.
FIG. 3 illustrates an elongate metallic member that forms part of the ceiling/floor structure to be described. The elongate member 16 is of "top hat" cross-section. The member has a central elevated planar portion 17 joined by two downwardly inclined connecting portions 18 with two outwardly directed horizontal flanges 19, these flanges being parallel with the planar portion 17 but spaced therefrom. Connecting holes 20 are formed in the flanges 19 at the desired locations. These connecting holes are dimensioned to accommodate rivets, as will be described hereinafter.
FIG. 4 illustrates another elongate member 22 that forms part of the structure to be described. This elongate member comprises a substantially "C" section channel member having a primary vertical wall 23 carrying, at its top and bottom side edges inwardly directed upper and lower horizontal flanges 24, 25. These flanges terminate respectively in downwardly and upwardly inclined lips 26, 27. The vertical wall 23 is extended at one end of the element to form a protruding tongue 28. This tongue is provided with connection apertures 29. Appropriate apertures, not shown, are provided at desired locations along the length of the elongate member 22 both in the vertical wall 23 and in the two horizontal flanges 24, 25.
FIG. 5 shows two elongate elements 22 as shown in FIG. 4 mounted back-to-back, with the vertical walls 23 of the two members abutting. The elongate members are interconnected by means of rivets passing through aligned holes (not shown) in the abutting vertical walls 23.
Turning now to FIG. 6, the interconnection between vertical members 2 and horizontal members 8 as described above with reference to FIG. 1 can be seen, and part of the brackets 7 are visible. It will be noted that elongate members 22 are connected to the horizontal members 8 by means of appropriate rivets (not shown), and also the protruding tongues 28 of these members are connected to the vertical members 2 by means of appropriate rivets. A small infill member 29 is provided which comprises merely a short section of a channel member having the same configuration as the elongate member 22, but not having the end tongues. This infill portion 29 is mounted in position by means of the rivets that pass through the tongue the co-aligned channel member 22.
It will be appreciated that similar constructions will be provided at the four corners of an area that is to be supplied with a ceiling/floor assembly.
A plurality of joists are then mounted in position, as can be seen most clearly in FIG. 7. The joists all extend in a parallel manner across the space where the ceiling/floor assembly is to be provided. Each joist 30 is constituted by an assembly of two elongate members 22, mounted back-to-back. The protruding tongues provided at the ends of the members extend into the space defined by the channel member 22 that is connected to the horizontal member 8. At this point it is to be noted that the horizontal member 8 is effectively formed by the combination of two members for additional strength. The joist 30 is held in position in the channel 22 by means of two "L" shaped brackets 31, each of the said brackets having one arm thereof rivetted to the channel member 22 and thus also to the horizontal member 8, the other arm of the "bracket" being bolted to the protruding tongue 28 provided at the end of the joist 30 by means of an appropriate bolt or rivet 32.
A portion of the elongate member 16 is then rivetted into position on top of the uppermost flange 24 of the channel member 22 secured to the horizontal member 8, and resting on the uppermost flange of the joist 30. Appropriate apertures are formed in the flanges to receive rivets or the like.
FIG. 8 illustrates merely the ceiling/floor assembly that is presently being described, and thus illustrates the outer peripheral channel members 22, but does not illustrate the horizontal members 8 that are actually supporting the channel members 22. This is for clarity of illustration, but it is to be appreciated that the illustrated channel members 22 would always be supported by appropriate horizontal members before the floor assembly could be created.
As can be seen in FIG. 8 a plurality of horizontal joists 30 have been mounted in position. Extending transversely of the joists 30 are a plurality of parallel elongate transverse members 16, these members being located on top of the joists with the flanges 19 thereof in contact with the joists. The elongate transverse members 16 are connected to the joists at the points of contact by appropriate rivets. Further elongate transverse members 16 extend, in alignment with the member 16 on top of the joists, on the undersides of the joists. Again the flanges 19 of the elongate member 16 are in contact with the joists and are connected thereto by means of rivets.
The resultant floor structure is extremely strong, even though it is made with relatively light weight components. Also the floor is able to withstand a very high floor loading at any selected point, since the load will rapidly be spread by the described structure and will thus be absorbed by a number of joists.
When the structure has been completed either flooring or ceiling material may be mounted in position on either the top or the bottom of the structure, and the interspace between the joists may then be filled or at least partly filled with foam, in a manner as described above.
FIG. 9 illustrates a ceiling/roof assembly. It can be seen that the illustrated arrangement is very similar to the arrangement illustrated in FIG. 8. A plurality of horizontal joists 30 are provided, and elongate transverse members 16 are secured to the underside of these joists. Interposed between the joists 30 are a plurality of inclined joists 40 which are inclined upward relative to and extend above the horizontal joists 30, and elongate transverse members 16 are connected to the tops of these inclined joists. Thus the elongate members 16 on the undersides of the horizontal joists can be utilised to support a flat ceiling, whereas the elongate members 16 on top of the sloping joists 40 can be utilised to support a sloping roof. It will be appreciated that the precise configuration of the horizontal member supporting the ends of the joists is modified to enable the ends of the joists 30 and 40 to be spaced apart in a vertical sense. Again it is to be appreciated that the interspace between the joists may be filled with a suitable foam material.
|
A ceiling/floor or ceiling/roof structure comprising a plurality of substantially parallel substantially horizontally extending joists, each joist being supported at the two opposed ends thereof, a first set of transverse members resting on the top of and secured to the top of at least some of said joists, and a further set of transverse members extending underneath and connected to the lower surfaces of at least some of said joists, the said structure being adapted to be associated with ceiling and/or roofing or flooring materials.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001]
[0000]
Application
Number
Filing Date
Relationship of Application
20020079645
June 2002
Portable Bag Toss Game
20050023762
February 2005
Corn Bag Toss Game
20050127609
June 2005
Game Tossing Objects into Box
20060125186
June 2006
Bag Toss Game Target Assemblies
20080042360
February 2008
Hybrid Bag Toss and Card Game
20040188942
September 2004
Non-Alcoholic Beer-Pong Game
20050029747
February 2005
Drinking Game Cup Holder
20060065665
March 2006
Portable Cooler and Table
20070107460
May 2007
Cup Holder For Drinking Game
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable
BACKGROUND OF THE INVENTION
[0004] The Play-ble Recreational System will be used for recreational or entertainment purposes, and more specifically, the invention will primarily be used to play the lawn games popularly known as cornhole and beer pong. Cornhole and beer pong games have been played in the United States for many years using a variety of different names. In most cornhole games, players take alternating turns, each attempting to toss four sealed beanbags one at a time, through a hole in a stationary game assembly that is resting on the ground. Typically, two game assemblies are used, spaced approximately twenty-seven feet away from the players, with each game's playing platform tilted at an approximate 45° angle towards each of the players with respect to the ground on which the target is resting.
[0005] Cornhole can be played using a variety of rules. According to the American Cornhole Association, players are awarded three points for every beanbag that is tossed directly into or knocked entirely through the hole in the playing platform of each assembly, and one point for beanbags that land and remain on the playing platform but do not pass entirely through the hole in the platform. No points are awarded for beanbags that do not pass through the hole in the assembly or remain on the playing platform. Games are usually played until one of the players or a team of two players accumulates twenty-one points, but the player(s)' can decide to play until they reach any number of points.
[0006] Beer pong is a game that requires the use of some sort of tabletop and generally twelve wide mouth cups. Six cups are filled with equal portions of liquid, typically beer, and are aligned in a horizontal pyramid on the farthest ends of the table. Players on one side of the table attempt to throw or bounce a ping-pong ball into one of their opponent(s)' cups in the array on the other side of the table. If the ping-pong ball lands in any of the cups, one of the opponent(s) on that side of the table must drink the liquid in that cup and remove the cup from play.
BRIEF SUMMARY OF THE INVENTION
[0007] The object of the Play-ble Recreational System is to provide a multifunctional and portable device, which can be used to play cornhole and beer pong or be used as entertaining/dining table.
[0008] The present invention is comprised of two separate assemblies. The top surface of each assembly includes at least one through-aperture, approximately six inches in diameter, which is large enough to allow a beanbag to pass entirely there through. Attached to the underside and at the rear of each assembly, closer to the through-aperture, is a small collapsible leg mechanism (hereinafter referred to as “gaming leg mechanism”) approximately twelve inches in length is attached, and when extended, allows each assembly to be angled toward the players, so that the game of cornhole may be played.
[0009] In addition to the gaming leg mechanism, the underside of each assembly is also equipped with two longer collapsible leg mechanisms (hereinafter called “table leg mechanisms” if referred to collectively), one in the front and one in the rear of each assembly. These table leg mechanisms allow assemblies to be able to transform into freestanding independent tables. Furthermore, once the assemblies have been transformed into separate tables, they can be joined end-to-end to form an elongated table, approximately seven-feet long, which can be used to play beer pong or serve as a dinning/serving table with the through-apertures at opposite ends of the table. Alternatively and additionally, the tables can be connected perpendicularly to one another to from an L-shaped buffet/serving table. When the present invention is in any one of the table variations, individual tables, L-shaped table, long dinner/ serving table, or beer pong table, the through-apertures on the surface of each assembly can be plugged with plastic cover caps, thus creating a hole-free and completely solid surface. There are also optional attachments, other than the plastic cover caps, that will ultimately be manufactured for the invention that can be placed within the through-apertures in the tables such as ice buckets, condiment trays, trashcans, etc.
[0010] Another object of the present invention is to make the device portable and easy to transport. To achieve this goal, the assemblies will be constructed so that all of the leg mechanisms table and gaming leg mechanisms can be folded and secured underneath the assembly. Once this is done, the leg mechanisms will be completely hidden within the assemblies. The end result is that each assembly is only about two inches in depth. After the assemblies have been folded into this compact state, the assemblies can be stacked on top of one another and placed within a carrying/travel bag. This will allow the entire Recreational System to be easily stored and transported.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0011] FIG. 1 is an aerial view of the surface of the two separate target assemblies and detachable caps, as they would appear if laid flat on the ground with all legs folded flat inside the assembly.
[0012] FIG. 2 is an aerial view of the underside of one of the target assemblies, as it would appear if laid flat with its surface against the ground and all legs folded flat inside the assembly.
[0013] FIG. 3 is the same view aerial viewpoint depicted in FIG. 2 , illustrating both assemblies side by side in their most compact and portable states.
[0014] FIG. 4A is a section view showing a portion of the assembly shown in FIG. 2 and 3 , specifically showing one of the table legs being extended out from the side of the assembly.
[0015] FIG. 4B is an alternate position of the table leg shown in FIG. 4A and specifically shows how the bracket will break and rotate to allow the table leg to fold into the assembly.
[0016] FIG. 5 is a section view showing the top right corner of the assembly shown in FIG. 2 , specifically showing where the table legs and brackets will be situated and how they will be attached to the assembly and to each other.
[0017] FIG. 6A is a perspective view of one of the assemblies, taken from a side view to show the assembly with its legs extended, thus creating a table.
[0018] FIG. 6B is the same assembly shown in FIG. 6A , but taken as to show the rear of the table.
[0019] FIG. 7A is an aerial and sectional view showing the protruding and receiving mechanisms found in FIG. 1 that will most likely be used to connect the two assemblies. More specifically in regards to FIG. 1 , the protruding mechanism 42 is a sectional view of the left corner of 41 on assembly 15 , and the receiving mechanism 44 or 32 is a sectional view of the right corner of 43 ′ or the bottom corner of 31 of assembly 20 respectively.
[0020] FIG. 7B is the same sectional view and assemblies shown in FIG. 7A , and shows the protruding mechanism being fully and completely enveloped in the receiving mechanism as a result of the protruding assembly 15 being pushed together with the receiving assembly 20 .
[0021] FIG. 7C is the same sectional view and assemblies shown in FIG. 7A and 7B , and shows the tables locked and connected as the result of the protruding assembly 15 being slide upward into the remaining portion of the receiving mechanism on assembly 20 .
[0022] FIG. 8A is a perspective side view of the assemblies locked together end to end to create a beer pong or dinning table.
[0023] FIG. 8B is an aerial view of the assemblies shown in FIG. 8A .
[0024] FIG. 9A is a perspective view of the assemblies locked together perpendicularly to create the L-shaped buffet or serving table.
[0025] FIG. 9B is an aerial view of the figures shown in FIG. 9A .
[0026] FIG. 10A is a perspective rear of one of the assemblies, as it would appear during game play.
[0027] FIG. 10B is a perspective side view of one the assemblies, as it would appear during game play.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention will now be described in detail, with reference to the drawings that supplement this application. It should be noted that the attached drawings represent only one of many possible embodiments of the invention and should not be limited to or understood to be the only possible embodiment of the invention.
[0029] The use and assembly of the present invention will be described using FIGS. 1-10B . The invention is intended to be a portable and multifunctional entertainment device that can serve as a dinner/entertaining table, cornhole game, and beer pong table. While the top and side surfaces of the invention may ultimately be composed of a wide variety of different materials, they will most likely be constructed out of a rigid material, such as plywood or heavy duty plastic, so that the device can be sturdy enough to support substantial weight when used as a table. Also, when the invention is used to play cornhole, these types of rigid materials help the top surface of the assembly absorb the impact of the beanbags without causing the bags to ricochet off the assembly. Finally, the durability of plywood and plastic allows the invention to be used equally well both indoors and outdoors and withstand harsh treatment.
[0030] FIG. 1 is an aerial view of the invention referenced as 10 . This illustration shows the top surfaces of the two individual assemblies referenced as 15 and 20 . The dimensions and construction of assemblies 15 and 20 are identical in almost every way except for a few key differences, specifically the connecting mechanisms 42 , 44 and 32 , which will be discussed shortly. While the exact dimensions of the invention 10 are not essential to the construction or use of the invention 10 , they are included in this writing so as to give the examiner a better understanding of size of the assemblies 15 and 20 . The dimensions set forth here should not be understood or construed to be the only suitable dimensions of the invention; they are simply the inventors' best estimates of the optimal size of each assembly. This being said, the dimensions of each assembly 15 and 20 are approximately twenty-four inches wide 40 , 41 , and 43 , by forty-four inches long 30 and 31 . All of the aforementioned sidings of the assemblies 15 and 20 have an approximate depth of two inches. Both the left and right sides 30 of the male assembly 15 and the right side 30 of the female assembly 20 are constructed out of solid pieces of rigid siding, as are the rear sides 40 of both assemblies. The composition of the left side 31 of the female assembly 20 is primarily one solid piece of rigid siding, except for the two hollow cut outs 32 that will serve as connecting mechanisms (hereinafter referred to as female connector pieces). The function of these female connector pieces 32 is to allow a male assembly 15 to connect to the assembly 20 on which the female connector pieces 32 are attached, thus creating and L-shaped table. The specifics of the L-shaped table and connecting procedure will be analyzed in detail in FIGS. 7 and 9 .
[0031] The front side 43 of the female assembly 20 looks and functions almost identically to the left side 31 of the assembly, with the length of the sides being the only difference between the two. Like the left side 31 of the female assembly 20 , the front side 43 is fitted with two female connector pieces 44 which allow a male assembly 15 to connect end-to-end with the female assembly 20 , thus forming a long table which can be used as a dinning/serving table or as a beer pong table. The specifics of the dinning table/beer pong table and connecting procedure will be analyzed in detail in the analysis of FIGS. 7 and 8 .
[0032] The front side 41 of the male assembly 15 is also constructed out of a solid piece of rigid siding, but is also equipped with two protruding L-shaped male connector pieces 42 (hereinafter referred to as male connector pieces). The male connector pieces 42 will connect with female connector pieces 44 and 32 to form any of larger tables previously mentioned. The connecting procedure will be described in detail in FIG. 7 .
[0033] Located on the top surface and proceeding completely through each of the assemblies 15 and 20 is a through aperture 22 , with a diameter of approximately six inches, which is large enough to allow a beanbag to pass completely there through when the assemblies 15 and 20 are being used for game play. Two cover caps 21 will most likely be included with the purchase of the invention 10 that will fit flush within and completely cover the apertures 22 creating a completely solid and unitary top surface. In addition to these caps 21 there may also be a plethora of other optional and/or additional attachments that could be manufactured to fit within the apertures 22 , such as ice buckets, condiment trays, trashcans, etc. when the assemblies 15 and 20 are being used as tables.
[0034] FIG. 2 is an aerial view of the underside of the female assembly 20 with the through aperture 20 located towards the top of the assembly 20 and all of its legs 54 , 56 , and 58 folded completely flat (for an identical view depicting the male assembly 15 , refer to FIG. 3 ). Both sides 30 and 31 , along with the rear 40 and front 43 are raised approximately two inches from the bottom surface of the assembly 20 and create a storage space for all of the legs 54 , 56 , and 58 whenever any of those legs are not in use. As illustrated in FIG. 2 , all of the invention's table and game legs can fold completely within the two inch raised border created by the four sides of each unit and cannot be seen when viewed from the side. As shown in FIG. 2 , both connecting mechanisms 44 and 32 are located in midway down their respective sides 43 and 31 , approximately one inch down. FIG. 2 depicts assembly 20 in its most compact and portable configuration and is how the invention will be configured when in travel mode.
[0035] Both assemblies 15 and 20 have been constructed to withstand harsh treatment and maintain its structural integrity without breaking down or falling apart when used as a table, beer pong table, or cornhole. FIG. 2 illustrates this fact by showing the two strong metal rails 52 that run along side and which are securely fastened to the two longer sides 30 and 31 of the assembly 20 . These structural rails 52 also provide a stationary base for the table leg mechanism's 56 brackets 51 to anchor onto. Another important aspect of the structural rails 52 is that they serve as connecting point for the metal tubing 53 that allows all of the table leg mechanisms 54 and 56 to rotate on and extend down to create a table. Another tube with a slightly wider circumference 57 is fitted around the rear tube 53 that is closer to the through aperture 22 . This wider tube 57 is attached to the gaming leg mechanism 58 and allows these legs to move independently and without disturbing the table leg mechanism 56 . In other words, the wide tube 57 allows the table leg mechanism 56 to extend while the gaming leg mechanism 58 remains folded within the assembly 20 and allows the gaming leg mechanism 58 to extend, while the table leg mechanism 56 remains recessed within the assembly 20 . While the two metal tubes 53 allow the leg mechanism 54 , 56 , and 58 to rotate and fold out of the assembly 20 , the four brackets 51 dictate how far the legs will extend and lock them into the predetermined destination. In this case, the predetermined destination is perpendicular to the assembly's 20 surface or 90 degrees to create a table, or gaming assembly. The exact mechanics of these brackets will be described in further detail in FIG. 5 Another important aspect of the assembly 20 are the three vertical columns 59 A, 59 B, and 59 C that run the length of the assembly 20 . These columns 59 serve three distinct functions and will most likely be composed of the same material as the surface and sides of the invention 10 , but may ultimately be composed of any kind of rigid material, such as aluminum, steel, etc. First, they will reinforce and further stabilize the invention 10 , making each assembly 15 and 20 more reliable when used as a table or as a cornhole game. Secondly, the two outer columns 59 A and 59 C, act as immobile supports for the brackets 51 , which are also connected to leg mechanisms 54 and 58 , to anchor themselves to. Finally and most importantly, the columns will provide a way to secure the leg mechanisms 54 , 56 , and 58 underneath the assemblies 15 and 20 when they are not in use. To accomplish this task, five cut out indentions 60 will be located on the three columns, that are just wide enough to allow the leg mechanisms' stability bars 55 to snap and stay in a folded position. As shown in FIG. 2 , the two outer columns 59 A and 59 C will each only need one cut out indention 60 to secure the outer table leg mechanism 56 into place. The center column 59 B however, will need to have three cut out indentions 60 , one for each leg mechanism 54 , 56 , and 58 .
[0036] FIG. 3 is taken from the exact same aerial view as FIG. 2 and is only included for two reasons. First, to show what both assemblies would look like side by side with their top surfaces facedown. And secondly, to show what both of the assemblies 15 and 20 would look like in travel mode with all leg mechanisms, table 54 , 56 and game 58 , folded completely flat within the recesses of their respective assemblies. In this compact state, the assemblies will be able to be stacked one atop the other and be transported and stored.
[0037] FIGS. 4A and 4B are sectional and perspective views of the intersection of the right 30 and rear 40 side of the male assembly 15 and depict the rear table leg mechanism 56 fully extended and locked into position by a bracket 51 . FIG. 4A is a perspective depiction of what assembly 15 would look like if unfolded into a table. The metal tube 53 allows the rear table leg mechanism 56 to rotate down from a folded position within the table into the extended position depicted in FIG. 4A The rear leg mechanism is a single unitary part and includes two legs which are connected together by a support bar 55 , allowing both legs to move in unison. So even while FIG. 4A and 4B may be illustrated to show only one of the two table legs, the second leg is hidden behind the leg closest to the viewer. As mentioned previously, the brackets 51 are secured to both the table leg and the right side 30 of the assembly 15 . However, the middle of each bracket 51 is not connected to anything stationary, and is able to swivel freely about a hinge when not in its locked position, which is described more fully in FIG. 5 .
[0038] FIG. 4B is an alternate view of FIG. 4A and shows the rear table leg mechanism 56 beginning to fold back into the recess created by the sides 40 and 30 of the assembly 15 . As in FIG. 4A , the fixed metal tubing 53 allows the leg mechanism 56 to rotate upward into the assembly 15 , as shown by the arrow. FIG. 4B shows bracket 51 broken out of its locking position and following/swiveling with the upward movement of the table leg mechanism 56 . Part 55 is still connecting the two rear legs 56 forcing the legs to move as one. While only the rear table leg mechanism 56 is depicted in FIG. 4A and 4B , it should be understood that the other two leg mechanisms 54 and 58 depicted in FIG. 2 and FIG. 3 , utilize the same method of folding and extension as the rear leg mechanism 56 depicted in FIG. 4A and FIG. 4B .
[0039] FIG. 5 is a sectional and aerial view of the top right corner, as created by the intersection of the rear 40 and right 31 side, of the assembly 20 as circled in FIG. 2 . As depicted in FIG. 2 , the brackets 51 are folded completely in half on top of itself, with one end B 4 securely fasted to its respective leg mechanism 56 or 58 and the other end B 5 fastened to an immobile part 52 or 59 A of the assembly 20 . The middle of each bracket is able to rotate on a hinge B 3 , which allows the bracket 51 to extend with its respective leg mechanism 56 or 58 as the leg mechanism rotates on its respective metal tubing 53 or 57 and extends out of the assembly. The most important function of the brackets 51 is that they restrict the movement of the leg mechanisms 54 , 56 , and 58 and lock them into place at a 90° angle in relation to the assembly 20 . To achieve this, each bracket 51 is fitted with two interlocking pieces B 1 and B 2 that lock into one another and don't allow the bracket 51 to extend or the leg mechanisms to rotate any further. The fully extended and locked bracket 51 is shown clearly in FIG. 4A . FIG. 4B shows the bracket 51 in its transition phase. There will be six brackets 5 Ion each assembly, two per leg mechanism 54 , 56 , and 58 as shown on FIGS. 2 and 3 .
[0040] FIG. 6A and 6B are perspective views of one of the assemblies 15 or 20 standing as an independent table. As shown, both table leg mechanisms 54 and 56 , connected together by their support bars 55 , have rotated down on their respective metal tubing 53 and are completely extended and locked into place by the brackets 51 . FIG. 6A is a view of the right side 30 of the assembly and shows that the gaming leg mechanism 58 is still locked and recessed within the assembly and has not rotated on its metal tubing 57 to extend down. FIG. 6B is an alternate view of FIG. 6A showing a perspective view of the rear 40 of the assembly, as it would appear if standing as an independent table.
[0041] FIG. 7A , 7 B, and 7 C together are a magnified and sectional aerial view of invention 10 , demonstrating how the male assembly 15 would most likely lock into place with the female assembly 20 to create one of the two tables that will be depicted in FIG. 8 and FIG. 9 . Specifically, FIGS. 7A-C depict how the male assembly's 15 protruding connector piece 42 will be inserted and locked within the female connector piece 44 of assembly 20 . It must be noted that FIGS. 7A-C are labeled to depict the assemblies 15 and 20 connecting end-to-end 41 -to- 43 as shown in FIG. 8 , but the identical motion would be used to connect the assemblies perpendicular to one another to form an L-shaped table as shown in FIG. 9 . Also, despite the fact that FIGS. 1-3 show there being two connecting mechanisms on each side, there may ultimately be three or free connecting mechanisms on the final product depending on the materials used in the construction of the invention 10 . The first step to connect the tables is to line up the male connector piece 42 with the opening of the female connector piece 44 as shown in FIG. 7A . The male connector piece 42 will most likely be made of some sort of metal or rigid plastic. The right side 30 of assembly 15 must be slightly lower than the left side 30 of assembly 20 , in order for the invention 10 to line up in a straight line when the assemblies 15 and 20 are locked into place as in FIG. 7C . The distance of this misalignment will likely not be more than a couple inches. The next step in the process is to push the two assemblies 15 and 20 together, so that the male connector piece 42 is completely within the female connector piece 44 as shown in FIG. 7B . FIG. 7C shows the two assemblies 15 and 20 locked together. The male connector piece 43 has now been slide upward into the notched out hole within the female connector piece 44 . With one of these connecting mechanisms 42 and 44 on opposite ends of each side of the assemblies 15 and 20 , the invention should be solid and should not be able to be pulled apart. FIG. 7A-C is included in this writing to show the examiner one possible way the invention 10 could be connected, however there are many different alternatives that may ultimately be used to connect the assemblies 15 and 20 . FIG. 7A-C should not be understood to be the only or best way the assemblies 15 and 20 can be connected he inventors reserve the right to change the locking mechanism in the final product, as long as the final locking mechanism operates in roughly the same manner.
[0042] FIG. 8A is a perspective side view 30 of the invention 10 connected end-to-end 41 -to- 43 as referenced in FIG. 1 , thus creating an elongated dinning table, or alternatively, a beer pong table. The approximate length of the elongated table is eighty-eight inches, with an approximate width of twenty-four inches. As shown in FIG. 8A , all four of the invention's 10 table leg mechanisms 54 and 56 are extended and locked into position by their respective brackets 51 . The male assembly's 15 protruding connector pieces 42 are completely engulfed and locked into the female assembly's 20 receiving connector pieces 44 . FIG. 8A illustrates what the invention 10 would look like if the cover caps 21 were inserted flush within the invention's through apertures 22 . However, as mentioned earlier, there will mostly likely be other attachments that will be manufactured to fit within the invention's 10 two through apertures 22 . The cover caps 21 shouldn't be understood to be the only possible attachments that could be inserted into the invention's through apertures 21 .
[0043] FIG. 8B is an alternate and aerial view of FIG. 8A . FIG. 8B shows more clearly than FIG. 8A , how the two assemblies 15 and 20 are connected end-to-end 41 -to- 43 and locked by their respective connecting pieces 42 and 44 . The cover caps 21 depicted in FIG. 8A have been removed in FIG. 8B leaving the invention's through apertures 22 exposed. The female connector pieces 32 on the topside 31 of the female assembly 20 are not in use and are located within the middle of the topside 31 of assembly 20 . While the female connector pieces 32 appear to be located on the top playing/dinning surface of assembly 20 in FIG. 8B , they are not positioned on the surface, but on the side 32 of the table and are only shown in FIG. 8B to assist the examiner.
[0044] FIG. 9A is a perspective view of the side 31 of assembly 20 and the rear 40 of assembly 15 , as they would appear if connected perpendicular to each other, forming an L-shaped serving table. Each assembly's through apertures 22 would be located on opposite sides of the table from one another. All four of the invention's table leg mechanisms 56 and 54 , are completely extended and locked into place by eight brackets 51 . Not shown in FIG. 9A , are the extended front leg mechanism 54 and its support bar 55 of one of the assemblies 20 . This leg mechanism 54 was omitted intentionally, so as not to make FIG. 9A too cluttered and confusing for the examiner. However, it should be understood that this leg mechanism 54 and its support bar 55 would be fully extended and locked into place by two brackets 51 .
[0045] FIG. 9B is an alternate, aerial view of FIG. 9A and shows more clearly how the two assemblies 15 and 20 have been connected and also the positioning of the two through apertures 22 on the surface of the table. While the through apertures 22 are not covered by the cover caps 21 shown in FIG. 1 and FIG. 8A , or any other attachment, it should not be understood that the apertures 22 could not be fitted with the cover caps 21 or any other attachment that may be manufactured. As shown in FIG. 9B , the male connector pieces 42 situated on the front side 41 of the male assembly 15 are completely engulfed and locked into the female connector piece 32 located on the left side 31 of the female assembly 20 . The female connector piece 44 not in use is situated on the front 43 of assembly 20 , about one inch from the surface of the table. While it may appear that these idle connector pieces 44 are located on the surface of assembly 20 , they are illustrated to ease the understanding of the examiner and should not be construed to be two indentions on the surface of the table.
[0046] FIG. 10A is a semi-aerial view of the male assembly 15 when serving as a cornhole game. FIG. 10A is taken from the rear 40 of the male assembly looking down the slope towards the front 43 of the assembly 15 . While FIGS. 10A and 10B portray only one of the assemblies 15 , it should be understood that the other assembly 20 would look and operate in the exact same way. FIG. 10A illustrates what the game leg mechanism 58 would look like after it has rotated about its metal tubing 57 , as shown in FIG. 2 , and been locked into place by its two brackets 51 perpendicular to the gaming assembly 15 . The makeup and operation of the brackets 51 are identical to those illustrated in FIGS. 4A , 4 B, and 5 . Similarly, the extension and locking process of the game leg mechanism 58 are almost identical to that of the table leg mechanisms 54 and 56 , as described previously in FIGS. 4A , 4 B, and 5 . In this view, the only leg mechanism extended and in use from the underside of the assembly 15 is the game leg mechanism 58 . When the game leg mechanism 58 is in use, the front side 41 of the assembly 15 is in direct contact with the ground. The function of 58 is to lift the rear of the assemble twelve inches off the ground to allow the target assembly to sit at approximately 45 degrees.
[0047] Since the only leg mechanism extended from the underside of the assembly 15 is the game leg mechanism 58 , when placed on a horizontal surface, the front side 41 of the assembly 15 is in direct contact with the ground because the game leg mechanism 58 lifts the rear of the assembly 15 approximately twelve inches off the ground and creating an inclined cornhole playing surface, with the through aperture 22 located towards the top of the incline for beanbags to be thrown at and through. The degree of the incline is approximately 45°.
[0048] FIG. 10B is an alternate and perspective view of FIG. 10A , depicting the left side 30 of the male assembly 15 , as it would appear in cornhole game mode. FIG. 10B is identical to FIG. 10A in every way and is included to better illustrate one of the brackets 51 in its full and locked position and also to show the incline and slope of the assembly 15 in cornhole game mode, which like FIG. 10A is approximately 45°.
|
The Play-ble Recreational System is composed of two separate assemblies, each of which includes a through-aperture, dimensioned to allow a beanbag to pass entirely through it, which can be sealed by a detachable cover cap. The invention will be constructed so that the assemblies can serve multiple functions. When the assemblies are separate and distinct, they will primarily be used to play the popular multiplayer game, commonly referred to as cornhole or beanbag toss. However, in addition to this, the underside of each assembly is equipped with collapsible table and game legs, which allows each assembly to become an independent freestanding table. The assemblies also include mechanisms on their front and/or side surfaces that allow the assemblies to be connected together in one of two ways: either perpendicularly to form an L-shaped buffet/serving table, or end-to-end to create a long dinning/serving table that can also be used to play the popular recreational game referred to commonly as beer pong.
| 0
|
This is a continuation, of application Ser. No. 432,451 filed Jan. 11, 1974 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to whippers, and more particularly the hand crank variety which are combined with a bowl or pitcher, and having a plurality of beaters each with a plurality of tines which are orbitally moved throughout the bowl while being rotated therein. Relevant patent literature appears in Class 259, subclasses 29, 35, 116, and 118 and elsewhere and the patent and commercial literature directed to whippers, agitators, and the like.
2. Description of the Prior Art
The prior patent literature is representatively disclosed in French Pat. No. 1020683 and Swiss Pat. No. 243069. As to the United States patent literature, patents issued as early as U.S. Pat. Nos. 374,706 and 1,192,426 disclose various forms of combined orbital and rotary beating. In principle, the prior art illustrates a plurality of members which are rotated by means of clusters of gears working against a single ring gear, whether the ring gear relationship be internal or external. In addition, a generally orbital motion is defined by clusters of the rotary members.
Upon tracing the gear trains, it becomes apparent that a significant amount of inherent mechanical friction exists, and thus effort is dissipated through the relationship of the gears. It follows, therefore, that more effort is required to actuate the beaters. Furthermore, many if not most of the examples of the prior art disclose beaters which are awkward to wash, and are of such a construction that inherently they cannot be molded of plastic.
A recent development with regard to plastic beaters may be found in U.S. Pat. Nos. 3,215,410 and 3,328,005 but as will be observed, the mechanism for securing the beaters as represented in these patents is essentially a cost provoking metal shaft. Just the mating of the metal to the plastic tines involves a cost increment, as well as a weak point to detract the overall efficiency and economy of the beaters as shown in the subject patents.
Finally, there appears to have been little effort or thought directed in connection with the beaters exemplified by the foregoing patents to a unit which can be quickly disassembled, and easily washed, and reassembled for further drying even while stored in a kitchen cabinet. Also, the hand manipulated orbital type beaters of the prior art do not possess a combination of high speed and total penetration of the beaters within the bowl to significantly reduce the effort required as well as the time to conclude the beating or whipping operation.
SUMMARY
The invention is directed to a whipper having a plurality of orbitally and rotated beaters. A plurality of beaters are employed, each of which has an open ended lower portion and a plurality of tines. With a three-beater and thus three-legged construction, a free standing of the gear housing assembly and beater permits easy self draining. The gear housing is a dome-like member which is secured by means of a bayonet-like fastener to the gear assembly, the latter being secured by means of interconnected beater plates and ring gear plates. The housing is lockingly secured in relationship with the gear assembly by means of the penetration of the crank through an opening in the housing. The beaters are removably secured to the gear assembly by means of a preferably plastic molded socket-spline as shaft relationship, the splines on the beater plate being integral with the beater gears which, in turn, match with the ring gear. Gear ratios are selected between the bevel gear on the drive shaft, and the bevel gear on the beater plate to provide a two-to-one ratio, the ratio between the beater gears and the ring gear being five to one. These ratios result in two orbits of the beater plate for each rotation of the crank, and ten rotations of the beaters for each rotation of the crank. A bowl is provided of generally cylindrical cross section which may desirably be graduated to indicate its contents. The pouring spout of the bowl coacts with a spout key on the gear housing to secure the same atop the bowl; and similarly an egg separator coacts with the upper portion of the bowl and is coordinated in position by means of the pouring spout. An ejector, in the form of an elongated member penetrating through the hollow drive shaft, may be thumb pressed from a position opposite the crank handle mount of forcibly eject the crank handle from its coacting relationship with the drive shaft to thereafter easily remove the housing for disassembly, and cleaning of the housing, frank, gear assembly, and beaters as they may be separated from each other. The beaters are formed with a knife edge on both sides and a thickened center section. The knife edge promotes ease of penetration of the material being mixed, and the thickened center section directs the material being whipped centrally into the beaten zone interiorly of the tines. The lower extremeties of the beater tines are curved centrally with a continuation of the thickened center section in order to assist in stripping material off the bottom of the bowl, and also to assist draining when the tines are withdrawn from the material being beaten. The distance between the substantially vertical side walls of the bowl and the beater tines is proportioned for a relationship as close as possible, and yet one which will accommodate the centrifugal action separating the tines under heavy use without the tines contacting the bowl walls or base. The base of the bowl is radiused at its lower edge in a configuration approximating the curve of the lower portion of the tines.
In view of the foregoing, it is a primary object of the present invention to provide a whipper which minimizes the time required for whipping various mixers as compared to the known hand operated or even hand-held electric powered existing beaters. A related object of the present invention is to provide a whipper which is driven through an efficient gear train and with a highly efficient beater to permit manual operation by a person of modest strength. Still another related object of the present invention is to provide a whipper in which the crank handle operates in a natural full swing relationship eliminating the tiring wrist action of other hand operated beaters. By way of example, the hand operation of the subject whipper will whip cream in approximately forty seconds. Egg whites, on the other hand, can be whipped to the point that the bowl may be inverted without dripping in approximately fifteen seconds.
A further desirable object of the present invention is to provide a whipper with a plurality of separate beaters so that the unit remains self-standing for draining, and batter clinging to the tines will self-strip by gravity between operations.
Yet another important object of the present invention is to provide a whipper which can be self washed by adding a detergent and a small amount of water interiorly of the mixing bowl, and then agitating the same way as when whipping, the agitation simulating that of mechanical washing equipment.
Still another significant object of the present invention is directed to an orbital-type beater in which the parts may be readily disassembled for cleaning manually, and without the interaction of metal parts such as springs, detents, latches, and the like. This objective is achieved by providing a bayonet-type fastener between the housing and the gear assembly which is thereafter secured in place by means of the crank engaging the drive shaft through a matching port in the housing, thus securing the same against dislodgment.
Still another object of the present invention looks to the provision of beaters which are snap fittingly engaged to the beater gears, and which can be molded from plastic which provides the two-fold advantage of minimized corrosion, and economy of manufacture.
Still another object of the present invention is to provide a whipper, the parts of which can be quickly disassembled for washing in a dishwasher, or otherwise cleansing, and yet may be reassembled and positioned in the bowl for further use with any drippage or drainage passing into the bowl and thus rendering the same ready for restorage in a cupboard without dripping or affecting other items in the cupboard.
DESCRIPTION OF ILLUSTRATIVE DRAWINGS
Further objects and advantages of the present invention will become apparent as the following description of an illustrative embodiment proceeds, taken in conjuction with the accompanying drawings in which:
FIG. 1 is a partially cross-section view of the subject whipper broken in certain portions to illustrate various of the related coacting members.
FIG. 2 is an exploded partially diagrammatic view illustrating the disassembled relationship between various of the elements.
FIG. 3 is a further exploded view of the gear drive train, partially broken, and partially in section to illustrate the relationship of the parts.
FIG. 4 is a front elevation of the housing for the gear assembly.
FIG. 5 is a bottom view of the gear housing shown in FIG. 4 in the same scale as shown in FIG. 4.
FIG. 6 is a front elevation of the ring gear plate showing a bearing in disassembled relationship.
FIG. 7 is a bottom view of the ring gear plate as shown in FIG. 6 and in the same scale as FIG. 6.
FIG. 8 is an end view, partially sectioned, of the ring gear plate in the same scale as FIGS. 6 and 7 but taken from the right end of FIG. 6.
FIG. 9 is an end view of the beater plate, partially sectioned and partially exploded to show the disassembled relationship between the bearing and the ring gear plate.
FIG. 10 is a bottom view of the beater plate in the same scale as shown in FIG. 9.
FIG. 11 is a front elevation of the beater plate bevel gear and the stub shaft extending therefrom.
FIG. 12 is a bottom view in slightly enlarged scale of the bevel gear of FIG. 11.
FIG. 13 is a front elevation showing the unitary beater gear and beater spline.
FIG. 14 is a front elevation of an exemplary beater showing the socket and related snap head connector partially in phantom lines.
FIG. 15 is a top view of the beater shown in FIG. 14 in the same scale as shown in FIG. 14.
FIG. 16 is a transverse sectional view looking downwardly along section line 15 - 15 of FIG. 14 of the beater.
FIG. 17 is an end view of an egg separator used in combination with the bowl of the subject whipper.
FIG. 18 is a plan view of the egg separator in the same scale as FIG. 17.
FIG. 19 is a front elevation of the egg separator of FIGS. 17 and 18 in partial section, partial phantom lines, and showing in broken lines the coacting relationship between the egg separator and the whipper bowl.
DESCRIPTION OF PREFERRED EMBODIMENT
The subject whipper is illustrated particularly in FIG. 2 of the accompanying drawings where it will be seen that the whipper 10, in front elevation, is provided with a handle 12 at one side for lifting the bowl 11, and is provided with a crank 15 at the other side for rotating the beaters 20. As illustrated, three beaters 20 are employed in the assembly, and are spaced on equilateral triangular centers, as disclosed in FIG. 10. The invention may also be practiced, however, with two beaters, or four beaters, the number three being selected as a desirable selection of a plurality of beaters.
The housing 50 of the gear housing assembly 25 fits on top of the bowl 11 as shown in phantom lines in FIG. 2. Particularly to be noted is the coordinated relationship between the spout 14 on the bowl 11, and its interlocking relationship with the spout key 51 of the gear assembly housing 50. An upper stepped ring 56 and lower stepped ring 58 are provided in the housing 50 for the gear assembly 25. Thus, as shown particularly in the left-hand portion of FIG. 2, when the user operates the unit, either the left or the right hand interchangeably may be placed on top of the housing 50, the fingers as well as the palm of the hand engage the stepped rings 56, 58, and then the opposite hand is employed to rotate the crank 15. After the contents have been adequately whipped or beaten, the gear assembly 25 as well as the crank 15 are removed with the attached beaters 20, and the same may be positioned in a free standing configuration generally as shown in the right-hand portion of FIG. 2 in reduced scale. This configuration permits the tines of the beaters to drain onto a flat surface as shown. The bowl 11 may then be grasped by the handle 12 and the contents either poured out with the assistance of the spout 14, or removed by a spoon or spatula.
In greater assembled detail, referring to FIG. 1, it will be seen that the crank 15 employs a grip 16, and a socket 19 at one end of the crank arm 18. The crank 15 is made substantially in accordance with Applicant's assignee's U.S. Pat. No. 3,406,590. The socket 19 of the crank 15 has a female hexagonal relief portion in its interior, and coactingly engages a crank hex 75 at the one end of the drive shaft 35. The drive shaft 35, pursuant to details to be described below, is journaled in a ring gear plate 26 which is housed within the housing 50 and is an integral part of the gear housing assembly 25. The drive shaft 35 rotates a drive shaft bevel gear 40 which, in turn, coacts with a beater plate bevel gear 41 which rotates the beater plate 28. The annular area defined between the beater plate 28 and the ring gear plate 26 provides space for a plurality of beater gears 24 which are journaled in the beater plate 28 to coact with the internal ring gear 45 of the beater plate 28. Each of the beaters 20 is provided with a plurality of beater tines 21 which, as shown in FIG. 1, extend downwardly from the beater socket 22 with a substantially continuous center thickened cross section terminating in opposed knife edges and having a flat outer surface. A curved lower end portion leaves the bottom portion of the beater open, as specifically shown in FIG. 16, a cross-sectional view looking downwardly from section 15--15 of FIG. 14 which shows the beaters 20 in greater detail and having an isosceles trapezoidal cross section. The lower ends of the tines 21 have a modestly curved end (less than 45%) with a continuation of the thickened cross-section and knife edges. This permits an upward thrust to scour the bottom of the bowl 11 and yet allows the material to flow off the ends when the beaters 20 are removed from one bowl.
Another feature of the invention shown in broad outline in FIG. 1 is the provision of an ejector 30 which has an ejector shaft 31 terminating in an ejector button 32, the latter extending outside of the housing 50. The opposite end of the ejector shaft 31 abuts against one snap head 81 (see FIG. 3) of the crank socket 19, and when the button 32 is pressed, it presses against the snap head 81 and pops the crank 15 off of its otherwise secured interfitting hexagonal relationship 75, 80. In order to prevent the ejector button 32 from impeding the disassembly of the housing 50 from the gear assembly 25, the ejector 30 is provided with an ejector yoke 34 (as shown in FIG. 1), the lower extremity of the yoke being slightly yieldable to pass over the ejector stop 39, and thus, in the eject position, and button 32 is held inside the housing 50. Additionally, a snap lock 37 assists in assembly and prevents the ejector from falling out when the gear assembly is disassembled and washed. When the crank 15 is reinserted into its hex relationship 75, 80 with the drive shaft 35, the ejector shaft 31 is then pushed in the opposite direction and the ejector button 32 penetrates the ejector button hole 29 in position for again ejecting the crank 15. The yoke 34 then nests between the snap lock 37 and the ejector stop 39.
Additional details of the gear housing assembly 25 appear in the exploded view of FIG. 3 of the drawings. There it will be seen that the ring gear plate 26 is secured in its spaced relationship to the beater plate 28 by means of inserting the bevel gear pin 85 into the interior portion of the beater plate bevel gear 41, the coacting splined relationship being defined by the spline 88 which is interior of the gear socket 86 of the beater plate 28, and the spline teeth 89 on the stub shaft 42 of the lower portion of the bevel gear 41. In assembly, this attachment of the bevel gear pin 85 to the bevel gear 41 does not take place until the three beater gears 24 are positioned within the beater gear bearings 65 in the beater plate 28, generally as shown as to one such beater gear 24 at the left-hand portion of the beater plate 28 in FIG. 3. The beater gear 24, as noted in its orientation, is positioned to coact with the ring gear 45 of the ring gear plate 26. Thus when the crank 15 is rotated it rotates the drive shaft 35 which in turn couples the drive shaft bevel gear 40 with the beater plate bevel gear 41. The beater plate bevel gear 41 rotates the beater plate 28, and thus causes the beaters 20 to orbit within the bowl 11, and also to rotate as the beater gear 24 continues to travel in the circle around the ring gear 45.
The interlocking relationship between the beater 20 and the beater spline 60 beneath the beater gear 24 is shown at the lower left-hand portion of FIG. 3. There it will be seen that the beater 20 has a beater socket 22 at its upper portion. The beater socket 22 contains interiorly thereof an upward projection terminating in a snap head 70. The snap head 70 is proportioned to snap fittingly engage the collar 61 which is inside the beater spline 60. Thereafter the socket spline 71 coacts with the projections on the beater spline 60, and the elements are thus interrelated. Also to be noted is the sleeve 72 extending at the upper portion of the beater socket 22 which slidingly coacts with the guide shirt 68 extending downwardly from an integral with the beater plate 28 to further insure the positional orientation of the beater 20 while it rotates and orbits within the bowl 11.
One of the stated objects of the invention of the subject whipper 10 is to provide for the disassembly of the parts, including the housing 50 being removed from the gear housing assembly 25 for cleaning, the crank 15 being removed further for cleaning, and the beaters 20 being removable from the gear housing assembly 25. These methods of removal, with the exception of the disengagement of the housing 50 from the gear housing assembly 25 have been shown and described above. By referring to FIGS. 4 and 5, it will be seen that the gear housing 50, and its underneath portion, is provided with opposed interlock keys 49 which are a segmented portion. The keys, in turn, are assisted in an adjacent area by the locator stops 64 of the ring gear plate 26 which terminate the rotational bayonettype connection between the housing 50 and the locking portion defined coactingly between the ring gear plate and beater plate 26,28.
Turning now to FIG. 7, it will be seen that the ring gear plate 26 is provided with an interlock key segment 48 cut out of the interlock ring 46 and proportioned to coact with the interlock key 49 of the housing 50. The relative positions of the interlock key 49 and the interlock key segment 48 are such that when the locator stop 64 is encountered, the crank hex 75 will be positioned directly opposite the crank hex hole 52 in the housing 50, and the ejector button 32 will be positioned directly opposite the ejector button hole 29 in the housing 50. Thus when the interlock key 49 and the interlock key segment 48 have been properly aligned and brought against the interlock locating stop 64, the elements are in position for the hex socket 80 of the crank 15 to be thrust over the crank hex 75 of the drive shaft 35, the "ready position" being shown at the upper right-hand corner of FIG. 3. As the crank hex 80 is inserted over the drive shaft hex 75, the interior snap head 81 of the crank 15 advances in order to engage the interior hex collar 76 of the drive shaft hex 75. At the same time, the end of the snap head 81 engages the right-hand end of the ejector shaft 31 (as shown in FIG. 3) and pushes the ejector 30 to the left so that the ejector button 32 passes through the ejector button hole 29 in the housing 50, while the lower portion of the ejector yoke 34 pops over the ejector stop 39 which is in the upper portion of the ring gear plate 26.
The specific construction of the ring gear plate 26 is shown in FIGS. 6 through 8. There it will be seen that the ring gear plate 26 terminates at its base in an outer peripheral interlock ring 46 as described. The ring gear 45 is molded as an internal ring gear in the underneath portion of the ring gear plate 26. Extending upwardly from the ring gear plate 26 are opposed crank end bearing support 36 and ejector end bearing support 38. Each of these have an interior molded through bore to press fittingly receive the crank end bearing 82 and the gear end bearing 84. The drive shaft 35 is passed through the bearings 82, 84 and secured in place by means of the coacting relationship between the bevel gears 40, 41. Extending downwardly from the ring gear plate 26 are a plurality of locator stops 64, particularly as shown in FIG. 8, which coact with the interlock key segment 48 and interlock key 49 to align the opposed holes in the housing 50 prior to the reassembly of the crank 15 onto the gear housing assembly 25 as described above. Also to be noticed, particularly in FIG. 7, is the provision of a plurality of drain holes 94 in the ring gear plate 26 for purposes of permitting contained water, typically deposited during a dishwashing cleaning, to drain from the gear housing assembly 25.
The details of construction of the beater plate 28 are shown particularly in FIGS. 9 and 10. There it will be seen that the beater plate 28 terminates in the upwardly positioned gear socket 86, with the gear pin 85 extending upwardly from the center as described above. Provision is made with bearing holes 92 in the beater plate 28 for the press fitting insertion of the beater gear bearing 65. The beater gear bearing 65, in turn, receives the beater spline 60 of the beater gear 24, as shown in FIG. 13. The shoulder 62 immediately beneath the beater gear 24 rides atop the flange portion 66 at the upper end of the beater gear bearing 65. The beater gear spline 60 extends beneath the guide shirt 68 of the beater gear plate 28. Also to be noted is the provision of a splash ring 95 which extends around the entire periphery of the beater plate 28, and is intended to fit within the bowl 11 in close spaced proximity to its upper interior edge portion thereby coacting with the splash rim 55 of the housing 50 to prevent the contents of the bowl 11 from escaping around its upper portion while the beating action takes place. The upper edge of the splash ring 95 also coacts with seating ring 59 of the housing during assembly. In addition, the bowl shirt 54 extends downwardly from the housing 50, and penetrates the interior portion of the bowl 11 particularly as shown in FIG. 1.
Interior snap ring attachments are contemplated at various points. For example, a snap ring 90 is provided to secure the upper portion of the bevel gear pin 85 atop the bevel gear 41 as shown in FIG. 3. Additionally, a further snap ring 79 is positioned against the shoulder 78 of the drive shaft 35 in order to lock the drive shaft 35 in position interiorly of the bearings 82, 84 provided for the drive shaft.
In order to secure the unit against dislodgment while hand held atop a working surface, such as Formica table, a rim 96 (see FIG. 1) is provided around the periphery of the base of the beater 11. This rim is molded with an interior rib construction 98 which in turn coacts with the tongue and groove circular construction 99 molded at the lower portion of the bowl 11 to secure the resilient ring 96 underneath the bowl 11. Thus, when the operator positions the hand on top of the housing 50, and rotates the crank 15 by grasping the crank grip 16, the unit is secured in position and tipping, slippage, or other dislodgment is avoided by means of the pressure relationship between the hand atop the housing 50, and the rim base ring 96 on the surface on which it is being worked.
The ratios between various gears figure significantly in the efficiency of operation of the whipper 10. Ideally in the commercial unit, the drive shaft bevel gear 40 has 24 teeth, and the beater plate bevel gear 41 has 12 teeth thus resulting in a two-to-one relationship between the drive shaft bevel 40 and the beater bevel 41. With this relationship, a single turn of crank 15, results in two orbits of the beater plate 28 and the associated beaters 20. Further, each of the beater gears 24 has ten teeth, whereas the internal ring gear 45 has 50 teeth. Therefore for each rotation of the beater plate 28, there are five rotations of the beaters 20. Stated more specifically in functional language, for one turn of the crank 15 there are two orbits of the beaters 20, and ten turns of the beaters 20. Because there is only a single beater gear coordinated with the internal ring gear at three locations, internal friction is significantly reduced, and yet the four tines 21 of the beaters 20 are rapidly passed through the contents of the bowl 11 and, aided by the isosceles triangular cross section of the tines 21, are quickly aerated without flogging the contents, or degrading the contents (such as whip cream from cream to butter) but rather aerating and fluffing the same quickly. In addition, the gear ratios are coordinated with the beaters 20, and the length of the handle 15, so that the average homemaker finds little major resistance to 15 to 20 seconds of operation which is normally all that is required to fluff the whites of two eggs.
A further desirable feature of the whipper 10 is its ability to accommodate a double egg separator 110 of the character shown in FIGS. 17 through 19 of the accompanying drawings, and more particularly as specifically set forth in co-pending patent application Ser. No. 361,430 filed May 18, 1973, entitled "Double Egg Separator". For purposes of detailed description, the aforesaid patent application description is incorporated herein by reference. For purposes of review, however, it will be seen that the double eggs separator 110 includes a pair of opposed support ears 111 connected, as shown in FIG. 18, by a support rim 112 having a depending support skirt 113. Drain walls 114 depend from the support rim 112 and a plurality of spiders 128 support a pair of yolk cups 115 in the central portion of the drain walls 114, separated by drain slots 116. Conveniently, a hanging hole 119 is provided in one of the support ears 111 for securing the same on a hook or nail normally mounted on the wall. Centrally of the egg separator 110 is a cracker 120 having a flanking pair of cracker walls 121 and terminating at its upper edge in a cracker edge 122. A stand ring 125 is provided around the entire under-surface of the double egg separator 110, for the two-fold purpose of positioning the same on a flat surface, or alternatively for nesting the same interiorly of the bowl 11 of the whipper 10. In addition, the underneath portion of the support ears 111 in combination with the support rim 112 and support shirt 113 overlap and receive in oriented nested relationship the spout 14 of the bowl 11 of the whipper 10.
Therefore, when preparing an omelet, for example, two eggs may be separated in the double egg separator 110 with the yolks nesting in the yolk cups 115 while the balance of the egg white drains through the drain slots 116 and the cup drain 118. Thereafter the double egg separator 110 may be removed from the bowl 11, the whipper 10 activated to froth the egg whites while the double egg separator 110 sits on a flat surface, and the egg yolks thereafter dropped into the bowl 11, and mixed by quickly agitating again with the whipper 10. The result is a light fluffy omelet mix which can be thereafter spooned or folded onto a skillet or omelet maker producing a delicious omelet serving two to four people, depending upon their appetites.
Although the dimensions are not critical to the invention, certain proportions are highly desirable in usage. For example, in the commercial embodiment the diameter of the bowl 11 is nominally five inches, as is its depth. This permits the height of approximately 3 1/2 inches to be graduated from 0 to 32 ounces, and yet leaving clearance at the top for frothing and aeration within its intended expansion of the materials being mixed. The beater tines 21 have a nominal length of 23/4 inches, and an opposed spacing of 15/8 inches. The length of the beater socket 22 is coordinated with the beater plate 28 so that the lower ends of the tines 21, bent slightly centrally, are positioned closely adjacent to the bottom of the bowl 11. The shaft bevel gear 40 has 24 teeth, and the beater plate bevel gear 41 has 12 teeth. The beater gears 24 are provided with 10 teeth, and the ring gear 45 with 50 teeth. As indicated above, one rotation of the hand crank 15 provides two orbits for the beater plate 28, as well as the beaters 20. During the course of the two orbits resulting from a single rotation of the hand crank 15, each of the three beaters will rotate ten times. When observing the operation of the beaters 20 through the bottom of the bowl 11, a virtual blur of activity whipping and aerating the contents of the bowl 11 is observed. It is this extensive agitation produced in a short period of time which results in excellent aeration and mixing of the contents of the bowl 11, whether the same be egg whites, whipping cream, a chocolate milk drink for the children, or a favorite beverage for the adults.
Because the whipper 10 is readily disassemblable as set forth above, the various parts can be easily washed, and preferably in a dishwasher. To this end, the gears and beaters may be desirably formed from 101 nylons supplied by the Du Pont Company. The bowl 11, gear plate 26 and beater plate 28 as well as the housing 50 can be molded of S.A.N., an acrylanitrile manufactured by the Dow Chemical Company and also known as tyrill 880. If substitute materials are sought, they are desirably ones which will withstand the higher temperature ranges experienced in the normal dishwasher, although for economy purposes, the unit could be molded out of a lesser plastic. The same comments apply, of course, with regard to the double egg separator 110.
In review it will be seen that a whipper 10 has been disclosed and described which is efficient and high speed in operation. The same has the desirable features of a free standing beater assembly, while the bowl 11 may be used for other purposes. In addition, a double egg separator 110 is adapted for coordinate usage with the bowl 11. Furthermore, the entire whipper 10 takes up little more space in a cupboard than an ordinary mixing bowl, and yet affords the numerous additional features inherent in the above description and the product as shown in the accompanying drawings.
Although particular embodiments of the invention have been shown and described in full here, there is no intention to thereby limit the invention to the details of such embodiments. On the contrary, the invention is to cover all modifications, alternatives, embodiments, usages and equivalents of a whipper as fall within the spirit and scope of the invention, specification and the appended claims.
|
A whipper is shown having a crank secured to a gear housing assembly which in turn orbitally drives a beater plate, the beater plate having three beaters secured thereto in removable relationship. The gear housing assembly is proportioned to fit atop a substantially cylindrical bowl, and the beaters with their included tines are proportioned to extend downwardly in open ended fashion. The gear housing assembly includes a housing which is removably secured to the combination of the beater plate and the ring gear plate by means of a bayonet-type fastener at the periphery of both which coacts with the housing, and more particularly the crank to removably secure the same. An ejector is provided within the housing to assist in removing the crank, and free the housing for rotation with respect to the combination of the ring gear plate and beater plate and associated gears to separate the same for purposes of cleaning. The beaters are secured to the beater gears by means of a beater spline which coacts with a snap-head-type fastener at the upper portion of the beater. Additionally, an egg separator may be used to coactingly engage the bowl.
| 1
|
This is a continuation application of U.S. patent application Ser. No. 07/666,840, filed Mar. 8, 1991, the disclosure of which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
This invention relates to ophthalmological surgery techniques which employ an ultraviolet laser used to provide ablative photodecomposition of the surface of the cornea in order to correct vision defects.
Ultraviolet laser based systems and methods are known for enabling ophthalmological surgery on the external surface of the cornea in order to correct vision defects by the technique known as ablative photodecomposition of the cornea. In such systems and methods, the irradiated flux density and exposure time of the cornea to the ultraviolet laser radiation are so controlled as to provide a surface sculpting of the cornea to achieve a desired ultimate surface change in the cornea, all in order to correct an optical defect. Such systems and methods are disclosed in the following U.S. patents and patent applications, the disclosures of which are hereby incorporated by reference: U.S. Pat. No. 4,665,913 issued May 19, 1987 for “Method for Ophthalmological Surgery”; U.S. Pat. No. 4,669,466 issued Jun. 2, 1987 for “Method and Apparatus for Analysis and Correction of Abnormal Refractive Errors of the Eye”; U.S. Pat. No. 4,732,148, issued Mar. 22, 1988 for “Method for Performing Ophthalmic Laser Surgery”; U.S. Pat. No. 4,770,172 issued Sep. 13, 1988 for “Method of Laser-Sculpture of the Optically Used Portion of the Cornea”; U.S. Pat. No. 4,773,414 issued Sep. 27, 1988 for “Method of Laser-Sculpture of the Optically Used Portion of the Cornea; U.S. patent application Ser. No. 109,812 filed Oct. 16, 1987 for “Laser Surgery Method and Apparatus”; and U.S. patent application Ser. No. 081,986 filed Aug. 5, 1987 for “Photorefractive Keratectomy”.
The art has now advanced to the stage at which self-contained laser based systems are sold as stand alone units to be installed in a surgeon's operatory or a hospital, as desired. Thus, hospitalization is not necessarily required in order to perform such ophthalmological surgery. Such systems typically include a p.c. (personal computer) type work station, having the usual elements (i.e., keyboard, video display terminal and microprocessor based computer with floppy and hard disk drives and internal memory), and a dedicated microprocessor based computer which interfaces with the p.c. work station and appropriate optical power sensors, motor drivers and control elements of the ultraviolet laser, whose output is delivered through an optical system to the eye of the patient. In use, after the patient has been accommodated on a surgery table or chair, the system is controlled by the operator (either the surgeon or the surgeon and an assistant) in order to prepare the system for the delivery of the radiation to the patient's eye at the appropriate power level and spatial location on the corneal surface. Patient data is typically entered, either manually via the p.c. work station keyboard or from a memory storage element (e.g., a floppy disk), and the system automatically calculates the beam delivery parameters and displays the resulting calculations on the video display terminal, with an optional hard-copy printout via a suitable printer. The laser is also prepared to deliver the appropriate radiation in accordance with the calculated beam delivery parameters, and the delivery system optics are likewise preconditioned. In some systems, a provision is made for permanently recording on a plastic card made of PMMA (polymethylmethacrylate) a spot image of the laser beam used in the surgical operation. This spot is recorded prior to the operation to ensure that the beam power is properly adjusted and to provide a permanent record of the beam used. PMMA is typically used due to the characteristic of this material of having a closely similar ablative photodecomposition response to that of the human corneal tissue. After the surgery has been performed, the resultant data is typically made part of a permanent record, which becomes part of the patient's file.
Such systems and methods are presently emerging as the technique of choice for ophthalmological surgery to correct various vision defects in humans. However, as a relatively recent development this technique in general is still subject to close scrutiny and careful evaluation by the medical community as well as by certain regulatory agencies (e.g., the Food and Drug Administration in the United States of America). Although the p.c. work station provides some ability to collect pertinent information for the evaluation of system performance and to aid in tracking the efficacy of the surgical technique, as well as to provide quality control assistance to the manufacturer of the system, existing laser systems lack a simple effective control mechanism for this purpose.
SUMMARY OF THE INVENTION
The invention provides a simpe control mechanism for monitoring the actual usage of ophthalmological laser surgery systems, which is relatively inexpensive to implement and highly reliable in tracking information relating to machine usage and patients' data relating to surgeries performed.
In a first aspect of the invention, an ophthalmological laser surgery system is provided with a patient data card read/write device for controlling and monitoring the operation of the laser surgical system in conjunction with a pre-coded patient data card. The data card and read/write device interact in such a manner that the laser surgical system cannot be operated unless an authorized patient data card is inserted into the read/write device. Once the patient data card is recognized by the system as a legitimate and authorized card, the system is unlocked for normal operation. Preferably, during normal operation the beam delivery parameters calculated by the system, as well as other actual surgical operation data (such as the configuration of the delivery system optics, the duration and power of the laser irradiation of the patient's cornea, the coordinates of the projected laser beam, and the like) are recorded on the patient data card to form a permanent record independently of or parallel to the information stored in the p.c. work station. Also, a test spot of the actual laser beam can be permanently recorded onto the patient data card by directing the beam onto a preselected region of the data card to perform an ablation of that region.
In another aspect, the invention comprises a patient data card having encoded therein several kinds of information for use in evaluating and controlling a laser based ophthalmological surgery system and surgeries performed therewith. A first type of information comprises an authorization code required by the surgery system for enablement to an operative state. Preferably, this first type of information includes a code unique to a specific laser surgery system so that a given patient data card can be used on one and only one machine. Further information stored on the card identifies all authorized surgeons, the patient, the patient's past history, the desired prescription or other identifying information regarding the permissible surgery to be performed on that patient, and preoperative diagnostic information for checking the laser system settings. The card may also contain downloadable software for controlling or altering the operation of the laser system. The card may also contain a photograph of the patient, one or more fingerprints of the patient, or a combination of this or other identifier information. In addition, the card preferably contains an ablation region capable of forming and retaining a physical laser ablation imprint of the intended laser treatment for future analysis and comparison.
In use, the card is pre-coded by the system manufacturer or some other control agency, and issued for use with a specific system. If desired, the patient information may be intentionally left blank and provided by the surgeon or some other authorized person prior to the surgical operation. After the surgery has been performed, the actual data pertaining to the surgery is encoded onto the card for future use. Preferably, the data card is issued for a single surgery and is invalidated immediately thereafter, e.g., by permanently recording an invalidation character onto the card.
The data stored on the card can be transferred from the card to any one of a number of interested parties. The surgeon, for example, may transfer the information from the card to a patient data file or some other master file maintained by the surgeon. This can be done at the data card read/write device and the p.c. work station at the site of the laser system. In addition, the information recorded in the patient data card can be transferred to the system manufacturer's files either from the surgeon's office using the p.c. work station and a modem, or directly from the patient data card. In the latter case, the card can be physically transferred to the manufacturer's office by either the surgeon or the patient, or the patient may visit one of a number of convenient sites having a compatible card reader device.
For a fuller understanding of the nature and advantages of the invention, reference should be had to the ensuing detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an ophthalmological laser surgery system incorporating the invention; and
FIG. 2 is a plan view of a patient data card according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, FIG. 1 illustrates a block diagram of an ophthalmological surgery system incorporating the invention. As seen in this Fig., a p.c. work station 10 is coupled to the single board computer 21 of a laser surgery unit 20 by means of a first bus connection 11 . P.C. work station 10 and the subcomponents of laser surgery unit 20 are known components and preferably comprise the elements of the VISX TWENTY/TWENTY excimer laser system available from Visx, Incorporated of Sunnyvale, Calif. Thus, the laser surgery system 20 includes a plurality of sensors generally designated with reference numeral 22 which produce feedback signals from the moveable mechanical and optical components in the laser optical system, such as the elements driven by an iris motor 23 , an image rotator 24 , an astigmatism motor 25 and an astigmatism angle motor 26 . The feedback signals from sensors 22 are provided via appropriate signal conductors to the single board computer 21 , which is preferably an STD bus compatible single board computer using a type 8031 microprocessor. The single board computer 21 controls the operation of the motor drivers generally designated with reference numeral 27 for operating the elements 23 - 26 . In addition, single board computer 21 controls the operation of the excimer laser 28 , which is preferably an argon-fluorine laser with a 193 nanometer wavelength output designed to provide feedback stabilized fluence of 160 mJoules per cm 2 at the cornea of the patient's eye 30 via the delivery system optics generally designated with reference numeral 29 . Other ancillary components of the laser surgery system 20 which are not necessary to an understanding of the invention, such as a high resolution microscope, a video monitor for the microscope, a patient eye retention system, and ablation effluent evacuator/filter, and the gas delivery system, have been omitted to avoid prolixity. Similarly, the keyboard, display, and conventional p.c. subsystem components (e.g., flexible and hard disk drives, memory boards and the like) have been omitted from the depiction of the p.c. work station 10 .
P.C. work station 10 is actively intercoupled with a patient data card writer/reader 40 designed to interact with an individual patient data card 42 schematically illustrated in FIG. 2 . As seen in FIG. 2, the patient data card 42 is similar to a credit card and has a first surface region 43 for carrying visually readable information, such as the name of the patient, the card supplier (e.g., laser surgery system manufacturer, health care provider or the like), the patient's name and any other information which is deemed desirable for visual presentation. Another region 44 is reserved for information identifying the authorized bearer or user of the card, such as a fingerprint or a photograph of the patient. An ablation region or target area 45 is provided for permanently recording the laser beam operating characteristics just prior to or after performance of a surgery. For this purpose, ablation region 45 may comprise an insert of a polymethylmethacrylate, which as noted above has close matching ablative photodecomposition characteristics to that of human corneal tissue. Alternatively, the entire card 42 may be fabricated of PMMA, or some other substance such as polycarbonate which has similar ablation characteristics to PMMA. The purpose of the ablation region 45 is to provide a permanent ablative photodecomposition record produced by the actual laser beam used in the surgery.
Patient data card 42 is preferably an optical memory card of the type manufactured and marketed by Drexler Technology Corporation under the trademark LaserCard, which is a credit card sized optical data storage device capable of holding more than four megabytes of write once/read many (WORM) data. Similarly, the data card writer/reader 40 may be a known unit compatible with the Drexler optical memory card. If desired, a suitable magnetic memory card may be employed along with a compatible card writer/reader device 40 .
The patient data card 42 is initially provided with read only information optically encoded into the subsurface recording layers (not visible in FIG. 2 ). This information includes the serial number or other identifying characteristic of a specific laser surgery system 20 so that the data card 42 can only be used with a specific system 20 . The purpose for this limitation is to provide controlled information relating to the amount of use of the system 20 and a match between the identity of the system 20 and the actual beam used during the eye surgery (the ablation record permanently formed in ablation region 45 of the data card 42 ). In addition, other qualifying data may be permanently recorded by the card producer, such as the personal identification number of the surgeon or surgeons (or other personnel) qualified to operate the specific system 20 , the prescription of the patient to control the amount and type of laser surgery on a particular patient, the eye upon which surgery will be allowed (e.g., right eye only, left eye only or both, including any differences in prescription between the two eyes), and any other relevant and pertinent information deemed desirable for monitoring the specific patient and the specific system 20 .
In order to render the system 20 operative, an authorized data card 42 must be read by the writer/reader 40 , and this information must then be presented to the p.c. work station 10 , which functions as the master control for the system 20 . Once an authorized card has been inserted and identified, the operation of the system 20 proceeds in a somewhat conventional fashion in that the beam delivery parameters are calculated in the p.c. work station 10 and transferred to the single board computer 21 for control of the various motors 23 - 26 , the laser 28 and the delivery system optics 29 . At some time during the surgery procedure, preferably just prior to the actual irradiation of the eye 30 , the data card 42 may be installed in a fixture (not shown) in the output beam path of the laser 28 (i.e., within the delivery system optics 29 or at the output side thereof and the laser 28 is pulsed at the surgical rate and power to form the permanent record of the laser beam in the ablation region 45 . Thereafter, the surgery is performed and the post operation data is measured, calculated and stored in an appropriate memory location within the p.c. work station 10 . Certain information may then be recorded onto the patient data card 42 by means of the data card writer/reader 40 so that the data card 42 obtains post operative information useful for monitoring purposes. For example, the date of the operation, the total length of the exposure of the corneal surface of the eye 30 to the laser beam 28 , the pulse duration, the time between pulses, the exact coordinate settings of the laser beam radiation throughout the operation may all be recorded on the patient data card 42 . This information is then available until destruction of the card for any informational purposes the surgeon, the patient, the health insurance company, the regulatory agency and the system manufacturer may require. In addition, if desired the card 42 may be permanently altered to prevent repeated use with specific surgery system 20 or any other system 20 as an added check on the operational use of a specific system 20 .
The patient data card 42 may contain program instructions required for the operation of the system 20 . In such an embodiment, p.c. workstation 10 receives the necessary program instructions from the card 42 using a conventional software downloading operation at the beginning of system operation. At the conclusion of system operation, the program instructions resident in the p.c. workstation 10 are erased to prevent subsequent operation of system 20 without a fresh data card 42 .
As will now be apparent, laser surgery systems provided with the personal data card functioning as a control token offer an unparalleled degree of control over the use of the surgery system and afford a rigorous information gathering capability for quality control and monitoring studies. In particular, every single use of a given surgery system 20 can be accurately monitored by use of the patient data card 42 , and the actual operating characteristics and optical parameters can be permanently stored in an independently verifiable manner for future study. Such a capability is particularly important for laser surgery systems still subject to regulatory control, as well as to fully approved laser surgery systems for which cumulative historical data is highly desirable. The added cost of the data card reader/writer 40 is nominal compared to the overall system, and the patient data card is no more inconvenient to carry and use than any conventional credit card.
While the above provides a full and complete disclosure of the preferred embodiments of the invention, various modifications, alternate constructions and equivalents may be employed as desired. For example, while the invention has been described with specific reference to an optically encoded data card 42 , data cards having read/write storage capability and using magnetic or semiconductor technology may be employed, as desired. In addition, other laser surgery systems than the VISX system noted above can be used to implement the invention. Therefore, the above description and illustrations should not be construed as limiting the invention, which is defined by the appended claims.
|
An ophthalmological laser surgery system having a laser, associated elements for delivering an optical beam from the laser to a patient eye location, a control unit for controlling the operation of the system and a system input/output device, is enabled by a patient data card. The data card originally contains both patient background and system control information, which is transferred to the control unit via the input/output device. During system operation, newly generated information, such as laser beam power, is stored in the data card to provide an independent record of the surgical procedure actually performed. After one use, the data card is invalidated to prevent further use.
| 0
|
RELATED APPLICATIONS
This application is a continuation-in-part of commonly-assigned application, Ser. No. 08/253,535, filed Jun. 3, 1994, entitled "Recording And Reproducing An MPEG Information Signal On/From A Record Carrier" in the names of R. W. J. J. Saeijs, I. A. Shah and Takashi Sato, which is in turn a continuation-in-part of commonly-assigned application, Ser. No. 08/225,193, filed Apr. 8, 1994, entitled "Recording And Reproducing An MPEG Information Signal On/From A Record Carrier" in the names of W. J. Van Gestel, R. W. J. J. Saeijs and I. A. Shah.
BACKGROUND OF THE INVENTION
The invention relates to a system for recording and playing back an MPEG information signal in tracks on a record carrier, and specifically a record carrier of the Digital Video Cassette Recorder (DVCR) type.
An MPEG information signal comprises a succession or stream of transport packets, which includes a data compressed digital video signal and a corresponding data compressed digital audio signal (and sometimes data signals), for broadcasting purposes or for transmission via a cable network. The MPEG information signal is in the form of transport packets having either an equal length or a variable length in time. In both cases, however, a transport packet comprises 188 bytes of information, the first byte of which is a synchronization byte.
A transmission such as an MPEG information signal in the form for recording on and reproduction from a record carrier, such as a magnetic record carrier as a tape, require special measures to be taken in order to realize such kind of transmission via the known tape format.
Storing a packet sequence number has its advantages if an MPEG data stream is received having a constant bit or transport rate without any gaps between packets, and comprising a number of different video programs interleaved in the MPEG data stream. Generally, such data stream may have too high a bit rate for recording the total data stream on the record carrier. For example, the MPEG bit rate for cable transmission is 45 Mbps, whereas the record carrier typically records with a 25 Mbps bit rate. The recording arrangement now comprises a program selector for retrieving one or multiple programs from the MPEG data stream so as to obtain the MPEG information signal for recording. As information corresponding to only one program is included in a MPEG transport packet, such a program selector selects, which is per se known, only those transport packets from the MPEG data stream that comprise information corresponding to wanted program(s). That means that some packets of the original MPEG data stream received are deleted. Upon reproduction, however, a valid MPEG video signal in accordance with the MPEG standard, however now comprising only the wanted programs, must be regenerated or recreated. By a "valid" MPEG signal or transport stream is meant a stream that satisfies the following requirements:
1. The program clock reference (PCR) in the packet is OK. The PCR is, typically, a 33 bit value of a sample of the local clock in the transmitter encoder. The PCR is used for clock recovery so that in the decoder, the local clock can be sync'd to the encoder local clock.
2. Accumulated change to each PCR through the network must be kept within the limit specified by MPEG.
3. The decoder transport buffers do not overflow.
Such regenerated data stream should have the transport packets that were selected upon recording in the same order. Upon recording a sequence number can be added to each transport packet received, also for any packets that will be deleted. The sequence numbers of the packets that are selected and stored may be stored in the third block section of the signal blocks in which a transport packet is stored. Upon reproduction, a sequence of numbers is retrieved, where subsequent numbers will not necessarily be next higher numbers. In that situation one or more dummy packets must be inserted so as to regenerate the replica of the original MPEG data stream.
It will also be apparent that a reproducing arrangement will be needed which is adapted to each specific embodiment of the recording arrangement, so as to enable a reproduction of the MPEG information signal recorded on the record carrier.
The two related copending applications, whose full contents are incorporated herein by reference, describe such systems which solve a problem arising from the asychronous nature of a channel represented by the DVCR and the necessity for preserving the timing critical data incorporated in the MPEG transport stream so that it can be reconstituted as a valid MPEG information signal upon playback for reproduction on a conventional TV set. The systems described involve tagging transport packets of the MPEG data stream, before inputting to the channel, with timing information, and using the timing information at the output end of the channel to recreate the proper data timing. Various schemes are described for packing the timing information tags with each or a plurality of transmission units of the transport stream. Using this basic tagging mechanism, transport streams of various types can be recorded and played back without losing any of the information in the original transmission. Where the transport rate of the transport stream is unknown, or with gaps between the transport packets (i.e., bursty), or the transport rate changes, then the referenced related applications describe ways of handling such data streams.
When, on the other hand, the transport rate of the incoming transport stream is constant and unknown, the related applications also describe schemes for handling this situation. Thus, using a combination of Time-Of-Arrival (TOA) and Sequence-Of-Arrival (SOA) tagging as described in the related applications, an MPEG-2 transport stream of unknown but constant transport rate can be recorded and recreated on playback. In this case, however, there must not be any gaps between the transport packets at the input.
BRIEF SUMMARY OF THE INVENTION
An object of the invention is a system for recording and playback of MPEG information using a DVCR.
A further object of the invention is a system for generating a fixed-rate, constant transport stream from an incoming unknown transport stream, which is possibly at varying rate, and/or bursty.
Another object of the invention is a system for generating a fixed-rate, constant valid MPEG transport stream from an incoming unknown MPEG transport stream, which is possibly at varying rate, and/or bursty.
Still another object of the invention is a remuxing scheme for MPEG transport streams which is simple enough to implement in DVCR or other consumer applications.
In accordance with one aspect of the invention, the packets are processed serially through a remuxer to obtain a constant rate and delivered to and consumed by one or more target decoders, for example, inside a TV set or in a set-top decoder. To prevent overflow of the transport buffers inside each of these decoders, a single monitor is provided which monitors all of the transport buffers and delivers to each the packets wanted timed in a manner that will avoid buffer overflow and loss of information. This aspect of the method of the invention requires that the transport packets be restamped with a new PCR. Looked at from another view, this aspect of the invention basically involves remuxing the transport stream to a known and fixed case, and then applying the solution described in the referenced related applications for the case of a transport stream with a constant and known transport rate.
The invention is not limited to application to an MPEG information signal and can also be applied to asychronous channels other than a DVCR. In addition to transmitting MPEG data streams, there are various other applications that may require the transmission of timing critical data over an asynchronous channel. Asynchronous here means that the physical data rate of the channel is different from the transport rate, the rate of the data to be transmitted, so that the bitwise timing of data is not maintained through the channel transmission.
In the MPEG transport stream as an example of timing critical data, the relative arrival time of a datum which represents timing information of the transport stream, i.e., the PCR, must not be changed beyond a specified tolerance through transmission without changing the PCR value accordingly. This is because otherwise, the Phase Lock Loop (PLL) circuitry of a decoder will fail to regenerate the data clock, and the buffers may under/overflow. This problem of how to transmit timing critical data over an asynchronous channel without changing any datum to be transmitted also exists where the asynchronous channel is a computer network, a telephone network or a digital interface, e.g. P1394.
In accordance with another aspect of the invention, an improved remux method is described which does not have to perform complex de-multiplexing/re-multiplexing but relies instead on scheduling each packet without changing the order of the useful packets. This method offers the important advantage that the required hardware is much less expensive and thus easier to implement in low-cost consumer equipment.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described the preferred embodiments of the invention, wherein like reference numerals depict the same or similar components.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 corresponds to FIG. 18 of the second related application and shows a system for handling a transport stream with a known and constant transport rate, from both the recording and playback standpoints;
FIG. 2 shows an example of the input and output data streams from the apparatus of FIG. 1;
FIG. 3 illustrates a remuxing and DVCR recording system;
FIG. 4 shows an example of the input and output data streams from the apparatus of FIG. 3;
FIG. 5 is a schematic block diagram of a packet processor feeding apparatus with a target decoder;
FIG. 6 is a block diagram of one form of remuxing system in accordance with the invention;
FIG. 7 is a block diagram combining the system of FIG. 1 and the remuxing system of FIG. 6 as one form of another embodiment of the invention;
FIGS. 8A and 8B are graphs illustrating the effects of a remuxing scheme which does not monitor the transport buffer under two different conditions;
FIGS. 9A and 9B are graphs illustrating the effects of a remuxing scheme which does monitor the transport buffer under the same two different conditions of FIGS. 8A and 8B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order to better understand the invention, we will first describe the system described and claimed in the two related applications for handling a transport stream with a constant, known transport rate.
FIG. 1 shows such a system applied to an MPEG application where R represents the transport rate of the MPEG data stream subdivided into transmission units in the form of a succession of transport packets from a digital interface (D-I/F). In the example given, the incoming transport rate is 45 Mbps, to be recorded on a DVCR at 25 Mbps, and then recreated as a valid MPEG signal at 45 Mbps, for playback on a standard TV set.
The incoming data stream from D-I/F is received by a known tagging means 10 for tagging each incoming packet with a SOA tag requiring only a counter 11 incrementing at the arrival of each transport packet. The tagged packets then go to a selection means 12 for selecting the desired program material, and the selected packets stored temporarily in a local buffer 15. As explained in the referenced related applications, trickmode packets can be generated from the incoming transport stream at block 16 and intermixed with the desired program material by a MUX block 17 at the desired transport rate for recording on the DVCR. The tagging bits are recorded onto the DVCR tape along with the corresponding transport packets using the extra bits available from the 2 to 5 sync blocks mapping as described in the related cases.
On playback, each recorded packet is read out at its correct sequence according to the SOA stamp information under control of a read control block 20 via a local buffer 22. A DE-MUX block 21 acts to separate the packet stream, and the gaps formed by the non-selected program material packets in the output stream are filled in by supplying Null packets from a Null packet generator 23. During playback, each time a "discontinuity" in the SOA tag is detected, it is assumed to have come from a transport packet that has not been recorded. These "missing" packets are replaced with the Null packets. All transport packets are thus output at the known and constant transport rate.
FIG. 2 gives an example of the transport stream resulting. In the upper diagram, as an example, the input transport stream is a two program stream: programs A and B. We wish to record only program A, and hence strip out the B packets in the selection block 12. On playback, all the packets belonging to program A are reproduced at precisely their original times and rates, and the gaps are filled in with the Null packets (lower diagram). If the input stream was a valid MPEG signal, the output stream will also be valid.
As will be clear from the foregoing explanations, to maintain the interoperability between MPEG applications, it is necessary for the DVCR to generate a valid MPEG transport stream, preferably at a fixed-rate and constant (i.e., without any gaps between packets). Generating a fixed-rate constant transport stream for input to the apparatus of FIG. 1 from an incoming unknown transport stream, which is possibly at varying rate and/or bursty, meaning that there are gaps between the packets, is equivalent to generating a new transport stream by so-called remuxing. Remuxing by DVCR is comprised of selection of necessary packets, rescheduling of the timing of each packet, and multiplexing of the selected packets with Null packets to fill out the gaps in the transport stream. Whenever remuxing is done, the following remux requirements must be met:
(a) Timing jitter of each PCR (incorporated in each transport packet) must be kept within an acceptable limit.
(b) Accumulated change to each PCR through the network must be kept within the limit specified by MPEG.
(c) Generated transport stream must not overflow the transport buffer of each elementary stream decoder.
One form of apparatus according to the invention is illustrated in FIG. 3, a combination of SOA and remuxing. In this case, after the remuxing 80, the packet stream at the new rate is tagged 81 and any Null packets removed in the local buffer block 82. However, in this case, the duration of the output packets is different. FIG. 4 shows in the upper diagram the input stream to the remuxer 80, and in the lower diagram the output stream to the D-I/F. The transport rate is now constant, but the packets need restamping with new PCRs because the old PCRs are no longer valid. Another problem appears, illustrated in FIG. 5.
FIG. 5 shows schematically a valid MPEG signal input to a packet processor 84, which may be the system of FIGS. 1 and 3. It outputs a valid transport stream like that of FIG. 4 (lower diagram) to, for example, a selector 86 selecting packets for each elementary stream decoder 85 which includes a transport buffer 87, referred to herein as the "target decoder" and "target buffer". For the system to perform properly, the target buffers of each decoder provided must all be managed to avoid overflow. The problems are illustrated in FIGS. 8A and 8B.
In these figures, X represents the input transport rate, Y represents the output transport rate, and R represents the read-out or emptying or leak rate of the transport buffer in the target decoder. FIG. 8A shows the effect of remuxing without monitoring of the transport buffer where R<Y<X. The row labelled Input is the sequence of input transport packets, and the row below labelled output is the sequence of output transport packets over a time t. The graph above indicates the fullness of the transport buffer over time t, with the dashed line 29 at top labelled Th representing a full buffer, and the dotted diagonal lines 30 representing the input stream. Where the solid line curve 31 representing the output stream crosses the threshold line 29, shown at 32, bits of certain output packets will be lost, which will occur with packets 7, 10, etc. The case illustrated is where the input rate is faster than the output rate.
In FIG. 8B, the case where the input rate is slower than the output rate is given, represented by R<X<Y, with the dotted lines 34 again representing the input stream, and the solid line curve 35 again representing the output stream. Here, too, without monitoring, when the curve 35 crosses the threshold line 29, shown at 36 and 37, bits of certain output packets will be lost, which will occur with packets 6, 9, etc.
A feature of the invention is a remuxing scheme for MPEG transport streams which is simple enough to implement on DVCR or other consumer applications.
This aspect of the present invention is based upon the following new concepts and understandings.
1. Incoming transport streams have small enough timing jitter; hence, requirement (a) can be met simply by restamping PCR's, using an appropriate local clock.
2. Incoming transport streams have enough head room for the PCR change; hence, the requirement (b) can be met by the remuxing scheme described below. By "head room" is meant the unused portion of the limit as defined in the MPEG standard.
General remuxing includes clock regeneration of each program, de-multiplexing of the input to separate each elementary stream, keeping track of each transport target buffer, calculation of a new schedule, re-multiplexing of the elementary streams, restamping of PCR, and so on. As will be recognized, such general remuxing requires complex software and hardware not implementable in typical low-cost consumer appliances. A feature of our invention is based on a simpler remuxing scheme, which does not perform de-multiplexing/re-multiplexing but simply schedules each transport packet without changing the order of the useful packets. This approach requires certain basic assumptions:
1. The total net rate of the wanted program(s) in the input transport stream must be less than the output transport stream rate (the remux rate);
2. The input transport stream rate can, however, be unknown, bursty and/or at any rate, higher or lower;
3. The remux rate is known, fixed and constant.
In accordance with an aspect of the method of the present invention, the remuxing goes as follows, reference being made to FIG. 6 which is a block diagram of one form of remuxing apparatus in accordance with the invention:
1. The necessary packets are selected from the incoming transport stream by a filter or selector 40.
2. The packets containing the PCR are tagged 41 with the sampled value of a local clock 39.
3. Each packet is stored and kept in a local buffer 42 until it is read out to a packet store 44.
4. Whenever the packet store 44 is empty and there is at least one packet in the buffer 42, the first packet in the buffer 42 is read out and moved to the packet store 44. Necessary information of the packet is sent to a scheduler 45 at the same time.
5. The scheduler 45 checks whether outputting of the packet in the packet store 44 will overflow the transport buffer 87 of the corresponding elementary stream decoder 85 (FIG. 5) and signals it to a MUX 47.
6. If the packet store 44 has a packet and the scheduler 45 signals that the decoder transport buffer will be OK, the MUX 47 selects and reads out the transport packet in the packet store 44. Otherwise, the MUX 47 selects and outputs a Null packet from a Null packet generator 49. The packet in the packet store 44 remains there until it is read out.
7. Each PCR value in the transport packet transmitted by the MUX is modified in a PCR restamper 50 using the following equation:
PCR.sub.new =PCR.sub.old +(Clock.sub.current -Clock.sub.tagged)-Delay.sub.max (1)
where,
PCR new : New PCR value after restamping;
PCR old : Old PCR value before restamping;
Clock current : Current Clock value at output time restamping 50;
Clock tagged : Clock value tagged 41 at reception of the packet;
Delay max : Maximum delay through the remux operation, which is a constant value to ensure that each PCR value never increases.
The scheduling scheme is an important feature of this invention. The main purpose of scheduling is to ensure that the transport buffers in the decoders never overflow. Scheduling of packets takes a lot of work if it is done in a brute force manner because it involves keeping track of the transport buffer fullness of every elementary stream in parallel. This may be too complicated for consumer applications apparatus, hence, we created a simpler way to do the job. This is based upon the following:
1. We can derive the transport buffer (85-88 in FIG. 5) emptying or leak rate (read-out rate) of each elementary stream from the information carried in the input transport stream. For example, the transport buffer leak rate is 54 Mbps for the Grand Alliance HD Video standard, 18 Mbps for SD Video and 2 Mbps for Audio, etc. We can know that if the remux rate is less than the transport buffer leak late, no transport buffer monitoring is necessary because the transport buffer never overflows. Hence, we can reduce the number of transport buffers that we need to monitor. Transport buffer monitoring can be further simplified using the following approaches:
1. The buffer fullness of each transport buffer increases monotonically from the beginning of each received packet through the end of the packet; hence, we need to check the buffer fullness only at the end of each packet.
2. Remux knows its own output transport rate (the remux rate) as well as the transport buffer leak rates for each elementary stream; hence, it can know how much the buffer fullness of a transport buffer will change by sending a packet and by not sending a packet to the transport buffer, using the following equations:
Leak=R.sub.leak ·T.sub.packet (2)
Delta=S.sub.packet -Leak (3)
where,
Leak: Change of transport buffer fullness per one-packet period when transport buffer receives no packet;
R leak : transport buffer leak rate;
T packet : Packet period, i.e., S packet /R remux ;
S packet : Packet size;
R remux : Remux rate;
Delta: Change of transport buffer fullness per one-packet period when transport buffer receives one packet.
Table 1 below shows an example of a parameters table that can be used for transport buffer monitoring.
______________________________________ Leak Delta Rate.sub.leak bits (bytes) bits (bytes)______________________________________SD 18 Mbps 1,082 (135) 422 (53)Audio 1 Mbps 61 (8) 1,443 (180)Others ≧R.sub.remux Mbps NA or 0 NA or 0______________________________________ (S.sub.packet = 188 bytes, R.sub.remux = 25 Mbps)
This table can be expanded if there are other data types which have known transport buffer leak rates and require transport buffer monitoring.
3. Using the above results, the buffer fullness of each transport buffer can be calculated using the following equations:
B.sub.prev =B.sub.last (i)-Leak(i)(C.sub.current -C.sub.last (i)-1)(4)
where,
i: Index of the elementary stream which the current packet belongs to;
B prev : transport buffer fullness of the i-th elementary stream just before receiving the current packet;
B last (i): transport buffer fullness of the i-th elementary stream when the transport buffer has just finished receiving the last packet;
Leak(i): transport buffer leak rate of the i-th elementary stream per one packet period;
C current : Value of output packet counter for the current packet;
C last (i): Value of output packet counter for the last packet of the i-th elementary stream
If B.sub.prev <0, then B.sub.prev = (5)
B.sub.current =B.sub.prev +Delta(i) (6)
where,
B current : transport buffer fullness of the i-th elementary stream when the transport buffer has just finished receiving the current packet;
Delta(i): Change of transport buffer fullness of the i-th elementary stream by receiving one packet.
The scheduling algorithm goes as follows in the preferred embodiment:
Step 1.
At every interval T packet , check if a whole packet is in the packet store 44. If there is a packet (the current packet), go to Step 2, otherwise, go to Step 5.
Step 2.
If the transport buffer leak rate of the i-th elementary stream, to which the current packet belongs, is obtained for the first time, calculate Leak(i) and Delta(i), using equation (2) and equation (3), respectively, and initialize the parameters for transport buffer monitoring as follows, and go to Step 3:
B.sub.last (i)=0(7) (7)
C last (i)=C current . (8)
Step 3.
Calculate B current corresponding to the current packet, using equation (4), equation (5) and equation (6), and go to Step 4.
Step 4.
If B current is equal to or less than the transport buffer size, output the current packet and update the parameters as follows and go to Step 6. Otherwise, go to Step 5:
B.sub.last (i)=B.sub.current (9)
C.sub.last (i)=C.sub.current. (10)
Step 5.
Output a Null packet and go to Step 6.
Step 6.
Increment the output packet counter as follows and go to Step 1:
C.sub.current =C.sub.current +1 (11)
This simple scheduling scheme requires only a series of simple calculations per each packet period regardless of the number of the elementary streams in the transport stream and yet can prevent transport buffer overflow from happening. Moreover, as will be appreciated, where the system of FIG. 6 is employed as the packet processor of FIG. 5, it is capable of monitoring the buffer fullness in each of the target decoders 85 provided while delivering to them valid MPEG streams. This is because the above-noted algorithm can be executed each time a packet arrives at the store 44, because the scheduler 45 knows which data stream the packet belongs to, is keeping track of the packets of each separate data stream, and knows the leak rates of the respective transport buffers in the respective target decoders 85. Thus, in a serial packet processing system, a single scheduler is able to monitor multiple decoders.
If we combine the remuxing scheme explained above in connection with FIG. 3 with the overall recording proposal described in the referenced copending application, and remove redundancy, we can obtain a total DVCR solution, which is illustrated in FIG. 7. The same reference numerals as are used in FIGS. 1 and 6 represent the same components in FIG. 7. The new components which function similarly to those previously described include a packet sequencer tagger 60 corresponding to the tagger 10, a second local buffer B corresponding to local buffer 15, and a MUX 62 which muxes tagged and restamped transport packets with the trickmode and null packets in the recording part prior to recording on the media. Whereas the previous Null packets meant MPEG Null packets to create a valid MPEG stream, these null packets 49 are used merely to fill gaps in the recording stream and serve no MPEG function. In the playback part, there is provided a filter 65 that serves to strip off undesired fill packets and the resultant transport stream is stored in a local buffer C 66 corresponding to local buffer 22, a decoding packet store 67 and decoding scheduler 68 which performs the reverse functions of the scheduler 45 in the encoding part, and a MUX 69 corresponding to block 17.
Recording then goes as follows:
1. The necessary packets are selected by the filter 40.
2. The packets containing PCR are tagged 41 with the local clock 39.
3. Each packet is stored and kept in local buffer A 42 until it is read out.
4. Whenever the packet store 44 is empty and there is at least one packet in buffer A 42, the first packet in buffer A 42 is read out and moved to the packet store 44. The necessary information of the packet is sent to the scheduler 45 at the same time.
5. The scheduler 45 checks whether outputting the packet in the packet store 44 will overflow the target transport buffer of the corresponding elementary stream or target decoder, as described above, and signals it to the MUX 62.
6. If the packet store 44 has a packet and the scheduler 45 signals that the target transport buffer will be OK, the packet in the packet store 44 is read out. The packet in the packet store 44 remains there until it is read out.
7. Each packet containing PCR is restamped 50 its PCR value using equation (1).
8. Each packet is tagged 60 with its packet sequence No., which may have discontinuity due to the scheduling.
9. Each packet is stored and kept in the local buffer B 61 until it is read out.
10. The packets read out from the buffer B 61 are multiplexed 62 with trickmode packets 16 and, if necessary, null packets 49, according to a trickmode recording scheme.
Playback goes as follows:
1. The necessary packets are selected by the filter 65.
2. Each packet is stored and kept in the local buffer C 66 until it is read out.
3. Whenever the packet store 67 is empty, a packet is read out from the buffer C 66 and moved to the packet store 67. The Packet Sequence No. tag of each packet is sent to the scheduler 68.
4. The scheduler 68 checks whether the Packet Sequence No. matches an internal packet counter (not shown or incorporated in the scheduler) and signals OK if both match.
5. If the scheduler 68 signals OK, the MUX 69 selects and reads out the packet in the packet store 67. Otherwise, the MUX 69 selects and sends out a Null packet. Every packet is sent out at the remux rate. FIG. 7 thus combines the remux scheme of FIG. 6 with the necessary components to allow recording and playback from a DVCR.
FIGS. 9A and 9B show the improvement obtained under the same conditions described above in connection with FIGS. 8A and 8B, respectively. In essence, shown in FIG. 9A, the rescheduler has delayed blocks 7 and 10, etc. (see arrows 75 and 76) long enough to prevent target buffer overflow. Similarly, blocks 6 and 9, etc. have been delayed at arrows 77 and 78 as shown in FIG. 9B to prevent overflow and loss of information.
In this way, a DVCR can reconstruct at playback, without loss of information, a transport stream that has the rate and timing exactly as scheduled by the remux at recording. With this scheme, the remux rate can be equal to or higher or lower than the recording rate as long as the net transport stream rate at the remux is equal to or less than the recording rate. Note that in the FIG. 6 embodiment, Null packets 49 are added. If substituted for the remuxer 80 in the FIG. 3 embodiment, Null packets would have to be deleted 82. This superflous addition and deletion of MPEG Null packets is avoided in the FIG. 7 embodiment.
In the block diagrams of the figures, only the data flow is shown by the arrows. Those skilled in the art will understand that several of the blocks are interconnected for command and control signals that are not shown in the figure.
As previously indicated, the invention is also applicable to other data formats and other ways of preserving the critical timing data. It will also be appreciated that the circuitry and hardware to implement the various blocks shown, including software to the extent needed, will be evident to those skilled in the art not only from the detailed information supplied in the referenced related applications, but also from the below listed references, whose contents are also incorporated herein by reference:
(1) European patent application no. 492,704 (PHN 13.546)
(2) European patent application no. 93.202.950 (PHN 14.241)
(3) European patent application no. 93.201.263 (PHN 14.449)
(4) Grand Alliance HDTV System Specification, Draft document, Feb. 22, 1994.
(5) U.S. Pat. No. 5,142,421 (PHN 13.537)
While the invention has been described in connection with preferred embodiments, it will be understood that modifications thereof within the principles outlined above will be evident to those skilled in the art and thus the invention is not limited to the preferred embodiments but is intended to encompass such modifications.
|
A method of transmitting timing critical data via an asynchronous channel. The timing critical data can be an MPEG transport stream of packets. The asynchronous channel can be a computer or telephone network, a digital storage media such as a digital VCR, or a digital interface. The packets are processed serially through a remuxer to obtain a constant rate and delivered to and consumed by one or more target decoders, for example, inside a TV set or in a set-top decoder. To prevent overflow of the transport buffers inside these decoders, a single monitor-scheduler is provided which monitors the transport buffers and delivers to each the packets wanted scheduled so as to avoid buffer overflow and loss of information. The method also includes restamping the transport packets with new PCRs. The remuxing scheme is simple enough to implement on DVCR or other consumer applications. Also described is a method for recording the output stream which selects out desired program material and tags the transport packets with SOA tags.
| 7
|
FIELD OF THE INVENTION
The present invention relates to the control of fed-batch or continuous fermentation processes. In fermentation processes where a maximum biomass yield is required or the build-up of acids such as acetic acid might become toxic or may be detrimental to the product, the presence of such acids is undesirable.
BACKGROUND AND PRIOR ART
Correct control of medium addition rate to fermentation processes where accumulation of metabolites is to be prevented is a primary objective. Some microorganisms produce undesirable metabolites when fed at too high a medium addition rate. Examples are Bakers' yeast and Escherichia coli (De Deken, 1966; Doelle, 1981). Bakers' yeast will produce fermentation products such as ethanol and acetate when too much sugar is added (Fiechter et al, 1981). During the production of Bakers' yeast this will cause a loss of cell and product yield (Fiechter et al, 1981). The bacterium E. coli will produce acids such as acetic acid at sugar excess (Doelle, 1981). Also when microorganisms are used for the production of heterologous products the formation of these metabolites is undesirable, especially when these have a toxic or inhibitory effect. Acetate, ethanol and organic acids in general can be toxic to cell metabolism (Moon, 1983; Pampulha & Loureiro-Dias, 1989). This will become particularly apparent when growing mutant strains, which are often less robust than the wild-type strain. Therefore, good control of the feed addition rate to a fed-batch or continuous fermentation process is desirable.
Many ways of on-line computer control are possible. For example CO 2 evolution rates and O 2 consumption rates are often analysed on-line to calculate the so-called Respiratory Quotient (RQ) (Wang et al, 1977). The RQ is the CO 2 evolution rate divided by the O 2 consumption rate. Under sugar-limited conditions the RQ will be approximately 1·0 to 1·1, the exact value depending on the strain. However, when a culture of Bakers' yeast is fed at too high a sugar addition rate ethanol will be produced and the RQ values in that case will then be significantly higher than 1·1 (Wang et al, 1977; Fiechter et al, 1981). This then can be used to change the feed rate such that the RQ decreases (Wang et al, 1977).
EP 283 726 (Hitachi) and Turner et al (1994) disclose the control of fermentations by monitoring acetate levels, but the control was achieved by sampling the medium and using HPLC or similar discontinuous methods. HPLC has also been used to measure glucose levels in order to control acetate accumulation (Sakamoto et al, 1994).
The problem which is solved by the present invention is to provide an alternative and improved method of controlling such fermentations.
One aspect of the present invention provides a process of culturing a microorganism in a culture medium in which process the addition of feed medium is controlled by using the production of a by-product as a measure of the culture conditions, characterised in that the by-product is an electrically charged metabolite produced by the microorganism, and in that the production of the metabolite is monitored by measuring the conductance of the culture medium.
The evolution of electrically charged metabolites has not been used previously to control the addition of feed medium. RQ, for example, is 1 (one) when acetate is produced in a sugar fermentation, so RQ measurement is not useful, as this RQ value is near that obtained during sugar-limited growth. Electrical conductivity has been used to measure the formation of relatively large amounts of desired organic acids such as lactate in yogurt cultures and other lactobacillus fermentations (Latrille et al, 1992; Belfares et al, 1993), acetic acid production (SU-A-1 495 367) and for the control of salt content of fermentation cultures (Soyez et al, 1983). In the latter case, inorganic salts were added to the medium, and the technique simply measured those artificially added salts in order to maintain a desired salt concentration. Conductivity has also been used to measure cell density (JP-A-2 109 973). Conductivity has not been used to prevent and overcome the accumulation of undesirable acids such as acetate, of which even small amounts are indicative of the fermentation going awry. We have discovered that where the formation of organic acids such as acetate is undesirable, an increase in electrical conductivity can be measured on-line and used for a feed-back system to control the feed rate in a similar way as the RQ can be used. In this invention it is shown that increases in an on-line electrical conductivity signal during a fermentation process are sufficiently indicative of the formation of undesirable acids to be used to correct the feed addition rate in order to prevent and overcome accumulation of these acids. Hence, although for many years it has been known to measure (in an off-line biochemical assay) the production of acetate in order to see whether the fermentation control based on other parameters (eg CO 2 evolution) is working satisfactorily (see EP 315 944, 1989), nobody had measured acetate evolution electrically to control fermentation.
Obviously, the microorganism and the fermentation medium should be such that an electrically charged metabolite is potentially produced and the fermentation should be one in which controlling the addition of feed medium is desirable. Equally, the fermentation should not be one in which an electrically charged product is desired, for example a lactic acid fermentation. Microorganisms for which the present invention is useful include bacteria such as E. coli or Bacilli and fungi such as yeasts, for example Saccharomyces spp., especially S. cerevisiae, or filamentous fungi. However, the invention is in principle applicable also to the culturing of protozoa, plant cells and animal cells, for example insect cells or mammalian cells such as CHO (Chinese Hamster Ovary) cells.
The metabolite is typically an organic acid such as acetate, pyruvate, lactate or a citric acid cycle intermediate such as citrate, isocitrate, α-ketoglutarate, succinate, fumarate, malate or oxaloacetate.
The microorganism may be cultured to produce either biomass, a desired metabolite or a polypeptide which is native or heterologous to the microorganism. Hence, for example, the microorganism may be a yeast which contains and expresses a polynucleotide encoding human albumin. Advantageously, the polypeptide is secreted from the yeast into the surrounding medium and recovered therefrom.
The measurement of the conductivity is very sensitive and can detect acid concentrations as low as 1 mM. This means that it is a useful alternative, or addition, to the generally accepted use of on-line RQ measurements.
The control may be achieved by use of a probe, capable of measuring conductivity, inserted in a fermenter and linking the signal to an on-line computer. A conductivity probe can be very simply inserted in a standard pH probe port. A computer algorithm can then calculate the change in conductivity or conductance over a chosen time period. If the change in conductivity is greater than a chosen limit, a reduction in the feed medium addition rate will automatically be applied by the computer algorithm. This will then promote a co-consumption of the feed substrate and the accumulated metabolites present, and prevent further production thereof. The choice of time period and conductivity change limit will be dependant on the exact nature of the fermentation process.
DETAILED DESCRIPTION OF THE INVENTION
Preferred aspects of the invention will now be described by way of example and with reference to the accompanying drawings in which:
FIG. 1 is a representation of some key parameters during a fed-batch fermentation of a yeast strain producing recombinant human albumin. The points at which the feed addition was started and finished are indicated by arrows.
FIG. 2 shows parameters for part of a fed-batch fermentation during which, at the indicated time, a deliberate, sudden 20% feed rate increase was applied.
FIG. 3 is a similar experiment as shown in FIG. 2; however, in this case a 40% step increase was applied to the feed addition rate.
FIG. 4 is a simplified flow chart of a typical feed rate control algorithm, using the electrical conductance signal, that was used in the experiment represented in FIG. 5.
FIG. 5 is the representation of some parameters in an experiment during which the exponential factor K was set at 0.12 h -1 which is higher than the usual value of 0.07 h -1 for this yeast strain. During the experiment the algorithm using the conductance signal, of which the flow chart is shown in FIG. 4, was active.
FIG. 6 shows some parameters of an experiment with the bacterial strain E. coli DH5α in which the conductance control algorithm shown in FIG. 4 was active. The factor K was set at 0.4 h -1 in this experiment. Normally a factor 0.11 h -1 would be used (Riesenberg et al., 1991).
FIG. 7 shows some parameters of an experiment with the bacterial strain E. coli DH5α in which the feed rate was manually increased in three steps (21.3-22.3 h) and then was controlled by a similar algorithm as described in FIG. 4 but modified as described in Example 5.
FIG. 8 is a schematic representation of a fermenter suitable for use in the process of the invention.
EXAMPLE 1
The Electrical Conductance During a Normal Fed-Batch Fermentation
In order to determine the normal trend of the electrical conductance during a fed-batch fermentation (FIG. 1), we monitored the conductance on a fermentation control computer linked to an Aber Instruments (Aberystwyth, UK) Biomass Monitor 214A with an Aber Instruments Capacitance probe. The conductance signal was noisy due to the aeration of the fermenter. Therefore, the conductance had to be electrically filtered using the supplied filter number 2 on the Biomass Monitor 214A. As an alternative other conductivity probes and monitors can be used as long as the signal is adequately filtered to smooth the noisy signal. One such set up can be a Broadley James conductivity probe (from FT Applikon) linked to an MCD43 monitor (LTH Electronics) which uses a 3 min filter. All data in FIG. 1 are averaged over 10 min (due to the data storage limitations of the fermentation control computer).
The fermentation was performed as described by Clarke et al (1990), which is incorporated by reference. Essentially, the fermentation was as follows.
The fermentation was based on yeast transformed to express recombinant human albumin (rHA). The cloning strategy for construction of the yeast was as disclosed in EP 431 880.
A stock master cell culture in defined liquid medium (Buffered Minimal Medium (BMM) salts medium: Yeast Nitrogen Base [without amino acids and (NH 4 ) 2 SO 4 , Difco], 1.7 g/L; citric acid monohydrate 6.09 g/L; anhydrous Na 2 HPO 4 , 20.16 g/L; pH 6.5±0.2; (NH 4 ) 2 SO 4 , 5 g/L; sucrose is added to 20 g/L) was used to prepare running stocks (manufacturer's working cell bank) of process yeast suitable for the preparation of shake flask cultures by freezing aliquots of the culture in the presence of 20% (w/v) trehalose.
Shake Flask Culture. The yeast [cir°, pAYE316] was grown as an axenic culture physiologically suited for inoculation of the seed vessel. If timing of the seed vessel is to be reproducible, it is necessary to define the phase of growth (primary carbohydrate excess) and inoculum biomass (12±2 mg/L which requires a 100 ml inoculum per 10 liters of medium). One stock vial was inoculated into a shake flask containing 100 mL of BMM+2% (w/v) sucrose and the flask was incubated at 30° C. on an orbital shaker (200 rpm revolutions per minutes) until a cell dry weight (cdw) of 0.6-1.2 g/L (assessed by optical density at 600 nm) was obtained. This culture was then used to inoculate a seed fermentation vessel to a level of 12±2 mg/L.
Seed Fermentation. The inoculum for the main production fermenter was provided by growing the production organism, preferably S. cerevisiae [cir°, pAYE316], in a seed fermenter to a high cell dry weight of approx. 100 g/L. A fed-batch regime was followed so as to minimise the accumulation of ethanol and acetate and thus to maximise cell yield. The whole of each fermentation was monitored and controlled via a computer control system, such as the Multi-Fermenter Computer System (MFCS) software available from B. Braun (Germany). The software supplied by B. Braun is a Supervisory Control and Data Acquisition Package; similar packages are available from other companies. The algorithm is intended to control the addition of sucrose so that maximum biomass is achieved by avoiding the Crabtree effect, thereby minimising the production of ethanol and/or acetate. The fermentation vessel was subjected to a hot NaOH wash and pyrogen-free water (PFW) rinse. The heat sterilised vessel contained one volume of sterile MW10 nedium (Table 1) batch salts plus trace elements. An alternative medium is given in Table 2. Clearly, the initial conductivity will vary according to the constitution of the medium. The medium for rHA production can be ultrafiltered (10,000 Mol. Wt. cut-off) to remove endotoxins.
TABLE 1______________________________________MW10 MEDIUM______________________________________Constituents Batch Medium Feed Medium______________________________________ SaltsKH.sub.2 PO.sub.4 2.74 g/L 10.9 g/L MgSO.sub.4.7H.sub.2 O 0.58 g/L 2.3 g/L CaCl.sub.2.2H.sub.2 O 0.06 g/L 0.24 g/L H.sub.3 PO.sub.4 (85% w/w) 0.88 ml/L 1.76 ml/L Vitamins Ca pantothenate 20 mg/L 180 mg/L Nicotinic acid 33.3 mg/L 300 mg/L m-Inositol 20 mg/L 180 mg/L d-biotin 0.133 mg/L 0.8 mg/L Thiamine.HCl 16 mg/L 32 mg/L Trace element stock 10 ml/L 20 ml/L Sucrose 0* 500 g/L______________________________________ Trace Element Stock Constituents ZnSO.sub.4.7H.sub.2 O 3 g/L FeSO.sub.4.7H.sub.2 O 10 g/L MnSO.sub.4.4H.sub.2 O 3.2 g/L CuSO.sub.4.5H.sub.2 O 0.079 g/L H.sub.3 BO.sub.3 1.5 g/L KI 0.2 g/L Na.sub.2 MoO.sub.4.2H.sub.2 O 0.5 g/L CoCl.sub.2.6H.sub.2 O 0.56 g/L______________________________________ The trace elements were added to demineralised water, acidified with 35 ml/L of 98% H.sub.2 SO.sub.4. *20 g Sucrose/L was added to the batch medium at the 20 L seed fermenter stage. Any convenient method of sterilisation may be used, as may any depyrogenation method, for example ultrafiltration. The vitamins were always filter sterilised.
TABLE 2______________________________________MW11D MEDIUM______________________________________Constituents Batch Medium Feed Medium______________________________________ SaltsKH.sub.2 PO.sub.4 4.66 g/L 9.54 g/L MgSO.sub.4.7H.sub.2 O 0.98 g/L 2.02 g/L CaCl.sub.2.2H.sub.2 O 0.10 g/L 0.21 g/L H.sub.3 PO.sub.4 (85% w/w) 1.63 g/L 3.33 g/L Vitamins Ca pantothenate 68 mg/L 140 mg/L Nicotinic acid 114 mg/L 233 mg/L m-Inositol 68 mg/L 140 mg/L d-biotin 0.34 mg/L 0.70 mg/L Thiamine.HCl 17.1 mg/L 35 mg/L Trace element stock 10.2 mL/L 21 mL/L Sucrose 0* 500 g/L______________________________________ Trace Element Stock Constituents ZnSO.sub.4.7H.sub.2 O 3 g/L FeSO.sub.4.7H.sub.2 O 10 g/L MnSO.sub.4.4H.sub.2 O 3.2 g/L CuSO.sub.4.5H.sub.2 O 0.079 g/L Na.sub.2 MoO.sub.4.5H.sub.2 O 0.5 g/L CoCl.sub.2.6H.sub.2 O 0.56 g/L______________________________________ The trace elements were added to demineralised water, acidified with 35 ml/L of 98% H.sub.2 SO.sub.4. *20 g Sucrose/L was added to the batch medium at the 20 L seed fermenter stage. Any convenient method of sterilisation may be used, as may any depyrogenation method, for example ultrafiltration. The vitamins were always filter sterilised. After the medium was added to the vessel, the operating temperature of 30° C. was set, as well as the minimum stirrer speed, typically 400-500 rpm. The initial pH was adjusted with ammonia solution (specific gravity 0.901) using a pH controller set at 5.7 ± 0.2. 2M H.sub.2 SO.sub.4 was also used as a pH corrective agent. Sucrose to 20 g/L, MW10 batch vitamins, and Breox FMT30 antifoam to 0.04 g/L are added to the vessel.
Sterile filtered air was introduced into the vessel at 0.5 vvm (ie 0.5 liter non-compressed air per liter of medium per minute), the medium was inoculated to 12±2 mg cell dry weight L -1 from an axenic shake flask culture and the MFCS computer system was initiated. Following completion of the batch phase of growth (signalled by a dissolved oxygen tension increase of >15% in 30 min), addition of the feed medium was initiated, under control of the MFCS system. The control strategy was effectively the same as described below for the production fermenter. During the fermentation the airflow was increased in two steps in order to maintain a flow of approximately 1 vvm. Further Breox FMT30 was added to a final concentration of 0.3 g/L. The dissolved oxygen tension (DOT) was controlled at 20% air saturation by changing the stirrer speed. Once the stirrer speed could be increased further and the airflow rate reached its maximum value, the feed control algorithm (see below) controlled the feed rate such that the DOT did not decrease below 15% in order to prevent oxygen limited conditions that, otherwise, would lead to formation of fermentation products.
Also RQ was used as a feedback for the feed addition control. The feed rate was reduced every 10 min while RQ≧1.2. Moreover, a 120 min RQ average (RQAVG 120 ) was calculated to filter the noisy RQ signal (Goodey el al, 1996). The feed rate was reduced once every two hours by 20% if the value of RQAVG 120 ≧1.13. Due to an expected high RQ value at the start of a fermentation this RQAVG 120 control was not performed during the first 4 hours of the feed addition phase. At the end of the feed, the culture was transferred to a production vessel.
Production Fermentation. The production fermenter (FIG. 8) was inoculated with the culture grown in the seed fermenter (see above). The cell dry weight (CDW) concentration in the seed fermenter was normally greater than 80 g/L. The CDW concentration in the production fermenter just upon transfer of the seed fermenter culture was 0.25-1.00 g/L. Although it is preferred to initiate feeding within one hour, it can be delayed if necessary. The feed regime was intended to minimise the accumulation of ethanol and acetate, so as to maximise the cell and product yield.
The fermentation was carried out in a fermenter such as that shown in FIG. 8, designed to give optimum gas dissolution and bulk mixing. The fermenter was equipped with ports for, amongst other things, supplying feed medium, withdrawing medium at the end of the fermentation and introducing a probe for measuring electrical conductance. The vessel, which was subjected to a hot NaOH wash and PFW rinse, contained one volume of sterile MW10 (Table 1), batch salts and trace elements. This medium may be sterilized independently of the vessel either by heat or filter sterilisation. It has been found in accordance with the present invention that it is advantageous for the fermentation medium, such as MW10, to be free of ethylene diamine tetraacetic acid (EDTA), or a salt thereof, since its presence results in a significantly higher degree of coloured contaminants in the albumin produced.
The operating temperature was set at 30° C., and the stirrer speed regulated to be sufficient to maintain a homogeneous solution, typically about 50 rpm. The initial pH was adjusted with ammonia solution (SG 0.901) (controller set to 5.7±0.2). 2M H 2 SO 4 nay be used as a second pH corrective agent. The MW10 batch vitamins were added, as was a suitable antifoam, as required (eg Breox FMT30 to 0.4 g/L). When the feed is started, the RQ over-ride control was disabled until OUR and CER values are sufficiently high to make control effective; the feed rate was reduced manually during this period if RQ was consistently >1.2.
The pH of the culture was kept constant at 5.5 by automatic addition of 17% (w/v) ammonia. The temperature was kept at 30° C. Sterile airflow was introduced at 0.5 vvm. During the fermentation the airflow was increased in three steps in order to maintain a flow of approximately 1 vvm. This was measured by a continuous mass spectrometric analysis (Fisons VG Gas analyser). The fermentation was then run as above. Also the pressure in the fermenter was increased during the fermentation to approximately 0.5 bar g by using a Brooks pressure controller.
The feed rate was started at a feed rate, FR start , that was necessary to achieve a growth rate of approximately 0.07 h -1 . Then the feed rate was increased, by computer control, according to the algorithm:
FR=FR.sub.start EXP(K*Counter)
Where:
FR: feed rate (ml.min -1 )
K: the exponential constant which was kept at 0.07
Counter: a counter variable started at 0 and was increased by 0.0167 once every min. However, the counter variable was decreased:
a. by 0.0167 once every min if the dissolved oxygen tension (DOT) was less than 15%.
b. by 0.333 once very 10 min while RQ≧1.2.
c. by 0.223/K (resulting in a 20% feed rate reduction) once every two hours while RQAVG 120 ≧1.13 if the feed addition was started more than 4 h ago.
The result of such a fermentation is shown in FIG. 1. It can be concluded that the conductance trend in general sloped downwards during the course of the fed-batch fermentation.
EXAMPLE 2
The Electrical Conductance During a Phase where the Feed Rate was Suddenly Increased by 20%
In order to establish the use of the conductance signal in the prevention and correction of acetate accumulation, a deliberate sudden step-increase of feed rate of 20% was applied at some stage in a carbon-limited fed-batch fermentation similar to the one described in Example 1. The results are shown in FIG. 2. It is shown that the conductance increased significantly during the period where the over-feed was applied. In fact, the RQ, a parameter often used in the control of Bakers' yeast production, did not show a significant increase. This shows the usefulness of the conductance signal because acetate production is undesirable during Bakers' yeast production. The increase in conductance correlated with an increase in acetate concentration in the culture as assayed in culture samples. The acetate was assayed using an enzymatic assay kit No. 148 261 from Boehringer Mannheim.
EXAMPLE 3
The Electrical Conductance During a Phase where the Feed Rate was Suddenly Increased by 40%
In a similar experiment as shown in Example 2 a sudden 40% feed rate increase was applied (see FIG. 3). The effects were more extreme than in Example 2, as would be expected. Also the RQ increased. However, a value of 1.2, which typically is used as a level to instigate feed rate reductions (see Example 2), was not reached. This again shows that conductance is a more sensitive physical control parameter than RQ.
EXAMPLE 4
The Use of a Feed Rate Control Algorithm Incorporating Electrical Conductance
In FIG. 4 a flow diagram is shown representing the feed addition control algorithm that was used in this Example. The basis was the normal control algorithm as shown in Example 1. The condition where an airflow or pressure set point increase prevents the conductance feed control to be applied for 1 hour was necessary due to the fact that airflow and pressure increases will result in a small increase in conductance due to changes in gas holdup volume.
Moreover, in comparison with Example 1 the following additions were made to the feed rate control algorithm. The change in conductance (ΔC in mS) was measured over a time interval of 30 min. If the feed had been started within the last 1.5 h no feed back control would result. However, after that, in cases where the increase ΔC was ≧0.1 mS over the chosen time interval, an automatic feed rate reduction would result. The actual size of the feed rate reduction was made dependent on the actual value of ΔC as follows: FR reduced =F original *(1-ΔC). No feed rate reduction would be applied if RQ≦0.95 or if the difference in RQ 30 (RQ averaged over 30 min) over a time interval of 20 min: RQ 30 -RQ 30 20 min ago ←0.025. Both these conditions indicate that the yeasts were already co-metabolising the feed substrate and fermentation products, thus abolishing the need for feed rate reductions.
An experiment was carried out where the exponential constant K (see Example 1) was set to 0.12 h -1 which is so high that production fermentation products would be expected for this yeast strain which was the same as in Example 1. This was done to test the action of the control algorithm as shown in FIG. 4 and explained above. The results are presented in FIG. 5. The Figure shows a steady increase of conductance correlating with an increase in the acetate concentration. At 2.3 h (batch age) an automatic feed rate reduction was applied. This, however, was not sufficient and another automatic feed rate reduction was applied at 4.5 h (batch age). After that the acetate concentration reduced to 0 mM. Then the acetate concentration increased temporarily at batch age 5 h, whilst the conductance was decreasing. At the same time an excess of ammonium ions, which will have been added in the period up to 4.5 h (batch age) for pH control, was probably being consumed as judged by the pH changes in the culture. It is known that ammonium ions conduct electricity better than acetate ions (Owens, 1985) which explains the overall decrease of the conductance signal. Again a small peak in acetate concentration occurred at batch age 6 h. In this case the conductance increase was not enough to invoke a feed rate reduction. However, as judged by the reduction of the acetate concentration after that, further feed rate reductions were not necessary.
EXAMPLE 5
The Use of a Feed Rate Control Algorithm Incorporating Electrical Conductance with the Bacterial Strain E. coli
The bacterial strain Escherichia coli DH5α was grown in a fermenter using the medium described by Riesenberg et al (1991). The same control algorithm was used as in Example 4. However, the factor K was set at 0.4 h -1 . In FIG. 6 the result of the action of the control algorithm is illustrated. After a build up of acetate two automatic feed rate reductions resulted in a decrease of acetate from 45 to 5 mM.
This artificially high challenge to the fermentation showed that the system would work even under extreme conditions.
EXAMPLE 6
A Further E. coli Fermentation
This represents a more realistic (but still artificial) challenge to the equilibrium of a fermentation.
The bacterial strain E. coli DH5α was grown in a fermenter using the medium described by Riesenberg et al (1991). A similar control was used as in Example 4. However, the factor K was set at 0.1 h -1 . This would, under normal aerobic conditions, not lead to the production of organic anions. Then between the batch age 21.3-22.3 h (see FIG. 7) the feed rate was increased manually in three steps. Following this intervention, the conductivity increased and the feed rate was controlled according to the algorithm described in FIG. 4 with the following modifications. A control step was taken once every 10 min (as the conductivity increase was very steep) but the size of the feed rate reduction was a quarter of that described in FIG. 4. Thus the formula for feed rate was FR reduced =FR original (1-ΔC/4). As shown in FIG. 7 this controlled the fermentation such that the acetate produced was consumed by the cells. This example shows that the control algorithms may be optimised for different situations such as different organisms, growth rate and media types.
"Breox" is a trademark.
REFERENCES
Belfares et al (1993) Bioprocess Eng. 9, 197-204.
Clarke P. M., Collins S. H. and Mead D. J. (1990) "Fermentation of genetically engineered yeast in the presence of polyalkylene compound" WO 90/02808.
De Deken R. H. (1966) "The Crabtree effect: a regulatory system in yeast" J. Gen. Microbiol. 44, 149-156.
Doelle W. (1981) "New developments in the elucidation of the mechanisms of the Pasteur and Crabtree effects in bacteria" In: Moo-Young M., Robinson C. W. and Vezina C. (Eds.), Advances in Biotechnology, Pergamon Press, Vol. 1, pp 249-254.
Fiechter A., Fuhrmann G. F. and Kappeli O. (1981) "Regulation of glucose metabolism in growing yeast cells" Adv. Microbiol. Physiol. 22, 123-183.
Goodey A. R., Sleep D., van Urk, H., Berezenko S., Woodrow J. R. and Johnson, R. A. (1996). Process of high purity albumin production. International Patent Application. Publication No. WO 96/37515.
Latrille E., Picque D., Perret B. and Corrieu G. (1992) "Characterizing acidification kinetics by measuring pH and electrical conductivity in batch thermophilic lactic fermentations" J. Ferment. Bioeng. 74, 32-38.
Moon N. J. (1983) "Inhibition of the growth of acid tolerant yeasts by acetate, lactate and propionate and their synergistic mixtures" J. Appl. Bacteriol. 55, 453-460.
Owens J. D. (1985). Formulation of culture media for conductimetric assays: Theoretical considerations. J. Gen. Microbiol. 131: 3055-3076.
Pampulha M. E. and Loureiro-Dias M. C. (1989) "Combined effect of acetic acid, pH and ethanol on intracellular pH of fermenting yeast" Appl. Microbiol. Biotechnol. 31, 547-550.
Riesenberg D., Schulz V., Knorre W. A., Pohl H.-D., Korz D., Sanders E. A., Ross A. and Deckwer W.-D. (1991). High cell density cultivation of Escherichia coli at controlled specific growth rate. J. Biotechnol. 20: 17-28.
Sakamoto et al (1994) J. Ferment. Bioeng. 78, 304-309.
Soyez K., Schultz E. and Prause M. (1983) "Verfahren zur Steuerung der Kultivierung von Mikroorganismen" German Patent (DDR) 200894/2.
Turner C., Gregory M. E. and Thornhill N. F. (1994) "Closed-loop control of fed-batch cultures of recombinant E. coli using on-line HPLC" Biotechnol. Bioeng. 44, 819-829.
Wang H. Y., Cooney C. L. and Wang D. I. C. (1977) "Computer-aided Bakers' yeast fermentations" Biotechnol. Bioeng. 19, 69-86.
|
A process of culturing a microorganism in a culture medium in which process the addition of feed medium is controlled by using the production of a by-product as a measure of the culture conditions, characterized in that the by-product is an electrically charged metabolite produced by the microorganism, and in that the production of the metabolite is monitored by measuring the conductance of the culture medium. The metabolite may be acetate and the microorganism may be yeast which is genetically engineered to produce a desired polypeptide.
| 2
|
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an image projector, more particularly to an image projector with optical valves such as liquid-crystal valves, which is used to display a computer or video image on an external screen.
[0002] One example of an image projector using liquid-crystal optical valves is shown in FIG. 1. This projector comprises an illumination system 1 having a lamp 10 , such as a metal halide, xenon or similar lamp, and a reflector 11 surrounding the lamp 10 . The illumination system 10 is combined with an optical integrator 2 , the role of which is to uniformly distribute the light emitted by the lamp 10 of the illumination system, over the components of the optical unit 3 which will be described hereinafter. The optical unit 3 has, schematically, colour separation means so as to supply each optical valve 30 , 31 , 32 with the corresponding colour component and a means 20 of recombining the images supplied by the three optical valves. As shown in FIG. 1, the image recombination means is formed by a cube 20 constituting a set of mirrors 22 and 24 occupying the diagonal planes of the cube 20 . The three liquid-crystal valves 30 , 31 , 32 are placed parallel to three faces of the cube. More accurately, the optical valve 30 is parallel to the face 26 of the cube. The optical valve 32 is parallel to the opposite face 28 of the cube, the two valves 30 and 32 being parallel to each other and the optical valve 31 is parallel to the face 27 of the cube and perpendicular to the other two valves 30 and 32 .
[0003] As the illumination system 1 emits white light, colour separation means are therefore provided in the optical system 3 . These means are formed by dichroic mirrors combined with plane mirrors in order to direct, respectively, the blue colour component onto the optical valve 30 , the green colour component onto the optical valve 31 and the red colour component onto the optical valve 32 . More specifically, the light emitted by the illumination system 1 passes through a first dichroic mirror 33 placed immediately downstream of the integrator 2 . The normal N to the plane of the mirror 33 forms an angle of 45° with the optical axis O. Because of this, the dichroic mirror 33 transmits the blue colour component to a plane mirror 34 positioned so as to illuminate the optical valve 30 via a field lens 40 and reflects the remainder of the spectrum towards a second dichroic mirror 35 parallel to the first dichroic mirror 33 . This second dichroic mirror 35 reflects the green colour component of the spectrum towards the optical valve 31 through a field lens 41 similar to the lens 40 . The dichroic mirror 35 transmits the remainder of the spectrum, i.e. the red colour component. This red component passes through a first lens 42 then is reflected by a plane mirror 36 parallel to the dichroic mirrors 38 and 40 . The component reflected by the plane mirror 36 passes through a lens 44 then is reflected again by a plane mirror 37 in such as way as to be sent back to the optical valve 32 through a field lens 43 identical to the lenses 40 and 41 . The images formed on the optical valves 30 , 31 and 32 are then recombined by reflection and transmission inside the cube 20 so as to obtain a synthetic image on the face 29 of the cube, this image being sent to a projection lens 5 .
[0004] The apparatus described with reference to FIG. 1 comprises numerous components, especially optical and electronic components, which have to operate in a clean environment and at acceptable temperature levels. Now, in order to obtain good quality images having a high luminosity, it is generally necessary to use powerful projection lamps. The use of bright lamps which are more and more powerful makes the thermal aspects more critical within the projector. This leads to the use of more and more elaborate cooling systems which must also take into account parameters such as the increase in the resolution of the optical valves, the desire to have the minimum overall size, the noise level of ventilation systems and the increase in the functions offered.
SUMMARY OF THE INVENTION
[0005] The object of the present invention is therefore to provide an image projector with an improved cooling system which especially enables the following advantages to be obtained, viz.:
[0006] to ensure that all the critical parts are kept below their limit temperature;
[0007] to allow the proper operation of the projector up to ambient temperatures which may reach 50° C.;
[0008] to ensure the system is placed away from dust and to minimize as far as possible the noise level.
[0009] As a consequence, the subject of the present invention is an image projector comprising a casing containing at least:
[0010] an illumination system;
[0011] an optical unit comprising at least one optical valve modulating the light emitted by the illumination system;
[0012] a projection lens projecting the modulated light outside the casing;
[0013] a power supply, control electronics and cooling means;
[0014] the casing being provided with at least one aperture forming an air inlet,
[0015] characterized in that it further comprises a specific air filtration means positioned under the optical unit and in such a way as to surround the latter.
[0016] According to a preferred embodiment, the air filtration means is a component in the shape of a cage, the side walls of which are covered with wire mesh.
[0017] Preferably, the present invention is applicable to a colour image projector the optical unit of which comprises three optical valves each provided for one colour, colour separation means to supply each optical valve with the corresponding colour component from the light emitted by the illumination system and a means of recombining images supplied by the three optical valves.
[0018] According to another characteristic of the present invention, the projector further comprises at least one cooling means for the optical valve or valves. Preferably, it comprises three turbines positioned inside the specific air filtration means, under each optical valve respectively.
[0019] To obtain better cooling of the projector, it further comprises a cooling means for the illumination system formed by a turbine positioned horizontally close to the illumination system, this turbine being extended by two air guides, a first air guide sending part of the air to the illumination system and a second air guide sending the other part of the air to the optical unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Moreover, the projector may comprise additional cooling means and air extraction means generally formed by fans.
[0021] According to an additional characteristic of the present invention, the speed of the turbines and of the fans is variable according to the temperature, the temperature being detected by at least one thermistor combined with an electrical control circuit for each fan.
[0022] Moreover, according to yet another characteristic of the present invention, the casing has an aperture forming an air inlet on each side face and at least one air extraction aperture on the rear face.
[0023] Other characteristics and advantages of the present invention will become apparent on reading the description of a preferred embodiment, this description being given with reference to the appended drawings in which:
[0024] [0024]FIG. 1, already described, is a schematic representation of the essential components of a projector which may be used with the present invention.
[0025] [0025]FIG. 2 is an exploded schematic perspective view of a casing according to the present invention used for a projector of the type shown in FIG. 1.
[0026] [0026]FIGS. 3A and 3B are schematic top views of the upper part and the lower part respectively of the projector, showing the positioning of the specific filtration and cooling means used in the present invention.
[0027] [0027]FIG. 4 is a partial perspective view of the specific air filtration means used in the present invention.
[0028] [0028]FIG. 5 is a schematic top view showing the position of the three turbines used to cool the optical valves.
[0029] [0029]FIG. 6 is a lateral sectional view of the cooling means of the illumination system.
[0030] [0030]FIG. 7 is a circuit diagram showing the control box for the turbines and fans used in the present invention, and
[0031] [0031]FIG. 8 is a perspective view of part of the front face used in the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] In order to simplify the description, the same components bear the same reference numbers in the figures.
[0033] [0033]FIG. 2 shows a perspective view of a casing which may contain the components of the projector of FIG. 1. As this casing has a substantially parallelepipedal shape, it comprises an upper part or lid 100 which has a cross section in the shape of a U. The lid therefore has a top plate 102 and two side panels 103 , 104 provided in their lower part with a support rod 105 .
[0034] As shown in FIG. 2, the side plates 103 and 104 are each provided with an oblong window 106 forming an air inlet. This window 106 is closed by a first filtration means made up of an EMC mesh complying with electromagnetic standards, of a non-inflammable foam and of a metal gauze having 160 μm apertures, for example. The upper plate 102 has been pressed in its central part to enable the various components to be housed. Moreover, the upper lid 100 has in its rear part two plates 107 a and 107 b which snap-fasten on the lower frame, as explained below. Between the two plates 107 a and 107 b an aperture 108 is provided, which enables the air used for the ventilation of the projector components to be extracted. As shown in FIG. 2, the casing therefore comprises a lower part 101 provided with a frame formed by a rectangular plate 109 on which the front face 110 is mounted and fastened onto the frame via brackets 111 . The front face 110 has a circular or oblong aperture 112 for the projection lens to pass through, as will be explained below and a control panel 113 provided with buttons (not shown). On the rear part of the frame 109 two housings 113 and 114 in the shape of an angle bracket are also provided, against which the plates 107 a and 107 b are snap-fastened. Moreover, according to the present invention, the plate 109 is hollowed out in its central part in order to receive a second filtration component which is positioned so as to surround the turbines cooling the optical unit 3 , as shown in FIGS. 3A and 3B. This specific filtration means 115 will be described and shown in more detail in FIG. 4. It comprises a base plate 1150 which is fastened via any known means such as screws passing through the holes 1151 , to the plate 109 forming the frame. This type of fastening enables the filtration means 115 to be removed by extracting it through the bottom of the casing for the purpose of cleaning it. Another plate 1152 , intended to receive the actual filtration components, is mounted on the plate 1150 . The filtration component is made, for example, of a metal gauze 1153 having 80 μm apertures. The gauze rests against four lugs 1154 provided at the four corners of the plate 1152 , and which lugs are secured via U-shaped brackets 1155 a , 1155 b , as shown in FIG. 4. The front face of the filtration means is sealed with an impermeable fabric 1156 . The use of this second filtration means positioned under the sensitive components such as the liquid-crystal optical valves means that the region most sensitive to dust can be kept in a very clean environment.
[0035] According to another characteristic of the present invention and as shown in FIGS. 3A, 3B and 5 , a specific cooling means, viz. one of the turbines 116 , 117 , 118 , is associated with each liquid-crystal valve 30 ′, 31 ′, 32 ′ surrounding the cube 20 . As clearly shown in FIG. 5, the turbines are positioned vertically under each liquid-crystal valve so that the air exiting the turbine arrives at the active surface of the liquid-crystal valves, as symbolized by the arrows.
[0036] The other essential components of the projector, viz. the illumination system comprising a lamp 10 and a reflector 11 , an integrator 2 and a set of dichroic mirrors and of plane mirrors similar to those described with reference to FIG. 1 for sending the blue, green and red colour components to the liquid-crystal valves 30 ′, 31 ′ and 32 ′, respectively, are positioned in the upper part of the casing, as shown in FIG. 3B.
[0037] According to another characteristic of the present invention, an additional turbine 119 is provided inside the casing containing the projector components. This turbine 119 is positioned horizontally in the lower part of the casing, as shown in FIG. 3B. As shown in FIG. 6, this turbine 119 opens out into an air guide which is in two parts 120 , 121 . The first air guide 120 directs the air blown by the turbine 119 onto the illumination system 1 , most particularly at the edge of the reflector 11 . The air guide 121 directs the air blown by the fan 119 onto the components of the optical unit 3 . Preferably, two-thirds of the air blown by the turbine 119 are sent to the illumination system 1 , the remaining third being sent to the optical unit 3 .
[0038] Moreover, as shown schematically in FIGS. 3A and 3B, two axial fans 140 and 141 are provided in the rear part of the casing, one of the fans being used to extract air from the casing, the other being used to cool the ballast of the control circuit. The other hatched parts of FIGS. 3A and 3B show the location of the power supplies and of the signal receiving cards.
[0039] According to an additional characteristic of the present invention, and as shown in FIG. 7, the various turbines 116 , 117 , 118 , 119 and fans 140 , 141 are controlled so as to have a speed which can be varied according to temperature. As a result, the control circuit for the fans and the turbines is associated with at least one thermistor. As shown in FIG. 7, the circuit comprises a transistor T mounted in the collector-follower configuration. In the embodiment shown, the source of the transistor is connected to 5 resistance bridges mounted in parallel. Each bridge is formed by two resistors R and R′ connected in series between the source of the transistor T and earth. A connector C, intended to receive the power intakes for the fans and turbines, is mounted at the common point A between the 2 resistors R and R′. The thermistor is mounted on a connector C 1 provided between earth and a point B. The point B is connected through a resistor R 1 to the emitter of the transistor T and through a resistor R 2 to the power-supply connector C 2 which is also connected to the collector of the transistor T. A capacitor Ca is mounted in parallel between the power supply and earth. This circuit enables the various fans and turbines to be supplied with power. The resistors R and R′ do not necessarily have the same values from one bridge to the other and have values which can be varied according to the power demanded by the fans and turbines. An additional connector C 3 for the lamp ballast is mounted between earth and the power supply C 2 .
[0040] Moreover, as shown in FIG. 8, the projection lens 5 is generally mounted so that it can be offset upwards or downwards in order to offset the projected image. Because of this, the lens passes through an oblong aperture 112 made in the front face of the casing. However, in order to avoid dust getting in, the projection lens 5 may be mounted on a system such as shown in FIG. 8, viz. the projection lens is sealed onto a plate 130 , which in turn is fastened via a bellows system 131 a , 131 b to the frame 109 and to an upper plate 132 , respectively, which snap-fastens under the upper part 102 of the lid 100 . This bellows system 131 a , 131 b therefore means that the projection lens 5 can be moved while remaining sealed.
[0041] It is obvious to those skilled in the art that the system described above can be modified in numerous ways without departing from the claims below, especially with regard to the positioning of the turbines and of the fans, the materials used, the location of the apertures forming air inlets or for air extraction, etc.
|
The present invention relates to an image projector comprising a casing containing at least:
an illumination system ( 11, 10 );
an optical unit comprising at least one optical valve ( 30′, 31′, 32′, 20 ) modulating the light emitted by the illumination system;
a projection lens ( 5 ) projecting the modulated light outside the casing;
a power supply, control electronics and cooling means ( 116, 117, 118, 119, 140, 141 );
the casing being provided with at least one aperture ( 106 ) forming an air inlet. The casing further comprises a specific air filtration means ( 115 ) positioned under the optical unit and in such a way as to surround the latter.
The invention is mainly applicable to LCD projectors.
| 6
|
FIELD OF THE INVENTION
The present invention relates generally to a method for controlling electromechanical valves in an internal combustion engine with direct fuel injection.
BACKGROUND OF THE INVENTION
An electromechanically operated poppet valve in the cylinder head of an internal combustion, as disclosed in U.S. Pat. No. 4,455,543, is actuated by energizing and de-energizing electromagnets acting upon an armature coupled to the poppet valve. Because the actuation of the electromagnets is controlled by an electronic control unit, valve opening and closing events occur independently of engine rotation. In conventional engines with camshaft actuated valves, which have timings based on engine rotation, air delivery to the cylinders is controlled by a throttle valve placed in the inlet duct of the engine. In contrast, electromechanical valves are capable of controlling air delivery based on valve timing, thereby providing a thermal efficiency improvement over throttled operation of a conventional engine.
However, a drawback to electromechanical valves, particularly at low torque, is the undesirable noise generated when the valves impact upon opening and closing. Furthermore, because there is no throttling, or less throttling, the incoming air through the valves has very little turbulence. The ensuing combustion wave propagates very slowly through the relatively quiescent mixture, leading to combustion instability and rough operation. Furthermore, fuel-air mixing, particularly in engines with direct fuel injection, is insufficient at low turbulence levels.
SUMMARY OF THE INVENTION
Disadvantages of prior methods are overcome by a method for operating an internal combustion engine, the engine having a plurality of engine cylinders with reciprocating pistons. Each cylinder has an electromechanically-actuated intake valve, an exhaust valve, and a fuel injector disposed in a cylinder head of the engine. The engine also has an electromechanical valve system with: an armature connected to the intake valve, a valve closing electromagnet capable of exhibiting an electromagnetic force for attracting the armature to open the intake valve, a valve opening spring for biasing the armature in a direction to open the intake valve, and a valve closing spring for biasing the armature in a direction to close the intake valve. The method includes de-energizing the valve closing electromagnet associated with a particular cylinder during an intake stroke such that the intake valve is fully open when a speed of the piston within the particular cylinder is near a maximum; opening the fuel injector so that fuel sprays into the particular cylinder during peak flow rate through the intake valve; and energizing the valve closing electromagnet after a predetermined time has elapsed.
Also disclosed is an internal combustion engine with a plurality of cylinders. The engine has an electromagnetically-actuated intake valve disposed in each cylinder, a piston in each cylinder, an armature operatively connected to said intake valve, a valve closing electromagnet capable of exhibiting an electromagnetic force for attracting the armature to close the intake valve, a valve opening spring coupled to the armature for biasing the armature in a direction to open the intake valve, and a valve closing spring coupled to the armature for biasing the intake valve to a closed position. The engine is coupled to an electronic control until which is further coupled to the valve closing electromagnet. The electronic control unit de-energizes the valve closing electromagnet in a particular cylinder during an intake stroke in the particular cylinder. The electronic control unit energizes the valve closing electromagnet. The time of de-energizing is such that the intake valve is fully open near a time of a maximum speed of the piston in the particular cylinder.
An advantage of the present invention is that the valve is opened at such a time in the intake stroke to provide a high degree of turbulence to the intake gases in the cylinder. The higher turbulence increases the combustion rate
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages described herein will be more fully understood by reading an example of an embodiment in which the invention is used to advantage, referred to herein as the Detailed Description, with reference to the drawings wherein:
FIG. 1 is a schematic of an engine equipped with electromechanically-actuated poppet valves;
FIG. 2 is a detail of an example of an electromechanically-actuated poppet valve in a closed position;
FIG. 3 is a detail of an example of an electromechanically-actuated poppet valve in an open position;
FIG. 4 a is a graph of valve position for an electromechanically actuated poppet valve operated using both the valve closing electromagnet and the valve opening electromagnet;
FIG. 4 b is a graph of valve position for an electromechanically actuated poppet valve operated using only the valve closing electromagnet;
FIG. 5 a is a graph of piston position as a function of crank angle degree;
FIG. 5 b is a graph of piston speed as a function of crank angle degree; and
FIG. 6 is a flowchart showing a method of operating the intake valve and fuel injector according to an aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 , a single cylinder 13 of an internal combustion engine 10 with an electromechanical intake valve 20 and exhaust valve 19 is shown. Engine 10 contains a piston 14 which reciprocates within cylinder 13 . Intake valve 20 , disposed in cylinder head 22 , is opened to allow gases to communicate between the combustion chamber (the volume enclosed by cylinder 13 , piston 14 , and cylinder head 22 ) and intake port 70 . When exhaust valve 19 is opened, gases are released from the combustion chamber into exhaust port 72 . In the embodiment shown in FIG. 1 , fuel is injected into the combustion chamber by injector 16 , a configuration commonly called direct fuel injection. Intake valve 20 and exhaust valve 19 are actuated electromechanically by valve actuators 18 and 17 , respectively. In a preferred embodiment, engine 10 is a spark-ignited engine, spark plug 12 initiates combustion in the combustion chamber. The present invention also applies to engines with other types of igniters and to compression ignition engines in which the fuel and air spontaneously ignite due to a compression-generated temperature rise in the combustion chamber. Both diesel and homogeneous charge compression ignition are examples of the latter type of engine.
Continuing to refer to FIG. 1 , electronic control unit (ECU) 60 is provided to control engine 10 . ECU 60 has a microprocessor 46 , called a central processing unit (CPU), in communication with memory management unit (MMU) 48 . MMU 48 controls the movement of data among the various computer readable storage media and communicates data to and from CPU 46 . The computer readable storage media preferably include volatile and nonvolatile storage in read-only memory (ROM) 50 , random-access memory (RAM) 54 , and keep-alive memory (KAM) 52 , for example. KAM 52 may be used to store various operating variables while CPU 46 is powered down. The computer-readable storage media may be implemented using any of a number of known memory devices such as PROMs (programmable read-only memory), EPROMs (electrically PROM), EEPROMs (electrically erasable PROM), flash memory, or any other electric, magnetic, optical, or combination memory devices capable of storing data, some of which represent executable instructions, used by CPU 46 in controlling the engine or vehicle into which the engine is mounted. The computer-readable storage media may also include floppy disks, CD-ROMs, hard disks, and the like. CPU 46 communicates with various sensors and actuators via an input/output (I/O) interface 44 . Examples of items that are actuated under control by CPU 46 , through I/O interface 44 , are fuel injection timing, fuel injection rate, fuel injection duration, throttle valve position, spark plug 12 timing, actuation of valve actuators 18 and 17 to control opening and closing of intake valve 20 and exhaust valve 19 , respectively, and others. Sensors 42 communicating input through I/O interface 44 may be indicating piston position, engine rotational speed, vehicle speed, coolant temperature, intake manifold pressure, pedal position, throttle valve position, air temperature, exhaust temperature, exhaust stoichiometry, exhaust component concentration, and air flow. Some ECU 60 architectures do not contain MMU 48 . If no MMU 48 is employed, CPU 46 manages data and connects directly to ROM 50 , RAM 54 , and KAM 52 . Of course, the present invention could utilize more than one CPU 46 to provide engine control and ECU 60 may contain multiple ROM 50 , RAM 54 , and KAM 52 coupled to MMU 48 or CPU 46 depending upon the particular application.
In FIG. 2 , an example of an electromechanical valve actuator 18 is shown in which intake valve 20 is in a closed position. Intake valve 20 closes off port 70 in cylinder head 22 . Valve actuator 18 is shown in detail in FIG. 2 . A valve closing spring 24 biases valve 20 to the closed position. Armature 30 is disposed between two electromagnets: a valve closing electromagnet 32 and valve opening electromagnet 28 . Armature 30 is connected to shafts 26 and 34 . As shown in FIG. 2 , armature 30 is next to valve closing electromagnet 32 . For this position to prevail, valve-closing electromagnet 32 is energized. Otherwise, armature 30 would act under the influence of valve closing spring 24 and valve opening spring 36 . In the embodiment shown in FIG. 2 , valve opening spring is attached to shaft 34 at the lower end of valve opening spring 36 . Other alternative configurations may also provide the same functionality, e.g., an electrohydraulic system. If both electromagnets 28 and 32 are de-energized, armature 30 is influenced by springs 24 and 36 and attains a neutral position in between electromagnets 28 and 34 . Valve actuator 17 and exhaust valve 19 can also be represented by FIG. 2 , by way of example.
Continuing to refer to FIG. 2 , valve actuator 18 preferably includes a valve position-sensing device, such as a linear variable differential transformer (LVDT) 38 . The tip of shaft 34 forms the core of the position sensor. The inductance of the LVDT varies when the position of the shaft 34 is altered with respect to the LVDT 38 windings. LVDT 38 is connected to ECU 60 (connection not shown). LVDT 38 is shown by way of example; other types of position sensing devices may also be used.
FIG. 3 shows the same hardware as shown in FIG. 2 with the difference being that FIG. 2 shows valve 20 in the fully closed position and FIG. 3 shows valve 20 in the fully open position. Thus, in FIG. 2 , valve closing electromagnet 32 is energized and, in FIG. 3 , valve opening electromagnet 28 is energized. In FIG. 2 , valve opening spring 36 is compressed. Holding current is applied to valve closing electromagnet 32 to act against the spring tension of valve opening spring 36 . Analogously, in FIG. 3 , valve closing spring 24 is compressed. Holding current is applied to valve opening electromagnet 28 to act against the spring tension of valve closing spring 24 .
Before discussing aspects of the present invention, an example of prior art control of an electromechanical valve is described. Typically, a valve, whether an intake or exhaust valve, of an internal combustion engine is normally closed, i.e., the valve is in the closed position for more of the time than the open position. Thus, the description of valve opening begins with a closed valve, i.e., with a holding current be applied to valve closing electromagnet 32 . Actuating the valve proceeds by: de-energizing valve closing electromagnet 32 which causes the valve to open under the influence of valve opening spring 36 ; applying a peak current to valve opening electromagnet 28 to grab armature 30 when it is near its fully open position; applying a holding current to valve opening electromagnet 28 after armature 30 is attracted to valve opening electromagnet 28 ); applying holding current for as long as the desired open duration of the valve; de-energizing valve opening electromagnet 28 which causes the valve to close under the influence of valve closing spring 24 ; and, applying a peak current to valve opening electromagnet 32 to grab armature 30 when it is near its fully closed position. The terms peak current and holding current are concepts known to those skilled in the art and refer to a higher current level (peak current) used to catch a moving armature 30 and a lesser current (holding current) used to prevent a stationary armature 30 from moving.
The neutral position, i.e., the position that valve 20 attains when both electromagnets 28 and 34 are de-energized, is about halfway between the fully closed position, FIG. 2 , and fully open position, FIG. 3 . The exact neutral position would depend, though, on the relative spring tensions of valve opening spring 36 and valve closing spring 24 .
The valve lift profiles for normal valve operation are shown in FIG. 4 a . The valve opens and is held open for a variable duration and then the valve is closed. Three example durations are shown in FIG. 4 a . The minimum duration is the sum of the opening time and the closing time and the maximum duration is infinite.
In FIG. 4 b , a plot of valve position as a function of time is shown for valve 20 under the situation that the valve at time T 0 is at the fully closed position by virtue of holding current being applied to valve closing electromagnet 32 . At time T 0 +, valve closing electromagnet 32 is de-energized. The valve lifts from the fully closed position and proceeds to a nearly open position by action of the valve opening spring 36 . As valve 20 progresses to a nearly open position, valve closing spring 24 becomes compressed. Valve 20 then returns to a nearly closed position under the influence of the valve closing spring 24 . The period of time that it takes for the valve to leave the fully closed position, travel to a nearly open position, and return to a nearly closed position is called a valve period and is indicated as T 1 in FIG. 4 b . The oscillation of valve 20 continues, with each successive peak and trough being closer to the neutral position than the prior peak or trough, due to irreversibilities in the system. Eventually, valve 20 stops oscillating and attains the neutral position (not shown in FIG. 4 ). Period T 2 is twice period T 1 and period T 3 is three times period T 1 , etc. The first three troughs of the curve in FIG. 4 b are lower than the maximum grabbing distance dotted line with the 4 th trough being above the maximum grabbing distance. The maximum grabbing distance is the maximum distance away from the fully closed position that armature 30 may be and still allow valve closing electromagnet 32 to attract armature 30 . If armature 30 is farther away from the fully closed position than the maximum grabbing distance, valve closing electromagnet 32 cannot attract armature 30 , that is, at the peak current of the driving system (not shown). For the example shown in FIG. 4 b , after de-energizing valve closing electromagnet 32 , armature 30 may be allowed to oscillate three periods and still allow valve closing electromagnet 32 to catch armature 30 at around the end of period T 3 . If valve closing electromagnet 32 were not caught before valve 20 begins the fourth oscillation, valve 20 would not come to a position where valve closing electromagnet 32 could exert enough attractive force to catch valve 20 . The discrete times at which the valve can be grabbed are designated with an X on the abscissa of FIG. 4 b.
Referring now to FIG. 5 a , piston position as a function of crank angle degree is shown. FIG. 5 b shows piston speed as a result of the change in piston position. As the piston travels from top dead center (TDC) to bottom dead center (BDC) accomplished during the 0–180 crank degrees of crank rotation, the piston speed is a 0 speed at 0 degrees, at a maximum at approximately 90 crank degrees, and returns to 0 speed at about 180 degrees. Peak piston speed occurs during the middle of the intake stroke. Because flow through the valve is influenced by the vacuum generated in the combustion chamber which is induced by the piston movement, peak flow through the valve is related to the maximum piston speed.
In both FIGS. 5 a and 5 b , purely sinusoidal piston movement and speed are shown. The actual piston move and piston movement deviate slightly from a sinusoid, actual movement being a function of crank throw and stroke length. FIGS. 5 a and 5 b are approximations to true piston movement.
It is well known to those skilled in the art, that combustion stability is poor at low torque engine conditions, partially due to low turbulence levels in the combustion chamber. Turbulence is enhanced when the speed of gases flowing through the intake valve is increased. By timing the opening of intake valve 20 such that piston 14 is near its maximum speed increases the flow velocity through intake valve 20 . With a direct fuel injected engine, such as shown in FIG. 1 , fuel air mixing is enhanced when fuel injection occurs concurrent with maximum flow through intake valve 20 . Intake flow blows by the injector shearing the fuel jet and causing the air to entrain fuel droplets.
Referring to FIG. 6 , a method by which the present invention can be used to advantage is illustrated with a flow chart. The algorithm starts in block 80 . Control passes to block 82 in which it is determined if piston speed is in an appropriate range, meaning whether the piston is moving sufficiently fast to cause a high intake flow when intake valve is opened. If not, wait until a positive result in block 82 , from which control passes to block 84 . The valve closing magnet is de-energized allowing intake valve 20 to open. Control passes to block 86 in which it is determined whether the flow of gases through intake valve 20 is appropriate for beginning fuel injection. If a negative result in block 86 , wait until a positive result, from which control passes to block 88 . In block 88 the fuel injector is actuated. Control then passes to block 90 in which it is determined whether intake valve 20 is in an appropriate range to catch intake valve 20 . If so, control passes to block 92 in which the valve closing electromagnet is actuated to close intake valve 20 .
In an alternative embodiment, decision blocks 82 , 86 , and 90 of FIG. 6 are supplanted by a model of valve dynamics, flow through the intake valve, piston speed, etc. That is, a model is used to determine at what crank angle the piston speed is appropriate, based on current operating conditions, to send out a signal to de-energize the valve closing electromagnet, and similarly for blocks 86 and 90 . In an alternative embodiment, lookup tables are used in place of a model of the system to determine when to perform the de-energization, fuel injection, and energization. The lookup table is a function of one or more of engine speed, manifold vacuum pressure, and desired torque.
Another factor in determining the time at which the intake valve is caused to open is the amount of air desired in the cylinder. There are situations in which the intake valve is opened earlier or later than the exact optimal time for inducing intake turbulence so that the appropriate amount of air is inducted into the cylinder; the desire amount of air is determined so as to supply the desired amount of engine torque.
In one embodiment, it is desirable to open the intake valve more than once during the intake stroke. Some air is inducted during the first opening and when the intake valve is closed, further downward motion of the piston causes a vacuum to develop in the cylinder. When the intake valve is opened a second time, the pressure difference across the valve induces a greater degree of turbulence than if the valve were left open. Because of the rush of air that is induced when the valve is opened, mixing is enhanced.
In yet another embodiment, fuel is injected between the first opening and the second opening. If the rush of air is too forceful, the injected fuel may be pushed against cylinder walls. Thus, by injecting the fuel in between the two intake periods, the fuel is injected into highly turbulent air, but not pushed against the wall.
While several modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize alternative designs and embodiments for practicing the invention. The above-described embodiments are intended to be illustrative of the invention, which may be modified within the scope of the following claims.
|
A system and method are disclosed for operating an internal combustion engine in which the intake valves are electromechanical valves and the engine has direct fuel injection. By opening the intake valves during the intake stroke when the piston is moving at its maximum speed, the turbulence through the intake valve is enhanced, thereby increasing combustion speed, and hence combustion stability at low torque, low speed operating conditions. Furthermore, if the fuel injection interval occurs when flow of gases through the intake is highest, air-fuel mixing is improved.
| 8
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of provisional applications Serial No. 60/169,855, filed Dec. 9, 1999; Serial No. 60/170,380, filed Dec. 13, 1999; Serial No. 60/178,010, filed Jan. 24, 2000; and Serial No. 60/178,042, filed Jan. 24, 2000, now abandoned.
TECHNICAL FIELD
This invention relates to structured packing for an exchange column, and, particularly, for a mass transfer column such as a cryogenic rectification column.
BACKGROUND OF THE INVENTION
Various types of exchange columns have been known in which a gas and a liquid come into contact with one another, generally in countercurrent flow. It is common to use packing elements formed of corrugated sheets or plates which contact one another and are disposed in parallel to the column axis to encourage contact between the liquid and gas. In such cases, the folds or corrugations of the plates are disposed at an angle to the column axis. Additionally, improvements have been made to structured packing to decrease the gas flow resistance in the lower region of a structured packing section, thus increasing the packing capacity. More specifically, the pressure drop associated with the gas or vapor entry into the structured packing section is made to be less than the pressure drop which would be experienced if the configuration of the structured packing in the lower region had the same configuration as in the upper portion of the structured packing section. Such improvements are described in U.S. Pat. No. 5,632,934. This patent contemplates a bulk region and a base region. The patent discloses the base region having various configurations to reduce the pressure drop therein.
A packing structure is needed which has further increased performance characteristics.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a packing section whose geometry can be varied in a base region, a top region, or both, to accomplish various performance requirements of a column.
A further object of the present invention is to provide a packing section wherein surface texturing is selectively used throughout the packing section to provide the desired performance of the column.
Accordingly, the present invention provides for a packing section, including a plurality of vertically oriented, diagonally-cross-corrugated packing sheets defining a section height. The section height has a base region, a bulk region, and a top region. The base region has a first particular geometry different from the geometry of the bulk region. The top region has a second particular geometry different from the geometry of the bulk region, and different from the first geometry of the base region.
The invention further includes a packing section having a plurality of vertically oriented, diagonally cross-corrugated packing sheets defining a section height. The section includes a base region, a bulk region, and a top region. The bulk region includes surface texturing. Further, at least a portion of at least one of the base region and the top region does not have surface texturing.
The invention further provides for a packing section having a plurality of vertically oriented, diagonally cross-corrugated packing sheets defining a section height. The section has a base region, a bulk region, and a top region. The bulk region includes generally horizontal fluting. Further, at least a portion of at least one of the base region and the top region includes generally vertical fluting.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, 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.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which form apart of this specification, and are to be read in conjunction therewith, and in which like reference numerals are used to indicate like parts in the various views:
FIG. 1 is a top perspective view of various packing sections disposed one on top of one another as if positioned in a column;
FIG. 2 a is a top plan view of a single packing section;
FIG. 2 b is a top plan view of a cross section through a column showing various packing bricks making up a packing section layer;
FIG. 3 is a top perspective view of a packing section;
FIG. 4 is a top perspective view of two structured packing sheets embodying a first embodiment of the present invention;
FIG. 5 is a view similar to FIG. 4, but showing a second embodiment of the present invention;
FIG. 6 is a top perspective view of a single packing sheet showing a third embodiment of the present invention;
FIG. 7 is a front elevational view of a single packing sheet showing a fourth embodiment of the present invention;
FIG. 8 is a front elevational view of a single packing sheet showing a fifth embodiment of the present invention;
FIG. 9 is a front elevational view of a single packing sheet showing a sixth embodiment of the present invention;
FIG. 10 is a top perspective view of a single packing sheet showing a seventh embodiment of the present invention;
FIG. 11 is a front elevational view of a single packing sheet showing an eighth embodiment of the present invention;
FIG. 12 is a front elevational view of a single packing sheet showing a ninth embodiment of the present invention;
FIG. 13 is a front elevational view of a single packing sheet showing a tenth embodiment of the present invention; and
FIG. 14 is a front elevational view of a single packing sheet showing an eleventh embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to an improvement of U.S. Pat. No. 5,632,934, the disclosure of which is incorporated herein by reference. More specifically, U.S. Pat. No. 5,632,934 is directed to varying the configuration in the base region of a packing section, and discloses various different configurations in the base region to decrease the gas pressure drop in the base region. For instance, the patent discloses reducing gas resistance in the base region by having: (1) staggered sheets in the base region, (2) flat portions in the base region, (3) reduced cross section corrugations in the base regions, (4) steeper corrugations in the base region, (5) orifices in the base region, (6) sawtooth configurations in the base region, and (7) louvers in the base region. The present invention improves the performance of this known packing, as will be more fully described below.
With reference to FIG. 1, structured packing includes vertically oriented sheets with corrugations at an angle to the vertical axis of a column. Sheets, are arranged such that the corrugation direction of adjacent sheets is reversed to one another. The packing is installed in the column as layers or sections “S”. Adjacent sections S are rotated around a vertical axis to enhance mixing, as is shown in FIG. 1 .
In smaller columns, each layer may be comprised of a single section or brick of packing formed by affixing individual sheets together, as is shown in FIG. 2 a. In larger columns, each packing section S may be made from several bricks “B” that fit together to fill a cross section of the containing vessel, as is shown in FIG. 2 b. The complete packing column comprises multiple sections S of packing, the number of sections S being set by the height of packing required to perform the separation.
With reference to FIG. 3, one packing section S is shown. Packing section S has a height “H”, a top region “T”, a bulk region “U” and a base region “L”. Typically, the height of the base region L and the height of top region T each would be about 5% to 10% of the section height H, but, depending upon a number of considerations and particular performance characteristics of the column, could each be smaller or each be as large as one-third of the section height H. Region L and region T need not be the same height, and could significantly vary depending upon the desired performance characteristics of the column.
It has been found preferable to have the height of region L and region T be dependent upon the specific surface area of the packing. More specifically, the specific surface area of a packing is a function of the crimp size of the sheets. The smaller the crimp size, generally the larger the specific surface area. Specific surface area is usually defined as the surface area of the sheets in a packing section (in m 2 ) divided by the volume of the packing section (in m 3 ). It has been found that the larger the specific surface area for a given section height H, the smaller the height of regions L and T need to be. Table 1 below demonstrates this correlation for a section height H about 8 in. to 11 in.
TABLE 1
Specific Surface
Height of Region T
Height of Region L
Area (m 2 /m 3 )
(in.)
(in.)
750-1200
(m 2 /m 3 )
1/4 in.-3/4 in.
1/4 in.-3/4 in.
350-750
(m 2 /m 3 )
1/2 in.-1 in.
1/2 in.-1 in
100-350
(m 2 /m 3 )
3/4 in.-2 in.
3/4 in.-2 in.
With reference to FIG. 4, one embodiment of the present invention is shown. In this embodiment, two adjacent packing sheets 20 are shown. The bulk region U of the sheets 20 have angled corrugations, and adjacent sheets 20 extend in different directions. Top region T of each sheet 20 includes generally vertical corrugations 22 . More specifically, these corrugations can be of the same height and cross section as the corrugations found in bulk region U; however, they are angled more vertically than the corrugations in bulk region U. The steeper corrugations 22 are shown in FIG. 4 as being vertical; however, they need not necessarily be vertical. They may have, instead, a closer to vertical angle than the corrugations found in bulk region U. Further, the transition from the corrugations in bulk region U to vertical corrugations 22 is shown as abrupt. A gradual transition is also contemplated. With still further reference to FIG. 4, sheets 20 are shown as having flat sections 24 in base region L. More specifically, there are generally no corrugations at all in base region L. The present invention of having different geometries in top region T and base region L allows further increased performance of a packing section. More specifically, the steeper corrugations in top region T allow easier transitioning of vapor into the above packing element, while flat section 24 in base region L helps decrease vapor pressure drop in base region L and in the transition region.
A further embodiment is shown in FIG. 5, wherein sheets 20 have the same vertical corrugations 22 in top region T; but, however, have reduced cross section corrugations 26 in base region L. More specifically, corrugations 26 are smaller in height than the corrugations found in bulk region U. Again, this difference in geometry recognizes the needs of the different regions of the packing section to accomplish transition and pressure reduction.
Although the above two embodiments are disclosed, as is apparent, it may be desirable to have other different geometries in the top region T and the lower region L. Such geometries can be as those disclosed in U.S. Pat. No. 5,632,934.
It is known to utilize surface texturing on packing sheets 20 . The term “surface texturing”, as used herein, is to be understood as denoting any roughening, slitting, stamping and/or impressing of the sheet surface. Examples of surface texturing include, but are not limited to, grooving (“fluting”), impression of a pattern, for example, a herringbone or waffle pattern, or small deformed slits. An example of “fluting” can be found in U.S. Pat. No. 4,296,050, the disclosure of which is incorporated herein by reference. This patent discloses fine fluting in the form of grooves. The fine fluting results in spreading of liquid over the sheet surfaces as a result of capillary action.
With reference to FIG. 6, a further embodiment of the present invention is shown. More specifically, in this embodiment, a base region L of a sheet 20 is shown, wherein the base region L does not have the surface texturing shown in the bulk region U and the top region T. The embodiment shown in FIG. 6 discloses the surface texturing in region U and region T as the fine fluting of a packing sheet. The fine fluting extends generally horizontally and results in the spreading of liquid across the face of the sheet. Although the “surface texturing” shown is fine fluting, any other surface texturing could also be used. In the base region L, there may not be a need to have the liquid move across the packing, but instead to have the liquid move quickly off the packing sheet to the packing section below. Therefore, the absence of any surface texturing in base region L can accomplish this. Additionally, top region T can also be void of surface texturing to accomplish the desired performance characteristics of the column. Therefore, a sheet is contemplated where both top region T and base region L, or only base region L or only top region T is devoid of surface texturing.
With reference to FIG. 7, a further embodiment of the present invention is shown. More specifically, a sheet 20 is shown having a bulk region U with fine flutings extending generally horizontal to the axis of vertical corrugations 22 . However, top region T and base region L do not have any surface texturing.
With reference to FIG. 8, a further embodiment is shown which is similar to FIG. 7; however, top region T, while having vertical corrugations 22, does not have fine fluting. However, base region L does have fine fluting in addition to vertical corrugations 22 .
FIG. 9 is a further variation of FIGS. 7 and 8, wherein top region T has fine fluting and vertical corrugations 22 while bottom region L does not have fine fluting, but does have vertical corrugations 22 .
As discussed above, fine fluting has been shown extending generally horizontal to the axis of the column. As is apparent, any other surface texturing could be used.
It has been found that it may be desirable to enhance the removal of liquid from a section or a sheet to have generally vertical fine fluting in at least a portion of base region L or top region T. With reference to FIG. 10, a sheet 20 is shown, wherein there are generally horizontal fine flutings in the bulk region U and top region T; however, there is vertical fine fluting in base region L. As is apparent, there could be other variations wherein the generally vertical fine fluting is utilized in both top region T and bottom region L, or just in the top region T and not in the base region L.
With reference to FIG. 11, a still further embodiment is shown wherein top region T and base region L of a sheet 20 each have vertical corrugations 22 . Additionally, each of top region T and base region L have generally vertical fine fluting, as opposed to the generally horizontal fine fluting found in base region U.
With reference to FIG. 12, another embodiment is shown wherein a sheet 20 includes top region T and base region L with vertical corrugations 22 . Additionally, top region T has generally vertical fine fluting, bulk region U has generally horizontal fine fluting, and base region L has no fine fluting at all.
A still further embodiment is shown in FIG. 13, again wherein both top region T and base region L have vertical corrugations 22 but wherein top region T has no fine fluting, bulk region U has generally horizontal fine fluting, and bottom region L has generally vertical fine fluting.
Although the vertical fluting in the drawings are shown as vertical, any fluting that extends at a steeper angle than the generally horizontal fluting could be used to possibly enhance the performance characteristics of the column. Additionally, the generally horizontal fine fluting in bulk region U could be any other suitable surface texturing.
As is apparent, various surface texturing combinations can be utilized in top region T and bottom region L, with the different geometries disclosed in U.S. Pat. No. 5,632,934. For instance, any of the generally horizontal fine fluting and vertical fluting combinations disclosed above could be utilized in conjunction with the flat sheet 24 geometries, or reduced corrugation height geometry 26 discussed above.
Further, with respect to all the above embodiments, in addition to surface texturing, a sheet 20 could have a plurality of discrete apertures disposed throughout. Such apertures could be as disclosed in U.S. Pat. No. 4,296,050. If such apertures are disposed in a sheet 20 , it may be desirable to have top region T or bottom region L, or both, be devoid of such apertures in addition to being devoid of surface texturing.
The present invention may be used in any distillation, absorption, or stripping process, which may employ structured packing. Examples, but not limitations of the structured packing include, oil fractionations, hydrocarbon separations, alcohol distillations, and cryogenic rectification such as cryogenic air separation systems.
From the foregoing, it will be seen that this invention is one well-adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
For example, as shown in FIG. 14, sheet 20 is shown as having a bulk region U with fine fluting extending generally horizontal to the axis of the column. Bulk region U also has apertures 28 disposed throughout. Top region T and bottom region L each have vertical corrugations 22 . However, top region T and base region L do not have any surface texturing, nor do they have any apertures 28 . Thus, the surfaces of top region T and base region L are smooth.
|
A packing section includes a plurality of vertically oriented, diagonally cross-corrugated packing sheets defining a section height. The section height has a base region, a bulk region, and a top region. The base region has a first particular geometry different from the geometry of the bulk region. The top region has a second particular geometry different from the geometry of the bulk region, and different from the first particular geometry of the base region.
| 8
|
BACKGROUND
[0001] Single nucleotide polymorphisms (SNPs), a set of single nucleotide variants at genomic loci, are distributed throughout a genome. A single nucleotide polymorphism can be “allelic.” That is, due to the existence of the polymorphism, some members of a species may have the unmutated sequence (i.e. the wild-type allele) whereas other members may have a mutated sequence (i.e. the mutant allele). In animals, a polymorphism may cause genetic recessive disorders. These disorder include bovine leukocyte adhesion deficiency, citrullinemia, maple syrup urine disease, deficiency of uridine monophosphate synthase, a-mannosidosis, and generalized glycogenosis. In humans, an example of genetic recessive disorders is cystic fibrosis, which affects about {fraction (1/2000)} individuals of the entire Caucasian population. In microbial pathogens, such as bacteria and viruses, single nucleotide polymorphisms are associated with different pathological effects, and therefore have bearing on therapy of, and long-term prognosis for, patients infected with the pathogens. A method is in need for efficiently identifying and quantifying a SNP-containing nucleic acid.
SUMMARY
[0002] This invention relates novel primers, probes, and nucleic acids amplified from Hepatitis B virus (HBV) and their use in simultaneously genotyping and quantifying HBV.
[0003] In one aspect, the invention relates a method for simultaneously identifying a SNP in a target nucleic acid (e.g., as the entirety or part of a genome) from an HBV and quantifying the target nucleic acid. The identification and quantification are carried out simultaneously.
[0004] This method requires the use of a first probe (or sensor probe) and a second probe (or anchor probe). The first probe is identical or complementary to a first sequence of the target nucleic acid that covers a base corresponding to a SNP. The second probe is identical or complementary to a second sequence of the target nucleic acid that does not cover the base corresponding to the SNP. The first probe is covalently bounded to a first fluorophore, and the second probe is covalently bounded to a second fluorophore. One of the first and second fluorophores is a donor fluorophore, and the other is an acceptor fluorophore, so that, when the first probe and the second probe are hybridized to the target nucleic acid, the donor fluorophore and the acceptor fluorophore are in close proximity to allow fluorescence resonance energy transfer (FRET) between them.
[0005] The method includes amplifying, by a polymerase chain reaction (PCR) with a pair of primers, a target nucleic acid in a sample to form a double-stranded nucleic acid product containing the first sequence and the second sequence. The above-mentioned first and second probes are hybridized to the nucleic acid product during the annealing step of the PCR to form a first duplex and a second duplex, respectively. The two probes can be hybridized to the same strand of the nucleic acid product. They can also be hybridized to different strands of the nucleic acid product and allow the donor and acceptor fluorophores to be in close proximity. For example, the two probes can be hybridized to sequences at a fork or bubble formed by the two strands of the nucleic acid product.
[0006] The target nucleic acid in a sample is quantified by monitoring the fluorescent emission of the acceptor fluorophore on the first probe at the end of the annealing phase of each PCR cycle. It can be achieved by comparing the intensity of the fluorescent emission with a value predetermined from a solution containing a known concentration of the target nucleic acid. It can also be achieved by obtaining a cross point value (Cp value) of the PCR reaction and comparing the Cp value to another Cp value predetermined from a solution containing a known concentration of the target nucleic acid by the method described in, e.g., Mackay I. et al., Nucleic Acids Res. 30: 1292-1305, 2002.
[0007] After the PCR reaction, the temperature is raised to above the melting temperature of the duplex formed by the first probe and its complementary sequence. When this duplex is dissociated, the FRET between the donor and acceptor fluorophores is disrupted. Identification of a SNP in the target nucleic acid is achieved by monitoring fluorescent emission change of the acceptor fluorophore on the first probe upon irradiation of the donor fluorophore with an excitation light, the change being a function of the elevated temperature. For example, to identify a SNP, one can (1) generate a first derivative melting curve of the first duplex, which includes a fluorescently labeled probe, based on fluorescent emission change as a function of temperature; (2) determine a temperature value corresponding to a melting peak on the curve; and (3) compare the temperature value with the melting temperature of the duplex formed by the first probe and its complementary sequence. A SNP in the target nucleic acid is present when the temperature value is lower than the melting temperature and is absent when the temperature value is the same as the melting temperature.
[0008] In another aspect, the invention features a pair of primers for amplifying a target nucleic acid of HBV, such as forward primer TACTGCGG (SEQ ID NO: 13) and reverse primer GGTGAAGCGA (SEQ ID NO: 14); forward primer CGTGGAACC (SEQ ID NO: 17) and reverse primer GGTGAAGCGA (SEQ ID NO: 14); or forward primer CTCAGGCCA (SEQ ID NO: 20) and reverse primer AACGCCGCAGACACATCCA (SEQ ID NO: 6). Each primer is 8-50 nucleotides (e.g., 15-40 or 18-30 nucleotides) in length. More examples of such a pair of primers include forward primer CCGATCCATACTGCGGAAC (SEQ ID NO: 9) and reverse primer GCAGAGGTGAAGCGAAGTGCA (SEQ ID NO: 10); forward primer GCATGCGTGGAACCTTTGTG (SEQ ID NO: 1) and reverse primer CAGAGGTGAAGCGAAGTGC (SEQ ID NO: 2); and forward primer TCATCCTCAGGCCATGCA (SEQ ID NO: 5) and reverse primer AACGCCGCAGACACATCCA (SEQ ID NO: 6).
[0009] In still another aspect, the invention features a pair of probes used together for identifying a SNP in a target nucleic acid of HBV and quantifying the target nucleic acid, such as a first probe TTGTCTACG (SEQ ID NO: 18) and a second probe CGCTGAATC (SEQ ID NO: 19); sensor probe TACGCGGACTC (SEQ ID NO: 15) and anchor probe GCCTTCTCATC (SEQ ID NO: 16); or sensor probe ACACGGGTGTTTCC (SEQ ID NO: 21) and anchor probe ATTGAGAGAA (SEQ ID NO: 22). Each probe is 9-50 nucleotides in length, e.g., 15-40 or 18-30 nucleotides in length. More examples of such a pair of probes include sensor probe ACGTCCTTTGTCTACGTCCCG (SEQ ID NO: 3) and anchor probe CGGCGCTGAATCCCGCGGAC (SEQ ID NO: 4); sensor probe TCTTTACGCGGACTCCCC (SEQ ID NO: 1) and anchor probe TCTGTGCCTTCTCATCTGCCGGACC (SEQ ID NO: 12); and sensor probe AAGACACACGGGTGTTTCCCC (SEQ ID NO: 7) and anchor probe GAAAATTGAGAGAAGTCCACCACGAGTCTA (SEQ ID NO: 8).
[0010] In yet another aspect, the invention features a nucleic acid that is obtained from amplification of a HBV nucleic acid template. This nucleic acid contains the sequence of SEQ ID NO: 15, 18, or 21, or its complementary sequence. The nucleic acid is 100-1,000 (e.g., 200-700 or 300-500) nucleotides in length. This nucleic acid can be hybridized with the above-mentioned probes and primers for identifying and quantifying a SNP-containing target nucleic acid of HBV.
[0011] In a further aspect, the invention features a kit for simultaneously identifying a single nucleotide polymorphism in a target nucleic acid of HBV and quantifying the target nucleic acid. The kit contains 1, 2, or 3 pairs of the primes and/or probes described above.
[0012] The details of one or more embodiments of the invention are set forth in the accompanying description below. Other advantages, features, and objects of the invention will be apparent from the detailed description and the claims.
DETAILED DESCRIPTION
[0013] The present invention relates to a method for simultaneously genotyping and quantifying Hepatitis B Virus. This method requires the use of a first probe and a second probe. The first probe can be designed based on a known SNP in a target nucleic acid, and also based on its properties, e.g., GC-content, annealing temperature, or internal pairing, which can be determined using software programs. For identifying a SNP in nucleic acids from different members of a species, the first probe should be identical or complementary to a sequence containing a SNP that can be used to distinguish between at least two different genotypes of the species. Such a sequence can be determined based on standard sequence alignment of the DNA from different members of the species in a manner similar to that described below in the “Design of probes and primers” section. The DNA sequences of different members can be obtained from any suitable databases, e.g., www.ncbi.nlm.nih.gov/PMGifs/Genomes.
[0014] The first probe can hybridize to one SNP allele, e.g., a wild-type allele, to form a duplex with no mismatched base, and to another SNP allele, e.g., a mutant allele, to form another duplex with mismatched bases at the SNP site(s). Due to the mismatches, the melting temperature (Tm) of the latter duplex is lower that that of the former. The first probe can be optimized on a gene-by-gene basis to discriminate between a wild-type allele and a mutant allele. One can confirm empirically the ability of the first probe to hybridize to a mutant allele or a wild-type allele to form duplexes. One can also confirm the difference between the melting temperatures of the two duplexes are sufficiently great (e.g., 2° C.) so that the difference can be detected.
[0015] SNP-containing sequences in HBV include TACGCGG A CTC (SEQ ID NO: 15), TTGT C TACG (SEQ ID NO: 18) and AC A C G GGTG T T T CC (SEQ ID NO: 21). (The bases corresponding to SNPs are bold and underlined). These SNPs can be used to distinguish HBV genotypes A to G. See Tables 1 and 2, and the “Simultaneous quantification and identification of HBV” section below.
[0016] The SNP-containing sequences are preferably flanked by sequences that are conserved among different genotypes of a species. As described below, the conserved flanking sequences are important for designing a second probe and PCR primer pairs.
[0017] The second probe is designed based on two principles. First, it contains no SNP and is identical or complementary to a sequence conserved among different genotypes of a species. Second, the conserved sequence should be adjacent to the above-described SNP-containing sequence. This is to ensure that, after the first and the second probes hybridize to a target nucleic acid, the two probes are in close proximity, e.g., 1-3 bases apart.
[0018] Each of the first and second probes is labeled with a fluorophore that can be detected, directly or indirectly, by techniques well known in the art. One of the fluorophore is an acceptor fluorophore, and the other is a donor fluorophore. The emission spectrum of the donor fluorophore overlaps the excitation spectrum of the acceptor fluorophore. The donor and acceptor fluorophores are so located that, upon hybridization of the probes to a target nucleic acid, they are within a short distance of each other to allow FRET to takes place between them. The emission of the acceptor can be detected and/or quantified by techniques well known in the art. Any pair of fluorophores that having overlapped emission and excitation spectra can be labeled to the two probes. LightCycler-Red 640 is an example of an acceptor fluorophore, and fluorescein is an example of a donor fluorophore.
[0019] To simultaneously quantify and identify a target nucleic acid, the above-described probes are mixed with the target nucleic acid and subjected to a Real-time PCR reaction. A pair of primers used for the PCR can be designed based on principles known in the art. In particular, the primers should be identical or complementary to sequences that flank a SNP and are conserved among different genotypes of a species. The pair of primers can be used to amplify a target nucleic acid contained a SNP. The nucleic acid can be obtained from any suitable source, e.g., a tissue homogenate, blood samples and can be DNA or RNA (in the case of RNA, reverse transcription is required before PCR amplification). PCR amplification can be carried out following standard procedures. See, e.g., Innis et al. (1990) PCR Protocols: A Guide to Methods and Applications Academic Press, Harcourt Brace Javanovich, New York. In one example, Real-time PCR amplification was carried out using a commercially available Real-PCR system (e.g., LightCycler marketed by Roche Molecular Diagnostic.).
[0020] The 3 steps of PCR amplification denaturing, annealing and elongating, can be repeated as many times as needed to produce the desired quantity of an amplification product corresponding to the target nucleic acid. The required cycling number depends on, among others, the nature of the sample. If the sample is a complex mixture of nucleic acids, more cycling steps will be required to amplify the target sequence sufficient for detection. Generally, the cycling steps are repeated at least about 20 times, but may be repeated as many as 40, 50, 60, or even 100 times. The PCR product can anneal with the above-described probes and is used to identify and quantify the target nucleic acid.
[0021] To quantify a target nucleic acid, fluorescence emitted from the acceptor fluorophore is monitored at the end of the annealing phase of each PCR cycle upon irradiation of the donor fluorophore. The intensity of the fluorescence emission is a function of the amount of the amplified nuclei acid product, which, in turn, is a function of the original concentration of the target nucleic acid and PCR cycle numbers. When enough cycles are carried out, the rates for the accumulation of the amplified nuclei acid product and for the change in the fluorescence emission enter a log-linear phase. The PCR cycle number corresponding to the entry point (the cross point value, or Cp value) can be determined by plotting the fluorescence emission intensity against the PCR cycling number. The Cp value thus obtained is then compared to a predetermined Cp value that corresponds to a known original concentration of a standard nucleic acid. A series of such predetermined Cp values can be obtained in the manner described below in the “Quantification of HBV” section. Accordingly, one can derive the corresponding original concentration of the target nucleic acid by comparing a given Cp value to a series of predetermined Cp values.
[0022] Alternatively, one can simply compare the emission intensity with a predetermined emission intensity value to quantify a target nucleic acid. The predetermined emission intensity value is acquired in the same manner except that the original concentration of nucleic acid is known.
[0023] To identify a target nucleic acid, its amplicon is subjected to a melting curve analysis at the end of the PCR amplification. The reaction is heated slowly, e.g., at a transition rate of 0.5° C./sec, to a temperature higher than the Tm of the first probe. Meanwhile, fluorescence emitted from the acceptor fluorophore is monitored upon irradiation of the donor fluorophore. The intensities (F) are plotted against temperature (T) to generate a melting curve. Then, a first derivative of the melting curve (i.e., a first derivative melting curve) is generated by plotting the negative derivative of F with respect to temperature (−dF/dT) against T to located a melting peak(s). The temperature value corresponding to the melting peak is then compared with the melting temperature of the first probe. In a preferred embodiment, the melting curve analysis is performed using LightCycler analysis software 3.5 (Roche Diagnostics Applied Science, Mannheim Germany). A SNP in the target nucleic acid is present when the temperature value is lower than the melting temperature and is absent when the temperature value is the same as the melting temperature. Unexpectedly, the method described herein is very efficient as it simultaneously quantifies and identifies a SNP-containing nucleic acid.
[0024] The specific examples below are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. Without further elaboration, it is believed that one skilled in the art can, based on the description herein, utilize the present invention to its fullest extent. All publications cited herein are hereby incorporated by reference in their entirety.
[0025] Design of Probes and Primers
[0026] 216 full-length HBV DNA sequences were obtained from the database at www.ncbi.nlm.nih.gov/PMGifs/Genomes/viruses.html. Among them, 175 sequences were identified as belonging to genotypes A to G, by a phylogenic analysis using the CLUSTRLW Multiple Sequence Alignment, DRAWTREE, and DRAWGRAM programs provided by Biology WorkBench (workbench.sdsc.edu/).
[0027] Among the 175 sequences, 47 were genotype B, and 49 were genotype C. The sequences of the two genotypes were aligned and compared to identify regions that contain SNPs and are flanked by sequences conserved between the two genotypes by the CLUSTRLW Multiple Sequence Alignment program. Three regions were identified, and three sets of primer pairs and probe pairs were designed based on the sequences of the regions according to principles suggested by TIB MOLBIOL (Gerlin, Germany). The primer pairs can be used, via PCR, to prepare amplicons from respective target nucleic acids. The genomic locations of the amplicons, primer pairs, and probe pairs are summarized in Table 1.
TABLE 1 Amplicons, primer pairs, and probe pairs for identifying and quantifying SNPs in HBV. SEQ Product Tm (Melting ID Position Size Temperature) Amplicon NO. Sequences (5′-3′) (nt) (bp) (° C.) Set 1 Forward primer 1 5′-GCATGCGTGGAACCTTTGTG-3′ 1232-1251 368 Genotype B 57.7 Reverse primer 2 5′-CAGAGGTGAAGCGAAGTGC-3′ 1599-1581 Genotype C 66.3 Anchor probe 4 FLU-5′-CGGCGCTGAATCCCGCGGAC-3′-P 1436-1455 ΔTm = 8.6 Sensor probe 3 5′-ACGTCCTTTGT C TACGTCCCG-LC-Red 640-3′ 1414-1434 ±30% ΔTm = ±2.5 SNP site C/T, nt 1425 Set 2 Forward primer 9 5′-CCGATCCATACTGCGGAAC-3′ 1261-1279 340 Genotype B 60.9 Reverse primer 10 5′-GCAGAGGTGAAGCGAAGTGCA-3′ 1600-1580 Genotype C 54.8 Anchor probe 12 FLU-5′-TCTGTGCCTTCTCATCTGCCGGACC-3′-P 1552-1576 ΔTm = 6.1 Sensor probe 11 5′-TCTTTACGCGG A CTCCCC-LC-Red 640-3′ 1533-1550 ±30% ΔTm = ±1.8 SNP site A/T, nt 1544 Set 3 Forward primer 5 5′-TCATCCTCAGGCCATGCA-3′ 3192-3209 416 Genotype B 64.3 Reverse primer 6 5′-AACGCCGCAGACACATCCA-3′ 392-374 Genotype C 46.8 Anchor probe 8 FLU-5′-GAAAATTGAGAGAAGTCCACCACGAGTCTA-3′-P 278-249 ΔTm = 16.3 Sensor probe 7 5′-AAGACAC A C G GGTG T T T CCCC-LC-Red 640-3′ 301-281 ±30% ΔTm = ±4.9 SNP sites A/G, nt 285; A/G, nt 287; G/A, nt 292; T/C, nt 294
[0028] Amplicon 1 contains 1 SNP at nt 1425 with a C/T polymorphism. Amplicon 2 contains 1 SNP at nt 1544 with an A/T polymorphism. These two SNPs are located in the HBx gene. Amplicon 3 contains 4 SNPs at HBV nt 285 (A/G polymorphism), nt 287 (G/A polymorphism), nt 292 (G/A polymorphism), and nt 294 (T/C polymorphism). These 4 SNPs are located in the HBs gene.
[0029] The primers and probes were synthesized by TIB MOLBIOL. The second (or anchor) probes were labeled with fluorescein at the 3′ end; and first (or sensor) probes covering the SNPs were labeled with a LC-Red 640 dye at the 5′ end. The 3′ ends of the sensor probes were also phosphorylated.
[0030] To confirm the presence of the SNPs in the amplicons, serum samples were collected from 40 hepatitis B patients, and DNA prepared in the same manner as described below in the “HBV DNA preparation” section. After amplifying with conventional PCR reactions, all of the resultant amplicons were sequenced using ABI PRISM Big-dye kits and analyzed via an ABI 3100 Genetics Analyzer (Applied Biosystems, Foster City, Calif.). Amplicons from 20 samples were identified to contain SNPs characteristic of genotype C HBV, and amplicons from the other 20 samples contained SNPs characteristic of genotype B.
[0031] HBV DNA Preparation
[0032] Serum samples were collected from 114 chronic hepatitis B Han Chinese patients. All of the patients had been followed by the outpatient clinics at National Taiwan University Hospital. To confirm the HBV infection, the samples were tested for the presence of HBsAg, anti-HBs, anti-HBc Igs, HBeAg, and anti-HBeAg using commercially available kits (Ausab, Ausria II, Murex HBeAg/anti-HBe, Abbott Laboratories, North Chicago, Ill.). The serum HBV DNAs were also analyzed by the branched chain DNA method (QUANTIPLEX tm HBV DNA Assay, Chiron Corporation, Emeryville, Calif.) according to the manufacturer's direction. All of above procedures conformed to the ethical guidelines of the 1975 Declaration of Helsinki.
[0033] HBV genomic DNA was then prepared from the samples described above using a High Pure Viral Nucleic Acid Kit (Roche Diagnostics Applied Science, Mannheim Germany). Briefly, 200 μL aliquot of serum sample from each patient was incubated with 200 μL of a binding buffer (containing 6M guanidine-HCl, 10 mM urea, 10 mM Tris-HCl, 20% Triton X-100 (vol/vol), 200 μg of poly (A), and 0.8 mg of proteinase K) at 72° C. for 10 min. The sample was then mixed with 100 μL of isopropanol, and loaded onto glass fibers pre-packed in a High Pure filter tube. After washing twice with an Inhibitor Removal Buffer (containing 100% ethanol, 20 mmol/L NaCl, and 2 mmol/L Tris-HCl), viral nucleic acid was recovered by eluting with 100 μL of H 2 O.
[0034] HBV DNA thus prepared was genotyped by traditional methods including PCR-RFLP, PCR with type-specific primers, and/or direct sequencing. 60 of the patient were identified to have genotype B HBV, and 46 of them were identified to have genotype C HBV. The HBVs from the other 8 patients could not be genotyped by these conventional methods.
[0035] Quantification of HBV
[0036] To quantify HBV, a copy-number standard curve was generated using plasmid pHBV 48. The plasmid was constructed by cloning a 1.5 mer of HBV (subtype adw1) genomic DNA fragment (nt 2851-3182/1-3182/1-1281) into the pGEM-3Z vector 8. The resultant plasmid was purified with a plasmid purification kit (QIAGEN GmbH, Hilden Germany), and quantified spectrophotometrically. The corresponding HBV titer (copy/mL) was then determined based on the mass per plasmid. The plasmid was serially diluted to obtain 10 samples with corresponding HBV titers ranging from 1×10 2 to 1×10 11 copy/mL. These 10 samples were used to generate the standard curve as described below.
[0037] 2 μL of each sample were, respectively, mixed with 0.5 μL of LightCycler FastStart DNA Master Hybridization Mixture (containing Taq DNA polymerase, PCR reaction buffer, 10 mM MgCl 2 , and dNTP mixture, Roche Diagnostics Applied Science, Mannheim Germany), 0.2 μL of 25 mM MgCl 2 , and the set 2 primers and probes described above in the “Design of probes and primers” section. The final volume was adjusted to 5 μl, so that the concentration for each primer was 5 μM, and that for each probe was 0.5 μM. The mixture was loaded into a capillary of a LightCycler, centrifuged, and placed in the LightCycler sample carousel (Roche Diagnostics Applied Science, Mannheim Germany).
[0038] A Real-time PCR reaction was performed as follows. An initial hot start to denature DNA was carried out at 95° C. for 10 minutes, which was followed by 55 cycles of denaturing at 95° C. for 5 seconds, annealing at 55° C. for 10 seconds, and extending at 72° C. for 20 seconds. The programmed temperature transition rate was 20° C./s for the denaturing/annealing transition and 5° C./s for the annealing/extension transition. Fluorescence emitted by LC-RED640 was monitored at the end of each annealing phase. Cp values of all samples were determined and plotted against the corresponding log concentrations of the samples to create a standard curve using the LightCycler software version 3.5. The standard curve exhibited a linear range from 10 2 to 10 11 copies/mL, indicating a detection limit of 10 2 copies/mL.
[0039] This standard curve was then tested for quantifying HBV DNA. Test samples included 15 samples (genotypes A˜F) from a HBV Genotype Panel (International Enzymes, Inc., Fallbrook, Calif.) and 4 samples from a QUANTIPLEX bDNA kit. All of the 19 test samples contained HBVs with known titers. Aliquots of these samples were subjected to the Real-time PCR, and Cp values determined in the same manner described above. The titers corresponding to the Cp values were obtained from the standard curve. For each sample, the quantification was performed 6 times (three duplications). The results indicated that the titers of all test samples were determined accurately.
[0040] The titers thus obtained via the above-mentioned method were compared with those obtained via 3 conventional methods, including NGI SuperQuant, Roche Amplicor, and Chiron Quantiplex bDNA assays. The 19 samples were quantified by the three conventional methods according to the manufacturers' manuals. Linear regression results indicated that the titers obtained via the above-mentioned method correlated significantly with those obtained via the 3 methods (gamma=0.9866, 0.9830, and 0.999, respectively). The within-run and between-run coefficients of variation were evaluated by Pearson correlation. The results (P<0.001) indicated a remarkable reproducibility of the method.
[0041] Identification of HBV
[0042] The above-described three sets of primer pairs and probes pairs were tested for differentiating between HBV genotypes B and C, which are endemically prevalent in Taiwan, China, and Japan.
[0043] 10 genotype B-containing samples and 10 genotype C-containing samples were selected from those described above. The samples were subjected to the Real-time PCR using set 2 primers and probes in the same manner described above in the “Quantification of HBV” section. After the PCR amplification, the reaction was held at 95° C. for 60 seconds, cooled to 45° C. with a transition rate of 0.5° C./s, held at 45° C. for 120 seconds, and heated to 80° C. at a transition rate of 0.5° C./s. Meanwhile, fluorescence 640 nm was monitored. After melting curves were generated for all samples, melting peaks were located by plotting the negative derivative of the fluorescence intensity with respect to temperature (−dF/dT) against temperature (T) using the LightCycler analysis software 3.5.
[0044] On the resultant plots, i.e., the first derivative melting curves, the melting peaks of all samples fell into two distinct clusters. The mean temperatures of the two clusters were characteristic of genotype B and C HBV (60.9° C. and 54.8° C., respectively). All of the 10 genotype B HBVs had Tms within the range 60.9±1.8° C. (i.e., ±30% of the ΔTm 6.1° C.), and all of the 10 genotype C HBVs had Tms within the range 54.8±1.8° C. Accordingly, 1.8° C. (or 30% of the ΔTm) was chosen as a cut-off value for differentiating between genotypes B and C. Similarly, the cut-off values (±2.5° C. and ±4.9° C.) using sets 1 and 3 amplicons and corresponding primers and probes were respectively determined. The means Tms and cut-off values were summarized in Table 1.
[0045] Then, the three sets of primer pairs and probe pairs were used to genotype all of the 60 genotype B and 46 genotype C HBVs described above in the “HBV DNA preparation” section. When using set 1 primer pairs and probe pairs, 103 of these 106 HBVs were genotyped correctly. Among the other three samples, one was not identified correctly, and two could not be identified unequivocally. When using sets 2 and 3 respectively, 1 and 2 HBVs could not be genotyped unequivocally. Nonetheless, after considering the results from any two of the three sets, all of the 106 HBVs were genotyped correctly.
[0046] As mentioned above in the “HBV DNA preparation” section, HBVs from the 8 patients could not be genotyped by conventional methods. These 8 HBVs were genotyped using the three sets of primer pairs and probe pairs. All of these HBVs were genotyped unequivocally. Direct sequencing further confirmed the genotyping results were correct. These results indicate that the genotyping method described herein is, unexpectedly, more accurate than the conventional HBV genotyping methods.
[0047] Simultaneous Quantification and Identification of HBV
[0048] HBVs in samples containing both genotypes B and C were genotyped and quantified simultaneously using the primer pairs and probe pairs and the method described above. Plasmids containing the genomes of genotypes B and C were obtained from National Taiwan University Hospital (Taipei, Taiwan). The genotypes B and C plasmids were mixed at ratios ranging from 10:1 to 1:10. The mixtures, with total titers of 10 7 plasmids/ml, were genotyped in the same manner described above the “Identification of HBV” section. The resultant first derivative melting curves showed melting peaks and Tms characteristic of genotypes B and C. Meanwhile, the Cp value of sample was found and the titer of plasmid in the sample determined in the same manner described above in the “Quantification of HBV” section. The results indicated that one can simultaneously genotype and quantify both a major and a minor HBV populations in a mixture. The detectable titer of the minor population can be as low as 10% of that of the major population. This one-tube method is unexpectedly efficient, accurate, and sensitive for simultaneously quantifying and identifying a SNP-containing nucleic acid.
[0049] Besides genotypes B and C, this method can also be used to identify other HBV genotypes. All of the 175 HBV DNA sequences mentioned above in the “Design of probes and primers” section were aligned in the same manner as that described in the same section. The primers and anchor probe were found conserved among the genotypes A-G. SNPs in corresponding amplicons were examined. The sequence variations and corresponding frequencies were summarized in Table 2.
TABLE 2 SNP sequence variations in HBV genotypes A˜G Sensor SNP Set1 Set2 Set3 Genotype (no.) C A A A G T A (17) T (16) / C (1) T (17) G (17) T (13) / G (3) /C (1) G (17) T (17) B (47) T (42) / C (5) A (46) / T (1) G (34) / A (12) /T (1) A (44) / C (3) G (47) T (45) / A (1) /G (1) C (49) C (37) / T (12) T (45) / A (2) G (46) / A (3) G (48) / A (1) A (47) / G (2) C (43) / A (5) /G (1) D (24) T (22) / C (2) A (22) / T (1) /G (1) G (24) A (24) G (24) T (24) E (2) C (2) T (2) G (2) G (2) G (2) T (2) F (28) T (25) / C (3) A (22) / T (2) /C (4) G (25) / T (3) C (22) / A (4) /G (2) G (27) / A (1) T (18) / G (10) G (8) T (8) T (8) G (8) G (8) G (8) T (8)
[0050] As shown in Table 2, most of the 7 genotypes (except genotypes B and D) had distinct SNP combinations in the three amplicons. HBVs, therefore, can be genotyped using the combination of the three sets primer pairs and probe pairs according to steps below:
[0051] (1) determining whether HBVs that are tested belong to genotypes A, C, E, and G (Group 1) or genotypes B, D, and F (Group 2) by using set 2 primers and probes;
[0052] (2) determining whether those of Group 1 belong to genotypes A and G or genotypes C and E by using set 1 primers and probes;
[0053] (3) differentiating between genotypes A and G, and between C and E by using set 3 primes and probes;
[0054] (4) determining whether those of Group 2 belong to genotype F or genotypes B and D by using set 3 primes and probes.
Other Embodiments
[0055] All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.
[0056] From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Thus, other embodiments are also within the scope of the following claims.
1
22
1
20
DNA
Artificial Sequence
primer
1
gcatgcgtgg aacctttgtg 20
2
19
DNA
Artificial Sequence
primer
2
cagaggtgaa gcgaagtgc 19
3
21
DNA
Artificial Sequence
Sensor probe
3
acgtcctttg tctacgtccc g 21
4
20
DNA
Artificial Sequence
Anchor probe
4
cggcgctgaa tcccgcggac 20
5
18
DNA
Artificial Sequence
primer
5
tcatcctcag gccatgca 18
6
19
DNA
Artificial Sequence
Primer
6
aacgccgcag acacatcca 19
7
21
DNA
Artificial Sequence
Sensor probe
7
aagacacacg ggtgtttccc c 21
8
30
DNA
Artificial Sequence
Anchor probe
8
gaaaattgag agaagtccac cacgagtcta 30
9
19
DNA
Artificial Sequence
Primer
9
ccgatccata ctgcggaac 19
10
21
DNA
Artificial Sequence
Primer
10
gcagaggtga agcgaagtgc a 21
11
18
DNA
Artificial Sequence
Sensor probe
11
tctttacgcg gactcccc 18
12
25
DNA
Artificial Sequence
Anchor probe
12
tctgtgcctt ctcatctgcc ggacc 25
13
8
DNA
Artificial Sequence
Primer
13
tactgcgg 8
14
10
DNA
Artificial Sequence
Primer
14
ggtgaagcga 10
15
11
DNA
Artificial Sequence
Sensor probe
15
tacgcggact c 11
16
11
DNA
Artificial Sequence
Anchor probe
16
gccttctcat c 11
17
9
DNA
Artificial Sequence
Primer
17
cgtggaacc 9
18
9
DNA
Artificial Sequence
Probe
18
ttgtctacg 9
19
9
DNA
Artificial Sequence
Probe
19
cgctgaatc 9
20
9
DNA
Artificial Sequence
Primer
20
ctcaggcca 9
21
14
DNA
Artificial Sequence
Sensor probe
21
acacgggtgt ttcc 14
22
10
DNA
Artificial Sequence
Anchor probe
22
attgagagaa 10
|
A method for simultaneously genotyping and quantifying Hepatitis B Virus. Also disclosed are (1) a pair of primers containing, respectively, the sequences of SEQ ID NOs: 13 and 14, SEQ ID NOs: 17 and 14, or SEQ ID NOs: 20 and 6, each primer being 8-50 nucleotides in length; (2) a pair of probes, containing, respectively, the sequences of SEQ ID NOs: 18 and 19, SEQ ID NOs: 15 and 16, or SEQ ID NOs: 21 and 22, each probe being 9-50 nucleotides in length; (3) a nucleic acid obtained from amplification of a Hepatitis B Virus nucleic acid template, containing the sequence selected from SEQ ID NOs: 15, 19, or 22, or its complementary sequence, the nucleic acid being 100-1,000 nucleotides in length.
| 2
|
CROSS REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not applicable.
FIELD OF THE INVENTION
This invention is directed to gels and composites made of polymers derived from naturally occurring sheet silicates, synthetic sheet silicates, naturally occurring tube silicates, and synthetic tube silicates.
BACKGROUND OF THE INVENTION
While U.S. Pat. No. 5,605,982 (Feb. 25, 1997) describes a process for making organopolysiloxane sheet or tube polymers by contacting a sheet or tube silicate with an alkenyl group containing chlorosilane to form an alkenylsiloxy polymer, it does not teach the reaction of a dihalosilane or a trihalosilane with a sheet silicate or a tube silicate, to produce sheet or tube-like organosiloxane polymers containing pendent groups of the particular type as described herein. The advantage of the pendent organofunctional group of the particular type described herein on such sheet or tube siloxane polymers is that it allows the sheets or tubes of the polymers to become crosslinked to gels and composite silicone matrices.
BRIEF SUMMARY OF THE INVENTION
The invention relates to gels and composites made from organopolysiloxane sheet or tube polymers which are prepared by contacting a sheet or tube silicate with an organohalosilane, in the presence of a polar solvent or in the presence of a mixture of a polar solvent and a non-polar solvent; and heating the resulting mixture of the sheet or tube silicate, the organohalosilane, and the solvent, until an organopolysiloxane sheet or tube polymer is formed.
The gels are prepared by mixing the organopolysiloxane sheet or tube polymer with an alkoxysilane, and allowing the mixture to stand at room temperature or above, for a time sufficient for gelation to occur.
The composites, i.e., articles of manufacture such as bulk composites, composite coatings and composite films, are prepared by exposing the gel to air, and allowing the gel to stand at room temperature or above, for a time sufficient for the gel to cure.
These and other features of the invention will become apparent from a consideration of the detailed description.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Not applicable.
DETAILED DESCRIPTION OF THE INVENTION
In particular, the present invention is directed to the preparation, characterization, and utilization of composite systems prepared from exfoliated sheet organofunctional siloxane polymers in silicone matrices. It is also particularly directed to the synthesis and utilization of composite systems from opened tube organofunctional siloxane polymers and silicone matrices. The sheet and tube polymers are derived from naturally occurring and synthetic sheet silicates and synthetic tube silicates.
For preparing the composite, the sheet or the tube organofunctional siloxane polymer is mixed at room temperature (about 20-25° C.) with a curable silicone matrix, e.g., an alkoxysilane, and then allowed to cure. The silicone matrix should be of a type possessing a strong intermolecular attraction with the sheet or tube polymer, so as to be sufficient to cause its exfoliation or opening. This process results in an increase in the viscosity of the matrix and the formation of a transparent, translucent or opaque gel.
Complete exfoliation of the sheet polymers can be deduced from the loss of the low angle powder X-ray diffractometry (XRD) reflection that characterizes interlayer spacing for sheet polymers. Strong intermolecular attraction between the matrix and the sheet or tube polymer can be provided by using materials having the same or similar organo groups.
For example, an apophyllite-derived bis-(3-cyanopropyl)hydroxysiloxy sheet polymer, or a 3-cyanopropylmethylhydroxysiloxy sheet polymer, can be exfoliated, and will readily form composites in alkoxysilanes such as 2-cyanoethyltrimethoxysilane, 2-cyanoethyltriethoxysilane, 3-cyanopropyltrimethoxysilane, 3-cyanopropyltriethoxysilane, 3-cyanopropylmethyldimethoxysilane, bis-(3-cyanopropyl)dimethoxysilane. (cyanomethylphenethyl)trimethoxysilane, and 11-cyanoundecyltrimethoxysilane.
While the type of silicone matrix preferred herein is a condensation cure system, such as described above, other curing systems typically employed in silicone technology can be used, including by means of example, hydrosilylation cure, photocure, free-radical cure, or peroxide cure systems providing the matrix has accessible silanol or alkoxy groups.
The composites are useful as films and coatings. The films and coatings can be used as gas barriers, as high temperature coatings, or as fire resistant materials. They are also useful as high strength monoliths due to the substantial or complete exfoliation of the sheet polymer or opening of the tube polymer. In addition, the materials are capable of functioning as components of sealant formulations, resin matrix composites, elastomers, and gels.
The sheet silicate most preferred to be used herein is the mineral apophyllite, KCa 4 Si 8 O 20 (F,OH).8H 2 O, while the most preferred tube silicate is a synthetic silicate K 2 CuSi 4 O 10 . Other natural and synthetic layered and tube silicates can also be used, such as magadiite, Na 2 Si 14 O 29 .7H 2 O; kenyaite, Na 2 Si 22 O 45 .9H 2 O; silinaite, NaLiSi 2 O 5 .2H 2 O; or chrysotile, Mg 3 (OH) 4 Si 2 O 5 .
The sheet silicate apophyllite KCa 4 Si 8 O 20 (F,OH).8H 2 O and other such silicates are commercially available, and may be purchased from supply houses such as Ward's Natural Science Establishment, Rochester, N.Y.; and Gelest, Tullytown, Pa.
Methods of preparing tube silicates such as K 2 CuSi 4 O 10 are described in various publications including U.S. Pat. No. 4,942,026 (Jul. 17, 1990); U.S. Pat. No. 5,605,982 (Feb. 25, 1997); U.S. Pat. No. 5,627,241 (May 6, 1997); Polymer Preprints (American Chemical Society, Division of Polymer Chemistry) Volume 32(3), Pages 508-509, (1991); and Colloids and Surfaces, Volume 63, Pages 139-149, (1992).
According to this invention, a typical synthesis involves the reaction of a halosilane, e.g., R 2 SiX 2 or RSiX 3 , with a sheet silicate or a tube silicate to produce a sheet-like or tube-like organosiloxane polymer that contains a pendent organofunctional group.
The halosilane is a dichlorosilane or a trichlorosilane represented by the formula R 1 R 2 SiCl 2 or R 1 SiCl 3 where R 1 and R 2 represent an alkyl group containing 1-30 carbon atoms; another type of non-reactive group such as an aryl group, an alkaryl group, or an aralkyl group; or a polar group such as cyanoalkyl. Most preferably, at least one R 1 or R 2 group in the halosilane is a polar group. Representative of other groups which can be used besides an alkyl group are aryl groups such as phenyl and xenyl; alkaryl (alkylaryl) groups such as tolyl and xylyl; and aralkyl (arylalkyl) groups such as benzyl, phenylethyl, and 2-phenylpropyl.
Some examples of suitable dichlorosilanes and trichlorosilanes are 2-cyanoethylmethyldichlorosilane, (NCCH 2 CH 2 )(CH 3 )SiCl 2 ; 3-cyanopropylmethyldichlorosilane, (NCCH 2 CH 2 CH 2 )(CH 3 )SiCl 2 ; 3-cyanopropylphenyldichlorosilane, (NCCH 2 CH 2 CH 2 )(C 6 H 5 )SiCl 2 ; bis-3-(cyanopropyl)dichlorosilane, (NCCH 2 CH 2 CH 2 ) 2 SiCl 2 ; 3-cyanobutylmethyldichlorosilane, (NCCH(CH 3 )CH 2 CH 2 )(CH 3 )SiCl 2 ; 2-cyanoethyltrichlorosilane, (NCCH 2 CH 2 )SiCl 3 ; 3-cyanopropyltrichlorosilane, (NCCH 2 CH 2 CH 2 )SiCl 3 ; and 3-cyanobutyltrichlorosilane, (NCCH(CH 3 )CH 2 CH 2 )SiCl 3 .
The reaction is carried out in the presence of a solvent. Representative polar solvents that are useful herein include N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 1-methyl-2-pyrrolidinone, and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU). The reaction can also be carried out in the presence of a mixture of a polar solvent and a non-polar solvent, such as a mixture of N,N-dimethylformamide and toluene, for example.
For convenience, the following abbreviations are used to identify the sheet polymers. Thus, A-C 2 H is used for the apophyllite-derived bis-(3-cyanopropyl)hydroxysiloxy sheet polymer having the formula [((NCC 3 H 6 ) 2 (HO)SiO) x (HO) 1-x SiO 1 .5 ] n ; while A-CMH is used for the apophyllite-derived 3-cyanopropylmethylhydroxysiloxy sheet polymer having the formula [((NCC 3 H 6 )(CH 3 )(HO)SiO) x (HO) 1-x SiO 1 .5 ] n .
In the formulas, the value of "x" can be determined by solid state nuclear magnetic resonance (NMR) experiments, and typically, x is equal to or less than about 0.60. However, a value for "n" is not determinable.
As used herein, the term "exfoliated" is intended to mean a substantial or complete separation or disassociation of the individual sheets of a sheet polymer, and the term "opened" is intended to mean a substantial or complete separation of the tubes of a tube polymer.
EXAMPLES
The following examples illustrate this invention in more detail as it relates to an A-CMH--(NCC 2 H 4 )Si(OCH 3 ) 3 composite.
Example 1
Synthesis of Apophyllite-Derived 3-Cyanopropylmethylhydroxysiloxy Sheet Polymer, [((NCC 3 H 6 )(CH 3 )(HO)SiO) x (HO) 1-x SiO 1 .5 ] n , A-CMH
A suspension of apophyllite (120 mesh, 3.0 g, 3.3 mmol), 3-cyanopropylmethyldichlorosilane (NCC 3 H 6 )(CH 3 )SiCl 2 (24 mL, 0.15 mol), and dimethylformamide (120 mL) was refluxed for 2.3 h and filtered. The solid was washed with hexane (150 mL), acetone (60 mL), a solution of water and acetone (1:1, 300 mL), and hexane (150 mL), dried (60 torr, 60° C.), and weighed (3.1 g). The following are the product powder X-ray diffractometry (XRD) data (d(Å) (I/I 0 )): 16.7 (100). The following are the product infrared (IR) spectroscopy data (evaporated acetone-gel coating on KBr, cm -1 ): 3446 (m br, H-bonded OH stretch), 2938 (m, CH stretch), 2890 (m, CH stretch), 2246 (m, CN stretch), 1456 (w), 1424 (m), 1350 (w, CH deformation), 1268 (s, SiC), 1058 (vs br, SiOSi stretch), 866 (w), 796 (s), 666 (w), 540 (w), 440 (s).
This synthesis of apophyllite-derived 3-cyanopropylmethylhydroxysiloxy sheet polymer, [((NCC 3 H 6 )(CH 3 )(HO)SiO) x (HO) 1-x SiO 1 .5 ] n , A-CMH, can be shown with reference to the following reaction:
KCa.sub.4 Si.sub.8 O.sub.20 (F,OH).8H.sub.2 O+(NCC.sub.3 H.sub.6)(CH.sub.3)SiCl.sub.2 →[((NCC.sub.3 H.sub.6)(CH.sub.3)(HO)SiO).sub.x (HO).sub.1-x SiO.sub.1.5 ].sub.n
Evidence for the formation of this A-CMH polymer as depicted above is provided by the presence of OH, CH, CN, and SiO bands in its infrared spectrum, and by the presence of a strong line in its X-ray powder pattern at 16.7 Å. The intensity and narrowness of the line in its powder pattern indicates that its sheets are quite planar and are stacked in orderly stacks.
Example 2
Gel
A mixture of A-CMH (0.16 g) and 2-cyanoethyltrimethoxysilane (NCC 2 H 4 )Si(OCH 3 ) 3 (1.9 g) was allowed to stand at room temperature for 1 day in a closed vial. The gel is cloudy and stiff.
Example 3
Bulk Composite
The A-CMH--(NCC 2 H 4 )Si(OCH 3 ) 3 gel prepared in Example 2 was exposed to air at room temperature for 3 days. The following are the product XRD data (d(Å) (I/I 0 )): 10.6 (100), 3.9 (br, 43). The bulk composite is a hard, white solid.
Example 4
Composite Coating
A thin layer of the A-CMH--(NCC 2 H 4 )Si(OCH 3 ) gel prepared in Example 2 was spread on a glass microscope slide, and exposed to air at room temperature for 1 day. The following are the product XRD data (d(Å) (I/I 0 )): 10.4 (100), 4.0 (br, 31). The composite coating is white and loosely adherent.
Example 5
Film Composite
A thin layer of the A-CMH--(NCC 2 H 4 )Si(OCH 3 ) 3 gel prepared in Example 2 was spread on a Teflon® sheet and exposed to air at room temperature for 1 day. The resulting film was then gently separated from the sheet. The following are the product XRD data (d(Å) (I/I 0 )): 10.4 (100), 3.9 (br, 50). The film is white and brittle.
Example 6
Physical Mixture for Comparison
(NCC 2 H 4 )Si(OCH 3 ) 3 (1.6 g) was exposed to air at room temperature for 4 days. The resulting white solid (0.95 g) was ground with a mortar and pestle, and the powder was mixed the A-CMH (81 mg). The following are the product XRD data (d(Å) (I/I 0 )): 17.0 (23), 10.4 (100), 4.0 (br. 24).
The absence of ˜17 Å line in the powder patterns of the bulk composite, the coating composite, and the film composite, and the presence of an ˜17 Å line in the patterns of A-CMH itself, and a mixture of A-CMH and cured (NCC 2 H 4 )Si(OCH 3 ) 3 (which had a smaller percentage of A-CMH than the composite), shows that the sheets of the A-CMH in the bulk composite, the coating composite, and the film composite are substantially or fully exfoliated.
Synthesis of the gel and the composite under very mild conditions, i.e., at room temperature and in the absence of an added catalyst, provides strong evidence that the sheets of the composite are not degraded.
Since the pendent groups on the sheets carry accessible silanol groups, it is believed that the sheets become crosslinked to the composite matrix. A curing reaction leading to the composite can be approximated as shown below: ##STR1##
The hardness of the resulting composite can be attributed to the three-dimensional crosslinking present in the composite. The white color of the composite is ascribed to a mismatch between the index of refraction of A-CMH and the matrix.
The ability of (NCC 2 H 4 )Si(OCH 3 ) 3 to form such a composite is attributed to the polyfunctional nature of this particular silane. In this regard, the nitrile functionality provides the silane with the ability to serve as an effective exfoliating agent, while the three methoxysilane functionalities provide the silane with the ability to serve as an effective crosslinking agent. Noteworthy for this silane are the mildness of the conditions required for both gel formation and for gel curing.
Since the conversion of the gel to the composite involves only the loss of CH 3 OH, and not loss of the whole silane, the composite is compact and is not an aerogel.
The following additional examples are set forth for the purpose of illustrating the invention in still more detail as it relates to an A-CMH--(NCC 3 H 6 )(CH 3 )Si(OCH 3 ) 2 composite.
Example 7
Synthesis of Apophyllite-Derived 3-Cyanopropylmethylhydroxysiloxy Sheet Polymer, [((NCC 3 H 6 )(CH 3 )(HO)SiO) x (HO) 1-x SiO 1 .5 ] n , A-CMH
A-CMH was made as described above in Example 1.
Example 8
Gel
A mixture of A-CMH (0.15 g) and 3-cyanopropylmethyldimethoxysilane (NCC 3 H 6 )Si(CH 3 )(OCH 3 ) 2 (0.85 g) was allowed to stand at room temperature for 1 day in a closed vial. The gel is cloudy and stiff.
Example 9
Bulk Composite
The A-CMH--(NCC 3 H 6 )(CH 3 )Si(OCH 3 ) 2 gel prepared in Example 8 was exposed to air for 4 days. The following are the product XRD data (d(Å) (I/I 0 )): 10.4 (100), 4.0 (br, 33). The bulk composite is cloudy and relatively pliable.
The absence of ˜17 Å line in the powder pattern of the bulk composite and the presence of such a line in the pattern of the A-CMH composition leads to the conclusion that the sheets in the bulk composite are substantially or completely delaminated. The mild conditions used for the preparation of the gel and the composite suggest that the sheets in the gel and in the composite are not degraded. An approximation of the composite crosslinking reaction is shown below: ##STR2##
Cloudiness in the appearance of this composite is ascribed to a refractive index mismatch, as noted above. The pliability of the composite is attributed to the presence of two, rather than three, methoxy groups in the matrix forming the silane, as this factor leads to less crosslinking. Again, the ease of synthesis of the composite is notable.
The following further examples are set forth for the purpose of illustrating the invention in yet more detail as it relates to an A-C 2 H--(NCC 2 H 4 )Si(OCH 3 ) 3 composite.
Example 10
Synthesis of Apophyllite-Derived Bis-(3-cyanopropyl)hydroxysiloxy Sheet Polymer, [((NCC 3 H 6 ) 2 (HO)SiO) x (HO) 1-x SiO 1 .5 ] n , A-C 2 H
A suspension of apophyllite (120 mesh, 1.2 g, 1.3 mmol), bis-(3-cyanopropyl)dichlorosilane (NCC 3 H 6 ) 2 SiCl 2 (10 mL, 50 mmol), and dimethylformamide (20 mL), was refluxed for 1.5 h and filtered. The solid was washed with hexane (60 mL), acetone (30 mL), a solution of water and acetone (1:1, 100 mL), and hexane (60 mL), air-dried, and weighed (1.24 g). The following are the product XRD data (d(Å) (I/I 0 )): 17.6 (100). The following are the product infrared (IR) spectroscopy data (evaporated acetone-gel coating on KBr, cm -1 ): 3384 (s br, H-bonded OH stretch), 2938 (s, CH stretch), 2884 (m, CH stretch), 2246 (s, CN stretch), 1454 (w), 1424 (m), 1352 (w), 1066 (vs br, SiOSi stretch), 866 (w), 786 (s), 442 (s).
This synthesis of apophyllite-derived bis-(3-cyanopropyl)methylhydroxysiloxy sheet polymer, [((NCC 3 H 6 ) 2 (HO)SiO) x HO) 1-x SiO 1 .5 ] n , A-C 2 H, is similar to that of the synthesis of A-CMH shown previously. The reaction can be depicted as shown below:
KCa.sub.4 Si.sub.8 O.sub.20 (F,OH).8H.sub.2 O+(NCC.sub.3 H.sub.6).sub.2 SiCl.sub.2 →[((NCC.sub.3 H.sub.6).sub.2 (HO)SiO).sub.x (HO).sub.1-x SiO.sub.1.5 ].sub.n
Evidence for the formation of this A-C 2 H polymer is provided by the presence of strong OH, CH, CN, and SiO bands in its infrared spectrum, and by the presence of a line in its X-ray powder pattern at 17.6 Å. The considerable intensity of its powder pattern line indicates that the sheets of the polymer are quite planar, and that they are stacked in an orderly fashion.
Example 11
Gel
A mixture of A-C 2 H (0.14 g) and 2-cyanoethyltrimethoxysilane, (NCC 2 H 4 )Si(OCH 3 ) 3 , (1.5 g) was allowed to stand at room temperature for 1 day in a closed vial. The gel is cloudy and stiff.
Example 12
Bulk Composite
The A-C 2 H--NCC 2 H 4 Si(OCH 3 ) 3 gel prepared in Example 11 was exposed to air at room temperature for 3 days. The following are the product XRD data (d(Å) (I/I 0 )): 10.5 (100), 3.9 (br, 35). The bulk composite is a hard, white solid.
Example 13
Physical Mixture for Comparison
(NCC 2 H 4 )Si(OCH 3 ) 3 (2.5 g) was exposed to air at room temperature for 3 days. The resulting solid was ground and the powder was mixed with A-C 2 H (0.14 g). The following are the product XRD data (d(Å) (I/I 0 )): 17.0 (23), 10.4 (100), 4.0 (br, 24).
The presence of a clear ˜17 Å line in the powder pattern of the physical mixture, but not in that of the composite, provides evidence that the composite contained nearly fully or fully delaminated sheets. The absence of an ˜17 Å line in the powder pattern of the bulk composite, and the presence of such a line in the pattern of the A-C 2 H composition itself, and the mixture of A-C 2 H and cured (NCC 2 H 4 )Si(OCH 3 ) 3 (which had a lower percentage of A-C 2 H than the composite) leads to the conclusion that the sheets in the bulk composite are substantially or fully delaminated. The synthesis of the gel and the synthesis of the composite under very mild conditions indicates that sheets of the gel and the sheets of the composite are not degraded. The composite curing reaction can be approximated as shown below: ##STR3##
The hardness and the color of this composite can be explained the same as for the composite made from the A-CMH--(NCC 2 H 4 )Si(OCH 3 ) 3 gel noted above. The mildness of the conditions required for the formation of the gel and for the formation of the composite are noteworthy.
These examples demonstrate that certain alkoxysilanes are capable of yielding fully exfoliated, compact composites, with A-CMH and with A-C 2 H.
Other variations may be made in compounds, compositions, and methods described herein, without departing from the essential features of the invention. The embodiments specifically illustrated herein are exemplary only, and not intended as limitations on their scope, except as defined in the appended claims.
|
Articles of manufacture, such as bulk composites, composite coatings, and composite films, can be prepared by exposing a gel to air, and allowing it to stand at room temperature to cure. The gel is obtained by mixing an organopolysiloxane sheet or tube polymer with an alkoxysilane. Organopolysiloxane sheet or tube polymers are obtained by contacting sheet or tube silicates with an organohalosilane and a solvent, and heating the mixture.
| 2
|
FIELD OF INVENTION
The present invention is related to a method for printing gradient images using phase change ink with discrete drop size. More specifically, the present invention is related to an apparatus and method for printing an image with a high gradient and excellent resolution without substantial compromises in physical stability of the image.
BACKGROUND OF THE INVENTION
Many methods have been proposed for the generation of gradient images from discrete dots of ink.
Combinations of different density solvent based inks in an ink jet printing method have been shown to be a suitable approach to the generation of high gradient images from a discrete number of inks. U.S. Pat. Nos. 4,727,436; 4,860,026; 5,142,374; 4,713,746; and 4,713,701 all teach variations on methods and apparatus for combining inks. Suitable gradients are available using these and other techniques. Even with suitable gradients the image quality is still unsuitable due to image dot spreading which occurs as a result of the carrier solvent, such as water or an organic, and the ink diffusing into the media. Another major disadvantage of solvent based ink jet systems is the solvent which must be absorbed by the media or evaporated after printing. Evaporation of the solvent is environmentally unsatisfactory particularly when non-aqueous solvents are employed. It has been a long standing goal of skilled artisans to decrease the amount of ink used to form an image which, in-turn, decreases the image dot spread and lowers cost.
Phase change ink printing provides some advantages over solvent based ink jet systems. Specifically, there is no solvent since the phase change ink is a solid at room temperature and a liquid at coating temperatures. One disadvantage of phase change ink printing is the inability to easily vary drop size on demand. Discrete drop sizes limit the gradient levels available with conventional phase change ink printing methods due to the lack of continuously variable ink density levels. Phase change ink printing does allow for the placement of multiple dots at a given position which increases the contrast available to some extent. When multiple dots are applied image resolution and image durability deteriorate due to the appearance of ink islands occurring as a result of the stacking of solid ink. Phase change inks and printing techniques are described, for instance, in U.S. Pat. Nos. 5,372,852 and 5,276,468 and in European Patent Applications 0 566 259 and 0 604 025.
It would be highly advantageous to combine the dry printing capabilities of phase change ink printing with the ink combining methods of solvent based ink jet printing to achieve a superior print with high resolution and contrast. Efforts towards this goal have been thwarted and the method has been considered to be abandoned by skilled artisans due to the loss of resolution and poor image durability resulting from the ink islands.
The present invention provides a method for eliminating the problems associated with combining phase change inks of different densities. The resulting image exhibits excellent gradation without discontinuities and provides a superior method of printing.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a printing system which provides an image with the appearance of continuous gradients from discrete ink drops.
It is another object of the present invention to provide an imaging system which is durable and less susceptible to physical deterioration resulting from abrasion.
It is yet another object of the present invention to provide an imaging system which does not require the absorption, or evaporation of solvents.
These and other advantages, as will be apparent, are provided in an apparatus for recording a gradient image on transparent media comprising: at least one solid phase change ink; a solid null image element; a heating system capable of melting the solid phase change ink to form a molten phase change ink and capable of melting the solid null image element to form a molten null image element; a printing head capable of receiving the molten phase change ink and the molten null image element and depositing them in an imagewise pattern onto a transfer surface; a transfer surface capable of receiving the imagewise pattern; a cooling mechanism for cooling the molten phase change ink and the molten null image element in the imagewise pattern to form a malleable phase change ink and a malleable null image element in the imagewise pattern on the transfer surface; a media; a transfer mechanism capable of transferring said malleable phase change ink and said malleable null image element in said imagewise pattern on said transfer surface to said media.
A particularly preferred embodiment is provided in an apparatus for recording a gradient image on media comprising: a set of solid phase change inks comprising: a first solid phase change ink with an optical density defined by the formula:
P.sub.1 ≦N.sub.a ·n·m·P.sub.n +D;
a second solid phase change ink with an optical density (P 2 ) defined by the formula:
P.sub.2 ≦N.sub.a ·n·m·P.sub.n +N.sub.1 ·n·m·P.sub.1 +D; and
a third imaging ink has an optical density (P 3 ) defined by the formula:
P.sub.3 ≦N.sub.a n·m·P.sub.n +N.sub.1 ·n·m·P.sub.1 +N.sub.2 ·n·m·P.sub.2 +D;
a solid null image element;
a heating system capable of melting the set of solid phase change inks to form a set of molten phase change inks and melting the solid null image element to form a molten null image element; a printing head capable of receiving the set of molten phase change inks and the molten null image element and depositing the set of molten phase change inks and the molten null image element in a molten imagewise pattern; a transfer surface capable of receiving the molten imagewise pattern from the printing head; a cooling mechanism for cooling said molten imagewise pattern to form a malleable imagewise pattern on the transfer surface; a media; and a transfer mechanism capable of transferring the malleable imagewise pattern to the media.
Another preferred embodiment is provided in an apparatus for recording a gradient image on media comprising: a set of solid phase change inks comprising: a first solid phase change ink with an optical density of at least 0.08 to no more than 0.40 for a 19 μm thick drop; a second solid phase change ink has an optical density has an optical density of more than 0.40 to no more than 0.90 for a 19 μm thick drop; a third imaging ink has an optical density of at least 1.2 to 5.0 for a 19 μm thick drop; a solid null image element wherein said null image element has an optical density of less than 0.15 for a 19 μm thick drop; a heating system capable of melting said set of solid phase change inks to form a set of molten phase change inks and melting said solid null image element to form a molten null image element; a printing head capable of receiving said set of molten phase change inks and said molten null image element and depositing said set of molten phase change inks and said molten null image element in a molten imagewise pattern; a transfer surface capable of receiving said molten imagewise pattern from said printing head; a cooling mechanism for cooling said molten imagewise pattern to form a malleable imagewise pattern on said transfer surface; a media; and a transfer mechanism capable of transferring said malleable imagewise pattern on said transfer surface to said media.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of the phase change printing apparatus.
FIG. 2 is an enlarged diagrammatic illustration of the phase change ink on the liquid layer intermediate transfer surface.
FIG. 3 is an enlarged diagrammatic illustration of the prior art transfer of the phase change ink image onto the media.
FIG. 4 is an enlarged diagrammatic illustration of the transfer of the phase change ink image onto the media in accordance with the present invention.
FIG. 5 shows a response curve of optical density versus ink level for Comparative Case # 1.
FIG. 6 shows a response curve of optical density versus ink level for Inventive Case # 2.
DETAILED DESCRIPTION OF THE INVENTION
Throughout the following descriptions similar elements are so numbered in the figures.
FIG. 1 is a diagrammatic illustration of the phase change printing apparatus and FIG. 2 is an enlargement illustrating a single ink droplet on the surface of the liquid layer. In FIG. 1 the system, generally referred to as 1, comprises a printhead, 2. The ink is melted from the solid form to a molten state by the application of heat energy to raise the temperature to a level of from about 85° C. to about 150° C. Temperatures above 150° C. are avoided due to the onset of degradation of the ink by chemical breakdown. The molten ink is expelled as a droplet, 3, to the exposed surface of the liquid layer, 4. The liquid layer forms the intermediate transfer surface on the drum, 8. The liquid layer is applied by an applicator, 12, connected to a web applicator support, 13, contained within retractable applicator apparatus, 14. The molten ink is cooled to an intermediate temperature and solidified to a malleable state seen as ink drop, 5, of FIG. 2. The intermediate temperature where the solidified ink is maintained in its malleable state is preferably between about 30° C. and about 80° C. The ink drop is then transferred to the media, 6, via a contact transfer by entering the nip between the fusing roller, 7, and the liquid layer, 4. A stripper, 16, only one of which is shown, assist in stripping the media from the liquid layer.
Once the malleable ink image enters the nip it adheres, or is fixed, to the media, 6, either by the pressure exerted against the ink image on the media, 6, or by the pressure exerted by the fusing roller, 7, or by the combination of the pressure and heat supplied by an optional heating apparatus, 9. Additional heating apparatus, 10 and 11, could optionally be employed to supply heat to facilitate the process of transferring the malleable ink to the media. The media is directed with the assistance of a guide, 15.
The pressure exerted on the ink image is between about 10 to about 2000 pounds per square inch (psi), more preferably between about 750 psi to about 850 psi. The pressure must be sufficient to have the ink image adhere to the media, 6, and be sufficiently deformed to ensure that light is transmitted through the ink rectilinearly or without significant deviation in its path from the inlet to the outlet. This is particularly important in the present invention since a major advantage of the present invention is the ability to print on transparency media. Once the ink is adhered to the media the ink image is cooled to ambient temperature of about 20° C. to about 25° C. The ink comprising the image must be ductile, or be able to yield or experience plastic deformation without fracture when kept above the transition temperature. Below the glass transition temperature the ink is brittle. The temperature of the ink image in the ductile state is between -10° C. and about the melting point, or less than about 85° C.
FIG. 3 is an enlarged diagram illustrating the transfer of inked image from the liquid transfer surface to the media as employed in the prior art. In FIG. 3, the ink drop is deformed to its final conformation, 17. Each addressable location is defined as a subpixel. A multiplicity of subpixels are taken together to define a superpixel. It is apparent in FIG. 3 that the ink image comprises a relief, 18, the thickness of which depends on the amount of ink deposited on the media. If the thickness of the relief becomes to large the ink image becomes unstable and the resolution deteriorates due to collapsing of the relief and spreading of the phase change ink over a larger area. Yet another problem with the relief is the integrity of the image. The relief edge increases the mechanical stresses to which the ink image are susceptible and stripping the ink image from the media commonly results with abrasion. Prior art printing procedures limited the thickness of the relief to decrease the detrimental effects of relief destruction and degradation.
If multiple drops of ink are applied to the media in a single location the thickness of the relief image increases in proportion to the number of drops which exaggerates the problems described previously.
The present invention solves these problems and provides a printing method which allows for the use of multiple density inks which can be combined to form a gradient image.
FIG. 4, illustrates an embodiment of the present invention wherein the image element, 19, is stabilized by null image elements 20, deformed to the transparent image, 21. The null image element removes the relief and stabilizes the image element, 19, from the problems associated with relief destruction. The null image element also increases the apparent image quality due to the reduction in image parallax. The effect of image parallax on image quality was previously not appreciated.
By incorporating an additional null image element the thickness of the image can be increased while, at the same time, avoiding the problems associated with relief images.
The size of the phase change ink drop is chosen as a compromise between printing efficiency and resolution. A large drop tends towards increasing printing efficiency at the expense of resolution and a smaller drop tends towards increasing resolution at the expense of printing efficiency. Another concern is the degree of deformation of the phase change ink drop in the nip as the phase change ink is adhered to the surface of the media. Preferably, the phase change ink drop is between 10 nanograms and 150 nanograms in mass. Most preferably the phase change ink drop is 20-50 nanograms in mass. For the purposes of comparison a 35 nanogram phase change ink drop, with a density (g/ml) of approximately 1.0, printed to a resolution of 600 drops per inch by 600 drops per inch will have a thickness of approximately 19 μm. For purposes of clarity the optical density will be reported herein for a phase change ink drop of 19 μm. The optical density for other thicknesses can be determined using Beers Law. Beers Law applies to transmitted images printed in the manner described herein. All optical densities reported herein are specifically transmitted optical densities.
The null image element is characterized as a phase change ink which is substantially void of colorants, or pigmentation as represented by an optical density. For the purposes of definition the term "substantially void of colorants, or pigmentation as represented by optical density" refers specifically to a phase change ink wherein the optical density of a 19 μm thick drop is less than 0.15. More preferably, the null image element has an optical density of less than 0.1 for a 19 μm thick drop and most preferably the null image element has an optical density of less than 0.075 for a 19 μm thick drop.
The null image element is applied to the media at any point characterized in the print algorithm as void of ink or those areas corresponding to minimum optical density. In the present invention the entire image is preferably printed with some combination of null image element for the low optical density regions and imaging inks for the high optical density regions. It is preferred that at least 70% of the image area is printed. Preferably at least 85% of the image area is printed and most preferably at least 95% of the image area is printed. It is preferable that the null image element is used to fill the image such that no two adjacent subpixels differ in thickness by more than the thickness of two phase change ink drops. More preferably, the null image element is used to fill the image such that no two adjacent subpixels differ in thickness by more than the thickness of one phase change ink drop.
It is conventional in the art to utilize a multiplicity of jets in the formation of an image. Each jet utilizes a unique phase change ink with a specific optical density. For the purposes of the present invention it is contemplated that at least three jets, more preferably four, will be employed in a phase change ink printer with one jet printing the null image element and two jets, or more preferably three, printing different density inks to achieve a gradient image. In practice, each jet typically prints one drop per subpixel per pass. Therefore, for a conventional configuration with four ink jets as many as four drops of ink can be deposited on a single subpixel in a single pass. For convenience, and printing efficiency, it is preferred that only two drops be deposited in a single subpixel which decreases the choice of ink optical densities which can be successfully employed. It is critical in high quality imaging to avoid discontinuities in the gradient. The choice of ink optical densities is also limited by the demand to generate a continuous gradient scale defined as a scale with a maximum deviation between adjacent optical densities of no more than 0.01. A deviation between adjacent optical densities of more than 0.01 becomes observable to the naked eye and does not appear as a continuous gradient image. More preferably, the maximum deviation between adjacent optical densities is no more than 0.008 and most preferably no more than 0.005 at low optical densities.
Taking the image limitations into consideration the optical densities of the imaging inks are bound by the following embodiments.
Preferably, the imaging inks comprise a first imaging ink, a second imaging ink and a third imaging ink. The first imaging ink preferably has an optical density of at least 0.08 and no more than 0.40 for a 19 μm thick drop. More preferably the first imaging ink has an optical density of at least 0.20 and no more than 0.40 for a 19 μm thick drop. The second imaging ink preferably has an optical density of more than 0.40 and no more than 0.90 for a 19 μm thick drop. More preferably the second imaging ink has an optical density of more than 0.70 and no more than 0.90 for a 19 μm thick drop. The third imaging ink preferably has an optical density of at least 1.2 to 5.0 for a 19 μm thick drop and more preferably the third imaging ink has an optical density of at least 1.2 to 2.0 for a 19 μm thick drop. To avoid discontinuities in the gradients each subsequent imaging ink must be able to provide a density which overlaps with the density available from the imaging inks of lower density. When a dither pattern is used each subsequent ink can be no higher in optical density than the optical density of a single drop divided by the dither matrix size.
By way of example; a first imaging ink with an optical density of 0.3 at a given drop size, used in a 2×2 dither matrix, with two passes can provide an optical density up to 0.6. In this example, each subpixel of the 2×2 dither matrix would comprise two drops of the first imaging ink. A second imaging ink would have to be able to provide a density of 0.6±maximum deviation between adjacent densities. Since the densities of the four subpixels of a 2×2 dither matrix are averaged to obtain the density of the superpixel a single drop in one subpixel of the 2×2 dither matrix would be restricted to a density of no more than 4 times the minimum density or 2.4 since averaging a single dot of density 2.4 over four subpixels would provide a density for the superpixel of 0.6.
In general, the determination of imaging ink densities can be determined by the following algorithms taking into consideration the following terms.
D is the maximum deviation between optical density steps allowable;
P n is the optical density of the null image element;
N a is the number of ink drops allowed per subpixel for each ink (a); and
n and m taken together multiplicitivly define the number of subpixels per superpixel.
For the first imaging ink the optical density (P 1 ) is chosen as:
P.sub.1 ≦N.sub.a ·n·m·P.sub.n +D
For the second imaging ink the optical density (P 2 ) is chosen as:
P.sub.2 ≦N.sub.a ·n·m·P.sub.n +N.sub.1 ·n·m·P.sub.1 +D.
For the third imaging ink the optical density (P 3 ) is chosen as:
P.sub.3 ≦N.sub.a ·n·m·P.sub.n +N.sub.1 ·n·m·P.sub.1 +N.sub.2 ·n·m·P.sub.2 +D.
Phase change inks are characterized, in part, by their propensity to remain in the solid phase at ambient temperature and in the liquid phase at elevated temperatures in the printing head. The ink is heated to form the liquid phase and droplets of liquid ink are ejected from the printing head onto the transfer surface. The transfer surface is maintained at a temperature which is suitable for maintaining the phase change ink in a rubbery, or malleable state. The ink droplets are then transferred to the surface of the printing media and the phase change ink is allowed to solidify to form a pattern of solid ink drops.
Exemplary phase change ink compositions comprise the combination of a phase change ink carrier and a compatible colorant.
Exemplary phase change ink colorants comprise a phase change ink soluble complex of (a) a tertiary alkyl primary amine and (b) dye chromophores having at least one pendant acid functional group in the free acid form. Each of the dye chromophores employed in producing the phase change ink colorants are characterized as follows: (1) the unmodified counterpart dye chromophores employed in the formation of the chemical modified dye chromophores have limited solubility in the phase change ink carrier compositions, (2) the chemically modified dye chromophores have at least one free acid group, and (3) the chemically modified dye chromophores form phase change ink soluble complexes with tertiary alkyl primary amines. For example, the modified phase change ink colorants can be produced from unmodified dye chromophores such as the class of Color Index dyes referred to as Acid and Direct dyes. These unmodified dye chromophores have limited solubility in the phase change ink carrier so that insufficient color is produced from inks made from these carriers. The modified dye chromophore preferably comprises a free acid derivative of a xanthene dye.
The tertiary alkyl primary amine typically includes alkyl groups having a total of 12 to 22 carbon atoms, and preferably from 12 to 14 carbon atoms. The tertiary alkyl primary amines of particular interest are produced by Rohm and Haas Texas, Incorporated of Houston, Tex. under the tradenames Primene JMT and Primene 81-R. Primene 81-R is a particularly suitable material. The tertiary alkyl primary amine of this invention comprises a composition represented by the structural formula: ##STR1## wherein: x is an integer of from 0 to 18;
y is an integer of from 0 to 18; and
z is an integer of from 0 to 18;
with the proviso that the integers x, y and z are chosen according to the relationship:
x+y+z=8 to 18.
An exemplary phase change ink carrier comprises a fatty amide containing material. The fatty amide-containing material of the phase change ink carrier composition may comprise a tetraamide compound. Particularly suitable tetra-amide compounds for producing phase change ink carrier compositions are dimeric acid-based tetra-amides including the reaction product of a fatty acid, a diamine such as ethylene diamine and a dimer acid. Fatty acids having from 10 to 22 carbon atoms are suitable in the formation of the dimer acid-based tetra-amide. These dimer acid-based tetramides are produced by Union Camp and comprise the reaction product of ethylene diamine, dimer acid, and a fatty acid chosen from decanoic acid, myristic acid, stearic acid and docosanic acid. Dimer acid-based tetraamide is the reaction product of dimer acid, ethylene diamine and stearic acid in a stoichiometric ratio of 1:2:2, respectively. Stearic acid is a particularly suitable fatty acid reactant because its adduct with dimer acid and ethylene diamine has the lowest viscosity of the dimer acid-based tetra-amides.
The fatty amide-containing material can also comprise a mono-amide. The phase change ink carrier composition may comprise both a tetra-amide compound and a mono-amide compound. The mono-amide compound typically comprises either a primary or secondary mono-amide. Of the primary mono-amides stearamide, such as Kemamide S, manufactured by Witco Chemical Company, can be employed herein. The mono-amides behenyl behemamide and stearyl stearamide are extremely useful secondary mono-amides. Stearyl stearamide is the mono-amide of choice in producing a phase change ink carrier composition.
Another way of describing the secondary mono-amide compound is by structural formula. More specifically, the secondary mono-amide compound is represented by the structural formula:
C.sub.x H.sub.y --CO--NHC.sub.a H.sub.b
wherein:
x is an integer from 5 to 21;
y is an integer from 11 to 43;
a is an integer from 6 to 22; and
b is an integer from 13 to 45.
The fatty amide-containing compounds comprise a plurality of fatty amide materials which are physically compatible with each other. Typically, even when a plurality of fatty amide-containing compounds are employed to produce the phase change ink carrier composition, the carrier composition has a substantially single melting point transition. The melting point of the phase change ink carrier composition is most suitably at least about 70° C.
The phase change ink carrier composition may comprise a tetra-amide and a mono-amide. The weight ratio of the tetraamide to the mono-amide is from about 2:1 to 1:10.
Modifiers such as tackifiers and plasticizers may be added to the carrier composition to increase the flexibility and adhesion. The tackifiers of choice are compatible with fatty amide-containing materials. These include, for example, Foral 85, a glycerol ester of hydrogenated abietic acid, and Foral 105, a pentaerythritol ester of hydroabietic acid, both manufactured by Hercules Chemical Company; Nevtac 100 and Nevtac 80 which are synthetic polyterpene resins manufactured by Neville Chemical Company; Wingtack 86, a modified synthetic polyterpene resin manufactured by Goodyear Chemical Company, and Arakawa KE 311, a rosin ester manufactured by Arakawa Chemical Company. Arakawa KE 311, is a particularly suitable tackifier for use phase change ink carrier compositions.
Plasticizers may be added to the phase change ink carrier to increase flexibility and lower melt viscosity. Plasticizers which have been found to be advantageous in the composition include dioctyl phthalate, diundecyl phthalate, alkylbenzyl phthalate (Santicizer 278) and triphenyl phosphate, all manufactured by Monsanto Chemical Company; tributoxyethyl phosphate (KP-140) manufactured by FMC Corporation; dicyclohexyl phthalate (Morflex 150) manufactured by Morflex Chemical Company Inc.; and trioctyl trimellitate, manufactured by Kodak. However, Santicizer 278 is a plasticizer of choice in producing the phase change ink carrier composition.
Other materials may be added to the phase change ink carrier composition. In a typical phase change ink carrier composition antioxidants are added for preventing discoloration. Antioxidants include Irganox 1010, manufactured by Ciba Geigy, Naugard 76, Naugard 512, and Naugard 524, all manufactured by Uniroyal Chemical Company.
A particularly suitable phase change ink carrier composition comprises a tetra-amide and a mono-amide compound, a tackifier, a plasticizer, and a viscosity modifying agent. The compositional ranges of this phase change ink carrier composition are typically as follows: from about 10 to 50 weight percent of a tetraamide compound, from about 30 to 80 weight percent of a mono-amide compound, from about 0 to 25 weight percent of a tackifier, from about 0 to 25 weight percent of a plasticizer, and from about 0 to 10 weight percent of a viscosity modifying agent.
The transmission spectra for each of the phase change inks can be evaluated on a commercially available spectrophotometer, the ACS Spectro-Sensor II, in accordance with the measuring methods stipulated in ASTM E805 (Standard Practice of Instrumental Methods of Color or Color Difference Measurements of Materials) using the appropriate calibration standards supplied by the instrument manufacturer. For purposes of verifying and quantifying the overall calorimetric performance, measurement data are reduced, via tristimulus integration, following ASTM E308 (Standard Method for Computing the Colors of Objects using the CIE System) in order to calculate the 1976 CIE L* (Lightness), a* (redness-greeness), and b* (yellownessblueness), (CIELAB) values for each phase change ink sample. In addition, the values for CIELAB Psychometric Chroma, C* sub ab, and CIELAB Psychometric Hue Angle, h sub ab were calculated according to publication CIE 15.2, Colorimetry (Second Edition, Central Bureau de la CIE, Vienna, 1986).
The nature of the phase change ink carrier composition is chosen such that thin films of substantially uniform thickness exhibit a relatively high L* value. For example, a substantially uniform thin film of about 20-70 μm thickness of the phase change ink carrier preferably has an L* value of at least about 65.
The phase change ink carrier composition forms an ink by combining the same with a colorant. A subtractive primary colored phase change ink will be formed by combining the ink carrier composition with compatible subtractive primary colorants. The subtractive primary colored phase change inks comprise four component dyes, namely, cyan, magenta, yellow and black. The subtractive primary colorants comprise dyes from either class of Color Index (C.I.) Solvent Dyes and Disperse Dyes. Employment of some C.I. Basic Dyes can also be successful by generating, in essence, an in situ Solvent Dye by the addition of an equimolar amount of sodium stearate with the Basic Dye to the phase change ink carrier composition. Acid Dyes and Direct Dyes are also compatible to a certain extent.
The phase change inks formed therefrom have, in addition to a relatively high L* value, a relatively high C* ab value when measured as a thin layer of substantially uniform thickness as applied to a substrate. A reoriented layer of the phase change ink composition on a substrate has a C* ab value, as a substantially uniform thin film of about 20 μm thickness, of subtractive primary yellow, magenta and cyan phase change ink compositions, which are at least about 40 for yellow ink compositions, at least about 65 for magenta ink compositions, and at least about 30 for cyan ink compositions.
The thickness of the liquid layer forming the intermediate transfer surface on the drum can be measured, such as by the use of reflectance Fourier Transform infrared spectroscopy or a laser interferometer. It is theorized that the thickness can vary from about 0.05 microns to about 60 microns, most preferably, from about 1 micron to about 10 microns. The thickness of the layer forming the intermediate transfer surface can increase if rougher surfaced supporting surfaces or drums are employed. The surface topography of the supporting surface or drum can have a roughness average (R n ) of from about 1 microinch to about 100 microinchs and more preferably from about 5 to about 15 microinches.
Suitable liquids that may be employed as the intermediate transfer surface include water, fluorinated oils, glycol, surfactants, mineral oil, silicone oil, functional oils, such as mercaptosilicone oils, fluorinated silicone oils and the like, or combinations thereof.
The following examples are illustrative of the invention and are not intended to limit the invention in any manner.
EXAMPLES
The following cases demonstrate the gray levels available given a wherein the superpixel is defined by four subpixels in a 2×2 arrangement. Single layer ink optical densities of 0.02, 0.08, 0.36 and 1.6 are employed in both cases. The maximum optical density is reached with two drop of the highest density and one drop of the next highest density in a single subpixel.
Comparative Case #1
The null image element is not used for full coverage. The highest optical density is achieved with two drops of the highest density ink and one drop of the next highest density in a single subpixel. A theoretical total of 440 unique gray levels are achieved, however, in practice the gray level are not achieved because this requires placement of subpixels with no ink next to subpixels with three drops of ink. In this comparative case the relief is large and the collapses and spreads. This would especially be noticed in the ability to hold line of minimum density in a field of maximum density. This case yields totally unsatisfactory results due to the loss of gradient and the loss of qualititative image quality. FIG. 5 illustrates optical density versus ink level for the comparative case.
Inventive Case #2
The inventive case differs from Comparative Case #1 by the use of the null image element which is used to obtain full coverage, even in large areas of minimum density. In this case fewer theoretical levels, a total of 405, are achieved, however, all of these levels are usable in forming an image. The thickness of ink layers differs by no more than two ink drop thicknesses in any adjacent subpixels. Collapse of the relief and dot spread are much improved relative to Comparative Case #1. A thin line of minimum density on a maximum density filed will hold. Although the theoretical number of gray levels may be decreased, the practical number of usable gray levels will be much higher. FIG. 6 illustrates optical density versus ink level for the inventive case.
Comparative Case #1 and Inventive Case #2 both illustrate suitable gradient response curves as illustrated in FIGS. 5 and 6. Comparative Case #1 provides an image quality which is unacceptable while Inventive Case #2 provides an image quality which is superior with highly resolved edges.
|
The present invention describes an apparatus for recording a gradient image on transparent media comprising: at least one solid phase change ink; a solid null image element; a heating system capable of melting the solid phase change ink to form a molten phase change ink and capable of melting the solid null image element to form a molten null image element; a printing head capable of receiving the molten phase change ink and the molten null image element and depositing them in an imagewise pattern onto a transfer surface; a transfer surface capable of receiving the imagewise pattern; a cooling mechanism for cooling the molten phase change ink and the molten null image element in the imagewise pattern to form a malleable phase change ink and a malleable null image element in the imagewise pattern on the transfer surface; a media; a transfer mechanism capable of transferring said malleable phase change ink and said malleable null image element in said imagewise pattern on said transfer surface to said media.
| 1
|
BACKGROUND
The invention relates to a method for treating threads on spools which can be worked with the above-defined installation, and which comprises impregnating in cool condition the spooled thread with a treatment liquid inside a kier, discharging said liquid from the kier, and treating the spooled threads with steam inside said kier.
THE INVENTION
According to the invention, the impregnating is performed by leaving an air cushion above the liquid inside said kier, and the liquid is discharged from the kier by feeding steam above said air cushion, said discharge being stopped as the steam reaches the liquide discharge outlet.
In an advantageous embodiment of the invention, the steam treatment is regulated for a pre-determined time interval from that moment where a determined temperature is reached inside a spooled thread.
Other details and features of the invention will stand out from the following description of a method for bleaching and dyeing spooled threads, according to the invention, given hereinafter by way of non limitative example and with reference to the accompanying drawings, in which:
THE DRAWINGS
FIG. 1 is a diagrammatic showing of a known installation for bleaching and dyeing spooled threads.
FIG. 2 is a somewhat less diagrammatic showing of the kier in the installation as shown in FIG. 1.
FIG. 3 is a diagrammatic showing of an installation used for performing the method for bleaching and dyeing spooled threads according to the invention.
In the various figures, the same reference numerals pertain to similar elements.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The known installation as shown in FIG. 1 comprises a kier 1, an expansion tank 2 which is also used to add liquid, a tank 3 used for preparing the bleaching solution, pumps 5 and 6, a heat exchanger 11 and various pipes and valves which will be further described hereinafter.
The kier 1 shown less diagrammatically in FIG. 2, is fitted with a material-holder for spooled threads 69. Said spooled threads bound inside said kier a first space 67 on the inner side of said spooled threads 69 and a second space 68 on the outer side therefrom.
The first inner space 67 is essentially comprised of the center channels of the stacked spooled threads. The second outer outer space 68 is comprised of the complete volume surrounding said spooled threads 69. As may be seen in FIG. 2, there is nowhere a direct communication between said inner space 67 and outer space 68. Liquid can flow from inner space 67 to outer space 68 or vice versa but through the spooled threads 69.
A closed circuit is formed by said inner space 67, pipes 7 and 8, pump 5, pipes 9 and 10, inner space 68 and spooled threads 69.
Said pump 5 forces the liquid in the direction shown by arrow 70, thus in such a direction that through said spooled threads 69 the liquid flows from the inner space 67 towards the outer space 68.
The heat exchanger 11 is cut-in into pipe 9.
Said kier 1 is connected to the main discharge pipe 13 through said pipe 10 and by the discharge pipe 14 which comprises valve 15.
The suction side of pump 15 is connected not only to pipe 9 but also to pipe 29 which comprises the valve 30 and which is fed by pump 6 from expansion tank 2 through pipes 16 and 71.
A pipe 23 communicates with the top portion from outer space 68 of kier 1 and passes through said kier bottom without communicating with inner space 67. Said pipe 23 is connected by pipe 24 to pipe 25 which comprises valve 26 and opens in expansion tank 2.
The liquid from the top portion of outer space 68 can thus overflow through pipes 23, 24 and 25, when valve 26 is open, into expansion tank 2 from which the liquid is sucked by pump 6 and forced through pipe 29 when valve 30 is open, into that circuit formed by pump 5, pipes 8 and 7, kier 1 and pipes 10 and 9.
Said pipe 16 is also connected to the main discharge pipe 13 by pipe 17 which comprises valve 18.
Pipe 25 is also connected by pipe 27 comprising a safety valve 28, to the main discharge pipe 13. Said kier 1 can thus also overflow into said main discharge pipe 13 through pipes 23, 24 and 27.
The top portion of outer space 68 is further connected to the main discharge pipe 13 through connection 63 and a pipe 35 which comprises valve 36.
The preparation tank 3 is fed with water by pipe 37 which comprises valve 38. Said tank 3 is connected to the main discharge pipe 13 by pipe 19 comprising valve 20. Pipe 31 connects pipe 19 on the one hand to pipes 9 and 29 on the other hand. Said pipe 31 comprises a valve 32 and on the side of pipes 9 and 29 relative to said valve, a feed pipe 33 which comprises a valve 34.
The installation as shown in FIG. 1 and the kier as shown in FIG. 2 which have been described above are known. It is also known to connect pipe 7 to a steam source to feed steam into the inner space 67 and to connect pipe 10 to a steam source to feed steam into outer space 68.
The installation for performing the method according to the invention and shown diagrammatically in FIG. 3 has a plurality of additional components which will be described hereinafter.
A vacuum pump is connected by a pipe 39 comprising a valve 40, to the connector 63 provided in the top portion of kier 1. The same connector 63 is connected by a pipe 41 comprising a valve 42, to a pressurized air source.
The kier is further provided with a level regulator 48.
A steam feed source feeds pipe 43 which is connected by pipe 44, comprising valve 45, to pipe 23 opening inside the top portion of outer space 68 in kier 1.
It is to be noted that as opposed to the structure in the known installation described above, the steam is fed to the top portion of outer space 68 in the installation shown in FIG. 3.
The pipe 46 comprising valve 47, connects pipe 43 fed by the steam source to pipe 7 opening inside inner space 67 from kier 1.
The pipe 14 is connected between valve 15 and pipe 10 to a pipe 49 which opens inside the top portion of tank 3 used for preparing the bleaching solution.
The pipe 49 opens inside tank 3 in a point which lies above the maximum level of the liquid inside said tank. The pipe 49 comprises a temperature-measuring device 50. Said device 50 controls a valve 51 which is cut-in into pipe 49, to close said valve when the measured temperature rises above a pre-determined value. The temperature-measuring device 50 is arranged between valve 51 and preparation tank 3. Said valve 51 is thus closed but when said pre-determined temperature has already been reached upstream of said valve in the direction of tank 3.
Another temperature-measuring device 66 measures the temperature inside a spooled thread 69 and controls the starting of a timer when a pre-determined temperature is reached, said timer closing valve 45 and/or valve 47 after a pre-determined time interval.
A valve 12 is cut-in into that pipe 8 which connects pipe 7 to pump 5. Said valve 12 is normally open; all the other valves are normally closed.
A pipe 64 comprising valve 65, connects pipe 8 between pipe 7 and valve 12, to the main discharge pipe 13.
Pipes 52 and 54 for feeding products which are part of the bleaching or dyeing solution, open in tank 3 and comprise metering pumps 53 and 55. Pipe 52 is used for instance to add a bleaching agent, for example hydrogen peroxide to the bath which is prepared and reconditioned inside tank 3; the flow rate of said agent can be adjusted by metering pump 53 under the control of an automatic titrating device 72. Pipe 54 is used for instance to add an alkali to adjust or re-adjust the suitable pH for the bath. Said alkali flow-rate is adjusted by metering pump 55 according to the pH-value as measured by the pH-meter 73.
Tank 3 is further provided with a stirrer 56 and a level regulator 57.
The installation as shown in FIG. 3 allows working some new methods requiring a shorter time interval for bleaching or dyeing, and/or which are less costly, and/or which give a product with a better quality.
A method which may be worked in the installation as shown in FIG. 3 is a bleaching method which also makes use of a steam treatment. Said method essentially comprises an impregnating step, a recuperating step combined with exhausting air from the kier, and a steam treatment step, possibly followed by soaping and other finishing operations.
Said various treatments will be described hereinafter.
a. Impregnating with the bleaching solution
In tank 3 is prepared a bleaching solution at room temperature, which lies normally between 18° and 25° C.
Said solution preferably comprises a wetting agent having a limited dispersing action and an anti-foam action. The temperature in the range from 18° to 25° C. of the bleaching solution which is also retained when said solution lies in kier 1, is preferred due to higher temperatures causing possibly a heat-decomposition of the solution. The wetting agent has preferably a limited dispersing action as the dispersion increases the danger of migrating; the agent has preferably an anti-foam action to prevent the building-up of foam during the steam treatment preventing a fast heating of the spools.
Use is made for example of 0.3 cc wetting agent per liter of the solution and said agent is for instance on the basis of etherified sulfate from phosphoric acid with anti-foam action.
Said bleaching solution is fed to the kier 1 from tank 3 by opening valve 32 and starting pump 5. When a sufficient amount of the solution has been fed in this way to kier 1, the valve 32 is closed. It is possible to work with different levels inside the kier, but it is required to retain an air cushion above the liquid.
In a first variation, the liquid level inside kier 1 is such that the spooled threads are completely immersed. To provide such variation, the valve 26 is opened, pump 6 is operating, valve 30 is open and pump 5 causes flowing through pipes 10, 9, 8 and 7 in the direction of arrow 70. The static pressure inside the kier is obtained by means of pump 6.
As pump 5 causes flowing in the direction of arrow 70, the bleaching solution passes through the spooled threads 69 from inner space 67 towards outer space 68.
In a second variation, said spooled threads 69 are partly immersed in the bleaching solution or are not immersed at all.
In this second variation, the level of the bleaching solution inside the kier is determined by the level regulator 48. To work according to this variation, the valve 42 is opened to bring the pressure inside kier 1 to about 2 bars. Pump 5 is started to cause a flow through pipes 10, 9, 8 and 7 in the direction of arrow 70 to let the solution pass through spooled threads 69 from inner space 67 towards outer space 68. The duration of the impregnation is dependent in both cases on the pump characteristics, but lies generally in a range from 5 to 10 minutes.
In both variations, the bleaching solution can be on the basis of hydrogen peroxide or sodium chlorite.
In both cases by using the above-mentioned wetting agent with said proportion, there is obtained a liquid absorption by the cotton thread in the range from 140 to 160%.
It is to be noted that the solution amount which is absorbed by the cotton is not determined by a pressurized-air squeezing or by a vacuum suction, thus by operations which follow the impegnation proper, but actually by means of a suitable proportion of a suitable wetting agent in the impregnating bath. This way of regulating the liquid absorption proportion in the cotton has the advantage relative to the pressurized-air squeezing, that the air discharge before the steam treatment is made.
b. Recovery of the bleaching solution in combination with exhausting air from the kier
After the above-described impregnating, pump 5 is stopped and possibly pump 6 when same is still working, and valve 26 is closed when same is open. Valve 45 is opened and thus steam is fed to the top portion of outer space 68. It is to be noted that whatever the variation of impregnating being performed, there is always an air cushion above the liquid which is present inside the kier. The steam which is fed due to opening of valve 45 through pipe 23 into the top portion of kier 1, flows to the volume above said air cushion which forms a heat-isolating screen between the steam on the one hand and the bath on the other hand.
The valve 51 is opened. The bath is forced through pipes 10, 14 and 49 to tank 3. During such forcing-back operation, the air cushion acts as heat isolation and the bath is not markedly heated by the steam forcing same back. The temperature-measuring device 50 provided at the inlet to pipe 49 but beyond valve 51 in the direction of tank 3, controls said valve 51. Said device 50 is so adjusted that it closes the valve when the temperature it is subjected to rises above a determined value. Said value corresponds to the steam temperature. The discharge from the kier is thus stopped at the moment where the steam has reached the temperature-measuring device 50 and has thus flowed past valve 51.
The temperature-measuring device should be sensitive both to liquids and gases. The bleaching solution fed to tank 3 is conditioned back when required, by the addition of agents which are fed through pipes 52 and 54 by said metering pumps 53 and 55.
Indeed, the composition of said bleaching solution has changed during the treatment inside the kier. On the one hand, agents originally present in the solution have reacted with the spooled threads. On the other hand, elements from the thread and reaction products have entered the solution. Said solution has thus to be partly prepared again. It has been noticed in actual practice that it is possible to use for about ten times the same bleaching solution when after each treatment, bleaching agent and alkali are added to the solution when same has been forced back to tank 3. The bath composition and the forming-back thereof vary according to the thread to be treated. When the bleaching agent is hydrogen peroxide, the proportion thereof and the pH value as to be retained constant. The pH value can be ascertained with a pH-meter and the hydrogen peroxide proportion can be ascertained by titrating with potassium permanganate.
For Bresilian 20/2 cotton, the bath composition is for instance as follows:
25 cc/l 35% H 2 O 2
0.9 cc/l NaOH, 36° Be
3 g/l organic stabilizer
0.3 cc/l wetting agent
pH: 11
After each treatment when the liquid used for said treatment has been forced back to the preparation tank 3, the pH value is restored by adding caustic soda and the hydrogen peroxide proportion is restored by adding a suitable amount of peroxide as determined by titrating with potassium permanganate.
c. Stream treatment
After closing valve 51, that is when the liquid has been completely transferred from kier 1 to tank 3, valve 47 is also opened, valve 45 remaining open. Steam is thus fed at the top of outer space 68 through pipe 23 and at the bottom of inner space 67 through pipe 7. It is to be noted that as opposed to what occurs with the known methods, steam is simultaneously and not alternately fed to inner space 67 and outer space 68. Said steam thus heats spooled threads 69 on both sides, that is both from the inside and the outside. The steam is used substantially only to heat the spooled threads and said heating being made both from the inside and the outside results in the heating being fast and also distributed as uniformly as possible through the spooled threads. A temperature gradient through the spooled threads is thus prevented. Such a temperature gradient would enhance migrating.
There occurs some condensing inside the spooled threads, which increases the amount of absorbed liquid from about 150% to about 170%.
The heating duration should be as short as possible to prevent migrating. Said duration can be for instance of about 5 minutes. The steam temperature is for example in the range from 120° to 130° C. Use may for example be made of steam with a pressure of 1.4 bars which corresponds to a temperature of 122° C. The steam treatment goes on after the heating step.
The duration of such treatment is dependent on the nature of the cotton and the composition of the bleaching bath used previously, but it is for example about 15 minutes. The optimum duration is to be determined beforehand for every cotton to be treated and for every particular composition of the bleaching solution.
To obtain identical results from every treatment, it is required that the duration of the steam treatment be constant, said duration being determined from that moment where the spooled threads have reached the maximum temperature thereof. To obtain such a constant duration, there is provided the temperature-measuring device 66 inside one spooled thread 69 and said device 66 controls according to the measured temperature, said valves 45, 47 and 15.
The control should be such that the temperature-measuring device 66 when the pre-determined maximum temperature is reached inside the spooled thread, will start a timer which after a specific duration, for instance 12 minutes, will close valves 45 and 47 and open valve 15.
Spooled threads 69 are thus treated with steam during a fixed time interval, for instance about 12 minutes, from that moment where the spooled threads have been heated enough for the treatment temperature to have reached the middle area of the spooled thread.
The closing of valves 45 and 47 and opening of valve 15 results in a depressurizing of the kier. When no overpressure is present any more inside kier 1, valve 15 is closed and the following steps of the treatment are performed.
As shown in dotted lines in FIGS. 1 and 3, the cover of kier 1 may be connected directly to pipe 25. In such a case pipes 23 and 24 may be dispensed with in the embodiment as shown in FIG. 1 and pipe 23 may be dispensed with in the embodiment as shown in FIG. 3.
In this case the overflow from kier 1 occurs through pipe 24', either to expansion tank 2 when valve 26 is open, or to the main discharge pipe 13 when valve 26 is closed. As regards the overflow from kier 1, pipe 24' thus fulfills the function of pipes 23 and 24 in the embodiments as shown in FIGS. 1 and 3.
The pipe 24' also allows in the embodiment from FIG. 3, feeding steam to the top portion of outer space 68 when valve 45 is open. Indeed the steam may than flow through pipes 43, 44, 24, 25 and 24' to the top portion of said outer space 68. This does not change the above-described functions of the known installation shown in FIG. 1 and of the installation according to the invention shown in FIG. 3.
It must be understood that the invention is in no way limited to the above-described embodiments and that many changes can be brought therein without departing from the scope of the invention as defined by the appended claims.
|
The method comprises the steps of impregnating spooled threads with a cold treatment liquid inside a kier, leaving an air cushion above the liquid inside the kier, discharging the liquid from the kier through a liquid discharge outlet by feeding steam above the air cushion, stopping the discharge when the steam reaches the liquid discharge outlet, and treating the spooled threads with steam inside the kier.
| 3
|
PRIORITY CLAIMS
[0001] This application claims priority to U.S. Provisional Application No. 62/493,079, filed on Jun. 21, 2016, which is hereby incorporated by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention is generally directed to devices that permit the attachment of implements or tools to the bucket or front-end loader of a tractor or other mobile unit.
BACKGROUND ART OF THE INVENTION
[0003] Tractors and other mobile units (jointly referred to herein as “tractors”) with buckets, front-end loaders, or back-end loaders (all of which are jointly referred to herein as “buckets”) are used for handling and moving many types of particulate material. Such buckets are normally supported by one or more arms of the tractor, where the arms are hydraulically actuated up and down using a motor and the bucket is moved forward or backward with the movement of the tractor. The buckets are normally used to scrape or scoop up particulate material and move that material from one location to another. For instance, buckets attached to tractors are frequently used for scooping and moving earth, sand, gravel, rocks, snow,and many other types of particulate material.
[0004] While such buckets are well-suited for handling and moving particulate materials, they are less satisfactory for handling other types of materials and for performing other types of work that frequently becomes necessary in rural or construction settings. For instance, moving piles of brush, picking up pallets on which materials are stacked, moving rubbish and trash piles, hauling large hay bales, clearing vines or smoothing a road surface are tasks that are not easily accomplished by use of a standard tractor bucket. As a result, the need frequently arises to remove the bucket from the tractor and exchange it for a separate implement (the terms “implement” and “tool” are treated as interchangeable) that can be directly mounted to the arms of the tractor for use in performing a particular task or type of work. Making such a changeover from a bucket to a separate implement that is directly mounted onto a tractor is cumbersome, inefficient and requires the substantial expenditure of time and effort to remove the bucket and then remount the implement on the arms of the tractor. It is preferable to avoid this type of inefficiency, if possible.
[0005] Several attempts have been made in the past to provide for an implement adapter device that will permit the attachment of a separate implement to the bucket of a tractor. Such implement adapter devices have taken the form of a device that has a frontal portion located in the front of the bucket on which the workload or workpiece is supported during the handling process. These devices are supported by the leading edge of the bottom wall of a bucket where the main structure of the implement adapter device overlies the leading edge of the bottom wall of the bucket and the device has a slot or groove into which the leading edge of the bottom wall of the bucket is received. The working load supported by the front end portion of these implement adapter devices is typically counter-balanced by a rear portion that underlies and bears against the bottom wall of the bucket so that the support for the implement adapter device and the supported workload is designed on cantilever principles. In several instances these types of implement adapter devices use clamping means in which the leading edge of the bucket is maintained in the slot or groove of the device with removable clamping means that clamp the device onto one or more edges of the bucket. These types of clamping devices often loosen during use and permit the implement adapter device to separate from the walls of the bucket.
[0006] In other instances, mechanical fasteners that rigidly affix implements directly to one or more walls of a bucket or loader have been advocated. These methods require substantial time and effort to manually rigidly affix an implement to a bucket because they require mechanical interconnection of the implement directly with the bucket. Further, such methods require additional time and effort to mechanically disconnect the implement from the bucket when the implement is no longer in use and the user wishes to return to using the bucket by itself. Such changeovers waste time and effort during the initial rigid affixation of the implement directly to the bucket and during the subsequent mechanical removal of implement from the bucket.
[0007] Another method which has been suggested for securing implements to a bucket is to use chains, ropes, or similar flexible attachment means to fasten implements or implement adapters to one or more bucket walls. This approach may also entail the use of an overcenter arm, a buckle, pulley or similar device for adjusting the overall length of the fastener. However, it is often difficult to maintain a tight connection that prevents movement of the implement or implement adapter in this arrangement, which means that movement of the implements relative to the bucket is possible and therefore use of the implements becomes problematic.
[0008] In an effort to address the problems exhibited by the aforementioned types of implement adapter devices and methods, a number of somewhat more sophisticated implement adapter mechanisms have been proposed. For instance, U.S. Pat. No. 4,550,512 to Felstet discloses an implement adapter system involving a bucket with built-in sockets for receiving an implement, where the sockets are part of the side walls and bottom wall of the bucket itself Felstet's mechanism involves the insertion of part of an implement directly into the sockets that are disposed within the body of the bucket and then rigid affixation of the implement to the bucket using bolts that are inserted through the bucket's sockets and through the implement. Likewise, U.S. Pat. No. 6 , 088 , 938 to Logan discloses an implement adapter device comprised of a plate for attaching implements that is rigidly connected to an excavator by at least four arms. A pair of said aims are coupled with the wrist pin of the excavator,and a second pair of said arms are rigidly fastened to the inside portion of the side walls of the excavator. The patent to Logan also discloses a hinged attachment device for connecting tools or implements to an excavator. The attachment device is connected to a plate with multiple hinges that engage the excavator. The attachment device pivots about the hinges and pins are used to secure the base of the attachment to the excavator.
[0009] U.S. Pat. No. 6,848,142 to Truan discloses a bucket-mounted sweeper implement and a proposed apparatus for attaching such an implement to a bucket. The Truan Patent discloses an implement that is permanently, rigidly affixed to a housing wherein the housing has a pair of top mounting brackets on both sides of the housing that are each provided with multiple attachment points. When it is desired to place the implement into use, the implement and its housing and mounting brackets may be bolted to two mounting arms that are themselves pinned to the inside portions of the side walls of a bucket. The apparatus appears to be primarily designed for use with a brush-type implement with a housing that can be connected on each of its ends to the mounting arms at the location of the mounting brackets and will then hang down from the bucket and can be moved along a surface for sweeping particulate materials. The apparatus is problematic during actual use because removal of a specific implement requites that the implement and its mounting brackets must be unbolted from each of the mounting arms. Alternatively, an implement can be removed by unpinning the mounting arms from the sidewalls of the bucket while the implement is still bolted to the mounting arms, but this does not allow for immediate attachment of a different implement to the bucket because such a changeover to another implement would still require the unbolting of the implement from the mounting arms. Thus, a changeover between implements is cumbersome and inefficient. It is also unclear how much support is provided to various implements by the feet of the mounting arms that engage with the bottom wall of the bucket, and it is possible that heavier implements may not be well supported by the apparatus, whereas the brush implement disclosed by Truan apparently receives at least some physical support from the ground or surface underlying the brush implement's bristles.
SUMMARY
[0010] An implement attachment device for the attachment of various implements to a tractor bucket is disclosed. Problems and limitations in the prior art are overcome by the disclosed implement attachment device that permits rapid attachment or detachment of implements to a tractor bucket using one or more receivers that are provided by a main receiver bar. The implements are removably pinned in place to the main receiver bar by pins that pass through holes provided in the shank of the implements and through holes provided in the receivers of the main receiver bar. Additionally, the implement attachment device may be pivoted and reversibly locked into either an upright, stowed position for standard use of the tractor bucket, or may be pivoted and locked into a lower, use-ready position for the use of one or more attached. implements that are connected to the main receiver bar.
[0011] The implement attachment device includes a main receiver bar that is connected to two swing arms. The two swing arms are each connected to a sidewall of the tractor bucket with both a pivot pin and a positioning pin. The positioning pin may be inserted in either a top position hole when the implement attachment device is in the upright, stowed position, or in a bottom position hole when the implement attachment device is in the lower, use-ready position. In order to switch from the stowed position to the use-ready position, the positioning pin is removed from the top position hole, the swing arms and attached main receiver bar are rotated downward away from the top edge of the bucket and toward the bottom edge of the bucket, and then the swing arms are each re-pinned using the positioning pins by inserting the positioning pins through the bottom position holes. This process will move the implement attachment device to the lower, use-ready position. It should be appreciated that this process may be reversed in order to move the implement attachment device, and any attached implements attached thereto, back to the stowed position near the top of the tractor bucket.
[0012] The implement attachment device is also adjustable in relation to the width of the tractor bucket to which it is intended to be attached and used. At the location of the connections between the two swing arms and the main receiver bar, the swing arms are of a smaller diameter and will slidably fit into open ends of the main receiver bar and may be slid to and fro within the body of the main receiver bar until the time of final assembly, at which point the two swing arms are rigidly affixed to the main receiver bar using rigid affixation means. Thus, the implement attachment device can be adjusted to fit the width of most tractor buckets during assembly of the device onto the tractor bucket.
[0013] The implement attachment device hereby disclosed overcomes a number of limitations with the prior art because it allows for rapid changeover between different types of implements and because it also allows for implements to remain attached to the bucket of a tractor yet they can be moved into a stowed position in which the tractor's bucket may be used in standard fashion for an interim time between consecutive uses of the attached implements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The disclosed implement attachment device will be described with reference to the accompanying drawings, which show important sample embodiments, wherein:
[0015] FIG. 1 is a front perspective view of the implement attachment device and implements mounted on a tractor bucket;
[0016] FIG. 2 is an exploded perspective view of the implement attachment device, attached implements, and a tractor bucket;
[0017] FIG. 3 is a closer perspective view of the swing arm and a portion of the main receiver bar of the implement attachment device demonstrating how the swing arm and the main receiver bar are slidably connected during assembly of the device;
[0018] FIG. 4 is a front view of the implement attachment device mounted on the bucket of a tractor demonstrating how the positioning pins may be removed from the bottom position holes in the tractor bucket's sidewalls;
[0019] FIG. 5 is a front perspective view of the implement attachment device mounted on a tractor bucket demonstrating movement of the device from a use-ready position to a stowed position;
[0020] FIG. 6 is a side view of the implement attachment device mounted on a tractor bucket;
[0021] FIG. 7 is a side view of the implement attachment device mounted on a tractor bucket demonstrating scooping motion of the tractor bucket when the device is in a stowed position;
[0022] FIG. 8 is a front perspective view demonstrating movement of the tractor bucket when the device is in a stowed position;
[0023] FIG. 9 is a front perspective view of the implement attachment device mounted on a tractor bucket with the device in a use-ready position and with a platform type of implement connected to the tractor bucket using the device;
[0024] FIG. 10 is a front perspective view of the implement attachment device with a ball hitch implement attached to the tractor bucket using the device;
[0025] FIG. 11 is a side view of the tractor implement device mounted on the tractor bucket of a tractor with a roller implement connected to the bucket using the device and wherein the roller implement is being used to smooth a surface;
[0026] FIG. 12 is a front perspective view of the implement attachment device and a roller implement showing how the roller implement may be mounted onto the main receiver bar of the device in order to connect the roller implement to a tractor bucket.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] FIG. 1 illustrates an implement attachment device 7 configured to be mountable on a tractor bucket 3 where the tractor bucket is attached to one or more tractor arms 2 of a tractor 1 . The implement attachment device 7 includes a main receiver bar 10 that is provided with one or more receivers 12 that serve as sockets into which the shank 41 of an implement 40 may be fitted. An implement pin 16 is used to reversibly attach the implement 40 to the main receiver bar 10 by reversibly pinning the shank 41 of the implement 40 within the body of the receiver 12 . The main receiver bar 1 . 0 is rigidly affixed to a pair of swing arms 14 . In one embodiment, rigid affixation of the swing arms 14 to the main receiver bar 10 is accomplished by means of at least one fastener 18 per swing arm 14 rigidly affixing the swing arms 14 to the main receiver bar 10 . Each swing arm 14 is attached to a side wall 4 of the tractor bucket 3 by a pivot pin 20 and a positioning pin 22 . The implement attachment device 7 is shown in a use-ready position in FIG. 1 . in which the swing aims 14 are angled downward from the location of the pivot pin 20 toward the bottom wall 5 of the tractor bucket 3 such that the main receiver bar 10 is located toward the bottom of the bucket 3 and in close proximity to the front edge of the bottom wall 5 of the tractor bucket 3 with the one or more receivers 12 facing forward. As can be seen in referring to FIG. 1 , when the implement attachment device 7 is in a use-ready position, the top position hole 27 through each sidewall 4 of the bucket 3 is not in use because the positioning pin 22 is engaged in the bottom position hole (not shown) in order to maintain the implement attachment device 7 in the use-ready position. In a preferred embodiment, the implement attachment device 7 will also feature a pair of support members 24 , each of which is a protrusion that is rigidly affixed to, and extending from, a surface of each sidewall 4 of the tractor bucket 3 . The support members 24 physically support the swing arms 14 when the implement attachment device 7 is in the use-ready position as shown in FIG. 1 . The support members 24 are either a metal protrusion welded onto each sidewall 4 of the bucket 3 , or preferably, a bolt or screw that is rigidly affixed to the sidewall 4 , possibly using a nut or washer and nut where the bolt or screw is inserted through a support hole (not shown in FIG. 1 ) in the sidewall 4 and engages the nut on the opposing planar side of the sidewall 4 . It is also possible to use a pin as a rigid support member 24 without departing from the scope of the inventive concepts hereby disclosed. While the inventive concepts disclosed may be practiced without the rigid support members 24 , it is not advisable to do so since the support members 24 provide physical support for carrying heavier loads using the attached implements 40 .
[0028] FIG. 2 is an exploded front perspective view of the implement attachment device 7 and the tractor bucket 3 that illustrates additional features of the implement attachment device 7 . As can be seen in FIG. 2 , the main receiver bar 10 includes at least one, and preferably a multiplicity of, receivers 12 , wherein each receiver 12 has one or more receiver holes 17 that pass through one or more walls of the receiver 12 . As shown by path lines in FIG. 2 , an implement 40 may be inserted into a receiver 12 by inserting the shank 41 of the implement 40 into a receiver 12 and then inserting an implement pin 16 through the receiver holes 17 and through a pin hole 42 that is provided through the shank 41 of the implement 40 . The implement pin 16 may be any suitable type of attachment means such as a screw, bolt, hitch pin, or other similar attachment means, but in a preferred embodiment the implement pin 16 is a bolt or a pin secured in place by a cotter pin 11 (such as a clevis pin—cotter pin combination or other similar arrangement) that fits around an end of the implement pin 16 or through a hole provided through the implement pin 16 (not shown) to secure it in place in a manner that is well understood by those skilled in the art.
[0029] As can be appreciated from viewing the path lines shown in FIG. 2 , during assembly of the implement attachment device 7 onto the tractor bucket 3 , the pair of swing arms 14 will connect the main receiver bar 10 to the tractor bucket 3 . Each swing arm 14 has a top pivot end 15 and a bottom slide end 17 that are orthogonal to each other. The top pivot end 15 of each swing arm 14 is reversibly attached to a sidewall 4 of the tractor bucket 3 by means of a pivot pin 20 and a positioning pin 22 . As illustrated by path lines in FIG. 2 , when the implement attachment device 7 is assembled on the tractor bucket 3 , the pivot pin 20 is inserted through an arm pivot hole 30 that is disposed within the top pivot end 15 of each swing arm 14 , and also through a bucket pivot hole 21 that is disposed within each side wall 4 of the tractor bucket 3 . As further illustrated by path lines shown in FIG. 2 , the top pivot end 15 of each swing aim 14 is reversibly connected to the tractor bucket 3 with a positioning pin 22 that is reversibly inserted through an arm positioning hole 29 and into either a bottom position hole 23 or a top position hole 27 , both of which position holes are disposed at different locations within each sidewall 4 of the tractor bucket 3 .
[0030] After assembly, the implement attachment device 7 will be in a use-ready position when the positioning pin 22 is inserted through the arm positioning hole 29 and through the bottom position hole 23 . This arrangement will place the main receiver bar 10 into close proximity with the leading edge of the bottom wall 5 of the tractor bucket 3 with the one or more receivers 12 facing forward in relation to the bucket 3 , and in this use-ready position, any attached implement 40 held by the main receiver bar 10 will extend forward from the leading edge of the bottom wall 5 of the tractor bucket 3 . The implement attachment device 7 can be moved to a stowed position by removing the positioning pin 22 from the bottom position hole 23 , swinging the top pivot ends 15 of both swing arms 14 upwards such that the main body of the device, including both swing arms 14 and the main receiver bar 10 that is connected between then, is rotated upwards around the pivot pin 20 , and then inserting the positioning pin 22 into the top position hole 27 . These steps will move the implement attachment device 7 from a use-ready position to a stowed position in which the swing arms 14 and main receiver bar 10 are held in place near the top of the bucket 3 by the positioning pins 20 . Once the implement attachment device 7 , including each swing arm 14 and the main receiver bar 10 , is in the stowed position near the top of the tractor bucket 3 , the tractor bucket 3 can then be used to scoop up, handle, and move particulate material in standard manner without interference from the implement attachment device 7 or any implement 40 that may still be attached to the main receiver bar 10 of the device. The pivot pins 20 will stay in their position in which they are engaged through the arm pivot holes 30 of the swing arms 14 and through the bucket pivot holes 21 of each sidewall 4 during the entire time that the device is switched between a use-ready position and a stowed position.
[0031] As illustrated in FIG. 2 and FIG. 3 , during assembly of the implement attachment device 7 onto the tractor bucket 3 , the bottom slide ends 17 of the swing arms 14 are initially slidably connected to opposite ends of the main receiver bar 10 by inserting the bottom slide ends 17 in male-female fashion into openings that are disposed within each end of the main receiver bar 10 for receiving and slidably holding the bottom slide end 17 of a swing arm 14 . Each bottom slide end 17 has a smaller cross-sectional area or smaller diameter than the openings at the ends of the main receiver bar 10 that serve as receiving means for the bottom slide ends 17 , and therefore, during assembly but prior to final assembly, each bottom slide end 17 of each swing arm 14 is capable of sliding freely into and sliding to and fro within the body of the main receiver bar 10 . During the assembly process, each bottom slide end 17 is adjusted by sliding it within the body of the main receiver bar 10 to a point where each swing arm 14 is in position adjacent to a sidewall 4 of the bucket 3 such that the top pivot end 15 of each swing arras 14 can be pinned to a sidewall 4 of the tractor bucket 3 . The top pivot ends 15 of the swing arms 14 are then pinned to the bucket 3 using the pivot pins 20 that are inserted through the aim pivot holes 30 disposed within the pivot ends 15 and the bucket pivot holes 21 that are disposed within the sidewalls 4 , and optionally also using the positioning pins 22 to pin the pivot ends 15 of the swing arms 14 to the sidewalls 4 . Final assembly will involve the bottom slide ends 17 of each swing arm 14 being rigidly affixed to the main receiver bar 10 . In some embodiments, rigid affixation of the bottom slide end 17 of each swing arm 14 to the main receiver bar 10 may be accomplished using one or more pre-marked holes 32 in the bottom slide ends 17 and one or more pre-set holes 19 in the main receiver bar 10 , along with a bolt 18 . Rigid affixation of each bottom slide end 17 of each swing aim 14 to the main receiver bar 10 may alternatively be accomplished using any other rigid affixation means, including but not limited to use of a screw with a nut or nut and washer, welding, pinning, or any other similar means that are well understood in the art. To the extent that pre-marked holes 32 may optionally be located on the bottom slide end 17 of each swing arm 14 in some embodiments, along with pre-set holes 19 that may optionally be located on the main receiver bar 10 at predetermined distances apart, the locations and distances of such pre-marked holes 32 and pre-set holes 19 will be such that the overall structure of the implement attachment device 7 may be adjusted to fit tractor buckets of several different commonly-encountered widths at the time of assembly. Use of pre-marked holes 32 and pre-set holes 19 is not required to practice the invention, but are part of an optional embodiment. In a preferred embodiment, the implement attachment device 7 will be able to be assembled onto any tractor bucket 3 having a width of between 48 inches to 72 inches, with the width of the bucket 3 being the distance measured between the outside planar surfaces of the opposing sidewalls 4 of the bucket 3 . Thus, in such a preferred embodiment, the bottom slide ends 17 of the swing arms 14 are capable of being slidably adjusted during assembly by sliding them to and fro within the body of the main receiver bar 10 and then rigidly affixing each to the main receiver bar 10 during final assembly in a position such that the top pivot ends 15 of the pair of swing arms 14 will be anywhere from 48 inches to 72 inches apart when the implement attachment device 7 is finally assembled on a bucket, with the distance between the top pivot ends 15 of the swing arms 14 being determined by the width of the tractor bucket 3 onto which the device is being assembled.
[0032] FIG. 4 is a front view of the implement attachment device 7 mounted on a tractor bucket 3 , which is, in turn, mounted on tractor arms 2 of a tractor 1 . Arrows in FIG. 4 demonstrate the removal of the positioning pins 22 from the bottom position holes (not shown in front view) that are disposed through the sidewalls 4 of the tractor bucket 3 . Removal of the positioning pins 22 is required in order to switch the implement attachment device 7 from the use-ready position at the bottom of the tractor bucket 3 where the main receiver bar is located near the bottom wall 5 of the bucket 3 to a stowed position near the top of the tractor bucket 3 by rotating the main body of the device, including the swing arms 14 and the main receiver bar 10 , upwards around the pivot pins 20 that will stay in place during this switch.
[0033] FIG. 5 is a front perspective view of the implement attachment device 7 mounted on a tractor bucket 3 where the switching of the implement attachment device 7 from the use-ready position 101 that is shown in phantom with a dashed line, to an upright stowed position 102 , is illustrated. The curved arrow 103 illustrates rotation of the implement attachment device 7 and an attached implement 40 upward around the pivot pin 20 to the stowed position 102 . Additional arrows demonstrate insertion of the positioning pins 22 into the top position holes (not labeled) in order to place the device into the stowed position 102 near the top of the bucket 3 .
[0034] FIG. 6 is a side view of the implement attachment device 7 mounted on a tractor bucket 3 in the stowed position 102 . As can be observed in reference to FIG. 6 , when the device is in a stowed position 102 , both swing arms 14 , the main receiver bar (not visible in side view), and any implement 40 that may be attached to a receiver 12 by means of an implement pin 16 , will be located near the top of the bucket 3 and away from the bottom wall 5 of the bucket 3 . FIG. 6 illustrates that the positioning pins 22 are not engaged in the bottom position holes 23 that are disposed through each sidewall 4 , but rather, they are engaged with the top position holes (not shown) closer to the top of the bucket 3 such that the implement attachment device 7 is no longer in front of the tractor bucket 3 , but is in the stowed position 102 at the top of the bucket 3 .
[0035] FIG. 7 is a side view of the implement attachment device 7 illustrating use of the tractor bucket 3 to scoop materials up when the implement attachment device 7 is pinned in a stowed position 102 near the top of the bucket 3 . The tractor bucket 3 is illustrated as moving with scooping action from a first bucket location 202 ′ that is shown in phantom with dashed lines, to a second bucket location 202 , while the implement attachment device 7 remains in the stowed position 102 (the device in the stowed position prior to movement of the bucket is shown in phantom at location 102 ′ with dashed lines). As can be visualized and understood from reviewing FIG. 7 , when the implement attachment device 7 is pinned in a stowed position 102 , the implement attachment device 7 will be located away from the bottom wall 5 of the bucket 3 and therefore the bucket 3 can be used in standard fashion to scoop up particulate materials and move them from one place to another.
[0036] FIG. 8 is a front perspective view of the implement attachment device 7 assembled on a tractor bucket 3 where the tractor bucket 3 is illustrated as being raised upward by a curved arrow 303 in order to move or haul particulate materials in the bucket 3 in standard fashion. As can be seen, when the tractor bucket 3 is raised from an initial lower position 301 illustrated in phantom by dashed lines, to a subsequent higher position 302 , the implement attachment device 7 , including the main receiver bar 10 and the swing anus 14 , along with any attached implement 40 , moves with the bucket 3 as it is raised to the higher position 302 . Thus, the implement attachment device 7 can remain in the stowed position without interfering with an operator raising or lowering the tractor bucket 3 , and without interfering with moving or hauling of particulate materials from one place to another using the tractor 1 and its bucket 3 .
[0037] FIG. 9 is a front perspective view of the implement attachment device 7 as assembled on a tractor bucket 3 with the implement attachment device 7 in a use-ready position in which the positioning pins 22 have been removed from the top position holes 27 that are disposed within the sidewalls 4 of the tractor bucket 3 and have been re-pinned in the bottom position holes (not labeled) that are located closer to the bottom wall 5 of the tractor bucket 3 . The embodiment of the implement attachment device 7 is shown with the optional support members 24 in place on the sidewalls 4 to provide physical support for the swing arms 14 of the device. FIG. 9 illustrates the fact that a platform type implement 50 may be attached to the bucket 3 using the implement attachment device 7 by inserting the shanks (not shown) of the platform type implement 50 into the receivers 12 of the main receiver bar and reversibly pinning them in place by inserting implement pins (not labeled) through one or more receiver holes (not labeled) disposed within the receivers 12 and through pin holes disposed (not visualized) within the shanks of the platform type implement 50 in a similar fashion to what was previously illustrated for the implement 40 that is shown in FIG. 2 .
[0038] FIG. 10 demonstrates that a ball hitch type implement 60 may be inserted into a receiver 12 of the main receiver bar 10 and pinned in place using an implement pin 16 . The ball hitch type implement 60 allows the operator of a tractor to move ball hitch trailers (not shown) from one place to another using a tractor on which the device has been assembled.
[0039] FIG. 11 and FIG. 12 both illustrate that a roller implement 72 may be attached using the device by the interconnection method 70 demonstrated in which implement pins 16 are used to connect the roller implement 72 . FIG. 12 also specifically illustrates an alternative embodiment of the implement attachment device 74 in which the entire implement attachment device is all one unitary piece of metal or plastic and there is no assembly of individual swing arms and main receiver bar to form an assembly because the entire implement attachment bar is a single, unitary piece of equipment that comprises a metal or plastic frame with main receiver bar and swing arms that are all part of the unitary structure that can be attached to the sidewalls of a tractor bucket and used to attach various types of implements such as the roller implement 72 that is illustrated.
[0040] The primary purpose of FIG. 10 - FIG. 12 is to demonstrate that a multiplicity of different types of tools and implements may be attached to a tractor bucket using the implement attachment device and that the types of tools or implements that may be attached using the device are not limited to fork or tine type tools. In practice, several other implements that are not illustrated by the drawings, such as a grape vine puller and an elongated hay spike, have also been demonstrated as implements that may be attached to a tractor bucket using the implement attachment device, wherein each implement has one or more shanks with pin holes such that the shanks of the implements may be inserted into one or more receivers of the main receiver bar and pinned in place with implement pins in a manner similar to what has been shown and illustrated in the attached patent drawings.
[0041] For purposes of the drawings and the description provided hereinabove, the connections between the swing arms 14 and the sidewalls 4 of the bucket 3 may be pins, bolts, screws, or any other similar fastener that may be used to reversibly connect the swing arms 14 to the sidewalls 4 utilizing the various types of holes in the swing arms 14 and sidewalls as have been described. The terms “pin,” “bolt,” or screw,” are not meant to be limiting, and it should be understood that any type of reversible fastener that allows for rotational pivoting motion of the top pivot end 15 of the swing arms 14 in order to move the implement attachment device 7 between the use-ready position 101 and the stowed position 102 comes within the scope of the inventive concepts defined within the appended hereto. Likewise, any type of reversible fastener that allows for reversibly locking the implement attachment device 7 in place in either the stowed position 102 or the use-ready position 101 comes within the scope of the inventive concepts.
[0042] In a preferred embodiment of the inventive concepts disclosed, all of the connections between the pivot ends 15 of the swing arms 14 and the sidewalls 4 of the bucket 3 are pins that may be relatively quickly pinned or unpinned in place as described in the foregoing descriptions. The reason for the use of pins in the preferred embodiment instead of bolts or screws with a nut or locking nut, is that pins can be readily removed in order to disconnect the entire implement attachment device from the bucket of a tractor and then simply move the tractor and its bucket backward away from the device. While other previous implement adapter devices have been touted as providing a “quick-release” feature or other similar ease of connection and disconnection, the implement attachment device that is hereby disclosed actually fulfills such promises because removal of two pins on each side of the tractor bucket is all that is required to disconnect the device from the tractor.
[0043] To the extent that pins are used in some embodiments of the device, including the preferred embodiment, the pins that are employed may be a clevis pin—cotter pin type combination, bow-tie locking cotter pin combination, hitch pin, or any other similar type of pin or pin combination that provides for easy connection and easy disconnection of the swing anus and the sidewalls of the bucket. The connections may also be accomplished using bolts, screws, washers, or other similar reversible connection means, but quickly removable pins are the preferred types of connectors for the device for the reasons stated above.
[0044] It should also be recognized that the support members 24 shown in the drawings and discussed in the description above, though optional, are an important aspect of the preferred embodiment of the inventive concepts hereby disclosed. While such support members 24 connected to the sidewalls are not strictly required to practice the inventive concepts disclosed, to the extent that extremely heavy loads are to be loaded onto one or more implements attached to the tractor bucket 2 using the implement attachment device 7 , the support members 24 will provide a significant amount of physical support to the swing arms 14 supporting the heavy load. The support members 24 may be welded metal protrusions, bolts, screws, washers, or any other type of solid protrusion from the sidewalls 4 that serves as a support for the swing arms 14 . Alternatively, the inventive concepts disclosed may be practiced with alternative types of support for the device, such as support means rigidly affixed to the bottom wall 5 of the bucket 3 that would underlie and support the main receiver bar 10 when it is in a use-ready position. Although such alternative means of support come within the scope of the inventive disclosure described and hereinafter claimed, the inventor's preferred embodiment involves support members that are rigid protrusions from the sidewalls of the bucket.
[0045] With regard to the pre-marked holes 32 provided along the bottom slide end 17 of each swing arm 14 and the pre-set holes 19 provided in the main receiver bar 10 in some embodiments, it should be appreciated that such pre-marked holes 32 and such pre-set holes 19 are not strictly necessary to practice the inventive concepts disclosed. Furthermore, to the extent that such pre-marked holes 32 and such pre-set holes 19 are used in a preferred embodiment of the implement attachment device 7 , there will be two pre-set holes 19 , with each of pre-set holes 19 being a true hole through the main receiver bar 10 that is located in relative proximity to the ends of the main receiver bar 10 and at some distance from the center of the main receiver bar 10 . With reference to the pre-marked holes 32 , such pre-marked holes 32 will not be true holes through the bottom slide ends 17 of the swing arms 14 , but rather, the pre-marked holes 32 will be a multiplicity of dimples or etched spots within each of the bottom slide ends 17 where a true hole through each of the bottom slide ends 17 can be drilled during assembly of the device in order to subsequently rigidly affix the bottom slide ends 17 of the swing arms 14 to the main receiver bar 10 by means of bolts, screws, or pins in the manner described above. The reason for using dimples or etched spots for the pre-marked holes 32 along the bottom slide ends 17 rather than actual pre-drilled holes is that the inventor has discovered during a reduction to practice that a multiplicity of pre-drilled holes that are actual holes through bottom slide ends 17 of the swing arms 14 reduces the overall integrity and physical strength of the entire implement attachment device 7 once it is assembled and put into use. As a result, in a preferred embodiment incorporating,the pre-marked holes 32 that are set at certain distances along the bottom slide ends 17 , the assembler of the device will position the bottom slide ends 17 of the swing arms 14 within the ends of the main receiver bar 10 and slide the swing arms 14 to the proper width apart in relation to the width of the tractor bucket 3 , and then the assembler will drill an actual hole through one of the pre-marked holes 32 in each of the bottom slide ends 17 and use a bolt, screw, or pin to rigidly affix each of the swing arms 14 to the main receiver bar 10 using each of the now-drilled pre-marked holes 32 in a manner that is well understood in the art.
[0046] Although the inventive concepts hereby disclosed have been described with reference to specific embodiments, it should be understood that the above-described specific embodiments are not intended to limit the scope of the inventive concepts disclosed, but merely to illustrate some of the specific embodiments of the implement attachment device. It should be understood that various modifications of the disclosed embodiments, as well as alternative embodiments of the inventive concepts, will be apparent to persons skilled in the art upon reference to the description of the embodiments that is provided or upon reference to the appended claims. It is, therefore, contemplated that the appended claims will cover and read upon all such modifications and alternative embodiments that fall within the scope of the inventive concepts that are claimed by the inventor.
|
An implement attachment device for tractors allowing for easy and quick attachment of implements and tools to a tractor bucket along with correspondingly easy and quick detachment of such implements and tools, wherein such device may itself may be readily connected or disconnected to the bucket and while connected may be easily switched from a bottom use-ready position to a top stowed position in relation to the tractor bucket.
| 4
|
FIELD OF THE INVENTION
The present invention relates to an 18 F-labeled azide compound, a reagent for 18 F-labeling, and a method for 18 F-labeling of an alkyne compound using the same. The present invention is suitably applicable to production of a radioactive tracer indispensable for positron emission tomography (hereinafter, called “PET”).
BACKGROUND OF THE INVENTION
PET is a method that includes administering, into a living body, a tracer labeled with a short-term radionuclide which releases positrons such as 18 F or 11 C so that γ rays generated from the tracer is measured by a PET camera (detector comprising a gamma ray scintillator and a photoelectron multiplier tube), and imaging a body distribution of the γ ray by a computer. The PET can non-invasively and quantitatively track down the movement of materials over time in vivo, therefore, is now actively employed as a very useful measurement technique in many different fields such as biology, development of pharmaceutical products, and medical services.
Examples of the short-term radionuclide used in the PET are 18 F and 11 C, and compounds labeled with these radionuclides are used as the tracer. There is a very broad application range for the 11 C utilizing carbon atoms present in organic compounds, therefore, 11 C can be considered to be an ideal radionuclide. However, the 11 C has such a short half life as 20 minutes, imposing the restriction that the process from synthesis through PET measurement must be completed within a very short time frame. In contrast, the 18 F having a half life longer than that of the 11 C, 110 minutes, is easy to handle and widely used in, for example, 18 F-labeled glucose. Despite such an advantageous half life, positrons released by the 18 F decrease with time, making the PET measurement similarly difficult. Faced with such a difficulty, a fast and simplified 18 F labeling method is desirably accomplished.
To prepare an 18 F-labeled compound, its base material, 18 F, is supplied through nuclide transformation by a cyclotron. More specifically, ions accelerated by the cyclotron are crashed into water including 18 O to invite nuclide transformation from 18 O to 18 F. The 18 F-labeled compound can be theoretically obtained when a very weak water solution including 18 F ions thus obtained and a compound selected as a PET target are reacted with each other.
In fact, it is conventionally extremely difficult to directly bond 18 F to the compound for the PET. Therefore, an indirect 18 F labeling method is employed, wherein an intermediate compound labeled with 18 F and having a functional group to be bonded to another compound (intermediate medium thus characterized is hereinafter called “ 18 F prosthetic group”) is prepared in advance and then bonded to the compound for the PET.
Examples of properties required for the 18 F prosthetic group are: 1) easily and speedily synthesizable; 2) bondable to a target compound rapidly and efficiently under temperate conditions; and 3) hardly affecting in-vivo kinetics of the target compound. To meet these requirements, an 18 F prosthetic group which leverages the Huisgen reaction is currently attracting attention.
Describing the Huisgen reaction, an organic azide compound and alkynes, as a result of a [3+2] cycloaddition reaction generated therebetween, are transformed into a 1,2,3-triasole derivative (see the following chemical formula).
In the case where a terminal alkyne is used as the alkynes, copper (I) ions work as a catalyst, and a 1,4-disubstituted body is selectively obtained. This reaction is not disturbed by any other functional groups, if present, such as alcohol, amine, amide, ester, and halide, therefore, a target material, triaosle, can be obtained at a high yield. The reaction uneventfully advances in any of reaction solvents such as alcohol, conventional organic solvents, and water. The asides and alkynes have a number of advantages; they can be easily introduced in various organic compounds, and they do not produce excessive post-reaction waste matters. Therefore, the asides and alkynes are cited as typical examples which represent the Click Chemistry advocated by K. B. Sharpless et al. who was awarded with Nobel Prize in Chemistry.
In the studies conducted in recent years using the Huisgen reaction, azide compounds or alkyne compounds labeled with 18 F are used as the 18 F prosthetic group to introduce the 18 F prosthetic group in any target compounds. Below are given specific examples of such studies.
Marik and Sutcliffe, University of California, Davis, fluorinated a tosylate body having an acetylene group on its molecular end in the presence of [ 18 F]KF and kalium scavenger (Kryptofi x222) and purified through distillation so that 18 F-labeled fluoroalkynes are obtained as the 18 F prosthetic group (Non-Patent Document 1). Then, they generated the Huisgen reaction between the 18 F prosthetic group and azidated peptide in the presence of a catalytic system including iodinated copper (I), sodium ascorbate, and di-isopropyl ethylamine as amine base to perform 18 F-labeling of the peptide at room temperature for 10 minutes (see the following reaction formula).
They further performed 18 F-labeling of α v β 6 specific peptide using the 18 F prosthetic group in which n=3 in the above formula, and successfully obtained PET images in mice in vivo (Non-Patent Document 2).
Another study using the 18 F prosthetic group in which n=1 in the above formula was also reported by a study group of Sungkyunkwan University, Korea (Non-Patent Document 3).
A study group representing SIEMENS MEDICAL SOLUTIONS USA, INC. reported the use of a compound comparable to n=0 in the above formula (Patent Document 1), wherein propargyl tosylate is 18 F-transformed to generate an 18 F prosthetic group ([ 18 F]-3-fluoropropyne) in a reaction container and leave the generated 18 F prosthetic group unpurified, and an overly large quantity of azide substrate is added to a reaction solution to generate a coupling reaction using copper (I) acetate.
The Non-Patent Document 4 recites an example in which an 18 F-labeled azide compound is used, wherein the Huisgen reaction is generated with oligopeptide having a terminal acetylene group by using [ 18 F] fluoroethylene azide as 18 F so that the oligopeptide is successfully labeled with 18 F (see the following chemical formula).
A study group of Inha University, Korea reported the use of a plurality of 18 F-labeled alkyne compounds and 18 F-labeled azide compounds (see the following chemical formula) as the 18 F prosthetic group, wherein they performed 18 F-labeling of a variety of substrates (see the Non-Patent Document 5). However, their method directly performing the coupling reaction without purifying the 18 F prosthetic group similarly uses an overly large quantity of compounds to be 18 F-labeled as the 18 F prosthetic group.
A study group of Stanford University purified the 18 F prosthetic group by employing preparative HPLC more easily automatable than distillation to thereby obtain an 18 F-labeled alkyne compound having a high purity (Non-Patent Document 6). They generated the Huisgen reaction using a catalytic system including copper sulfate—sodium ascorbate but no amine base to label ligands of integrin α v β 3 with 18 F and captured PET images in mice.
A study group of Dresden-Rossendor Research Center, Germany purified 4-[ 18 F]Fluoro-N-(prop-2-ynyl)benzamide synthesized by the following method by employing SPE (solid phase extraction) and used the purified material as the 18 F prosthetic group, and then performed the 18 F-labeling of azidated Neurotensin (8-13) peptide through the Huisgen reaction (Non-Patent Document 7).
They discussed the conditions of the Huisgen reaction to reduce the quantity of peptide used in each 18 F-labeling test, and found out that an optimal condition is to use the catalytic system including copper sulfate and sodium ascorbate with a borate buffer, and finally succeeded in reducing the quantity of azidated Neurotensin (8-13) peptide to 1 mg (approximately 1 μmol). However, it is necessary to further reduce the quantity for practical use.
A study group of TRIUMF, Canada, based on their hypothesis that aryl fluorine is probably more metabolically stable than aliphatic fluorine, developed an aryl fluorine 18 F prosthetic group synthesizable in one stage, which was reported in 2008 (Non-Patent Document 8).
More specifically describing their study, a position 2 nitro group or trimethyl ammonio group of the pyridine derivative expressed by the following chemical formula is fluorinated and purified by the HPLC so that an 18 F prosthetic group having a high purity is obtained, and the 18 F prosthetic group was subjected to the Huisgen reaction with a compound to be 18 F-labeled (azidated peptide precursor) in the presence of a catalytic system including TBTA, Cu (CH 3 CN) 4 PF 6 and di-isopropyl ethylamine. The quantity of the compound to be 18 F-labeled used in their study was, however, 1,400 nmol. This is still a large quantity which needs to be reduced.
In recent years, the gene therapy based on such phenomena as antisense, antigene, decoy, and RNA interference is increasingly progressing. There are ongoing approaches for the gene therapy using natural nucleic acids (DNA, RNA) or artificial nucleic acids having better pharmacological kinetics and physiological activities than natural nucleic acids (DNA, RNA) (for example, 2′-0-MeRNA, phosphorothioate oligo, BNAs, LNA). When it succeeds to label the oligonucleotide of any natural or artificial nucleic acid with 18 F and administer the 18 F-labeled oligonucleotide to a human or an experimental animal as a PET probe to measure intra-body kinetics using a PET camera, studies and researches of oligonucleotides are expected to further advance, accelerating the development of pharmaceutical products in which the technique is leveraged. Further, once the “double strand with complementary strand”, which is a characteristic phenomenon of oligonucleotides, can be observed in vivo by using the 18 F-labeled oligonucleotide (in vivo hybridization), it is facilitated to measure an in-vivo mRNA expression level. This technique is broadly applicable to diagnostics of diseases, and studies and researches of medicine and pharmacy. To meet the needs described so far, the oligonucleotide 18 F-labeling method was so far often studied and reported (for example, Non-Patent Documents 9 to 14).
PRIOR ART DOCUMENTS
Patent Document
Patent Document 1: WO2006/116629
Non-Patent Documents
Non-Patent Document 1: Marik, J.; Sutcliffe, J. L. Tetrahedron Lett. 2006, 47, 6681-6684.
Non-Patent Document 2: Hausner, S. H.; Marik, J.; Gagnon, M. K. J.; Sutcliffe, J. L. J. Med. Chem. 2008, 51, 5901-5904.
Non-Patent Document 3: Kim, D. H.; Choe, Y. S.; Jung, K. -H.; Lee, K. -H.; Choi, J. Y.; Choi, Y.; Kim, B. -T. Arch. Pharm. Res. 2008, 31, 587-593.
Non-Patent Document 4: Glaser, M.; Arstad, E. Bioconjugate Chem. 2007, 18, 989-993.
Non-Patent Document 5: Sirion, U.; Kim, H. J.; Lee, J. H.; Seo, J. W.; Lee, B. S.; Lee, S. J.; Oh, S. J.; Chi, D. Y. Tetrahedron Lett. 2007, 48, 3953-3957.
Non-Patent Document 6: Li, Z. B.; Wu, Z.; Chen, K.; Chin, F. T.; Chen, X. Bioconjugate Chem. 2007, 18, 1987-1994.
Non-Patent Document 7 Ramenda, T.; Bergmann, R.; Wuest, F. Lett. Drug Des. Discovery 2007, 4, 279-285.
Non-Patent Document 8 Inkster, J. A. H.; Guerin, B.; Ruth. T. J.; Adam, M. J. J. Labelled Compd. Radiopharm. 2008, 51, 444-452.
Non-Patent Document 9: Dolle, F.; Hinnen, F.; Vaufrey, F.; Tavitian, B.; Crouzel, C. J. Labelled Compd. Radiopharm. 1997, 39, 319-330.
Non-Patent Document 10: Kuhnast, B.; Dolle, F.; Terrazzino, T.; Rousseau, B.; Loc'h, C.; Vaufrey, F.; Hinnen, F.; Doignon, I.; Pillon, F.; David, C.; Crouzel, C.; Tavitian, B. Bioconjugate Chem. 2000, 11, 627-636.
Non-Patent Document 11: Kuhnast, B.; de Bruin, B.; Hinnen, F.; Tavitian, B.; Dolle, F. Bioconjugate Chem. 2004, 15, 617-627.
Non-Patent Document 12: Hedberg, E.; Langstrom, B. Acta Chem. Scand. 1997, 51, 1236-1240.
Non-Patent Document 13: Hedberg, E.; Langstrom, B. Acta Chem. Scand. 1998, 52, 1034-1039.
Non-Patent Document 14: Christopher, W. L.; VanBrocklin, H. F.; Taylor, S. E. J. Label. Compd. Radiopharm. 2002, 45, 257-268.
SUMMARY OF THE INVENTION
Problem to be Solved by the Invention
As described so far, variously different 18 F-labeled azide compounds and 18 F-labeled alkyne compounds were synthesized to be used as the 18 F prosthetic group to perform the 18 F-labeling through the Huisgen reaction. Further, kinetics of the 18 F-labeled compounds were studied by the PET. However, it was always necessary to use a large quantity of acetylene group-modified substrates as a counterpart of the reaction in the case of the 18 F-labeled azide compounds, and it was always necessary to use a large quantity of azide group-modified substrates as a counterpart of the reaction in the case of the 18 F-labeled alkyne compounds probably because of a reason described below.
The Huisgen reaction per se is received in the field of organic chemistry as an easy-to-handle reaction that can rapidly and easily advance when an azide compound and alkyne are simply mixed with each other in the presence of a copper (I) catalyst. However, the Huisgen reaction used in combination with the 18 F-labeling, which is totally different to the Huisgen reaction alone, is very difficult to perform because a cyclotron can only produce a very small quantity of 18 F, leaving no choice but to use a very low-concentrated 18 F prosthetic group. According to the reaction kinetics, a reaction rate is calculated from the function of a reaction rate constant and a reaction substrate. When the low-concentrated 18 F prosthetic group is used for the Huisgen reaction, therefore, it is necessary to choose any reaction system having a large reaction rate constant or increase the concentration of any compound as a labeling target. However, none of the conventional reaction systems was designed to have a substantially large reaction rate constant. Under the circumstances, there was no option but to increase the concentration of any compound to be labeled. Therefore, the quantity of any compound to be labeled was inevitably increased. In the case where the compound to be labeled is such a material that requires considerable time and cost when isolated from natural products or variously synthesized in a large quantity such as oligopeptides or oligonucleotides, only a limited number of PET images may be captured, however, any full-scale PET studies using a number of sequences of oligopeptides or oligonucleotides are still difficult. So far, there is no known example in which oligonucleotides were 18 F-labeled through the Huisgen reaction.
The Non-Patent Documents 9 to 14 report the oligonucleotide 18 F-labeling studies without using the Huisgen reaction. Employing any of the methods reported in these documents for performing the PET, it is still necessary to prepare a large quantity of oligonucleotide precursors that requires considerable time and cost for obtaining a large quantity and a wide variety. Therefore, the reported methods were not applicable to practical use. Further, these methods can only perform the 18 F-labeling of the 5′ end or 3′ end of oligonucleotide, while failing to perform the 18 F-labeling of any other sites thereof. These facts resulted in a small quantity of oligonucleotide precursors that can be used, leading to a strong demand for an 18 F-labeling method that allows a large number of options for parts to be labeled.
The present invention was accomplished to solve the conventional problems. The present invention provides an 18 F-labeled azide compound usable in the Huisgen reaction which enables 18 F-labeling although only a small quantity of alkyne compound is available as a counterpart substrate, more specifically the 18 F-labeled azide compound enabling the PET to be applied to peptides or oligonucleotides and enabling the 18 F-labeling of any sites of oligonucleotide other than the 5′ end or 3′ end thereof, a reagent for 18 F-labeling, and a method for 18 F-labeling of an alkyne compound using the same.
Means for Solving the Problem
To solve the conventional problems, the inventors of the present invention discussed preferable designs of an 18 F-labeled azide compound when applied to the PET. Prior to the 18 F-labeling, a compound having a small molecular weight is preferably selected to minimize any impact on in vivo kinetics of a compound subjected to the PET. An ideal example of the compound in this regard could be 18 FCH 2 N 3 . However, this material having a low boiling point is easily gasified, therefore, practically unusable to avoid the risk of radiation exposure. Therefore, the compound to be selected preferably has a relatively high boiling point. The compound to be selected is desirably capable of absorbing strong UV that can be detected by a UV detector of a high-performance liquid chromatography (hereinafter, called “HPLC”) apparatus to facilitate post-synthesis purification and concentration, and designed to have such a boiling point that melted fractions will not be volatilized when concentrated. Further, the compound is desirably synthesizable in one stage from a precursor of the 18 F-labeled azide compound and chemically stable.
A candidate of the compound meeting the required properties adduced by the inventors of the present invention is a phenyl azide compound labeled with 18 F. Because of a difficulty in converting hydrogen of a phenyl group into fluorine, the inventors discussed introduction of a fluoroalkyl group in the phenyl group and tried to figure out a design that allows a smallest fluoromethyl group to be introduced. The inventors synthesized a compound which conforms to the design, and performed the Huisgen reaction between the compound and acetylene group-modified oligonucleotide. Then, they found out that their approach solves the conventional problems, and finally completed the present invention.
An 18 F-labeled azide compound according to the present invention is expressed by the following structural formula 1).
The 18 F-labeled azide compound has an azide group and thereby generates the Huisgen reaction with a compound having a carbon-carbon triple bond. Because of the structural characteristic, the 18 F-labeled azide compound can be used as a reagent for 18 F-labeling.
According to the finding by the inventors of the present invention, the 18 F-labeled azide compound can be transformed speedily and easily into an 18 F-labeled triasole derivative by the Huisgen reaction with an alkyne compound in the presence of a copper compound catalyst. As compared to the Huisgen reaction using the conventional 18 F-labeled azide compound, this reaction advances although the alkyne compound, which is a counterpart substrate, is low-concentrated. Therefore, this reaction is applicable to the 18 F-labeling of peptides and oligonucleotides characterized in difficulty of preparing a large quantity of substrates.
The reaction is preferably performed in the presence of ascorbate and an amine-based base by using a mixed solvent including water and a water-soluble organic solvent as s reaction solvent. Examples of the water-soluble organic solvent are; diphenyl sulfone, dimethyl sulfoxide, benzophenone, tetrahydrothiophene-1,1-dioxide, N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, N-methyl-ε-caprolactam, 1,3-dimethyl-2-imidazolidinone, methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol and t-butanol. Of these examples, dimethylsulfoxide (hereinafter, called DMSO) is particularly a suitable example because of its remarkable resolving power, good safety, less corrosiveness, good handleability because of its moderate melting point and boiling point, and good yield. Examples of the amine-based base are; diisopropyl ethylamine, triethylamine, pyridine, 2,6-lutidine, and (tris((1-benzyl-1H-1,2,3-triasole-4-yl)methyl)amine. Of these examples, (tris((1-benzyl-1H-1,2,3-triasole-4-yl)methyl)amine (hereinafter, called “TBTA”) is a particularly preferable example.
The alkyne compound used in an alkyne compound 18 F-labeling method according to the present invention can be a nucleotide derivative. An oligonucleotide is a biological molecule applicable to pharmaceutical products because of its physiological activity based on such phenomena as antisense, antigene, decoy, and RNA interference. Further, there are ongoing studies of artificial nucleic acids having better pharmacological kinetics and physiological activities than natural nucleic acids (DNA, RNA) (for example, 2′-0-MeRNA, phosphorothioate oligo, BNAs, LNA). When it succeeds to label the oligonucleotide of any natural or artificial nucleic acid with 18 F and administer the 18 F-labeled oligonucleotide to a human or an experimental animal as a PET probe to measure intra-body kinetics using a PET camera, studies and researches of oligonucleotides are expected to further advance, accelerating the development of pharmaceutical products in which the technique is leveraged.
The alkynyl group-modified oligonucleotide enables the 18 F-labeling of not only the 5′ end or 3′ end of oligonucleotide but also any other sites thereof. Thus, any sites of oligonucleotide other than the 5′ end or 3′ end thereof can be successfully 18 F-labeled.
DESCRIPTION OF EMBODIMENTS
Hereinafter, examples of the present invention are described in detail.
Synthesis of 4-methyl benzenesulfonic acid 4-azide benzyl (3a)
First, 4-methyl benzenesulfonic acid 4-azide benzyl (3a), which is used as a precursor of the 18 F-labeled azide compound according to the present invention, was synthesized by the method expressed by the following reaction formula.
4-azidebenzyl alcohol (2a) (prepared by the method recited in (Andersena, J. et al.; Synlett 2005, 14, 2209-2213) (149 mg, 1.00 mmol) was dissolved in methylene chloride (5.0 mL), and pyridine (0.162 mL, 2.00 mmol) and p-toluenesulfonic acid (343 mg, 1.05 mmol) were added thereto at 0° C. After the mixed matter was agitated for 30 minutes, water is added thereto, and the resulting solution was quenched. An aqueous layer of the solution was removed therefrom, and an organic layer thereof was washed sequentially with 1 mol/L hydrochloric acid, saturated sodium acid carbonate water solution, and saturated salt solution and then dried with anhydrous sodium sulfate. Then, the solvent was distilled away under a reduced pressure. A residue thereby obtained was mixed with diethyl ether (3 mL) and then filtered through a plug of cotton to remove any insoluble matters therefrom. The filtered solution was mixed with hexane (5 mL) and agitated, and then left at rest for 30 minutes so that crystals were deposited. A supernatant liquid thereby obtained was removed from the solution by means of a pipette. The crystals were washed with hexane and then dried under a reduced pressure so that 4-methyl benzenesulfonic acid 4-azide benzyl (3a) (218 mg, 0.719 mmol, 71.9%) was obtained in the form of colorless crystals. Below are recited 1 H-NMR spectrum, 13 C-NMR spectrum, and mass spectrum (EI) of the obtained material.
1 H-NMR (400 MHz, CDCl 3 )
δ: 2.45 (3H, s), 5.02 (2H, s), 6.97 (2H, d, J=8.3 Hz), 7.24 (3H, d, J=8.3 Hz), 7.34 (2H, d, J=8.3 Hz), 7.79 (2H, d, J=8.3 Hz)
13 C-NMR (100 MHz, CDCl 3 )
δ: 21.7, 71.3, 119.2, 127.9, 129.9, 129.9, 130.3, 133.3, 141.0, 144.9
HRMS (EI)
calc 303.0677 obs 303.0650
Synthesis of 4-methyl benzenesulfonic acid 3-azide benzyl (3b)
In a manner similar to the description given earlier, 4-methyl benzenesulfonic acid 3-azide benzyl (3b), which is an isomer of the compound (3a), was obtained by the yield of 51.8%.
Below are recited IR spectrum, 1 H-NMR spectrum, 13 C-NMR spectrum, mass spectrum (EI), and element analysis of the obtained material.
IR (film, KBr)
2114, 1593, 1489, 1452, 1360, 1292, 1177, 945, 835, 814, 781, 665 cm −1
1 H-NMR (400 MHz, CDCl 3 )
δ: 2.45 (3H, s), 5.03 (2H, s), 6.85 (1H, s), 6.97 (1H, d, J=7.8 Hz), 7.03 (1H, d, J=7.8 Hz), 7.30 (1H, t, J=7.8 Hz), 7.33 (2H, d, J=8.5 Hz), 7.79 (2H, d, J=8.5 Hz)
13 C-NMR (100 MHz, CDCl 3 )
δ: 21.6, 71.0, 118.8, 119.5, 124.7, 128.0, 129.9, 130.1, 133.1, 135.3, 140.5, 145.0
LRMS (EI)
calc 303 obs 303
Element Analysis
calc. H, 4.32%; C, 55.43%; N, 13.85%.
obs. H, 4.32%; C, 55.59%; N, 13.89%.
Synthesis of Acetylene Group-Modified Oligonucleotide
Synthesis of Acetylene Group-Modified Oligonucleotide (4a)
Next, an acetylene group-modified oligonucleotide (4a) (sequence in the formula presents natural DNA) was synthesized by the method recited in the following literature (S. Obika, et al. Bioorganic and Medicinal Chemistry Letters, 2009, 19, 3316-3319) as an alkyne compound used as the substrate of the Huisgen reaction.
Synthesis of Acetylene Group-Modified Oligonucleotide (4b)
Then, an acetylene group-modified oligonucleotide precursor (4b) (underscored part in the following chemical formula represents 2′,4′-BNA, and other parts represent natural DNA, “s” in the formula represent a phosphorothioate bond) having 2′,4′-BNA (also called LNA, see the following chemical formula) and a phosphorothioate bond was synthesized as an artificial nucleic acid by the method recited in the following literature (S. Obika, et al. Bioorganic and Medicinal Chemistry Letters, 2009, 19, 3316-3319).
Synthesis of Acetylene Group-Modified Oligonucleotide (4b)
Further, an acetylene group-modified oligonucleotide precursor (4c) (underscored part in the following chemical formula represents 2′,4′-BNA, and other parts represent natural DNA) in which 2′ and 4′ positions of deoxyribose are cross-linked was synthesized by the method recited in the following literature (S. Obika, et al. Bioorganic and Medicinal Chemistry Letters, in press, oi:10.1016/j.bmcl.2009.04.063).
Synthesis of 18 F-Labeled Azide Compound and 18 F-Labeling of Acetylene Group-Modified Oligonucleotide
Then, the 18 F-labeled azide compound was synthesized by means of the 4-methyl benzenesulfonic acid-4-azide benzyl (3a) and 4-methyl benzenesulfonic acid-3-azide benzyl (3b) synthesized earlier. Further, a coupling reaction was performed between the 18 F-labeled azide compound and the acetylene group-modified oligonucleotide through the Huisgen reaction.
Example 1
In an example 1, a tosylate group of the 4-methyl benzenesulfonic acid 4-azide benzyl (3a) was substituted with 18 F to synthesize an 18 F-labeled azide compound (1a). Then, the coupling reaction was performed between the compound and the acetylene group-modified oligonucleotide (4a) through the Huisgen reaction. Hereinafter, the example 1 is described in detail.
Synthesis of 18 F-Labeled Azide Compound (1a)
The [ 18 O] water (approximately 2 mL, supplied by TAIYO NIPPON SANSO CORPORATION) was irradiated by a 12-meV electronic beam (HM-12S supplied by Sumitomo Heavy Industries, Ltd., current value: 50 μA, for 30 minutes) so that [ 18 F] fluorine ions were generated. An approximately 50-GBq fluoroion [ 18 O] water solution thus obtained was guided in a labeling synthesis apparatus (GNMS-α, supplied by GNMS-ALPHA DAINIPPON SEIKI CO., LTD.) installed in a hot cell, and let through an anion-exchange resin cartridge (SAIKA-SPE SAX-30, supplied by AiSTI SCIENCE). The [ 18 F] fluorine ions adsorbed thereto were removed by carbonic acid hydrogenion tetra N-butyl ammonium (0.025 mol/L, 80% acetonitrile/water solution, 0.6 mL), and washed with 0.6 mL of acetonitrile. Then, the [ 18 F] fluoroion solution was guided in a first reaction container and heated to 110° C. to be dried and solidified under a reduced pressure in helium flow, and further azeotropically dried with acetonitrile (1 mL). A residual thereby obtained is mixed with an acetonitrile (1 mL) solution of 4-methyl benzenesulfonic acid 4-azide benzyl (1a) (6.0 mg) and subjected to a reaction at 85° C. for five minutes. A radiochemical yield obtained by analysis at the time was 99%. The reaction mixture was isolated and purified by semi-preparative HPLC (conditions: COSMOSIL MS-11, 10×250 mm column supplied by NAKALAI TESQUE INC., dipped in 40% acetonitrile/water for six minutes and then dipped in 60% acetonitrile/water for 14 minutes, flow rate: 1 mL/min., target material was eluted after retained for 15 to 16 minutes).
18 F-Labeling of Acetylene Group-Modified Oligonucleotide (4a) Using 18 F-Labeled Azide Compound (1a)
All the fractions including the 18 F-labeled azide compound (1a) thus isolated and purified were gathered and transferred to a second reaction container already containing therein 0.18 mL of DMSO. Under a reduced pressure in helium flow while being heated to 40° C., acetonitrile was carefully volatilized. To the DMSO water-mixed solution (about 0.5 mL) of the 18 F-labeled azide compound (1a) thus obtained was added a buffer (100 mmol/L sodium biphosphate buffer, pH: 7.0, 60 μL), acetylene group-modified oligonucleotide (4a) (0.50 mmol/L water solution, 40 μL), copper sulfate (50 mmol/L water solution, 12 μL), TBTA (tris(1-benzyl-1H-1,2,3-triasole-4-yl)methyl)amine, 50 mmol/L DMSO solution (6 μL), and sodium ascorbate (50 mmol/L water solution, 12 μL) to generate a reaction at 40° C. for 15 minutes. A radiochemical yield obtained by analysis at the time was 92%. The reaction mixture was diluted with water (0.3 mL), and then isolated and purified by semi-preparative HPLC (conditions: COSMOSIL AR-11, 10×250 mm column supplied by NAKALAI TESQUE INC., column temperature: 50° C., linearly gradient in a 10-20% CH3CN/0.1 mol/L TEAA buffer for 20 minutes, flow rate: 4 mL/min., target material was eluted after retained for 14 to 15 minutes). All the fractions including targeted [ 18 F] (5a) were gathered, and acetonitrile was evaporated under a reduced pressure, so that a TEAA buffer solution (5 mL) of 18 F-labeled oligonucleotide (5a) was obtained.
Time for and Yield of Synthesis of 18 F-Labeled Oligonucleotide (5a)
A length of time required for synthesizing the 18 F-labeled oligonucleotide (5a) and a yield thereof was; synthesis time: 84 minutes, radiation of isolated (5a): 2.53 GBq, specific radioactivity: 2366 GBq/μmol, chemical purity (UV 260 nm): 95%, radiation chemical purity: 87%, radiochemical yield based on [ 18 F] fluorine ions: 5.2% (not decay-compensation), and 8.6% (decay-compensated).
The synthesizing method can desalinate or concentrate TEAA if necessary. Below are described in detail desalination steps.
The TEAA buffer solution of [ 18 F] (5a) was let through Sep-Pak Plus C18 (supplied by Nihon Waters K.K., preconditioned with 40 mL of EtOH and 40 mL of water) and washed with water (5 mL) twice, and then dried for one minute in nitrogen gas flow so that [ 18 F] (5a) was eluted with ethanol (1 mL). Then, the ethanol was volatilized in nitrogen gas flow to obtain a concentrated [ 18 F] (5a) water solution. This water solution was diluted with a suitable volume of physiological salt solution so that a solution to be administered to animals was prepared. Although the process time further increased by 30 minutes, 90% was recovered (decay-compensated).
Example 2
Similarly to the synthesis in the example 1, a tosylate group of the 4-methyl benzenesulfonic acid-3-azide benzyl (3b) was substituted with 18 F to synthesize an 18 F-labeled azide compound (1b). Then, the coupling reaction was performed between the compound and the acetylene group-modified oligonucleotide (4a) through the Huisgen reaction.
Although not described in the examples because it is explicitly known from the technical common knowledge, an 18 F-labeled ortho-azide compound can be obtained through an operation performed similarly to the example 1 by using 2-azidebenzyl alcohol in place of 4-azidebenzyl alcohol (2a) used as a parent material in the example 1.
Synthesis of 18 F-Labeled Azide Compound (1b)
Similarly to the synthesis of the 18 F-labeled azide compound (1a) in the example 1, the 18 F-labeled azide compound (1b) was synthesized.
Labeling of Acetylene Group-Modified Oligonucleotide (4a) Using 18 F-Labeled Azide Compound (1b)
Similarly to the method described in the example 1, the acetylene group-modified oligonucleotide (4a) was labeled by using the 18 F-labeled azide compound (1b). The coupling reaction was performed between the 18 F-labeled azide compound (1b) and the acetylene group-modified oligonucleotide (4a) through the Huisgen reaction, so that a TEAA buffer solution (5 mL) of 18 F-labeled oligonucleotide (5b) was obtained.
Time for and Yield of Synthesis of 18 F-Labeled Oligonucleotide (5b)
A length of time required for synthesizing the 18 F-labeled oligonucleotide (5b) and a yield thereof were; synthesis time: 83 minutes, radiation of isolated (5b): 2.12 GBq, specific radioactivity: 1809 GBq/μmol, chemical purity (UV 260 nm): 99%, radiation chemical purity: 93%, radiochemical yield based on [ 18 F] fluorine ions: 4.2% (not decay-compensation), and 7.2% (decay-compensated).
Example 3
In an example 3, similarly to the synthesis in the example 2, a tosylate group of the 4-methyl benzenesulfonic acid-3-azide benzyl (3b) was substituted with 18 F to synthesize the 18 F-labeled azide compound (1b). Then, the coupling reaction was performed between the compound and the acetylene group-modified oligonucleotide (4b) through the Huisgen reaction.
18 F-Labeling of Acetylene Group-Modified Oligonucleotide (4b)
The coupling reaction was performed between the 18 F-labeled azide compound (1b) thus synthesized and the acetylene group-modified oligonucleotide (4b) through the Huisgen reaction similarly to the method in the example 2, so that an 18 F-labeled oligonucleotide (5c) was obtained.
Time for and Yield of Synthesis of 18 F-Labeled Oligonucleotide (5c)
A length of time required for synthesizing the 18 F-labeled oligonucleotide (5c) and a yield thereof were; synthesis time: 95 minutes, radiation of isolated (5c): 0.862 GBq, specific radioactivity: 762 GBq/μmol, chemical purity (UV 260 nm): 96%, radiation chemical purity: >99%, radiochemical yield based on [ 18 F] fluorine ions: 1.7% (not decay-compensation), and 3.1% (decay-compensated).
Example 4
In an example 4, similarly to the synthesis in the example 2, a tosylate group of the 4-methyl benzenesulfonic acid-3-azide benzyl (3b) was substituted with 18 F to synthesize the 18 F-labeled azide compound (1b). Then, the coupling reaction was performed between the compound and the acetylene group-modified oligonucleotide (4c) through the Huisgen reaction.
18 F-Labeling of Acetylene Group-Modified Oligonucleotide (4c)
The coupling reaction was performed between the 18 F-labeled azide compound (1b) thus synthesized and the acetylene group-modified oligonucleotide (4b) through the Huisgen reaction, so that an 18 F-labeled oligonucleotide (5d) was obtained.
Time for and Yield of Synthesis of 18 F-Labeled Oligonucleotide (5d)
A length of time required for synthesizing the 18 F-labeled oligonucleotide (5d) and a yield thereof were; synthesis time: 83 minutes, radiation of isolated (5c): 1.66 GBq, specific radioactivity: 3205 GBq/μmol, chemical purity (UV 260 nm): 98%, radiation chemical purity: 96%, radiochemical yield based on [ 18 F] fluorine ions: 3.3% (not decay-compensation), and 5.6% (decay-compensated).
Comparison to the Prior Art
It was confirmed form the results of the examples 1 to 3 that the alkyne compound can be 18 F-labeled at a high yield when the Huisgen reaction is performed between the 18 F-labeled azide compounds (1a) and (1b) which are very dilute and the acetylene group-modified oligonucleotides which are very dilute in the presence of the copper compound catalyst. Table 1 shows required quantities and concentrations of compounds to be 18 F-labeled in the conventional 18 F-labeling method and the 18 F-labeling method according to the present invention. As compared to the conventional 18 F-labeling method, the 18 F-labeling using the 18 F-labeled azide compounds (1a) and (1b) according to the examples 1 to 3 can be accomplished although the required quantities and concentrations of the compounds to be 18 F-labeled are significantly small as is clearly known from the table.
TABLE 1 quantity of concentration compound to be of compound to 18 F-labeled be 18 F-labeled (nmol) (μmol/L) oligonucleotide method recited in the Non-patent Document 9 100-200 method recited in the Non-patent Document 10 200-400 200-400 method recited in the Non-patent Document 11 141-275 353-688 method recited in the Non-patent Document 12 70 778 method recited in the Non-patent Document 13 52-140 520-1040 method recited in the Non-patent Document 14 76-600 688-5503 Huisgen reaction method recited in the Non-patent Document 1 300 136 method recited in the Non-patent Document 2 400 533 method recited in the Non-patent Document 3 48700 37462 method recited in the Non-patent Document 4 3400 17000 method recited in the Non-patent Document 5 15000 30000 method recited in the Non-patent Document 6 678 565 method recited in the Non-patent Document 7 1000 12500 method recited in the Non-patent Document 8 1400 9333 18 F-labeled azide compounds (1a) and (1b) 10-20 10-40 The Non-Patent Documents 1 to 8 recite the 18 F-labeling methods using the Huisgen reaction, whereas the Non-Patent Documents 9 to 14 recite the conventional methods wherein oligonucleotide is 18 F-labeled.
Reaction Conditions
To perform the 18 F-labeling through the Huisgen reaction using the 18 F-labeled azide compound according to the present invention, the synthesis is preferably performed remotely by using a mechanical device to avoid exposure to radiation. To serve the purpose, it is desirable to use a labeling synthesis apparatus in a shielded draft. As a result, it becomes necessary to meet within a limited amount of time such a need to obtain a trace level of 18F-labeled azide compound having a very high purity from large quantities of precursors, resolved matters, and different reagents. Moreover, the Huisgen reaction per se should speed up and achieve a high yield. To meet all of these needs, optimal reaction conditions were thoroughly discussed.
Optimal Conditions for Huisgen Reaction
To efficiently perfrom the Huisgen reaction, the inventors focused on a reaction rate and discussed optimal conditions that allow the reaction speed to be as high as possible because the present invention synthesizes only a small quantity of 18 F-labeled azide compound, making it indispensable to find such conditions that two very dilute substrates can be reacted under moderate conditions.
The inventors discussed the reaction conditions by using a non-labeled 19 F azide compound as the substrate of the alkyne compound, a model of which is N-(prop-2-ynyl)benzamide. First, the high-concentrated substrates were subjected to the Huisgen reaction for screening of organic solvents most suitable for the reaction. 1 mM/L copper sulfate was used as a catalyst, 2 mM/L sodium ascorbate was used as a reducer, 1 mM/L TBTA was used in the Huisgen reaction. Further, the organic solvents were variously changed at the capacity ratio of water to organic solvent=3 to 7.
As a result, it was learnt that the addition of the non-protic solvent improved the yield, and the DMSO particularly improved the yield as illustrated in Table 2. Further, it was clearly known from the comparison of the entries 5 and 6 that the addition of TBTA dramatically improved the yield.
TABLE 2
entry
solvent a)
yield (%) b)
1
dioxane
94
2
DMF
82
3
CH3CN
1
4
t-BuOH
95
5
DMSO
97
6
DMSO c)
8
a) organic solvent:H 2 O = (7:3)
b) yield obtained from HPLC
c) TBTA not added
The inventors further looked into the reaction conditions in the foregoing reaction when a dilute solution is used. Similarly to concentrations conventionally used in radiation labeling tests, they changed the reaction conditions using a more dilute substrate (100 μmol/L N-(prop-2-ynyl)benzamide and 50 μmol/L non-labeled 19 F azide compound (1b)). Then, it was learnt that the yield improved when the TBTA concentration was equal to or higher than 100 μM/L, and the yield was better when (TBTA concentration)/(Cu concentration) was ½ than 1. Thus, it was confirmed that the ratio less than 1 could favorably improve the yield. Further, the yield is better when the reaction temperature is set to 40° C. than room temperature.
TABLE 3
entry
Na Asc
TBTA
Cu
temperature
yield (%) a)
1
1000
1000
1000
room temperature
71
2
1000
500
1000
room temperature
79
3
500
250
500
room temperature
81
4
200
100
200
room temperature
67
5
100
50
100
room temperature
41
6
1000
500
1000
40° C.
94
7
500
250
500
40° C.
87
a) yield obtained from HPLC
reaction time: 15 minutes
reaction solvent: DMSO/H 2 O=20/80, 10 mmol/L, sodium phosphate buffer pH7
Under the conditions of the entry 2 in Table 3, the yield when pH of the sodium phosphate buffer is variously changed was checked. As illustrated in FIG. 4 , the yield showed remarkable improvements when pH was 6.5 to 7.5, and marked the highest result when pH was around 7.
TABLE 4
pH
yield (%)
6.5
67
7
79
7.5
68
Under the conditions of the entry 2 in Table 3, the yield when the DMSO concentration is variously changed was checked. As illustrated in FIG. 5 , the yield showed remarkable improvements when the DMSO volume percent is at least 30%.
TABLE 5
DMSO (volume %)
yield (%)
10
82
20
79
30
92
40
90
50
92
PET Images
The 18 F-labeled oligonucleotide (5a) obtained in the example 1 was administered to a rat, and a PET image was obtained. More specifically, a physiological salt solution containing 45 MBq of the 18 F-labeled oligonucleotide (5a) is administered to an SD rat (8 weeks old, weight: 252 g) under anesthesia though a caudal vein, and an image of the rat was obtained by MicroPET Focus-220, PET apparatus for animals supplied by SIEMENS. FIG. 1 shows a whole-body image of the rat showing 30-minute accumulation after 120 minutes passed since the probe administration (Maximum Intensity Projection image). The image teaches that the administered 18 F-labeled oligonucleotide (5a) was promptly metabolized in blood and excreted in urine. It is read from the image the deposition of intensive radiation in the bone texture of the whole body, which is, however, considered to result from F-ions generated as the 18 F-labeled oligonucleotide (5a) is metabolized.
The 18 F-labeled oligonucleotides (5b), (5c), and (5d) were similarly administered to rats, and PET images of the rats were obtained. FIGS. 2 to 4 show whole-body images of the rats showing 30-minute accumulation after 120 minutes passed since the administration (Maximum Intensity Projection image). These drawings teach that the 2′,4′-BNA-transformed (5d), because its metabolic rate in blood slows down, is deposited in their kidneys and urinary bladders, and the radioactivity in their bone textures is deteriorated, and further teaches that the 2′,4′-BNA-transformed (5c) having its skeleton bonded to phosphorothioate is metabolized at even a lower metabolic rate and deposited in the kidneys and urinary bladders, and the radioactivity in the bone textures is further deteriorated.
As described so far, when the 18 F-labeled oligonucleotide according to the present invention is used, the effects of artificial nucleic acids, such as 2′,4′-BNA-transformed oligonucleotide and phosphorothioate oligonucleotide, can be directly observed. Thus, the present invention is advantageous in that, for example, nuclease tolerance and distribution to tissues can be directly observed in vivo in the studies of the gene therapy using RNA interference. Therefore, the present invention can be leveraged as a technically advantageous tool in the research and development of oligonucleotide pharmaceutical products.
The present invention is not necessarily limited to the exemplary embodiment and examples described so far. The present invention includes various modified embodiments as far as they stay within the Scope of Claims and can be easily assumed by the ordinarily skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a whole-body image (MIP image) of an SD rat showing 30-minute accumulation after 120 minutes passed since an 18 F-labeled oligonucleotide (5a) is administered to the SD rat though a caudal vein.
FIG. 2 is a whole-body image (MIP image) of a SD rat showing 30-minute accumulation after 120 minutes passed since an 18 F-labeled oligonucleotide (5b) is administered to the SD rat though a caudal vein.
FIG. 3 is a whole-body image (MIP image) of a SD rat showing 30-minute accumulation after 120 minutes passed since an 18 F-labeled oligonucleotide (5c) is administered to the SD rat though a caudal vein.
FIG. 4 is a whole-body image (MIP image) of a SD rat showing 30-minute accumulation after 120 minutes passed since an 18 F-labeled oligonucleotide (5d) is administered to the SD rat though a caudal vein.
INDUSTRIAL APPLICABILITY
The present invention can provide an advantageous means in the field of medicine where nucleic acid oligomer is used, for example, RNA drug development expected to be launched in individualized medicine.
|
The present invention provides an 18 F-labeled azide compound usable in the Huisgen reaction which enables 18 F-labeling although only a small quantity of alkyne compound is available as a counterpart substrate, more specifically the 18 F-labeled azide compound enabling the PET to be applied to peptides or oligonucleotides and enabling the 18 F-labeling of any sites of oligonucleotide other than the 5′ end or 3′ end thereof, a reagent for 18 F-labeling, and a method for 18 F-labeling of an alkyne compound using the same.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATION
This application is a non-provisional application based on provisional application Ser. No. 61/158,712, filed Mar. 9, 2009, the entire disclosure of which is hereby incorporated by reference
BACKGROUND OF THE INVENTION
This invention relates to fuel cells arranged in a fuel cell stack and, in particular, to a fuel cell stack design and method configured to enhance overall fuel utilization and control temperature distribution in the stack and thereby provide an increased service life for the stack.
A fuel cell is a device which directly converts chemical energy stored in hydrocarbon fuel into electrical energy by means of an electrochemical reaction. Generally, a fuel cell comprises an anode and a cathode separated by a member which serves itself to conduct electrically charged ions or is adapted to hold an electrolyte which conducts electrically charged ions. In order to produce a useful power level, a number of individual fuel cells are stacked in series with an electrically conductive separator plate separating the cells.
Before undergoing the electrochemical reaction in the fuel cell, hydrocarbon fuels such as methane, coal gas, etc. are typically reformed to produce hydrogen for use in the anode of the fuel cell. In internally reforming fuel cells, a steam reforming catalyst is placed within the fuel cell stack to allow direct use of hydrocarbon fuels without the need for expensive and complex reforming equipment. In addition, the endothermic reforming reaction can be used advantageously to help cool the fuel cell stack.
Internally reforming fuel cells employ direct internal reforming and indirect internal reforming. Direct internal reforming is accomplished by placing the reforming catalyst within the active anode compartment. Direct internal reforming thus directly exposes the catalyst to the electrolyte of the fuel cell, which can lead to deactivation of the catalyst and an eventual degradation of the fuel cell's performance. Improvements have been made to the direct internal reforming technique to reduce electrolyte contamination, but these improvements are accompanied by high costs due to the complexity of the fuel cell design, special materials requirements and a reduction in the effectiveness of the reforming catalyst.
The second reforming technique, indirect internal reforming, is accomplished by placing the reforming catalyst in an isolated chamber within the fuel cell stack and routing the reformed gas from this chamber into the anode compartment of the fuel cell. With this technique, the need for separate ducting systems raises the cost of the fuel cell stack and also makes the system susceptible to fuel leaks.
The current state of the art uses a hybrid assembly in which the fuel cell stack has both direct and indirect internal reforming and in which external manifolds are used for enclosing and directing the flow of fuel and oxidant gases into the stack. U.S. Pat. No. 6,200,696 and U.S. Patent Application Publication No. 2006/0123705, assigned to the same assignee hereof, disclose examples of such hybrid assemblies. As disclosed in the '696 patent and the 2006/0123705 publication, the hybrid assembly includes one or more fuel reformers for indirect internal reforming of input fuel gas, which receive the input fuel gas and convey it in a U-shaped path while reforming the fuel therein. The assembly of the '696 patent and the 2006/0123705 publication also includes a fuel-turn manifold for redirecting reformed gas outputted by the indirect internal reformers to the anode compartments for further reforming through direct internal reforming and electrochemical conversion. In these assemblies, both the U-shaped flow path in the reformer and the flow through the anode compartments of the fuel cells is in cross-flow, or perpendicular to, the oxidant gas passing through the stack.
Due to the nature of the fuel flow within the fuel reformers, such hybrid assemblies are sometimes susceptible to non-uniformity in their current density distribution and to temperature gradients near the gas exits of the stack. These effects occur as the stack ages and as the catalyst within the stack plates, the Direct Internal Reforming (DIR) catalyst, is deactivated over the course of the service life of the stack. As a result, thermal instability within the stack may occur and may cause non-optimized fuel utilization in the production of electricity. This is especially true given the maximum allowable temperature at which the stack is designed to operate.
It is therefore an object of the present invention to further improve fuel cell stack design and methodology so as to create a fuel flow arrangement which increases the fuel conversion efficiency of the stack.
It is also an object of the present invention to provide a fuel cell stack design and methodology which promotes cooling so as to realize a more uniform temperature distribution, thus increasing the overall efficiency of the fuel cell operation and electricity production and extending the operating life of the stack.
SUMMARY OF THE INVENTION
The above and other objects are realized in a reformer for use in a fuel cell system comprising an enclosure including an inlet port and an outlet port, and a plate assembly supporting reforming catalyst disposed within the enclosure, wherein the outlet port is configured to abut a fuel inlet port of a fuel cell assembly adjacent to the reformer, when the reformer is assembled into the fuel cell system, so that at least a first portion of the fuel reformed by the reformer is supplied directly from the outlet port of the reformer to the inlet port of the fuel cell assembly.
In some embodiments, the reformer is configured to supply all of the fuel reformed thereby to the inlet of the fuel cell assembly adjacent the reformer, while in other embodiments the reformer comprises a further outlet port for outputting a second portion of the fuel reformed by the reformer to the fuel cell manifold when the reformer is assembled into the fuel cell system. The plate assembly of the reformer includes a plurality of sections, including an inlet section communicating with the inlet port, an outlet section communicating with the outlet port and a central section disposed between the inlet section and the outlet section, and the plate assembly further includes a plurality of baffles for directing the fuel flow through the plate assembly. The central section of the plate assembly may include a plurality of zones, each of which communicates with the inlet section and with the outlet section and a plurality of baffles for directing the flow of fuel into each of the zones. The loading density of the reforming catalyst supported by the plate assembly is varied so that the inlet section has a first loading density, the central section has a second loading density which is greater than the first loading density, and the outlet section has a third loading density which is smaller than or equal to the second loading density.
A fuel cell system that includes the reformer is also disclosed. The fuel cell system comprises a plurality of fuel cell assemblies and at least one reformer, forming a fuel cell stack, with the plurality of fuel cell assemblies including at least one reformer-associated assembly and one or more non-reformer-associated assemblies. Each of the reformer-associated assemblies is adjacent to and associated with a reformer. Each reformer is configured to receive fuel through an inlet port and to output at least a first portion of fuel reformed in the reformer through an outlet port directly to the reformer-associated assembly associated with the reformer, and each reformer-associated assembly is configured to output partially spent fuel for use in one or more non-reformer-associated assemblies. In some embodiments, the fuel cell stack includes a fuel inlet face, a fuel outlet face, an oxidant inlet face and an oxidant outlet face and comprises a plurality of manifolds including at least a fuel inlet manifold that sealingly encloses the fuel inlet face of the stack. In such embodiments, each reformer-associated assembly outputs partially spent fuel into the fuel inlet manifold and the fuel inlet manifold is configured to direct the partially spent fuel to the non-reformer-associated assemblies. In some embodiments the reformer-associated assembly includes no reforming catalyst, while the non-reformer-associated assembly supports reforming catalyst for directly reforming the partially spent fuel. A method of operating the fuel cell system that includes at least one reformer and a plurality of fuel cell assemblies is also described.
The above and other objects are also realized in a fuel cell stack having fuel cell assemblies stacked one after the other in a stacking direction and each including an anode part and a cathode part separated by an electrolyte receiving part and stacked in the stacking direction and one or more reforming units interspersed within the stack each between an associated anode compartment and an associated cathode compartment of fuel cell assemblies which follow one another in the stacking direction, each reforming unit and the associated anode compartment being configured such that reformed fuel gas from the reformer is supplied directly to the associated anode compartment where the reformed fuel gas undergoes partial electrochemical conversion in the fuel cell assembly containing the associated anode compartment and each associated anode compartment being further configured such as to make available to the anode compartment of other fuel cell assemblies the part of the reformed fuel gas that does not undergo electrochemical conversion in the fuel cell assembly containing the associated anode part.
In some of the embodiments of the invention, each reformer has an output port in a surface of the reformer in the stacking direction and each associated anode compartment has an input port in a surface of the anode compartment in the stacking direction which communicates with the reformer output port. In certain of these embodiments, an output port of each associated anode compartment is at a fuel inlet face of the fuel cell stack and the input ports of the anode compartments other than the associated anode compartments are also at the fuel inlet face of the stack. In some of these embodiments, a manifold abuts the fuel inlet face of the stack so that reformed fuel gas from the output ports of the associated anode compartments is conveyed by the manifold to the input ports of the anode compartments other than the associated anode compartments.
Additionally, in certain embodiments, the stack has a fuel outlet face opposite the fuel inlet face and the output ports of the anode compartments other that the associated anode compartments are at this fuel outlet face. In these embodiments, the input port of the reformers can be at the fuel inlet face of the stack, the output port of the reformers can have a first part which runs in a first direction running between the fuel inlet and fuel outlet faces of the stack and optionally a second part adjacent the second face of the stack that runs transverse to the first direction. Additionally, in these embodiments, the input ports of the associated anode compartments can likewise run in the first direction running between the fuel inlet and fuel outlet faces of the stack.
Also, in some of these embodiments, the associated anode compartments contain no or a little amount (less than 50 g) of catalyst for reforming fuel gas, while the anode compartments other than the associated anode compartments contain larger amounts (greater than 400 g) of catalyst for reforming fuel gas.
In certain embodiments, the output port of the reformer can have a part which runs along the length of the reformer and a part which runs along the width of the reformer. In some embodiments, the reformer can have an additional output port at a face of the stack.
Additionally, in certain embodiments, the reformers and cathode and anode compartments are configured such that flow of gas through the reformers is counter to the flow of oxidant gas through the cathode compartments, while the flow of gas through the associated anode compartments is co-flow with the flow of gas through the anode compartments and the flow of gas through the anode compartments other that the associated anode compartments is transverse or cross to the flow of gas through the cathode compartments. In other embodiments, the reformers and cathode and anode compartments are configured such that flow of gas through the reformers is counter to the flow of oxidant gas through the cathode compartments, while the flow of gas through the associated anode compartments is co-flow with the flow of gas through the cathode compartments and the flow of gas through the anode compartments other that the associated anode compartments is counter to the flow of gas through the cathode compartments.
Also, disclosed are particular configurations of the reformer and fuel cell assemblies.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and aspects of the present invention will become more apparent upon reading the following detailed description in conjunction with the accompanying drawings, in which:
FIG. 1 shows an exploded view of a cross-flow fuel cell stack for an externally manifolded mixed flow field according to the present invention.
FIG. 2 shows a schematic plan view of the layout of the reforming unit used in the fuel cell stack of FIG. 1 .
FIG. 2A shows a schematic plan view of reforming catalyst loading in the reforming unit of FIG. 2 .
FIG. 3 shows the fuel flow path in the anode adjacent the reforming unit of FIG. 2 .
FIG. 4 shows the fuel gas flow path from the reforming unit to the anode adjacent thereto, and the cross-flow of fuel gas exhaust and oxidant gas with respect to successive anodes within the stack.
FIG. 5 shows an alternative flow field in which fuel gas exhaust is distributed among successive anodes in a Z-pattern in which fuel flow is initially in co-flow with the oxidant gas and thereafter in counter-flow with the oxidant gas across such anode or anodes.
FIG. 6 shows a schematic plan view of the layout of the anode plate design enabling the flow field of FIG. 5 .
DETAILED DESCRIPTION
FIG. 1 shows a fuel cell assembly 10 , including a fuel cell stack 12 comprising a plurality of cell assemblies 16 stacked one after the other in a stacking direction of the stack 12 . In the illustrative embodiment shown in FIG. 1 , the cell assemblies 16 are stacked one on top of the other so as to form the fuel cell stack 12 . The fuel cell assembly 10 also includes one or more reforming units, or reformers 30 , for internally reforming hydrocarbon fuel and for supplying reformed fuel to the fuel cells. In the illustrative embodiment shown in FIG. 1 , only one reformer 30 is shown. However, in typical fuel cell assemblies, a plurality of reformers 30 is provided at predetermined intervals throughout the stack, e.g. one reformer 30 for every 1 to 6 cell assemblies 16 , so that each reformer 30 supplies reformed fuel to its respective group of assemblies. The number of the reformers 30 provided in each stack 12 is dependent on the size of the stack 12 . As described in more detail below, the cell assemblies 16 include one or more cell assemblies 16 A, each of which is adjacent to, or associated with, a respective reforming unit 30 (hereinafter “reformer-associated assembly 16 A”), and one or more other cell assemblies 16 B not associated with a reformer 30 . It is contemplated that each reformer 30 in the assembly will service a reformer-associated cell assembly 16 A and at least five cell assemblies 16 B not associated with the reformer. The cell assemblies 16 are separated adjacent cell assemblies and/or from adjacent one or more reformers by separator plates (not shown).
As shown in FIG. 1 , each cell assembly 16 includes an electrolyte matrix 18 sandwiched between an anode electrode 20 and a cathode electrode 26 . The electrolyte matrix 18 is adapted to store an electrolyte therein, such as carbonate electrolyte, to conduct electrically charged ions between the electrodes 20 , 26 . Each assembly 16 further comprises an anode current collector 22 associated with and abutting the anode electrode 20 . In particular, in FIG. 1 , the anode electrode 20 has two opposing surfaces, wherein one of the opposing surfaces abuts, or faces, the electrolyte matrix and the other of the opposing surfaces abuts, or faces, the anode current collector 22 . The anode current collector 22 includes a plurality of corrugations 24 , which face the anode electrode 20 and which form together with the surface of the anode electrode 20 a plurality of fuel gas channels 32 through which the fuel gas passes. In certain cell assemblies 16 , a reforming catalyst is placed in the fuel gas channels 32 of all or some of the anode current collectors 22 in the fuel cell stack, so that the fuel gas is further reformed by the reforming catalyst as it passes through the gas channels 32 by direct internal reforming.
As shown in FIG. 1 , each cathode current collector 26 also has a plurality of corrugations 24 A which define, together with the associated cathode electrode 28 that abuts the cathode current collector, a plurality of oxidant gas channels 32 A through which the oxidant gas passes. Oxidant gas inlet ports 34 are formed at one end of the oxidant gas channels 32 A and are situated on a first face 1 A of the stack, and oxidant gas exhaust ports 36 , or oxidant outlet ports, are formed at the other end of the oxidant gas channels 32 A, and are situated on a second face 1 B of the stack 12 , opposing the first face 1 A. In this way, oxidant gas is supplied to each assembly 16 through the oxidant gas inlet ports 34 and carried through the oxidant gas channels 32 A for use in the respective fuel cell cathode electrode 26 . Spent oxidant gas is then outputted from each assembly 16 through the oxidant gas exhaust ports 36 .
In the anode current collectors 22 of the assemblies 16 B, other than the reformer-associated assemblies 16 A, fuel gas inlet ports 38 a are formed at one end of the fuel gas channels 32 and are situated on a third face 1 C of the stack 12 and fuel gas exhaust ports 40 , or fuel gas outlet ports, are formed at the other end of the fuel gas channels 32 on a fourth face 1 D of the stack 12 , opposing the third face 1 C. In this way, fuel is supplied to each assembly 16 B through the fuel gas inlet ports 38 a and carried through the fuel gas channels 32 for use in the respective fuel cell anode electrode 20 . Spent fuel is then outputted from each assembly 16 B through the fuel gas exhaust ports 40 .
In the fuel cell assembly 10 shown in FIG. 1 , each reformer 30 comprises a fuel inlet 42 located on the same side as the oxidant gas exhaust ports, i.e., on the second face 1 B of the stack, and an outlet 44 through which fuel gas, comprising reformed or partially reformed hydrocarbon fuel, is emitted after having been reformed in the reformer 30 . As shown, fuel is supplied to the fuel inlet 42 of each reformer 30 via a fuel supply feed 46 . An example of a fuel supply feed 46 and a reformer fuel delivery system for supplying fuel to the reformers in the stack is disclosed in U.S. Pat. No. 6,200,696, assigned to the same assignee herein and incorporated herein by reference. As shown in FIG. 1 , the fuel supply feed 46 extends along and adjacent to a side of the reformer 30 on the third stack face 1 C.
The fuel cell assembly 10 includes a plurality of manifolds enclosing second, third and fourth stack faces 1 B- 1 D. As shown, a fuel-turn manifold 48 sealingly encloses the third stack face 1 C, the fuel supply feed 46 and the adjacent side of the reformer 30 . The fuel-turn manifold 48 prevents loss of fuel during its delivery to the one or more reformers 30 and receives reformed or partially reformed fuel outputted from the one or more reformers 30 and from each reformer-associated assembly 16 A. The fuel-turn manifold 48 also directs the reformed or partially reformed fuel to the fuel gas inlet ports 38 a of the assemblies 16 B that are not adjacent to, or associated with, the reformer 30 , as described in more detail herein below. The fuel-turn manifold 48 comprises an internal feed tube and supply header (not shown) for distribution of fuel to each of the reformers 30 throughout the stack 12 . Manifolds 50 and 52 enclose second and fourth stack faces 1 B and 1 D, respectively, receive exhausted oxidant and fuel gases, respectively, leaving the stack 12 .
As can be seen in FIG. 1 , fuel enters the reformer 30 from the fuel supply feed 46 through the fuel inlet 42 , which is located on the same side of the stack 1 B as the oxidant gas exhaust ports, and flows across the reformer 30 in a counter-flow direction relative to the oxidant gas flowing through the assemblies 16 of the stack 12 . That is, the oxidant gas flows through each cell assembly 16 of the stack 12 in a first direction, shown as direction of arrow “G” in FIGS. 4 and 5 , while the fuel gas flows through the reformer 30 in a second direction, which is opposite to the first direction, shown as direction of arrows “A” in FIG. 1 . The amount of fuel flow provided to the reformer 30 from the fuel supply feed 46 is in excess of the fuel amount consumed in the electrochemical reactions of the stack so as to achieve stable operation of the stack and sufficient production of electricity by the stack. In particular, the amount of fuel provided to the reformer 30 is typically 20-30% greater than the amount consumed by the electrochemical reactions in the stack.
In certain embodiments, the fuel flowing through the reformer 30 is divided into two portions, with a first portion of the fuel flowing in the direction of the arrows “A” and a second portion being directed to the fuel-turn manifold 48 , as shown by arrow “B” in FIG. 1 . The second portion of the fuel is output from the reformer outlet 44 a located on the third side 1 C of the stack and is received by the fuel turn manifold 48 which directs the fuel to the cell assemblies 16 B which are not associated with the reformer 30 . The first portion of the fuel flows toward the reformer outlet 44 b located along the first side 1 A of the stack corresponding to the oxidant inlet side, and is output from the reformer outlet 44 b directly into an inlet port 54 of an associated or adjacent anode current collector 22 a of the reformer-associated cell assembly 16 A. The flow of the first portion of the fuel from the reformer outlet 44 b to the inlet port 54 of the associated anode current collector 22 a is shown by arrows “C” in FIG. 1 .
In certain embodiments, the reformer 30 and the reformer-associated cell assembly 16 A are separated by a separator plate, which includes one or more openings corresponding to and aligned with the reformer outlet 44 b and the inlet port 54 of the anode current collector 22 a . In addition, in some embodiments, the reformer outlet 44 b is formed as a plurality of openings in a wall of the reformer that abuts the anode current collector 22 a and the inlet port 54 is formed as a plurality of openings corresponding to the reformer outlet 44 b openings in a wall of the anode current collector 22 a that abuts the reformer 30 .
The ratio of the fuel flow amounts between the first and second portions of fuel is based on thermal management requirements of the stack 12 and also on the pressure drop across the associated anode current collector 22 a . In particular, for improved thermal management and gas mixing, it is desirable that all or substantially all of the fuel flow is directed from the reformer 30 directly to the associated anode current collector 22 a as the first portion of the fuel. However, pressure drop in the associated anode current collector 22 should be minimized in order to keep the differential pressure between the anode and the cathode sides in the reformer-associated cell assembly 16 A within 7″. As a result, if the pressure drop in the associated anode current collector 22 is too high, the amount of fuel flow as the second portion of the fuel to the fuel turn manifold 48 is increased so as to reduce the pressure drop in the associated anode current collector 22 .
As discussed in more detail herein below, reformed or partially reformed first portion of the fuel flows unobstructed through the associated anode current collector 22 a which is free of reforming catalyst or stores only a small amount of reforming catalyst therein. In addition, the associated anode current collector 22 a does not include any baffles or has only a few baffles so as to allow the fuel to flow through the current collector unobstructed. The first portion of the fuel undergoes an electrochemical reaction in the reformer-associated cell assembly 16 A and exits the associated anode current collector 22 a through an outlet port 38 into the fuel turn manifold 48 . In the fuel turn manifold 48 , the first portion of the fuel output from the outlet port 38 is mixed with the second portion of the reformed or partially reformed fuel from the reformer 30 , and is then directed by the fuel turn manifold 48 to the other cell assemblies 16 B.
The absence of reforming catalyst in the associated anode current collector 22 a or the reduced catalyst loading in the associated current collector 22 a enables endothermic cooling from the reforming reaction in the reformer 30 to be transferred to the cell assemblies 16 B not associated with the reformer, and, in particular, to the cell assemblies 16 B which are located further away from the reformer 30 and which need additional cooling. The reduced or no catalyst loading in the associated anode current collector 22 a also allows the reformer 30 to achieve a high reforming rate, without reducing direct internal reforming within the assemblies 16 B not associated with the reformer, and thus without reducing the cooling resulting from the direct internal reforming in those assemblies 16 B. Further, the absence of catalyst or reduced catalyst loading in the associated anode current collector lowers the pressure drop across the reformer-associated cell assembly 16 A and results in a decreased pressure differential between the anode and cathode sides of the assembly.
As shown in FIG. 1 , reformed or partially reformed fuel received in the fuel-turn manifold 48 , comprising a mixture of the second portion of the fuel from the reformer 30 and the first portion of the fuel partially spent in and output from the reformer-associated cell assembly 16 A, is directed to the cell assemblies 16 B not associated with the reformer. In particular, fuel from the fuel-turn manifold 48 enters the fuel inlet ports 38 a of the cell assemblies 16 B and flows through the fuel gas channels 32 of the respective cell assemblies 16 B where the fuel undergoes an electrochemical reaction in the anode electrode to produce electricity. The fuel flows through the gas channels 32 in a general direction of fuel gas exhaust ports 40 , in a cross-flow configuration with respect to the flow of oxidant flow. In particular, the flow of fuel through the anode side of each assembly 16 B is perpendicular to the flow of oxidant gas through the cathode side of the assembly 16 B. Such cross-flow configuration accomplishes uniform flow of fuel to each fuel cell and results in a low cost and simple design of the cell assembly 16 B. The cross-flow configuration of the anode side of the assembly 16 B is described in more detail below with reference to FIG. 4 . In certain embodiments, the flow of fuel through each assembly 16 B has a Z-pattern flow configuration, which is described in more detail below with reference to FIG. 5 .
As mentioned herein above, the fuel flowing through the gas channels 32 of the cell assemblies 16 B is also directly internally reformed by the reforming catalyst stored in the channels 32 . The direct internal reforming of fuel within each assembly 16 B produces cooling within the assembly 16 B. As described in more detail below, the reforming catalyst may be loaded within the channels 32 at varying loading densities so as to achieve greater or smaller amounts of cooling in predetermined areas of the respective assembly 16 B and to accomplish a desired thermal profile of the stack.
As shown in FIG. 1 , spent fuel, after undergoing the electrochemical reaction in the anode of the cell assembly 16 B, is output from the fuel gas exhaust ports 40 of the anode current collector 22 into the anode exhaust stack manifold 52 . Spent fuel received in the stack manifold 52 may then be exhausted out of the fuel cell assembly 10 . In certain embodiments, all or a portion of the spent fuel may be recycled for further use in the fuel cell assembly 10 . Also, in some embodiments, spent fuel may be further processed so as to extract water therefrom for humidifying fuel input into the assembly, before recycling the remaining spent fuel to the assembly 10 or exhausting it from the assembly 10 .
An illustrative configuration of a reformer 30 that can be used in the fuel cell assembly 10 of FIG. 1 is shown in more detail in FIG. 2 . The reformer 30 shown is rectangular in shape and has dimensions corresponding to the dimensions of the fuel cell stack's 12 cross-section. The corners of the reformer are labeled A through D and correspond to the respective corners of the fuel cell stack 12 . Corner A of the reformer is adjacent the fuel inlet of the reformer and corresponds to the corner of the fuel cell stack that is adjacent the fuel inlet and oxidant outlet faces. Corner B of the reformer is adjacent the fuel gas outlet of the reformer and corresponds to the corner of the fuel cell stack 12 which is adjacent the fuel inlet and oxidant inlet faces of the stack 12 . Corner C of the reformer is also adjacent the fuel gas outlet of the reformer and corresponds to the stack corner which is adjacent the fuel outlet and oxidant inlet faces of the stack 12 , while corner D of the reformer corresponds to the fuel cell stack corner adjacent the oxidant outlet face and fuel outlet faces of the stack. The reformer sidewall extending between corners A and B of the reformer faces the third face 1 C of the stack 12 and is enclosed by the fuel-turn manifold 48 . Reformer sidewall extending between corners B and C faces the first stack face 1 A corresponding to the oxidant inlet side of the stack, while reformer sidewall extending between corners C and D faces the fourth stack face 1 D and is enclosed by the manifold 52 . Finally, reformer sidewall that extends between corners D and A of the reformer faces the second stack face 1 B, corresponding to the oxidant outlet face of the stack, and is enclosed by the manifold 50 .
Referring to FIG. 2 , the reformer 30 comprises a plurality of sections, including a fuel inlet section, labeled as Section A, and reforming sections, labeled as Section B and Section C. As discussed in more detail below, a plurality of baffles, labeled as Baffle 1-6, are provided in the reformer to define the Sections A-C and to guide the fuel through these sections to achieve a desired fuel flow and distribution through the reformer.
As shown in FIG. 2 , fuel gas enters the reformer 30 through the fuel gas inlet 42 and flows along the inlet Section A so as to be laterally distributed along Section A. From Section A, the fuel flows into and through Section B, which includes a plurality of zones 1-4. The first zone of Section B, labeled as “Zone 1,” is located furthest away from the reformer inlet 42 , while the fourth zone of Section B, labeled as “Zone 4,” is located adjacent to the reformer inlet 42 . The second and third zones of Section B, labeled as “Zone 2” and “Zone 3,” are located in the central portion of Section B, between the first and fourth zones.
As shown in FIG. 2 , a plurality of baffles 1-3 are provided to separate the inlet Section A from the reforming Section B of the reformer and to guide the flow of fuel from the inlet Section A to the four zones of Section B. In particular, Baffle 1 is provided at the inlet of the fourth zone, Zone 4, to achieve a desired flow restriction of the fuel from the inlet Section A to the fourth Zone 4. Similarly, Baffle 2 is provided at the inlet of the third zone, Zone 3, and Baffle 3 is provided at the inlet of the second zone, Zone 2, to restrict the flow of fuel from the inlet Section A to the third and second zones, respectively. Baffles 1-3 also ensure that the fuel flowing through the inlet Section A is distributed throughout the inlet section and into each of the zones of the reforming Section B. In particular, Baffles 1-3 are calibrated to have flow resistances from Section A to each zone in Section B so as to achieve a desired flow distribution of fuel through each zone of Section B. In addition, as shown in FIG. 2 , zone 1 is free of baffling to ensure that the flow of fuel through the reformer 30 is constant, particularly if Baffles 1-3 are non-optimized.
As also shown in FIG. 2 , Baffles 4-6 are provided in the reformer 30 to separate the respective zones of Section B and to straighten and guide the flow of fuel through each zone of Section B. In particular, Baffle 4 is provided between Zone 4 and Zone 3, Baffle 5 is provided between Zone 3 and Zone 2, and Baffle 6 is provided between Zone 2 and Zone 1. In certain embodiments, Baffles 4-6 may extend into Section C of the reformer so as to further guide the flow of fuel to achieve a desired fuel flow through the reformer.
The Baffles 1-6 used in the reformer may have various constructions. In certain embodiments some or all of the baffles are formed from one or more of: rods inserted into the corrugations of the reformer 30 , porous structured materials inserted into or between the corrugations of the reformer 30 or sheet metal folded at the edge to form mechanical baffles. The materials from which the baffles 1-6 are formed have be able to withstand the high temperatures in the fuel cell stack. For example, ceramic rope is a suitable porous structured material for forming one or more of Baffles 1-6.
In addition, the configuration and arrangement of the baffles in the reformer is not limited to the one shown in FIG. 2 . In particular, since the optimum thermal management in the fuel cell stack 12 is best achieved by routing substantially all of fuel gas flow from the reformer 30 to the reformer-associated cell assembly 16 A, the configuration of the baffles may be varied to achieve such routing.
As shown in FIG. 2 and as mentioned herein above, the reformer includes an outlet 44 b through which fuel gas flows to the associated or adjacent anode 20 and current collector 22 of a reformer-associated cell assembly 16 B. The outlet 44 b is formed in the top portion of the enclosure of the reformer that abuts the associated current collector 22 . In the embodiment shown in FIG. 2 , the outlet 44 b is L-shaped and extends along, or adjacent to, the wall of the reformer between corners B and C and partially along, or adjacent to, the wall between corners C and D of the reformer. In particular, the reformer outlet 44 b extends from corner C in the direction of corner D over end portions of Sections C and B of the reformer, without reaching the inlet Section A of the reformer. In other embodiments, the reformer outlet 44 b extends only between corners B and C of the reformer or only between corners C and D of the reformer.
In the illustrative embodiment shown in FIG. 2 , the reformer also includes a second outlet 44 a , which outputs the second portion of the fuel into the fuel-turn manifold 48 . As discussed above with respect to FIG. 1 , the second portion of the reformed or partially reformed fuel is output from the reformer's second outlet 44 a into the fuel-turn manifold 48 and thereafter supplied to the cell assemblies 16 B not associated with the reformer. The first portion of the reformed or partially reformed fuel is output from the reformer's outlet 44 b to the anode current collector 22 of the reformer-associated cell assembly 16 A. However, in other embodiments, all of the fuel flowing through the reformer 30 is outputted to the reformer-associated cell assembly 16 A through the outlet 44 b , and in such other embodiments, the reformer 30 does not include the second outlet 44 a shown in FIG. 2 .
The reformer 30 shown in FIG. 2 includes reforming catalyst disposed in the corrugations of the reformer to promote the reforming of the fuel. The loading density of the reforming catalyst in the reformer, and in particular in the different Zones and Sections of the reformer, may be varied for improved thermal management in the stack and to achieve the desired temperature distributions in the reformer. In particular, greater loading density of the reforming catalyst can be provided in the areas of the reformer where additional cooling is required, and smaller loading density of the reforming catalyst is provided in areas of the reformer which do not require as much cooling. In addition, gradual loading density variations are preferred so as to obtain smooth thermal transitions in the reformer. FIG. 2A shows an illustrative catalyst loading configuration which can be used in the reformer 30 of FIG. 2 .
As shown in FIG. 2A , the reforming catalyst loading densities are varied not only between the different sections of the reformer, but also within each section of the reformer. The loading density of the reforming catalyst disposed in the inlet section A of the reformer is lower than the loading density in the other sections. As shown, the initial catalyst loading density in the inlet section A of the reformer near the inlet 42 is 1/64, i.e. 1 catalyst unit or pellet for every 64 corrugations. The loading density in the inlet section then increases to 1/48 and thereafter to 1/16 as the fuel travels along the length of the inlet section A.
In the illustrative embodiment shown in FIG. 2A , the catalyst loading density in Section B of the reformer, and in particular, in each of the Zones 1-4 is greater than the catalyst loading density in the inlet section A. In addition, the catalyst loading density in Zone 1 is greater than the catalyst loading in Zones 1-4, the catalyst loading density in Zone 2 is smaller than in Zone 1 but greater than in Zones 3-4, and the catalyst loading density in Zones 3 and 4 is smaller than in Zones 1 and 2.
In particular, the catalyst loading density in Zone 1 is 1/12, i.e. 1 catalyst unit or pellet for every 12 corrugations, in an area adjacent to the inlet section A and to the outlet 56 of the reformer, and thereafter gradually increases to 1/5 loading density. A portion of Zone 1 that extends from the inlet section A to Section C of the reformer and which is adjacent to Zone 2 has increased catalyst loading at 1/2 loading density.
The catalyst loading density in Zone 2 is 1/48, i.e. 1 catalyst unit or pellet for every 48 corrugations, in an area adjacent to the inlet section A and to Zone 1 of the reformer, and thereafter gradually increases to 1/8 loading density and to 1/2 loading density in the direction from the inlet section A to Section C of the reformer. Additionally, a portion of Zone 2 which extends from the inlet section A to Section C of the reformer and which is adjacent to Zone 3 has an increased catalyst loading density of 1/2.
The catalyst loading density in Zone 3 is 1/48 in an area of Zone 3 adjacent to the inlet section A and to Zone 2 of the reformer, and thereafter gradually increases to 1/16 loading density and 1/2 loading density in the direction from the inlet section A to Section C of the reformer. In addition, a portion of Zone 3 which extends from the inlet section A to Section C of the reformer and which is adjacent to Zone 4 has an increased catalyst loading density of 1/2. Similarly, the catalyst loading density in the area of Zone 4 that is adjacent to the inlet section A and to Zone 3 of the reformer is 1/48, and thereafter increases to 1/16 and to 1/2 loading density in the direction from Section A to Section C of the reformer.
In the outlet Section C of the reformer, the catalyst loading density is 1/2 in the area adjacent to Zone 4 and a portion of Zone 3 of the reformer, thereafter gradually decreasing to a loading density of 1/3 in the area adjacent to a portion of Zone 3 and a portion of Zone 2, and to a loading density of 1/16 in the area adjacent to a portion of Zone 2 and a portion of Zone 1. The catalyst loading density is gradually reduced to 0 in the outlet area near corner C of the stack.
The catalyst loading configuration shown in FIG. 2A achieves a temperature distribution which provides more cooling in the central area of the reformer as well as in the area of the reformer near the fuel outlet side of the stack. The configuration of FIG. 2A also reduces temperature gradients in the reformer-associated cell assembly 16 A. It is understood, however, that the catalyst loading configuration shown in FIG. 2A is illustrative and can be modified depending on the configuration of the fuel cell stack and so as to achieve other temperature distributions to provide more cooling to other areas of the stack.
Referring now back to FIG. 1 , fuel gas leaving the reformer 30 through the outlet 44 b enters the inlet 54 of the associated current collector 22 of the reformer-associated cell assembly 16 A. In the associated current collector, fuel flow has a co-flow configuration relative to the oxidant gas flow, i.e. parallel to the oxidant gas flow, in certain areas of the associated anode current collector, and a cross-flow configuration relative to the oxidant gas flow, i.e. perpendicular to the oxidant gas flow, in other areas of the associated anode current collector. The co-flow configuration of the fuel flow in the anode current collector is shown by arrows “D” in FIG. 1 , while the cross-flow configuration of the fuel flow in the anode current collector is shown by arrows “E” in FIG. 1 .
FIG. 3 shows in more detail the anode current collector 22 of the reformer-associated cell assembly 16 A of FIG. 1 and the flow path of fuel gas through the current collector 22 . As shown, the anode current collector 22 includes an inlet 54 , the relative location and shape of which corresponds to the location and shape of the outlet 44 b of the reformer. The fuel flows through the channels 32 in the anode current collector 22 and the direction of the fuel flow through the current collector 22 is illustrated by arrows “E”, which include portions “e 1 ” and “e 2 ”. Portions “e 1 ” of the arrows “E” represent the flow of fuel which is substantially parallel to the flow of oxidant gas through the fuel cell stack, i.e. having a co-flow configuration. Portions “e 2 ” of the arrows “E” represent the direction of the flow of fuel which is perpendicular to the flow of oxidant gas through the fuel cell stack, i.e. having a cross-flow configuration.
As shown, the flow of fuel through the anode current collector of the reformer-associated assembly 16 A starts in the same direction as the flow of oxidant gas through the stack, and then changes direction so that the fuel flows in a direction that is perpendicular to the flow of oxidant gas toward the outlet of the anode current collector 38 . Fuel gas exits the channels 32 of the anode current collector substantially uninhibited through the outlet 38 , shown by the arrows “E” and is outputted into the fuel-turn manifold 48 .
Fuel gas is not completely reacted during the electrochemical reaction in the associated or adjacent anode 20 of the reformer-associated assembly. Fuel gas exhaust leaving the anode current collector 22 of the reformer-associated assembly 16 A and collected in the fuel-turn manifold 48 is then distributed to the other cell assemblies 16 B not associated with the reformer. In this way, unreacted fuel in the fuel gas exhaust of the reformer-associated assembly 16 A is electrochemically reacted in the other cell assemblies 16 B to produce electricity.
As discussed herein above with respect to FIG. 1 , in certain embodiments, the flow of fuel through the anode side of the cell assemblies 16 B not associated with the reformer 30 has a cross-flow configuration relative to the flow of oxidant fuel through these assemblies. FIG. 4 shows the flow of fuel in such embodiments, including the flow of fuel through the reformer 30 , through the fuel cell 58 of the reformer-associated assembly 16 A and through the next cell assembly 16 B not associated with the reformer. The flow of fuel through the next cell assembly 16 B is exemplary of the flow of fuel through the other cell assemblies in series with cell 58 .
As shown in FIGS. 1 and 4 , the flow of fuel gas through the reformer 30 is labeled by the arrow “A” and the continued flow of fuel from the reformer 30 to the fuel gas inlet 54 of the reformer-associated cell assembly 16 A is labeled by the arrow “C.” As also shown, the flow of fuel passing through the anode 20 and anode current collector 22 of the reformer-associated cell assembly 16 A is indicated by arrows “E”, which show the fuel flowing first in a co-flow configuration with respect to the oxidant gas and thereafter changing to the cross-flow configuration relative to the flow of oxidant gas. The co-flow and cross-flow configuration of the fuel flow through the reformer-associated assembly 16 A is shown by the relationship between arrows “E” and “G”, wherein the arrow “G” represents the direction of the oxidant flow. As discussed above, fuel leaving the reformer-associated assembly 16 A is outputted to the fuel-turn manifold 48 , which directs the fuel to the fuel inlets of the other assemblies 16 B not associated with the reformer 30 .
The direction of the flow of fuel from the fuel-turn manifold 48 through the anode side of the successive assemblies 16 B not associated with the reformer is shown by arrows “H” in FIG. 4 . As can be seen in FIG. 4 , the fuel gas flows through the anodes and anode current collectors of the successive assemblies 16 B in a cross-flow configuration relative to the direction of the flow of oxidant gas. This cross-flow configuration is demonstrated by the arrows “H” and “G” which show the flow of fuel and oxidant, respectively, through the assembly. The cross-flow arrangement of the flow fields through the assemblies 16 of the stack as shown in FIG. 4 ensures uniform distribution of the fuel to the successive cell assemblies 16 B in the stack 12 , while maintaining low cost and simple design of the stack.
As discussed above, in certain embodiments, the cell assemblies 16 B not associated with the reformer have a Z-pattern flow configuration for the flow of fuel through the anode side is the assemblies 16 B. FIG. 5 shows the flow of fuel in such embodiments, including the flow of fuel through the reformer 30 , through the fuel cell 58 of the reformer-associated assembly 16 A and through the next cell assembly 16 B not associated with the reformer. The flow of fuel through the next cell assembly 16 B is exemplary of the flow of fuel through the other cell assemblies in series with cell 58 .
As shown in FIG. 5 , the flow of fuel through the reformer 30 and through the fuel cell 58 of the reformer-associated cell assembly 16 A is the same, or substantially the same, as the flow of fuel through the reformer and the reformer-associated cell assembly of FIG. 4 . As in FIG. 4 , the fuel leaving the reformer-associated cell assembly 16 A is outputted to the fuel-turn manifold 48 which directs the fuel to the next or successive cell assemblies 16 B not associated with the reformer.
In FIG. 5 , the Z-pattern flow path of fuel through the anode 20 and anode current collector 22 of the successive cell assemblies 16 B is shown by arrows “I” and “J.” As shown, the arrow “I” shows the direction of the fuel flow in a counter-flow configuration relative to the oxidant gas flow, labeled by arrow “G,” while the arrow “J” shows the direction of fuel flow in a cross-flow configuration relative to the flow of oxidant gas. In the Z-pattern flow configuration shown in FIG. 5 , the fuel flow path combines the counter-flow direction of the fuel flow and the cross-flow direction of the fuel flow relative to the direction of the oxidant gas flow, so that the fuel flowing through each of the successive assemblies 16 B flows in a direction counter to the direction of oxidant flow over a portion of its path and in a direction substantially perpendicular to the direction of the oxidant flow over the other portion of its flow path. As shown in FIG. 5 , some of the fuel flowing the assembly 16 B first has a counter-flow configuration and thereafter has a cross-flow configuration relative to the oxidant gas flow, while another portion of the fuel flowing through the assembly has a cross-flow configuration followed by the counter-flow configuration.
The Z-pattern flow path configuration of the fuel is achieved by blocking a portion of the fuel gas inlet port 38 of the anode current collector 22 so as to impede the flow of fuel through the blocked portion of the fuel gas inlet port 38 a and to direct the fuel to enter the anode current collector 22 only through the open or unblocked portion of the fuel gas inlet port 38 a . As shown in FIG. 5 , the blocked portion of the fuel gas inlet port 38 a starts from a corner of the anode current collector 22 adjacent to the oxidant gas inlet ports 34 and the first face of the stack 1 A and extends along the portion of the fuel gas inlet port 38 a in a direction of the other corner of the anode current collector 22 adjacent to the oxidant gas outlet ports 36 and the second stack face 1 B. In this way, an open fuel inlet portion is formed in the anode current collector 22 which is near the oxidant gas outlet ports 36 of the stack 12 , so that fuel is directed to enter the anode current collector 22 adjacent to the oxidant outlet face 1 B of the stack 12 .
As shown, a portion of the fuel outlet port 40 of each assembly 16 B can also be blocked off so as to direct the fuel leaving the anode current collector 22 through the open, or unblocked, portion of the outlet port 40 . In particular, the blocked off portion of the fuel outlet port 40 extends from a corner of the anode current collector 22 adjacent to the oxidant gas outlet ports 36 and the second stack face 1 B in a direction of the other corner of the anode current collector 22 adjacent to the oxidant gas inlet ports 34 and the first stack face 1 A. The open or unblocked portion of the fuel outlet port 40 is located adjacent to the first face of the stack 1 A and the oxidant inlet ports 34 .
The blocked off portions of the fuel inlet port and the fuel outlet port are formed by using baffles, wall extensions or any other suitable means for impeding the flow of fuel through the inlet and outlet ports. The blocking of the portions of the fuel inlet and the fuel outlet ports as described above directs the fuel to enter the anode current collector 22 of each assembly 16 B adjacent to, or near, the face of the stack 1 B associated with the oxidant outlet ports 36 , to flow through the anode side of the assembly 16 B in a Z-shaped path and to exit the anode current collector 22 adjacent to, or near, the face of the stack 1 A associated with the oxidant inlet ports 34 . This configuration of the anode current collector 22 combines the cross-flow and counter-flow configurations of the fuel relative to the oxidant gas flow since the fuel is directed to flow in a direction perpendicular to the flow of oxidant gas and also in a direction opposite to that of the flow of oxidant gas in order to get from the open portion of the fuel inlet port 38 to the open portion of the fuel outlet port 40 .
In addition, one or more baffles may be used in the anode current collector to direct the flow of fuel in the Z-pattern flow path, and/or the direction of the corrugations in the anode current collector 22 of each assembly 16 B may be configured so as to direct the flow of fuel through the anode current collector in a Z-shaped path. One or more baffles may also be used to control the fuel flow distribution through the anode current collector so as to achieve fuel flow uniformity throughout the anode current collector. In certain embodiments, the baffles and/or the configured direction of the corrugations are used together with the blocked off fuel inlet and outlet port portions to promote the flow of fuel in a Z-shaped path. In other embodiments, the baffles and/or the configured direction of the corrugations may be used without blocking off portions of the fuel inlet and outlet portions to achieve the Z-pattern flow path.
As shown in FIGS. 1 and 5 , the Z-pattern flow path configuration through the anode side of the cell assemblies 16 B realizes the counter-flow configuration of the fuel relative to the oxidant fuel without requiring separate fuel and oxidant gas manifolds to be present on the same sides of the stack. The Z-pattern flow path configuration also results in a substantially lower differentials in pressure gradients along the anode flow channels, and in an improved uniformity of current density throughout the stack 12 . As a result, greater efficiency in the production of electricity and extended service life of the stack 12 can be achieved.
Although the Z-pattern flow path configuration shown in FIG. 5 combines the combination of the cross-flow and counter-flow configurations of the fuel flow relative to the oxidant gas flow, it is understood that the Z-pattern flow configuration may be modified so as to combine the cross-flow and co-flow configurations of the fuel flow relative to the oxidant flow. Such modified Z-pattern flow configuration can be achieved by blocking off a portion of the anode current collector inlet from a corner of the anode current collector adjacent the oxidant gas outlet ports and the second face of the stack and by blocking off a portion of the anode current collector outlet from a corner of the anode current collector adjacent the oxidant gas inlet ports and the first face of the stack. In this way, fuel is allowed to enter the anode side of the cell assembly through the unblocked portion of the anode current collector inlet adjacent to the oxidant gas inlet ports and to flow through the anode side so as to exit through the unblocked portion of the anode current collector outlet adjacent to the oxidant gas outlet ports.
FIG. 6 shows an illustrative construction of an anode current collector of one of the cell assemblies 16 B not associated with a reformer, wherein the anode current collector enables the Z-pattern flow configuration discussed above. As shown, the anode current collector includes an inlet 60 through which fuel enters the anode current collector, an inlet section 62 of the current collector, an outlet section 72 of the current collector, a central area divided into a plurality of zones, i.e. zones 1-4, and a plurality of baffles for directing the flow of fuel through the anode current collector.
In particular, the inlet 60 of the anode is formed as an unblocked portion of the inlet side of the anode current collector and extends from the corner of the anode current collector adjacent to the oxidant gas outlet ports of the stack. Fuel enters the anode current collector through the inlet 60 in cross-flow configuration relative to the oxidant gas. In the anode current collector, the fuel is first distributed over the inlet section 62 of the anode current collector which extends from the inlet 60 along the length of the side of the current collector adjacent to, or aligned with, the oxidant outlet ports.
As shown in FIG. 6 , the plurality of baffles 64 , 66 , 68 and 70 are disposed in the anode current collector for directing the fuel flow from the inlet section 62 to the respective zones of the central section of the anode current collector. In particular, baffles 64 , 66 and 70 are disposed between the inlet section 62 and Zone 4, Zone 3 and Zone 1, respectively. These baffles 64 , 66 and 70 provide flow resistance to limit the amount of fuel flowing into each of Zone 4, Zone 3 and Zone 1, respectively, so that the fuel is distributed between the Zones 1-4. The flow resistance of each baffle 64 , 66 and 70 may be adjusted so as to allow greater or smaller amount of fuel flow from the inlet section to the Zone corresponding to the baffle. In the illustrative embodiment of FIG. 6 , no baffle is provided between the inlet section 62 and Zone 2 so that the fuel flow from the inlet section 62 into Zone 2 is unobstructed. In addition, baffle 68 extends between Zone 2 and Zone 3 for directing the flow of fuel along Zone 2 and along Zone 3 and preventing the mixing of fuel between Zones 2 and 3.
The combination of baffles 64 , 66 , 68 and 70 as shown in FIG. 6 results in a Z-pattern flow configuration of the fuel flow through the anode side of the cell assembly 16 B. In particular, the flow of fuel along the inlet section 62 and the outlet section 72 of the anode current collector has a cross-flow configuration relative to the oxidant gas flow, while the flow of fuel along Zones 1-4 of the central section of the anode current collector has a counter-flow configuration relative to the oxidant gas flow. It is understood that in other illustrative embodiments, the baffles 64 , 66 , 68 and 70 may be arranged so that the fuel flow along Zones 1-4 of the central section of the anode current collector has a co-flow configuration relative to the oxidant gas flow.
In the embodiment shown in FIG. 6 , the loading of the reforming catalyst in the anode current collector is varied so as to provide a desired flow resistance and a desired amount of reforming in each section of the anode current collector. In particular, the inlet section 62 of the anode current collector has low or no reforming catalyst disposed therein so as to minimize fuel flow resistance. In each of Zones 1-4, catalyst loading density is increased relative to the catalyst loading density in the inlet section 62 so as to increase flow resistance in Zones 1-4 and to achieve flow uniformity through the Zones 1-4. The greater catalyst loading density in Zones 1-4 lowers the gas flow velocity due to the increased flow resistance, and optimizes the electrochemical reaction needed to produce electricity. As a result, most of the direct internal reforming occurs in Zones 1-4 of the central section. As discussed herein below, the reforming catalyst loading density in each of Zones 1-4 may be varied from one Zone to another and throughout each zone. For example, the overall catalyst loading density in one of the Zones may be greater than the catalyst loading density in another zone so as to provide more reforming, and thus more cooling, in the zone with greater catalyst loading density. In addition, the density of the reforming catalyst loading can be varied along each Zone 1-4 so that the catalyst loading density is greatest in the areas of the cell assembly where the most cooling is required.
The configuration of the anode current collector shown in FIG. 6 is compatible with the structure and design of conventional carbonate fuel cell stacks. In particular, in conventional carbonate fuel cell systems, boundary regions, also called wet-seal regions, of each cell assembly are inactive where no electrochemical reaction occurs. U.S. patent application Ser. No. 12/016,564, which is incorporated herein by reference, discloses an example of such fuel cell design, particularly a fuel cell employing a bipolar separator plate that forms the wet seal regions of the fuel cell. The inlet and outlet sections of the anode current collector shown in FIG. 6 , which are used for distributing fuel throughout the central section of the current collector and for collecting spent fuel gas from the central section, are disposed within the anode side wet seal regions of the cell assembly. By using the inactive wet seal regions for distributing and collecting fuel, the amount of reforming and the location of the central region of the anode current collector where the reforming occurs can be optimized for improved operation of the fuel cell assembly. In addition, pressure drop in the inlet section of the anode current collector is decreased, thus improving the uniformity in the flow of fuel through the central region of the anode current collector.
As described herein above, the assembly includes a two-stage supply of fuel to the fuel cell stack 12 , wherein the first stage comprises fuel supply from one or more reformers 30 to a respective reformer-associated cell assembly 58 , and the second stage comprises distribution of partially-reformed fuel from the fuel-turn manifold 48 to each of the remaining fuel cells of the stack 12 . When compared to prior stack designs, the stack shown in FIG. 1 requires lower fuel flow for powering the stack 12 because the fuel from the first stage is recycled during the second stage. In addition, since the second stage receives and uses partially spent fuel from the first stage, the total amount of fuel flow to the stack may be reduced as compared to the total amount of fuel flow received in conventional stacks. As a result, high fuel utilization, i.e., high efficiency in the production of electricity, by the stack 12 is achieved by the two-stage configuration of the invention.
In addition to the two-stage fuel supply described above, the stack 12 shown in FIG. 1 has improved thermal management, which increases the stack's service and operating life. The flow path of the fuel through the reformer 30 , as described above, contributes to such improved thermal management by optimizing the endothermic reaction occurring in the reformer 30 .
Also, the absence of catalyst or the reduced catalyst loading in reformer-associated cell assemblies 16 A contributes to more stable stack temperature gradients compared to conventional stacks since fuel gas supplied thereto is reformed to a larger extent in the reformer 30 . In particular, since there is no, or a very small amount of, reforming catalyst in the reformer-associated cell assembly 16 A, a larger fraction of the endothermic reforming reaction can be produced by the reformer. Thus, the efficiency of the reformer and of the reforming reaction rate in the reformer are improved. This is particularly important to the performance and service life of the stack because the reforming catalyst in the reformer is not exposed to carbonate electrolyte and is therefore more likely to have stable activity as the stack ages. The improved reforming efficiency in the reformer therefore improves the thermal stability of the stack.
Also, the two-stage fuel supply in the assembly minimizes the volatility in temperature gradients that result from catalyst deactivation in the cell assemblies 16 B not associated with the reformer 30 and improves uniformity in the reforming reaction in the reformer. The cell assemblies 16 B not associated with the reformer also benefit from the cooling that results from the cooled fuel gas exhaust supplied from the reformer-associated cell assembly 16 A to the fuel-turn manifold 48 and from the endothermic direct internal reforming reaction within each of the cell assemblies 16 B. In particular, the higher reforming and thus higher cooling rate in the cell assemblies 16 B not associated with the reformer reduces the peak current density within the cell assemblies and makes the current density distribution in the stack more uniform. Uniform current density reduces local high temperatures and results in an enhanced control of temperature gradients from one cell assembly 16 B to another. Greater thermal stability and reduced temperature gradients in the stack result in reduced thermal stresses on the components of the stack and in decreased contact losses between the components of the cell assemblies.
Further, the fuel flow field in the reformer-associated cell assembly 16 A causes a shift in current density distribution in the stack which results in an increased temperatures at the oxidant inlet and fuel outlet regions of the stack. The increased temperatures at the oxidant inlet and fuel outlet regions, in turn, increase the reforming activity of the catalyst disposed in the other cell assemblies 16 B not associated with the reformer so as to provide adequate methane conversion. In addition, the shift in the current density in the fuel cell stack of FIG. 1 and the two-stage fuel delivery described above counteract the tendency to concentrate current density near the anode inlet region of the stack, which is often experienced by conventional stacks with cross-flow configuration. This, in turn, minimizes temperature shifts in the stack, particularly if the fuel utilization rate is increased, thus leading to higher operating efficiency of the stack. Furthermore, since the reformer inlet section is located near the oxidant outlet side of the neighboring cell assemblies, cooling is provided to the oxidant outlet gas, thus reducing thermal management requirements of the stack. For these reasons, the efficiency in the production of electricity by the stack and the service life of the stack are increased.
In all cases it is understood that the above-described arrangements are merely illustrative of the many possible specific embodiments which represent applications of the present invention. Numerous and varied other arrangements can be readily devised in accordance with the principles of the present invention without departing from the spirit and scope of the present invention. For example, it is within the contemplation of the present invention to further provide thermal management for the stack by providing additional external means to modulate the fuel temperature even prior to entering the stack.
INCORPORATION BY REFERENCE
The following patents and published patent applications, assigned to the same assignee herein, are incorporated herein by reference:
U.S. Pat. No. 6,200,696 U.S. Pat. No. 5,175,062 U.S. Application Publication No. 2006/0123705 U.S. Application Publication No. 2004/0071617
|
A fuel cell assembly including a fuel reforming unit for reforming a fuel supply for a series of fuel cells constituting a fuel cell stack. The reformed fuel supply is routed first to the anode of the fuel cell most adjacent the reforming unit, and thereafter to a manifold external to the stack. The manifold intakes that portion of the reformed fuel supply not fully exhausted after passing through the first anode and feeds such reformed fuel to successive fuel cells in series, thus providing staged fuel supply throughout the stack and optimal fuel utilization in producing electricity. The reforming unit includes a series of baffles for directing the reformed fuel supply to the first anode and to the manifold to maximize utilization of fuel consumed by cells in the stack. Also, cooling occurring as a result of the endothermic reaction occurring in the reforming unit is captured and spread optimally throughout the stack to achieve optimal temperature gradients throughout the stack, thus enabling optimal operation of and increased life of the stack.
| 8
|
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of applicant's patent application, Ser. No. 07/921,314, filed Jul. 28, 1992, U.S. Pat. No. 5,394,658, issue date Mar. 7, 1995, entitled FREE STANDING MODULAR FURNITURE AND WALL SYSTEM, which is a continuation of Ser. No. 07/787,678, filed Nov. 4, 1991, now abandoned, which is a continuation of Ser. No. 07/226,443, filed Jul. 29, 1988, now abandoned.
BACKGROUND OF THE INVENTION
Open office panel systems, commercialized heavily for the past twenty years, have a number of drawbacks. While they have been promoted as being versatile, movable systems that permit easy office re-arrangement, this has not proven to be the case. A complete partition or panel system involves numerous parts, and a completely assembled systems, have so many inter-dependent components and complicated fasteners that it is a difficult task, requiring special skills, in order to make adjustments in an open plan layout after the system has been installed. The complexities of the systems and number of parts involved make initial installation complex, and modification of an existing system involves similar difficulties.
Open office panel systems also have functional drawbacks. Such panels typically are thin and flimsy. Moreover, such panels were originally developed prior to the availability of personal computers and heavy use of power and communications wiring for desk top and work station applications. Attempts have been made to accommodate electrical and electronic wiring in open office panel systems, but these attempts have met with limited success with wiring still being difficult, generally inadequate, or at least aesthetically unappealing, for the modern electronic office environment.
Open office panel systems generally provide load bearing walls, with desk tops, shelving, and storage units necessarily being mounted on the panels themselves. This requires that the panels be structurally capable of supporting such loads and it necessarily limits the variation of office furniture available to individual office workers to a limited range of wall hung furniture.
The concept and appearance of open panel systems also has produced some user dissatisfactions based on emotional considerations. The thin walls, open doorways and general sameness of appearance tends to create a feeling of monotony and produces a maze-like appearance in an office environment. Office workers get the feeling that they are in temporary quarters with little privacy or individuality or importance.
As a result of the obsolescence and growing dissatisfaction with conventional open plan partition systems, there has been renewed interest in traditional office desks and office furniture, notwithstanding the limitations in such systems that caused the development of the open office partition systems in the first place.
It is an object of the present invention to provide an improved free standing office furniture and wall system that possesses the desirable features of both free standing desks and panel systems while substantially overcoming the limitations in both systems.
SUMMARY OF THE INVENTION
In accordance with the present invention, an improved free standing modular furniture and wall system comprises a series of compatible components including a free standing post and beam or archistructure system, a compatible free standing, non-load bearing wall system, and a compatible series of free standing desks and screens. All of the components are modular in nature, with a limited number of separate components providing an extremely wide array of office environment choices. All of the components are integrally designed for almost unlimited flexibility in layout and arrangement and re-arrangement of the office environment, maximum individual identity of the offices, aisleways, and common areas, and an almost unlimited ability to easily and invisibly bring safe electrical and electronic wiring to the individual work stations and to change such wiring at will without structural modifications or tools.
These and other features of the present invention are described in detail in connection with preferred embodiments of the invention, which are described in detail below and shown in the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an office layout employing the furniture system of the present invention.
FIG. 2 is a perspective view of a pocket door of the present invention.
FIG. 3 is a perspective view of a sliding full door and a sliding half door or window of the present invention.
FIG. 4 is a perspective, exploded view showing various components of the post and beam construction of the present invention.
FIG. 5 is a perspective, exploded view showing a wall section and wall post support.
FIG. 6 is a perspective view showing a short post and beam construction forming a railing and a post construction with light fixture.
FIG. 7 is an exploded, perspective view showing the manner in which a beam is connected to a post.
FIG. 8 is an exploded, perspective view similar to FIG. 7 showing the electrical connections extending from the ceiling and from the floor through the post and into the beam.
FIG. 9 is a perspective view showing typical electrical connections in the beam construction.
FIG. 10 is a cross-sectional view of the beam of the present invention.
FIG. 11 is a cross-sectional view of the beam showing signage attached to the beam.
FIG. 12 is a cross-sectional view of the beam showing the attachment of a sliding door to the beam.
FIG. 13 is a cross-sectional view of the beam showing ceiling lighting incorporated into the beam.
FIG. 14 is a cross-sectional view of the beam showing the incorporation of lighting in the underside of the beam.
FIG. 15 is a perspective view showing a typical free standing wall construction in accordance with the present invention.
FIG. 16 is a pictorial perspective view showing the removal of a wall cover from the side of one wall section.
FIG. 17 is a perspective view showing four interconnected wall sections with the wall covers removed.
FIG. 18 is an exploded, perspective view showing a pair of wall sections connected at right angles by a wall connector.
FIG. 19 is a cross-sectional view showing the manner in which a top cap is mounted on the wall panel of the present invention.
FIG. 20 is a cross-sectional view showing a wall panel of the present invention with a wall top mounted on the wall panel.
FIG. 21 is a broken cross-sectional view showing the power routing and access means at the bottom of the wall panel.
FIG. 22 is a perspective view showing a wall panel with an electrical outlet mounted on the bottom thereof.
FIG. 23 is a perspective view showing the frame and electrical power fixtures of the wall panel.
FIG. 24 is a perspective view showing the frame and power fixtures of the present invention mounted with an under carpet flat power cable.
FIG. 25 is a perspective view similar to FIG. 24 showing a floor power monument.
FIG. 26 is a perspective view similar to FIG. 25 showing a flat wire cable hookup to the communication wiring in the panel system.
FIG. 27 is a perspective view, partially broken away, showing the manner in which the flat wire cable is connected into the communication wiring of the present invention.
FIG. 28 is a perspective view of a desk of the present invention.
FIG. 29 is a top view of the desk of FIG. 28.
FIG. 30 is a front elevational view of the desk of FIG. 28.
FIG. 31 is an end elevational view of the desk of FIG. 28.
FIG. 32 is a perspective view a desk of the type shown in FIG. 28 employing a privacy screen.
FIG. 33 is a top plan view of the desk of FIG. 32.
FIG. 34 is a front elevational view of the desk of FIG. 32.
FIG. 35 is an end view of the desk of FIG. 32.
FIG. 36 is a perspective view of the desk of FIG. 28 employing tall top panels and a storage unit.
FIG. 37 is a top plan view of the desk of FIG. 36.
FIG. 38 is a front plan view of the desk of FIG. 36.
FIG. 39 is an end elevational view of the desk of FIG. 36.
FIG. 40 is a perspective view of an L-shaped desk of the present invention.
FIG. 41 is a top plan view of the desk of FIG. 40.
FIG. 42 is a front elevational view of the desk of FIG. 40.
FIG. 43 is a perspective view showing the underside of the desk of FIG. 40.
FIG. 44 is a perspective view of the desk of FIG. 40 employing top tall panels, a shelf, and a storage unit.
FIG. 45 is a top plan view of the desk of FIG. 44.
FIG. 46 is a front elevational view of the desk of FIG. 44.
FIG. 47 is an exploded view of the desk of FIG. 40 employing tall top panels and a storage unit.
FIG. 48 is a perspective view of the desk of the present invention, showing the enclosure of the desk area by means of extended bottom panels and short top panels as screening.
FIG. 49 is a perspective view of the underside of the desk of the present invention, showing the electrical connections of the bottom panels with their panel covers removed.
FIG. 50 is an exploded view of the desk top of the desk of the present invention showing the electrical connections in the beam support underneath the desk top.
FIG. 51 is a perspective view of a closet and file in accordance with the present invention.
FIG. 52 is a perspective view of a file cabinet in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, FIG. 1 discloses a perspective view of a typical office lay-out employing the furniture and wall system of the present invention. The system 10 comprises three basic elements: free standing desks 12 and 14; a free standing wall shown generally as 16; and a free standing post and beam assembly, sometimes referred to as archistructure and shown generally by numeral 17. These three elements, combined together, create a highly individualized office environment with clearly defined aisleways and offices, and with a maximum amount of flexibility of doors, windows, and wall constructions. All of the components in this system are modular and all are easily assemblable and disassemblable for revision of the floor plan. While all of the components are related and closely compatible, at the same time they are free standing and separable.
Describing briefly the system components shown in FIG. 1, desk 12 is free standing and includes a work surface and pedestal mounting. The desk is free standing but abuts on one end the free standing wall 16. Another free standing desk 14 in the form of an "L" is positioned on the other side of partial wall 16. This desk is surrounded by a screen in the form of a series of back panels 18, to which shelves 20 are mounted in a manner described below.
The wall section system 16 comprises a plurality of lower wall sections 22 connected end to end in alignment, or at right angles by means of corner connectors 24. The lower wall sections are uniform in size and are constructed so that a number of components can be mounted on top of the lower wall sections. Such components serve as upper covers for the lower wall sections in addition to other functions the components may serve. In some wall sections, the upper cover comprises a flat top cap 26 mounted on the top of the section. In other cases, a short wall top 28 or a short glass panel 30 is mounted on top of the wall section and serves as an upper cover. In other cases, a tall wall top 32 is mounted on top of the lower wall sections. End connectors 34 are connected at the ends of some wall sections in order to make a doorway. A closed doorway may be provided by a separate pocket door unit 36. The pocket door unit has a sliding door 38 that fits within a recess in a pocket panel 40 (see FIG. 2).
The post and beam or "archistructure" system consists of a plurality of beams 42, all substantially the same, mounted on posts 44. The posts shown in FIG. 1 are wall posts that are mounted on the top of wall post supports or connectors 24 at ends of panels. The beams provide an improved definition of office and aisleway spaces and also provide a load supporting mechanism for supporting sliding full doors 46 and half doors or windows 48. A variety of other components described below also can be supported by or housed in the beams.
While the post and beam construction of the present invention is designed to be a free standing unit that is completely separate from the ceiling, if desired, a post extension 50 can be employed on top of a post in order to extend the post construction to or through the ceiling. This may be done in order to convey electrical wires to or from ceiling fixtures or to fasten the post to a ceiling beam in the event that a straight wall is constructed and there are no right angle walls to provide lateral support.
Another component shown in FIG. 1 is a beam 52 of the same construction as beam 42 mounted on a short pole 54 and attached to a conventional end connector 34 at the end. This beam may be provided with a top cap 56 similar to the top cap provided for the lower wall sections and can thus serve as a low railing.
Detailed descriptions of the various components mentioned generally above are shown in the succeeding drawings. In FIG. 2, a pocket door is shown. The door rolls out of the pocket section 40 by means of a wheel 58 on the leading edge of the bottom of the door.
A full door 46 is shown mounted on a beam 42 in FIG. 3. A half door 48 is shown adjacent the full door. The half door is slidably mounted over a wall section 22. An end connector 34 and wall post 44 support an end of beam 42. A cover 60 fits over the junction between the wall post and the beam so as to cover the fasteners by which the two are connected.
An exploded view of the beam and post construction components is shown in FIG. 4. The beams are attached to a wall by means of wall mounts 62. When a corner post 64 is employed, it is attached to the floor by means of a floor mount 66. Alternately, as shown in FIG. 1, a wall post support or end connector 34 may be employed, a shorter wall post 44 being mounted on the top thereof. The exterior cover of post 34 is not shown in this figure.
When the beam is attached to the ceiling, a ceiling extension support or ceiling pass through support 68 is employed. A ceiling pass through member or post extension 50 can be employed for extending the post upwardly through the ceiling for conveying electrical conduit or the like. A beam post connector 70 is employed for connecting post 64 to beam 42. U-shaped cover 60 is employed when a post appears at the end of a wall. A right angle cover 72 is employed at a right angle corner, as shown in FIG. 4, while plate 74 is employed to cover the end of a Tee connection.
A wall post support member 34 is shown mounted to a lower section of wall 16 in FIG. 5. In this figure, wall post 44 is shown raised above its normal resting position on the top of post 34 in order to show the manner in which a conduit 75 extends upwardly through the floor support and the wall post mounted on top.
FIG. 6 shows a different type of post assembly 76 having a light 78 mounted on the top thereof. This corner fixture could also be a sign post, clock, piece of art or the like.
The manner in which the beams are mounted on posts is shown in FIG. 7 and 8. The beam-post connector 70 is square and has an opening 80 through the center leading to the interior of post 44. It is fastened on the top of the post by means of fasteners 82 which are received in appropriate retainers 84 extruded integrally in post 44. Mounting plate 86 has a lower portion 88 extending downwardly therefrom that fits in a mating opening 90 in beam-post connector 70 and is fastened therein by bolt 92. The mounting plate is attached in retainers 94 in extruded beam 42 by means of threaded fasteners 96 that extend through openings in the four corners of plate 86.
As shown in FIG. 8, when the post is extended through the ceiling in order to reach an electrical outlet 98 or the like, a ceiling extension support 68 is mounted on the top of beam-post connector 70, and the ceiling extension support is enclosed by rectangular post extension 50. Electrical conduit 100 may extend from electrical outlet 98 downwardly through the pole electrical distribution below. Also, electrical conduit 102 may extend between the interior of the pole and the upper surface of the beam, which can serve as a raceway for electrical conduit.
The construction of the beam 42 is shown in more detail in FIGS. 9-14. Beam 42 is an extruded member formed in the shape of an "H" with two vertically spaced cross bars. Vertical sides 104 of the beam are thus connected together by an upper cross bar 106 and a lower cross bar 108. The lower edges of sides 104 are provided with upwardly turned flanges 110.
As shown in FIG. 9, the upper surface of beam 42 constitutes a recess 116 with an open top. One use for this recess is to run electrical conduit. Conventional connectors 112 can be employed to interconnect separate components of conduit by means of mating connectors 114 on the ends of the conduits. This construction is conventional. These electrical components can be mounted in the recess 116 in the top of the beam.
On the underside of lower cross bar 108, three J-shaped rails 118 are mounted. As shown in FIG. 12, doors 46 can be suspended in these rails by means of rollers 120 mounted on brackets 122 at the tops of the doors. The doors are mounted in separate rails so that they will slide by each other to open and close the door.
As shown in FIG. 11, a sign 124 can be mounted on flange 110 by means of a mating downwardly facing U-shaped flange 126. A thumb screw 128 can be employed to lock the flanges together at a desired location.
Upper receptacle 116 can also be employed to house a ceiling light 130. This can consist of an upwardly facing reflector 132 and a pair of florescent lights 134 and a deflector 136, causing the light to be deflected in the manner shown. A similar light 138 can be mounted in the recess 140 on the underside of the beam (FIG. 14). Light 138 comprises a reflector 142, a pair of parallel florescent lights 144, and a diffusion grating 146.
The archistructure beam thus serves to support suspended elements, to provide upward and downward lighting and to serve as a raceway for electrical conduit. The 30 function as a raceway is particularly important when there is a break in the lower panels, such as a doorway. With the break in the lower panel, there is no way to pass electrical conduit across the gap without a post and beam extending over the gap.
The novel modular wall construction 16 of the present invention is shown in FIGS. 15-27. Aesthetically, the wall sections appear substantially different from conventional thin open plan partitions. The wall section of the present invention is the same width or thickness (the terms are used interchangeably herein) as a conventional wall, which is about four and five-eighths (45/8) inches thick. The wall thus conveys a thick, sturdy impression. The walls of the present invention comprise two separate components, a plurality of uniform interconnected lower wall sections 22 and a variety of optional components mounted on the lower wall sections. The lower wall sections are designed to be load-supporting to the extent that components can be mounted on top of them. They are not, however, designed to support loads in cantilevered fashion off the side of the wall panels, contrary to most conventional partition systems. The upper wall sections, on the other hand, are completely non-load bearing and may be made of light materials, such as Styrofoam or the like, which provide an appearance of thickness and height and yet are very light. The window components 30 and 148 may be of conventional construction or can be open frames. A pocket door 36 as described above can be attached to one end of the wall system.
Referring to FIG. 16, several wall sections 22 are shown connected together end to end. The sides of the wall sections are covered by removable wall covers 150. These clip easily onto the wall sections and can be removed easily to provide complete access to the interior of the wall sections. As shown in FIG. 17 where the wall covers have been removed, each wall section comprises a rectangular frame 152 consisting of a pair of spaced vertical support members 154 at opposite ends thereof and a pair of spaced horizontal beams 156 and 158 at the upper and lower sides of the frame. Adjacent sections of frame are bolted together by bolts 160. It should be noted that the frame, and particularly the vertical support members, are substantially less wide or thick than the wall itself, thus leaving a substantial gap in between the vertical support posts and the wall covers. This is quite important to the wire handling advantages of the present invention.
On the upper and lower portions of each end of the frame, outwardly extending plates 162 are mounted. These plates serve an important function. As shown in FIG. 27, when two sections of frame are bolted together ends 164 of the plates come into contact with each other and cause the two sections of frame to be maintained in alignment. A gap 166 is provided between the ends of the plates so that the plates are held in fixed position with respect to each other.
As shown in FIG. 20, plates 162 also serve as a widened support flange for the top cap and top wall section mounted on the lower section.
The lower plate 162 also supports wall cover 150. A downwardly extending lip on a flange 170 attached to the wall cover fits within an opening in the lower plate 162 and the flange rests on 162, supporting wall cover 150. The wall cover thus can be pivoted outwardly and inwardly from the top edge around the pivotal connection of flange 170 and the opening in plate 162.
The upper portion of cover 150 is held in a vertical position by means of a resilient clip 172 attached to the inner surface of the wall cover at a position substantially above the bottom. This clip resiliently engages the underside of the inner side of a wire tray or trough 174, which is in turn mounted in the frame and extends between the vertical support members 154.
Wire tray 174 has a partially closed bottom 176 and sides 178 but has an open top and open ends. The tray extends outwardly to the sides substantially beyond the vertical support members 154 (which preferably are 11/4 inch tubing) such that sides 178 are adjacent the inner surfaces of wall covers 150. Clips 172 engage the outer edge of the wire tray, preferably at the bottom, by means of projections 180 or the like on the wire tray or other such conventional resilient connection.
The wire tray is for communications wires and is metallic so that it shields the communications wires from the power wires which are mounted below the wire tray.
As shown in FIGS. 19 and 20, the upper end 182 of wall cover 150 is spaced below the lower edge 184 of top cap 26 or lower edge 186 of wall top 32. This makes it possible for communications wires 190 to be inserted into the interior of the wall sections in a sideways direction through a slot 188 between the top cap or wall top and the top of the wall cover. The wiring will then fall down into the wire tray and be retained there.
This provides an extremely important advantage for the present invention. As shown, when it is desired to string a new communications wire along an entire length of wall through a number of interconnected wall sections, all one has to do is stuff the wire sideways through slot 188 in the adjoining wall sections and the wire will naturally fall into its proper position in the wire tray. There is no need to remove the wall covers and no need to string the wire through any frame openings. The wall can thus accommodate wide variation and frequent changes in communications (typically computer and telephone) wiring without disassembly of the wall system.
The bottom of each wall section is supported on the ground at each end by means of a wide (preferably 4 inches) disc shaped feet 192 which are mounted to the lower beam 158 by means of a threaded sleeve 194 that extends through the beam and is welded thereto. A threaded shaft 196 extends upwardly from foot 192 and is received in threaded sleeve 194. The height of the wall section can be adjusted conveniently by means of a nut 198 formed on the top of shaft 196. Rotation of this nut serves to raise and lower foot 192. Nut 198 is easily accessible simply by unclipping and removing one of the wall covers 150, and it is not necessary to seek access to the adjustment mechanism in any obscure location. While the foot mechanism is basically conventional, the foot itself is quite a bit wider than normal in order to provide additional stability for the wall system and to permit a wall section to stand on its own or to be fastened to the floor structure through provided holes. The adjustment provides a vertical travel of one and one-half (11/2) inches desirably so as to provide a wall height of a minimum of one (1) inch from the floor and a maximum of about two and one-half (21/2) inches from the floor.
At the underside of the wall panel and resting on the floor is a power cable chase 200. This power cable chase runs the entire length of each wall section and continuous contiguously from wall section to wall section. Chase 200 includes vertical side walls 202, upper flanges 204 attached to the top of the side walls and flaring outwardly, and lower flanges 206 attached to the lower edges of the side walls and extending outwardly to lower ends that contact the floor. A central web 208 extends horizontally between side walls 202. The chase thus presents an open top receptacle 210 between the opposite sides of the chase. This receptacle serves as a chase or support tray for power cables 212. The outwardly flared lower flanges 206 extend over feet 192 and conceal them from view, as well as concealing the other mechanical hardware on the underside of the wall sections.
As shown in FIG. 20, power cables 212 can be easily inserted into power chase 200 with the walls in place simply by threading the power cables sideways over the edge of flange 204 and allowing the power cables to drop into receptacle 210. While it appears from FIG. 20 that plate 162 would interfere with the passage of the wire downwardly into the receptacle, by reference to FIGS. 24 or 25 it can be seen that the upper edge of flange 204 is recessed at the point where it intersects plate 162. Wires can thus be laid on top of the plate or can be threaded under the plate through the recess in the flange at the ends of each wall sections.
FIGS. 21 and 22 show how the power chase can be used as a means for connecting electrical outlets at any desired position along the power chase. An electrical outlet assembly 214 comprises a plug receptacle 216 that is positioned vertically at the lower end of wall cover 150. The wall outlet assembly further includes a back portion 218 extending from the lower rear of outlet 216 under the lower edge of wall cover 150 upwardly and inwardly along flange 206, upwardly along flange 202, and then upwardly and outwardly along flange 204. Back portion 218 carries the electrical conduit to a terminal 220 at the top of the back portion, and this terminal is connected to standard connectors for power cables. A flange 222 extends parallel to the upper portion of flange 218 on the inner side of flange 204, and a threaded lock screw 224 extends through flange 222 to clamp the receptacle assembly at any desired longitudinal position along the power chase. As shown in FIG. 22, by loosening lock screw 224, the receptacle can be slid from one end to the other of the wall section as desired and then locked into place.
FIGS. 23, 24, and 25 are similar and show the manner in which the wall sections can be wired into electrical power. In FIG. 23, conventional connectors 228 are suspended from the underside of wire tray 174. Any number of connectors (shown in phantom) can be connected together to form two, four, six, eight or more power terminals. Cable 230 is an illustrative inlet or infeed cable leading from a floor or wall monument to a connector 232 which connects to one of the terminals of connector 228. One outlet cable 234 can extend downwardly to a connector 236 leading to a desk or to a face mounted outlet 214 of the type shown in FIG. 21. Another outlet conduit 238 extends in the generous space between the wall cover and relatively narrow vertical support member 154 directly into the next wall section where it interconnects with another connector 228. With the standard connectors, individual wall sections can easily be wired together with any number of power cables simply by plugging plugs in after unclipping the wall covers. Nothing has to be threaded through any opening in any support members and all the cables can be inserted sideways into the walls. This considerably facilitates installation.
FIG. 24 shows a means by which power can be obtained from an under carpet flat cable 240. A cable 242 connected to connector 228 leads to a terminal box 234 which in turn electrically connects under carpet flat cable with cable 242.
FIG. 25 shows the manner in which a cable 246 can be connected to a source of power from a floor monument 248.
FIG. 26 shows the manner in which communications wiring, such as telephone wiring, can be connected to the wire tray 174. A typical twenty-five (25) pair flat wire cable 250 extending from under a carpet feeds upwardly into the wire tray. As shown in FIG. 7, a terminal connector 252 connects to a bus mechanism 254 into which individual telephone lines 256 can be plugged. Phones can be connected and disconnected easily by removing the wall cover and simply reaching in and plugging in or unplugging the phone. Any other type of conventional telephone wiring system or computer wiring system also would be compatible with this system.
The corner post mechanism 34 attached to the ends of individual wall sections is shown in FIG. 18 with reference to an exemplary right angle connection. The corner post mechanism comprises a metal column 260 having flat sides with openings 262 therein facing the ends of the wall sections. The end column is bolted to the ends of the wall sections through these openings 262. A top cap 264 fits downwardly on the top of the end connector, with a downwardly extending flange 266 serving to attach the top to the connector by means of one of the bolts attaching the connector to the end of the wall section. An appropriate cover 268 (which is a right angle cover in FIG. 18) fits over the metal column 260 to enclose the column. The cover could have three sides if being attached to the end of a single wall section or a single side if attached to a Tee connection wherein three wall sections are interconnected. The end connector column is supported by a plurality of legs 270. The column is formed so that electrical and electronic wiring can pass from one wall section to the other through the connector, or it can extend upwardly through a connector to a post mechanism (as illustrated in FIGS. 4 and 8).
The wall tops mounted on the tops of lower wall sections 16 provide an important feature of the present invention. These wall tops can be short tops 28 or tall tops 32 or any customer specified size higher or lower. Since the wall tops function as room dividers and do not need to function to support wall hung furniture, they can be made inexpensively and yet have a variety of attractive finishes. Desirably, they are formed of a rigid foam plastic such as Styrofoam or the like formed on a rigid base formed of wood 274 or other suitable material. The base can be attached to a cap 276 similar to top cap 26 that fits over plate 162 and is bolted to beam 156 by threaded fastener 278, with each wall top section being bolted to the beam in at least two locations. The surface of the wall top can be decorated with any number of surface textures and materials. A particularly desirable material is a flocking 280 which can be sprayed on the material and gives it an expensive velour appearance at a very reasonable price.
Plate 162 stabilizes wall top 32 in a vertical position and the bolt fastener attachment holds the wall top in proper alignment with the lower wall section on which it is mounted. Because the wall top is light and non-load bearing, complex and expensive fastening and frame mechanisms are not necessary.
To install and remove wall tops or top caps, it is only necessary to unclip the wall cover and bolt or unbolt the desired fixture.
The archistructure and wall system of the present invention contemplate that the furniture will not be wall suspended but will be free standing. To this end, the present invention incorporates a series of free standing modular desks having interchangeable components that provide a wide variety of individually selectible office desk environments, without requiring special wall structures or wall modifications.
A basic desk unit 12 is disclosed in FIGS. 28-31. The desk unit 12 comprises a pair of spaced half width pedestals 282, each having drawers 284. Files are stored longitudinally in the drawers instead of widthwise across the drawers. Each desk has a floating desk top 286, which is spaced above the pedestals and attached to the pedestals by means of a transverse support beam 290 mounted on the underside of the work top and corner braces 292 interconnecting the support beams at the ends with the pedestals 284 (see FIG. 50). The support beam and corner braces desirably are formed sheet metal members, with beam 290 comprising an open top tray that serves to house electrical components. Corner brace 292 comprises a hollow sheet metal brace having a horizontal leg attached to the corner of beam 290 and a vertical leg attached to the inside of the pedestal. The position of the vertical leg can be varied on the pedestal by slotted bolt openings 291 or the like in order to vary the height of the desk top for individual preferences. Electrical cables 294 extend through an opening 296 in the underside of beam 290 and through a mating opening 298 in brace 292 and then through an exit opening 300 in the vertical leg of brace 292. This cable then extends to a terminal connector 302 which can be connected to an infeed source of electrical power. As with the wall sections, power can be received in any number of ways. A floor monument positioned at the bottom rear of the pedestal would be one typical way to transfer power to the desk via terminal 302 and cable 294. Power also can be delivered to the desk by one of the power cables carried by an adjacent wall section or through a post connector. As shown in FIG. 1, desk 12 abuts a wall section on one end thereof. Power cables carried in this wall section could be connected to terminal 302 in the interior of the pedestal or in the interior of the wall section.
The infeed cable 294 is connected to a terminal bus 304 of conventional design. A wire tray 306 is attached to the rear edge 308 of beam 290 and outlets 310 mounted in the trays extend through openings 312 in wall 308 and plug into bus 304. Thus, power cable 294 provides power to a pair of outlets mounted in the wire tray. Another power cable 314 can be connected to the bus and can exit the beam by means of a recess 316 in a side 318 of the beam. This power cable can lead to a computer, lighting or other electrical apparatus. All of these electrical connections can be altered easily by lifting the table top and plugging or unplugging the electrical components. Alternatively, the desk top can be provided with one or more access doors 320 for gaining access to the outlets without lifting the desk top.
Referring to FIGS. 28-31, the pedestals are desirably about seven and one-half (71/2) inches wide. The back of the desk can be open or it can be covered by lower back panels 322, which are desirably about fifteen (15) inches wide. As shown, the desk top desirably extends about halfway over the pedestals so that wiring can be tucked under the edge of the desk between the pedestal and desk top. The same wiring would then run through the wire tray at the back of the desk.
The construction of the lower bottom panels of the desk is shown in FIG. 49. Bottom panels 322 are load bearing panels and comprise a rectangular metal frame 324 preferably formed of channel material. The frame can include a transverse plate 326 in the middle thereof to support electrical outlets 328 which are mounted in openings 330. Electrical conduit 332 extends through adjacent panel sections (which are bolted together) via openings 334 in the frame. As shown in FIG. 49, electrical outlet 328 can provide electrical power to the electrically operated devices at the desk. The panels 322 can be covered with decorative covers and can use the same type of cover as employed in the wall sections, if desired.
In addition to the basic desk unit, a number of optional features can be included. As shown in FIG. 32, the desk can be provided with a privacy screen 334 which can be bolted on the top of panels 322. The privacy screen shown in FIGS. 32-35 is not intended to be a load bearing screen and therefore can be made of the same lightweight type of construction as wall tops 28 and 32. The desk panels, however, are designed to be substantially thinner than the wall panels so as to distinguish between the screens and panels used for a desk and walls.
As shown in FIG. 35, the rear edge of desk top 286 terminates short of privacy screen 334, leaving a gap 336 at the back of the desk. This permits wires to be inserted at the rear edge of the desk top so that they can be carried in wire tray 306. FIG. 34 shows a gap 338 between the desk top and pedestal so that wires can run under the sides of the desk top as well.
FIGS. 36-39 show another type of panel that can be mounted on the basic desk construction shown in FIG. 28. In this embodiment, load bearing top panels 340 are bolted to the top of lower panels 322 and are formed in a similar manner. End panels 342 positioned at right angles to panels 340 are attached to the top of pedestals 282. As shown in FIG. 49, spacers 344 are positioned between upper and lower panels so as to leave a gap 346 between the upper and lower panels. These same spacers are employed between panels 342 and the pedestals. A rubber or elastomer blade 348 (FIG. 36) conceals the gap above the pedestal but still permits wires to be tucked in the gap and concealed in the hollow space between panel 342 and pedestal 382. Thus, even with load bearing top panels, it is still possible to conceal wires between the upper and lower panel sections.
A storage unit 350 is mounted on the load bearing panels above the desk top. Details of the storage unit are shown in the exploded view in FIG. 47, wherein the storage unit is shown to have a door 352, a top panel 354, and a lower panel 356 that is attached in the manner of a shelf.
The manner in which a shelf 358 is attached to the wall panel is shown in FIG. 49. A stamped metal support bracket 360 below the shelf has a U-shaped rear member 362 with a flange that abuts the panel. This flange can be bolted to the panel. The U-shaped rear member provides a groove behind the shelf for concealing electrical wires. It should be noted that there is a gap 364 (see FIG. 38) between the sides of the desk top 286 and side panels 342 which permits wires to be tucked under the side edges of the desk top.
A modification of the desk construction of FIG. 28 is shown in FIGS. 40-43. In this embodiment, the pedestals 322 are positioned at right angles and an additional right angle desk top section 366 is attached at right angles to one end of desk top 286. Both sections of desk top employ support beams 290, with these beams being bolted together where they intersect. Additional support braces 368 are provided for additional support at the corner of the desk. The other features of this type of unit are substantially the same as the previous embodiments.
The L-shaped desk also can have top panels and storage units and shelves mounted on the top panels, as shown in FIGS. 44-46. The storage unit 350 is mounted in the same manner as previously described. The shelf unit is mounted in a similar manner and is attached to the storage unit at one end.
Still another modification of the desk unit of the present invention is shown in FIG. 48. In this unit, a desk top 286 is mounted to a pedestal at one end and to a lower support panel 322 at the other end by the same type of beam and brace arrangement for the FIG. 32 embodiment. In this arrangement, however, the lower support panels not only form back panels but they also form side panels and extend all the way around behind the desk unit. Half height top panels 370 are positioned above the lower panels on one side of the desk in order to vary the aesthetic appearance of the desk unit.
As can be seen, a number of different variations can be achieved with a relatively small number of components. It is important to note that the desk units can include their own screens and panels, even load-bearing panels, and these desks and panels can be arranged independently of the walls and post and beam archistructure. Thus, it is possible to obtain the benefit of wall mounted shelves and storage units without placing limitations on the wall and archistructure system. The wall and archistructure system can thus be employed for space definition, privacy, individuality, and the like, while the load supporting panels used in the desk system can be designed for the more functional aspects of work efficiency and productivity. Even though these units are independent, they are the same height and all include the same type of wiring connections that permit ample power and communications wiring to be distributed to the proper location without the wiring being visible.
Other arrangements of the desk, top panels, storage units, and shelves are possible. The present description is intended to be exemplary only.
Two other elements designed to be compatible with the present invention are shown in FIGS. 51 and 52. FIG. 51 shows a combination personal closet and file 374, with the personal closet 376 being mounted on top of a file unit 378, with the same type of space or groove 380 between the upper and lower sections to create the same compatibility appearance with the other units in the system. The grooves can be provided so that wiring can be hidden in the grooves.
FIG. 52 discloses a file storage unit 384 with upper and lower sections 386 and 388 being separated by a groove 390 that is compatible with the grooves in the other elements of the furniture. The groove again can be deep enough to provide a means for concealing wiring that must pass around the storage unit.
It should be understood that the foregoing is merely exemplary of the preferred practice of the present invention and that various changes and modifications may be made in the arrangements and details of construction of the embodiments disclosed herein without departing from the spirit and scope of the present invention.
|
An integrated wall, archistructural and desk and panel system comprises a series of modular units that integrate into a variety of configurations with a minimum number of components. The desk and panel system comprises a base wall formed of interconnected modular wall panels having a desk back panel formed of modules of the same height and width and appearance as the base wall panels, so the back of the desk can comprise a section of the base wall. The top of the desk is recessed from the vertical support members and back panel of the desk so that modular upper wall panels can be mounted on the back panel and vertical support members, as well as on the base wall panels, to selectively increase the height of the wall panel system and to create a peripheral enclosure for the desk. A hollow transverse desk support beam and hollow inclined frame members provide wiring access to the desk top. The wall structure comprises a free standing modular wall formed of interconnected modules having removable face panels and concealed interior wire storage trays that permit easy wiring access and panel to panel communication. The archistructure comprises a post and beam construction that provides vertical and horizontal wiring channels and an overhead support surface for suspended panels or doors.
| 4
|
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This Application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 61/612,852 filed Mar. 19, 2012, which is incorporated herein by reference in its entirety as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] A modern petroleum refinery is designed to maximize the production of select liquid products from crude oil. In addition to the well known atmospheric and vacuum distillation processes used to provide refined products, many refineries utilize petroleum cokers to further process the residual materials remaining after distillation. The three common coking processes, fluid, flexi and delayed coking, have been used for decades. As such the common operating conditions for petroleum coking are well known throughout the industry.
[0003] During the fill cycle of the coking process, a foam layer forms on the surface of the feedstock as it fills the coke drum. Operators must control foaming within the coke drums otherwise the foam will enter the overhead vapor line resulting in a blockage.
[0004] Management of the silicone anti-foam (AF) agent injection is critical as any carry-over of the silicone material through the overhead vapor line will poison the catalyst found in downstream operating units such as the hydrotreating unit. Thus, operations which use too little silicone based AF agent may foam-over and carry the silicone downstream. However, excessive usage of silicone based AF agent, due to continuous injection, increases costs, may reduce the production of valuable liquids and may lead to an undesirable coke material.
[0005] Delayed coking reactions cause foaming in the coke drums which if uncontrolled can carry heavy tars and coke beyond the coke drum into piping and the distillation system. An uncontrolled foam-over will render the piping and fractionator in the coker inoperable and require a shutdown of the unit for cleaning and repair of any damaged mechanical elements. This is very costly and operators of delayed cokers avoid it by suppressing the foam front in the coke drum that forms during the thermal conversion of coker feedstock to coke and a range of vapors.
[0006] Foam suppression is typically accomplished by injection of high molecular weight silicone material in the form of polydimethylsiloxanes (PDMS) into the coke drum. The PDMS breaks down due to the high temperature in the coke drum and most of the cracked PDMS products vaporize and carry over and contaminate the hydrocarbon liquids recovered in the downstream fractionator. The contamination causes catalyst poisoning in refining units used to further process the coker liquids to finished products.
[0007] Coke drums are used to provide the residence time required for completion of the thermal reactions in a batchwise mode with a continous feed of hot feedstock. When the coke drum is filled, the hot feedstock is switched to another coke drum that has been prepared to receive it. To minimize the amount of PDMS used, it is typically injected only in the latter part of the coke drum fill cycle and during a few subsequent operations when foaming and reactant liquids are closest to the coke drum outlet. During these latter stages of the drum cycle, the drum may experience pressure surges. A sharp, small reduction in pressure can result in a significant increase in foam height risking a foamover. This is particularly true when there has been even a small reduction in the internal temperature of the coke drum.
[0008] Foaming is caused by higher surface tension and viscosity of the partially converted liquids in the coke drum and drum vapors blowing through the liquid. Common ways to reduce the risk of foam-overs and the usage of PDMS are:
1. Providing a higher vapor space in the coke drum when the coke drum fill cycle is complete. This can have negative operating cost implications or require unit modifications. 2. Increasing the temperature of the feed to the coke drum to reduce the surface tension and viscosity of the partially converted liquid reactant mass. The reaction heat is supplied by an upstream fired heater that may be limited in capability to operate at higher temperatures effectively and economically. In some cases there are undesirable process consequences to raising the coking temperature which can affect coke product properties. 3. Adding more aromatic oils to the feedstock. This requires that the added oil, commonly clarified slurry oil (CSO) from a fluid catalytic cracking unit, be provided in enough volume to beneficially affect the properties of the drum liquid. A commonly used material is called decant oil or clarified slurry oil (CSO). If too much is required an undesirable recycle of unconverted CSO can be formed between the delayed coker and the Fluid Catalytic Cracking Unit (FCCU).
[0012] PDMS is delivered to the refiner as a liquid diluted with hydrocarbon liquid usually with kerosene properties. Distribution of this antifoam liquid into the coke drum is typically accomplished by further dilution of the antifoam in a carrier oil, commonly a light and/or heavy gas oil fraction produced by the delayed coker.
[0013] Foam is produced by the actions described above and since the feed and vaporization occurs continuously through the coking cycle, the foam is continuously replenished as the foam bubbles drain. PDMS changes the liquid properties in the foam causing it to drain faster resulting in a reduced height of the froth.
[0014] Further improvements are desired in the current coking process. In particular, improved processes which control foaming in order to enhance liquid yield while improving the coke material are desired. Further, a coking foam control method which reduces the amount of silicone based AF agent used will particularly enhance the coking process.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0015] Feedstocks to all cokers vary from time to time. Therefore, one skilled in the art is accustomed to adjusting injection rates, times and quantities of AF agent to account for the variables of each feedstock. Since delayed coking is by far the most common coking method used today, the current invention will be described in the scope of a delayed coking process. However, those skilled in the art will recognize that the following silicone anti-foaming methods are equally applicable to fluid and flexi coking methods.
[0016] The claimed invention is directed to using highly aromatic hydrocarbon liquids as the carrier fluid used for injecting antifoam into the coke drum. In this manner, the aromaticity of the carrier fluid would modify the properties of the liquids in the foam bubbles which is relatively small compared to the entire mass of partially converted liquid. In this manner the effectiveness of the PDMS for foam drainage is increased and less PDMS may be used.
[0017] In an embodiment of the invention, the concentration of PDMS in the injecting fluid is lowered by virtue of using a highly aromatic carrier oil.
[0018] In a further embodiment of the invention, the amount of PDMS that is blended with the carrier oil is reduced by 30% or more relative to prior art compositions.
[0019] In an embodiment of the invention, the carrier oil that is used to blend the PDMS has an aromatic concentration by weight greater than 90%.
[0020] Carrier fluids that can be considered for the service include but may not be limited to: Light Cycle oil, heavy cycle oil or clarified slurry oil (CSO) from a FCCU; Liquids from an ethylene pyrolysis unit; or Gas Oils from the coking or re-cracking of previously cracked hydrocarbons such as the coking of CSO.
[0021] In an embodiment of the invention, PDMS is injected into the coke drum especially in the latter part of the coke drum cycle and a few subsequent steps through the drum depressuring to the coker blowdown system for steam, quench steam and hydrocarbon recovery. Another embodiment of the invention is directed to the use of carrier fluid for PDMS that is more aromatic than the liquids produced in the delayed coker. CSO is a preferred carrier because it contains a significant amount of mass that will not vaporize in most coke drums and therefore provides a longer period of time to affect foam drainage.
[0022] A typical coking operation uses two coking drums. Each drum cycles through eight standard steps:
1. Drum fill/coke conversion—Feedstock enters a preheated drum, which begins to fill with coke. (The time required to fill the drum to the desired level is referred to herein as the fill cycle, fill step or fill time.) Once a drum is full, feedstock is directed to an empty drum and the full drum is brought off-line. 2. Steamout—Steam stripping to help strip out any residual liquid hydrocarbon from the coke. 3. Water quench—Quenching with water of the full, off-line drum until the coke in the drum is cooled to between 200 and 275° F. 4. Draining—Quench water is removed from the off-line coke drum. 5. Unheading—Removal of the top and bottom drum heads from the off-line coke drum. 6. Decoking—High pressure water is used to cut the coke inside the drum. Coke and water pass through the bottom of the drum into the coke-handling system. 7. Heading and testing—Reinstallation of the drum heads and pressure testing of the drum with steam. 8. Warm up—Steam and hot hydrocarbon vapors from the on-line drum are directed through the off-line coke drum.
[0031] The drum fill/coke conversion step primarily determines the cycle time for the coke drum. The desired coke product and desired liquid production dictate the time required for the initial step. In most coking operations, cycle times vary between twelve and twenty-four hours with a twenty-four hour cycle being most common. Under these conditions and depending upon drum size, drum processing rates may vary between about 8000 barrels per day and 50000 barrels per day (bpd).
[0032] Depending on drum size, fill times may vary between about 8 to about 18 hours. Fill times are readily calculated by those skilled in the art based on the internal volume of coke drum and the feedstock flow rate into the drum. To maximize production, the drum is filled as completely as possible. Typically, nuclear level indicators (not shown) or other suitable devices are used to monitor the fluid level in the drum at various filling stages. Overfilling of the drum can lead to “foam-over” and fouling of overhead vapor line with coke.
[0033] AF agent is used to control foam levels and to manipulate the formation of coke. In general AF agent is injected through any conventional nozzle located near the top of the drum. AF agent is generally stored in a tank or other similar device and is pre-heated to a temperature between about 425° C. to about 460° C. (about 800° F. to about 860° F.), as known by those skilled in the art.
[0034] During filling of the coke drum and during the conversion of the feedstock to coke, the feedstock undergoes a thermal cracking process wherein additional liquid material and gas are produced. The coke drum product, in vapor and gaseous form, exits the drum through an overhead vapor line. Typically, drum outlet vapor temperature is between 410° C. and 455° C. (775° F. and 850° F.). The produced vapors are quenched in overhead vapor line and subsequently pass to a processing unit such as a coker fractionator.
[0035] In the above described process, injection of AF agent takes place at the conclusion of the fill step of the coking cycle. Most coke drums carry a nozzle or other port suitable for injecting AF agent. As known to those skilled in the art, injection of AF agent preferably occurs at a pressure sufficient to ensure that the AF agent reaches the foam layer prior to being vaporized and swept out of the drum. AF agent injection rate (pressure and volume/time) will vary depending on the feedstock and foam layer height in the drum. Under standard operating procedures, AF agent injection begins when the drum is about two-thirds full.
[0036] In one aspect, the current invention provides a method of using an AF agent comprising a carrier fluid to preclude foam-over in the coking process. In an embodiment of the invention, the AF agent is PDMS and the carrier fluid is CSO. Slurry oil is a product of the catalytic cracking unit commonly found in a petroleum refinery. While it is known to use slurry oil as a component of the feedstock to the coker, prior art methods have not used slurry oil as an AF agent. Preferably, the slurry oil is a clarified slurry oil that is substantially free of catalyst and other materials commonly found in the bottoms of the catalytic cracker.
[0037] Other embodiments of the current invention will be apparent to those skilled in the art from a consideration of this specification or practice of the invention disclosed herein. However, the foregoing specification is considered merely exemplary of the preferred embodiments of the current invention. The following claims define the scope of the current invention.
|
The current invention provides an improved petroleum coking process wherein the risk of silicone poisoning of units downstream of the coke drums is reduced. The method of the current invention controls the foam layer within the coke drum by injection of a silicone anti-foam agent in a highly aromatic carrier fluid such as slurry oil.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority, and incorporate by reference the entire disclosure of Japanese Patent Application No. 2002-38041, filed on Feb. 15, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a head suspension, and particularly to a structure of a head suspension for supporting a magnetic head to read/write data from and on a magnetic disk in an oscillation-type actuator which is used in a magnetic disk apparatus. The magnetic disk apparatus us used as an external storage device for a computer.
[0004] 2. Description of the Prior Art
[0005] Recently, track pitches have been made smaller to increase the storage capacity in a magnetic disk apparatus, and accordingly, the frequency band to control the position of a magnetic head which moves on tracks has become higher. In control using such a high frequency band, it is necessary for the frequency of the mechanical resonance point of the suspension to be high so as not to make the controlling frequency of the head suspension operate the head at the mechanical resonance frequency of the suspension. Namely, a high resonant frequency head suspension is required.
[0006] To enhance the resonante frequency of the head suspension to operate the magnetic head, it has been conventionally proposed to increase the thickness of the head suspension entirely or partially, to welding two plates in order to partially increase the thickness of the head suspension, or to provide ribs on the head suspension. Namely, in the prior art, the frequency of the resonance point is enhanced by increasing a spring constant of the head suspension.
[0007] However, such solution in the prior art increases the mass of the whole suspension, thus resulting in an influence on floating of a magnetic head slider which is attached to a tip of the head suspension. Namely, the rigidity of the head suspension in the upward and downward direction is so large that uneven floating takes place, or the mass of the whole suspension is increased, thus leading to a reduce shock resistance. An increase in the mass of the suspension makes large a drive system to drive the head suspension and increases the power consumption thereof.
[0008] To solve the problems of the prior art, it has been proposed that two anisotropic fiber-reinforced composite layers are used to connect the head slider of the head suspension and a load beam portion of a support of the head slider (see Japanese Kokai No. 8-212741).
[0009] However, in a head suspension structure described in Kokai No. 8-212741 in which the fibers are laminated with the orientations degree intersecting at 90 degrees, no optimization of the laminate structure is obtained. Therefore, the resonance frequency of the head suspension in the seeking direction tends to be lower than that of a conventional head suspension using SUS material. Also, there is a possibility that the rigidity of the head suspension in the upward and downward direction is increased.
SUMMARY OF THE INVENTION
[0010] The present invention is aimed to provide a head suspension of a good shock resistance and high resonance which contributes to development of an improved magnetic disk apparatus, in which the head suspension is made of laminated anisotropic material so that the external flexural rigidity is small and the internal flexural rigidity is large, whereby the rigidity of the head suspension, which has an influence on the floating of a head slider, can be reduced.
[0011] To achieve the above purpose, the present invention can be embodied in the following first to fifth embodiments.
[0012] In a head suspension of an oscillation-type actuator, in a first embodiment, in which a head to read/write data is provided at a tip end of the head suspension, at least a part of the head suspension is made of an anisotropic material whose rigidity varies depending on the direction.
[0013] In a head suspension of a second embodiment, the anisotropic material referred to in the first embodiment forms a lamination structure in which the layers have different orientations of the high rigidity are different in layers.
[0014] In a head suspension of a third embodiment, a pivot is provided near a head mounting position of the head suspension of the first or the second embodiment to apply pressure to the head toward a recording medium from or on which data is read/written by the head.
[0015] In a head suspension of a fourth embodiment, a rigid body is formed on the head suspension in any of first through the third embodiment, by thickening a part of the head suspension more than the other portion thereof.
[0016] In a head suspension of a fifth embodiment, the rigid body of the head suspension of the forth embodiment has a thickness larger than that of the remaining portion, by increasing the number of the anisotropic layers to be laminated.
[0017] In the head suspension of the above described embodiments, the anisotropic layers are laminated so that the external flexural rigidity of the head suspension is small and the internal flexural rigidity is large. Consequently, for example, if an anisotropic material such as a carbon fiber reinforced plastic (CFRP) is used, a three-layer structure can be obtained in which a layer of a carbon fiber reinforced plastic (CFRP) oriented in the longitudinal direction of the suspension is sandwiched between layers of carbon fiber reinforced plastics (CFRP) oriented in the width direction thereof. Thus, a head suspension having low rigid, high resonance, light and good shock resistance can be designed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will be more clearly understood from the description as set forth below with references to the accompanying drawings, wherein:
[0019] [0019]FIG. 1A is a left side view showing a conventional head actuator having a head suspension.
[0020] [0020]FIG. 1B is a plan view showing a conventional head actuator having a head suspension.
[0021] [0021]FIG. 1C is a right side view showing a conventional head actuator having a head suspension.
[0022] [0022]FIG. 2A is a perspective view showing the first embodiment of a head suspension according to the present invention.
[0023] [0023]FIG. 2B is an enlarged partial view in a part B of FIG. 2A.
[0024] [0024]FIG. 2C is an exploded perspective view showing orientations of three anisotropic layers laminated as shown in FIG. 2B by way of example.
[0025] [0025]FIG. 3 is an exploded perspective view of the same part as FIG. 2C, showing orientations of carbon fibers when the anisotropic layers of the FIG. 2C are made of CFRP.
[0026] [0026]FIG. 4 is a table explaining an effect of a head suspension of the present invention.
[0027] [0027]FIG. 5A is an exploded perspective view explaining orientations of anisotropic layers when the head suspension shown in FIG. 2A has a five-layer structure, by way of example.
[0028] [0028]FIG. 5B is an exploded perspective view showing another example of orientations of anisotropic layers when the head suspension shown in FIG. 2A has a five-layer structure.
[0029] [0029]FIG. 6A is an exploded perspective view showing another example of orientations of anisotropic layers explained in FIG. 2C.
[0030] [0030]FIG. 6B is an exploded perspective view showing an example of orientations of anisotropic layers when the head suspension has a five-layer structure.
[0031] [0031]FIG. 7A is a perspective view of a head suspension structure of a second embodiment of the present invention in which a pivot is provided on the head suspension to press a head slider.
[0032] [0032]FIG. 7B is an enlarged partial view side of a tip end of the head suspension shown in FIG. 7A.
[0033] [0033]FIG. 7C is an explanatory view explaining a rotating direction of a head slider shown in FIG. 7A and FIG. 7B by the pivot.
[0034] [0034]FIG. 8A is a perspective view showing a third embodiment of a head suspension of the present invention.
[0035] [0035]FIG. 8B is an enlarged partial view of a main part of FIG. 8A.
[0036] [0036]FIG. 9A is a perspective view showing a forth embodiment of a head suspension of the present invention.
[0037] [0037]FIG. 9B is an enlarged partial view of a main part of FIG. 9A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Before describing the preferred embodiments, an explanation will be given of a head actuator using a conventional head suspension shown in FIGS. 1A to 1 C.
[0039] [0039]FIGS. 1A through 1C show a structure of a head actuator 60 having a conventional head suspension 74 in a disk apparatus. FIG. 1A is a left side view of the head actuator 60 , FIG. 1B is a plan view of the head actuator 60 , and FIG. 1C is a right side view of the head actuator 60 . The head actuator 60 is attached to a rotation shaft 76 , such as a pin, and oscillates about the rotation shaft 76 . Carriage arms 72 which are in the form of a comb in side view are provided on one side of the rotation shaft 76 . One or two head suspension(s) 74 is(are) attached to the tip end of each carriage arm 72 . At the tip ends of the head suspensions 74 , head sliders 71 having heads to transmit and receive the data to and from a disk medium are provided.
[0040] Two supporting arms 73 are provided on the side opposite to the carriage arm 72 with respect to the rotation shaft 76 , and a flat coil 75 is interposed between the supporting arms 73 . The flat coil 75 is opposed to a magnetic circuit (not shown) provided on the base side of a disk apparatus, so that the head actuator 60 oscillates according to the value of a current flowing in the flat coil 75 .
[0041] A base 70 of each head suspension 74 is joined to the tip end of the corresponding carriage arm 72 . A head fine movement mechanism may be optionally provided on the joint base 70 of each head suspension 74 to finely move the head suspension 74 independently of the oscillation of the head actuator 60 . Ribs 77 are partially provided on the head suspension 74 to enhance the resonance frequency in the conventional head suspension 74 .
[0042] For these reasons, the mass of the entirety of the conventional head suspension 74 is increased, thus resulting in an advance influence on the floating of the head sliders 71 mounted to the tip ends of the head suspensions 74 or in an increase of the rigidity of the head suspensions 74 in the upward and downward directions, leading to uneven floating.
[0043] [0043]FIG. 2A shows a head suspension 11 according to a first embodiment of the present invention, which is attached at the same position as the head suspension 74 shown in FIG. 1A through FIG. 1C. A substantially Ushaped hole 2 is provided at the tip end of the spring arm 5 which constitutes the head suspension 11 . A hinge 3 and a slider mounting portion 4 are formed in the substantially U-shaped hole 2 . A head slider 1 having an inductance head or an MR head is mounted to the slider mounting portion 4 .
[0044] The spring arm 5 in the first embodiment is comprised of three layers of anisotropic material 20 having different rigidities (elasticity moduli) depending on the direction, as shown in FIG. 2B. Each anisotropic layer 20 exhibits a high elasticity modulus in a direction (represented by thick arrows) and a low elasticity modulus in another direction (represented by thin arrows) perpendicular to the first direction, as shown in FIG. 2C. In the first embodiment, the three anisotropic layers 20 are laminated to constitute the spring arm 5 . Intermediate anisotropic layer 20 c exhibits a high elasticity modulus in a direction identical to the center line C-C of the head suspension 11 . The upper and lower anisotropic layers 20 a and 20 b between which the anisotropic material 20 c is interposed exhibits a high elasticity modulus in a direction perpendicular to the direction in which the intermediate anisotropic layer 20 c exhibits the high elasticity modulus. (the width direction of the head suspension 11 ).
[0045] If the anisotropic layers 20 which form the spring arm 5 are laminated as shown in FIG. 2C, the flexural rigidity of the spring arm 5 in the upward and downward direction is reduced, so that the rigidity which has an influence on the floating of the head slider 1 can be restricted. Furthermore, the internal flexural rigidity of the spring arm 5 is increased, and the resonance frequency of the head suspension 11 is increased.
[0046] [0046]FIG. 3 shows an embodiment in which anisotropic layers 20 A made of carbon fiber reinforced plastic (CFRP) are used instead of the anisotropic layers 20 shown in FIG. 2C. The anisotropic layers 20 A are each in the form of a plate made of parallel carbon fibers 21 covered with a filler agent 22 such as resin. The direction in which it exhibits a high elasticity modulus extends along the carbon fibers. Therefore, in this embodiment, the anisotropic materials 20 A are oriented, so that the carbon fibers 21 extend in directions in which the corresponding anisotropic layers 20 A to 20 C have high elasticity moduli.
[0047] As described above, the spring arm 5 is formed by a laminate structure in which the carbon fibers 21 of the adjacent upper and lower layers extend in orthogonal directions, and thus, the flexural rigidity direction of the head suspension 11 in the upward and downward direction is reduced and the rigidity which has an influence on the floating of the head slider 1 restricted. Furthermore, the internal flexural rigidity of the spring arm is increased, thus resulting in an increase of the resonance frequency of the head suspension 11 .
[0048] [0048]FIG. 4 shows properties of the head suspension 11 made of the anisotropic layers 20 A, in comparison with those of head suspension made of stainless steel (SUS) which has been conventionally used. As seen in FIG. 4, if the conventional SUS 304 (0.08C-18Cr-8Ni) is used, the resonance frequency is increased, but the rigidity is also increased. Further, the equivalent mass is also increased, and thus, a shock resistance is reduced. On the other hand, if the head suspension 11 is formed by the spring arm 5 which is made of laminated anisotropic layers 20 A, as shown in FIG. 3, it is possible to increase the resonance frequency without increasing the rigidity of the head suspension 1 . Moreover, the equivalent mass is reduced, and therefore, the shock resistance of the head suspension 11 can be improved.
[0049] [0049]FIG. 5A and FIG. 5B shows two examples of orientations of the anisotropic layers 20 when the head suspension shown in FIG. 2 A is comprised of a spring arm 5 of five-layer structure. In an example of FIG. 5A, the anisotropic layers 20 d and 20 e are additionally interposed between the upper anisotropic layer 20 a and the anisotropic layer 20 c shown in FIG. 2C and between the lower anisotropic layer 20 b and the anisotropic layer 20 C, respectively. The anisotropic layers 20 d , 20 e exhibits the high elasticity modulus in a direction (identical to the direction of the anisotropic layer 20 c and parallel with the center line of the head suspension 11 ) perpendicular to a direction in which the anisotropic layers 20 a , 20 b exhibit the high elasticity modulus.
[0050] To the contrary, in an example in FIG. 5B, the anisotropic layer 20 f having a high elasticity modulus oriented in the width direction of the head suspension 11 is used as the middle layer of the five layers. Two upper anisotropic layers and two lower anisotropic layers 20 g , 20 h , 20 i , 20 j , are arranged as shown in the drawing, so that their higher elasticity modulus directions are alternatively orthogonal to each other. The example of FIG. 5 A can provide a higher resonance frequency than that of FIG. 5B, however, the example of FIG. 5B could be more advantageous in accordance with the usage.
[0051] [0051]FIG. 6A shows another example of the orientations of the anisotropic material shown in Fig, 2 C. In this example, the high elasticity modulus direction of the intermediate anisotropic layer 20 c is identical to the center line C-C of the head suspension 11 shown in FIG. 2A. The high elasticity modulus directions of the upper and lower anisotropic layers 20 k and 20 m between which the anisotropic layer 20 c is interposed from 45° with respect to the high elasticity modulus direction of the anisotropic layer 20 c . The high elasticity modulus directions of the anisotropic layers 20 k and 20 m are orthogonal to each other.
[0052] In an example of FIG. 6B, the outermost anisotropic layers 20 p and 20 q are respectively laminated on the upper and lower anisotropic layers 20 k , 20 m between which the anisotropic layer 20 c shown in FIG. 6A is interposed. The high elasticity modulus directions of the anisotropic layers 20 p and 20 q are perpendicular to those of the anisotropic layers 20 k and 20 m , respectively. The anisotropic layers 20 p and 20 k can be replaced with the anisotropic layers 20 m and 20 q and vice versa. As can be seen from the foregoing, the high elasticity modulus directions of the anisotropic layers 20 in the present invention are not limited to the direction identical to the center line of the head suspension 11 and the direction perpendicular thereto.
[0053] [0053]FIG. 7A shows a head suspension 12 of a second embodiment of the present invention. The second embodiment differs from the first embodiment in the point that a pivot 6 is provided on the tip end of the head suspension 5 explained with reference to the first embodiment, to press the head slider 1 .
[0054] To provide the pivot 6 on the tip end of the head suspension 5 , the portion of the slider attachment portion 4 opposite to the hinge 3 in the first embodiment is cut away. The substantially U-shaped hole 2 , in the first embodiment, is replaced with a substantially W-shaped hole 8 due to a pivot holding portion 7 on which the pivot 6 is formed.
[0055] The pivot 6 is projected from the pivot holding portion 7 toward the head slider 1 , as shown in FIG. 7B, to thereby press the back of the head slider 1 , so that the head-provided side of the head slider 1 comes close to a magnetic recording medium. The head suspension 12 in the second embodiment can apply the pressing load to the back of the head slider 1 , due to the pivot 6 .
[0056] [0056]FIG. 7C shows a back surface of the head slider 1 , in which the portion to be pressed by the pivot 6 is indicated by X. Due to the pivot 6 , the head slider 1 can rotate in directions indicated by Y and Z about the point X at which the force is applied by the pivot.
[0057] [0057]FIG. 8A shows a head suspension 13 of a third embodiment of the present invention. In the head suspension 13 of the third embodiment, a rigid body 9 is provided on a part of the head suspension 11 of the first embodiment. In the third embodiment, the spring arm 5 is comprised of four anisotropic layers 20 A of CFRP. The rigid body 9 is made of one anisotropic layer 20 A superimposed on each of the upper and lower surfaces of the spring arm 5 .
[0058] [0058]FIG. 8B shows an enlarged view of an end of the rigid body 9 . In the spring arm 5 of the third embodiment, the two intermediate anisotropic layers 20 X in which the carbon fibers 21 are oriented in the longitudinal direction of the head suspension 13 are used, and in the upper and lower anisotropic layers 20 Y in which the carbon fibers 21 are oriented in a direction perpendicular to the longitudinal direction are used. The rigid body 9 is constructed by the anisotropic layers 20 X that have the carbon fibers 21 oriented in the longitudinal direction and that are laminated in the upward and downward direction of the spring arm 5 . Namely, the rigid body 9 is symmetric with respect to the spring arm 5 in the upward and downward direction.
[0059] [0059]FIG. 9A shows a head suspension 14 of a fourth embodiment of the present invention. In the head suspension 14 of the fourth embodiment, a rigid body 10 is provided on a part of the head suspension 11 of the first embodiment. In the fourth embodiment, the spring arm 5 is made of four anisotropic layers 20 A of CFRP. The rigid body 9 is formed by inserting two the anisotropic layer 20 A between the two intermediate layers of the spring arm 5 .
[0060] [0060]FIG. 9B is an enlarged view of tip end of the rigid body 10 . In the spring arm 5 of the fourth embodiment, the two intermediate anisotropic layers 20 X have carbon fibers 21 oriented in the longitudinal direction of the head suspension 13 and the upper and lower anisotropic layers 20 Y have carbon fibers oriented in direction perpendicular to the longitudinal direction of the head suspension 13 . The rigid body 10 is formed of the anisotropic layers 20 X in which the carbon fibers 21 are oriented in the longitudinal direction of the head suspension 13 and which are interposed between the two intermediate layers 20 X of the spring arm 5 . Namely, the rigid body 10 is symmetric with respect to the spring arm 5 in the upward and downward direction.
[0061] Because the thickness of the anisotropic layers 20 X, 20 Y is very small, the rigid body 9 or 10 provided on the head suspension 13 or 14 hardly increases the weight of the head suspension 13 or 14 .
[0062] In the above described embodiments, although the carbon fiber reinforce plastic is used as an anisotropic material, the kind of the anisotropic material is not limited thereto.
[0063] As explained above, in a head suspension of the present invention, since the anisotropic layers are laminated so that the external flexural rigidity of the head suspension is small and the internal flexural rigidity is large, if, for example, the anisotropic material such as CFRP is used, a three-layer structure in which a layer having carbon fibers oriented in the longitudinal direction of the suspension is interposed between layers having carbon fibers oriented in the width direction of the suspension can be obtained. Thus, a magnetic head suspension having a high shock-resistance and a high resonance frequency and a low rigidity having less influence on the floating can be provided, and this greatly contributes to an improvement in a magnetic disk apparatus.
|
The present invention is aimed to provide a head suspension having a high resonant frequency, high shock resistance and low rigidity, which greatly contributes to an improvement of a magnetic disk apparatus. In an oscillation-type actuator, at least a part of a spring arm of the head suspension having a data reading/writing head slider 1 is made of an anisotropic layer whose rigidity varies in accordance with a direction. In this case, the anisotropic layer is laminated so that the high rigidity modulus orientation direction is different according to layer.
| 6
|
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a device for monitoring data on consumable goods. More particularly, the present invention relates to a device for monitoring the consumption, life span and nutritional value of various foods and related items.
2. Description of the Prior Art
In this ever increasingly fast-paced world, it is becoming more and more difficult for households to keep track of the amount of food in the home, the shelf life of the food, and the food consumed by individual household members. U.S. Pat. Nos. 5,335,509 and 5,487,276 disclose systems which monitor the expiration dates of various products and provide an alert when a product is close to its expiration date. However, these systems require an extensive amount of user input. Furthermore, these systems do not provide any information regarding the quantity of each product that remains or the nutritional information for the food that is consumed.
Accordingly, there is a need for a device which can efficiently monitor the quantity and life span of food and related products in a household and can also monitor caloric and nutritional intake for individual household members.
SUMMARY OF THE INVENTION
The present invention relates to an appliance door incorporating a monitor and display system. The system includes a microprocessor with memory means for storing information about consumer goods and individual users. Various means are associated with the microprocessor for inputting information regarding the consumer goods, including nutritional information, and individual user identifiers. An individual user can enter his or her identifier and an associated amount of goods consumed by the individual. The system computes and stores nutritional information related to the goods consumed by each individual user. The information can be displayed. A printer may also be provided for outputting the information.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial isometric view of a refrigerator door incorporating the present invention.
FIG. 2 is a front elevation view of the input/output (I/O) center of the present invention.
FIG. 3 is a front elevation view of the preferred scale assembly of the present invention.
FIG. 4 is a side elevation view of the scale assembly taken along the lines 4--4 in FIG. 3.
FIG. 5 is a side elevation view of the scale assembly, as shown in FIG. 4, with the extension member extended.
FIG. 6 is a side elevation view of the scale assembly, as shown in FIG. 4, in a cleaning position.
FIG. 7 shows the screen displaying an exemplary main menu.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiment will be described with reference to the drawing figures where like numerals represent like elements throughout.
The device 2 of the present invention generally includes a processor assembly 50, an input/output (I/O) center 8 and an associated scale assembly 32 which are integrated into the refrigerator door 20. The processor assembly 50 generally comprises a microprocessor 52 will be described hereinafter. The I/O center 8, as shown in FIG. 2, generally comprises a visual display 10, a keyboard 12, a printer 14 and a scanning wand or pen 16. The device 2 is normally powered by the host appliance, however, it is preferred that a back-up battery be supplied as a safe guard against power interruptions.
The video screen 10 is preferably a flat screen of the type commonly used with lap top computers. The screen 10 displays menus which prompt the user and also provides output requested by the user. Alternatively, the screen 10 could be a touch screen. In this case, the keyboard 12 may not be required. The printer 14 is a standard small printer of the type frequently used with cash register receipts which allows the user to print desired information.
The keyboard 12 and pen 16 allow the user to input information into the device 2. The keyboard 12 can be provided in various configurations including alpha-numeric characters, directional movement keys and command keys. The keyboard 12 is preferably fixed in the device. Alternatively, the keyboard can be connected to the device 2 through a cord (not shown) or can be provided with remote access capability. The pen 16 is preferably connected to the device 2 through the cord 22. Recess 18 is provided to secure the pen 16 adjacent to the I/O center 8. The pen 16 is preferably used to read UPC bar codes or other symbologies commonly used in the labeling of consumer goods.
A scale assembly 32 is provided in communication with the device 2. In the preferred embodiment, the scale assembly 32 is provided as part of the refrigerator 20 ice and water dispenser 30. The ice and water assembly drainage shelf 34 is positioned on load cells 46 which communicate with the microprocessor assembly 52. An object to be weighed is placed on the shelf 34 and the load cells communicate the weight to the microprocessor 52. To accommodate larger objects, the shelf 34 is preferably provided with an extension member 36 which is pivotably connected at the outer edge of the shelf 34 by pivot pins 38. The extension member 36 is extended forward of the refrigerator door to allow taller and wider objects to be placed thereon. To facilitate cleaning, the shelf 34 and extension member 36 are pivoted upwardly as shown in FIG. 6. In the event that there is no drainage shelf 34 available, the weighing function may be provided through a peripheral scale which is connected to the computer or the information may be transferred via keyboard 12.
As shown in FIG. 7, the screen 10 shows a default screen including the date, time and main menu. The main menu allows the user to select various options quickly by using the selected function on the keyboard 12. These program selection techniques will be familiar to individuals who have used personal computers.
It is contemplated that the principal means of entering data about the food stuffs will be the use of the UPC bar code which is commonly found on packaged products. This data will generally be entered by swiping the light pen across the bar code on the product. Alternatively, the product number which is generally printed directly below the bar code may be entered into memory through the keyboard. In most instances, the UPC code will contain information about the size and quantity of the product but will not contain nutritional information. In those cases where the nutritional information is not provided, the data may need to be entered through the keyboard 12.
In those instances where the products being stored are not an original package, the UPC code on the original package may be scanned and the quantity data modified through use of the keyboard 12. In the event that the quantity is not critical to the information, the UPC code from the original package may be copied and applied to the package through self stick labels or other means. When the item identifier is the product's UPC code the microprocessor will compare it's code with the stored codes to update the inventory. Through the use of codes, the microprocessor will be able to determine what the food product is, the current inventory and, when entered, the nutritional information regarding each portion per serving.
Each time a product is presented to the system, the user will be prompted to enter any relevant expiration date together with any relevant storage data. Obviously, some products will not have an expiration date, however, it may still be desirable to know the date on which the product was first entered into the system for historical data to determine the rate at which the product is used.
If an original bar code is not available for scanning, the user can type in an identifier, for example, "p e a s". The screen 10 will then prompt the user to enter the weight quantity, expiration date, caloric information, and location in which the item is stored. The microprocessor can maintain all of this information, regarding the quantity, location, and expiration date of stored products to be utilized by the user through the main menu and the other options.
The processor assembly 50 with microprocessor 52 is preferably about the size of currently available lap top computers. Many of these devices are extremely powerful computing devices and contain substantial memory. Accordingly, the microprocessor 52 will have the memory capacity to retain basic, product specific nutritional information about consumables, and to be programed with the symbologies and decoding logic necessary for reading those symbologies commonly associated with consumer goods. While it is possible to incorporate a drive means into the microprocessor for loading data into the memory, it is currently preferred that the drive means be a peripheral device in order to save appliance space. It is also contemplated that the device would be pre-loaded with common software and information, such as the codes and nutritional information, prior to sale.
As can be seen from the above, the present device will provide a user with a readily available means of imputing data regarding food stuffs and medications at an convenient location and will provide a convenient means for determining the consumption of the same. For instance, the user may determine that four portions of a particular product are desired for a particular meal. Through the use of the nutritional information, the user can determine the weight amount of product which is equivalent to four portions. The scale assembly 32 is then used to measure the proper portions of product. This procedure can be followed for each item which forms part of the meal. The nutritional information can then be collected, totaled and divided among the four individuals. The nutritional information may be maintained individually or collectively for those meals which are shared equally.
In the event that the user consumes takeout food or food which is not prepared in the home, this information may added through the UPC code or the keyboard. However, it may be more difficult to track nutritional information for fast food items which often are not as fully described. In response to this concern, it is contemplated that the processor memory will include approximated nutritional food values for generally consumed foods and treats so that the values may be selected and entered by an associated code which can be found by scrolling through a list display on screen 10.
In the event that a user is taking medications which may have an adverse reaction based on certain food stuffs, those food stuffs may be identified on that user's record and the program will scan the nutritional information of entered food stuffs to determine if such potentially adverse acting ingredients are present.
If an individual wants to enter food consumed or added, the individual will select the appropriate record and will then enter the food items and the amount thereof. The item can be entered either through the keyboard or by swiping the pen 16 over a code. The microprocessor 52 will update the individual record and track the additions to or deletions from the total inventory. This allows the microprocessor to keep a current inventory and to determine the rate at which products are used and when they are running low. Based on the user's input as to desired inventory levels, the microprocessor will determine when the inventory is low and store a notation of the same in a shopping list memory.
To find out the items on the shopping list, the user simply polls the inventory program. The user can then choose among a summary of input, a total inventory, a shopping list, or a history for product use. The summary of input would allow a user to track all the items entered. This information could be displayed on the screen or printed out in hard format. The inventory function would allow the user to display or print out the complete history of products stored in the system. Finally, the product life option will allow the individual to enter an item identifier, either with the light pen 16 or the keyboard 12, to determine the length of time it has been stored which will be displayed on the screen 10 or printed with the printer 14.
The main menu also gives the user the option of storing medication information. Upon selection of this option, the user will be prompted to enter a name. The user can then enter the name(s) of the medication(s), the frequency of use, the dosage times and rates and any special instructions, such take with food. Each time a medication is due, the system 2 will cause a indicator to flash on the screen 10. An audio signal can also be produced. The processor memory may also store medical information for use in alerting the user if a potentially harmful combination of medicines has been entered.
In addition to maintaining food and medical information, incorporation of the present invention into the appliance will permit the user to control the appliance features directly from the device 2. For instance, temperature, absolute humidity, defrost cycles and relative humidity may be monitored and adjusted without the need for opening the appliance door. Accordingly, the condition which is being adjusted will not be influenced by exposure to ambient conditions outside of the appliance. An additional advantage which is believed to stem from incorporation of the device directly into the appliance is the ability to generate a prompt or alert signal from the device when the appliance door is open. Through the use of such a prompt, the user will be reminded of the need to update the system information based on that use of the appliance.
It will be understood that the user will be free to assign different degrees of the importance to the various functions and that the usefulness of the invention will be influenced by the accuracy of the information.
|
The present invention concerns an appliance door that incorporates a monitor and display system for tracking the inventory and use of consumer goods. The device includes a microprocessor having a memory that stores product specific information regarding the consumer goods, and is capable of receiving additional information regarding the same. The device maintains an inventory of the goods and will provide a display or hard copy of that inventory. In addition to maintaining inventories, the device may be programed to include information regarding the interaction of consumables with medications to alert the user to possible adverse reactions between them. The device preferably includes equipment for scanning the symbologies commonly associated with consumer goods.
| 5
|
BACKGROUND OF INVENTION
[0001] Current U.S. Class:
514/23; 514/565; 514/275; 514/385; 514/386; 514/396; 514/557; 514/501; 514/553; 514/563; 514/564; 514/575; 514/631; 514/636; 514/646; 514/546; 514/547
[0003] International Class: 037/12; A61K 037/26; A61K 031/198,70,19,22
[0004] Field of Search: 514/23, 3, 565, 275, 385, 386, 396, 546, 547, 553, 554, 501, 563, 564, 575, 631, 636, 646, 557
[0005] References Cited [Referenced By]: U.S. Patent Documents:
4883786 November, 1989 Puricelli. 5270472 December, 1993 Taglialatela. 6080786 June, 2000 Santaniello. Foreign Patent Documents: 0 354 848 February, 1990 EP. 98 47857 October, 1998WO.
FIELD OF THE INVENTION
[0007] The present invention relates to the field of muscle stimulation and more particularly to enhancing the production of energy by utilizing methyl pyruvic acid (a methyl ester of pyruvic acid) and/or methyl pyruvate (methyl pyruvate is the ionized form of methyl pyruvic acid), which modulate the system for the purpose of increasing muscle energy production. This will allow for contractions and expansions in the muscles of mammals.
[0008] In the following text, the terms “methyl pyruvate, methyl pyruvate compounds, methyl pyruvic acid” are used interchangeably.
[0009] Cells require energy to survive and perform their physiological functions, and it is generally recognized that the only source of energy for cells is the glucose and oxygen delivered by the blood. There are two major components to the process by which cells utilize glucose and oxygen to produce energy. The first component entails anaerobic conversion of glucose to pyruvate, which releases a small amount of energy, and the second entails oxidative conversion of pyruvate to carbon dioxide and water with the release of a large amount of energy. Pyruvate is continuously manufactured in the living organism from glucose. The process by which glucose is converted to pyruvate involves a series of enzymatic reactions that occur anaerobically (in the absence of oxygen). This process is called “glycolysis”. A small amount of energy is generated in the glycolytic conversion of glucose to pyruvate, but a much larger amount of energy is generated in a subsequent more complicated series of reactions in which pyruvate is broken down to carbon dioxide and water. This process, which does require oxygen and is referred to as “oxidative respiration”, involves the stepwise metabolic breakdown of pyruvate by various enzymes of the Krebs tricarboxylic acid cycle and conversion of the products into high-energy molecules by electron transport chain reactions.
[0010] ATP, the energy source for the muscle contraction and expansion process is ultimately formed when adenosine diphosphate (ADP), adds another phosphate group to form ATP. ATP cannot be stored in tissues in excess of a very limited threshold. Therefore, for persons involved in strenuous physical activities, such as athletes, a constant source of ATP is vital in order to maintain muscle energy levels.
OTHER REFERENCES
[0000]
Howlett R A, Gonzalez NC, Wagner HE, Fu Z, Britton S L, Koch L G, Wagner P D. Genetic Models in Applied Physiology: Selected Contribution: Skeletal muscle capillarity and enzyme activity in rats selectively bred for running endurance. J Appl Physiol. 2003 April; 94(4):1682-8.
Henderson K K, Wagner H, Favret F, Britton SL, Koch L G, Wagner P D, Gonzalez N C. Determinants of maximal O(2) uptake in rats selectively bred for endurance running capacity. J Appl Physiol. 2002 October; 93(4):1265-74.
Hussain S O, Barbato J C, Koch L G, Mettig P J, Britton S L. function in rats selectively bred for low- and high-capacity running. Am J Physiol Regul Integr Comp Physiol. 2001 December; 281(6):R1787-91.
Greiwe J S, Hickner R C, Hansen P A, Racette S B, Chen M M, Holloszy JO. Effects of endurance exercise training on muscle glycogen accumulation in humans. J Appl Physiol. July; 87(1):222-6.
Kayser B, Hoppeler H, Desplanches D, Marconi C, Broers B, Cerretelli P. Muscle ultrastructure and biochemistry of lowland Tibetans. J Appl Physiol. 1996 July; 81(1):419-25.
Bussieres L M, Pflugfelder P W, Taylor A W, Noble E G, Kostuk W J. in skeletal muscle morphology and biochemistry after cardiac transplantation. Am J Cardiol. 1997 Mar. 1; 79(5): 630-4.
Roberts K C, Nixon C, Unthank J L, Lash J M. artery ligation stimulates capillary growth and limits training-induced increases in oxidative capacity in rats. Microcirculation. 1997 June; 4(2):253-60.
Sexton W L. Vascular adaptations in rat hindlimb skeletal muscle after voluntary running-wheel exercise. J Appl Physiol. 1995 July; 79(1):287-96.
McAllister R M, Reiter B L, Amann J F, Laughlin M H. Skeletal muscle biochemical adaptations to exercise training in miniature swine. J Appl Physiol. 1997 June; 82(6):1862-8.
S L, Rennie C D, Hamilton S J, Tarnopolsky. Changes in skeletal muscle in males and females following endurance training. Can J Physiol Pharmacol. 2001 May; 79(5):386-92.
A R, Spina R J, King D S, Rogers M A, Brown M, Nemeth P M, Holloszy J O. Skeletal muscle adaptations to endurance training in 60-70-yr-old men and women. J Appl Physiol. 1992 May; 72(5):1780-6.
N, Torres S H, Rivas M. Inactivity changed fiber type proportion and capillary supply in cat muscle. Comp Biochem Physiol A Physiol. 1997 June; 117(2):211-7.
Y. Shimegi S, Masuda K, Sakato H, Ohmori H, Katsuta S. Effects of different intensity endurance training on the capillary network in rat skeletal muscle. Int J Microcirc Clin Exp. 1997 March-April; 17(2):93-6.
D, Fraga C, Laughlin M H, Amann J F. Regional changes in capillary supply in skeletal muscle of high-intensity endurance-trained rats. J Appl Physiol. 1996 August; 81(2):619-26.
R H, Booth F W, Winder W W, Holloszy J O. Skeletal muscle respiratory capacity, endurance, and glycogen utilization. Am J Physiol. 1975 April; 228(4):1029-33.
M G, Costill D L, Kirwan J P, Fink W J, Dengel D R. Muscle fiber composition and respiratory capacity in triathletes. Int J Sports Med. 1987 December; 8(6):383-6.
J R, Coyle E F, Osbakken M. of heart failure on skeletal muscle in dogs. Am J Physiol. 1992 April; 262(4 Pt 2): H993-8.
M, Eriksson B O, Lonn L, Rundqvist B, Sunnerhagen K S, Swedberg K. Skeletal muscle characteristics, muscle strength and thigh muscle area in patients before and after cardiac transplantation. Eur J Heart Fail. 2001 January; 3(1): 59-67.
R T, Hogan M C, Stary C, Bebout D E, Mathieu-Costello O, Wagner P D. Structural basis of muscle O(2) diffusing capacity: evidence from muscle function in situ. J Appl Physiol. 2000 February; 88(2):560-6.
Goreham C, Green H J, Ball-Burnett M, Ranney D. High-resistance training and muscle metabolism during prolonged exercise. Am J Physiol. 1999 March; 276(3 Pt 1):E489-96.
W L, Laughlin M H. Influence of endurance exercise training on distribution of vascular adaptations in rat skeletal muscle. Am J Physiol. 1994 February; 266(2 Pt 2):H483-90.
D R, Gregorevic P, Warmington S A, Williams D A, Lynch G S. Endurance training adaptations modulate the redox-force relationship of rat isolated slow-twitch skeletal muscles. Clin Exp Pharmacol Physiol. 2003 January-February; 30(1-2): 77-81.
A X, Brunet A, Guezennec C Y, Monod H. Skeletal muscle changes after endurance training at high altitude. J Appl Physiol. 1991 December; 71(6):2114-21.
R J, Chi M M, Hopkins M G, Nemeth P M, Lowry O H, Holloszy J O. Mitochondrial enzymes increase in muscle in response to 7-10 days of cycle exercise. J Appl Physiol. 1996 June; 80(6):2250-4.
Coggan A R, Spina R J, Rogers M A, King D S, Brown M, Nemeth P M, Holloszy J O. Histochemical enzymatic characteristics of skeletal muscle in master athletes. J Appl Physiol. 1990 May; 68(5):1896-901.
J S, Bruce C R, Spriet L L, Hawley J A. Interaction of diet and training on endurance performance in rats. Exp Physiol. 2001 July; 86(4):499-508.
Sumida K D, Donovan C M. Endurance training fails to inhibit skeletal muscle glucose uptake during exercise. J Appl Physiol. 1994 May; 76(5):1876-81.
Sullivan M J, Green H J, Cobb F R. Skeletal muscle biochemistry and histology in ambulatory patients with long-term heart failure. Circulation. 1990 February; 81(2):518-27.
D M, Coyle E, Coggan A, Beltz J, Ferraro N, Montain S, Wilson J R. Contribution of intrinsic skeletal muscle changes to 31P NMR skeletal muscle metabolic abnormalities in patients with chronic heart failure. Circulation. 1989 November; 80(5):1338-46.
M, Nakano H, Higaki Y, Nakamura T, Katsuta S, Kumagai S. Increased wheel-running activity in the genetically skeletal muscle fast-twitch fiber-dominant rats. J Appl Physiol. 2003 January; 94(1):185-92.
D L, Fink W J, Getchell L H, Ivy J L, Witzmann F A. Lipid metabolism in skeletal muscle of endurance-trained males and females. J Appl Physiol. 1979 October; 47(4):787-91.
Coggan A R, Spina R J, Kohrt W M, Holloszy J O. Effect of prolonged exercise on muscle citrate concentration before and after endurance training in men. Am J Physiol. 1993 February; 264(2 Pt 1):E215-20.
Snyder G K. Capillary growth in chick skeletal muscle with normal maturation and hypertrophy. Respir Physiol. 1995 December; 102(2-3):293-301.
Weston A R, Wilson G R, Noakes T D, Myburgh K H. Skeletal muscle buffering capacity is higher in the superficial vastus than in the soleus of spontaneously running rats. Acta Physiol Scand. 1996 June; 157(2):211-6.
Torgan C E, Brozinick J T Jr, Kastello G M, Ivy J L Muscle morphological and biochemical adaptations to training in obese Zucker rats. J Appl Physiol. 1989 November; 67(5):1807-13.
Sexton W L, Poole D C, Mathieu-Costello O. Microcirculatory structure-function relationships in skeletal muscle of diabetic rats. Am J Physiol. 1994 April; 266(4 Pt 2):H1502-11.
Parsons D, Musch T I, Moore R L, Haidet G C, Ordway G A. Dynamic exercise training in foxhounds. II. Analysis of skeletal muscle. J Appl Physiol. 1985 July; 59(1):190-7.
Celsing F, Blomstrand E, Melichna J, Terrados N, Clausen N, Lins P E, Jansson E. Effect of hyperthyroidism on fibre-type composition, fibre area, glycogen content and enzyme activity in human skeletal muscle. Clin Physiol. 1986 April; 6(2):171-81.
Coggan A R, Abduljalil A M, Swanson S C, Earle M S, Farris J W, Mendenhall L A, Robitaille P M. Muscle metabolism during exercise in young and older untrained and endurance-trained men. J Appl Physiol. 1993 November; 75(5):2125-33.
Leon-Velarde F, Sanchez J, Bigard A X, Brunet A, Lesty C, Monge C. High altitude tissue adaptation in Andean coots: capillarity, fibre area, fibre type and enzymatic activities of skeletal muscle. J Comp Physiol [B]. 1993; 163(1):52-8.
Maxwell L C, White T P, Faulkner J A. Oxidative capacity, blood flow, and capillarity of skeletal muscles. J Appl Physiol. 1980 October; 49(4):627-33.
Foster C, Costill D L, Daniels J T, Fink W J. Skeletal muscle enzyme activity, fiber composition and VO2 max in relation to distance running performance. Eur J Appl Physiol Occup Physiol. 1978 Aug. 15; 39(2):73-80.
Mitchell M L, Byrnes W C, Mazzeo R S. A comparison of skeletal muscle morphology with training between young and old Fischer 344 rats. Mech Ageing Dev. 1991 Apr. 1; 58(1):21-35.
Bigard A X, Brunet A, Guezennec C Y, Monod H. Effects of chronic hypoxia and endurance training on muscle capillarity in rats. Pflugers Arch. 1991 October; 419(3-4):225-9.
Thomas D P, Jenkins R R. Effects of beta 1—vs. beta 1—beta 2-blockade on training adaptations in rat skeletal muscle. J Appl Physiol. 1986 May; 60(5):1722-6.
Duscha B D, Annex B H, Keteyian S J, Green H J, Sullivan M J, Samsa G P, Brawner C A, Schachat F H, Kraus W E. Differences in skeletal muscle between men and women with chronic heart failure. J Appl Physiol. 2001 January; 90(1):280-6.
Bangsbo J, Michalsik L, Petersen A. Accumulated O2 deficit during intense exercise and muscle characteristics of elite athletes. Int J Sports Med. 1993 May; 14(4):207-13.
Tanaka T, Ohira Y, Danda M, Hatta H, Nishi I. Improved fatigue resistance not associated with maximum oxygen consumption in creatine-depleted rats. J Appl Physiol. 1997 June; 82(6):1911-7.
Hammeren J, Powers S, Lawler J, Criswell D, Martin D, Lowenthal D, Pollock M. skeletal muscle oxidative and antioxidant enzyme activity in senescent rats. Int J Sports Med. 1992 July; 13(5): 412-6.
MacDougall J D, Hicks A L, MacDonald J R, McKelvie R S, Green H J, Smith K M. Muscle performance and enzymatic adaptations to sprint interval training. J Appl Physiol. 1998 June; 84(6):2138-42.
Schluter J M, Fitts RH. Shortening velocity and ATPase activity of rat skeletal muscle fibers: effects of endurance exercise training. Am J Physiol. 1994 June; 266(6 Pt 1):C1699-73.
Suter E, Hoppeler H, Claassen H, Billeter R, Aebi U, Horber F, Jaeger P, Marti B. Ultrastructural modification of human skeletal muscle tissue with 6-month moderate-intensity exercise training. Int J Sports Med. 1995 April; 16(3):160-6.
Russell J A, Kindig C A, Behnke B J, Poole DC, Musch T I. Effects of aging on capillary geometry and hemodynamics in rat spinotrapezius muscle. Am J Physiol Heart Circ Physiol. 2003 Mar. 20.
Magnusson G, Kaijser L, Rong H, Isberg B, Sylven C, Saltin B. capacity in heart failure patients: relative importance of heart and skeletal muscle. Clin Physiol. 1996 March; 16(2):183-95.
Frandsen U, Hoffner L, Betak A, Saltin B, Bangsbo J, Hellsten Y. training does not alter the level of neuronal nitric oxide synthase in human skeletal muscle. J Appl Physiol. 2000 September; 89(3):1033-8.
Chati Z, Michel C, Escanye J M, Mertes P M, Ribuot C, Canet D, Zannad F. Skeletal muscle beta-adrenoreceptors and phosphate metabolism abnormalities in heart failure in rats. Am J Physiol. 1996 November; 271(5 Pt 2):H1739-45.
Snyder G K. Capillarity and diffusion distances in skeletal muscles in birds. J Comp Physiol [B]. 1990; 160(5):583-91.
Lambert M I, Van Zyl C, Jaunky R, Lambert E V, Noakes T D. Tests of running performance do not predict subsequent spontaneous running in rats. Physiol Behav. 1996 July; 60(1):171-6.
Tikkanen H O, Naveri H K, Harkonen M H. Alteration of regulatory enzyme activities in fast-twitch and slow-twitch muscles and muscle fibres in low-intensity endurance-trained rats. Eur J Appl Physiol Occup Physiol. 1995; 70(4):281-7.
Moore R L, Gollnick P D. Response of ventilatory muscles of the rat to endurance training. Pflugers Arch. 1982 January; 392(3):268-71.
Hickson R C, Heusner W W, Van Huss W D. Skeletal muscle enzyme alterations after sprint and endurance training. J Appl Physiol. 1976 June; 40(6):868-71.
Hickner R C, Fisher J S, Hansen PA, Racette SB, Mier CM, Turner M J, Holloszy J O. Muscle glycogen accumulation after endurance exercise in trained and untrained individuals. J Appl Physiol. 1997 September; 83(3):897-903.
Zhan W Z, Swallow J G, Garland T Jr, Proctor D N, Carter P A, Sieck G C. Effects of genetic selection and voluntary activity on the medial gastrocnemius muscle in house mice. J Appl Physiol. 1999 December; 87(6):2326-33.
Snyder G K, Wilcox E E, Burnham E W. Effects of hypoxia on muscle capillarity in rats. Respir Physiol. 1985 October; 62(1):135-40.
Coyle E F, Coggan A R, Hopper M K, Walters T J. Determinants of endurance in well-trained cyclists. J Appl Physiol. 1988 June; 64(6):2622-30.
Baldwin K M, Cooke D A, Cheadle W G. Time course adaptations in cardiac and skeletal muscle to different running programs. J Appl Physiol. 1977 February; 42(2):267-72.
Howlett R A, Heigenhauser G J, Hultman E, Hollidge-Horvat M G, Spriet L L. Effects of dichloroacetate infusion on human skeletal muscle metabolism at the onset of exercise. Am J Physiol. 1999 July; 277(1 Pt 1): E18-25.
Jansson E, Sylven C. of key enzymes in the energy metabolism of human myocardial and skeletal muscle. Clin Physiol. 1986 October; 6(5):465-71.
Baldwin K M, Winder W W, Holloszy J O. Adaptation of actomyosin ATPase in different types of muscle to endurance exercise. Am J Physiol. 1975 August; 229(2):422-6.
Bigard A X, Brunet A, Serrurier B, Guezennec CY, Monod H. of endurance training at high altitude on diaphragm muscle properties. Pflugers Arch. 1992 December; 422(3):239-44.
Kalliokoski K K, Kuusela T A, Laaksonen M S, Knuuti J, Nuutila P. Muscle fractal vascular branching pattern and microvascular perfusion heterogeneity in endurance-trained and untrained men. J Physiol. 2003 Jan. 15; 546(Pt 2):529-35.
Saltin B, Kim C K, Terrados N, Larsen H, Svedenhag J, Rolf C J. Morphology, enzyme activities and buffer capacity in leg muscles of Kenyan and Scandinavian runners. Scand J Med Sci Sports. 1995 August; 5(4):222-30.
Maltais F, LeBlanc P, Simard C, Jobin J, Berube C, Bruneau J, Carrier L, Belleau R. Skeletal muscle adaptation to endurance training in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 1996 August; 154(2 Pt 1):442-7.
Green H J, Jones S, Ball-Burnett M E, Smith D, Livesey J, Farrance B W. Early muscular and metabolic adaptations to prolonged exercise training in humans. J Appl Physiol. May; 70(5):2032-8.
Snyder G K, Farrelly C, Coelho J R. Adaptations in skeletal muscle capillarity following changes in oxygen supply and changes in oxygen demands. Eur J Appl Physiol Occup Physiol. 1992; 65(2):158-63.
Green H, Roy B, Grant S, Otto C, Pipe A, McKenzie D, Johnson M. Human skeletal muscle exercise metabolism following an expedition to mount denali. Am J Physiol Regul Integr Comp Physiol. 2000 November; 279(5):R1872-9.
Gosselin L E, Betlach M, Vailas A C, Thomas D P. Training-induced alterations in young and senescent rat diaphragm muscle. J Appl Physiol. 1992 April; 72(4):1506-11.
Wang X N, Williams T J, McKenna M J, Li J L, Fraser S F, Side E A, Snell G I, Walters E H, Carey M F. Skeletal muscle oxidative capacity, fiber type, and metabolites after lung transplantation. Am J Respir Crit Care Med. 1999 July; 160(1):57-63.
Riedy M, Moore R L, Gollnick P D. Adaptive response of hypertrophied skeletal muscle to endurance training. J Appl Physiol. 1985 July; 59(1): 127-31.
Miller W C, Bryce G R, Conlee R K. Adaptations to a high-fat diet that increase exercise endurance in male rats. J Appl Physiol. 1984 January; 56(1):78-83.
W M, Costill D L, Fink W J, Hagerman F C, Armstrong L E, Murray T F. Effect of a 42.2-km footrace and subsequent rest or exercise on muscle glycogen and enzymes. J Appl Physiol. 1983 October; 55(4):1219-24.
Baldwin K M, Hooker A M, Herrick R E, Schrader L F. Respiratory capacity and glycogen depletion in thyroid-deficient muscle. J Appl Physiol. 1980 July; 49(1): 102-6.
Willis W T, Brooks G A, Henderson S A, Dallman P R. Effects of iron deficiency and training on mitochondrial enzymes in skeletal muscle. J Appl Physiol. 1987 June; 62(6):2442-6.
McConell G, McCoy M, Proietto J, Hargreaves M. Skeletal muscle GLUT-4 and glucose uptake during exercise in humans. J Appl Physiol. 1994 September; 77(3):1565-8.
Nakatani A, Han DH, Hansen PA, Nolte L A, Host H H, Hickner R C, Holloszy J O. Effect of endurance exercise training on muscle glycogen supercompensation in rats. J Appl Physiol. 1997 February; 82(2):711-5.
R M, Terjung R L. Training-induced muscle adaptations: increased performance and oxygen consumption. J Appl Physiol. 1991 April; 70(4):1569-74.
A T, Foley J M, Meyer R A. Linear dependence of muscle phosphocreatine kinetics on oxidative capacity. Am J Physiol. 1997 February; 272(2 Pt 1):C501-10.
S, Powers S K, Lawler J, Criswell D, Dodd S, Edwards W. Endurance training-induced increases in expiratory muscle oxidative capacity. Med Sci Sports Exerc. 1992 May; 24(5):551-5.
P A, Waldmann M L, Meyer W L, Brown K A, Poehlman E T, Pendlebury W W, Leslie K O, Gray P R, Lew R R, LeWinter M M. Skeletal muscle and cardiovascular adaptations to exercise conditioning in older coronary patients. Circulation. 1996 Aug. 1; 94(3):323-30.
V P, Gettelman G J, Widrick J J, Fitts RH. Substrate and enzyme profile of fast and slow skeletal muscle fibers in rhesus monkeys. J Appl Physiol. 1999 January; 86(1):335-40.
P, Garland T Jr, Swallow J G, Guderley H. Effects of voluntary activity and genetic selection on muscle metabolic capacities in house mice Mus domesticus. J Appl Physiol. 2000 October; 89(4):1608-16.
J L, Serrano A L, Henckel P. Activities of selected aerobic and anaerobic enzymes in the gluteus mediusmuscle of endurance horses with different performance recordsVet Rec. 1995 Aug. 19; 137(8):187-92.
Apple F S, Rogers M A. Skeletal muscle lactate dehydrogenase isozyme alterations in men and women marathon runners. J Appl Physiol. 1986 August; 61(2):477-81.
P, Torres A, Morcuende J A, Garcia-Castellano J M, Calbet J A, Sarrat R. Effect of endurance running on cardiac and skeletal muscle in rats. Histol Histopathol. 2001 January; 16(1):29-35.
Soar P K, Davies C T, Fentem P H, Newsholme E A. effect of endurance-training on the maximum activities of hexokinase, 6-phosphofructokinase, citrate synthase, and oxoglutarate dehydrogenase in red and white muscles of the rat. Biosci Rep. 1983 September; 3(9):831-5.
Goodpaster B H, He J, Watkins S, Kelley D E Skeletal muscle lipid content and insulin resistance: evidence for a paradox in endurance-trained athletes. J Clin Endocrinol Metab. 2001 December; 86(12):5755-61.
E, Sillau A H, Banchero N. Changes in the capillarity of skeletal muscle in the growing rat. Pflugers Arch. 1979 Jun. 12; 380(2): 153-8.
J P, Costill D L, Flynn M G, Neufer P D, Fink W J, Morse W M. Effects of increased training volume on the oxidative capacity, glycogen content and tension development of rat skeletal muscle. Int J Sports Med. 1990 December; 11(6):479-83.
Wallberg-Henriksson H, Gunnarsson R, Henriksson J, Ostman J, Wahren J. Influence of physical training on form ation of muscle capillaries in type I diabetes. Diabetes. 1984 September; 33(9):851-7.
SUMMARY OF INVENTION
[0110] The present invention relates to the field of muscle stimulation and more particularly to enhancing the production of the energy by utilizing methyl pyruvate compounds, which modulate the system. This modulation will allow contractions and expansions in the muscles of mammals. A preferred mode of use involves co-administration of a methyl pyruvate salt along with one or more agents that promote energy. Typical dosages of methyl pyruvate compounds will depend on factors such as size, age, health and fitness level along with the duration and type of physical activity.
[0111] The present invention further pertains to methods of use of methyl pyruvate compounds in combination with vitamins, coenzymes, mineral substances, amino acids, herbs, antioxidants and creatine compounds, which act on the muscle for enhancing energy production and thus performance.
[0112] Creatine exerts various effects upon entering the muscle. It is these effects that elicit improvements in exercise performance and may be responsible for the improvements of muscle function and energy metabolism seen under certain disease conditions. Several mechanisms have been proposed to explain the increased exercise performance seen after acute and chronic Cr intake. Adenosine triphosphate (ATP) concentrations maintain physiological processes and protect tissue from hypoxia-induced damage. Cr is involved in ATP production through its involvement in PCr energy system. This system can serve as a temporal and spatial energy buffer as well as a pH buffer. As a spatial energy buffer, Cr and PCr are involved in the shuttling of ATP from the inner mitochondria into the cytosol. In the reversible reaction catalyzed by creatine kinase, Cr and ATP form PCr and adenosine diphosphate (ADP). It is this reaction that can serve as both a temporal energy buffer and pH buffer. The formation of the polar PCr “locks” Cr in the muscle and maintains the retention of Cr because the charge prevents partitioning through biological membranes. At times during low pH (during exercise when lactic acid accumulates), the reaction will favor the generation of ATP. Conversely, during recovery periods (e.g., periods of rest between exercise sets) where ATP is being generated aerobically, the reaction will proceed and increase PCr levels. This energy and pH buffer is one mechanism by which Cr works to increase exercise performance.
[0113] The Creatine compounds which can be used in the present method include (1) creatine, creatine phosphate and analogs of these compounds which can act as substrates or substrate analogs for creatine kinase; (2) bisubstrate inhibitors of creatine kinase comprising covalently linked structural analogs of adenosine triphosphate (ATP) and creatine; (3) creatine analogs which can act as reversible or irreversible inhibitors of creatine kinase; and (4) N-phosphorocreatine analogs bearing non-transferable moieties which mimic the N-phosphoryl group.
DETAILED DESCRIPTION
[0114] This invention entails a use of methyl pyruvate for enhancing muscle energy production. Methyl pyruvate is the ionized form of methyl pyruvic acid (CH3C(O)CO2CH3). At physiologic pH, the hydrogen proton dissociates from the carboxylic acid group, thereby generating the methyl pyruvate anion. When used as a pharmaceutical or dietary supplement, this anion can be formulated as a salt, using a monovalent or divalent cation such as sodium, potassium, magnesium, or calcium.
[0115] Pancreatic beta-cell as a model: The energy requirements of most cells supplied with glucose are fulfilled by glycolytic and oxidative metabolism, yielding ATP. When cytosolic and mitochondrial contents in ATP, ADP and AMP were measured in islets incubated for 45 min at increasing concentrations of D-glucose and then exposed for 20 s to digitonin. The latter treatment failed to affect the total islet ATP/ADP ratio and adenylate charge. D-Glucose caused a much greater increase in cytosolic than mitochondrial ATP/ADP ratio. In the cytosol, a sigmoidal pattern characterized the changes in ATP/ADP ratio at increasing concentrations of D-glucose. These findings are compatible with the view that cytosolic ATP participates in the coupling of metabolic to ionic events in the process of nutrient-induced insulin release.
[0116] To gain insight into the regulation of pancreatic beta-cell mitochondrial metabolism, the direct effects on respiration of different mitochondrial substrates, variations in the ATP/ADP ratio and free Ca2+were examined using isolated mitochondria and permeabilized clonal pancreatic beta-cells (HIT). Respiration from pyruvate was high and not influenced by Ca2+in State 3 or under various redox states and fixed values of the ATP/ADP ratio; nevertheless, high Ca2+elevated pyridine nucleotide fluorescence, indicating activation of pyruvate dehydrogenase by Ca2+. Furthermore, in the presence of pyruvate, elevated Ca2+ stimulated CO2 production from pyruvate, increased citrate production and efflux from the mitochondria and inhibited CO2 production from palmitate. The latter observation suggests that beta-cell fatty acid oxidation is not regulated exclusively by malonyl-CoA but also by the mitochondrial redox state.
alpha-Glycerophosphate (alpha-GP) oxidation is Ca(2+)-dependent with a half-maximal rate observed at around 300 nM Ca2+. It was recently demonstrated that increases in respiration precede increases in Ca2+ in glucose-stimulated clonal pancreatic beta-cells (HIT), indicating that Ca2+ is not responsible for the initial stimulation of respiration. It is suggested that respiration is stimulated by increased substrate (alpha-GP and pyruvate) supply together with oscillatory increases in ADP.
[0118] The rise in Ca2+, which in itself may not significantly increase net respiration, could have the important functions of (1) activating the alpha-GP shuttle, to maintain an oxidized cytosol and high glycolytic flux; (2) activating pyruvate dehydrogenase, and indirectly pyruvate carboxylase, to sustain production of citrate and hence the putative signal coupling factors, malonyl-CoA and acyl-CoA; (3) increasing mitochondrial redox state to implement the switch from fatty acid to pyruvate oxidation.
[0119] Glucose-stimulated increases in mitochondrial metabolism are generally thought to be important for the activation of insulin secretion. Pyruvate dehydrogenase (PDH) is a key regulatory enzyme, believed to govern the rate of pyruvate entry into the citrate cycle. It has been shown that elevated glucose concentrations (16 or 30 vs 3 mM) cause an increase in PDH activity in both isolated rat islets, and in a clonal beta-cell line (MIN6). However, increases in PDH activity elicited with either dichloroacetate, or by adenoviral expression of the catalytic subunit of pyruvate dehydrogenase phosphatase, were without effect on glucose-induced increases in mitochondrial pyridine nucleotide levels, or cytosolic ATP concentration, in MIN6 cells, and insulin secretion from isolated rat islets. Similarly, the above parameters were unaffected by blockade of the glucose-induced increase in PDH activity by adenovirus-mediated over-expression of PDH kinase (PDK). Thus, activation of the PDH complex plays an unexpectedly minor role in stimulating glucose metabolism and in triggering insulin release.
[0120] In pancreatic beta-cells, a rise in cytosolic ATP is also a critical signaling event, coupling closure of ATP-sensitive K+ channels (KATP) to insulin secretion via depolarization-driven increases in intracellular Ca2+. Glycolytic but not Krebs cycle metabolism of glucose is critically involved in this signaling process. While inhibitors of glycolysis suppressed glucose-stimulated insulin secretion, blockers of pyruvate transport or Krebs cycle enzymes were without effect. While pyruvate was metabolized in islets to the same extent as glucose, it produced no stimulation of insulin secretion and did not block KATP.
[0121] In pancreatic beta-cells, methyl pyruvate is a potent secretagogue and is used to study stimulus-secretion coupling. MP stimulated insulin secretion in the absence of glucose, with maximal effect at 5 mM. MP depolarized the beta-cell in a concentration-dependent manner (5-20 mM). Pyruvate failed to initiate insulin release (5-20 mM) or to depolarize the membrane potential. ATP production in isolated beta-cell mitochondria was detected as accumulation of ATP in the medium during incubation in the presence of malate or glutamate in combination with pyruvate or MP. ATP production by MP and glutamate was higher than that induced by pyruvate/glutamate. Pyruvate (5 mM) or MP (5 mM) had no effect on the ATP/ADP ratio in whole islets, whereas glucose (20 mM) significantly increased the whole islet ATP/ADP ratio.
[0122] In contrast with pyruvate, which barely stimulates insulin secretion, methyl pyruvate was suggested to act as an effective mitochondrial substrate. Methyl pyruvate elicited electrical activity in the presence of 0.5 mM glucose, in contrast with pyruvate. Accordingly, methyl pyruvate increased the cytosolic free Ca(2+) concentration after an initial decrease, similar to glucose. However, in contrast with glucose, methyl pyruvate even slightly decreased NAD(P)H autofluorescence and did not influence ATP production or the ATP/ADP ratio. Therefore, MP-induced beta-cell membrane depolarization or insulin release does not relate directly to mitochondrial ATP production.
[0123] The finding that methyl pyruvate directly inhibited a cation current across the inner membrane of Jurkat T-lymphocyte mitochondria suggests that this metabolite may increase ATP production in beta-cells by activating the respiratory chains without providing reduction equivalents. This mechanism may account for a slight and transient increase in ATP production. Furthermore methyl pyruvate inhibited the K(ATP) current measured in the standard whole-cell configuration. Accordingly, single-channel currents in inside-out patches were blocked by methyl pyruvate. Therefore, the inhibition of K(ATP) channels, and not activation of metabolism, mediates the induction of electrical activity in pancreatic beta-cells by methyl pyruvate.
[0124] As a membrane-permeant analog, methyl pyruvate, produced a block of KATP, a sustained rise in [Ca2+], and an increase in insulin secretion 6-fold the magnitude of that induced by glucose. This indicates that ATP derived from mitochondrial pyruvate metabolism does not substantially contribute to the regulation of KATP responses to a glucose challenge. Supporting the notion of sub-compartmentation of ATP within the beta-cell. Supra-normal stimulation of the Krebs cycle by methyl pyruvate can, however, overwhelm intracellular partitioning of ATP and thereby drive insulin secretion.
[0125] The metabolism of methyl pyruvate was compared to that of pyruvate in isolated rat pancreatic islets. Methyl pyruvate was found to be more efficient than pyruvate in supporting the intra-mitochondrial conversion of pyruvate metabolites to amino acids, inhibiting D-[5-3H]glucose utilization, maintaining a high ratio between D-[3,4-14C] glucose or D-[6-14C]glucose oxidation and D-[5-3H]glucose utilization, inhibiting the intra-mitochondrial conversion of glucose-derived 2-keto acids to their corresponding amino acids, and augmenting 14CO2 output from islets prelabeled with L-[U-14C] glutamine. Methyl pyruvate also apparently caused a more marked mitochondrial alkalinization than pyruvate, as judged from comparisons of pH measurements based on the use of either a fluorescein probe or 14C-labeled 5,5-dimethyl-oxazolidine-2,4-dione.
[0126] Inversely, pyruvate was more efficient than methyl pyruvate in increasing lactate output and generating L-alanine. These converging findings indicate that, by comparison with exogenous pyruvate, its methyl ester is preferentially metabolized in the mitochondrial, rather than cytosolic, domain of islet cells. It is proposed that both the positive and the negative components of methyl pyruvate insulinotropic action are linked to changes in the net generation of reducing equivalents, ATP and H+.
[0127] Methyl pyruvate was found to exert a dual effect on insulin release from isolated rat pancreatic islets. A positive insulinotropic action prevailed at low concentrations of D-glucose, in the 2.8 to 8.3 mM range, and at concentrations of the ester not exceeding 10.0 mM. It displayed features typical of a process of nutrient-stimulated insulin release, such as decreased K+ conductance, enhanced Ca2+ influx, and stimulation of proinsulin biosynthesis. A negative insulinotropic action of methyl pyruvate was also observed, however, at a high concentration of D-glucose (16.7 mM) and/or at a high concentration of the methyl ester (20.0 mM). It was apparently not attributable to any adverse effect of methyl pyruvate on ATP generation, but might be due to hyperpolarization of the plasma membrane. The ionic determinant(s) of the latter change was not identified. The dual effect of methyl pyruvate probably accounts for an unusual time course of the secretory response, including a dramatic and paradoxical stimulation of insulin release upon removal of the ester.
[0128] Pancreatic beta-cell metabolism was followed during glucose and pyruvate stimulation of pancreatic islets using quantitative two-photon NAD(P)H imaging. The observed redox changes, spatially separated between the cytoplasm and mitochondria, were compared with whole islet insulin secretion. As expected, both NAD(P)H and insulin secretion showed sustained increases in response to glucose stimulation. In contrast, pyruvate caused a much lower NAD(P)H response and did not generate insulin secretion. Low pyruvate concentrations decreased cytoplasmic NAD(P)H without affecting mitochondrial NAD(P)H, whereas higher concentrations increased cytoplasmic and mitochondrial levels. However, the pyruvate-stimulated mitochondrial increase was transient and equilibrated to near-base-line levels. Inhibitors of the mitochondrial pyruvate-transporter and malate-aspartate shuttle were utilized to resolve the glucose- and pyruvate-stimulated NAD(P)H response mechanisms. These data showed that glucose-stimulated mitochondrial NAD(P)H and insulin secretion are independent of pyruvate transport but dependent on NAD(P)H shuttling. In contrast, the pyruvate-stimulated cytoplasmic NAD(P)H response was enhanced by both inhibitors. Surprisingly the malate-aspartate shuttle inhibitor enabled pyruvate-stimulated insulin secretion. These data support a model in which glycolysis plays a dominant role in glucose-stimulated insulin secretion. Based on these data, it was proposed as a mechanism for glucose-stimulated insulin secretion that includes allosteric inhibition of tricarboxylic acid cycle enzymes and pH dependence of mitochondrial pyruvate transport.
[0129] Pyridine dinucleotides (NAD and NADP) are ubiquitous cofactors involved in hundreds of redox reactions essential for the energy transduction and metabolism in all living cells. NAD is an indispensable redox cofactor in all organisms. Most of the genes required for NAD biosynthesis in various species are known. In addition, NAD also serves as a substrate for ADP-ribosylation of a number of nuclear proteins, for silent information regulator 2 (Sir2)-like histone deacetylase that is involved in gene silencing regulation, and for cyclic ADP ribose (cADPR)-dependent Ca(2+) signaling. Pyridine nucleotide adenylyltransferase (PNAT) is an indispensable central enzyme in the NAD biosynthesis pathways catalyzing the condensation of pyridine mononucleotide (NMN or NaMN) with the AMP moiety of ATP to form NAD (or NaAD).
[0130] 1. In isolated pancreatic islets, pyruvate causes a shift to the left of the sigmoidal curve relating the rate of insulin release to the ambient glucose concentration. The magnitude of this effect is related to the concentration of pyruvate (5—90 mM) and, at a 30 mM concentration, is equivalent to that evoked by 2 mM-glucose.
[0131] 2. In the presence of glucose 8 mM), the secretory response to pyruvate is an immediate process, displaying a biphasic pattern.
[0132] 3. The insulinotropic action of pyruvate coincides with an inhibition of 45Ca efflux and a stimulation of 45Ca net uptake. The relationship between 45Ca uptake and insulin release displays its usual pattern in the presence of pyruvate.
4. Exogenous pyruvate rapidly accumulates in the islets in amounts close to those derived from the metabolism of glucose. The oxidation of [2-14C]pyruvate represents 64% of the rate of [1-14C]pyruvate decarboxylation and, at a 30 mM concentration, is comparable with that of 8 mM-[U-14C]glucose.
[0134] 5. When corrected for the conversion of pyruvate into lactate, the oxidation of 30 mM-pyruvate corresponds to a net generation of about 314 pmol of reducing equivalents/120 min per islet.
[0135] 6. Pyruvate does not affect the rate of glycolysis, but inhibits the oxidation of glucose. Glucose does not affect pyruvate oxidation.
[0136] 7. Pyruvate (30 mM) does not affect the concentration of ATP, ADP and AMP in the islet cells.
[0137] 8. Pyruvate (30 mM) increases the concentration of reduced nicotinamide nucleotides in the presence but not in the absence of glucose. A close correlation is seen between the concentration of reduced nicotinamide nucleotides and the net uptake of 45 Ca.
[0138] 9. Pyruvate, like glucose, modestly stimulates lipogenesis.
[0139] 10. Pyruvate, in contrast with glucose, markedly inhibits the oxidation of endogenous nutrients. The latter effect accounts for the apparent discrepancy between the rate of pyruvate oxidation and the magnitude of its insulinotropic action.
[0140] 11. It is concluded that the effect of pyruvate to stimulate insulin release depends on its ability to increase the concentration of reduced nicotinamide nucleotides in the islet cells.
[0141] Glucose-stimulated insulin secretion is a multi-step process dependent on cell metabolic flux. Previous studies on intact pancreatic islets used two-photon NAD(P)H imaging as a quantitative measure of the combined redox signal from NADH and NADPH (referred to as NAD(P)H). These studies showed that pyruvate, a non-secretagogue, enters—cells and causes a transient rise in NAD(P)H. To further characterize the metabolic fate of pyruvate, a one-photon flavoprotein microscopy has been developed as a simultaneous assay of lipoamide dehydrogenase (LipDH) autofluorescence. This flavoprotein is in direct equilibrium with mitochondrial NADH. Using this method, the glucose-dose response is consistent with an increase in both NADH and NADPH. In contrast, the transient rise in NAD(P)H observed with pyruvate stimulation is not accompanied by a significant change in LipDH, which indicates that pyruvate raises cellular NADPH without raising NADH. In comparison, methyl pyruvate stimulated a robust NADH and NADPH response. These data provide new evidence that exogenous pyruvate does not induce a significant rise in mitochondrial NADH. This inability likely results in its failure to produce the ATP necessary for stimulated secretion of insulin. Overall, these data are consistent with either restricted PDH dependent metabolism or a buffering of the NADH response by other metabolic mechanisms.
[0142] Glucose metabolism in glycolysis and in mitochondria is pivotal to glucose-induced insulin secretion from pancreatic beta cells. One or more factors derived from glycolysis other than pyruvate appear to be required for the generation of mitochondrial signals that lead to insulin secretion. The electrons of the glycolysis-derived reduced form of nicotinamide adenine dinucleotide (NADH) are transferred to mitochondria through the NADH shuttle system. By abolishing the NADH shuttle function, glucose-induced increases in NADH autofluorescence, mitochondrial membrane potential, and adenosine triphosphate content were reduced and glucose-induced insulin secretion was abrogated. The NADH shuttle evidently couples glycolysis with activation of mitochondrial energy metabolism to trigger insulin secretion.
[0143] To determine the role of the NADH shuttle system composed of the glycerol phosphate shuttle and malate-aspartate shuttle in glucose-induced insulin secretion from pancreatic beta cells, mice which lack mitochondrial glycerol-3 phosphate dehydrogenase mGPDH), a rate-limiting enzyme of the glycerol phosphate shuttle were used. When both shuttles were halted in mGPDH-deficient islets treated with aminooxyacetate, an inhibitor of the malate-aspartate shuttle, glucose-induced insulin secretion was almost completely abrogated. Under these conditions, although the flux of glycolysis and supply of glucose-derived pyruvate into mitochondria were unaffected, glucose-induced increases in NAD(P)H autofluorescence, mitochondrial membrane potential, Ca2+entry into mitochondria, and ATP content were severely attenuated. This study provides the first direct evidence that the NADH shuttle system is essential for coupling glycolysis with the activation of mitochondrial energy metabolism to trigger glucose-induced insulin secretion and thus revises the classical model for the metabolic signals of glucose-induced insulin secretion.
[0144] Incubation of porcine carotid arteries with 0. 4 mmol amino-oxyacetic acid an inhibitor of glutamate-oxaloacetate transaminase and, hence the malate-aspartate shuttle, inhibited O2 consumption by 21%, decreased the content of phosphocreatine and inhibited activity of the tricarboxylic acid cycle. The rate of glycolysis and lactate production was increased but glucose oxidation was inhibited. These effects of amino-oxyacetic acid were accompanied by evidence of inhibition of the malate-aspartate shuttle and elevation in the cytoplasmic redox potential and NADH/NAD ratio as indicated by elevation of the concentration ratios of the lactate/pyruvate and glycerol-3-phosphate/dihydroxyacetone phosphate metabolite redox couples. Addition of the fatty acid octanoate normalized the adverse energetic effects of malate-aspartate shuttle inhibition. It is concluded that the malate-aspartate shuttle is a primary mode of clearance of NADH reducing equivalents from the cytoplasm in vascular smooth muscle. Glucose oxidation and lactate production are influenced by the activity of the shuttle. The results support the hypothesis that an increased cytoplasmic NADH redox potential impairs mitochondrial energy metabolism.
[0145] Beta-Methyleneaspartate, a specific inhibitor of aspartate aminotransferase (EC 2.6.1.1.), was used to investigate the role of the malate-aspartate shuttle in rat brain synaptosomes. Incubation of rat brain cytosol, “free” mitochondria, synaptosol, and synaptic mitochondria, with 2 mM beta-methyleneaspartate resulted in inhibition of aspartate aminotransferase by 69%, 67%, 49%, and 76%, respectively. The reconstituted malate-aspartate shuttle of “free” brain mitochondria was inhibited by a similar degree (53%).
[0146] As a consequence of the inhibition of the aspartate aminotransferase, and hence the malate-aspartate shuttle, the following changes were observed in synaptosomes: decreased glucose oxidation via the pyruvate dehydrogenase reaction and the tricarboxylic acid cycle; decreased acetylcholine synthesis; and an increase in the cytosolic redox state, as measured by the lactate/pyruvate ratio. The main reason for these changes can be attributed to decreased carbon flow through the tricarboxylic acid cycle (i.e., decreased formation of oxaloacetate), rather than as a direct consequence of changes in the NAD+/NADH ratio.
[0147] Aminooxyacetate, an inhibitor of pyridoxal-dependent enzymes, is routinely used to inhibit gamma-aminobutyrate metabolism. The bioenergetic effects of the inhibitor on guinea-pig cerebral cortical synaptosomes are investigated. It prevents the reoxidation of cytosolic NADH by the mitochondria by inhibiting the malate-aspartate shuttle, causing a 26 mV negative shift in the cytosolic NAD+/NADH redox potential, an increase in the lactate/pyruvate ratio and an inhibition of the ability of the mitochondria to utilize glycolytic pyruvate. The 3-hydroxybutyrate/acetoacetate ratio decreased significantly, indicating oxidation of the mitochondrial NAD+/NADH couple. The results are consistent with a predominant role of the malate-aspartate shuttle in the reoxidation of cytosolic NADH in isolated nerve terminals. Aminooxyacetate limits respiratory capacity and lowers mitochondrial membrane potential and synaptosomal ATP/ADP ratios to an extent similar to glucose deprivation.
[0148] Variations in the cytoplasmic redox potential (Eh) and NADH/NAD ratio as determined by the ratio of reduced to oxidized intracellular metabolite redox couples may affect mitochondrial energetics and alter the excitability and contractile reactivity of vascular smooth muscle. To test these hypotheses, the cytoplasmic redox state was experimentally manipulated by incubating porcine carotid artery strips in various substrates. The redox potentials of the metabolite couples [lactate]/[pyruvate]i and [glycerol 3-phosphate]/[dihydroxyacetone phosphate]i varied linearly (r=0.945), indicating equilibrium between the two cytoplasmic redox systems and with cytoplasmic NADH/NAD. Incubation in physiological salt solution (PSS) containing 10 mm pyruvate ([lact]/[pyr]=0.6) increased O2 consumption approximately 45% and produced anaplerosis of the tricarboxylic acid (TCA cycle), whereas incubation with 10 mm lactate-PSS ([lact]/[pyr]i=47) was without effect. A hyperpolarizing dose of external KCI (10 mM) produced a decrease in resting tone of muscles incubated in either glucose-PSS (−0.8+/−0.8 g) or pyruvate-PSS (−2.1+/−0.8 g), but increased contraction in lactate-PSS (1.5+/−0.7 g) (n=12-18, P<0.05). The rate and magnitude of contraction with 80 mm KCI (depolarizing) was decreased in lactate-PSS (P=0.001). Slopes of KCI concentration-response curves indicated pyruvate>glucose>lactate (P<0.0001); EC50 in lactate (29.1+/−1.0 mM) was less than that in either glucose (32.1+/−0.9 mm) or pyruvate (32.2+/−1.0 mM), P<0.03. The results are consistent with an effect of the cytoplasmic redox potential to influence the excitability of the smooth muscle and to affect mitochondrial energetics.
[0149] The cytoplasmic NADH/NAD redox potential affects energy metabolism and contractile reactivity of vascular smooth muscle. NADH/NAD redox state in the cytosol is predominately determined by glycolysis, which in smooth muscle is separated into two functionally independent cytoplasmic compartments, one of which fuels the activity of Na(+)-K(+)-ATPase. The effect was examined of varying the glycolytic compartments on cystosolic NADH/NAD redox state. Inhibition of Na(+)-K(+)-ATPase by 10 microM ouabain resulted in decreased glycolysis and lactate production. Despite this, intracellular concentrations of the glycolytic metabolite redox couples of lactate/pyruvate and glycerol-3-phosphate/dihydroxyacetone phosphate (thus NADH/NAD) and the cytoplasmic redox state were unchanged. The constant concentration of the metabolite redox couples and redox potential was attributed to:
1) decreased efflux of lactate and pyruvate due to decreased activity of monocarboxylate B-H(+) transporter secondary to decreased availability of H(+) for cotransport and 2) increased uptake of lactate (and perhaps pyruvate) from the extracellular space, probably mediated by the monocarboxylate-H(+) transporter, which was specifically linked to reduced activity of Na(+)-K(+)-ATPase.
[0152] It was concluded that redox potentials of the two glycolytic compartments of the cytosol maintain equilibrium and that the cytoplasmic NADH/NAD redox potential remains constant in the steady state despite varying glycolytic flux in the cytosolic compartment for Na(+)-K(+)-ATPase.
[0153] Methyl pyruvate has been described with reference to a particular embodiment. For one skilled in the art, other modifications and enhancements can be made without departing from the spirit and scope of the aforementioned claims.
[0154] Whilst endeavoring in the foregoing Specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature hereinbefore referred to whether or not particular emphasis has been placed thereon.
|
The present invention relates to the use of methyl pyruvic acid (a methyl ester of pyruvic acid) and/or methyl pyruvate (methyl pyruvate is the ionized form of methyl pyruvic acid) for the purpose of increasing muscle energy production. When used as a dietary supplement, energizer or pharmaceutical, this anion can be formulated as a salt. The methyl pyruvate compounds which can be used in the present method include: (1) a salt using a monovalent cation (such as sodium or potassium methyl pyruvate) or (2) a divalent cation (such as calcium or magnesium methyl pyruvate) and analogs of these compounds which can act as substrates or substrate analogs for methyl pyruvate Use of methyl pyruvate and/or methyl pyruvic acid can be effective when administered orally or infused on either a chronic and/or acute basis. In the following text, the terms “methyl pyruvate, methyl pyruvate compounds, methyl pyruvic acid” are used interchangeably.
| 0
|
CROSS-REFERENCES TO RELATED APPLICATIONS
Not Applicable
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK
Not Applicable
BACKGROUND OF THE INVENTION
The present invention is directed to integrated circuits and their processing for the manufacture of semiconductor devices. More particularly, the invention provides a method and system for monitoring implantation of silicon bearing species in semiconductor substrates for integrated circuit device structures. But it would be recognized that the invention has a much broader range of applicability. For example, the invention can be applied to a variety of devices such as dynamic random access memory devices (DRAM), static random access memory devices (SRAM), application specific integrated circuit devices (ASIC), microprocessors and microcontrollers, flash memory devices, and others.
Integrated circuits or “ICs” have evolved from a handful of interconnected devices fabricated on a single chip of silicon to millions of devices. Current ICs provide performance and complexity far beyond what was originally imagined. In order to achieve improvements in complexity and circuit density (i.e., the number of devices capable of being packed onto a given chip area), the size of the smallest device feature, also known as the device “geometry”, has become smaller with each generation of ICs. Semiconductor devices are now being fabricated with features less than a quarter of a micron across.
Increasing circuit density has not only improved the complexity and performance of ICs but has also provided lower cost parts to the consumer. An IC fabrication facility can cost hundreds of millions, or even billions, of dollars. Each fabrication facility will have a certain throughput of wafers, and each wafer will have a certain number of ICs on it. Therefore, by making the individual devices of an IC smaller, more devices may be fabricated on each wafer, thus increasing the output of the fabrication facility. Making devices smaller is very challenging, as each process used in IC fabrication has a limit. That is to say, a given process typically only works down to a certain feature size, and then either the process or the device layout needs to be changed.
As merely an example, implantation is a process that often needs to be changed with feature size. Implantation is often used to introduce impurities to change an electrical characteristic of the semiconductor substrate from a first type to second type. Here, P-type impurities and N-type impurities are often introduced into the substrate during one or more steps in the process of manufacturing integrated circuits. Such impurities are often characterized by dose and energy level, as well as other parameters, to control and maintain the manufacturing process. Implantation dose is often measured using a tool from Thermal Wave, such as the TP 500 , but can also be others. Silicon bearing impurities have also been used with the implantation process. Such silicon bearing impurities are often used in salicide Si implant and Si pre-amorphous. Unfortunately, many limitations exist in monitoring the dose of the silicon bearing impurities. That is, small changes in implantation doses often cannot be detected using conventional measurement tools. Accordingly, it becomes difficult to maintain monitor dosage levels of silicon bearing impurities in conventional processing such as implantation tools.
From the above, it is seen that an improved technique for processing semiconductor devices is desired.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, techniques including methods for the manufacture of semiconductor devices are provided. More particularly, the invention provides a method and system for monitoring implantation of silicon bearing species in semiconductor substrates for integrated circuit device structures. But it would be recognized that the invention has a much broader range of applicability. For example, the invention can be applied to a variety of devices such as dynamic random access memory devices (DRAM), static random access memory devices (SRAM), application specific integrated circuit devices (ASIC), microprocessors and microcontrollers, flash memory devices, and others.
In a specific embodiment, the invention provides a method for monitoring a dose of a silicon bearing implant. The method includes introducing a first implant species through a surface of a semiconductor substrate at a first dose and a first energy level and introducing a silicon bearing species through the surface of the semiconductor substrate at a second dose and a second energy level. The method anneals the semiconductor substrate and measures a sheet resistance value of the surface of the semiconductor substrate. The method also determines the second dose value based upon the surface resistance value. In an alternative specific embodiment, the invention provides a method for manufacturing integrated circuits on semiconductor substrates. The method includes inserting a test substrate into an implant tool. The method also includes introducing a base implant species through a surface of the test substrate at a base dose and a base energy level and introducing a silicon bearing species through the surface of the test substrate at a first dose and a first energy level. The method anneals the test substrate in an inert environment to activate the base implant species in the test substrate. The method measures a sheet resistance value of the surface of the test substrate. A step of determining the first dose value based upon at least the surface resistance value is included. The method uses the first dose to calibrate the implantation tool for a manufacture of semiconductor substrates and uses the implantation tool for the manufacture of semiconductor substrates.
Many benefits are achieved by way of the present invention over conventional techniques. For example, the present technique provides an easy to use process that relies upon conventional technology. In some embodiments, the method provides higher device yields in dies per wafer. Additionally, the method provides a process that is compatible with conventional process technology without substantial modifications to conventional equipment and processes. Preferably, the invention can be applied to a variety of applications such as memory, ASIC, microprocessor, and other devices. Depending upon the embodiment, one or more of these benefits may be achieved. These and other benefits will be described in more throughout the present specification and more particularly below.
Various additional objects, features and advantages of the present invention can be more fully appreciated with reference to the detailed description and accompanying drawings that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 through 5 illustrate a method according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, techniques including methods for the manufacture of semiconductor devices are provided. More particularly, the invention provides a method for forming small features such as contacts for integrated circuit device structures. But it would be recognized that the invention has a much broader range of applicability. For example, the invention can be applied to a variety of devices such as dynamic random access memory devices (DRAM), static random access memory devices (SRAM), application specific integrated circuit devices (ASIC), microprocessors and microcontrollers, flash-memory devices, and others.
A method according to an embodiment of the present invention for identifying a concentration of silicon bearing impurities for implantation is provided as follows:
1. Provide test wafer; 2. Implant test wafer using arsenic bearing impurities at first dose and first energy; 3. Implant silicon bearing impurities at second dose and second energy into the test wafer; 4. Anneal implanted test wafer; 5. Measure sheet resistance of implanted test wafer; 6. Repeat steps 1 through 5 for other test wafers using different dosages; 7. Form correlation between dosages and sheet resistance values; 8. Use correlation between dosages and sheet resistance values for at least one other test wafer or other test wafers; 9. Adjust implant process for the other test wafer; and 10. Perform other steps, as desired.
The present invention provides the above method for using test wafers to adjust an implantation process for correlation or calibration purposes. Such test wafers are not often production wafers. Sheet resistance values are used to correlate or calibrate the implantation process. The present method allows a user of the implantation process to adjust the process for implanting silicon bearing impurities. Further details of the present invention can be found throughout the present specification and more particularly below.
FIGS. 1 through 5 illustrate methods according to an embodiment of the present invention. These diagrams are merely an illustration and should not unduly limit the scope of the claims herein. One of ordinary skill in the art would recognize many other variations, modifications, and alternatives. As shown in FIG. 1 , the method begins by providing a silicon wafer 100 . The silicon wafer is a P-type wafer having an impurity resistivity of boron of about 2-5 ohms/cm, but can be others. As shown, the silicon atoms are arranged in a crystalline structure 101 , 103 of crystal orientation or others. The silicon wafer is a test wafer to be placed into an implantation tool to be monitored before release into production.
Referring to FIG. 2 , arsenic bearing impurities 105 are introduced through a surface of the wafer to a selected depth 201 . The arsenic bearing impurities are often introduced at a dose ranging from about 1.0 E 12 to about 1.0 E 13 . Depending upon the application, other impurities can also be used. Such impurities are often ones that do not substantially migrate upon subsequent thermal treatments. The arsenic bearing impurities increase a conductivity of the silicon material and serves as a base implant.
The method then introduces silicon bearing impurities 301 through the surface of the substrate as shown in FIG. 3 . The silicon bearing impurities are often derived from silane gas, such as SiF 4 . Depending upon the application, there can be other ways of deriving silicon bearing impurities. The implanted substrate is subjected to an anneal process, as illustrated by FIG. 4 . The anneal process causes the silicon ions to migrate into the lattice structure 403 as shown. Additionally, arsenic bearing impurities are also activated into the substrate. Preferably, a rapid thermal process is used. Such rapid thermal process subjects the implanted substrate to a temperature ranging from about 950° to about 1050° in an inert environment. Here, the environment can include nitrogen gas or other suitable non-reactive gas in certain embodiments. The method then measures a sheet resistance value of the substrate 500 , as shown by FIG. 5 . The sheet resistance value is often measured by RS-75 tool, but can be others. Preferably, the sheet resistance increase for higher doses of silicon bearing impurities. Here, the high resistance is caused by a lower density of arsenic bearing impurities, which dope the silicon substrate. Further details of this invention can be found throughout the present specification and more particularly according to the example below.
It is also understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims.
EXAMPLE
To prove the principle and operation of the present invention, we performed experiments. This example is merely an illustration and should not unduly limit the scope of the claims herein. One of ordinary skill in the art would recognize many other variations, modifications, and alternatives. In these experiments, we used two test wafers. Each of the test wafers was P-impurity type wafer. Such wafers had a concentration of about 2˜5 ohms/cm boron bearing impurities. These wafers were each implanted using the values and measurements provided in Table 1.
TABLE 1
Wafer Run Data
Wafer
Dose
TW
TW
Number
(%)
TW
(change %)
(sensitivity)
1
100
930.1
N/A
N/A
2
105
938.2
0.87
0.174
As shown, silicon was implanted at 35 KeV at 8E14 atoms/cm2. A thermal wave value was measured using a Thermal Wave TP 500 . The first wafer was at a 100% dose and the second wafer was at a 105% dose, which yielded TW values of respectively 930.1 and 938.2. The TW change % was less than 1%, i.e., 0.87%. The % change has been calculated as follows:
TW (change %)=[(938.2−930.1)/930.1]*100=0.87%
The TW sensitivity was 0.174. As shown below, the sensitivity has been calculated as follows:
TW sensitivity=(0.87%/5%)=0.174
where: 0.87% is the percentage change in TW; and 5% is the percentage change in doses from wafer 1 to wafer 2 .
Such sensitivity is not very accurate and can lead to difficulties in monitoring small changes in implant dosage values, which is a limitation of the conventional method.
We next ran wafers using aspects of the present method. Referring to Table 2, two wafers were prepared.
TABLE 2
Wafer Run Data
Wafer
Dose
Rs
Rs
Number
(%)
Rs
(change %)
(sensitivity)
1
100
2244
N/A
N/A
2
105
2351
4.77
0.954
The first wafer was at a 100% dose and the second wafer was at a 105% dose, which yielded sheet resistance values of respectively 2244 and 2351. The change is sheet resistance was 4.77%. A sheet resistance sensitivity value was calculated to be almost 1, which tracks the change in dosage. The method implanted silicon atoms at 30 KeV using a dose of 5.0E15 on pre-treated wafers, which were annealed after implantation. The pre-treated wafers were made by implanting arsenic bearing impurities at 60 KeV at a dose of 5.0E12 on P-type impurity test wafers. As shown, the Rs change was much more sensitive to small changes in implantation doses, which allows us to monitor implantation processes much more efficiently than conventional processes.
It is also understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims.
|
A method for monitoring a dose of a silicon bearing implant is described. The method includes introducing a first implant species through a surface of a semiconductor substrate at a first does of energy level and introducing a silicon bearing species through the surface of the semiconductor substrate at a second dose and a second energy level. The method anneals the semiconductor substrate and measures a sheet resistance value of the surface of the semiconductor substrate. The method also determines the second dose value based upon the surface resistance value.
| 7
|
BACKGROUND OF THE INVENTION
The present invention relates to a device for and method of elevating liquids.
Devices of the above mentioned general type are known in the art. The devices for elevating liquids through a discharge pipe with the utilization of solar or wind energy are disclosed in the U.S. Pats. Nos. 4,519,749 and 4,583,918, while the pipes for elevation of doses of liquids are disclosed in the U.S. Pats. Nos. 4,527,956 and 4,671,741. The devices disclosed in the U.S. Pats. Nos. 4,519,749 and 4,583,918 include a container- heat exchanger, an element which forms a dose of liquid, a discharge pipe, one or two liquid valves, and air taking diffuser. The operation of these devices is based on pushing from below upwardly of the formed doses of liquid through the discharge pipe by an expanding air during its heating in the heat exchanger. The elevation of the doses of liquid which in the discharge pipe assume the shape of liquid plugs or small columns, can be performed with the aid of the special pipes, for example the pipe disclosed in the U.S. Pat. No. 4,527,956. The inner space of this pipe is filled, with some interspaces, with a plurality of discs which are perforated. The diameter of perforations in the discs, the distance between the discs, and the value of forces of molecular interaction between the liquid and of the material of the discs produce such excessive capillary pressure that the plug of liquid in the vertical pipe is not dispersed and is not lowered under the action of gravity.
The pipe disclosed in the U.S. Pat. No. 4,671,741 also provides elevation of separate doses of liquid. Under the action of pressure difference, a dose of liquid is pumped from a lower container into an upper container through a pair of pipes, one of which insures the pumping of liquid while the other of which insures equalization of gas pressure in the lower and upper containers after pumping the dose of liquid from the lower to the upper level.
The devices disclosed in the U.S. Pats. Nos. 4,519,749 and 4,583,918 have some disadvantages, which include a complicated construction because of the use of liquid valves, consumption of a part of received energy for activating of the liquid valves, time spent for blowing through of the heat exchanger, limited coefficient of thermal expansion of gaseous working medium (air) and therefore use of the heat exchanger having a large volume which can exceed 10 times the volume of other parts in the event of 30° C. range (between 30° C. and 60° C.) of the thermodynamic cycle of operation of the device, limitation of the temperature coefficient of change in pressure of working medium by the value which is determined by the dependency of gas pressure from its temperature, absence of interrelationship between the time of running of phases of the thermodynamic cycle and intensity of wind action, and finally the necessity of having simultaneously two independent sources of energy , namely wind energy and thermal energy.
The disadvantages of the pipe disclosed in U.S. Pat. No. 4,527,956 include a relatively high resistance to flow of of liquid in the pipe because of the obstacles formed by the discs in the pipe, as well as maintenance expenses for cleaning dirt in the perforations of the discs and between the discs.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a device for and method of elevating liquids, which avoids the disadvantages of the prior art.
More particularly, it is an object of the present invention to provide a device for and a method of utilization of solar energy, wind energy, energy of waste or natural energy sources for elevating liquid, for example a heat source which changes the temperature of working medium of a heat engine relative to ambient temperature by 20°-30°, or a source of compressed or rarified air with a pressure exceeding atmospheric pressure by 50-100 mm hg column.
It is also an object of the invention to provide a device and a method which , with the use of thermal energy utilizes the principle of operation of a piston machine in which the working medium is a liquid to be elevated, the piston is a dose of the elevated liquid, and the cylinder is a discharge pipe with a stepped construction which does not limit the height of elevation of liquid, wherein in contrast to the known piston machine the inventive device does not have a step of returning the piston to its initial position.
It is also an object of the present invention to provide a device and method of elevating liquids, in which when the energy of compressed gas (vapor) is used as a motive power, no devices for transforming thermal energy into the energy of compressed gas (vapor)are needed; for example , in the event of use of a heat exchanger, no device for introducing into it a separate working medium is needed.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated , in a device which has a heat exchanging vessel for heating of a working medium which is a liquid to be elevated, and a discharge pipe connected with one another so that a liquid to be elevated is a working medium which is heated in a quantity which does not exceed the quantity required for performing one thermodynamic cycle, the liquid is introduced into the heat exchanger after the end or before the beginning of each thermodynamic cycle in a required quantity, and issuance of the elevated liquid into ambient atmosphere is performed under the action of a pressure difference with acts on the pipe and has a value which is equal to or greater than the pressure difference which elevated a dose of liquid.
When the device is designed and the method is performed in accordance with the present invention, the above objects of the invention are achieved.
Heat losses are minimized since only minimal quantity of working medium is heated, which is required for performing only one closed thermodynamic cycle. The heating of minimal quantity of working medium also insures a minimal delay between the variation of speed of heat supply from the heat carrier and the process of utilization of the received heat, which in condition of variations of heat carrier temperature reduces thermal energy losses. The thermodynamic cycle which takes place in accordance with the invention substantially corresponds to Renkin cycle, with higher efficiency coefficient as compared with the processes running in accordance with Carno cycle.
The novel features of the present invention are set forth in detail in the appended claims. The invention itself , however, both as to its construction and manner of operation will be best understood from the following description of preferred embodiments which is accompanied by the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-8 are views which schematically show a device for elevating liquids in accordance with the present invention, in different phases of its operation;
FIGS. 9-12 are views showing constructions of and processes running in lower parts of pairs of pipe portions which connect intermediate liquid accumulating containers of the device for elevating liquids in accordance with the present invention;
FIG. 13 is a view showing a position of upper ends of the pair of pipe portions in one of the liquid accumulating containers;
FIG. 14 is a view showing an inlet region of the discharge pipe of the device for elevating liquids in accordance with the present invention;
FIG. 15 is a view showing a hydraulic resistor or hydraulic diode at an outlet end of the discharge pipe of the inventive device; and
FIG. 16 is a view showing a diagram of thermodynamic condition of a system formed by the device in accordance with the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
A device for elevating liquids as shown in FIGS. 1-8 has a discharge pipe which includes a plurality of liquid accumulating intermediate containers 1.1-1.n which are located at equal distances one above the other. Each liquid accumulating container 1.k (k=1,2, . . . ,n-1) is connected with the respective lower container 1.k+1 by a pair of pipe portions 2.k and 3.k which are located at the same height and have equal lengths. The edges of the upper ends of the pipe portions of each pair are located in a horizontal plane.
The pipe portions 3.k are rectilinear and their axes are vertical. Each pipe portion 2.k has a lower end which is bent upwardly so that its upper open edge faces up as identified with reference 4.k in FIGS. 1-8,9 and 11),or
its lower end is inserted in a cup as identified with reference 20.k in FIGS. 10 and 12. The lower ends of the pipe portions 2.k and 3.k are located in the respective container 1.k at the height h 1 from its bottom. For the pipe portions 2.k the lower bend starts at the height h 1 . The upper ends of the pipe portions 2.k and 3.k are located in the container 1.k+1 at the height h 2 >h 1 from the bottom of the container 1.k+1 as more clearly shown in FIG. 13.
The edge of the bent end 4.k of the pipe portion 2.k (which is a bubbling pipe portion) or the edge of the cup 20.k into which the lower end of the pipe portion 2.k is inserted, is located at the height h 3 from the bottom of the container 1.k and corresponds to the ratio h 1 <h 3 <h 2 .
A part 5.k of the pipe portion 2.k whose lower section is located at a height h 3 +Δh has the area of the horizontal section which is greater than the area of the remaining part of this pipe portion. The height of this part 5.k (bubbling part of chamber) is shorter than the height of the bend 4.k of the pipe portion 2.k, and also shorter than the height of the ring formed between the pipe portion 2.k(h 3 -h 1 ) and the cup 20.k. The volume of the part 5.k is greater than the volume of the bend 4.k of the pipe portion or of the ring between the pipe portion 2.k and the cup 20.k.
The bubbling part 5.k can have an oval or round cross section. The height Δh must be such that the bubbling part 5.k does not prevent entering of the liquid into the bend 4.k of the pipe portion 2.k or into the cup 20.k.
An inlet of the discharge pipe is formed by a rectilinear pipe portion 6 which is connected with the lowest container 1.1. For example, it is inserted through the bottom of the container 1.1 and reaches such height h 4 (FIG. 14) that the container 1.1 can accumulate liquid with a volume which is determined by a dose of the liquid to be elevated. The outside part of the inlet pipe portion 6 has a height H 2 >H 1 and can be inserted into a reservoir 19 with liquid to be elevated (FIGS. 1-8 and 14) to the depth H 3 which satisfies the ratio H 2 >H 3 >H 1 , wherein H 1 is a height of the pair of the pipe portions.
An upper outlet of the discharge pipe is formed by a pipe portion 7 provided with a plurality of flat vertically spaced parallel discs 8 each having a plurality of perforations, for the case when the outlet opening of the discharge pipe is higher than the uppermost container 1.n (FIGS. 1-8). Or it is formed as a discharge pipe portion 22 (FIG. 15) located lower than the uppermost container 1.n. The pipe portion 22 is located in the uppermost container through its bottom and ends in a hydraulic resistor (throttle) or hydraulic diode 23 shown in FIG. 15.
The upper outlet of the discharge pipe is connected via a pipe portion 9 with an auxiliary vessel 10 with a discharge pipe portion 11. One leg of a U-shaped pipe 12 is inserted into the auxiliary vessel 10. A regulating needle is arranged on the bend of the pipe 12 as identified with reference 13. The second leg of the pipe 12 is connected with an upper part of a heat exchanger 14. The heat exchanger 14 accommodates a plurality of bottoms which act as individual evaporators 15 which have rough or ribbed surface. The lower part of the heat exchanger 14 is connected via a pipe 16 with an upper part of the lowest container 1.1. A conical member 17 is attached to the top of the container 1.1 at the lower side of the top, coaxially with the inlet pipe portion 6.
The lowest container 1.1 is subdivided by a partition 18 into two parts, so that the bubbling pipe portion 2.k is located in one part of a lower volume, while the pipe portion 3.k is located in the other part of a greater volume. The upper and lower parts of the partition 18 have openings through which two parts of the container 1.1 communicate with one another. Operation:
FIGS. 1-8 show various phases of thermodynamic working cycle of the operation of the device of the present invention. The initial position is shown in FIG. 1 and corresponds to the point A of the diagram of thermodynamic cycle shown in FIG. 16. The inlet pipe portion 6 of the device is introduced into a liquid 19 to be elevated to the depth H 3 as shown in FIG. 14. The lowest container 1.1 is filled with liquid to the height h 4 (FIG. 14). In other containers 1.i , wherein i=2,3, . . . , n-1 and in the pipe portions 3.i the level of liquid is located at the height h 5 from the bottom of the container 1.i (FIGS. 9 and 10), wherein h 1 <h 5 <h 3 . The level of liquid in the bend 4.i of the pipe portions 2.i or in the cups 20.i is at the height h 6 (FIGS. 9 and 10), wherein h 3 ≧h 6 >h 5 . The level of liquid in the uppermost container 1n is h 8 , wherein h 8 equal to the height of the lower end of the outlet pipe portion 7 above the bottom of the uppermost container (FIGS. 1-8). On the other hand, h 8 is zero when the outlet of the discharge pipe is formed by the pipe portion 22 with the hydraulic resistor (throttle) or hydraulic diode 23 located lower than the bottom of the uppermost container. The level of liquid in the inlet pipe 6 corresponds to the level of liquid in the reservoir with liquid 19 to be elevated. The level of liquid in the auxiliary vessel 10 and the introduced leg of the U-shaped pipe portion 12 corresponds to the level of the discharge pipe portion 11. The bottoms 15 retain in their depressions the liquid supplied from the previous cycle, and the pressure of air and vapor of the liquid in the heat exchanger 14, the containers and the pipe portions equal to the pressure of ambient atmosphere. Liquid which is not retained in the depressions of the rough or ribbed surface of the bottoms 15 flows via the pipe portion 16, the container 1.1 and the pipe portion 6 into the reservoir of the liquid 19 .
As a result of heating of the heat exchanger 14 and transfer of energy to the working medium in the latter (the heating can be performed by sources which will be explained below, the working medium is a liquid to be elevated in device), the pressure of air and vapor increase, the liquid in the pipe portions 2.1 and 3.1 is lifted upwardly, and correspondingly the liquid in the pipe portions 6 and 12 lowers (FIG. 2). At the pressure P 2 =P o +P 1 the pipe portions 2.1 and 3.1 are filled, while the level of liquid in the pipe portion 6 and in the leg of the pipe 12 introduced into the auxiliary vessel 10 lowers by the value H 1 (FIG. 3), wherein P 1 is the pressure of the column of elevated liquid with the height H 1 . The point B of the diagram of the thermodynamic cycle in FIG. 16 corresponds to the position of the system shown in FIG. 3. Since the volume of the heat exchanger considerably exceeds the volume of the pair of pipe portions 2.k and 3.k, and during the subsequent stages of elevations of liquid the height of the liquid in the pipe portions 2.k and 3.k remains equal H 1 while the level of liquid in the pipe portions 6 and 12 remains lower than that in the reservoirs in which they are inserted (by the value H 1 ), the transition from the position A to the position B can be considered as an isochoric process and the line AB is an isochore.
The further supply of energy into the heat exchanger leads to the flowing of the liquid from the container 1.1 to the container 1.2 (FIG. 4) . Since the value H 1 considerably exceeds the value h 4 , pumping of the liquid from the container 1.1 to the container 1.2 takes place in accordance with isochore-isobar. The position shown in FIG. 4 corresponds to the point C on the thermodynamic diagram of FIG. 16, while the line BC corresponds to the isochoreisobar. Subsequent supply of heat leads to an increase of pressure of gas (vapor) and its excess over the value P 1 . The gas (vapor) starts to bubble through the pipe portions 2.1 and 3.1 and flow into the container 1.2, and as a result of this the pressure of gas (vapor) in the container 1.2 increases and the pressure difference at the ends of the pipe portions 2.1 and 3.1 decreases with corresponding decrease of the liquid column in the latter. Simultaneously with the decreases of the height of the liquid column in the pipe portions 2.1 and 3.1, the height of the liquid column in the pipe portions 2.2 and 2.3 starts to increase (FIG. 5). At the gas (vapor) pressure in the heat exchanger equal to P 2 +ΔP the liquid from the second container 1.2 flows to the third container 1.3. ΔP is a pressure of the liquid column with the height H 4 =h 7 -h 1 , wherein h 7 is a height from the bottom of the container 1.k to the level of the liquid in the bubbling chamber 5.k, if the liquid level decreased from the position in which the liquid level in the bend 4.k of the pipe portion 2.k and in the pipe portion 2.k itself of the h 3 to the value h 1 in the bend 4.k or in the cup 20.k, under the action of gas pressure. The greater in the area of the horizontal cross section of the bubbling chamber 5.k, the lower is the value H 4 (FIGS. 11 and 12). Thus, the liquid flows from the second container 1.2 to the third container 1.3 (FIG. 6). This corresponds to the point C of the thermodynamic diagram of FIG. 16.
The process of flowing the liquid from a lower container 1.k to an upper container 1.k+1 takes place when the gas pressure in the system increases from the value P 2 +(k-1)ΔP to the value P 2 +k ΔP. Therefore the pressure in the system will be increasing in a stepped manner by the value ΔP during pumping of the liquid from one container 1.k to the other container 1.k+1. During this, the gas volume which is under the pressure P 2 +k ΔP increases by the value ΔV, wherein ΔV is a total volume of the container 1k and the pipe portions 2.k and 3.k. In the pipe portion 3.k the level of liquid is higher than the level of liquid in the container 1.k by the value H 4 , however the gas 21 will not bubble through the latter (FIGS. 11 and 12) since the end of the pipe portion 3.k is introduced into the liquid by the depth equal to h 5 - h 1 . After the pressure in the system reaches the value P 3 =P 2 +(n-1) ΔP, the liquid will start to be pushed out through an outlet end of the pipe portion 7 (FIG. 7) or 22 and 23 (FIG. 15). For pushing the liquid out of the outlet end of the pipe portion 7 or 22, a pressure difference must be created at the ends of this pipe portion, which is not less than the value P 1 . This is necessary, on the one hand, for pushing the liquid from the pipe portions 2.(n-1) and 3.(n-1) into the container 1.(n-1), and on the other hand, so that the issuance of the elevated dose of liquid will take place in a pulsating manner (as a pulse) as shown in FIG. 8. As a result of the pulsating ending of the issuance of the does of liquid, fast drop of pressure takes place in the system which includes the heat exchanger , the containers and the pipe portions connecting the same. As a result of this, an adiabatic expansion of gas takes place in the system, which is connected with the drop in the temperature and equilization of liquid level in the pipe portions 6 and 12 with the level of the liquid in which they are introduced.
In connection with the pulse nature of dehermetization of the system corresponding to the point N in FIG. 16, the liquid columns in the pipe portions 6 and 12 pass, as a result of inertia, higher than the level of liquid in which they are introduced. The liquid elevated in the pipe 6 is reflected from the surface of the conical reflecting member 17 and fills the container 1.1 to the height h 4 . The diameter of the pipe portion 6 is selected so that the liquid supplied through it into the container 1.1 insures the required volume of the liquid dose being elevated. In the pipe portion 12 the liquid reaches the region of the bend, passes through an opening which is regulated by the needle 13, and flows into the heat exchanger (FIG. 8). The quantity of the thusly flowing liquid is determined by means of the needle 13. A small cross section in the region of the needle prevents any possibility of siphoning out of the liquid from the vessel 10 by the pipe 12 to the heat exchanger 14.
In the heat exchanger 14 the liquid flows from one to the other bottom 15 and is retained (delayed) on the rough surfaces of the same , which form evaporators. If more liquid is supplied into the heat exchanger than needed for one thermodynamic cycle, then the excessive liquid flows down through the pipe portion 16 into the reservoir of the liquid 19 to be elevated. The elevated dose of liquid flows through the pipe portion 9 into the auxiliary vessel 10 and then from the latter flows into an ambient space through the pipe portin 11 (FIGS. 1-8). This insures the constant filling of the vessel 10.
Heating of the heat exchanger can be performed in many different ways, for example by the energy of solar rays even without special concentrating and focusing devices or with the use of the greenhouse effect; by the energy of waste heat in form of heated liquids, gases, natural thermal sources. The source of energy can also be sources of compressed gas, in which case the heat exchanger can be used as an intermediate container.
It is possible that the lower ends of the pipe portions 2.k and 3.k are located at the same height h 1 in the container 1.k, while the upper ends of the same pair of pipe portions in the container 1.k+1 are located at different heights, so that the upper end of the bubbling pipe portion 2.k is at the height h 2 +Δh 2 and the upper end of the other pipe portion 3.k of the same pair is at the height h 2 , wherein Δh 2 ≧0. This helps to more clearly distinguish the functions of the pipe portions of the pairs, which precludes the possibility of occurrence of oscillating process during the last stage of pumping the liquid which is elevated from the container 1.k to the container 1.k30 1. With this construction the bubbling (barbotating) pipe portion 2.k is used only for transfer of the gas from the container 1.k into the container 1.k+1, while the pipe portion 3.k is used for pumping the liquid from the container 1.k into the container 1.k+1.
It should be emphasized that the release of k pair of pipe portions 2.k and 3.k from liquid is performed as a result of equalization of pressure in k and k+1 intermediate container 1.k and 1.k+1 which are connected by the pipe portions 2.k and 3.k. Liquid which remained in the pipe portions 2.k and 3.k flows into the container 1.k. After issuance of the lifted dose of liquid from the top container 1.n outwardly through the pipe 22 the liquid which remains in the pipe portions 2.n-1 and 3.n-1 will not flow into the container 1.n-1 if in the last container 1.n there is no pressure which is equal to the pressure in the container 1.n-1. To produce the last mentioned pressure, the end of the pipe 22 is provided with a hydraulic resistance 23 which increases the pressure in the container 1.n to the value which is not less than the pressure of a liquid column with a height of the pipes 2.n-1 and 3.n-1 which connect the containers n-1 and n.
It should be emphasized that with the device of the present invention, it is therefore possible to elevate and issue any quantity of liquid at any height with a pressure difference which is not less (equal or greater) than the pressure difference required for elevation of one dose of liquid. More particularly, the required pressure difference is equal or only insignificantly greater than the pressure difference required for elevation of one dose of liquid.
The invention is not limited to the details shown.
What is desired to be protected is set forth in claims.
|
In a device for elevating liquids a heat exchanging vessel to be neated by an exterior source of heat is connected with a discharge pipe arranged to elevate doses of liquid, so that for performing a thermodynamic cycle the liquid to be elevated is used as a working medium, the liquid is introduced into the heat exchanger after an end or before a beginning of each thermodynamic cycle in a quantity which does not exceed a quantity required for one thermodynamic cycle and is heated in the heat exchanger, and issuance of the elevated liquid is performed under the action of pressure difference which acts on the discharge pipe and which has a value not exceeding a value of pressure difference which elevates a dose of liquid.
| 5
|
This application is a divisional of U.S. application Ser. No. 11/456,396, filed Jul. 10, 2006, issued as U.S. Pat. No. 7,851,733, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to air inlets, such as air inlets for missiles.
BACKGROUND OF THE INVENTION
A cannon-fired missile typically operates in a series of steps. A first launching charge provides the pressure required to eject the missile from a gun barrel in a desired direction. After this discharge step, the missile initiates a propulsion system, such as a propulsion force comes from an engine contained in the missile body. Engines used in missile design include rocket engines, gas turbine engines, and pulse jet engines, among others. Operation of a gas turbine or other air-breathing engine may require that the missile provide those systems typical of turbine operation, including for example, an air flow system from the exterior region of the missile to an engine inlet. Thus, designs for cannon-fired missiles often call for openings in the missile body that allow air to be pulled from the exterior of the missile and into the turbine engine section. In typical turbine engine operation, the air (or a portion of the air) that is pulled into the turbine engine section is then compressed, mixed with fuel, ignited, and discharged through a nozzle section to propel the missile.
A missile structure, and particularly those missile structures associated with cannon-fired missiles, may be subjected to high G forces during launching, including set back and balloting forces. Additionally, post-launching actions, such as air guide deployment and engine start-up, may further stress the missile structure. During flight missiles may also encounter the general turbulence and stresses associated with projectile flight. However, openings in the missile skin, such as an opening to allow air flow from the exterior of the missile to the interior of the missile, may present points of weakness in the missile structure.
Space and weight are often important factors in turbine engine design. This minimal engine weight then allows, among other advantages, for the range of the missile to be extended.
SUMMARY OF THE INVENTION
Methods and apparatus for delivering a missile may operate in conjunction with a missile comprising an outer skin. The missile may be configured in a closed position and an open position. In the open position, an aperture is opened in the outer skin, for example to supply air to an air-breathing engine. In the closed position, the aperture is closed.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the following illustrative figures. In the following figures, like reference numbers refer to similar elements and steps throughout the figures.
FIG. 1 is a perspective view of a missile that may include an air inlet with a multi-position air frame according to an embodiment of the present invention;
FIG. 2 is cut-away view of an aft portion of the missile;
FIG. 3 is a cross-sectional view of a portion of the missile in a closed position;
FIG. 4 is a cross-sectional view of a portion of the missile in an open position; and
FIG. 5 illustrates a trajectory of a missile.
Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that may be preformed concurrently or in different order are illustrated in the figures to help to improve understanding of embodiments of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
The present invention may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of hardware or software components configured to perform the specified functions and achieve the various results. For example, a system according to various aspects of the present invention may employ various frameworks, telescoping mechanisms, slidable elements, air inlet apertures, and the like, which may carry out a variety of functions. In addition, the present invention may be practiced in conjunction with any number of missile systems, projectiles, and/or inlet systems, and the system described is merely one exemplary application for the invention. Further, a system according to the present invention may employ any number of conventional techniques for opening and/or closing an aperture, forming the aperture, and the like.
Referring now to FIGS. 1 and 2 , a missile 10 according to various aspects of the present invention is configured to selectively open an aperture 19 after launch, for example to admit air for an air-breathing engine. The missile 10 may include any suitable components, such as an outer skin 11 , a nose section 12 , and an aft section 13 . The missile 10 may include control surfaces to control flight, such as aft fins 14 positioned on the aft section 13 of the missile 10 and forward canards 15 on the nose section 12 . The missile 10 may comprise a self-propelled missile, and may also include one or more engine outlets 16 or nozzles positioned on the aft section 13 . An engine 21 may comprise any suitable engine for propelling the missile 10 , for example a gas turbine engine, rocket engine, and pulse jet engine.
The outer skin 11 suitably defines an exterior 17 and interior region 18 of the missile 10 . The outer skin 11 may comprise any suitable material configured to define at least a portion of the exterior surface of the missile 10 . Positioned within the interior region 18 of the missile 10 , though not fully illustrated in FIG. 1 , are any suitable missile components, such as a fuel tank 22 , the engine 21 , a guidance system, and a payload, for example an explosive charge. Also positioned within the interior region 18 of missile 10 is a structural framework or airframe. The framework may comprise any suitable system for providing support to the outer skin 11 . The outer skin 11 may be affixed to the framework, for example via rivets, welds, or other suitable attachment mechanism.
The missile 10 may be configured to assume a closed position in which the aperture 19 is closed. For example, the missile 10 may be configured to be launched through a gun barrel. In one embodiment, when configured for gun barrel launch, the forward canards 15 and aft fins 14 can be positioned flush with the outer skin 11 . Additionally, the engine outlet 16 may be sealed or covered so as to allow a pressure charge to impinge on the aft section 13 of the missile 10 without damage to the engine or engine components. During launch, aperture 19 may be closed. The closure of aperture 19 for launch inhibits high pressure gases from entering into the interior region 18 of missile 10 so as to avoid damage from the gases. Further, the interface where the nose section 12 meets the aft section 13 may be configured to transfer and sustain structural loads associated with launch. For example, the interface may include a stepped lip on each of the nose section 12 and the aft section 13 where the nose section 12 and aft section 13 meet that are configured to mate.
The missile 10 may be configured to expose the aperture 19 formed in the outer skin 11 of the missile 10 after launch. The aperture 19 may be configured in any suitable manner, such as an annular aperture 19 formed in the outer skin 11 . In an open position, the aperture 19 facilitates air flow from the exterior region 17 of the missile, through the aperture 19 , and into the air-breathing engine 21 .
The present exemplary missile 10 may open the aperture 19 to expose an air passageway 23 defined by at least one passageway surface, such as a first air surface 24 and a second air surface 25 . The first air surface 24 and second air surface 25 may comprise any suitable surfaces or structures, for example to direct air into an air inlet 28 of the engine 21 . In one embodiment, the first air surface 24 and second air surface 25 each have, at least in part, a generally conical or frusto-conical, shape. The first air surface 24 may be defined by a first conical structure 26 , and the second air surface 25 may be defined by a second conical structure 27 . The first air surface 24 and second air surface 25 may be coordinated in shape and position so as to provide the air passageway 23 with desired airflow properties.
The missile 10 may include an aperture control system to selectively open the aperture 19 to expose the air passageway 23 . The aperture control system may comprise any suitable system for selectively opening the aperture 19 . For example, referring now to FIGS. 3 and 4 , the aperture control system may be connected to the outer skin 11 , either directly to the outer skin 11 or indirectly, for example via the framework. In the present embodiment, the aperture control system comprises a telescoping mechanism 35 that moves the aft section 13 and the associated aft skin section relative to the nose section 12 and the associated nose skin section between a closed position ( FIG. 3 ) and an open position ( FIG. 4 ). In one embodiment, the telescoping mechanism 35 includes multiple sets of slidable arms 31 . The slidable arms 31 can move longitudinally from the closed to the open position. The slidable arms 31 are connected to and/or form a portion of the missile framework, and the slidable arms 31 provide a point in the framework at which the framework can extend longitudinally. By moving from the closed to the open position, the slidable arms 31 act to open aperture 19 in the outer skin 11 of missile 10 . The longitudinal movement of the slidable arms 31 from the closed to the open position also acts to extend the overall length of missile 10 . The slidable arms 31 may also provide a structural joint in the airframe structure of missile 10 . The slidable arms 31 are positioned and structured so as to withstand torsional movement that arises from rotation of missile 10 . The slidable arms 31 further withstand the longitudinal pressures and stresses that the missile 10 experiences during flight as well as during launch.
The slidable arms 31 may be connected to the structural framework of the missile 10 . Forces upon the missile 10 can be transferred from a forward position to an aft position, and vice versa, through the slidable arms 31 . The connection between slidable arms 31 and the framework may comprise conventional connections, such as integral connections, rivets, bolts, and/or welds. In one embodiment, one member, either a male member 32 or female member 33 , is connected to a forward section of the structural framework, and the counterpart member is connected to the opposite section of the structural framework. A typical structural framework used in missile construction may have forms that are lattice-like or honeycombed in overall configuration. The components of the missile 10 , including the structural framework, outer skin 11 , aft fins 14 , forward canards 15 , and slidable arms 31 , may be constructed of conventional materials, such as aluminum or aluminum alloys for missiles and steel or titanium for projectiles.
In the present embodiment, each slidable arm 31 each includes a male member 32 and a female member 33 . Each pair of male member 32 and female member 33 may be formed so as to allow longitudinal movement between them. The longitudinal movement allowed is sufficient to permit the slidable arms 31 to move from the closed position, as shown in FIG. 3 , to the open position, illustrated in FIG. 4 . The male member 32 and female member 33 can take any suitable shape, such as square or rectangular in cross section. The reciprocal rectangular shape allows for a slidable fitting between members 32 , 33 for longitudinal movement while resisting the twisting that arises from torsional movement of the missile 10 .
When the male member 32 and female member 33 in the closed or the open position, a locking mechanism (not shown) may resist longitudinal movement of the slidable arms 31 . When a missile 10 is fired from a gun, the slidable arms 31 may locked in the closed position. The locking mechanism for the slidable arms 31 is capable of being unlocked so that, after firing, the slidable arms 31 can move to the open position. The locking mechanism may be selected from any suitable locking mechanism and/or actuator, such as explosive bolts, spring locks, and solenoid-activated bolts.
When in the open position, as seen in FIG. 4 , the slidable arms 31 may lock in the open position. The locking mechanism may be any suitable locking mechanism and/or actuator, such as spring locks and solenoid-activated bolts. The degree of locking may be sufficient to resist the torsional and longitudinal forces that the missile 10 encounters during launch and flight.
The movement of the slidable arms 31 causes a movement of the missile structure along the longitudinal axis of missile 10 . The longitudinal movement of the slidable arms 31 , and the corresponding movement of the missile structure, aligns the first air surface 24 and the second air surface 25 . The degree of travel that occurs in transitioning the missile 10 from the closed to the open position separates these surfaces by a desired amount so as to provide a desired shape to the air passageway 23 .
The aperture 19 may admit air substantially at all angular positions relative to the longitudinal axis of the missile 10 . In such an embodiment, any obstructions, including the slidable arms 31 , do not significantly restrict air flow through the aperture. The slidable arms 31 may exhibit a small enough cross-section so as not to unduly inhibit air flow through the aperture.
Referring now to FIG. 5 , the missile 10 may be loaded into a gun 51 , aircraft, submarine, or other system capable of launching the missile 10 . The missile 10 is initially in the closed position. In the closed position, missile 10 is capable of withstanding the pressures and stresses that would be encountered from firing so as to operate as intended after firing. Further, the aperture 19 may be sealed when in the closed position to inhibit damage to the missile 10 occurring from the penetration of gases through the closure seal into the interior of the missile 10 .
After the missile 10 is launched, the missile 10 may travels for a distance as a ballistic projectile without any self-propelled force. At some time after firing, the missile 10 may move to the open position and fire the engine 21 to initiate self-propelled flight. The trigger to convert to the open position and begin powered flight can be any suitable event, such as a time after launch or when the missile reaches a desired trajectory point 52 , for example the apogee of the cannon-fired trajectory. Upon opening, missile 10 exposes aperture 19 . The opening of aperture 19 allows engine 21 to receive air through air passageway 23 and into an air inlet 28 . During normal engine operation, the air mixes with fuel, burns, and exits through the nozzle. The continuous operation of the engine may draw a continuous flow of air through aperture 19 .
The missile 10 may continue powered flight along a desired path 53 until it reaches a desired point in its flight path. The missile 10 can be directed to its target 54 under power or through free fall.
While the invention has been described with reference to an exemplary embodiment, various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
|
Methods and apparatus for delivering a missile may operate in conjunction with a missile comprising an outer skin. The missile may be configured in a closed position and an open position. In the open position, an aperture is opened in the outer skin, for example to supply air to an air-breathing engine. In the closed position, the aperture is closed.
| 5
|
CROSS-REFERENCE TO RELATED U.S. APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
Not applicable.
REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to doors for pets, for example a door to allow the pets egress from or entry into a dwelling.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Pet doors of various kinds for cats and dogs are widely available. The doors for cats are usually called “cat flaps”.
Pet doors are adapted to be fitted in a lower portion of a wall or of an existing full-sized door. The pet door may consist simply of a flap, often being transparent so that the animal can see where it is going, and being hung from a horizontal axis to swing against the force of gravity when pushed by an animal. Alternative structures are mounted to swing about a vertical axis, but since they do not have gravity to bring the door/flap back to a closed position, they require springs to bias the door/flap to its neutral closed position. Also available are flexible transparent flaps, where the top of the flexible flap is held in fixed position and the animal bends the flap to make an entry or exit.
A simple latch may be provided for holding the door/flap at its neutral closed position so as to prevent movement of the door/flap in either direction or in just one direction. In the latter case, the latch may be arranged so as to allow entry but not egress or alternatively to allow egress but not entry.
The problem with such simple constructions is that, depending upon the position of the latch, any animal of the size to fit through the opening may gain entry or egress. In order to prevent passage of unwanted stray animals, pet doors have been designed with magnetically operable latches. The latch, powered by battery, is operable only when a magnetic tag (or in other operations an electrical loop) is detected. In simple mechanisms, any magnetic tag of adequate field strength will unlock the latch.
More sophisticated constructions have been designed in an attempt to allow selective operation of a door by a selected animal with the appropriate tag.
Pets commonly carry a subdermal identification coded tag. GB2376977 of Duerden, suggests transmitting a radio frequency signal at intervals to cause a signal to be transmitted by the standard passive coded subdermal identification tag carried by an animal, detection by a pet door of the retransmitted signal being adapted to open a pet door latch if the identification tag matches a code in memory. It is doubtful whether the Patentee had given any serious thought as to how the system could be put into effect. This prior proposal gives no detail as to how to effectively couple a transmitter or receiver at the pet door to a passive subdermal tag so as to get any useful received signal or how to discriminate between the millions of such tags in existence. In practice such subdermal tags can only be “read” by an interrogation coil placed on the skin immediately above the subdermal tag. If the tag has moved, in general it cannot be located. The poor coupling between an aerial associated with a pet door and the conventional subdermal tag, as well as the high energy requirements for a system based on utilizing such tags to control a pet door, makes a system of the kind proposed in GB2376977 unworkable.
GB1187383 of National Research Development Corporation is concerned with a somewhat different use, namely controlling access to different feeding spaces in a cow byre for different cows, in which each cow has a tag with a characteristic frequency effective to allow access only to its dedicated feeding space.
BRIEF SUMMARY OF THE INVENTION
In contrast to the prior art and in accordance with a first aspect of this disclosure, a pet door unit is adapted to allow entry to and egress from a dwelling of an animal. The pet door unit includes a pet door provided with a latch means, the pet door being mounted for movement to allow passage of the animal therepast when the latch means is disabled. The pet door unit is adapted to be fitted in one of: a lower portion of an existing door or window to allow entry or egress via the pet door when the existing door or window is closed, and a lower portion of a wall.
The pet door unit comprises:
an animal detector for detecting an animal apparently seeking passage past the pet door; a controller allowing selection of a permitted passage condition via the pet door, the permitted passage condition being selected from entry to the dwelling but not egress, egress from the dwelling but not entry, both entry to and egress from the dwelling, and neither entry to nor egress from the dwelling; and a selective latch disabler for selectively disabling said latch means to allow passage past the pet door; the disabler being coupled to the controller to disable the latch means in accordance with the selected permitted passage condition when the animal detecting means detects an animal seeking entry or seeking egress.
The term “latch means” as used herein is to be understood to mean any arrangement for latching a pet door. This may be a single latch or separate latches for respectively preventing entry and egress.
In a second and alternative aspect, a pet door unit is adapted to control entry to and egress from a dwelling of an animal, the pet door unit including a pet door provided with latch means, the pet door being mounted for movement to allow passage of the animal therepast when the latch means is disabled. The pet door unit is adapted to be fitted in one of: a lower portion of an existing door or window to allow controlled entry or egress via the pet door when the existing door or window is closed, and a lower portion of a wall.
The pet door unit further comprises:
a clock; a controller coupled to the clock and including a selector for selecting a permitted entry period in which the animal is allowed entry to the dwelling, and a permitted exit period in which the animal is permitted egress from the dwelling; an animal detector coupled to the controller for detecting whether an animal appears to be seeking entry or egress via the pet door; and a selective latch disabler for selectively disabling said latch means to allow passage past the pet door, the disabler being coupled to the controller to disable the latch means to allow entry when the animal detector detects an animal seeking entry during said permitted entry period, and also to disable the latch means to allow egress when the detecting means detects an animal seeking egress during said permitted exit period.
In a third alternative aspect, a pet door unit is adapted to control entry to and egress from a dwelling of a plurality of animals, each animal being provided with a detectable tag identifying the particular animal, the pet door unit including a pet door provided with latch means, the pet door being mounted for movement to allow passage of the animal therepast when the latch means is disabled. The pet door unit is adapted to be fitted in one of: a lower portion of an existing door or window to allow controlled entry or egress via the pet door when the existing door or window is closed, and a lower portion of a wall.
The pet door unit comprises:
a clock; a controller coupled to the clock and including a selector for selecting, for each said tag, a permitted entry period in which the animal associated with that tag is allowed entry to the dwelling, and a permitted exit period in which the animal associated with that tag is permitted egress from the dwelling; an animal detector coupled to the controller for detecting whether an animal appears to be seeking entry or egress via the pet door; a tag detector adapted to detect the presence of a said tag in a region adjacent the pet door; and a selective latch disabler for selectively disable said latch means to allow passage therepast, the disabler being coupled to the controller to disable the latch means to allow entry at a time when both the tag detector detects a tag and the animal detector detects an animal seeking entry during said permitted entry period for that tag, and also to disable the latch means to allow egress when both the tag detector detects a tag and the animal detector detects an animal seeking egress during said permitted exit period for that tag.
The tag may be detected by infra-red detection, magnetic detection, or inductive loop detection.
The animal detector may comprise two reed switches, each having a closed state and an open state, operable by a magnet carried by the pet door. The pet door has a central median position, the pet door, when latched, being movable through a first minor distance from the central median position in a direction into the dwelling by an animal pushing the pet door from outside in that direction. The arrangement of reed switches and magnet is such that the open or closed state of a first of the two reed switches is changed by movement of the pet door through the said first minor distance. The pet door, when latched, is movable through a second minor distance from the central median position in a direction out of the dwelling by an animal pushing the pet door from inside in that direction. The arrangement of reed switches and magnet is such that the open or closed state of the second of the two reed switches is changed by movement of the door through the second minor distance.
In a fourth alternative aspect, a pet door unit is adapted to control entry to and egress from a dwelling of a plurality of permitted animals, each animal being provided with a detectable tag, the tags being the same or different. The pet door unit includes a pet door provided with latch means, the pet door being mounted for movement to allow passage of the animal therepast when the latch means is disabled. The pet door unit is adapted to be fitted in one of: a lower portion of an existing door or window to allow controlled entry or egress via the pet door when the existing door or window is closed, and a lower portion of a wall.
The pet door unit comprises:
a tag detector operatively adapted to detect the presence in a region adjacent the pet door of a tag identifying a permitted animal; and a latch disabler for disabling said latch means for the pet door to allow permitted passage therepast to an animal bearing a tag so detected, said disabler being operable within a selected period of permitted passage associated with the said tag, the period of disablement of the latch means before it is enabled again allowing passage of the animal bearing the detected tag past the pet door.
The pet door unit has a power saving mode in which the tag detector and the latch disabler remain inactive and the door remains latched, and an active mode in which the tag detector is operable and in which the latch disabler is also operable if a tag associated with a permitted animal is detected by the tag detector during a period of permitted passage associated with the tag.
The pet door unit further comprises an animal detector separate from the tag detector for detecting whether an animal appears to be seeking passage via the pet door, the animal detector being adapted to initiate the active mode when an animal's presence is detected and the pet door unit is in power saving mode.
In this case, the animal detector may comprise one or more reed switches, each reed switch having a closed state and an open state and being operable by a magnet carried by the pet door. The pet door has a central median position. The pet door, when latched, is movable through a first minor distance from the central median position in a direction into the dwelling by an animal pushing the pet door from outside in that direction. The arrangement of the one or more reed switches and the magnet is such that the open or closed state of the or a first of the reed switch(es) is changed by movement of the pet door through the first minor distance. The pet door, when latched, is movable through a second minor distance from the central median position in a direction out of the dwelling by an animal pushing the pet door from inside in that direction. The arrangement of the one or more reed switches and the magnet is such that the open or closed state of the or a second of the reed switch(es) is changed by movement of the pet door through the first minor distance.
In all the above units, where two reed switches are employed, preferably the two reed switches are mounted alongside each other in proximity to an edge of the pet door. Each reed switch is generally tubular in configuration to define a longitudinal direction, and one reed switch is displaced relative to the other in its longitudinal direction into the dwelling, while the other reed switch is displaced relative to the one in its longitudinal direction out of the dwelling. The magnet comprises a magnet mounted in said edge so that in the central median position of the pet door the magnet is effective to close both reed switches, movement of the pet door through the first minor distance by being pushed from outside being effective to move the magnet to a position in which it opens said one reed switch. Movement of the pet door through the second minor distance by being pushed from inside is effective to move the magnet to a position in which it opens the other reed switch.
Opening detection means may be provided to detect whether the pet door has been opened subsequent to the latch means being disabled. Means are preferably provided to delay at least one of initiation of the active mode and operation of the animal detector when, on a predetermined number n of occasions within a set period, an animal has been detected by the animal detector as apparently seeking passage via the pet door without subsequent opening of the pet door being detected by the opening detection means. As explained in the detailed description hereinbelow, this feature helps to preserve battery power with a diffident cat or in windy conditions where false indications that an animal is present at the pet door might occur.
According to a fifth alternative aspect, a pet door unit is adapted to control entry to and egress from a dwelling for at least one animal, the pet door unit including a pet door provided with latch means. The pet door is mounted for movement to allow passage of the animal therepast when the latch means is disabled, the pet door having a central median position in which it is latched. The pet door unit is adapted to be fitted in one of: a lower portion of an existing door or window to allow controlled passage via the pet door when the existing door or window is closed, and a lower portion of a wall.
The pet door unit further comprises:
a latch disabler for disabling said latch means to allow passage of an animal; and a latch enabler for enabling the latch means to re-latch the pet door after an animal has passed therepast and the pet door has returned to its central median position, and including a door position detector for detecting whether the door is located in its central median position.
The disabler may be controllable to allow passage for the animal in a selected entry or egress direction.
The door position detector preferably comprises one or more reed switches, each reed switch having a closed state and an open state and being operable by magnet means carried by the pet door. The arrangement of the one or more reed switches and the magnet is such that the open or closed state of a first of the reed switch(es) is changed by movement of the pet door from the central median position into the dwelling. The arrangement of the one or more reed switches and the magnet is such that the open or closed state of a second of the reed switch(es) is also changed by movement of the pet door from the central median position out of the dwelling.
Preferably there are two reed switches, namely said first reed switch and said second reed switch. The two reed switches are mounted alongside each other in proximity to an edge of the pet door, each reed switch being generally tubular in configuration to define a longitudinal direction, and one reed switch being displaced relative to the other in its longitudinal direction into the dwelling, while the other reed switch is displaced relative to the one in its longitudinal direction out of the dwelling. The magnet comprises a magnet mounted in said edge so that in the central median position of the pet door the magnet is effective to close both reed switches. Movement of the pet door from the central median position into the dwelling is effective to move the magnet to a position in which it opens said one reed switch, and movement of the pet door from the central median position out of the dwelling being effective to move the magnet to a position in which it opens said other reed switch.
In a sixth alternative aspect, a pet door unit is adapted to control entry to and egress from a dwelling for an animal, the pet door unit including a pet door that is mounted for movement to allow passage of the animal therepast. The pet door has a central median position. The pet door unit is adapted to be fitted in one of: a lower portion of an existing door or window to allow entry or egress via the pet door when the existing door or window is closed, and a lower portion of a wall.
The pet door unit further comprises:
an electrically operable determinator for determining in which direction the animal last passed the pet door and adapted to provide an indication whether the animal is likely to be within the dwelling or outside, the determinator including an opening detector adapted to detect that the door has been opened by at least a predetermined amount indicative of an animal having passed the pet door.
Preferably, the electrically operable determinator comprises: a direction of movement detector for determining, when the pet door leaves its central median position, in which direction it moves; and an extent of movement detector comprising a reed switch having a closed state and an open state and being operable by magnet means carried by the pet door; the arrangement of the reed switch and the magnet being such that the open or closed state of the reed switch is changed by a movement of the pet door from the central median position in either direction sufficiently for the animal to have passed therepast.
A clock may also be provided, together with means for recording the time of last passage of an animal past the pet door.
In a seventh alternative aspect, a pet door unit is adapted to control entry to and egress from a dwelling for a plurality of animals, each provided with a detectable tag with a different identity. The pet door unit includes a pet door that is mounted for movement to allow passage of the animal therepast, the pet door having a central median position. The pet door unit is adapted to be fitted in one of: a lower portion of an existing door or window to allow controlled entry or egress via the pet door when the existing door or window is closed, and a lower portion of a wall.
The pet door unit further comprises:
a tag detector adapted to detect the identity of a tag in a region adjacent the pet door; an animal passage determinator for determining that an animal has passed the pet door and in which direction; and a store coupled to said determinator for storing, for a particular passage via the pet door, the direction detected by the determinator and the identity of the tag as detected by said tag detector.
That an animal has passed the door and in which direction can be detected in various ways, including infra-red detectors mounted on either side of the door. However, the determinator preferably comprises: a direction of movement detector for determining, when the pet door leaves its central median position, in which direction it moves; and an extent of movement detector comprising a reed switch having a closed state and an open state and being operable by a magnet carried by the pet door. The arrangement of the reed switch and the magnet is such that the open or closed state of the reed switch is changed by a movement of the pet door from the central median position in either direction sufficiently for the animal to have passed therepast.
The pet door may further comprise a clock, and a recorder coupled to the clock for recording for each of said tags both the time and direction of last passage of the animal associated with that tag past the pet door.
In a preferred arrangement, the pet door is mounted for rotation on a pivot about a horizontal or vertical axis, and said extent of movement detector comprises a magnet located on the door at one axial end of the pivot to rotate therewith. The reed switch is mounted in a fixed position in confronting relation to the magnet.
The direction of movement detector may comprise one or more reed switches, each reed switch having a closed state and an open state and being operable by a co-operating magnet carried by the pet door. The arrangement of the one or more reed switches and the magnet is such that the open or closed state of one of the reed switch(es) is changed by one of movement of the pet door from the central median position into the dwelling and movement of the pet door from the central median position out of the dwelling.
In a preferred arrangement, the direction of movement detector comprises two reed switches mounted alongside each other in proximity to an edge of the pet door, each of said two reed switches being generally tubular in configuration to define a longitudinal direction. One reed switch is displaced relative to the other in its longitudinal direction into the dwelling, while the other reed switch is displaced relative to the one in its longitudinal direction out of the dwelling. The co-operating magnet comprises a magnet mounted in said edge so that in the central median position of the pet door the magnet is effective to close both reed switches, movement of the pet door from the central median position into the dwelling being effective to move the magnet to a position in which it opens said one reed switch. Movement of the pet door from the central median position out of the dwelling is effective to move the magnet to a position in which it opens said other reed switch.
In all the above arrangements in different aspects, where a pair of reed switches are employed, the two reed switches are preferably connected in series across a source of electric potential by a first reed of a first one of said two reed switches being connected to a first reed of the second one of said two reed switches in a circuit providing first and second inputs on first and second lines. The first line is connected to a second reed of said first one of the two reed switches, and the second line is connected both to the first reed of said first one of the two reed switches and to the first reed of the second one of said two reed switches. Detection of the potential of the second reed of the second one of the two reed switches on the first line indicates that both reed switches are closed and the pet door is in its median central position. Detection of the potential of the second reed of the first one of the two reed switches on the first line and the potential of one of the second reeds of the two reed switches on the second line indicates that the pet door has moved, the direction being determined by which of the two potentials is present on the second line. Detection of the potential of the second reed of the first one of the two reed switches on the first line and a potential other than those of the two second reeds on the second line indicates that the pet door is open.
In an eighth alternative aspect, a method of recording movement of an animal past a pet door to determine whether the animal is within or outside a dwelling provided with the pet door and the time interval since the animal last passed through the pet door comprises the steps of:
providing the animal with an interrogatable passive tag; transmitting an interrogation signal receivable by a said tag in a vicinity close to the pet door, said transmitting step being triggered by an animal seeking passage through the pet door; determining from which side of the door the animal was seeking passage; determining from said interrogation signal whether the tag has been identified, and, if so, disabling the latch for a period sufficient for the animal to make passage past the pet door; and determining whether the pet door has in fact opened sufficiently for passage of the animal during the period in which the latch was disabled, and if so, recording the time and direction of such passage.
Although the embodiment of pet door unit described in detail hereinbelow is adapted for electrical detection of tags worn by permitted animals, other arrangements are possible. For the purpose of some aspects of this disclosure, it is not necessary that animals wear any tag at all. In some cases, detection of the presence of an animal or a permitted animal may be by infrared, by magnetic coupling or, as in the arrangement described in detail below by decoding the modulation of an interrogation signal caused by coded tags worn by the animals. Each tag may then comprise a coil to couple with a coil of the pet door unit, a capacitor and a binary coded microchip. In electrical systems, coupling to a passive tag worn by an animal is inductive, and improved coupling will achieve better results.
In an eighth alternative aspect, a pet door unit is adapted to control entry to and egress from a dwelling of a plurality of permitted animals, each animal being provided with a tag detectable by inductive coupling with a coil mounted on the pet door unit, the tags being the same or different. The pet door unit includes a pet door provided with latch means, the pet door being mounted for movement to allow passage of the animal therepast when the latch means is disabled. The pet door unit is adapted to be fitted in one of: a lower portion of an existing door or window to allow controlled entry or egress via the pet door when the existing door or window is closed, and a lower portion of a wall.
The pet door unit further comprises:
a tag detector, including said coil, operatively adapted to detect the presence in a region adjacent the pet door of a said tag identifying a permitted animal; and a latch disabler for disabling the latch means to allow permitted passage past the pet door to an animal bearing a tag so detected, said disabler being operable within a selected period of permitted passage associated with the said tag, the period of disablement of the latch means before it is enabled again allowing passage of the animal bearing the detected tag past the pet door.
The coil circumextends about the perimeter of the pet door and is diverted from the periphery of the pet door below the pet door to a position adjacent the lower edge of the pet unit to enhance coupling with a tag attached to the collar of an animal and hanging beneath its neck.
The latch mechanism of the detailed embodiment of pet door unit described in detail with reference to the accompanying drawings is believed novel in itself. Accordingly, in a ninth alternative aspect, a pet door unit is adapted to control entry to and egress from a dwelling of one or more permitted animals. The pet door unit includes a latchable pet door that is mounted for movement to allow passage of an animal therepast when its latch is disabled. The pet door unit is adapted to be fitted in one of: a lower portion of an existing door or window to allow controlled entry or egress via the pet door when the existing door or window is closed, and a lower portion of a wall. The latch comprises a latch member constrained to move in a generally vertical direction into and out of engagement with the pet door to latch it and unlatch it, and being provided with drive means therefor, comprising an electric motor and a rotatable drive rod coupled to the said motor. The drive rod is coupled to turn a wheel provided with an eccentrically mounted pin, the latch member including an elongate through slot, the longitudinal direction of the slot being generally horizontal. The pin is constrained to slide in said slot, whereby rotation of the drive rod by the motor is effective to rotate the wheel so that its pin slides in the horizontal slot, causing the latch member to be raised or lowered depending on the direction of rotation of the motor.
The drive rod may be coupled to turn a second wheel mounting an opaque sector plate adapted to occlude a light sensor to provide an indication of the position of the latch. One or both of the wheels may be coupled to the drive rod via a worm drive.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
An embodiment is hereinafter more particularly described, by way of example only, with reference to the accompanying drawings.
FIG. 1 is an overall perspective view of a pet door unit with a housing cover omitted to show internal parts, and with other parts omitted for clarity.
FIG. 2 is an enlarged cross-sectional view illustrating the latch mechanism.
FIG. 3 is a cross-sectional view similar to FIG. 2 with the latch plate omitted to show otherwise hidden parts.
FIG. 4 is a much enlarged partial perspective view of a corner of part of the unit adjacent one corner of the pet door, with parts omitted for clarity.
FIG. 5 is a schematic view of a reed switch.
FIGS. 6 and 7 are schematic circuit diagrams of reed switch circuits.
FIG. 8 is a much enlarged partial perspective view of the unit adjacent one end of the pet door pivot.
FIGS. 9 and 10 are logic diagrams of use in explaining operation of preferred embodiments.
DETAILED DESCRIPTION OF THE INVENTION
Pet doors are commonly sold as a unit to be fitted through a lower portion of an existing door intended for human use, so as to allow entry and egress for pets via the pet door when the existing door is closed.
FIG. 1 is an overall perspective view of an embodiment of a pet door unit comprising a pet door proper (here a vertically mounted flap adapted to turn on a horizontal axis), associated housing, latch and control mechanisms. Flap 1 is mounted in a housing 3 , suitably moulded of plastics, which includes a generally tubular section or tunnel 4 , here of generally square cross-section, which is adapted to pass through a correspondingly shaped, but slightly larger, opening formed through the lower portion of an existing door or window to allow mounting of the pet door therein. Main portion 5 of the housing fits flush against and is fixed to the inner side of the existing door, which may be of any conventional construction, including glass, pvc, metal and wood, or window. There may be a further face plate or housing portion (not shown) that fits over the tunnel 4 and flush against the outer side of the existing door or window to provide a neat appearance. It will be understood that main portion 5 is fitted with a cover (omitted to allow the mechanism to be seen) which has a central opening therein corresponding to the shape of and slightly larger than the flap 1 .
It will be appreciated that, provided the tunnel is long enough or a bespoke tunnel is formed, the pet door unit may, alternatively, be fitted through a wall rather than an existing door. However, for the purpose of this description, it is assumed that the unit is fitted to an existing door.
The pet door unit is provided with a latch mechanism 6 , generally indicated and operated by battery power from a stack of batteries 7 under control of a processor 8 , which may have one or more indicators or buttons 9 and/or an LCD screen 10 adapted to present instructions and/or information in alpha-numeric form.
As explained in detail below, the latch mechanism in this case comprises a single latch plate that operates to latch the door against opening in either direction. In alternative arrangements, there may be an individual latch on either side of the door, one serving to prevent entry, and the other serving to prevent egress.
In the illustrated arrangement, latch mechanism 6 comprises an electric motor 11 , the spindle 12 of which is adapted, via a coupling 13 , to rotate a drive rod 14 (best shown in the enlarged views of FIGS. 2 and 3 ) mounted for rotation in bearings 15 , 16 , 17 and 18 . Coupling 13 comprises a first disc 19 mounted on spindle 12 and having a plurality (here two) of projections 20 extending parallel to the spindle axis from forward face 21 of disc 19 . Projections 20 are received in through openings 22 in a second disc 23 mounted on one end of drive rod 14 . Projections 20 are enabled to slide in the axial direction in through openings 22 so as to accommodate any tolerance or movement between drive rod 14 and spindle 12 in the axial direction of the drive rod. The bearings 15 , 16 , 17 and 18 may be formed of first bearing parts integrally moulded with housing main portion 5 and second bearing parts that cooperate with the first and are integrally moulded in the cover (not shown) for main housing portion 5 . Drive rod 14 may be a simply pushed into the first bearing parts of bearings 15 , 16 , 17 and 18 before the cover is fitted to complete the bearings. It is prevented from moving by any substantial distance in its axial direction by lands 24 . Drive rod 14 mounts a worm 25 which is adapted to drive a cog wheel 26 . Cog wheel 26 mounts an eccentric pin 27 which is adapted to slide within a slot 28 formed in a latch plate 29 . Latch plate 29 is constrained to slide vertically within slots 30 , 31 formed in face 32 of main housing portion 5 .
As can be seen from FIG. 3 , from which latch plate 29 has been omitted, slots 30 , 31 each have a cranked configuration so as to define lower portions 30 a , 31 a which are separated from each other by a greater distance than upper portions 30 b and 31 b of the slots. Latch plate 29 has projections 33 , 34 that extend sideways from a lower portion of the latch plate 29 and mount pins (not illustrated) adapted to be guided in lower portions 30 a and 31 a of the slots. The face of latch plate 29 opposite that illustrated in FIG. 2 carries two further guide pins (not illustrated) which are guided in the upper portions 30 b and 31 b of the slots. Thus, as drive rod 14 turns and cog wheel 26 rotates driven by worm 25 , eccentric pin 27 is allowed to slide in slot 28 , and this causes the latch plate 29 to slide vertically upwards or vertically downwards, depending upon the direction of rotation of the drive rod, guided in slots 30 and 31 . Latch plate 29 has an upper end bifurcated to form two separate latch members 35 , 36 adapted to engage in blind openings formed in the lower edge of flap 1 .
Drive rod 14 mounts a second worm 37 adapted to drive a cog wheel 38 mounting a semi-circular sector plate 39 formed of a non-transparent material and adapted to occlude a light sensor 40 to provide an indication to processor 8 as to whether latch plate 29 is in its raised position to provide latching engagement with flap 1 , or not.
The above described latch mechanism is believed novel in itself and may be employed regardless of whether or not the system cooperates with passive tags worn by animals, as explained below. While this latch mechanism is preferred in the embodiment of pet door unit described in detail below, it will be understood that other forms of latch mechanism may be substituted in alternative embodiments.
A variety of different systems are currently employed to detect an animal at or close to a pet door for controlling its operation. Many of the novel features described herein and embodied in the specific embodiment of pet door unit illustrated in the accompanying drawings will find utility in pet door units operating on different systems of detection, including infra-red detectors.
However, in the preferred arrangement, one or more pets associated with the household in which the illustrated pet door has been mounted in a door to allow entry and egress for those pets are each provided with a passive tag comprising a binary coded microchip and an oscillatory circuit including a pick-up coil. Different tags are given different binary codes. The pet door is provided with a coil of wire (omitted for clarity) adapted to transmit an interrogation signal at a high frequency to interrogate the binary code in exactly the same fashion as subdermal pet identification tags are “read” through the skin by placing an interrogator coil on the skin surface.
It is explained below how it is possible to enhance coupling between the coils to get useful results. The resultant modulation of the waves of the interrogation signal by different amounts for “0”s and for “1”s in the binary code, as energy is transferred to the pick-up coil of the tag via an inductive link between the coils, enables the processor 8 to determine the binary code of the tag from the interrogation signal. Thus, processor 8 may be pre-programmed to enable it to determine whether a tag so detected identifies a pet permitted to enter or permitted to exit. That recognition of permission may then cause the latch mechanism to be driven to release the latch and allow entry or egress as the case may be. The processor 8 and latch mechanism 6 thus act as a latch disabling means when a permitted tag is detected. Because a plurality of pets may be given tags with different binary codes, this enables the system to control entry and exit of a plurality of different pets within the same household whose windows of opportunity for entry and exit may be set to be different from each other.
This feature is believed novel in itself in pet doors and may be employed independently of other features disclosed herein.
The present embodiment of pet door unit enables the entry and exit of a number of different pets to be controlled with entry and exit windows that may be different from each other.
For the system to work efficiently, a reliable inductive link must be created between the pet door coil and the coil in the tag worn by the pet. Since the tag will suitably be mounted on the animal's collar, it is likely to be positioned close to the pet door when the animal is seeking entry or egress, and beneath the animal's neck. A channel 41 is defined in the face of main portion 5 of the housing to accommodate the pet door coil (not shown). The coil must obviously run around the perimeter of flap 1 . It will be noted, however, that, beneath the flap, channel 41 is diverted from the periphery of the flap 1 to as low as possible a position 42 adjacent the rim of main portion 5 of housing 3 . By this means, the maximum possibility for inductive coupling between the pet door coil and the coil of an animal's tag coil hanging beneath its collar is created, and thus the maximum opportunity for a permitted tag to be detected. The coil preferably operates at a frequency of 125 kHz.
Latches operable by tags worn by pets have been provided in pet doors previously with coils running around the periphery of the flap proper. However, as far as presently aware, it has never previously been suggested to divert the pet door coil from the periphery of the flap to the lowest possible position within the pet door unit beneath the flap so as to achieve maximum coupling with a tag hanging from the collar of a pet approaching the pet door. The better the inductive coupling, the more reliable is the system, whatever form of tag is employed, and the need for repeated interrogations before entry or egress is allowed can be reduced. The present novel coil geometry is applicable to both the present binary coded microchip tags and to other more conventional tags adapted to operate a pet door latch via an inductive link.
If an interrogation signal were provided continuously, the batteries 7 would very soon run down. Indeed, a structure of the kind described would simply not be workable without a main electricity supply in place of batteries. However, a system has been devised which allows for conservation of battery power.
As explained below, the presently described embodiment causes the processor 8 to generate an interrogation signal when a pet is present at the pet door. This is possible because animals, especially cats, habitually push the door/flap before trying to make passage past it. It has been found that the fact that the door/flap has been pushed, and from which side, can readily be determined by the provision of appropriate reed switches. Preferably, as shown, two reed switches 43 , 44 are mounted adjacent a corner of the door/flap, and best shown in the greatly enlarged view of FIG. 4 .
A reed switch RS (see FIG. 5 ) commonly comprises two magnetic contacts C 1 and C 2 within a glass or ceramic tube T filled with a protective gas. When a magnet comes close to the reed switch RS by displacement or by rotation, so that one out of the two contacts C 1 and C 2 becomes magnetized to be more “North” than the other, the two contacts will be attracted to each other to complete an electric circuit through the switch. Otherwise, the contacts C 1 and C 2 separate and the circuit opens.
As can be seen, in particular from FIG. 4 , reed switches 43 and 44 are mounted beneath flap 1 adjacent one corner thereof. Although the two reed switches are mounted essentially in the same horizontal plane they are mounted both skew rather than normal to the vertical plane of the flap and staggered relative to each other so that one reed switch 43 extends beyond the flap 1 when it hangs in its vertical position in the direction of the exterior (the tunnel 4 side of the flap) while the other reed switch 44 is displaced slightly in the other direction, namely into the dwelling side of the cat flap in use.
The edge of flap 1 adjacent the two reed switches 43 and 44 carries a magnet adapted to operate those reed switches.
The magnet is preferably aligned with the edge of the flap. When the flap is in its medial central position, both reed switches are off-set from the medial position in opposite directions. This means that for each reed switch, one of its reeds will be more exposed to the magnet than the other, causing attraction between its reeds, so that the switch is closed. Thus, when the flap is exactly in its median central position, both switches will be closed. However, when, for example, a cat approaches the cat flap from the exterior (tunnel 4 ) side, its habit will generally be to push with its paw against the flap. This causes the flap to move slightly (the latch is designed to allow small movements even when latched). This causes a displacement of the magnet in the edge of the flap so that it now magnetises both reeds of switch 44 equally. When the door is unlatched, and moves further, the magnet first closes reed switch 44 as the effect on the two reeds of that switch again become unbalanced. As it moves even further, it will cease to have any substantial differential effect on the reeds of either switch, so that both will be open.
Thus noting the pattern of opening or closing of the two reed switches of the described arrangement, enables the system to tell not only from which side a cat is seeking to open the flap when it is latched, but also whether the flap then opens after being unlatched.
Thus, the arrangement of the two reed switches 43 and 44 enables the system to know whether the flap is at rest, whether a cat is attempting to make entry, whether a cat is attempting to make egress and whether the flap is open. The logical information is set out in Table 1 below.
TABLE 1
Reed 44
Reed 43
Information
Flap is at rest
Closed
Closed
Flap at rest, do nothing saving power
Flap moved from
Closed
Open short
Flap moved from inside. If cats are
inside
time
allowed out then start looking for tag.
When tag found, if that tag is allowed
out, then open lock
Flap moved from
Open short
Closed
Flap moved from outside. If cats are
outside
time
allowed in then start looking for tag.
When tag found, if that tag is allowed in,
then open lock
Flap open
Open
Open
Do not lock the flap until flap closed
Flap closed
Closed
Closed
When both reeds open, lock can be shut,
as flap is in the centre. The flap is
locked as soon as is possible to stop
other cats getting in or out
The two reed switches 43 and 44 may be linked to processor 8 by a simple circuit such as that shown in FIG. 6 in which an input on line L 1 indicates that reed R 1 is closed and an input on line L 2 indicates that reed R 2 is closed. However, it is preferred to employ the alternative circuit of FIG. 7 which employs only a single power connection and uses essentially half the power that would be required for the circuit of FIG. 6 , and involves a modified logic.
The alternative logic involved with this circuit is explained in Table 2.
TABLE 2
Input L1
Input L2
Flap is at rest
Ground voltage
Input not used
Flap moved
Positive voltage -
If ground voltage, reed R2 open.
start looking at
If positive voltage, reed R1 open
Input L2
Flap open
Positive voltage
Not positive or ground
Flap closed
Ground voltage
Input not used
Other arrangements are also possible. Thus if the magnet is vertically aligned to present a pole to the switches, then when the flap is centrally located in its median vertical plane, the magnet will cause both reed switches 43 and 44 to be closed. Pushing the flap from the exterior (tunnel 4 ) side may cause the flap to move to displace the magnet in the edge of the flap sufficient to disengage reed switch 43 while leaving reed switch 44 engaged. Conversely, when a cat approaches the flap from the dwelling side with, pushing the flap slightly may cause just sufficient movement of the magnet in the edge of the flap to disengage reed switch 44 while leaving reed switch 43 engaged.
In this construction, further movement on unlatching the door will result in movement of the magnet out of reach of both reed switches so that both will be open.
The use of the two reed switches, as discussed above allows the system to know whether an animal is seeking to enter or to leave the dwelling, which information can be used to control a latch, and also to know whether the door subsequently opens after being unlatched. Thus, regardless of whether any tags are fitted to the household pets, the two reed switch arrangement may be used to trigger unlatching while keeping the latch otherwise closed. A four-way control of the latch becomes possible, namely: open for entry and closed for egress; closed for entry and open for egress; closed both ways; and open both ways.
However, it is preferred to use the knowledge of attempted use, and from which side, in a more sophisticated control system employing tags. This is explained with reference to the logic diagrams of FIGS. 9 and 10 .
The system employs a programmable processor, preferably a PIC16F627a or PIC16F870 processor, the processor being operated from a microchip of the read/write analogue front end type for 125 kHz RFID base station. A suitable such microchip is sold by E M Micro Electronic under the designation EM4095.
The tags for permitted animals must first be calibrated to the processor. This is achieved by the following routine:
1. Press the “tag” button (for example button 49 ) for a set period (say 5 seconds). 2. The display flashes. 3. The tag is moved close to the flap. 4. That an interrogation signal from the processor and the pet door coil has detected the presence of the tag is indicated by the flashing slowing down. 5. The binary code of the particular tag is then stored in the processor by pressing a “set” button (such as button 50 ). 6. Steps 1 to 5 are repeated for up to 7 further tags.
For each said tag, periods for allowed entry and for allowed egress must be programmed into the processor following a menu set in the processor. The individual tags, after having their digital code stored in the processor, must then be fitted to the collars of individual pets such as cats. Thereafter, the system operates essentially as shown in the logic flow diagram of FIG. 9 .
The default setting 51 , or “waiting stage”, runs the system in power-saving mode, consuming very little power from the batteries. In that power saving mode, the system checks periodically at step 52 whether either of the reed switches 43 or 44 has operated (is open). If the switch has operated, the system checks at 53 whether the cat in question is trying to enter or leave the dwelling, this being determined, as explained above, by switches 43 and 44 . If a cat is trying to come in, then, at step 54 , a check is made whether, at the particular time, any of the permitted cats is allowed to come in. If the answer is “no”, then the system is returned to its waiting power-saving mode 51 . If the answer is “yes”, then the system looks for a tag at step 55 .
As explained above, looking for a tag involves sending out an interrogation signal via the pet door coil. At step 56 , the system determines whether any permitted tag is detected. If no permitted tag is detected, then, at step 57 , a check is made whether a predetermined number of seconds have elapsed since the system started looking for a tag. If it has not, then the system recycles to look for a tag again. If the predetermined period has elapsed and no permitted tag has been detected, then the system assumes that it is a stray cat that is trying to get in, and the system remains locked and returns to its power-saving mode 51 . If a tag is detected at step 56 , then a check is made at step 58 whether the tag so detected identifies a cat that is allowed, at the particular time, to go in. If that detected tag does not have permitted entry at the time in question, the system returns to its waiting power-saving mode 51 . However, if the detected tag is associated with a cat that does have permission to enter at the time in question, the flap is unlocked at step 59 by energizing motor 11 to rotate drive rod 14 , and so cause latch plate 29 to move downwardly to release the flap.
A check is made at step 60 whether the flap has been opened, this check being made by reed switches 43 , 44 , as explained above, subsequent to being unlocked. If the flap has not been opened, then a check is made at step 61 to see whether a predetermined number Y of seconds has elapsed since the flap was unlocked. If it has not, then, after a short interval, the system checks again at step 60 whether the flap has been opened. If at check 61 the period of Y seconds has elapsed since the flap was unlocked, then the system moves to step 62 . Also at step 60 , if the flap has been opened, then the system passes to step 62 . In this step 62 , the system checks whether the flap is in its centre position. This is also determined by the two reed switches 43 and 44 . If both are closed then the flap is in its medial central vertical position. If the flap is not in its centre position then, after a brief delay, the system checks again at step 62 whether the flap is in its centre position. If the flap has been opened and the flap has returned to its medial central position as detected at step 62 , it is safe to lock the flap again in step 64 and return the system to its waiting mode 51 .
Essentially identical steps will be followed (Right-hand side of FIG. 9 ) if it was determined at step 53 that the cat was trying to get out. Processor 8 has a clock and may thus record successful passage of the cat past the pet door (“Yes” at step 60 ) and the direction (Step 53 ) of passage.
With the system described above and adopting the logic shown in FIG. 9 , problems may still occur in conditions where the wind is sufficient to repeatedly move the flap, or where a cat is particularly diffident in using the flap and repeatedly pushes the flap before actually making passage therepast. In either of these conditions, this will result in high power usage. In the standard system of FIG. 9 , if (say) the flap is pushed every 10 seconds by a cat or moved every 10 seconds by the wind, the system would go flat using standard size A batteries in around 4 hours. Of course it is unlikely that a cat that is locked out would try repeatedly to get in for 4 hours in any one go but even trying for 3 minutes every day, this would have the effect of reducing a standard 9 months battery life down to just 2 to 3 months. The protocol illustrated in the logic diagram of FIG. 10 overcomes these problems and in practical examples, has been shown to save up to 94% of the battery life. Use of the protocol of FIG. 10 , even with a cat that repeatedly pushes the flap for 3 minutes every day, will have the effect of reducing battery life from the standard 9 month period by only as little as 10 days.
As will be appreciated, the protocol of FIG. 10 applies at step 55 of the FIG. 9 logic. The system is requested at 65 to look for a tag as a result of the answer “yes” being achieved at step 54 . At step 66 , the system checks whether it has looked for a tag 5 times in the last 20 minutes and not unlocked the flap. If the answer is “yes”, then the system moves straight to step 67 and looks for a tag for up to ¼ second on and ¼ second off up to two times. It then waits for 10 seconds at step 68 if it did not find a tag, and then moves on to step 51 . However, if the answer at step 66 is “no”, so that the system has not looked for a tag 5 times within the past 20 minutes without unlocking the flap, then the system moves to step 69 , and asks whether it has looked for a tag in the past 30 seconds without unlocking the flap. If the answer to this is “yes”, then the system moves to step 70 , and looks for a tag for up to ¼ second on and ¾ second off for up to 6 times before moving to step 51 . However, if the answer at step 69 is “no”—the system has not looked for a tag in the last 30 seconds without unlocking the flap—then the system moves to step 71 , and looks for a tag for up to 1¾ seconds, and then to step 72 if it did not find a tag, and looks for a tag for up to ¼ second on and 1¾ second off for up to 5 times before moving to step 51 of the FIG. 9 logic.
With this protocol, the system will still be able to find a tag quickly except in the circumstance where a succession of false positives have recently occurred, and even in this situation the maximum time that a cat that does have permission to come in may have to wait will be 10 seconds. Thus, a balance is struck between efficiency and power saving.
Even after the latch has opened, a cat may simply push the flap but not make an entry past it. This may show up as an indication at stage 60 that the flap has opened. By use of a further reed switch in our preferred embodiment, as now explained with reference to FIGS. 1 and 8 , it can be told for certain whether a cat has passed through the pet door. In this arrangement, the door consists of a flap 1 mounted for rotation about a horizontally extending axis defined by respective pivots 45 and 46 . A third reed switch 47 is fixedly mounted in confronting relation with a magnet 48 that is mounted on one pivot 46 so as to be rotatable with the flap. Magnet 48 is aligned so that the North-South alignment of its poles is at right angles to the longitudinal direction of the reed switch 47 when the flap 1 hangs vertically in which condition the switch is closed providing an input to processor 8 . Rotation of the flap through an angle of (say) 45° or more, corresponding to passage of an animal through the pet door past the flap, will rotate the magnet by the same substantial angle and cause the switch to open. However, movement of the flap only by a small angle is not sufficient to open the reed switch. Thus, the system is enabled to know whether a pet has actually passed through the flap rather than merely pushed the flap from one side, and then retreated. Since the system already knows through reed switches 43 and 44 from which side the animal was coming, this means that the system knows at any time whether a particular pet has passed through the pet door and so is either inside the dwelling or outside.
As the processor includes a clock, it may be programmed to store the time of last passage through the pet door for any tag, and in which direction. A pet owner can thus tell whether a particular pet has been out for a prolonged period and may therefore be missing.
In a household that has only a single pet, this third switch, coupled with the double reed switch to tell from which direction the animal was approaching the door, provides information whether the animal is in or out, regardless of whether it is wearing a tag or not; and this may be coupled with a time stamp for each (or the last) opening of the door to provide passage.
Other arrangements for telling whether the door has opened sufficiently for an animal to pass therepast are also feasible. These may include infra-red detectors on either side of the door, or a system in which switches are operated by the door at predetermined angles of opening indicative of an animal passing the door.
The illustrated embodiment has a flap hung from a horizontal axis. The invention in all its aspects is equally applicable to doors mounted to swing on a vertical axis. In such an arrangement, the reed switches 43 , 44 may be located adjacent the edge of the door away from its axis, or along either the upper or lower edges of the door at a position away from that axis. The same principle may be applied to arrangements in which the flap is fixed at its top edge, but is formed of flexible material that is displaceable by an animal passing the pet door and then returns to its original medial central position. In this case, the reed switches 43 , 44 may be located, as in the illustrated embodiment adjacent the lower edge of the flap.
The detailed description of operation of the illustrated embodiment refers to cats. The systems disclosed herein will work equally well for a pet door designed to be used by dogs. Unlike cats, dogs tend to be more positive in approaching a pet door. Whereas a cat will usually push at the door with its paw with a noticeable delay before it actually passes through the door, dogs tend to push straight into the door with an expectation that it will open for them. Nevertheless, the moment a dog pushes into the door, this will cause one of the reed switches to open. This brings the system out of its power-saving mode. The logic steps may be adjusted to be performed at a rapid rate so that a permitted dog hardly notices a delay before the latch is released and the door yields to their push.
|
A pet door unit allowing entry to and egress from a dwelling of an animal includes a pet door provided with a latch. The pet door is mounted for movement to allow passage of an animal when the latch is disabled. The pet door unit includes an animal detector for detecting an animal seeking passage past the pet door. A controller allows selection of a permitted passage condition. A disabler selectively disables the latch. Other arrangements described include systems for controlling entry and exit for different animals in different time frames, systems that detect an animal by a tag carried by the animal, systems that detect a door, systems that detect whether an animal has actually passed through the door and in which direction, and systems that record time and direction of passage, a preferred coil geometry for tag detection, and a preferred latch.
| 4
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to toilets (sometimes referred to as "water closets"). More particularly, the present invention relates to toilets having a tank for providing flush water. Still more particularly, the present invention relates to a toilet having a tank for providing flush water, the toilet having two flush modalities: a conventional flush operation for solid waste and a separate urinal flush operation for only liquid waste.
2. Description of the Prior Art
Toilets serve admirably as an efficient and sanitary means to dispose of waste material. Toilets operate upon a flush cycle, wherein waste disposal is performed with the accompaniment of a large quantity of water, usually on the order of three, four or more gallons.
As population densities have increased, the demands upon available water supplies have become quite substantial. Indeed, periodically, certain locales are subject to water rationing, wherein flushing of the toilet is requested to be performed only infrequently. Such a request not only subjects the toilet user to odor, but potentially also to disease due to the stagnancy of pre-used bowl water. Accordingly, a solution to the water demands of toilet flushing with each toilet use would be extremely desirable for both personal and ecological reasons.
One "popular" notion to reduce the amount of flush water needed is to place an object in the tank, such as a water filled plastic milk container, the volume of which diminishing the water volume in the tank. While this sounds not only feasible but practical, one must consider why, in the first place, the toilet manufacturer designed the tank to hold a specified amount of flush water. First, there must be enough flush water to move solid waste in the bowl out of the toilet and into the sanitary drain. Second, there must be still more flush water to flush out the dirty bowl water while at the same time rinsing the bowl clean. Thirdly, there must be enough flush water left over to provide an adequate depth of water at the trap located at the bottom portion of the bowl so that the sanitary drain is fluidically cut-off from the bowl to thereby prevent methane and other sewer gases from backing-up into the bowl, and, thereupon, into the restroom. Thus, reducing the amount of flush water by simply reducing the water stored in the tank may result in insufficient water to properly flush the bowl. More potentially disastrous, is that over time an accumulation of solid waste may become lodged in the sanitary drain, plugging the drain and resulting in back-ups because repeatedly too little flush water was available to move the solid waste out the local sanitary drain and into the main sanitary drain.
Some toilets operate on a flush process wherein less flush water is required, such as described in U.S. Pat. No. 4,987,616 to Ament, dated Jan. 29, 1991. Other toilets combine a lesser amount of flush water in combination with a compressed gas principle. Problematically, these toilets may be subject to drain clogging if insufficient flush water is available to move the flushed solid waste out into the main sanitary drain.
The flushing of liquid waste requires less flush water than does the flushing of solid waste, since the flushing of liquid waste does not entail the potential for drain clogging. Accordingly, what is needed is a toilet which uses only an amount of water which is needed to effect full and complete flushing based upon the particular type of waste being flushed.
SUMMARY OF THE INVENTION
The present invention is a toilet which operates on the basis of two flush modalities: one for flushing solid waste, and a second for flushing only liquid waste.
The two flush modality toilet according to the present invention is composed of a bowl, a tank connected with the bowl wherein the tank is connected to a water supply, a conventional flush modality for flushing solid waste from the bowl, and a urinal flush modality for flushing liquid only waste from the bowl, wherein the urinal flush modality includes: a bowl valve at the lowest point of the bowl, a bowl valve control for selecting between open and closed states of the bowl valve, a conduit for directing liquid waste from the bowl into the sanitary drain, and an auxiliary flush control for supplying a limited quantity of flush water from the tank into the bowl to provide restoration of the trap water in the bowl after a urinal flush modality has been initiated.
A foot pedal selectively operates the bowl valve, wherein when in an open state all the liquid in the bowl is drained. Upon release of the foot pedal, the bowl valve is returned to a closed state. Flush water from the tank is then delivered to the bowl to restore the trap water.
Operation may be mechanically effected or electronically effected. With regard to mechanical operation, the flush water from the tank may be introduced by action of the foot pedal or by separate action of a control at the tank.
Accordingly, it is an object of the present invention to provide a two flush modality toilet.
It is another object of the present invention to provide a two flush modality toilet, wherein the amount of flush water used is dependent upon whether solid or liquid only waste is being flushed.
It is a further object of the present invention to provide a two flush modality toilet, wherein the amount of flush water used is dependent upon whether solid or liquid only waste is being flushed, wherein operation conserves water.
It is yet a further object of the present invention to provide a two flush modality toilet, wherein the amount of flush water used is dependent upon whether solid or liquid only waste is being flushed, the invention being adaptable to existing toilets or provided with newly manufactured toilets.
It is yet another object of the present invention to provide a two flush modality toilet, wherein the amount of flush water used is dependent upon whether solid or liquid only waste is being flushed, wherein the mechanism is simple and reliable.
It is an additional object of the present invention to provide a two flush modality toilet, wherein the amount of flush water used is dependent upon whether solid or liquid only waste is being flushed, wherein operation is easy for a user.
These, and additional objects, advantages, features and benefits of the present invention will become apparent from the following specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partly sectional side view of a two flush modality toilet according to the present invention, showing a mechanically actuated form thereof.
FIG. 2 is a perspective view of a base for the two flush modality toilet of FIG. 1.
FIG. 3 is a partly cut-away perspective view of the tank of the two flush modality toilet of FIG. 1.
FIG. 4 is a partly sectional detail view of the bowl and base of the two flush modality toilet of FIG. 1, shown with the flush valve in a closed state.
FIG. 5 is a partly sectional detail view of the bowl and base of the two flush modality toilet of FIG. 1, shown with the flush valve in an open state.
FIG. 6 is a partly sectional side view of the tank of the two flush modality toilet of FIG. 1, shown delivering auxiliary flush water to the bowl.
FIG. 7A is a partly sectional side view of a two flush modality toilet according to the present invention, showing an electrically actuated form thereof.
FIG. 7B is an exemplary circuit schematic for carrying out the electrical function of the two flush modality toilet of FIG. 7A.
FIG. 8 is a partly sectional side view of a two flush modality toilet according to the present invention, showing a mechanically actuated form thereof absent a separate base, and depicting an alternative auxiliary flush control.
FIG. 9 is a partly sectional side view of a tank of the two flush modality toilet of FIG. 8, showing the auxiliary flush control thereof in operation providing auxiliary flush water to the bowl.
FIG. 10A is a partly sectional side view of the tank of a two flush modality toilet according to the present invention, showing one form of a separately operable tank mounted auxiliary flush control.
FIG. 10B is a partly sectional side view of the tank of a two flush modality toilet according to the present invention, showing another form of a separately operable tank mounted auxiliary flush control.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a two flush modality toilet 10 according to the present invention is depicted. The two flush modality toilet 10 includes a bowl 12, a tank 14, a bowl valve 16 composed of a bowl valve stopper 55 and a bowl valve seat 58 therefor, a bowl valve control 18, and an auxiliary flush control 20 at the tank. The tank 14 is connected with an external source of pressurized potable water via a supply pipe P in a conventional manner well known in the art. The structure and function for providing actuation of the conventional flush modality is determined conventionally by operation of a conventional flush control 22 including: a conventional flush lever 22a, a conventional flush feed 22b for supplying flush water from the tank to the bowl, a conventional float stopper 22c for selectively sealing the conventional flush feed, and a conventional tank water height sensing water inflow valve 23 which is connected to the supply pipe P for refilling the tank with flush water. Preferably, the conventional tank water height sensing water inflow valve is of the kind without a ball-float and rod-arm, as these components could make the tank interior too crowded to allow for the auxiliary flush control, as for example the FLUIDMASTER (a registered trademark) Model 400A fill valve manufactured by Fluidmaster, Inc. of Anaheim, Calif. 92803.
The bowl 12 includes a trap 24 defined by a depending projection 26, an upleg portion 28 of the bowl outlet 30, and a downleg portion 32 of the bowl outlet. The upleg and downleg portions 28, 32 are of a generally inverted U-shape, wherein the upleg portion defines in part the bottom portion of the bowl 12. The height of the upleg portion 28 is higher than the location of the terminous 26a of the depending projection 26. Accordingly, when water 34 fills the trap 24 at the bottom portion of the bowl 12 to a height approximated by the height of the upleg portion 28, the water immerses the terminous 26a of the depending projection 26, thereby sealing-off the bowl from the drain 36. The trap 24 has a lowest point whereat the bowl valve 16 is located; accordingly, when the bowl valve is opened all the liquid in the trap will drain therethrough.
In operation, when a user has completed using the two flush modality toilet 10 the user selects the flush modality. If solid (and/or liquid) waste is present in the bowl 12, the user selects the conventional flush modality by pressing the conventional flush lever 22a. If only liquid waste is present in the bowl 12, the user may select (as an alternative to selecting the conventional flush modality) a urinal flush modality by actuating the bowl valve 16 to thereby drain the liquid waste from the bowl and actuating the auxiliary flush control 20 to thereby restore the water at the trap 24 of the bowl 12.
The structure and function for carrying out the two flush modality toilet 10 will be detailed hereinbelow with reference being additionally directed to FIGS. 2 through 6.
A base 38 is provided, preferably constructed of plastic, which forms a platform upon which the toilet proper 40 is situated. As shown in FIG. 2, and as can be appreciated by comparative reference to FIG. 1, the base 38 is provided with a drain hole 42, a drain cavity 44 connected with the drain hole 42 via a passageway 46, and a recess 48. (There is no communication between the recess and the drain cavity.) The drain hole 42 is aligned with the downleg portion 32 of the bowl outlet 30 and is in sealing relation thereto via a wax seal 35'. The drain cavity 44 is aligned with a bowl valve throat 45 (which carries the aforementioned bowl valve seat 58) via a wax seal 35". Consequently, when the conventional flush modality is selected, flushing discharge from the bowl 12 exits the bowl outlet 30, goes into the drain hole 42 and into the drain 36. Consequently further, when the urinal flush modality is selected, the liquid in the trap 24 drains out the bowl valve 16, goes through the the bowl valve throat 45, enters into the drain cavity 44, passes through the passageway 46, enters into the drain hole 42, and then enters into the drain 36.
The bowl valve throat 45 is preferably constructed of a stiff elastomeric material, and the bowl valve seat 58 is either integrally formed with the bowl valve throat, or is separately sealingly engaged with respect thereto. The bowl is provided with an aperture 15 at the lowest point of the trap 24, whereat the bowl valve throat is sealingly engaged, such as by a press fit therebetween which may be further sealed by a sealant therebetween. In this regard, the bowl valve stopper 55 is composed of any suitable material which will seal it with the bowl valve seat 58.
The base 38 is mounted to the bottom of the toilet proper 40 by any suitable methodology, such as by the toilet mounting bolts 25, wherein holes 25a are provided therefor in the base. The base 38 is sealed with respect to the drain 36 via a wax seal 35.
The bowl valve control 18 is composed of a foot pedal 50, a linkage 52, and an actuation lever 54 which is pivotally connected with the bowl valve stopper 55. The linkage 52 includes a linkage rod 52a, a biasing spring 52b, and a linkage arm 52c connected with the linkage rod. The linkage 52 is generally situated within the recess 48, wherein the linkage rod 52a is pivotally mounted thereto, and wherein a first portion 52a' exits the base 38 and connects with the foot pedal 50. A link 56 connects the linkage 52 at the linkage arm 52c to the actuation lever 54. The actuation lever 54 is pivotally connected with the bowl valve throat 45 and is generally in sealing relation therewith. The biasing spring 52b biases the linkage rod 52a so that the bowl valve stopper 55 is in sealing engagement with the bowl valve seat 58, wherein the bowl valve 16 is in the closed state.
In operation, as shown in FIGS. 4 and 5, when the foot pedal 50 is depressed to a down position against biasing of the biasing spring 52b, the actuation lever 54 pivots and pulls the bowl valve stopper 55 of the bowl valve 16 downwardly away from the bowl valve seat 58, wherein the bowl valve is in the open state. Now, whatever liquid is in the bowl will drain in accordance with the above recounted urinal flush modality through the bowl valve throat and, as recounted, into the drain 36. Upon release of the foot pedal 50, the biasing of the biasing spring 52b will cause the foot pedal to rise to an up position and the bowl stopper 55 of the bowl valve 16 to reseat in sealing relation with respect to the bowl valve seat 58, wherein the bowl valve is returned to the closed state.
In order that the proper amount of flush water is introduced into the bowl 12 depending upon the selected flush modality, the tank 14 is equipped with two flush controls: a conventional flush control 22 and an auxiliary flush control 20.
When the conventional flush modality is selected, the conventional flush lever 22a is turned, separating the float stopper 22c from the conventional flush feed 22b in a conventional manner, wherein new water will enter into the tank from the external water line via the conventional tank water height sensing water inflow valve. Flush water 60 from the tank 14 will enter into the bowl 12 conventionally and exit the bowl outlet 30 as described hereinabove. After the flush water 60 is exhausted, the conventional float stopper 22c sealingly seats on the conventional flush feed 22b, and the conventional tank water height sensing water inflow valve within the tank will turn off the incoming water when the tank water reaches its predetermined height.
When the urinal flush modality is selected, it is desired to only supply enough water to the bowl 12 to refill the trap 24; about one gallon is sufficient for this purpose. In order that not all the tank water is flushed into the bowl 12 when the foot pedal 50 is depressed, an auxiliary tank 62 is provided within the tank 14, wherein the auxiliary tank holds auxiliary flush water 64 having a volume only enough to fill the trap 24, again, more-or-less about a gallon of water.
The linkage rod 52a includes a second portion 52a" which exits the base 38 and connects with a primary arm 65. The auxiliary tank 62 is connected at its bottom to a conventional overflow tube 66 which is conventionally connected with the bowl and which has been modified to receive an elbow 68 from the auxiliary tank. The bottom of the auxiliary tank 62 includes an auxiliary float stopper 70 seated with respect to the elbow 68 at a seat 68a formed therein in a manner similar with respect to the conventional float stopper 22c and the conventional flush feed 22b. A control rod 72 is pivotally mounted to the auxiliary tank 62 and exits the tank 14 at its rear through a gasketed hole in the tank situated higher than the fill height of the flush water 60. A secondary arm 74 is connected with the control rod external to the tank 14. A tertiary arm 76 is mounted to the control rod 72 internal to the auxiliary tank 62. A first flexible linkage 78, preferably a fine link chain, connects together the primary and secondary arms 65, 74. A second flexible linkage 80, also preferably a fine link chain, connects together the tertiary arm 76 and the auxiliary float stopper 70.
In operation, as shown in FIGS. 1, 3 and 6, when the foot pedal 50 is depressed, the primary arm 65 rotates, causing the secondary arm 74 to rotate, the tertiary arm 76 to rotate and the auxiliary float stopper 70 to separate from its seat 68a, whereupon the auxiliary flush water 64 in the auxiliary tank 62 passes through the elbow 68, into the overflow tube 66 and thereupon into the bowl 12, thereby replenishing the trap 24 with water. Entry holes 75 in the auxiliary tank 62, preferably located just at or just below the fill height of the tank flush water 60, allow tank flush water 60 to enter into the auxiliary tank relatively slowly as compared to the rate at which the auxiliary tank flush water 64 exits at the elbow 68, so that basically only the volume of water in the auxiliary tank (and what little also enters through the entry holes 75 during auxiliary flush water exiting) exits to fill the trap 24. New water will enter into the tank 14 and into the auxiliary tank 62 via the conventional tank water height sensing water inflow valve of the tank 14 until the preset fill height of flush water 60 in the tank is reached, whereupon both the tank and the auxiliary tank will be refilled with flush water, respectively.
It will be noted that the original trap water 34 will very quickly drain at the bowl valve 16 as soon as it is opened, so that by the time the auxiliary tank water 64 enters into the bowl 12, the bowl valve stopper 55 has been, or momentarily will be, sealingly reseated against the bowl valve seat 58. Accordingly, only a short depress time is needed with respect to the foot pedal 50 to effect an auxiliary flush cycle.
The remaining Figures show variations of the two flush modality toilet according to the present invention, wherein like numerals identify like functioning components to those described herein above.
FIG. 7A depicts a two flush modality toilet 10' wherein the urinal flush modality is electrically controlled, and wherein FIG. 7B depicts an exemplary electrical schematic therefor.
The bowl valve control 18' is composed of a first solenoid 82 connected with the base 38' and an actuator 82a that is pivotally connected to the actuation lever 54 to thereby selectively control the open and closed states of the bowl valve 16. The auxiliary flush control 20' is composed of a second solenoid 84 connected with the auxiliary tank 62' and an actuator 84a connected with the second flexible linkage 80' to thereby control operation of the auxiliary float stopper 70. A momentary push button switch 86 is mounted to the tank 14'. Wires 88 electrically connect the first and second solenoids 82, 84 to a source of low voltage electrical power 90, such as supplied by a transformer connected to a utility electrical supply having ground fault circuit protection. A delay control 92 controls the duration during which the first solenoid 82 actuates, during which time the trap water 34 drains out the bowl valve 16; thereafter, the delay control actuates the second solenoid 84 for a preset time, during which the auxiliary tank flush water 64 drains into the trap 24.
FIGS. 8 and 9 depict a two flush modality toilet 10" having an alternative tank structure for effecting the requisite limited amount of auxiliary flush water for the urinal flush modality. This structure may be used with either a manual or electrical urinal flush modality.
Rather than incorporate an auxiliary tank as recounted hereinabove, the tank flush water is, itself, used, but only to a limited depth. To accomplish this, the auxiliary flush control 20" has an overflow tube 66' is modified to accept connection with an auxiliary flush tube 94. The auxiliary flush tube 94 connects to the overflow tube 66' somewhat near the bottom of the tank 14" and emanates therefrom at an acute angle, then bends into a vertical orientation that is parallel with the overflow tube 66'. The end of the auxiliary flush tube 94 is provided with a stopper seat 95 for an auxiliary float stopper 96 to seal against. The auxiliary float stopper 96 is pivotally connected to the overflow tube 66' via a studded ring 98 mounted thereupon. The auxiliary float stopper 96 is connected with a second flexible linkage 80" which is in turn connected to a control rod 72'. As shown in FIG. 9, the height of the stopper seat 95 is located a predetermined distance beneath the preset fill height of the flush water in the tank 14" so that substantially the amount of water needed to fill the trap 24 is above the stopper seat 95 and exits the tank (inclusive of whatever new water enters into the tank via the conventional tank water height sensing water inflow valve during exiting of water through the auxiliary flush tube), more-or-less about one gallon of water. An example of a known product that could be used as an auxiliary float stopper (perhaps with some mortification) is a Touch Flush Assembly, product no. 628P of Lavelle Industries, Inc. of Burlington, Wis. 53105.
In operation, upon the auxiliary float stopper 96 being raised by pulling of the second flexible linkage 80", new water will enter into the tank 14" via the conventional tank water height sensing water inflow valve until the preset height of flush water in the tank is reached, whereupon the tank will be refilled.
It will be noted that the bowl valve control 18" depicted in FIG. 8 does not show a separate base 38, but rather incorporates a base-like structure directly into the bowl 12' of the toilet itself, inclusive of a bowl valve throat 45', a bowl valve seat 58', drain hole 42', drain cavity 44' and a passageway 46'. In this regard, the bowl valve seat 58' is an elastomeric material that has been sealably connected with the bowl 12' at an aperture 15' formed at the lowest point thereof. A separate base is preferred to effect retrofitting of existing toilets (see below), but is not required for the production of toilets incorporating a two flush modality, wherein the base is desirably formed into the toilet itself. A wax seal 35"' seals the bowl outlet 30 with respect to the drain 36.
FIGS. 10A and 10B depict a two flush modality toilet according to the present invention wherein the auxiliary flush control is operated independent from the foot pedal 50. The structure depicted in FIG. 10A is associated with the structure previously discussed relative to FIGS. 1 through 6, whereas the structure depicted in FIG. 10B is associated with the structure previously discussed with respect to FIGS. 8 and 9. It is to be understood that in manual operation, the user would first depress the foot pedal 50 to cause the bowl valve 16 to be in an open state whereby the liquid in the trap 24 drains out the bowl valve, and then would release the foot pedal to restore the bowl valve to the closed state whereby sealing of the bowl valve stopper to the bowl valve seat is effected (for electrical operation, a solenoid would effect the aforesaid movements), and then effect auxiliary flushing via movement of a push rod mounted to the tank, as described hereinbelow.
As shown in FIG. 10A, the auxiliary flush control 20"' has an auxiliary tank 62", wherein the top 105 of the tank 14"' has a hole 100 through which a push rod 102 is slidable. A lever 106 is pivotally connected with a bracket 104 that is attached to the auxiliary tank 62". The distal end 102a of the push rod 102 pivotally connects with one end of the lever 106 and an appropriate length flexible member 80"' connects with the other end of the lever 106. The flexible member 80"', in turn, connects with the auxiliary float stopper 70. A downward movement of the push rod results in an upward movement of the auxiliary float stopper, whereupon auxiliary flush water enters the bowl in the manner discussed hereinabove.
As shown in FIG. 10B, the auxiliary flush control 20"" has an auxiliary flush tube 94 and, as in FIG. 10A, the top 105' of the tank 14"" has a hole 100' and a push rod 102' that is slidable with respect thereto. A lever 106' is pivotally connected with a bracket 104' that is attached to the tank 14"". The distal end 102a' of the push rod 102' pivotally connects with one end of the lever 106' and an appropriate length flexible member 80"" connects with the other end of the lever 106'. The flexible member 80"", in turn, connects with the auxiliary float stopper 96. A downward movement of the push rod results in an upward movement of the auxiliary float stopper, whereupon auxiliary flush water enters the bowl in the manner discussed hereinabove.
It will be appreciated that a conventional toilet can be retrofitted to function with a two flush modality, wherein a bowl valve 16 is provided in the bowl by drilling thereinto an aperture 15 at the low point of the trap and providing a form fitting elastomeric bowl valve throat 45 with bowl valve seat 58, providing a bowl valve control 18, fitting a base 38 to the bottom of the toilet, and providing an auxiliary flush control 20. For example, the two flush modality toilet shown in FIG. 1 may be considered a depiction of such a retrofitted toilet.
To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. For example, either or both of the bowl valve seat and the bowl valve stopper may be composed of an elastomeric material or either may be selectively composed of another mutually sealing material or materials. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.
|
A two flush modality toilet composed of a bowl, a tank connected with the bowl wherein the tank is connected to a water supply, a conventional flush modality for flushing solid waste from the bowl, and a urinal flush modality for flushing liquid only waste from the bowl, wherein the urinal flush modality includes: a bowl valve at the base of the bowl, a bowl valve control for selecting between open and closed states of the bowl valve, a conduit for directing liquid waste from the bowl into the sanitary drain, and an auxiliary flush control for supplying a limited quantity of flush water from the tank into the bowl to provide restoration of the trap water in the bowl after a urinal flush modality has occurred. A foot pedal selectively operates the bowl valve, wherein when in an open state all the liquid in the bowl is drained. Upon release of the foot pedal, the bowl valve is returned to the closed state. Flush water from the tank is then delivered to the bowl to restore the trap water. Operation may be mechanically effected or electrically effected. With regard to mechanical operation, the flush water from the tank may be introduced by action of the foot pedal or by separate action of a control at the tank.
| 4
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of manufacturing high-purity polycrystalline silicon granules which is suited for use in a CZ process.
2. Description of the Background
As manufacturing methods of polycrystalline silicon, the Siemens process and the fluidized bed granulation process are available. According to the Seimens process, which is a type of chemical vapor deposition (CVD) process, chlorosilane in gaseous state is fed into a reactor, while heating by energization a thin silicon rod which is arranged in a bell jar reactor. The chlorosilane gas fed into the reactor forms silicon by thermal decomposition/hydrogen reduction, which is then deposited on the thin silicon rod, thereby effecting silicon growth. This method of manufacturing polycrystalline silicon is currently a mainstay, however, the method affords a low efficiency, being basically a batch system. In addition, this method is problematic because the silicon deposition surface area is small, as compared with the reactor capacity, and heat radiation from the bell jar reactor surface is large.
At present, a fluidized bed granulation process is being developed for the manufacture of polycrystalline silicon. According to the fluidized bed granulation process, as shown in FIG. 4, deposition of silicon is made on granular silicon particles 2 as the material in a cylindrical reactor 1 which is called fluidized bed reactor. Thus, this method is, in principle, a type of CVD process, similar to the Seimens process.
According to this method, the inside of reactor 1 is heated by outside heaters 3 and into reactor 1, are fed, from above, silicon particles and, from below, the material gas containing chlorosilane. The silicon particles 2 fed into reactor 1 form a fluidized bed with the reaction gas which is rising inside reactor 1. The material gas is heated by the heaters in the process of rising inside the reactor 1, thereby undergoing thermal decomposition/hydrogen reduction, yielding silicon, which is deposited on the surface of the silicon particles 2, which form the fluidized bed.
The fluidized bed granulation method of manufacturing polycrystalline silicon is a continuous system and the ratio of the silicon deposition surface area to the capacity of the reactor is drastically larger, as compared with that in the Seimens process. A notable advantage in productivity and power consumption is also obtained. Consequently, this enables a large reduction of manufacturing cost. Since the high purity polycrystalline silicon manufactured by the fluidized bed granulation process is granular, it will, in all likelihood, have applications such as the material for solar batteries, or as the charging material in manufacturing single crystalline silicon by the CZ process. Czochralski (CZ) process is a method of producing single crystals from molten material and is used to prepare silicon single crystals.
Important parameters in the fluidized bed granulation process include fluidized bed temperature, chlorosilane concentration in the material gas, material gas flow velocity, diameter of polycrystalline silicon particles, fluidized bed height and the time taken by silicon particles to pass through the fluidized bed, for example.
With regard to the material gas temperature, over-heating at the preheating stage will cause deposition; therefore the preheating temperature should be kept below 300° C.
The material gas temperature inside the reactor is controlled to about 900°-1,100° C. for prevention of silicon deposition on the reactor wall.
The chlorosilane concentration is controlled to about 20-50%, because at higher concentrations, fine powders are formed called fume, which brings about inter-particular cohesion.
The gas flow velocity is selected at 60-200 cm/sec, taking account of overall reaction efficiency, productivity and operational troubles.
The average diameter of fluidized particles, is preferably greater than 0.8 mm. If it is smaller than 0.5 mm, the flow rate of the gas parts where particles are dense, as specified by the minimum fluidizing velocity (Umf), so that even if the material gas feed rate is increased, it will tend to blow through as bubble gas. As a consequence, the silicon deposition velocity does not increase in proportion to the increasing amounts of the material fed. Thus, the average diameter of fluidized particles should desirably be higher than 0.8 mm, more preferably higher than 1 mm.
The dwell time or residence time of the reaction gas in the fluidized bed is empirically selected at about 0.5-2.0 sec. The dwell time is determined by dividing the height of the fluidized bed by the flow velocity of the material gas .
Under these conditions, the silicon deposition velocity is around 0.1 μm/min. It is at this level that the development of the fluidized bed granulation process is presently occurring.
The silicon deposition rate means the average deposition rate, G, which is obtained by dividing the volume increase rate of silicon by the total surface area of silicon particles. The volume increase rate is obtained by dividing the weight increase rate by the density ρ(2.33 g/cm 3 ) of silicon crystal. The total surface area, S, may be determined, for example, from the average particle size, d, by S=V(1-ε) . (6/d) or S =(W/ρ)·(6/d). Where V designates bulk volume of particle, W weight, and ε voids.
Despite the progress being made with the fluidized bed granulation process, it has recently been determined by the present inventor that about 50-200 ppm by weight of chlorine remains in the polycrystalline silicon manufactured under such condition. The residual chlorine is not only absorbed by the surface of the granules, but exists also in their interior in abundance. On this account, the residual chlorine can not effectively be removed by after-treatments such as a vacuum high temperature treatment, for example. If chlorine remains in the interior of the granules, as the granules are charged into molten silicon in a crucible, the chlorine inside the granules will expand; thereby scattering the molten silicon. As a result, adaptation of such a product to many processes, such as the CZ process, is not feasible.
Thus, a need continues to exist for a method of manufacturing high purity polycrystalline silicon granules, which granules have a greatly reduced residual chlorine content.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a process for manufacturing high-purity polycrystalline silicon granules, which have a greatly reduced amount of residual chlorine therein.
This object and others, which will become more apparent, are provided by a process for manufacturing high-purity polycrystalline silicon granules, which entails depositing silicon on the surface of high-purity silicon particles, while feeding into a fluidized bed at a high temperature a material gas consisting of high-purity chlorosilane and a diluting gas, wherein a silicon deposition rate in excess of about 0.4 μm/min. is effected.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a graph showing the relationship between the silicon deposition rate and the residual chlorine concentration.
FIG. 2 is a diagram showing a silicon deposition mechanism.
FIG. 3 is a graph showing the relationship between the residual chlorine concentration and the position in the fluidized bed.
FIG. 4 illustrates the fluidized bed granulation process.
FIG. 5 represents graphs which show the time dependent changes in respective gas compositions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The sources of the chlorine which remains in the high purity polycrystalline silicon granules manufactured by the fluidized bed granulation process is the chlorine content which is contained in the chlorosilane of the material gas. If so, the residual chlorine concentration may be considered to be governed by the chlorosilane concentration in the material gas. However, when the effect of chlorosilane concentration on residual chlorine concentration was examined by altering the former, no intimate correlation was found between them. Moreover, the effect of reaction temperature on residual chlorine concentration is very weak.
The present inventor has considered the residual chlorine concentrations in Si extracted from different parts of the fluidized bed reactor by neutron activation analysis. The reaction conditions are: particle size, 0.6-1.6 mm; flow velocity, 60-160 cm/sec; SiHCl 3 , used as chlorosilane; and the mol ratio of SiHCl 3 /H 2 , 1. The fluidized bed height is 1,500 mm (constant).
The result is shown in FIG. 3. From FIG. 3, it may be seen that the residual chlorine concentration is lower in the silicon extracted from the neighborhood of the gas blowing-in part of the fluidized bed than in the upper part of the fluidized bed corresponding to the downstream part of gas.
Considering this discovery in detail, it appears that the gas blown in from the lower part of the fluidized bed in the fluidized bed reactor is flowing in a state approaching the piston flow, when the diameters of the fluidized particles in the fluidized bed are larger than about 0.4 mm, so that in regions where the flow velocity is not excessively large ##EQU1## the fluidized bed reactor is in a state approaching that of an integrating type reactor. Hence, the silicon deposition rate and the residual chlorine concentration are different between the gas inlet part of the fluidized bed and the upper part of the fluidized bed where reaction has proceeded. From this, it was noticed that shortening the fluidized bed by cutting off the part corresponding to the downstream part surprisingly results in a lowered average value of residual chlorine concentration.
Then, the cause of change in the residual chlorine concentration along the route from the gas blowing-in part to the downstream part of gas was considered. Plotting the relationship between average deposition rate of silicon and residual chlorine concentration, concerning all experimental data, it was noticed that an intimate correlation exists between them, the residual chlorine concentration declining with increasing silicon deposition rate.
FIG. 1 plots the graph of this relationship. The experimental data contain those obtained with two types of reactors and with reaction temperature, chlorosilane gas concentration, height of fluidized bed, and particle diameter, for example, being varied. Under these conditions, the residual chlorine concentration strongly depends on the average deposition rate; the higher the rate, the lower the concentration. And when the average deposition rate is higher than 0.4 μm/min, the residual chlorine concentration is maintained below 20 ppm. In accordance with the present invention, it has been discovered that polycrystalline silicon granules in which the residual chlorine concentration is maintained below 20 ppm do not cause scattering of the silicon melt, even when they are adopted for process such as the CZ process.
By this token, according to the current fluidized bed granulation process, the silicon deposition rate is selected at around 0.1 μm/min; as a result of which, the residual chlorine concentration rises to up to 50-200 ppm by weight, causing violent scattering of the silicon melt.
The manufacturing method of the present invention enables manufacturing of high quality polycrystalline silicon with a low chlorine concentration which is suited for use in processes such as the for the CZ process by elevating the silicon deposition rate above about 0.4 μm/min.
In view of the above, a comprehensive description will now be provided of the necessary considerations for raising the deposition rate to higher than about 0 4 μm/min.
The silicon deposition rate G is given as a product of weight increase W and total surface area S:
G=W/ρS=W/WSv
where
ρ: Density of crystalline silicon (2.33 g/cm 3 )
Sv : Specific surface area of silicon particle
S=Sv·V·(1-ε FB )
where
V: Volume of fluidized bed
ε FB : Voids (0.5-0.7)
The weight increase rate W is given by the equation given below as a function of gas flow rate F and mol fraction X of chlorosilane:
W=ηF.sub.x M/Vn
where
Vn: Varies depending on temperature with regard to volume per 1 mol of gas
at 900° C., 96,250 cm 3 /mol
at 1,000° C., 104,450 cm 3 /mol
at 1,100° C., 112,650 cm 3 /mol
η: Proportion of silicon in material gas which is deposited
M: Atomic weight of silicon (28.08)
Accordingly, ##EQU2##
Thus the silicon deposition velocity is inversely proportional to S v t. where
t=V/F=L/u
L: Length of fluidized bed
u: Flow velocity of gas
S v : Specific surface area of particle when the particle is spherical,
S.sub.v =6/d
where
d: particle size
Therefore,
G oc d/t =du/L
To make G larger, it is effective to make the gas flow velocity u and particle size d larger, besides shortening the length L of the fluidized bed.
Having described the present invention, reference will now be made to certain Examples which are provided solely for illustration and are not intended to be limitative.
EXAMPLE 1
For example, when the reaction temperature =1,050° C., concentration of SiHCl 3 x=0.5 (H 2 balance), particle size d=1 mm, and flow velocity u=100 cm/s, the result will be G>0.4 mm/min for L<7cm. The dwell time at this time is t-0.07 s. An assumption of η=0.2 is made. See Kojima and Furusawa: Kagaku Kogaku (Chemical Engineering) Vol. 51 No. 3 P217-223 (1987)
However, if the dwell time t is extremely shortened, the material gas will pass through the bed, without reacting before approaching the equilibrium state, with a consequence of reduced silicon deposition proportion, η, resulting in lowered material utilization.
Accordingly, there exists an optimal range of dwell time t which meets these two requirements.
To further explain this relationship, in the silicon deposition method from the chlorosilane series (SiCl 4 , SiH 2 Cl 2 and SiH 3 Cl), the reaction of depositing silicon and the reaction of etching silicon compete with each other, so that there exists a state of thermodynamic equilibrium which is determined by such conditions as gas mol ratio expressed by Cl/H, temperature and pressure, etc.
See E. Sirtl, L. P. Hunt and D. H. Sawyer: J. Electrochem. Soc: SOLID-STATE SCIENCE AND TECHNOLOGY, Vol 121, No. 7 P919-925 (1974)
As the reaction proceeds, the system approaches this state of thermodynamic equilibrium. This velocity is determined by the type of chlorosilane , mol ratio, pressure and mass transfer rate relative to gas-solid contact, for example.
It was confirmed that as shown by FIGS. 5 (A)-(D), when the reaction temperature is higher than 900° C., mol concentration of chlorosilane 20-50% and average diameter of particles larger than 0.8 mm, with the SiHCl 3 --H 2 system, a state approaching to more than 90% of the aforementioned thermodynamic equilibrium state is brought about within a dwell time of about 0.10-0.30 sec and a state approaching to more than 95% thereof within about 0.13-0.40 sec. With the SiCl 4 --H 2 system, it was confirmed that a state approaching to more than 90% of the thermodynamic equilibrium state is brought about within a dwell time of about 0.20-0.50 sec, and to more than 95% within about 0.25-0.65 sec. Also, with the SiH 2 Cl 2 --H 2 system, it was determined that 90-95% is reached within the same order of dwell time.
As described above, the equilibrium state is rapidly approached by thermal decomposition and hydrogen reduction reaction of chlorosilane at temperatures higher than 900° C. Accordingly, on an assumption that use is made of a fluidized bed reactor having 1.5-2.5m fluidized bed height, under the condition of:
Reaction temperature=1,050° C.
H 2 /SiHCl 3 =1.0
Total pressure=1 atm
Diameter of particles=1.0 mm
Gas velocity=120 cm/sec (at 1,050° C.)
the silicon deposition reaction is nearly completed about 40-60 cm above the gas blowing-in port of the dispersion plate and a near equilibrium state part where silicon deposition barely takes place is formed at a region over 110-210 cm thereabove.
Accordingly, in order to increase the silicon deposition rate and reduce residual chlorine in silicon granules, it is proper to set the reaction conditions such that in the fluidized bed particle part there should exist no region which is in the thermodynamic equilibrium state or a state approaching it as at the upper part of the fluidized bed as previously mentioned.
Thus, when the mol ratio of H 2 /chlorosilane, average particle size of Si granules in the fluidized bed, flow velocity of material gas, etc., are identical, the amount of residual chlorine in the product silicon granules is smaller under the reaction condition of lower fluidized bed height or near equilibrium state being reduced than under the reaction condition of high bed or near-equilibrium region being large. However, if the fluidized bed height is extremely lowered, the percentage utilization of material gas will decline, with resultant lowered productivity.
In taking the balance between both extremes, it is desirable to cut off at least the part of the bed where the degree of attainment of thermodynamic equilibrium is higher than 90-95%. This means requiring the dwell time of the reaction gas in the fluidized bed to be less than 0.50 sec, or preferably, less than 0.30 sec.
The effect of reducing the residual chlorine concentration by cutting off the region being in a near thermodynamic equilibrium state in the fluidized bed particle part has the effect of having no region where the silicon deposition rate is low. Thus, decreasing the reaction rate by lowering the reaction temperature, to lengthen the time of reaching the thermodynamic equilibrium state, thereby reducing the region being in a near equilibrium state in the upper part of the fluidized bed, will bring about inverse effect.
With regard to the silicon deposition rate, it would appear at first that the larger this rate, the larger the residual chlorine. However, the inverse relation is observed instead. The reason appears to be as follows.
The formation of silicon from the chlorosilane gas/hydrogen system by way of CVD is believed to result from chemical and physical adsorption on the sites on the silicon surface of the intermediate product SiCl 2 which generates from chlorosilane gas (SiH 2 Cl 2 , SiHCl 3 and SiCl 4 ), followed by surface reaction (R1 and R2) of this adsorbed SiCl 2 with SiCl 2 (g) and H 2 (g) in the gas (FIG. 2).
SiCl 2 (adsorbed)+SiCl 2 (g) Si (solid)+SiCl 4 (g) . . . R1
SiCl 2 (adsorbed)+H 2 (g) Si (solid)+2HCl(g) . . . R2
The removal rate of Cl from SiCl 2 adsorbed on the silicon surface depends on the reaction rate of the reactions R1 and R2. While the ratio of reaction R1 to reaction R2 varies depending on the reaction conditions, when H 2 /TCS=1-4 and P total=1 atm, reaction R1 plays the predominant role. Thus, SiCl 2 attacks the SiCl 2 adsorbed on the surface of the silicon substrate 11, separating Cl 2 from the adsorbed SiCl 2 . In this way, by repeating the adsorption of SiCl 2 and removal of Cl 2 , only Si goes on being deposited on the silicon substrate 11.
However, the adsorption of SiCl 2 occurs in two ways, as described above, one being chemical and the other physical. The SiCl 2 physically adsorbed is moving on the surface of the silicon substrate 11. When the silicon deposition rate is slow, the attack on the physically adsorbed SiCl 2 is slight; therefore, the Cl remaining unremoved will move about for a long time on the surface of the silicon substrate 11. Since the silicon substrate 11 is polycrystalline silicon, there exists on the surface thereof pinholes, vacancies, etc., of crystal domain or on the atomic level, so that the SiCl 2 molecules which are moving about the surface fall into them, thus becoming immune to the attack. Further, even if they can be attacked, sometimes Cl 2 will not be removed on account of adverse access angle or orientation of the face. As a result, Cl will continue being deposited together with Si. Conversely, if the silicon deposition rate is rapid, the physically adsorbed SiCl 2 is immediately attacked, so that Cl may be rapidly removed.
The above-described reasoning may be qualitatively verified as follows:
The deposition rates of silicon and chlorine atoms per unit surface area of silicon granules are given by the undermentioned equations:
Nsi=cθt.sub.si -1
Ncl=2cθt.sub.cl -1
Where
c: Number of adsorption site of SiCl 2 per unit surface area
θ: Proportion of the number of sites having SiCl 2 actually adsorbed thereon to the aforementioned number
t si : Average value of the time before one molecule of SiCl 2 is attacked by the gas molecule, after it has been adsorbed by the granule surface
t cl : Average value of the time before one molecule of SiCl 2 falls into a pinhole or vacancy, etc., on the granule surface, after it has been adsorbed by the surface. According to the kinetic theory of gases: ##EQU3## where Pi: Partial pressure of the i-th component of the material gas
Mi: Molecular weight of the i-th component of the material gas
94 : Reacting cross-section of SiCl 2
N A : Avogadro constant (6.022×10 23 mol -1 )
R: Gas constant (8.314 J mol -1 K -1 )
T: Absolute temperature of material gas
Which temperature is constant, C, θ and t cl are all considered to be constant; therefore N cl is constant.
On the other hand, as the partial pressure of any one of components has increased, t si will be retrenched and N si becomes larger. The silicon deposition rate G=N si /N v follows suit. N v designates the number of silicon atoms (5.00×10 22 atoms/cc) in unit volume. That:
N.sub.cl =N.sub.si Cl=N.sub.v G[Cl]
is constant means that the chlorine concentration [Cl]is inversely proportional to the silicon deposition rate G.
FIG. 3 suggests that the residual chlorine concentration differs greatly between the gas blowing-in part and the downstream part of gas. However, as the average [Cl] is taken of the residual chlorine concentration all over the fluidized bed, followed equations are derived: ##EQU4## thus, attesting to the validity of N cl =N v G[Cl]·V signifies volume of the fluidized bed.
The value of N cl was found to be 4.6×10 11 cm -1 S -1 or 2.8×10 13 cm -2 min -1 in embodiments of this invention.
In the Siemens process heretofore practiced, there has been found almost no chlorine remaining. This is also attributable to high silicon deposition rate.
Tables 1-3 list results of application of this invention, as contrasted with comparative examples:
TABLE 1______________________________________ Compar- ative exam- Examples of this invention ple(s) TEST- TEST- TEST- TEST- TEST-11 12 13 14 15______________________________________Fluidized bed 1050 1050 1050 1050temperature (°C.)SiHCl.sub.3 /H.sub.2 0.1 1 1 2Average diameter 0.5 1.5 0.8 0.8 0.8of particles (mm)Flow velocity 80 150 110 140 110(cm/s)Fluidized bed 120 90 90 90 90height (cm)Average deposition 0.1 0.7 0.4 0.5 0.6rate (μm/min)Residual chlorine 120 10 20 12 12concentration(ppm wt)______________________________________
TABLE 2______________________________________ Comparative Examples of example(s) this invention TEST- TEST- TEST- TEST- TEST- 21 22 23 24 25______________________________________Fluidized bed 950 1050 1050 1100 1100temperature (°C.)SiHCl.sub.3 /H.sub.2 1 0.05 1 1 1Average diameter 0.8 0.8 0.8 0.8 1.0of particles (mm)Flow velocity 70 70 70 110 110(cm/s)Fluidized bed 30 30 30 50 80height (cm)Average deposition 0.2 0.06 0.4 0.5 0.5rate (μm/min)Residual chlorine 30 160 18 16 17concentration(ppm wt)______________________________________
TABLE 3__________________________________________________________________________ Compara- tive Comparative example (s) Examples of this invention example (s) TEST-31 TEST-32 TEST-33 TEST-34 TEST-35 TEST-36 TEST-37__________________________________________________________________________Fluidized bed temperature (°C.) 1050 1050 1050 1000 1050 900 900SiHCl.sub.3 /H.sub.2 1 1 1 1 1 1 1Diameter of fluidized bed 0.5˜2 0.5˜2 0.5˜2 0.5˜2 0.7˜2 0.5˜2 0.5˜2paricles (m/m)Flow velocity (cm/s) 80 80 160 100 150 100 80Fluidized bed height (cm) 180 50 100 50 100 150 180Total pressure (atm) 1 1 1 1 1 1 1Average deposition rate (μm/min) 0.06 0.5 0.4 0.6 0.6 0.08 0.05Residual chlorine concentration 150 14 18 10 12 110 180(ppmwt) ##STR1## 3˜5 0.2˜0.5 0.1˜0.4 0.1˜0.3 0.2˜0.5 0.1˜0.3 1˜1.5__________________________________________________________________________ *.sup.1) Near equilibrium region: Bed part where the degree of reaching the thermodynamicequilibrium is higher than 90% Si Depositing region: Bed part where the degree of reaching the thermodynamic equilibrium is not higher than 90%.
Tables 1 through 3 list test results obtained with a reactor tube of 100 mm ID and 1,800 mm height using a dispersion plate of single orifice type.
In TEST-11, the manufacture of polycrystalline silicon is made on a general condition setting for the current fluidized bed granulation process. The silicon deposition rate is as low as 0.1 μm/min and the residual chlorine concentration has reached 120 ppm by weight. In contrast in TESTS 12-15, a silicon deposition rate higher than 0.4 μm/min is ensured and the residual chlorine content is kept below 20 ppm by weight through adjustments of various conditions.
Similar results were obtained also in TESTS 21-25.
In TEST 31, manufacture of polycrystalline silicon was made under conditions of H 2 /SiHCl 3 =1, temperature 1,050° C., bed height 180 cm and flow velocity 80 cm/sec. The reaction has been attained to more than nearly 90% of the equilibrium around 35 cm above the dispersion plate, the part over 150 cm thereabove forming a very small deposition rate region where Si deposition rate is low. In the silicon granules manufactured under the above-mentioned conditions, 150 ppm by weight of residual chlorine was found, as measured by neutron activation analysis.
In contrast, in TEST-32, the reaction conditions are set at H 2 /SiHCl 3 =1, temperature=1,050° C., bed height 50 cm, and flow velocity 80 cm/sec. Under these conditions, where the reaction region being in a state of near thermodynamic equilibrium is cut off, unlike in TEST-31, the residual chlorine concentration in the silicon granules has been reduced down to 14 ppm by weight.
While TEST-32, the thermodynamic equilibrium region was eliminated by directly lowering the bed height, similar effect may be achieved by increasing the flow velocity. This is illustrated by TEST-33.
Selected as the reaction conditions are H 2 /SiHCl 3 - 1, temperature=1,050° C., bed height=100 cm and flow velocity 160 cm/sec. The reaction has nearly completed around 85 cm above the dispersion plate, only 18 ppm by weight of residual chlorine being measured in the silicon granules obtained under the above-mentioned conditions.
In TESTS-34-35 also, the residual chlorine is very small.
TESTS-36 and -37 present examples of removing the equilibrium region by lowering the reaction rate. In both cases, the silicon deposition rate is low, with the residual chlorine concentration high.
For example, in TEST-36, the condition setting is made to H 2 /SiHCl 3 =1, temperature=900° C., bed height =150 cm and flow velocity=100 cm/sec. The silicon depositing reaction has been completed near 120-130 cm above the dispersion plate and the region where the equilibrium state has been reached is over about 20-30 cm, but 110 ppm by weight of residual chlorine exists in the silicon granules produced under the above-mentioned conditions for trial.
Note that in the above-described Examples, SiHcl 3 is used as chlorosilane, but SiCh 4 , SiH 2 Cl 2 or SiH 3 Cl may be used, or further, any mixture of them may be used. Besides, the dilution gas to be combined with chlorosilane is not restricted to H 2 which is used in the above-mentioned Examples, but as such as gas, Are, He, N 2 or the like may be employed singly or in combination.
Having described the present invention, it will be apparent to one skilled in the art that many changes and modifications may be made to the embodiments disclosed while remaining within the scope and spirit of the present invention.
|
A method of manufacturing high-purity silicon crystals, which comprises depositing silicon on the surface of high-purity silicon particles, while feeding into a fluidized bed reactor at a high temperature a material gas consisting of high purity chlorosilane and a diluting gas, said method having a silicon deposition rate in excess of about 0.4 μm/min.
| 2
|
BACKGROUND
The present application relates to a method for cutting a fish head off a fish, i.e., heading a fish, and in particular, a method for orienting a fish in a heading machine for heading. The present application also relates to a device for orienting a fish in a heading machine, in which a blade suitable for heading a fish is provided.
An underlying issue of heading a fish using a heading machine is solving the problem of removing the entire fish head without removing usable fish meat from the fish body. An array of suggestions have been proposed regarding positioning the fish such that a blade plane spanned by a cutting blade runs precisely between the fish body and the fish head. For example, a suggestion has been made to create a form fit between a fish head and a positioning unit. Pointed objects, such as nails or needles, are attached to the positioning unit. These pointed objects penetrate into a thin flesh cover of the fish head. Through a comparatively complex displacement mechanism, with the aid of which a positioning unit is lowered in a direction toward the fish's head, the pointed objects are pressed into the flesh. In this manner, the fish is coupled to the positioning unit. The positioning unit must then be controlled in a constructively complex carousel unit so that the fish body is displaced in a trough in which it is conveyed in a direction toward the positioning unit and then transported out of it.
While the devices described above are capable of positioning a fish in the desired position such that the fish may be headed, these devices are very costly and therefore fail to consider the demands placed on modern fish processing machines.
SUMMARY
The following summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
As described in the present application, a method and a device is presented that uses comparatively little operative outlay to precisely position a fish such that the fish may be headed along a desired cutting plane. In one embodiment, a method is disclosed that applies a displaceable pressure part to act on an area of the fish's head, thereby displacing the fish's head in a direction toward the fish's body. Yielding to this pressure, the fish is displaced into a position suitable for heading.
In another embodiment, a device is presented that utilizes a pressure part that may be lowered onto a rising area of the fish's head. The pressure part has a surface that is applied to the rising area of the fish's head. The fish is displaceable on a substrate as the pressure part is lowered.
Embodiments described herein advantageously dispense with the complex formfitting and coupling of the fish's head to a positioning unit, as previously described. Rather, the pressure part of the embodiments described herein utilizes the fact that a fish has a very smooth surface, both in regard to its shape as well as its scale covering with which the fish lies on a substrate. Through selectively applying pressure to a part of the fish, the fish moves in a desirable direction for positioning purposes. The fish is stopped in a position suitable for heading via the fish's fins or gills catching on device positioned proximate to the fish.
Through the use of a fish's natural composition, a comparatively light pressure part may be used for positioning the fish for heading. The pressure part may be controlled with the aid of a light control device to exert a pressure suitable for positioning the fish for heading. Moreover, the pressure part may be moved rapidly after executing a positioning procedure, such that it is again available in its starting position for positioning another fish.
In one embodiment, the pressure part is displaced in a vertical direction. Through this displacement in the vertical direction, relatively little space is required to position a fish. In addition, through the vertical displacement of the pressure part, an adequate pressure may be exerted on an appropriately formed area of the fish's head, resulting in desired positioning of the fish under the effect of the pressure.
The pressure part may also be displaced in a horizontal direction. By allowing horizontal displacement, the pressure part may follow the fish as it moves resulting from the pressure effect exerted on the fish's head until the fish has slipped into its final position.
The pressure part acts on the rising area of the fish's head using an inclined pressure surface. The incline of the pressure part corresponds approximately to that of the rising area of the fish's head. The inclined pressure surface, acting on the rising area of the fish's head, aids in proper displacement/positioning of the fish.
In one embodiment, the fish is placed in the heading machine lying in a lateral position. Pressure is exerted on an area of the fish's head which rises according to the lateral position of the fish. Through this lateral position, the fish is in a stable position as the pressure is exerted thereon, so that a secure introduction of the pressure on the appropriate area of the fish's head may be expected.
The fish is guided in a trough on which it is laid when it is placed on the heading machine. During the action of the pressure part, a side edge of the trough determines the displacement direction in which the fish is brought into the desired heading position.
The pressure part is applied to the fish in a direction toward the side edge of the trough. The edge, therefore, provides a solid support for guiding the fish into the desired heading position.
The pressure part is applied to the fish to move it in the direction toward the trough's side edge and also in the direction of the fish's tail. A fish is generally inclined both in a longitudinal direction and also transversely to the longitudinal direction of the fish such that pressure, in one or both directions may be applied to the fish. In one embodiment, the pressure surface of the pressure part is positioned diagonally to edges of the pressure part, in which the pressure surface is inclined not only in the longitudinal direction of the fish body, but also transversely to the longitudinal direction of the fish body. In this arrangement, when the pressure part is lowered toward the fish body, the pressure part influences the fish body both in its longitudinal direction and also transversely to its longitudinal direction.
Because the pressure surface of the pressure part is inclined in two directions, it acts to displace the fish both in the longitudinal direction of the fish and also transversely to the longitudinal direction of the fish. By selecting an appropriate area of the fish body to which pressure is applied when the pressure part is lowered, the fish is displaced into the desired heading position, even when slight pressure is applied.
As previously noted, the fish is pressed by the pressure part against a side edge delimiting a trough, in which the fish is laid for the purpose of heading. The trough defines the direction that the fish is displaced/positioned, such that the fish lying in the trough is oriented in relation to the cutting plane for heading.
The fish may be stopped during displacement/positioning by a braking device which, in one embodiment, engages the fish under a lateral fin. Braking devices that engage a lateral fin are useful to adequately position of the fish for heading.
The pressure part may be controlled by a four-bar chain. A four-bar chain is capable of performing control procedures in multiple planes. In addition, it is comparatively light and may be easily controlled by disk cams.
As will be described further in the Detailed Description below, a first part of a four-bar chain which controls horizontal movement of the pressure part may be connected via a coupling joint to a second part of the four-bar chain which controls vertical movements of the pressure part. The control in the horizontal and vertical planes may be performed easily and securely with the aid of the four-bar chain.
The first and second parts of the four-bar chain can be mounted independently of one another in pivot joints, each of which is attached to a support. In this way, the four-bar chain receives a secure suspension which allows reliable continuous operation of the entire device.
The first and second parts of the four-bar chain may each be pivoted around pivot axes of the pivot joints, which can run in vertical planes parallel to one another, of which each may run at an angle of 40 to 70° to a vertical plane spanned by the trough edge. Thus, the four-bar chain is operated in a position pivoted in relation to the trough edge. Through this pivoting of the four-bar chain and the distribution of the pivot bearings provided in the four-bar chain, a guide curve to be executed by the pressure part may have its course influenced to a wide extent. During execution of an operating cycle, it is desirable to guide the pressure part along a guide curve in which the pressure part is guided with angular velocities that are as constant as possible.
In one embodiment, the vertical planes spanned by the pivot axes may run at an angle of 50 to 60° to the vertical plane spanned by the trough edge. With an arrangement of a four-bar chain of this type, a guide curve results whose planar component passes harmonically into a curved component.
The pressure part may be guided by the four-bar chain at a constant distance from the trough edge. In this way, during positioning the fish only has forces applied to it in the displacement direction.
In one embodiment, the pressure part may be guided at a distance of 10 to 40 mm parallel to the edge. This distance of 10 to 40 mm may help avoid deformation of the fish even under the influence of forces acting transversely to the displacement/positioning direction.
In another embodiment, the four-bar chain is controlled by disk cams. A controller of this type has an advantage that control curves may be situated on the disk cams, with the aid of which the control procedure may largely be influenced in a predefined way, for example, to have the most uniform possible angular velocities.
Still further, the four-bar chain may be moved by an external control curve of the disk cam to control the horizontal movements of the pressure part.
The four-bar chain may be moved by an internal control curve of the disk cam to control the vertical movements of the pressure part. In this way, different control curves can be situated in one disk cam, so that all movements of the four-bar chain may be controlled by a single disk cam.
As previously noted, in one embodiment, the pressure part is controlled in the direction of the trough edge and transversely to the direction of the edge by an internal and external control curve. Through these uniform control curves, the constructive complexity for executing the control in the horizontal plane may be kept small.
The control movements of the disk cam may be transmitted to the four-bar chain by cams guided on the control curves. These cams allow sensitive scanning of the control curve, so that even sensitive parts of a control curve, for example, upon the transition from the planar part of the control curve to its curved part, may be traveled precisely.
In this particular embodiment, the four-bar chain is lowered by its second part in the direction toward the fish body, and the pressure part is pressed thereon by an extension spring. Thus, with the aid of the extension spring, an approximately constant contact pressure force is exerted on the fish, largely independently of its dimensions.
The pressure part is provided on an angled end, running parallel to the trough edge, of a lower strut of the four-bar chain running in a horizontal direction. Through this parallel orientation of the angled end to the edge, a parallel guide of the pressure part along the edge may be ensured, although this edge may be moved during the orientation of the fish as a conveyance device on which the troughs are situated moves the troughs in a conveyance direction.
An action center of the pressure part applied to the fish's head may be moved on a guide curve which runs in a plane in a lowered state of the pressure part and runs curved in a raised state of the pressure part. Such a guide curve allows nearly uniform distribution of the angular velocities of the pressure part over the entire course of the guide curve. Insignificantly increased angular velocities may arise in the curved part of the guide curve in relation to the planar course of the guide curve. The difference of the angular velocities is generally slight, however, so that significant accelerations and/or delays do not occur in the area of the control elements, such as the control cam. Rather, the angular velocities may rise upon the transition from the planar area of the guide curve into the curved part and increase approximately up to the middle of the curved part. The angular velocities are then reduced again in the direction toward the deflection of the guide curve in the direction toward the planar part, in which the angular velocities are constant.
The disk cam may be mounted on a drive axis that runs parallel to the pivot axes of the pivot joint. In this way, the cams guided on the control curves of the disk cam may sensitively scan the control curve without forces acting on the control curves that are greater in some areas than others.
In a device for orienting a fish body in a heading machine, in which a blade suitable for cutting a fish head off of a fish body is provided, the control curves on one side and the four-bar chain on the other side may run in first set of planes that are parallel to one another, and which run diagonally to a second set of planes plane spanned by the edge of the trough. Through these planes running diagonally to one another, it is possible to determine a guide curve for the pressure part in which the angular velocities of the pressure part are distributed largely uniformly over the entire guide curve.
The pressure part may have a higher conveyance speed in the area of the curved part of the guide curve than in the planar part of the guide curve. The particular velocity is controlled in accordance with an arrangement of pivot joints in the four-bar chain in the diagonal position of the two planes to one another. In this way, the individual variables that influence the guide curve are set sensitively, which ensures that high accelerations of the pressure part in the area of the guide curve are generally avoided.
DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 shows a perspective illustration of a fish heading machine,
FIG. 2 shows a front-side view of the fish heading machine,
FIG. 3 shows a top view of the fish heading machine,
FIG. 4 shows a rear view of the fish heading machine in a perspective illustration,
FIG. 5 shows an enlarged illustration of a control unit corresponding to a detail area identified in FIG. 4 ,
FIG. 6 shows a side view of the fish heading machine,
FIG. 7 shows an enlargement of the control device corresponding to a detail area identified in FIG. 6 ,
FIGS. 8A and 8B show cross-sections of the fish heading machine,
FIG. 9 shows an enlarged view of the fish heading machine in the area of the controller,
FIGS. 10A and 10B show perspective illustrations of a controller in the direction of a drive axis which drives the disk cams,
FIG. 11 shows an enlarged view of a controller transverse to the plane spanned by the four-bar chain, and
FIG. 12 shows a further enlarged view of a detail area identified in FIG. 11 of a guide curve to be executed by the pressure part.
DETAILED DESCRIPTION
As shown in FIGS. 1-12 , a fish heading machine 1 comprises a machine frame 2 , a conveyor 3 , a control device 4 , and a cutting blade 5 which is driven by drive 6 . The conveyor 3 , having an upper belt 7 and a lower belt 8 , is guided in the machine frame 2 . Troughs 9 , in which fish 10 are placed for heading, are attached to the conveyor neighboring one another. As shown, each trough 9 is divided by a partition line 11 into a head receptacle 12 and a carcass receptacle 13 . The fish's head 14 lies in the head receptacle 12 , while a fish's body 15 rests in the carcass receptacle 13 on the other side of the partition line 11 . The fish's tail 16 adjoins the fish's body 15 in the longitudinal direction of the fish 10 .
Each fish 10 rests on its side in such a way that its back 17 presses against an edge 18 delimiting the trough 9 . More particularly, the edge 18 delimits the trough 9 transversely to a conveyance direction 19 of the conveyor 3 , with the edge 18 delineating the rear of the trough 9 in respect to the conveyor direction 19 .
The cutting blade 5 is implemented as a circular blade driven by the drive 6 , and is situated in a plane spanned by the partition line 11 . A fish's head 14 is cut off of the fish body 10 with the aid of this cutting blade 5 . For this purpose, a fish 10 is oriented within a trough 9 in such a way that the fish's head 14 is cut off of the fish's body 15 at a point which lies directly in front of a fin 20 on the fish's body. For orientation, the fish 10 is moved with the trough 9 by application of pressure from a pressure part 21 until the fin 20 catches in a braking device 22 , which is attached to a lever 24 pivotable around a transverse axis 23 . This lever 24 extends above the fish 10 in the conveyor direction 19 .
The pressure part 21 is implemented as a two-arm lever mounted so it is pivotable around a pivot point 25 . The pressure part 21 includes a pressure surface 26 that is applied to an area 27 of the fish's head 14 rising in the direction toward the fish's body 15 . For this purpose, the pressure surface 26 is provided with a first incline 28 . This first incline essentially corresponds to the incline of the rising area 27 of the fish's head.
Pressure is exerted by the pressure surface 26 on the rising area 27 of the fish's head 14 . The pressure surface 26 is dimensioned as sufficiently large to displace the fish 10 in its trough 9 in the direction toward the fish's tail 16 . The pressure applied by the pressure surface 26 is generated with the aid of an extension spring 29 , which pulls the pressure part 21 , implemented as a dual-arm lever, on the other side of the pivot point 25 in the direction toward a coupling point 30 and, at the same time, presses the pressure surface 26 downward onto the rising area 27 of the fish's head 14 .
To orient the fish 10 along the edge 18 , the pressure surface 26 also has, in addition to the first incline 28 tailored to the fish head's rising area 27 , a second incline 31 , which is applied to an area 32 of the fish's head 14 , the second incline 31 rising transversely to the longitudinal axis of the fish 10 . Through this second incline 31 of the pressure surface 26 , the fish 10 is impinged in the direction toward the edge 18 , against which the back 17 of the fish 10 presses. In this way, the fish 10 is displaced in the direction toward its tail 16 because of the pressure along the edge 18 exerted by the first incline 28 . The fish's movement within the trough 9 ends when the fish's fin 20 is caught within the braking device 22 which halts the movement of the fish 10 .
Once positioned by applying pressure on the fish 10 with the pressure surface 26 , the fish 10 , lying in the trough 9 , is transported by the conveyor 3 in the direction 19 toward the cutting blade 5 , which cuts the fish's head 14 off of the fish's body 15 in the area of the partition line 11 . While the fish's head 14 falls out of the head receptacle 12 into a collection container (not shown) after it is cut off, the fish's body 15 is transported further in its trough 9 until it falls out of the trough upon the deflection of the upper belt 7 in the direction toward the lower belt 8 and is also collected in a container (not shown).
During the conveyance of the fish 10 in the direction toward the cutting blade 5 , the pressure part 21 may track the moving fish. In this case, the fish 10 moves both in the conveyor direction 19 of the conveyor 3 and also within its trough 9 . These movements of the fish 10 occurring in the horizontal plane should be tracked by the pressure part 21 . In addition, the pressure part 21 should also be deflected in this movement direction as soon as the fish 10 has reached the cutting blade 5 and is adjusted thereby into its particular position. In this instant, the pressure part 21 is raised in the vertical direction from the fish 10 under the cutting blade 5 , and is moved backward against the conveyor direction 19 of the conveyor 3 to the following trough 9 . There, the above sequence is repeated: the pressure part 21 is lowered onto the head 14 of the fish 10 lying in the trough 9 ; pressure is applied to the fish 10 via the pressure part 21 such that the fish 10 is positioned for heading; and the fish 10 is transported to the cutting blade 5 . Positioning the fish 10 ends as soon as the fish, lying in the trough 9 , has reached the cutting blade 5 .
The pressure part 21 is controlled by a four-bar chain 34 . This four-bar chain 34 essentially comprises struts 35 , 36 , 37 , and 38 , each two of which are connected to one another via joints 39 and 40 . In this case, the two struts 35 , 36 form a first part 41 of the four-bar chain 34 , connected via pivot joint 39 . Struts 37 , 38 form a second part 42 of the four-bar chain 34 , connected via pivot joint 40 . The first part 41 is connected to the second part 42 via a coupling joint 43 .
The first part 41 is mounted in a pivot joint 44 so it is pivotable, while the second part is mounted in a second pivot joint 45 so it is pivotable. The first pivot joint 44 and the second pivot joint 45 are attached to a support 46 , which is connected to the machine frame 42 .
The strut 36 of the first part 41 of the four-bar chain 34 executes movements in the horizontal plane, while the strut 37 of the second part 42 executes movements in the vertical direction. If horizontal movements executed by the strut 36 are superimposed on vertical movements transmitted by the strut 37 , movement sequences both in the horizontal and also in the vertical planes arise in an angled end 47 of the four-bar chain 34 attached to the strut 36 . In this case, the movements are controlled both in the vertical and also in the horizontal plane by a disk cam 48 , in which an internal control curve 49 and an external control curve 50 are impressed. The external control curve 50 is connected via a first control cam 51 to the strut 35 of the first part 41 , so that the strut 34 follows the movements which the control cam 51 scans on the outer control curve 50 .
In a similar way, a control cam 52 connected to the strut 38 of the second part 42 is guided on the internal control curve 49 . The control cam 52 and thus also the strut 38 are raised or lowered in accordance with this internal control curve 49 . Therefore, the angled end 47 of the strut 36 is also raised or lowered in the same rhythm. The rhythm of the raising and lowering and also the rhythm of the movements of the first part 41 in the horizontal direction are predefined in this case by the speed of the disk cam 48 . This is mounted on a drive axis 53 so it is rotatable. The control curves 49 , 50 are also defined in relation to this drive axis 53 . The disk cam 58 is driven by a gear 54 , which is synchronized with a drive (not shown) of the conveyor 3 , so that the movements of the angled end 47 controlled by the control curves 49 , 50 are tailored to the movements of the troughs 9 on the conveyor 3 . In this case, a guide curve 56 , on which an active point 55 and therefore the entire pressure part 21 may be guided at the most uniform possible angular velocities, is desired for the pressure part 21 and/or the active point 55 assumed in the pressure surface 36 . This guide curve has a planar part 57 , along which the pressure part 21 is guided in the lowered state and is applied to an appropriate area 27 , 32 of the fish 10 .
A curved part 58 of the guide curve 56 rises above the planar part 57 , along which the pressure part 21 is guided back again to a fish 10 lying in the next trough 9 . The pressure part 21 is then lowered again to this fish 10 lying in the following trough 9 , so that it is applied to the fish 10 lying in this trough 9 along the planar part 57 in a position in which the fish's head 14 may be cut off of the fish's body 15 . In this case, the guide curve 56 is guided in a counterclockwise rotational direction 59 on the guide curve 56 . The pressure part 21 tracks the fish 10 lying in the trough 9 in the conveyor direction 19 of the conveyor 3 and the fish 10 is displaced simultaneously both in its longitudinal direction in the direction toward its tail part 16 and also transversely to its longitudinal direction in the direction toward the edge 18 .
After the fish 10 has arrived in the area of the cutting blade 54 , the pressure part 21 is raised by lifting the pressure surface 26 from the fish 10 , and is simultaneously displaced along the curved part 58 in the direction toward a fish 10 lying in a following trough 9 . In this case, due to the shape of the guide curve 56 , the pressure part 21 is transported along this guide curve 56 at an essentially uniform angular velocity, so that slight accelerations only occur in a rising part 60 of the guide curve up to its uppermost point 61 , and delays during transport of the pressure part 21 occur in an adjoining falling part 62 up to the reentry into the planar part 57 of the guide curve.
The control procedures in the area of the four-bar chain 34 also occur in accordance with this largely uniform distribution of angular velocities within the guide curve 56 , so that as the control curves 49 , 50 are traveled by the control cams 51 , 52 in the individual phases which the pressure part 21 passes through, only slight accelerations or delays occur. The wear of both the control cams 51 and 52 , and the control curves 49 and 50 , is thus held in narrow limits and is largely negligible if appropriate materials are selected.
The guide curve 56 results on the basis of an array of constructive measures which are tailored to one another. Thus, for example, the pivot movements of the struts 35 , 36 , 37 , and 38 run in planes which are plane parallel to one another, and which run at an angle of 40 to 70° to a plane spanned by the edge 18 . The control curves 49 , 50 and therefore also the movements of the control cams 51 and 52 also run plane parallel to the pivot planes of the struts 35 , 36 , 37 , and 38 .
The axes at the pivot joint 44 and 45 run perpendicularly to these pivot planes in which the struts 35 , 36 , 37 , and 38 are pivoted, which thus run parallel to the drive axis 53 of the disk cam. In addition, the axes of the joints 39 , 40 , and 43 also run parallel to these axes.
The angled part 47 is angled in relation to the strut 36 in a direction which runs parallel to the edge 18 . The pressure part 21 connected to the angled part 47 is thus guided parallel to the trough 9 by the pivot movements which the first part 41 of the four-bar chain 34 executes. Through the synchronization of the movements in the area of the disk cam 48 with the movements of the trough 9 in the conveyor direction 19 , the pressure part 21 acts in the planar part 57 of the guide curve on the fish 10 lying in the trough 9 using the pressure already described, and thus positions the fish 10 within the trough 9 during this action time in such a way that the cutting blade 5 may cut the fish's head 14 off of the fish's body 15 .
While the cutting blade 5 cuts the fish's head 14 off of the fish's body 15 , the pressure part 21 is transported back to the head of the fish 10 lying in the following trough 9 as the angled part 47 is simultaneously pivoted back and raised.
The guide curve 56 is predefined by the implementation of the individual struts 35 , 36 , 37 , and 38 . The lengths of the individual struts 35 , 36 , 37 , and 38 lying between the individual joins 44 , 39 , 43 , 40 , and 45 also particularly play a decisive role.
The orientation of a fish 10 for the purpose of heading with the aid of a cutting blade 5 is represented as follows.
A fish 10 is laid into one of the troughs 9 which are moved by the conveyor 3 in the conveyor direction 19 in such a way that the fish's body 15 lies in the carcass receptacle 13 and the fish's head 14 lies in the head receptacle 12 . The fish 10 lying in the trough 9 is then transported in the direction toward the cutting blade 5 . At the same time, the pressure surface 26 of the pressure part 21 is lowered to the rising area 27 and 32 of the head part 14 . This pressure surface 26 has a first inclination 28 for exerting a pressure in the longitudinal direction of the fish 10 and a second inclination 31 transverse to the longitudinal axis of the fish 10 . The pressure surface 26 , which runs diagonally to the main axes of the pressure part 21 , is applied to an area of the fish's head 14 which is also inclined to the fish's longitudinal axis and also inclined transversely to the fish's longitudinal axis.
By lowering the pressure surface 26 onto the corresponding area of the fish's head 14 , a force is exerted on the fish 10 under which the fish 10 is displaced both in the direction of the longitudinal axis of the trough 9 and also transversely to its longitudinal axis. In this case, the fish 10 presses against the edge 18 of the trough 9 .
The pressure part 21 tracks the movements of the trough 9 as it is conveyed on the conveyor 3 . For this purpose, the pressure part 21 is attached to the angled end 47 of the four-bar chain 34 . This four-bar chain 34 is driven by two control cams 51 and 52 guided on control curves 49 and 50 of the disk cam 48 , one of which is connected to the first part 41 of the four-bar chain 34 and the second of which is connected to the second part 42 of the four-bar chain 34 . The disk cam 48 is driven in synchronization with the conveyor 3 , so that the pressure part 21 tracks each trough 9 moved by the conveyor 3 and is returned again to the following trough 9 after reaching the cutting blade 5 . The guide curve 56 assists the tracking and return to a following trough 9 using a planar part 57 and a curved part 58 . In accordance with the planar part 57 , the pressure part 21 is conveyed parallel to the edge 18 in its lowered state, so that it is applied to the fish 10 in the area of the planar part 57 . After reaching the cutting blade 5 , the pressure part 21 is raised from the fish 10 and transported to the fish's head 14 lying in the following trough 9 . In this case, the pressure part 21 maintains largely uniform angular velocities both in the planar part 57 and also in the curved part 58 .
While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.
|
A method and device for positioning a fish is presented. In an exemplary method, a fish is positioned in relation to a cutting plane. Pressure is applied to a rising area of the fish's head via a pressure part such that the fish is displaced in the direction of the fish's body, thereby positioning the fish for heading. Thereafter, the fish is headed. In another embodiment, an exemplary device for positioning a fish in a heading machine comprises a pressure part having a pressure surface configured to be lowered onto to a surface area of the fish that is rising relative to the substrate on which the fish is placed. The pressure surface is configured to slide against the rising area of the fish. Under a force of the pressure surface of the pressure part being lowered onto the rising area of the fish, the fish is displaced and positioned for heading.
| 0
|
FIELD OF THE INVENTION
The invention relates to a compact time-of-flight mass spectrometer which enables very accurate mass determinations.
BACKGROUND OF THE INVENTION
The best choice of mass spectrometer for measuring the mass of large molecules, as undertaken particularly in biochemistry, is a time-of-flight mass spectrometer because it does not suffer from the limited mass range of other mass spectrometers. Time-of-flight mass spectrometers are frequently abbreviated to TOF or TOF-MS.
Two different types of time-of-flight mass spectrometer have been developed. The first type comprises time-of-flight mass spectrometers for measuring ions which are generated in pulses in a tiny volume and accelerated axially into the flight path, for example with ionization by matrix-assisted laser desorption, MALDI for short, a method of ionization suitable for ionizing large molecules.
The second type comprises time-of-flight mass spectrometers for the continuous injection of an ion beam, one section of which is ejected as a pulse in a “pulser” transversely to the direction of injection and forced to fly through a mass spectrometer with reflector as a linearly spread ion beam lying transverse to the direction of flight, as the schematic in FIG. 1 shows. A ribbon-shaped ion beam is therefore generated in which ions of the same type, i.e. with the same mass-to-charge ratio, form a transverse front. This second type of time-of-flight mass spectrometer is known for short as an “Orthogonal Time-of-Flight Mass Spectrometer” (OTOF); it is mainly used in conjunction with out-of-vacuum ionization. The most frequently used type of ionization for this type of mass spectrometer is electrospray ionization (ESI). Electrospray ionization (ESI) is suitable for ionizing large molecules in much the same way as MALDI. It is also possible to use other types of ionization, for example chemical ionization at atmospheric pressure (APCI), photoionization at atmospheric pressure (APPI) or matrix-assisted laser desorption at atmospheric pressure (AP-MALDI). Ions generated in-vacuum can also be used. Before they enter the OTOF, the ions can also be selected and fragmented in appropriate devices so that the fragments can be used to improve the characterization of the substances.
In this second type of time-of-flight mass spectrometer, a large number of spectra, each with relatively low ion counts, are generated by a very high number of pulses per unit of time (up to 20,000 pulses per second) in order to utilize the ions of the continuous ion beam as effectively as possible.
As with all mass spectrometers, with a time-of-flight mass spectrometer one can only determine the ratio of the mass m of the ion to the number z of elementary charges which the ion carries. Any subsequent reference to “specific mass” or quite simply to “mass” on its own always means the ratio m/z. If, by way of exception, “mass” in the following text is to be taken to mean the physical dimension of the mass, it will be specifically called molecular mass The unit of molecular mass m is the “unified atomic mass unit”, abbreviated to “u”, usually simply termed “mass unit” or “atomic mass unit”. In biochemistry and molecular biology, the unit “Dalton” (“Da”) is still frequently used. The unit of specific mass m/z is “atomic mass unit per elementary charge” or “Dalton per elementary charge”, where the elementary charge is the charge on an electron (if negative) or proton (if positive).
FIG. 1 shows the principle of a reflector time-of-flight mass spectrometer with orthogonal ion injection. In the pulser, the ions are accelerated transversely to their direction of injection (x-direction); the direction of acceleration is called the y-direction. The ions leave the pulser through slits in slit diaphragms, which can also be used for angular focusing in a z-direction which is at right angles to the x- and y-directions. After being accelerated, however, the ions have a direction which lies between the y-direction and the x-direction, since they fully retain their original velocity in the x-direction. The angle to the y-direction is α=arctan √(E x /E y ), where E x is the kinetic energy of the ions in the primary beam in the x-direction and E y the energy of the ions after being accelerated in the y-direction The direction in which the ions fly after the pulsed ejection is independent of the mass of the ions.
The ions which have left the pulser now form a broad ribbon, where ions of the same type (the same specific mass m/z) are all to be found in one front, which has the width of the beam in the pulser: Light ions fly faster, heavy ones slower, but all fly in the same direction, with the exception of possible slight differences in direction which can arise as a result of the slightly different kinetic energies E x of the ions as they are injected into the pulser. These ions are therefore injected as monoenergetically as possible. The field-free flight path must be completely surrounded by the accelerating potential in order not to disturb the ions in flight.
As reported by W. C. Wiley and I. H. McLaren (Rev Sci Instrum 26 (1955) 1150), ions with the same specific mass which are at different locations of the beam cross section can be time-of-flight focused with respect to their different start locations by selecting the field in the pulser in such a way when switching on the outpulsing voltage that the ions furthest away are given a slightly higher acceleration energy to enable them to catch up with the leading ions again in a time-of-flight focal point. The time-of-flight focal point can be positioned as desired by means of the outpulse field strength in the pulser. This converts the initial spatial dispersion of the ions into an energy dispersion. The energy dispersion is compensated by the reflector in the known way.
To scan ion beams in time-of-flight spectrometers, instruments currently commercially available incorporate so-called channel plate secondary-electron multipliers by which the ion beams are amplified; these amplified currents are fed into fast transient recorders. The fast transient recorders digitize the amplified ion beams at the rate of one to four gigahertz in analog-to-digital converters with a signal resolution of usually eight bits.
In order to achieve a high resolution, the mass spectrometers (both axial and orthogonal time-of-flight mass spectrometers) are equipped with at least one energy focusing reflector which reflects the outpulsed ion beam toward the ion detector, thereby accurately time focusing ions of the same mass but slightly different initial kinetic energy in the y-direction onto the large-area detector. The ions fly out of the (last) reflector towards a detector which, in the case of orthogonal time-of-flight mass spectrometers, must be of the same width as the ion beam in order to be able to measure all incident ions. This detector also must be aligned parallel to the x-direction, as shown in FIG. 1, in order to also concurrently detect the front of flying ions of the same mass.
The resolution R and the mass accuracy of a time-of-flight mass spectrometer are proportional to the flight distance. It is therefore possible to increase the resolution by selecting a very long flight tube or by introducing several reflectors to produce multiple reflections. For example, with a flight path of one and a half meters one can achieve a mass resolution of around R=m/Δm=10,000; with around six meters, a mass resolution of R=m/Δm=40,000 (where Δm is the line width of the ion signal at half maximum, measured in mass units).
Flight tubes of several meters in length are very inconvenient because they result in unwieldy instruments. Multiple reflections are also problematic, however, because, until now, the angular focusings of the divergent ion beam, which are actually very desirable, have not been satisfactorily solved.
It is, however, also known that time-of-flight mass spectrometers exist which incorporate cylindrical capacitors in the flight path, thus enabling a small instrument to have a long flight path. In this case, a cylindrical capacitor offers angular focusing (for the angle φ, which lies in a plane which intersects the cylinder axis at right angles), angular focusing with respect to energy spreads and time-of-flight focusing with respect to the initial angular spreads for ions of the same specific mass, which can be used for long flight paths.
J. M. B. Bakker (Int. J. Mass Spectrom. Ion Phys. 6(1971)291-295) presents an instrument which achieves energy spread focusing using a combination of straight flight paths with flight paths in cylindrical capacitors. In this paper, both the angular focusing for φ and the angular focusing with respect to energy spreads in cylindrical capacitors seem to be known, and it is shown that for purely energy focusing, one can shorten the rotational angle for the energy focusing using a combination of linear and circular paths.—Combinations of linear and circular flight paths for angular focusings have been known for many decades and details can be found in relevant text books.—A. A. Sysoev et al. (Fresenius J. Anal. Chem. 361 (1998) 261-266) present an instrument which incorporates a cylindrical capacitor of 509° whose energy dispersion appears to be neutralized again by means of a linear continuation of the path to the detector. The 509° are only depicted in a diagram, the precise conditions of the energy focusing are not given.—In an ion-optical paper on time-of-flight mass spectrometers with electric sector fields (cylindrical capacitors), A. A. Sysoev (Eur. J. Mass Spectrom. 6 (2000) 501-513) demonstrates solutions for using shorter circular trajectories in cylindrical capacitors in combination with linear flight paths.
In a cylindrical capacitor, ions which enter monoenergetically in a point undergo angular focusing with respect to the angle of incidence Φ after 127.28°=180°/√2; ions of the same specific mass experience thereby a time-of-flight dispersion, however. This focusing means that ions with different starting angles come together again in the trajectory at one focal point, but ions of the same mass do not arrive there simultaneously because the path lengths for the ions of different angles are different. We will call this type of focusing “angular focusing with time-of-flight dispersion”.
After sweeping this angle twice, i.e. after sweeping an angle of 254.56°=2×127.28°(360°/√2), an angular focusing then occurs again, but this time together with a time-of-flight focusing (if a time-of-flight focusing was present at the beginning of the first angle), since the time-of-flight dispersion of the first half is precisely compensated for. We will call this focusing “angular focusing with time-of-flight focusing”.
In a cylindrical capacitor, ions which enter in a point and are time-of-flight focused but energy dispersive become spatially focused with respect to their energy spread after sweeping an angle of 254.56°=2×127.28 °=360°/√2; ions of the same specific mass experience a time-of-flight dispersion as a result, however. This focusing means that ions with different energies of incidence come together again in the trajectory at one focal point, but ions of the same mass do not arrive there simultaneously because the path lengths for the ions with different energies are different. We will call this type of focusing “energy focusing with time-of-flight dispersion”. After this special angle there thus occurs an “angular focusing with time-of-flight dispersion” and an “energy focusing with time-of-flight dispersion”.
After sweeping this angle twice, i.e. after sweeping an angle of 509.12°=2×254.56°=360°×√2, an energy focusing then occurs again, but unfortunately this time without the time-of-flight focusing which occurs with angular focusing. The time-of-flight dispersions do not compensate each other but double instead. In the case of cylindrical capacitors it is therefore generally not possible to achieve an “energy focusing with time-of-flight focusing”.
The time-of-flight dispersion of the energy focusing after 254.56° is worth mentioning because here, the lower energy, i.e. slower, ions fly ahead and the higher energy ions arrive later. It is thus possible to again compensate the energy dispersion with a linear flight path. This flight path is, however, relatively long so that it is not possible to build a particularly small mass spectrometer simply by combining a cylindrical capacitor and a linear flight path.
SUMMARY OF THE INVENTION
One approach begins with the idea of positioning two cylindrical capacitors, each with 254.56°, opposite each other in such a way that the trajectory through both cylindrical capacitors resembles a “figure 8”. In each case, straight flight paths, whose length is determined by the radius of the cylindrical capacitors, are then created between the circular trajectories in the cylindrical capacitors. However, these straight flight paths are unfortunately too short to compensate the time-of-flight dispersion which arises as a result of the sweep through the cylindrical capacitors. A time-of-flight dispersion remains which increases with each repeated sweep through the “8” and which can only be compensated by a longer, linear flight path. The longer, linear flight path prevents the construction of a very small instrument.
The invention involves virtually increasing the lengths of the straight flight paths between the two cylindrical capacitors for the ions, in order to compensate the time-of-flight dispersion of the cylindrical capacitor with 254.56° by means of this internal flight path. The virtual extension of the linear flight path is caused by a flight path which is at a different potential referred to the mid potential in the cylindrical capacitors. The ions must be decelerated as they emerge from the cylindrical capacitor and accelerated again as they enter the next cylindrical capacitor. The ions therefore fly slower in this flight path and, since the energy spread of the ions remains constant, the faster ions can catch up with the slower ones on a shorter path. With a simple adjustment of the potential of the linear flight path, optimum compensation of the time-of-flight dispersion can be achieved.
Special corrective potentials must be inserted between cylindrical capacitor and straight flight paths in order to achieve a good transition in spite of the deceleration. The corrective potentials are applied to corrective electrodes and consist of one pair of electrodes to compensate for the scattering potential of the cylindrical capacitor and one pair of electrodes which forms an ion lens.
Ions which are parallel and time focused when they enter one of the cylindrical capacitors experience two angular focal points each time they sweep through a cylindrical capacitor and are again parallel each time they emerge. (Other types of operation are also possible and are described below). At the end of each of the linear flight paths (before the ions enter the next cylindrical capacitor) a time-of-flight focusing of ions of the same mass is always achieved.
Therefore, if a pulsed ion source is mounted in such a way that a parallel, time focused entry of the ions into the first cylindrical capacitor is achieved then, at the end of the linear flight path which was swept last, a detector can measure a high resolution mass spectrum. Further possible geometries for the operation are discussed below. In particular, an ion beam can be helically spiraled in each cylindrical capacitor by injecting it at a slightly oblique angle (with a motion component in the direction of the axis of the cylindrical capacitors) so that after multiple sweeps, the ion source and detector do not cause an obstruction.
This invention can be used to construct different configurations of relatively small time-of-flight mass spectrometers; in each case the configuration depends greatly on the type of ion generation and the planned mass resolution. It is particularly worth mentioning, for example, an embodiment for ions of a continuous ion beam in the y-direction parallel to the axial direction of the cylindrical capacitor, from which the ions of individual sections of the ion beam are pulser injected in the form of an ion ribbon in the y-direction tangentially into the cylindrical capacitor. The ions thus accelerated fly obliquely out of the pulser in the form of an ion ribbon, and the initial velocity of the ions in the x-direction is maintained. As already described above, the angle to the y-direction is α=arctan √(E x E y ), where E x is the kinetic energy of the ions in the primary beam in the x-direction and E y the energy of the ions after being accelerated in the y-direction. When the cylindrical capacitor is correctly dimensioned, this angle α produces the helical spiraling of the ion trajectory within each cylindrical capacitor.
It is not necessary that the pulser and detector are mounted between the cylindrical capacitors. By moving the two cylindrical capacitors axially with respect to each other, the pulser or detector can also be further away from the entrance into the cylindrical capacitor than the length of the straight path between the two cylindrical capacitors; the ion beam is led past the end of the cylindrical capacitors in each case. The overcompensation of the time-of-flight dispersion by the longer path can thus be compensated by adjusting the potential of the straight flight paths because the time-of-flight compensation is achieved by the sum and does not depend on the time-of-flight compensation of the individual paths.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and further advantages of the invention may be better understood by referring to the following description in conjunction with the accompanying drawings in which:
FIG. 1 shows a schematic diagram of a conventional time-of-flight mass spectrometer with orthogonal ion injection.
FIG. 2, shows a set of cylindrical capacitors positioned opposite each other so as to create an ion trajectory resembling a “figure 8.”
FIG. 3 shows a refinement of the arrangement shown in FIG. 2, achieved by adding a pair of corrective electrodes ( 34 ) and a pair of lens electrodes ( 35 ).
FIG. 4 illustrates a mode in which the lens electrodes ( 35 ) generate a focal point ( 29 ) at the center of the system.
FIG. 5 is the schematic representation of the ion beam of a time-of-flight mass spectrometer for orthogonal ion injection according to this invention.
DETAILED DESCRIPTION
FIG. 1 shows a schematic diagram of a conventional time-of-flight mass spectrometer with orthogonal ion injection. Through an opening ( 1 ) in a vacuum chamber ( 2 ), a beam ( 3 ) of ions with different initial energies and initial directions enters an ion guide system ( 4 ) located in a gastight container. Damping gas also enters the ion guide system simultaneously. The ions entering the gas are decelerated by collisions. In the ion guide system there exists a pseudo-potential for the ions which is lowest on the axis ( 5 ), and so the ions collect on the axis ( 5 ). The ions spread out along the axis ( 5 ) up to the end of the ion guide system ( 4 ). The gas from the ion guide system is evacuated by the vacuum pump ( 6 ) on the vacuum chamber ( 2 ).
At the end of the ion guide system ( 4 ) there is a puller lens system ( 7 ). An apertured diaphragm of this puller lens system is integrated into the wall ( 8 ) between vacuum chamber ( 2 ) for the ion guide system ( 4 ) and vacuum chamber ( 9 ) for the time-of-flight mass spectrometer. The latter is evacuated by means of a vacuum pump ( 10 ). In this schematic the puller lens system ( 7 ) consists of five apertured diaphragms; it extracts the ions from the ion guide system ( 4 ) and forms a thin ion beam with small phase volume which is focused into the pulser ( 12 ). The ion beam is injected into the pulser in the x-direction. When the pulser is full with ions in transit with the preferred mass for analysis, then a short voltage pulse accelerates a broad packet of ions transversely to the previous direction of flight in the y-direction and forms a broad ion beam which is reflected in a reflector ( 13 ) and measured with high time resolution by an ion detector ( 14 ). In the ion detector ( 14 ) the ion signal, which is amplified in a secondary-electron multiplier in the form of a double multichannel plate, is transferred capacitively to a 50Ω cone. This previously amplified signal is transmitted via a 50Ω cable to an amplifier. The 50Ω cone serves to terminate the cable at the input side so that no signal reflections can occur here.
In this schematic, reflector ( 13 ) and detector ( 14 ) are aligned exactly parallel to the x-axis of the ions injected into the pulser. The distance between detector ( 14 ) and pulser ( 12 ) determines the maximum degree of utilization for ions from the thin ion beam.
In contrast, we now discuss a first embodiment according to this invention. This embodiment operates as a time-of-flight mass spectrometer with orthogonal ion injection of a continuous ion beam, for example for an ion beam from an ionization by electrospray ionization (ESI). Anyone skilled in the art can also transfer the principle to other ion sources with other types of ionization.
The principle of ion beam guidance is shown in FIG. 5, the details of how to focus the ion beam with respect to the angle of injection can be seen in FIG. 4 . The plates of the cylindrical capacitors ( 21 ), ( 22 ), ( 23 ) and ( 24 ) as well as the housing ( 25 ) extend over the complete depth of the trajectory in the x-direction, the direction of the primary ion beam ( 40 ), from the pulser ( 41 ) to the detector ( 43 ) in FIG. 5 .
As is the case with a conventional time-of-flight mass spectrometer with orthogonal ion injection, as shown in FIG. 1, the primary ion beam is initially damped in an RF ion guide system filled with collision gas at a pressure of around 10 −2 Pascal in such a way that the ions generated are practically monoenergetic. An accelerating lens then forms them into a thin ion beam ( 40 ) which is merged into the pulser ( 41 ) of the mass spectrometer. The ions here have a kinetic energy E x which can be adjusted to between around 20 and 40 electron volts. We call the direction of this primary ion beam the x-direction. This pulser is made up of a series of slit diaphragms which enable the ion beam to be accelerated as a pulse in the y-direction, which is at right angles to the primary x-direction. The slit diaphragms are more effective than the pulser grid ( 12 ) in FIG. 1; they allow the formation of a ribbon-shaped beam approximately two centimeters wide with a very slight divergence and which appears to originate from a very small, linear, extended originating location. The kinetic energy E y of the ions transverse to the primary direction is approximately eight kilovolts.
After being accelerated in the y-direction, the ion beam ribbon has a direction which lies between the y-direction and the x-direction, since the ions fully retain their original velocity in the x-direction. The angle to the y-direction is α=arctan √(E x E y ), where E x is the kinetic energy of the ions in the primary beam in the x-direction and E y the energy of the ions after being accelerated in the y-direction. The direction in which the ions fly after the pulsed ejection is independent of the mass of the ions. The angle α can be set by selecting the primary energy E x . The angle α causes the ribbon-shaped ion beam to be helically spiraled each time it flies through one of the cylindrical capacitors; each of the linear sections of the ion beam also has a forward thrust in the x-direction, i.e. in the direction of the axis of the cylindrical capacitors.
If this pulser is arranged in the mass spectrometer is such a way that it positions the originating location at the crossover point ( 29 ) of FIG. 4, then the ribbon-shaped ion beam can be injected into the cylindrical capacitor ( 21 , 22 ) as a slightly divergent ion beam ( 36 ) as shown in FIG. 4 . Since the beam must be parallel when it enters here, the lens ( 35 ) is adjusted so that it transforms the slightly divergent beam into a parallel beam. The electrode pair ( 34 ) is supplied with a slightly asymmetric potential whose sole purpose is to compensate the scatter field of the cylindrical capacitor ( 21 , 22 ) outside the boundary. This ion-optical trick is familiar to anyone skilled in the art. During the figure-of-8 path through the cylindrical capacitors the forward thrust in the x-direction is maintained, resulting in the trajectory shown in FIG. 5 .
In this case, the pulser can be operated to extract ions from different initial positions transversely to the primary ion beam so that these ions enter the first cylindrical capacitor at exactly the same time, although with a slight energy dispersion; this transforms the spatial distribution into an energy distribution. The resulting energy distribution again causes a time-of-flight dispersion for each sweep of one of the cylindrical capacitors which has to be compensated by a corresponding straight section of trajectory.
The ion beam now follows the path shown in FIG. 4 . Each time it sweeps through one of the two cylindrical capacitors it undergoes two angular focusings. In each cylindrical capacitor, a total of one angular focusing with time-of-flight focusing takes place and this has the effect of making the beam, which is parallel when it enters, still parallel as it emerges, and ensures that no time-of-flight dispersion of ions with different entry angles occurs, provided that these ions have the same mass and the same initial energy. Each time it sweeps through one of the two cylindrical capacitors the ion beam also undergoes a spatial focusing with respect to the spread of the initial energies, i.e. an energy focusing with time-of-flight dispersion. This means that ions with different initial energies which are parallel on entry are also perfectly parallel when they emerge again, although at slightly different times.
According to the invention, this time-of-flight dispersion is now compensated again on the linear flight paths by flying through the linear sections with a different kinetic energy to the kinetic energy for the circular sections in the cylindrical capacitors. This corresponds to a virtual extension of this section.
In the pulser, the ions receive a kinetic energy of eight kilovolts, for example. On entering the cylindrical capacitor, an acceleration of approximately 2.5 kilovolts is imparted to them in the region of the lens and the corrective electrodes. This additional acceleration can be finely adjusted via the potentials of the housing ( 25 ) and the potential of the cylindrical capacitor plates ( 21 ), ( 22 ), ( 23 ) and ( 24 ). On emerging from the cylindrical capacitor the ions are accordingly decelerated once again to eight kilovolts. Acceleration and deceleration occur in this way each time the ions enter and emerge.
In addition, the lens ( 35 ) causes a transition from parallel beam to slightly divergent beam and vice versa each time the ions enter and emerge, as can be seen in FIG. 4 . It is preferable if the lens takes the form of a long slit lens (cylinder lens) which extends over the complete depth of the cylindrical capacitors. The corrective electrodes also take the form of long electrodes. For each section it is also possible to use individual lens diaphragms and corrective diaphragms, however.
As is the case with the pulser, the detector ( 43 ) can also be mounted in the center of the system although this arrangement is neither imperative nor justified on the grounds that it compensates the time-of-flight dispersion. If the arrangement is operated so that a straight section exactly compensates the time-of-flight dispersion of the previous section of flight in the cylindrical capacitor in each case, then at this central point there is no time-of-flight focusing for the detector, since only half a path has been swept since last emerging from a cylindrical capacitor. The time-of-flight focusing can easily be set up, however, by finely adjusting the potential between the housing ( 25 ) and the cylindrical capacitors, since it is not necessary to assign the compensations on the straight sections to the respective time-of-flight trajectories passed through in one of the cylindrical capacitors. Only the sum of the compensations must be correct.
Pulser and detector can also lie outside the housing ( 25 ) if the beam is led past the end of one of the cylindrical capacitors in each case. Hence the detector can also be mounted at any position along the straight flight path outside the cylindrical capacitor; the time-of-flight focusing can be set via the potential difference between the flight potential in the cylindrical capacitor and in the housing.
An instrument with a trajectory as shown in FIG. 5 can easily be constructed as a benchtop instrument. When the radius of the ion trajectory in both cylindrical capacitors is nine centimeters, the instrument can be accommodated in a relatively small vacuum housing measuring 50 centimeters wide, 50 centimeters deep and 25 centimeters high and for a total flight path length of around six meters, it should provide a mass resolution of more than R=40,000. Previous experience has shown that the mass can be determined to within {fraction (1/10)} to {fraction (1/20)} of the signal width. The mass determination may be achieved to within an accuracy of one to two millionths of the mass (1-2 ppm). This relatively simple benchtop instrument is therefore highly accurate given its relatively modest size.
There are also other possibilities for the trajectory through the system apart from those shown in FIGS. 3 and 4. For example, the angular focal points can also lie at the entrance, in the middle or at the exit of the cylindrical capacitors. This requires additional lenses in the housing to focus the focal points on the exit side onto the entrances again.
The use of mass spectrometers such as this is not limited to ion sources which supply a continuous ion beam. Ion sources which use matrix-assisted laser desorption for the ionization can also be used, although they have a somewhat different construction.
When matrix-assisted laser desorption is used for the ionization, analyte molecules on a sample support plate are embedded into small crystals of a matrix substance. Bombarding the crystal conglomerate with a pulse of laser light causes some of the matrix material to vaporize and form a small plasma cloud, blowing analyte molecules into the plasma cloud and ionizing them. This ionization can take place outside the vacuum system although here, ionization in the vacuum system is considered. The plasma cloud expands very rapidly in the vacuum, within tens of nanoseconds, the friction hereby imparting different accelerations to the ions. After a short delay time, the faster ions are further away from the sample support plate; if an accelerating field with a potential gradient is now switched on, slower ions—nearer to the sample support plate—receive a slightly higher additional energy than the fast ones. The ions which were originally slower can now catch up with the ions which were originally faster in a time focus. The potential gradient and the delay time can thus be used to achieve an energy focusing with time focusing whose focal point can be set at a distance of between 5 and 30 centimeters away from the sample support plate. This focusing procedure is called SVCF (space velocity correlation focusing), DE (delayed extraction) or PIE (pulsed ion extraction).
On the other hand, the ions can be generated in the center ( 29 ) of the ion beam trajectory, although this generates a beam which is string-shaped rather than ribbon-shaped. Ions can also be generated at other locations; in these cases the ions are injected into the system in the direction of the primary ion beam ( 40 ) and are guided by an ion reflector in the first cylindrical capacitor instead of by a pulser ( 41 ).
Here, the accelerating optical system of the MALDI ion source can also contain a lens for an angular focusing of the ion beam, which is slightly divergent as a result of the explosive expansion of the plasma cloud; by using two crossed cylinder lenses it is even possible to make the focal lengths in two divergent planes at right angles to each other, different. As an example, it is possible in this way to focus on the entrance point of the cylindrical capacitor in the plane transverse to the axis of the cylindrical capacitor, whereas in the other direction one tries to generate a beam which is as parallel as possible, and which forms as narrow an ion beam as possible at the emergence point.
In principle, the ion beam thus generated then follows the trajectory ( 42 ) in FIG. 5, although the ion beam is string-shaped rather than ribbon-shaped.
For an accelerating voltage of 25 kilovolts, MALDI ions with a specific mass of 5,000 dalton per elementary charge have a flight time of just under 200 microseconds. A laser pulse rate of 50,000 pulses per second could therefore be applied here before overlapping of the spectra occurs. In practice, however, a maximum of 200 pulses per second is used, and so no deviation in the mode of operation is to be expected as a result of the long flight path.
|
The invention relates to a compact time-of-flight mass spectrometer which enables very accurate mass determinations. The invention consists of a method of producing a high resolution by means of a long flight path, where the ion beam repeatedly sweeps a figure of eight in two opposed cylindrical capacitors, each of 254.56°, and the linear ion beam paths between the cylindrical capacitors are extended virtually by a change in potential so as to cause a time focusing with respect to an initial energy spread.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Continuation-In-Part (C.I.P.) of application Ser. No. 11/156,638 filed on Jun. 21, 2005, now abandoned, and benefit of U.S. Provisional Application for Patent Ser. No. 60/581,456, filed on Jun. 22, 2004, is hereby claimed.
FIELD OF THE INVENTION
[0002] The present invention relates to feeding apparatuses for animals and methods, and is more particularly concerned with such an apparatus for automatically, or manually, feeding pellets and/or hay to horses.
BACKGROUND OF THE INVENTION
[0003] It is well known in the art to have a feeder for animals such as horses and the like. U.S. Pat. No. 3,845,744 issued to H. Carr on Nov. 5, 1974 provides for a feeder with a relatively complex mechanism for opening the doors one by one and ensuring that the system closes all doors when the lid is opened. Moreover, the constriction of the hopper could potentially block or choke the delivery of feed to the animal(s) with perturbing circumstances. Finally, the lid being positioned above the feeder significantly hampers the delivery of heavy bags of pellets, for example, which must be lifted above the feeder. U.S. Pat. No. 5,899,169 issued to B. Jenson et al. on May 4, 1999 shows hayracks which, if strong enough not to be damaged by the animal, provide for a more complicated and probably heavier feeder to build. In addition, a hazard will always exists on this design with an automatic opening of one of the doors while an animal is eating, potentially hurting the nose or nostrils of the animal.
[0004] U.S. Pat. No. 5,970,912 issued to K. Supple et al. on Oct. 26, 1999 discloses a feeder that generally releases all the food contained therein at a certain time. It is therefore necessary to reload the feeder regularly and this, only for one type of food material. Furthermore, in this invention also there is a hazard that the tray or the armature structure could hurt the animal when the controller releases the tray open. U.S. Pat. No. 6,715,443 issued to A. Bernard on Apr. 6, 2004 provides for some of the same disadvantages as earlier described. One can consider for example the difficulty to fill the device without having to release it from the support structure and the potential to harm the animal with one of the bottom walls or with the protruding pin component when the bottom wall is released open.
[0005] Accordingly, there is a need for an improved automated feeder apparatus for animals.
SUMMARY OF THE INVENTION
[0006] It is therefore a general object of the present invention to provide an improved automated feeder apparatus for animals.
[0007] An advantage of the present invention is that the feeder apparatus provides for a feeding mechanism designed to avoid hurting the muzzle of the animal, more specifically the nose, nostrils and mouth.
[0008] Another advantage of the present invention is that the feeder apparatus provides for a protected feeding mechanism in order to avoid being damaged by the muzzle of the animal.
[0009] A further advantage of the present invention is that the feeding apparatus has at least two separate feed lines providing for two types of food material that can be delivered simultaneously or consecutively and that provides for either an automated or manual activation.
[0010] Still another advantage of the present invention is that the feeding apparatus provides for an easily accessible horizontal access to the feeding area for filling and refilling the different types of food material for the animals.
[0011] Still a further advantage of the present invention is that the feeding apparatus holds separate feed section and a feed deflector.
[0012] Another advantage of the present invention is that the feeding apparatus provides for a delivery of the food material without blocking.
[0013] Still a further advantage of the present invention is that the feeding apparatus provides for at least one of the feeds that can be partially activated to deliver only a limited quantity of food material at a given time.
[0014] Still another advantage of the present invention is that the feeding apparatus provides for a simple, economically sound and easy to manufacture mechanical arrangement.
[0015] Another advantage of the present invention is that the feeding apparatus may be situated within an animal stable or box or externally thereof, dependent upon the nature of the stable facility.
[0016] According to an aspect of the present invention, there is provided a feeding apparatus for animals consisting of a box structure comprising a hinged upper front door, a secured lower front panel, a top panel, a pair of side panels, a back panel, the upper front door and lower front panel, side and back panels bordering a series of compartments for feed materials, each of the compartments being provided with a lower hinged discharge door, a door locking and opening system adapted to activate the respective lower hinged discharge door to open to enable feed materials to fall by gravity towards a feed area and an independent door closing system adapted to close the lower hinged discharge doors, the lower front panel, the side panels and the back panel being configured and sized to extend downwardly enough to enclose the lower hinged discharge doors when in an open position, and an angularly orientable deflector plate being disposed beneath the discharge doors and being adjustably attached to deflector plate supports through the agency of pin and slot arrangements, the deflector plate in use deflecting the feed materials falling from the discharge doors towards the feed area, and some of the deflector plate supports being mountable in such manner as in use to accommodate movement by an external force.
[0017] The movable supports may conveniently be pivotally mounted.
[0018] The pin and slot arrangements may be provided respectively on the deflector plate and on the deflector plate supports.
[0019] Each pin and slot arrangement comprises a pin slidably mounted in both a corresponding support slot of the deflector plate support and a corresponding plate slot of the deflector plate, the pin being slidably movable simultaneously in both the corresponding support slot and the plate slot.
[0020] The deflector plate is conveniently provided beneath the discharge doors to facilitate flow of the feed materials to the feed area which may simply be the ground or may be a feed trough for the animals. The angular inclination of the deflector plate is adjustable to afford a degree of modulation to cater for differing feed consistencies or feed rates.
[0021] The deflector plate may be mounted on plate supports connected to the apparatus and mounting feet may be advantageously mounted at a lower end of the plate supports in such manner as to allow of the movement hereinbefore mentioned.
[0022] A separate compartment or compartments may be provided for other feed materials, for example granular feeds, which may benefit from different conveying regimes. In one example of the invention the conveying regime may comprise a screw feeder for transporting the feed from the compartment to a receptor, for example a manger or feed pan, suitably disposed for ease of access by the animal.
[0023] Each lower hinged discharge door may be unitary or may be formed in two separate parts each essentially comprising a half-door. In the case where half-doors are adopted integrated operation thereof may be provided for by means of a simple lever and over-centre arrangement of the door locking and opening system and the door closing system.
[0024] The control of the feeding apparatus may be such as to allow incremental feeding by for example stepwise opening of the lower discharge doors.
[0025] A portion of the feeding apparatus of the invention may be electrified to protect it from inadvertent damage by the animal. In the alternative the whole of the apparatus is electrified.
[0026] Other objects and advantages of the present invention will become apparent from a careful reading of the detailed description provided herein, with appropriate reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Further aspects and advantages of the present invention will become better understood with reference to the description in association with the following Figures, wherein:
[0028] FIG. 1 is a simplified front perspective view of a feeding apparatus in accordance with an embodiment of the present invention, with the upper front door in the open position showing access to the feed compartments on the refill side;
[0029] FIG. 2 is a simplified rear perspective view of the embodiment of FIG. 1 , showing the discharge side, namely the animal side, of the apparatus;
[0030] FIG. 3 is a side view of the apparatus shown in situ on the outside of a horse loose box or stable;
[0031] FIGS. 4 to 6 are section views taken along line 4 - 4 of FIG. 1 , showing the stages of closure of the lower hinged discharge doors;
[0032] FIGS. 7 to 12 illustrate an alternative form of lower hinged discharge door arrangement;
[0033] FIGS. 13 to 15 show schematically an alternative operating arrangement for the lower hinged discharge doors;
[0034] FIG. 16 shows a discharge system for granular feed materials;
[0035] FIG. 17 is a perspective front view of a feeding apparatus according to the invention showing a further embodiment of a detail thereof; and
[0036] FIG. 18 is a scrap side view of the details shown in FIG. 17 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] With reference to the annexed drawings the preferred embodiments of the present invention will be herein described for indicative purpose and by no means as of limitation with like numerals of reference being employed for like parts in differing embodiments of the invention or its details.
[0038] Referring first to FIGS. 1 to 3 there is schematically shown a feeding apparatus 1 in accordance with the present invention. The apparatus essentially consists of a box structure 2 having an upper feed or input region 4 with a top panel 3 and a relatively lower discharge region 6 defined between front 14 and end panels 5 , 7 .
[0039] The upper feed region 4 comprises a series of compartments 8 , 70 (two hay compartments 8 and two smaller pellet end compartments 70 shown in FIG. 1 for example) separated by partition walls 9 , 9 ′ accessed through a common opening 10 closable by a hinged upper front door 12 ( FIG. 1 ) superposing a lower fixed front panel 14 . The rear or animal side of the upper feed region is closed by a back panel 15 . Each compartment 8 is provided with a lower hinged discharge door 16 within the lower discharge region 6 , the doors 16 being actuable for closure by a handle 20 of a door closing system suitably mounted externally of the upper and lower regions as shown. The handle 20 is carried by and is rigid with a shaft 22 provided with a plurality of tines 24 which co-operate with the doors as more clearly seen in FIGS. 4 to 6 . An electro-magnetic lock 30 of a door locking and opening system may be provided for each door 16 to maintain it in a closed position ( FIG. 6 ) and to release it into an open position ( FIG. 4 ) as and when required, repositioning of the door into the closed position being effected by suitable movement of the handle 20 and thus the tines 24 ( FIG. 5 ). A programmable timer 26 (shown in dotted lines in FIG. 1 , above the end compartments 70 ) with corresponding control panel 27 may conveniently be provided for actuation of the locks 30 which may operate simultaneously or sequentially in timed fashion. The handle 20 and shaft 22 are typically maintained in a parked position shown in FIGS. 1 , 5 and 6 by a biasing spring or the like (not shown).
[0040] The lower discharge region 6 is defined between the end panels 5 , 7 which are fixed and between lower front 14 and back 15 panels which are also fixed, the lower hinged discharge doors 16 being wholly contained within the confines of the end panels 5 , 7 and the front 14 and back 15 panels.
[0041] A discharge zone 40 is provided subjacent the discharge region 6 and is in one embodiment as shown in FIGS. 1 , 2 and 3 constrained between deflector plate supports 42 situated at the corners of the box structure 2 and their optional side walls 42 a . The discharge zone 40 accommodates a feed deflector plate 44 for conveying the feed in use from beneath the discharge doors 16 to a feed area 50 within a horse loose box 60 , one wall 62 of which is shown in dotted outline in FIG. 3 . In this instance, the feeding apparatus 1 is situated exteriorly of the loose box 60 and is affixed to the wall 62 . The advantage of this arrangement is that recharging of the apparatus with fresh supplies of feed may be effected without having to gain access to the loose box. The feed deflector plate 44 is angularly adjustable and to this end is provided in association with the plate supports 42 with pin and slot arrangements 45 , with each arrangement 45 having a pin slidably engaged and simultaneously slidably movable in both in a corresponding plate slot and a corresponding plate support slot of preferably equal length. Thus, the plate may be disposed at a suitable, and reversible, inclination to assist flow of the feed material, for example hay, in register with an access opening 64 of the wall 62 . Typically, the plate supports 42 remain spaced from the floor (not shown) to ensure that there is enough room for the animal's legs to move around without hitting the apparatus. Optionally, mounting feet 43 could be releasably affixed to the lower end of plate supports 42 to help supporting the weight of the apparatus 1 via the floor.
[0042] In an alternative embodiment the feeding apparatus is located with the box 60 with access being provided externally thereof through the upper door 12 .
[0043] In further alternative embodiments the plate supports 42 may be omitted, a deflector plate if required being independently situated in an appropriate position.
[0044] The upper feed region 4 is additionally provided with end compartments 70 (separated by partition wall 9 ′) for containing granular feed and is provided with a corresponding hopper 47 and outlet 48 instead of the deflector plate 44 to redirect the flow of pellet or the like there from toward a separate container, trough or the like (not shown). Alternatively, the end compartments 70 are provided with a screw conveyor 71 ( FIG. 16 in particular) with a discharge outlet 72 leading from the screw section 73 . An electric motor 75 is provided for powering the rotation of the screw section 73 and may be actuated by the controller 26 on a timed and duration basis to give the appropriate feed amounts delivered periodically as required.
[0045] Referring now specifically to FIGS. 7 to 12 , there is shown in illustrative manner an alternative lower hinged discharge door arrangement combining the door locking and opening system with the door closing system. In particular there is depicted a half-door assembly 80 in which each discharge door comprises two half doors 82 hingedly mounted on the confining front and rear walls or panels and interconnected by a mechanical linkage 84 including two operating limbs 83 pivoted together by a pin 85 movable in a crosshead 87 . Each half door 82 has a lynch pin 89 connected to a respective limb 83 , the pins 89 being movable within arcuate slots 90 . A crank lever assembly 100 is provided as an actuating mechanism for moving the half doors in unison between their open and closed positions. Each assembly 100 has a pivoted main crank 102 pivoted to a throw 104 connected to the pin 85 . In operation from the closed position of the half doors 82 , clockwise movement of the crank 102 pulls the limbs 83 upwardly as viewed in the drawing via the throw 104 and the movement of the doors is described visually in FIGS. 7 through 9 in which last figure the doors assume an open position. FIGS. 10 through 12 illustrate the reverse movement from an open position to a closed position. Movement of the half doors 12 may be effected manually or automatically as desired.
[0046] Referring now to FIGS. 13 to 15 , there is depicted an alternative form of operating shaft 220 of a door closing system for the doors 16 in which the shaft is provided with one or a series of flats 222 corresponding to the number of doors. The flats are engageable with in-turned cooperating flanges 226 provided on the door hinges 228 whereby abutment of the flats 222 with the flanges 226 and rotation of the shaft 220 effects movement of the doors. FIG. 13 shows the door 16 closed and locked by an electromagnet in that position, with the shaft 220 in the parked position. FIG. 14 shows the door in the open position with the flat abutting the flange 226 . Rotation of the shaft from the position shown in FIG. 14 takes the door into the closed horizontal position shown in FIG. 15 ; after which the shaft 22 will typically return in the parked position as shown in FIG. 13 .
[0047] In operation of the apparatus of the present invention, feed is charged through the common opening 10 and door 12 into the compartments 8 and is held there by the doors 16 . When desired the doors are opened either automatically or manually to release the feed within the apparatus to descend under the influence of gravity onto the deflector plate 44 . The doors in the fully open position are wholly confined within the discharge zone and are not contactable by the animal feeding from the materials discharged.
[0048] Referring now to FIGS. 17 and 18 there is illustrated the wall 62 of a loose box 60 with a feed apparatus 1 ′ of generally similar configuration as that shown and described in the earlier figures. The apparatus differs in respect of the deflector plate 44 ′ and its support legs 42 ′, 42 ″. In these respects the deflector plate 44 ′ has upturned sides 43 ′ which are adjustable attachable to the legs 42 ′ through the agency of pin and slot arrangements 45 ′, 45 ″. In this particular embodiment a lockable pin and slot arrangement 45 ′ is provided separately in each of the sides 43 ′ and a lockable pin and slot arrangement 45 ″ is provided separately on each of the support legs 42 ′, the pins on the sides 43 ′ engaging slots on the legs 42 ′ and the pins on the legs respectively engaging the slots on the sides 43 ′. The support legs 42 ′ are secured to the wall 62 while the support legs 42 ″ are secured to the apparatus 1 ′ by means of a pivot pin mount 41 ′ which is adapted to allow some movement of the plate 44 ′ relative thereto upon application of an external force of a predetermined level, especially using spacers at the mounting of support legs 42 ″ at pivot pin mounts 41 ′. In this manner, should an animal, for example a horse, nudge or otherwise move the plate 44 ′, the resulting movement of the latter will be accommodated by virtue of the pivotal mount 41 ′. It will be understood that the lockable pin and slot arrangements are normally locked in position, but not sufficiently tightly to prevent sliding movement of the pins relative to the slots.
[0049] As will be seen from FIGS. 17 and 18 should a horse nudge the deflector plate 44 ′ in the direction of arrow A, the plate 44 ′ will move upwardly and in so doing will cause the leg 42 ″ to pivot about its mount 41 ′ along the path designated B and the plate 44 ′ will also move in the direction of arrow C. This movement is compensatory to avoid damage that would otherwise be sustained in the absence of articulation of this kind. The angular setting of the plate 44 ′ can readily be re-established by appropriate adjustment.
[0050] Accordingly, the plate is yieldable in response to outside forces to the extent of the slot dimension. It will readily be understood by the skilled addressee that a variety of pin and slot arrangements may be employed to lend versatility to the positioning of the deflector plate 44 ′. For example the arrangements illustrated in FIGS. 1 , 2 and 3 could be adopted in combination with the embodiment of FIGS. 17 and 18 to allow repositioning of the plate to any desired angular disposition, as exemplified by slots 46 ′ and 46 ″ shown in dotted lines in FIG. 18 .
[0051] The present invention thus provides a simple and yet effective feeding apparatus for an animal, for example a horse, and enables feeding to be conducted automatically or manually and without the need for a physical presence of a groom in the loose box or the stable. Recharging of the feed materials is easily effected externally of the area within which the animal is kept.
[0052] An important feature of the invention resides in the confinement of the lower hinged discharge doors which are not contactable by the animal during use, thus avoiding damage to either the animal or the apparatus.
[0053] In a further refinement of the invention, the apparatus may be provided with protection against accidental and inadvertent damage caused by the animal. In this connection, the apparatus or parts thereof may be electrified as a warning measure to keep the animal away there from. The animal would thus receive a mild shock in the event that it contacts a sensitive part of the mechanism, for example the control panel.
[0054] Although the present invention of a feeding apparatus has been described with a certain degree of particularity, it is to be understood that the disclosure has been made by way of example only and that the present invention is not limited to the features of the embodiments described and illustrated herein, but includes all variations and modifications within the scope and spirit of the invention as hereinafter claimed.
|
An automated feeding apparatus for animals includes a compartmented feed storage container provided with an upper hinged access door for charging the feed into the compartments, which are provided with automatically or manually operable discharge doors. The container is so dimensioned that the discharge doors in their closed and open positions are shielded from an animal feeding from the apparatus. A deflector plate is disposed beneath the discharge doors and is so mounted as to allow and accommodate unintended movement thereof, for example movement occasioned by an animal.
| 0
|
STATEMENT OF THE INVENTION
An improved non-jamming self-adjust pawl and ratchet mechanism is disclosed for use in an automotive parking brake system or the like, including cam-out and cam-in means that are spaced to define an overlap dwell distance for insuring positive suitable engagement between the adjuster pawl and the adjuster ratchet as a foot or hand brake operating lever is pivoted toward a brake fully-engaged position.
BRIEF DESCRIPTION OF THE PRIOR ART
It is known in the prior art to provide a parking brake system including self-adjust means for automatically disengaging the brake cable guide track from the operating lever when the lever is in the brake released position, thereby to remove slack from the cable. Examples of such self-adjust systems are shown in the patents to Porter et al U.S. Pat. No. 4,841,798, Porter U.S. Pat. No. 4,872,368 and Wortmann et al U.S. Pat. No. 5,235,867, each assigned to the same assignee as the instant invention. In order to disengage the cable guide track from the operating lever, it is customary to provide a cam-out pin or abutment on the housing for disengaging an adjuster pawl from an adjuster ratchet when the operating lever is in the brake-off position. When the operating lever is again pivoted in the brake-engaging direction, the spring-biased adjuster pawl is pivoted toward the adjuster ratchet, thereby presenting the possibilities of full tooth engagement, partial tooth engagement (either on the front or rear edges of the associated ratchet tooth), or undesirable top-to-top contact between the teeth, which might lend to a jamming or locking-up of the parking brake mechanism.
The present invention was developed to provide an improved parking brake mechanism for positively eliminating the top-to-top or partial-engagement conditions and for achieving full engagement between the pawl and ratchet teeth.
SUMMARY OF THE INVENTION
Accordingly, a primary object of the present invention is to provide an improved parking brake mechanism of the self-adjust cable-slack-removing type, wherein cam-out means serve to disengage the adjuster pawl from the adjuster ratchet when the operating lever is in the brake fully-released position, and cam-in means are operable to displace the adjuster pawl toward full engagement with the ratchet as the operating lever is pivoted toward the brake fully-applied position, the spacing distance between the cam-out and cam-in means being such as to provide a dwell overlap space between at least the top-off point of lever travel and the initial cam-in point, and preferably between the maximum bounce-back point of lever travel and the initial cam-in point.
In a first embodiment, the parking brake mechanism includes a foot-operated lever that is maintained in the brake-engaged position by clutch spring and gear drum means, the self-adjust cable tension removing means including a pair of cam-out and cam-in pins mounted in spaced relation on the housing, the spacing distance between the pins being such that a dwell overlap space is defined before the adjust pawl engages the cam-in pin, whereby the progressively increasing cable tension reacts together with the adjuster pawl spring relative to the opposing force vectors to assure that the adjuster pawl tooth is in a self-engaging position on the associated ratchet tooth.
In a second embodiment, the foot-lever operating means is maintained in the brake-engaged position by main pawl and main ratchet means. Again, a pair of critically spaced cam-out and cam-in pins are used to effect positive operation of the adjuster pawl relative to the adjuster ratchet.
In a third embodiment, the operating lever is a hand lever that carries the adjuster pawl, a single cam pin being mounted on the housing for reaction between opposed spaced cam-out and cam-in surfaces on the adjuster pawl, the cam-in and cam-out surfaces being so spaced relative to the pin as to provide a dwell overlap distance between the top-off point of travel and the initial cam-in point.
The design of the present invention affords positive re-engagement between the adjuster pawl and ratchet in three ways, namely, by providing additional force via pedal force to break the tip-on-tip equilibrium; by providing a sufficient tooth engagement of the self-adjuster ratchet tooth and the self-adjust pawl that will sustain full system load and the cam-in pin is located in a position to provide proper adjustment function. Sixteen levers were tested in life cycle evaluation. The longest duration test was 125,000 cycles, the minimum duration being 32,106 cycles. Successful cam-in operation of the adjuster pawl was achieved on each occasion. The present invention offers the advantages that tooling modifications can be accomplished with minimum impact on production tooling and assembly processes. Component changes maintain the basic design strength and function of other components in the assembly. Minimal change to normal plant or procedures is required. The auto adjust function is maintained over the life expectancy of the component.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become Other apparent from a study of the following specification, when viewed in the light of the accompanying drawings, in which:
FIGS. 1-4 are diagrammatic views illustrating the adjuster pawl and ratchet means in the back-side tip-on-tip, top-on-top, front-side tip-on-tip, and fully engaged conditions, respectively;
FIGS. 5 and 6 are right side elevation and left hand end views, respectively, of a foot lever parking brake arrangement according to the present invention;
FIGS. 7 and 8 are sectional views taken along lines 7--7 and 8--8, respectively, of FIG. 5;
FIG. 9 is a diagrammatic view of the force vectors acting on the components of FIG. 5;
FIG. 10 is a diagrammatic illustration of the operation of the adjuster pawl of FIGS. 5 and 9 relative to the adjuster ratchet during travel of the lever of the parking Brake apparatus of FIG. 5;
FIGS. 11 and 12 are right side elevational and left hand end views, respectively, of a second foot lever operated embodiment of the invention;
FIGS. 13 and 14 are sectional views taken along lines 13--13 and 14--14 of FIG. 11, respectively;
FIG. 15 shows an adjuster pawl of the second embodiment in FIGS. 11 and 12;
FIGS. 16-18 are right side elevational, right end and top plan views, respectively, of a hand-lever parking brake embodiment of the invention;
FIGS. 19 and 20 are sectional views taken along lines 19--19 and 20--20, respectively, of FIG. 16; and
FIGS. 21 and 22 are side elevational views (respectively,) of the adjuster and main pawls, respectively, of FIG. 16.
DETAILED DESCRIPTION
Referring first more particularly to FIGS. 1-4, the adjuster pawl 3 of a self-adjust parking brake system includes a pawl tooth 3a that is adapted to engage the teeth 5a of adjuster ratchet 5. In FIG. 1 the pawl tooth 3a is in frictional partial engagement with the rear edge of a ratchet tooth 5a in a load-carrying condition, and FIG. 2 shows the pawl and ratchet teeth in an undesirable top-on-top non-load carrying condition. FIG. 3 illustrates the pawl tooth 3a in frictional partial engagement with the front edge of the ratchet tooth 5a. In this enlarged view, the self-seat, tip-on-tip, skip-through and top-over portions 5b, 5c, 5d and 5e, respectively, of the front side edge of the ratchet teeth are identified, similar portions being contained on the rear side edges of the ratchet teeth. FIG. 4 illustrates the pawl tooth in the preferred fully-engaged condition relative to the ratchet teeth.
Referring now to FIGS. 5-8, the parking brake arrangement is of the automatic cable-slack removing self-adjust type including a foot pedal lever 2 pivotally connected by pivot pin 4 with a housing 6 for operating the parking brake cable 8 via automatically operable cable slack removing means 10. The cable slack removing means includes a cable tract member 12 secured to an adjuster ratchet 14 that rotates freely about pivot axis 4, which adjuster ratchet is biased in the counterclockwise cable slack removing direction by spiral adjuster spring 16 mounted concentrically about pivot shaft 4. Adjuster pawl 18, which is pivotally connected with foot lever 2 by pivot pin 20, has a pawl tooth 18a that is normally biased into engagement with the ratchet teeth 14a by pawl spring 22 (which biases the adjuster pawl in the counterclockwise direction relative to lever 2).
Sector gear 26 is secured to foot pedal 2 for cooperation with the teeth 28a of a gear drum 28 the outer periphery of which is in concentric engagement with the inner surfaces of the turns of helical clutch spring 30. One end 30a of the helical clutch spring is clamped to the housing 6, while the other end 30b of the clutch spring is arranged for engagement by the release end 34a of the release lever 34 that is pivotally connected by pivot pin 36 with housing 6, and is pivoted in the clockwise parking brake release direction by release lever 38 that is biased by spring 40 toward the spring-clutch-engaged position.
According to a characterizing feature of the invention, the self-adjust cable slack removing means 10 further includes stationary cam-out pin means 44 for disengaging the adjuster pawl 18 from the adjuster ratchet 14, and stationary cam-in pin means 46 for assuring deep-seated full engagement between the adjuster pawl tooth 18a and ratchet teeth 14a (corresponding with the fully-engaged condition of FIG. 4) as the foot pedal lever 2 is depressed toward the parking brake fully-engaged condition. As will be developed below, the spacing distance between the stationary cam-out and cam-in pins--which are each secured to the housing 6--is critical. The cam-out pin also functions as the resilient bumper for stopping pivotal movement of the foot lever 2 in the brake-releasing direction.
OPERATION
Referring now to FIGS. 9 and 10, assuming that the parking brake mechanism is initially in the fully-released condition, upon the application of force to foot pedal 2a, lever 2 is pivoted in the counterclockwise direction to tension the parking brake cable 8, and the cam-out edge 18b on adjuster pawl 18 is progressively removed from stationary camout pin 44 (i.e., during the first 3° to 5° of travel of the foot pedal, as shown by points T 1 and T 2 on the pedal travel curve). When contact with the cam-out pin ceases, the adjuster pawl pivots into one of the four possible engagement conditions of FIG. 1-4, depending on the instantaneous relationship between the adjuster pawl and ratchet. The point as which the self-adjust pawl cam-out surface disengages from the stationary component of a cam-out function initiates the timing overlap function of the engagement sequence. The reaction of the mechanism to the cam-in dwell timing overlap is dependent upon the type of engagement established during initial pedal travel, i.e. fully engaged, tip-on-tip or top-on-top condition.
If full engagement of the pawl tooth were to occur (FIG. 4), travel of the pedal 2 would be transmitted directly to cable 8 via pawl 18, ratchet 14, and cable track member 12. Owing to the known one-way operation of clutch spring 30 on drum 28, return movement of the pedal in the clockwise brake-releasing direction is prevented.
In the event that a rear edge tip-on-tip condition is obtained with the corresponding ratchet tooth (point 3 on the travel curve), the low-lever frictional force V f between the pawl and the tip-on-tip portion (4c in FIG. 3) is sufficient to carry the load as the pedal is further displaced toward the initial cam-in contact point T 7 , wherein cam-in surface 18c engages the cam-in pin 46, and the low-level tooth-on-tooth frictional force V f is overcome by the sum of the adjuster pawl spring force V aps and the cam-in force V ci .
In the event that a top-on-top (point T 4 ) or a front edge tip-on-tip condition (point T 5 ) is obtained between the pawl and ratchet teeth, during further movement of lever 2 in the brake-applying direction, the cable tension V c progressively increases relative to the constant frictional force V f , the pedal force V p , and the adjuster spring force V as , whereupon when the sum of the cable tension V c and adjuster pawl spring force V aps exceeds that of the opposing forces, the pawl tooth is displaced toward the position (point T 6 ) at which the pawl is arranged for initial contact (point T 7 ) with the cam-in pin 46. The cam-in pin 46 then applies the force V ci to the cam-in edge 18b of adjuster pawl 18, whereupon the pawl tooth 18a is placed in the fully engaged condition of FIG. 4. Thus, the pawl is fully engaged with the ratchet prior to movement of the foot lever 2 to the skip-through point T 9 , at which point the pawl might otherwise fail to enmesh fully with the ratchet teeth. The pedal continues to be depressed toward the brake fully applied condition, whereupon the lever 2 is maintained against pivotal movement in the opposite direction by the cooperation between clutch spring 30 and gear drum 28.
Upon release of the parking brake by pulling on the handle 41 of release lever 40, leg 30b of clutch spring 30 is displaced to expand the clutch spring turns relative to the periphery of drum 28, whereupon the foot lever 2 is pivoted by the tension of cable 8 toward the initial brake fully-released position. Cam-out pawl surface 18a engages cam-out pin 44 to pivot pawl 18 in the clockwise direction, thereby to disengage the adjuster pawl tooth 18a from the ratchet teeth 14a. Spiral adjuster spring 16 then expands to rotate the cable track member 12 and ratchet 14 in the counterclockwise direction, thereby to remove slack from cable 8. The adjuster pawl normally remains disengaged until the reapplication of force to the brake pedal 2a.
In the event that the cable tension is relatively great, and/or the material of the cam-out pin/bumper 44 is relatively resilient, a bounce-back condition may occur during which the lever 2 bounces back to the maximum bounce-back point 11 of FIG. 10, whereupon the pawl cam-out surface 18a is disengaged from cam-out pin 18a, and adjuster pawl 18 is pivoted by pawl spring 22 to effect engagement between pawl tooth 18a and an associated pair of ratchet teeth 14a.
Thus, in accordance with a characterizing feature of the present invention, the spacing distance of the cam-in pin 46 from cam-out pin 44 is critical to applicant's desired adjuster operation. More particularly, the spacing distance K of FIG. 10 must be at least as great as the distance between the minimum cam-out point T 2 and the top-off point 4, and preferably greater than the distance between the minimum cam-out point T 2 and the maximum bounce back distance D is provided between maximum bounce back position T 11 and minimum cam-in position T 7 .
Of course, the dimensions have been greatly exaggerated in FIGS. 3 and 10 for purposes of explanation. In actual practice, the distance 5e in FIG. 1 is on the order of 0.003 inch to 0.004 inch, the distance 5d is less than about 0.001 inch, and the distance 5c is about 0.004 to 0.005 inch. The angle of travel of foot-lever 2 between the brake fully-released and fully-applied positions is about 65° . The cam-in pin 46 is carried by the housing 6 as shown in FIG. 7, and the resilient bumper/cam-in pin 44 is mounted between the housing 6 and the fixed housing cover 6a.
Referring now to FIGS. 11-15, a second foot-lever-operated brake mechanism is disclosed in which the means for maintaining the foot lever 102 in the brake fully-engaged position 102a includes a main ratchet 126 connected with the lever 102, and a main pawl 180 biased in the ratchet-engaging direction by spring 182 for pivotal movement about fixed pivot pin 184 on the housing 106. Release rod 138 pivots release lever 134 about fixed pivot pin 184 to cause the lever extremity 134a to disengage the main pawl tooth 180a from the main ratchet teeth 188a of main ratchet 188 carried by foot lever 102.
Adjuster pawl 118 is pivotally connected with foot lever 102 by fixed pivot pin 120, said pawl having a pawl tooth 118a (FIG. 15) which is normally biased into engagement with teeth 114a of adjuster ratchet 114 by adjuster pawl spring 119. The adjuster pawl 118 has a cam-out edge 118b for engaging the stationary resilient bumper 144 which also serves as a cam-out pin, and a cam-in edge 118c for engaging the cam-in pin 146 which is secured to housing 106, as shown in FIG. 14.
The operation of this foot lever embodiment is similar to that of the FIG. 5 embodiment. The spacing distance between the cam-out pin or bumper 144 and the cam-in pin 146 is greater than the distance between the minimum can-out point 2 of FIG. 10) and the maximum bounce back point (11 of FIG. 10), thereby to define the dwell distance D 2 shown in FIG. 11. In this embodiment, the angular displacement of foot lever 102 between the fully-released position and the fully-applied position is 79°.
Referring now to the hand lever embodiment of FIGS. 16-22, a single pin 247 serves as both the cam-out and cam-in pin for the adjuster pawl 218 which pivots about fixed pivot 220 on hand lever 202. Hand lever 202 pivots about pivot pin 204 mounted on housing 206, which hand lever is maintained in the brake-applied position by the cooperation between tooth 280a of main pawl 280 also pivoted on pivot pin 220, and the corresponding teeth of main ratchet 188 secured to the housing 206. As hand lever 202 is pivoted upwardly about main pivot pin 204 mounted between housing 206 and lever member 206a, adjuster pawl 218 is pivoted by adjuster pawl spring 222 in the clockwise direction to effect engagement between adjuster pawl tooth 218a and the corresponding teeth of adjuster ratchet 214. When the cam-in surface 218c of the adjuster pawl engages the cam-in side of the cam-in pain, the pawl 218 is pivoted into full enmeshing engagement with the adjuster ratchet 214. As the lever continues to be pivoted in the clockwise direction through 64° toward the brake fully-applied position, the brake cable 208 is tensioned to apply the parking brake, the lever being maintained in place by the cooperation between main pawl 280 and main ratchet or sector 288.
To release the parking brake, button 290 is inserted to pivot main pawl 280 in the clockwise direction about pivot 220, thereby to disengage main pawl tooth 280a from the teeth of main ratchet 288. Owing to the tension of brake cable 208, the cable track member 212, adjuster ratchet 214 and adjuster pawl 218 are displaced until the lever returns to its initial brake off position, whereupon cam-out surface 218b on the adjuster pawl 218 engages the cam-out side of pin 247, thereby to disengage adjuster pawl 218, whereupon adjuster spring 216 expands to remove slack from brake cable 208.
It is important to note that the effective distance between the cam-out and cam-in surfaces on the pawl relative to pin 247 is such as to provide a sufficient dwell overlap distance D 3 between the top-off position and the initial cam-in position as to insure that the cable tension has prevented any possibility of the adjuster pawl tooth 218a being in a top-on-top or front ends tip-on-tip position relative to the associated adjuster ratchet tooth.
It should be mentioned that the bounce-back travel of the lever (from T 2 to T 11 in FIG. 10) cannot exceed the lever travel distance to skip-through (i.e., from point T 2 to point T 9 .
While in accordance with the provisions of the Patent Statutes the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent that changes may be made without deviating from the inventive concepts set forth above.
|
An improved non-jamming self-adjust pawl and ratchet mechanism for use in an automotive parking brake system or the like, includes cam-out and cam-in devices that are spaced to define an overlap dwell distance to insure suitable engagement between the adjuster pawl and the adjuster ratchet as a foot or hand brake operating lever is pivoted from a brake disengaged position toward a brake fully-engaged position. In the case of the foot-operated lever, the spacing distance between the cam-out and cam-in devices is greater than the bounce-back travel distance of the lever upon the removal of cable tension load thereon.
| 8
|
FIELD OF THE INVENTION
[0001] The present invention relates to a safety pillow, and especially to a pillow device of a car seat which is helpful to the safety of a passenger sleeping in a moving car.
BACKGROUND OF THE INVENTION
[0002] Currently, the primary concerns in the decoration of a car put a great emphasis on the elegance and practice use. Most of the designs are concentrated on the instrument panel, decorating textures, safety air bag, safety strip, comfort of the seat of the driver. However, the sleeping in the car which troubles the passengers has no means to solve this problem. Therefore, the safety and comfort in sleep is a problem eagerly to be resolved.
[0003] In the prior art, almost no design aims at the passenger pillow of a car seat. Referring to FIG. 1, a lateral view of a general car seat is illustrated. In the prior art, the pillow 2 is arranged at the upper side of a car seat 1 by a supporting rod 2 . The elevation of the pillow 2 is adjustable to meet the head of a passenger. However, most of the pillow is designed to protect the passenger from being impacted, while the pillow in the prior art without any neck supporter and the function of preventing the head to turn laterally so that as the passenger sleeps as the car is driven, the head or neck of the passenger is possible hurt or feel ache due to dramatic vibration from turning or braking abruptly.
[0004] Thus, the current pillow of a car seat has a serious defect. This defect will induce a dramatic accident as the passenger sleep in a car. Since as a passenger sleeps in a car, he (or she) is generally without any alert to the accident from the environment. Therefore, the head and neck of the passenger is possible hurt. Moreover, passengers often feel uncomfortable, moreover, has aches in head and neck. These are caused from an uncomfortable sleep in the car.
[0005] From a statistic result, most of passengers must sleep for a while in a long period as taking a car. Therefore, there is an eager demand for a novel pillow device which may improve the defect in the prior art.
[0006] Referring to FIG. 2, an inflation device for protecting the neck of passenger is illustrated. The inflation device 3 is formed with an opening which may wind around the neck of the passenger to avoid the neck to be pressed since the head turns aside. However, this device will make the user feel uncomfortable because of being wound around. Moreover, as the head turns aside, the beats of the artery in the head will make the passenger feel uncomfortable and is not beneficial to sleep. Furthermore, since device 3 directly winds around the neck of the passenger, the defect of sleeping laterally of a passenger can not be corrected. Therefore, there is an eager demand for a pillow device to help the user to sleep in a correct pose.
SUMMARY OF THE INVENTION
[0007] Accordingly, the primary object of the present invention is to provide a pillow device which can support the neck of the passenger and prevent the head of the passenger to turn aside.
[0008] Another object of the present invention is to provide a pillow device which can be attached to a car seat so as to support the neck of the passenger and prevent the head of the passenger to turn aside to press the nerves in the neck.
[0009] A further object of the present invention is to provide a pillow device which may improve the car seat, and can support the neck of the passenger and prevent the head of the passenger to turn aside.
[0010] The present invention provides a pillow device which can improve the defects in the prior arts, such as the pillow in the prior art without any neck supporter and the function of preventing the head to turn laterally so that as the passenger sleeps in a moving car, the head or neck of the passenger is possible hurt or feel ache due to dramatic vibration from turning or braking a car abruptly. Therefore, the present invention provides a pillow device which can be adhered to the pillow of a car seat is disclosed. The pillow device includes an adjustable or inflatable soft portion for supporting the neck of a passenger, a head supporting portion for preventing the head to turn laterally. A ring sticky buckle serves to fix the pillow device on the pillow of a car seat.
[0011] In another embodiment, the car seat is improved so that an adjustable or inflatable soft portion for supporting the neck of a passenger, a head supporting portion for preventing the head to turn laterally is installed at lateral side of the pillow so that the car seat is more comfortable.
[0012] The various objects and advantages of the present invention will be more readily understood from the following detailed description when reading in conjunction with the appended drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a lateral view of the pillow in a prior art car seat.
[0014] [0014]FIG. 2 is an elevation view showing a prior art inflation device for protecting the head and neck of a passenger.
[0015] [0015]FIG. 3 is an exploded perspective view of the first embodiment of the pillow device in the present invention.
[0016] [0016]FIG. 4 is an assembled perspective view of the first embodiment of the pillow device in the present invention.
[0017] [0017]FIG. 5 is a perspective view showing the second embodiment of the pillow device in the present invention.
[0018] [0018]FIG. 6 is a perspective view showing the design of the embodiment of FIG. 5 being fixed to the pillow of a car seat.
[0019] [0019]FIG. 7 is a perspective view showing the pillow device of the present invention before being used.
[0020] [0020]FIG. 8 is a perspective view showing the use of the pillow device in the present invention.
[0021] [0021]FIG. 9 is a lateral view of the head strip of the pillow device in the present invention.
[0022] [0022]FIG. 10 is an elevation view showing the pillow device of the present invention with a slidable supporting frame.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The present invention will be fully described in the following with appended figures, while these descriptions are just used to cause those skilled in the art to understand the present invention instead of confining the spirit and scope of the present invention, whereas the present invention is defined in the appended claims as a part of this specification.
[0024] The present invention relates to a pillow device which is used in the condition that as the driver or passenger desires to take a rest during a period of driving a car. The pillow device is designed to protect and comfort the neck of the user.
[0025] In the present invention, a pillow device is illustrated, which includes two plastic curved plates (adjustable in width), an elevation angle adjuster (adjustable the elevation angle for protecting the neck bone), a cover filled with soft sponge and a sticky strip. The pillow device of the present invention can be attached to the seat of a car easily. The head and neck of the passenger can be fixed by the two plastic curved plates and elevation angle adjuster. Therefore, the passenger may sleep comfortably with a preferred pose without inducing the neck to bend laterally so as to put a force to the nerves of the head and neck. As a consequent, the passenger has a good sleep. Meanwhile, as the car is moving, the passenger may avoid to suffer from dramatic jumps and vibrations during turning or braking a car.
[0026] At first, with reference to FIG. 3, an exploded perspective view of the first embodiment of the pillow device in the present invention is illustrated therein. In this embodiment, the pillow device 10 includes a first retaining plate 11 , a second retaining plate 12 and a cover liner 15 . The lateral side of the first retaining plate 11 extends to be formed as a slightly vertical first supporting plate 13 . The supporting plate 13 has a through hole 131 . Sticky strips 16 , 17 are arranged on the first retaining plate 11 . The second retaining plate 12 is attached with a soft pad. An elevation angle adjuster 18 is arranged within the pad. The adjusting way of this elevation angle adjuster 18 may be an inflation type, an blowing type, or a mechanic type so as to be formed with an protrusion for adjusting the elevation angle and height for supporting the neck bone. The lateral side of the second retaining plate 12 extends out so as to be formed as a slightly vertical second supporting plate 14 . The supporting plate 14 has a through hole 141 . The first and second retaining plate 11 , 12 have sticky surfaces which serve to combine the first and second retaining plate 11 , and 12 together. The cover liner is made of soft material. After the first and second retaining plates 11 and 12 are combined, the left and right end portions 151 , 152 of the liner can cover the first and second supporting plates 13 and 14 , and thus the head of the passenger can be properly retained in the first supporting plate 13 and second supporting plate 14 .
[0027] The attachment of the first retaining plate 11 and second retaining plate 12 will be further described herein. The upper surface of the bottom of the first retaining plate 11 and the lower surface of the second retaining plate 12 are arranged with sticky surfaces for sticking the two retaining plate together. After the two retaining plates 11 , 12 are combined, the passenger may adjust the distance between the two supporting plates 13 and 14 for matching the width of the head. Referring to FIG. 4, a perspective view showing the combined first retaining plate 11 and second retaining plate 12 is illustrated. The dashed lines show the left and right end portions 151 and 152 of the cover liner 15 covering on the first and second supporting plates 13 and 14 so that the head of the passenger may retain between the first retaining plate 11 and second retaining plate 12 comfortably. The two through holes 131 and 141 are helpful to the hearing ability of the passenger.
[0028] In using the pillow device according to first embodiment of the present invention, at first, the first retaining plate 11 is fixed to the pillow of a car seat by sticky strips 16 and 17 . The sticky strips 16 , 17 are place at upper and lower sides of the pillow and are sticky to one another at the rear side of the pillow so that the first retaining plate 11 tightly adheres to the front side of the pillow. Next, the elevation angle adjuster 18 of the second retaining plate 12 are adjusted, and by electrically charging or mechanically adjusting, a protrusion is formed. Then, the second retaining plate 12 is sticky to the first retaining plate 11 so that the two retaining plates 11 , 12 are combined together. Finally, the cover liner 15 covers the two retaining plates 11 , 12 as so to be formed with a combination shown in FIG. 6.
[0029] Referring to FIG. 5, a perspective view of the second embodiment of the present invention is illustrated. In this embodiment, from one lateral view, it is shown that the pillow device 20 has a ␣ shape. A PVC material with a middle hardness and a thicker thickness is used as the material for supporting an air bag or a soft pad thereon. In a preferred embodiment of the present invention, a plastic sheet with a thickness of 0.5 mm to 2 mm and a hardness of 25 to 35 degrees is used as the material at the back sides of the bottom and two lateral sides, while a further plastic sheet with a thickness of 0.1 mm to 1 mm and a hardness of 40 to 60 degrees is used as the material at the front sides of the bottom and two lateral sides. The pillow device 20 has a plane portion. Two ends thereof extend upwards to be formed with slightly vertical supporting plates 21 and 22 . The inner surface of the two supporting plates 21 and 22 are attached with an electric charged air bag or a soft pad. The upper surface at the plane portion between the two supporting plates 21 and 22 has fixed soft pad 231 and a soft protrusion 232 for adjusting the elevation angle. The protruding height of the protrusion can be adjusted by an inflation or a mechanically way for supporting the head and neck of a passenger. The lower surface of the plane portion is installed with sticky strips 24 and 25 the use of which are identical to that of the sticky strips 16 and 17 in the first embodiment. Besides, the two supporting plates 21 and 22 are installed with through holes 211 and 221 for retaining the hearing ability of the passenger to be comfortable.
[0030] Now, referring to FIG. 6, in the use of the pillow device 20 according to second embodiment of the present invention, the pillow device 20 of the present invention can be fixed to the pillow 2 of a car seat 1 directly by the sticky strips 24 , 25 , and the pillow device 20 is retained in front of the pillow 2 so that the passenger may retain the head between two supporting plates 21 and 22 comfortably. Furthermore, the air bag or pad with a soft material at the inner surface thereof will sustain the head to resist against the pillow device comfortably. The comfortable protrusion 232 resists against the neck of the head so as to protect the neck portion.
[0031] With reference to FIGS. 7 and 8, perspective views of the pillow device according to the present invention used in the seat of a car before using and in using, respectively, are illustrated therein. In this embodiment of the present invention, the pillow of a car seat 1 is directly changed as a pillow device 30 . At first, referring to FIG. 7, the pillow device 30 has a soft body. The left and right sides of the body have movable supporting plates 31 and 32 . In this embodiment, two supporting plates 31 , 32 are movably and rotatably fixed to the two lateral sides of the body by a fixing shaft 321 . A protecting soft pad for protecting and fixing two sides of the neck bone is formed on the respective surface of the two supporting plates 31 , 32 . When the two supporting plates 31 , 32 are rotated through one angle, stoppers are formed at two sides of the body so that the head of the passenger is retained between the two supporting plates 31 , 32 to has an optimum pose. The neck portion will not bend laterally to press the nerve of the head. Besides, the lower side of the body of the pillow device is installed with a soft protrusion 33 for adjusting the elevation angle thereof. The embodying way of the protrusion 33 is by an inflation or a mechanic way to adjusting the height thereof for supporting the neck portion thereof.
[0032] In order to increase the safety of a passenger which sleeps for a while when a car moves, other than the safety pillow device of the present invention, a further hat or head strip can be installed. With reference to the schematic view showing in FIG. 9, the aforesaid embodiments can be further arranged with a hat or head strip 34 at the pillow device. The hat or the head strip 34 can be separated from the pillow device, and if desired, it can be adhered to the pillow device through buckling rings or sticky strips. A telescopic device is installed at the connection between the hat or the head strip 34 and the pillow device in order to protect the passenger from colliding forwards due to an impact of the car, or to avoid the head to collide the top of the car.
[0033] Therefore, by the design of the hat and head strip, the force applied to the head due to a collision is reduced so that the head and neck are well protected. Besides, the sizes of the hat and head strip are adjustable for suiting the size of the passenger.
[0034] Although the present invention has been described with reference to the preferred embodiments, it will be understood that the invention is not limited to the details described thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. For example, in the design of the width of the pillow device, the two supporting plates at lateral sides can be designed to be adjustable and inclined inwards, so that the width therebetween is adjustable. If the cost is an important consideration, a simple hard sponge ear cover can be used. Two sponge covers enclose the left and right supporting air bags or soft bags so that the width of the pillow device become small for matching the head size of the passenger. Furthermore, according to the pillow device 20 in the second embodiment of the present invention, the supporting plates 21 , 22 can be changed to become movable to cause the supporting plates 21 , 22 each are combined with a sliding plate, as shown in FIG. 10; for example, the knife piece of an article knife, and then it is further coupled to the body of the soft pillow so that the two supporting plates 21 and 22 has a adjustable distance therebetween for meeting the requirement of the passenger. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.
[0035] The pillow device according to the present invention not only has the original function of a pillow, but also may protect the head and neck of the passenger so as to improve the quality of sleep. The defect that the prior art pillow which can not well protect the head and neck of the passenger is effectively improved. The pillow device of the present invention has a simple structure. In embodying, it can easily combine with the seat of a car with a little cost.
|
A pillow device can be adhered to the pillow of a car seat is disclosed. The pillow device includes an adjustable or inflatable soft portion for supporting the neck of a passenger, a head supporting portion for preventing the head to turn aside. A ring sticky buckle serves to fix the pillow device on the pillow of a car seat so that other than the original function of a pillow, the pillow device of the present invention has a further function of protecting the head and neck of a passenger so as to improve the quality in sleep.
| 1
|
BACKGROUND OF THE INVENTION
The invention relates to a process for the production of a composite camshaft and an apparatus suitable for use in the production process.
A known process for the production of composite camshafts is disclosed in German Application No. DE-A1-3209980 wherein cam elements and bearing elements produced by sintering are fixed on a shaft by means of small pins or tubes arranged in radial bore holes. After fixing the elements in place, the camshaft is sintered at a predetermined temperature so as to allow the cam elements and bearing elements to become integrally bonded with the shaft.
The process for making the radial bore holes in the shaft, the angular position of which has to be very exact, is very laborious and requires a number of mechanical operations including an alignment of the parts during the drilling operation and also during the subsequent fixing in position operation, which is disadvantageous for economical reasons.
The object of the present invention is the development of a process for the production of a composite camshaft which makes possible a simple alignment and fixing in position of the cam elements and bearing elements on the shaft in an efficient operation. The present invention is also drawn to an apparatus for carrying out the process.
SUMMARY OF THE INVENTION
The foregoing objects are achieved by way of the process of the present invention for the production of a composite camshaft having a plurality of cam elements and a plurality of bearing elements mounted on a shaft at a desired location and a desired orientation comprising providing an elongated shaft having a longitudinal axis and an outer circumferential surface configuration, providing a plurality of cam elements and bearing elements wherein each of the cam elements and bearing elements are provided with an internal bore having a size and configuration substantially similar to the outer circumferential configuration of the shaft, positioning the plurality of cam elements and the plurality of bearing elements successively on the shaft, locating a first of one of the plurality of cam elements and the plurality of bearing elements at a desired location along the longitudinal axis of the shaft, orienting the first of one of the plurality of cam elements and the plurality of bearing elements at a desired orientation on the outer circumferential surface of the shaft with respect to the longitudinal axis thereof, fixing the first of one of the plurality of cam elements and the plurality of bearing elements on the shaft, and repeating the locating, orienting and fixing steps until all of the plurality of cam elements and bearing elements are secured on each shaft. The apparatus for carrying out the process comprises first motor means for rotatably supporting a shaft for rotation about a longitudinal axis of the shaft, gripping means mounted proximate to the shaft for selectively holding the cam elements at desired locations along the axis of the shaft, securing means associated with the gripping means for securing the selectively held cam elements to the shaft, second motor means for displacing the gripping means and the securing means along the axis of the shaft, and control means for selectively actuating the first and second motor means for locating and orienting the cam elements on the shaft.
BRIEF DESCRIPTION OF THE DRAWING
The single figure shows a diagrammatic representation of an apparatus for the automatic positioning and fixing in position of cam elements on a camshaft in accordance with the process of the present invention.
DETAILED DESCRIPTION
The apparatus has a receiving device 10 for the camshaft 1, which consists of a preferably hollow shaft 2 and cam elements 3 and bearing elements 4 arranged thereupon.
The receiving device 10 has a chucking fixture 12 which is rotatably by first motor means in the form of a rotary drive 11 and, at the other end, a tailstock with a center 13, for keeping a shaft 2 rotatably supported about axis 16. On the chucking fixture 12 there is arranged an angle of rotation measuring device 14, which is effectively connected to a microprocessor 15.
Parallel to the axis of rotation 16 there is arranged a longitudinal guide 17, on which a gripping device 19 is longitudinally displaceable by means of a second motor means or drive 18. A displacement measuring device 20 is effectively connected to the microprocessor 15. The first and second drives 11 and 18 are likewise effectively connected to the microprocessor 15.
A securing means 21 in the form of a welding or soldering device is arranged to be longitudinally displaceably together with the gripping device 19. The securing means 21 is designed for the application of at least three weld or solder points evenly distributed round the circumference on one end face of the cam elements 3. The welding or soldering device may also be arranged longitudinally displaceably on a second guide if desired, which requires a further drive and displacement measuring device.
The process for the production of the camshaft is as follows.
The cam elements 3, and if desired also the bearing elements 4, are pushed onto the shaft 2 in the desired number and sequence, where they are aligned in one direction alongside one another at one end of the shaft. The cam elements, preferably made of a hard casting, each have a bore hole which has a slight play with respect to the preferably smooth shaft, which is achieved by prior mechanical working, for example by grinding. The shaft 2, provided with the cam elements 3 and bearing elements 4 threaded on, is located in the receiving device 10 and microprocessor 15 is actuated which causes the first cam element 3 located near the free end of the shaft to be seized by the gripping device 19 and brought into the desired position on the shaft by longitudinal displacement thereof by means of the gripping device and drive 18. Thereafter, by turning of the shaft 2 by means of the rotary drive 11 the desired orientation of the cam element is accomplished.
As the welding or soldering device 21 is likewise brought into the operational position at the same time as the longitudinal displacement of the gripping device 19, the corresponding weld or solder points can be applied, for example by the extension of preferably three weding or soldering arms, to one end face of the cam element 3 for the fixing of the cam element in the correct position.
Thus, all cam elements successively or, if two having the same circumferential direction are alongside each other, two cam elements at once, are brought into the specified position and fixed there by means of a tack connection.
Once all cam elements have been fixed in position, the firm connection of the cam elements 3 to the shaft 2 is established by a circumferential weld or solder connection on at least one end face of each cam element 3. This is preferably performed in a separate welding or soldering device or by means of a welding or soldering device additional arranged in the previously described apparatus.
It is to be understood that the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible of modification of form, size, arrangement of pafts and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims.
|
A process for the production of composite camshafts comprises the selective positioning of a plurality of cam elements on a camshaft and orienting the cam elements at a desired location with respect to the central axis of the shaft and thereafter securing the cam elements in place on the shaft.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Application Ser. No. 62/090,639 filed on Dec. 11, 2014, the contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates generally to heat producing devices, and more particularly to a vaporization lighter.
BACKGROUND
[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0004] According to recent estimates, more than 42.1 million Americans routinely smoke tobacco and/or other types of herbs which are typically packed within a pipe, a cigarette, or a cigar, for example. In either instance, these and other such smoking materials are typically burned by a lighter, at which time the smoke and/or soot produced by the burning process is inhaled by the smoker.
[0005] Although this process has been the norm for hundreds of years, it is well known and documented that long term exposure to such smoke has extremely deleterious effects on human lungs, and can cause diseases such as COPD, emphysema, chronic bronchitis, and/or lung cancer, for example. In an effort to reduce the amount of smoke and soot that is generated by applying a direct flame to the smoking material, recent advances in technology have seen the introduction of various heat sources (e.g., vaporizers) that can reduce lung irritation, improve the taste of the smoking material, and reduce lingering odors associated with the smoking material.
[0006] Unfortunately, owing to the high cost, large size and uneven results produced by such devices, many smokers continue to utilize a traditional lighter to burn their smoking material. Accordingly, it would be beneficial to provide a small, lightweight and durable vaporization lighter that does not suffer from the drawbacks described above.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a vaporization lighter device. One embodiment of the present invention can include a heat source such as a jet flame lighter, for example, that is capable of producing a flame and directing the same in a horizontal direction. The invention can also include a flame filter that is positioned in line with the heat source via the main body.
[0008] In one embodiment, the flame filter includes a heat conducting chamber that is filled with a non-combustible filter material. An aperture can be disposed along the center of the chamber and allows the flame produced by the heat source to directly impact the filter material. Openings along each end of the filter chamber draw air across the filter material, which are directed onto a smoking material.
[0009] Another embodiment of the present invention can include a removable and insulated cap that can encompass the flame filter. Yet another embodiment of the present invention can also include a stir stick that is removably secured to the main body and/or the cap.
[0010] This summary is provided merely to introduce certain concepts and not to identify key or essential features of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Presently preferred embodiments are shown in the drawings. It should be appreciated, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
[0012] FIG. 1 is an exploded parts view of the vaporization lighter device that is useful for understanding the inventive concepts disclosed herein.
[0013] FIG. 2 is a perspective view of the main body of the vaporization lighter device, in accordance with one embodiment of the invention.
[0014] FIG. 3 is a side view of the flame filter of the vaporization lighter device, in accordance with one embodiment of the invention.
[0015] FIG. 4 is a perspective view of the vaporization lighter device, in accordance with one embodiment of the invention.
[0016] FIG. 5 is a side view of the vaporization lighter device in operation, in accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] A vaporization lighter is described below with respect to the figures. While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the description in conjunction with the drawings. As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which can be embodied in various forms.
[0018] Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the inventive arrangements in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the invention.
[0019] Identical reference numerals are used for like elements of the invention or elements of like function. For the sake of clarity, only those reference numerals are shown in the individual figures which are necessary for the description of the respective figure. For purposes of this description, the terms “upper,” “bottom,” “right,” “left,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in FIG. 1 .
[0020] As described herein, the term “removably secured,” and derivatives thereof shall be used to describe a situation wherein two or more objects are joined together in a non-permanent manner so as to allow the same objects to be repeatedly joined and separated.
[0021] As will be known to those of skill in the art, the term “vaporization” and derivatives thereof refers to a process of providing heat to a smoking material at a sufficient temperature to cause the oils and crystalline constituents of the material gasify. This temperature is usually within the range of approximately 300-425° F., and is performed without exposing the material to a direct flame. In this regard, when a smoking material is vaporized, the product can be inhaled without the carcinogens that would otherwise be generated by burning the material.
[0022] FIG. 1 is an exploded parts view of one embodiment of a vaporization lighter device 10 that is useful for understanding the inventive concepts disclosed herein. As shown, the device 10 can include a heat source 15 , a main body 20 , and a flame filter 30 .
[0023] In the preferred embodiment, the heat source 15 can include or comprise a butane-fueled torch flame lighter having a lighter body 15 a, a flame activation button 15 b and a flame igniter/dispenser 15 c along the top end thereof. Of course, the device is not limited to the use of a torch flame lighter, as the heat source 15 can include or comprise any number of different devices that are capable of generating a sustained heat output in the horizontal direction of at approximately 2,600° F. As will be described below, the ability of the heat source to produce a high temperature flame horizontally is particularly important for a highly efficient device.
[0024] The main body 20 can function to receive and align the heat source 15 and flame filter 30 in a generally perpendicular orientation to one another. As shown in FIG. 2 , one embodiment of the main body can include an elongated, hollow and generally rectangular member 21 having an open bottom end 21 a, an open top end 21 b, and a continuous lip 21 c for receiving a removable cap 23 .
[0025] The main body is designed to receive heat source 15 , which can be inserted through the open bottom end 21 a, until the heat source button 15 b is located within the main body opening 21 d. Although not illustrated, any number of ridges or other such channels can be provided within the hollow central portion of the main body, so as to ensure the heat source fits tightly within the main body, thereby preventing an inadvertent separation of the same.
[0026] As described herein, the main body 20 can preferably be constructed from a durable, lightweight and non-heat conducting material such as plastic, for example, and can also include any number of decorative elements such as various colors, markings, words, shapes, symbols, logos, designs, lights, types of materials, texturing of materials, patterns, images, and the like. These decorative elements can be secured onto and/or into the main body in accordance with known techniques so as to be flush with the surface of the main body or can be raised/protruding outward from the main body so as to give a three dimensional effect.
[0027] As shown, one or more filter holders 22 can extend upward from the rectangular member 21 and can function to engage the below described flame filter 30 , so as to securely position the same above the open top end 21 b. In this regard, the filter holder can be constructed from the same material as the main body, or can be constructed from a different material, so as to accommodate mating with the flame filter.
[0028] The cap 23 can include a generally hollow member having an opening 23 a along the bottom end. The cap includes a dimension that corresponds to the lip 21 c of the main body, so as to be removably positioned thereon (See arrow a). When so positioned, the cap can function to enclose the flame filter, so as to prevent inadvertent contact between a device user and the extremely hot filter 30 . As such, the cap 23 will also preferably be constructed from a lightweight non-heat conducting material, and can also include additional layers of insulation which can be provided within the interior portion of the cap.
[0029] In one embodiment, the cap 23 can also include a sleeve 24 for receiving a stir stick 25 , as shown by arrow b. The stir stick can be utilized to periodically stir a smoking material that is being heated with the device. Of course, other embodiments are also contemplated wherein the sleeve and stir stick are positioned at other locations, such as the rectangular member, for example.
[0030] Although described above with respect to a particular shape and/or material, this is for illustrative purposes only, as those of skill in the art will recognize that the main body can include virtually any shape, and can be constructed from any number of different materials that are suitable for engaging and aligning the heat source 15 and the flame filter 30 in a generally perpendicular relationship, so as to allow the device to perform the described functionality. Moreover, although described for use with a removable heat source, other embodiments are also contemplated wherein the heat source can be permanently incorporated within the main body.
[0031] FIG. 3 illustrates one embodiment of the flame filter 30 that includes a chamber 31 having a filter material 35 positioned therein. As shown, the chamber 31 can comprise an elongated, generally tubular member having openings 31 a and 31 b along the ends thereof. An aperture 32 can be positioned along the center of the chamber 31 , so as to allow a portion of the filter material 35 contained within the chamber to be exposed.
[0032] In the preferred embodiment, the chamber 31 will be constructed from steel, and opening 31 a will include a diameter that is less than the diameter of the opening 31 b. The chamber 31 can be permanently connected to the distal end of the filter holder 22 via an adhesive bond, welds, or via physical connectors such as nuts and bolts, for example. Of course the chamber is not limited to any particular construction material, shape or attachment mechanism. To this end, any number of other metals and/or heat conducting materials are also contemplated, and the openings may each include virtually any diameter.
[0033] The filter material 35 can be positioned within the chamber and will span across the entirety of the aperture 32 . The filter material is preferably constructed from a non-combustible and generally porous material such as silicon carbide, glass particles, and/or stacked porous discs, for example. As will be described below, the filter material spanning the aperture will be in direct contact with the flame, and can function to absorb the heat in a manner similar to coal, so as to maintain a high temperature for extended periods of time. The filter material also functions to prevent the flame itself from exiting the chamber openings.
[0034] In various embodiments, it is preferred that the filter holder 23 include a length that is sufficient to position the flame filter approximately 0.25 and 1.25 inches, for example, from the flame dispenser portion 15 c of the heat source. When used in the preferred embodiment with the illustrated torch lighter 15 , this dimension positions the flame filter within the top ⅓ of the produced flame. This position having been determined to be the most efficient placement for generating heat via the flame filter, and without allowing the flames to escape the same. Of course, other embodiments having different placement distances are also contemplated.
[0035] FIG. 4 illustrates one embodiment of the assembled vaporization lighter 10 . As shown, the flame filter is secured along the upper portion of the holder 22 , so as to align the chamber 31 in a generally perpendicular orientation with the heat source 15 . In this regard, the portion of the filter 35 located within the aperture 32 is in direct contact with the flame 5 that is produced by the heat source.
[0036] Owing to the fact that smoking materials such as tobacco, for example are typically lit from above, it is important that the device 10 be able to produce a stream of super-heated air directly downward (i.e., vertically) so as to be extremely efficient. In this regard, it is important that the heat source be able to generate a sustained flame horizontally, so as to make contact with the flame filter.
[0037] FIG. 5 illustrates one embodiment of the vaporization lighter in operation. As shown, the device 10 is preferably used wherein the body 21 is at a horizontal orientation, and the flame filter 31 at a vertical orientation. As described above, the heat source can direct a sustained flame 5 horizontally, across the length of the holder 23 and directly onto the filter material 35 that is exposed via the aperture 32 .
[0038] As the filter material gets hot, fresh air A is drawn in through the opening 31 a and passes over the filter material 35 . This process causes the air to carry the heat generated by the flame and filter material out of the opening 31 b as super-heated air H which can be directed onto the smoking material 1 . For example, when receiving a flame 5 at a temperature of approximately 2,600° F., the flame filter can produce super-heated air H at a temperature of approximately 400° F., without having to apply a direct flame to the material 1 . In this regard, the flame filter and the channel act as a heat capacitor that heats the surrounding air more than the flame alone, and allows a device user to distribute a constant stream of super-heated air on demand.
[0039] Alternatively, or in addition to the above, the opening 31 b can be placed adjacent to the bowl 2 a of a smoking pipe 2 . When so located, a user can draw the heated air H through the pipe. This action causing additional fresh air A to be drawn through the opening 31 a. Accordingly, the above described vaporization lighter device can function as a lightweight portable heat source that is capable of repeatedly generating a concentrated stream of super-heated air in a unique manner.
[0040] As described herein, one or more elements of the vaporization lighter device 10 can be secured together utilizing any number of known attachment means such as, for example, screws, glue, compression fittings and welds, among others. Moreover, although the above embodiments have been described as including separate individual elements, the inventive concepts disclosed herein are not so limiting. To this end, one of skill in the art will recognize that one or more individual elements such as the filter holder 22 and the filter chamber 31 , for example, may be formed together as one continuous element, either through manufacturing processes, such as welding, casting, or molding, or through the use of a singular piece of material milled or machined with the aforementioned components forming identifiable sections thereof.
[0041] As to a further description of the manner and use of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, 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.
[0043] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
|
A vaporization lighter device includes a heat source for producing a flame and directing the same in a horizontal direction. The heat source is perpendicularly aligned with a flame filter via a main body. The flame filter includes an elongated chamber having an open front end, an open second end, and an aperture along the central portion. A non-combustible filter material is positioned within the elongated chamber and spans the central aperture. Ambient air is drawn through the open first end, across the filter material where it absorbs heat, and leaves the second end as super-heated air.
| 5
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an on-off valve which instantly operates between an open position and a closed position. The on-off valve of this invention is particularly suitable for high-pressure fluid systems and/or those that operate with an incompressible fluid.
[0003] 2. Description of Prior Art
[0004] On-off valves are commonly used to control fluid flow. There are many types of valves suitable for fluids, gas or liquid, operating at low fluid pressures. As the fluid pressure increases, the availability of suitable valves narrows. At high fluid pressures, the selection of suitable conventional valves is significantly restricted. At pressures above 10,000 psi, which are common in water jetting processes, the suitable conventional on-off and pressure-regulating valves are reduced to a few needle valves, poppet valves, stem valves, and ball valves. These valve names indicate the shape of an internal key valving element. When the water pressure is further increased to above 20,000 psi, only stem valves, needle valves, and poppet valves can withstand the high stresses induced by the pressurized fluid.
[0005] There are several reasons why high-pressure fluid, particularly water, pose problems for valves. On-off valves commonly include a valve cavity having an inlet and an outlet, an elongated valve stem having one end inside the valve cavity and an other end outside the valve cavity, a valve port shaped to mate with the internal end of the valve stem and connected to the valve outlet, and a source of outside force connected to the external end of the valve stem, as shown in FIG. 1. The outside force is used to raise or lower the valve stem so as to close or open the valve port. One common outside force is generated by a human hand working on a lever to rotate the valve stem, which is supported by threads between the valve stem and the valve body. To close the valve, the valve lever is rotated clockwise, for example, to lower the valve stem until a tip of the valve stem tightly engages the valve port. To open the valve, the valve lever is rotated counterclockwise to raise the valve stem and to open the port. Because of the hand motion involved, the valve lever generally is rotated a quarter turn at a time. If the threads around the valve stem are fine, the valve port is generally opened quite slowly. Thus the fluid will gush out of the valve port when first opened. When the fluid is water at very high pressures, severe erosion of valve stem and valve port can occur. Once eroded, a greater outside force is required to close the valve. This excessive force can deform valve parts and if so, the valve will not perform its duty. To avoid such situation, the valve port should be opened more quickly, particularly when the fluid pressure is very high and the fluid is incompressible, such as water. In other words, the on-off valve should be open or closed instantly.
[0006] Providing a fast on-off valve operation requires a linear motion on the valve stem and the slow rotation will not suffice. This linear motion can be easily applied to a valve stem at low fluid pressures. At very high fluid pressures, this task becomes very difficult. For example, a 0.125 inch diameter valve stem positioned in a valve cavity filled with 30,000-psi water will be pushed out by a force of about 368 lb f . To push this valve stem into the valve cavity, an outside force greater than 368 lb f must be applied to the external end of this 0.125 inch diameter valve stem. This force is practical if compressed air or pressurized oil is the source and is applied by an actuator, but impractical if it is applied by a hand of a human operator. Further, the strength and support of this valve stem also become critical factors. The pounding between the valve stem and its mated port is also a concern if the valve has frequent operation. As a result, there is no good conventional instant on-off valve for use with water at very high pressures. It is one object of this invention to solve these problems by providing suitable valves.
[0007] In water jetting operations, a valve must frequently interrupt the water stream. To minimize the outside force required, the diameter of the valve stem is often very small. For example, a waterjet at 55,000 psi is currently used in industrial material-cutting operations and the waterjet must be interrupted frequently with an instant on-off valve having a compressed air operated actuator. The valve stem is commonly about 0.078 inches in diameter and mates with a valve port about 0.045 inches in diameter. This diameter ratio results in a cross-sectional area of about 0.003 square inches available for generating a valve stem lifting force necessary to open the valve, if compressed air is used only in closing the valve. This valve-lifting force fades away as the valve stem and the valve port become worn. Further, the small valve port required by a small valve stem is incompatible with many water jetting processes that require high flow rates, such as cleaning ship hulls with waterjets. It is another object of this invention to provide on-off valves without such flow rate restrictions.
SUMMARY OF THE INVENTION
[0008] Another problem with conventional on-off valves used in high-pressure water jetting processes is a frequent pounding between the valve stem and the valve port. Because the valve operating force is applied directly to the valve stem and then transmitted to the valve port upon contact, failure of these two parts will occur soon if the contact is frequent. It is highly desirable to soften the contact to eliminate severe pounding of the valving parts, particularly at high fluid pressures. It is another object of this invention to provide on-off valves that have no pounding or that significantly reduce pounding of valve parts.
[0009] Automatic pressure regulating valves are very useful in pressurized fluid systems and are often a safety valve of the system. In water jetting operations, water flow is often interrupted while the pump is driven by a diesel engine that typically operates at a constant speed. Therefore, a reliable bypass valve that can sense system pressure changes and automatically bypass a predetermined amount of water to maintain a constant system pressure is of significant value. In many waterjet cleaning operations, the water flow must be interrupted frequently. Thus, the bypass valve will also be frequently operated on and off. A conventional spring-operated pressure regulating valve is illustrated in FIG. 2, which is similar in construction to the conventional manual on-off valve illustrated in FIG. 1, except that a constant outside force from a compressed spring is applied to the valve stem. The valve stem has a diameter greater than the diameter of the valve outlet port to create a cross-sectional area differential and to generate a prescribed valve lifting force F f . When the compression spring is set against a prescribed fluid pressure P f , the valve port is closed. When the fluid pressure is increased beyond P f , the fluid induced force F f is increased, thus causing the valve stem to move up and to release some fluid. As soon as the fluid pressure is restored to below P f , the valve stem will again move down to close the valve port. This conventional setup is a main component of pressure-relief valves used in water jetting processes, despite its many known shortcomings. One serious shortcoming is the change and ultimately loss of the valve opening capability from erosion and wear of the valve stem and its mated valve seat, a situation shared by manual on-off valves.
[0010] It is one object of this invention to provide an on-off valve for use with all types of fluid, particularly incompressible fluids, at a wide range of operating pressures.
[0011] It is another object of this invention to provide an on-off valve that can be easily operated by forces generated by a human hand or foot, even at very high operating fluid pressures.
[0012] Another object of this invention is to provide an automatic valve for pressure regulating applications in high-pressure water jetting processes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] This invention can be better understood when the specification is taken in view of the drawings, where:
[0014] [0014]FIG. 1 is a partial cross-sectional view of a conventional on-off valve;
[0015] [0015]FIG. 2 is a partial cross-sectional view of a conventional on-off valve with a mechanical actuator;
[0016] [0016]FIG. 3 is a partial cross-sectional view of an on-off valve and an actuator, shown in a closed position, according to one preferred embodiment of this invention;
[0017] [0017]FIG. 4 is a partial cross-sectional partial view of an actuator, according to one preferred embodiment of this invention;
[0018] [0018]FIG. 5 is a partial cross-sectional view of the on-off valve with the actuator as shown in FIG. 3, but in an open position;
[0019] [0019]FIG. 6 is a partial cross-sectional view of an on-off valve and an actuator, in a closed position, according to another preferred embodiment of this invention;
[0020] [0020]FIG. 7 is a partial cross-sectional view of an on-off valve and an actuator, according to another preferred embodiment of this invention;
[0021] [0021]FIG. 8 is a partial cross-sectional view of an on-off valve and an actuator, according to another preferred embodiment of this invention;
[0022] [0022]FIG. 9 is a partial cross-sectional view of an on-off valve and an actuator, according to another preferred embodiment of this invention; and
[0023] [0023]FIG. 10 is a partial cross-sectional view of an on-off valve and an actuator, according to yet another preferred embodiment of this invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] [0024]FIG. 3 shows one embodiment of this invention as a lever-operated on-off valve suitable for human hand operation, even at a wide range of fluid pressures. Valve 100 of this invention has valve body 101 , cylindrical valve cavity 102 divided by bushing 103 into upper chamber 104 and lower chamber 105 . A cylindrical valve poppet 106 straddles bushing 103 and has end portion 107 positioned in chamber 104 and opposite end portion 108 positioned in chamber 105 . Valve inlet 109 is in communication with chamber 105 . Valve seat 110 inside chamber 105 has a bore in communication with valve outlet 111 . Spring cylinder 112 is engaged by threads or other connection means to valve body 101 at end 113 to plug or seal chamber 104 in a fluid-tight manner. Cam housing 114 is attached to an opposite end of spring cylinder 112 . Compression spring 115 is positioned inside chamber 104 around valve poppet 106 and urges valve poppet 106 into a position disengaged from valve seat 110 . Compression spring 116 is positioned inside spring cylinder 112 and abuts spring piston 117 at one end and abuts a cam piston 118 at an opposite end. Valve actuating pin 119 has tapered end 120 positioned inside chamber 104 and the other end abutting spring piston 117 . Cam disk 121 , positioned inside cam housing 114 , is rotatable around axial element 122 and constantly contacts cam disk 118 . Valve lever 123 is attached to cam disk 118 . Slot 124 within cam disk 119 accommodates axial element 122 . Seal assembly 125 is positioned around actuating pin 116 .
[0025] Still referring to FIG. 3, cam disk 121 of valve 100 of this invention is shaped so that its rotation around axial element 122 results in a linear movement of cam piston 118 along a central axis of valve cavity 102 . Cam piston 118 moves between a high position and a low position. In the high position spring 116 is extended and in the low position spring 116 is compressed. Movement of cam piston 118 causes spring piston 117 to move accordingly, which causes valve actuating pin 119 to move in and out of chamber 104 . At the high position, pin 119 is retracted from chamber 104 . At the low position, pin 119 is extended into chamber 104 and engages end portion 107 at a central location. Valve poppet 106 has a central fluid passage 126 that extends from end portion 107 to end portion 108 and has check valve 127 therebetween to limit the fluid flow only from chamber 104 to chamber 105 but not from chamber 105 to chamber 104 . Tapered end 120 of valve pin 119 engages fluid passage 126 so that passage 126 is closed when these two parts are engaged and open when disengaged. Bushing 103 is positioned around valve poppet 106 snugly but not in a fluid tight manner, allowing valve poppet 106 to slide up and down and a fluid to slowly flow across bushing 103 . A bore within bushing 103 can be sized and/or dimensions of valve poppet 106 can be sized to allow a selected or predetermined amount of the working fluid to flow from chamber 105 , between bushing 103 and valve poppet 106 , and into chamber 104 . End portion 108 may be tapered to fit within valve seat 110 in a fluid-tight fashion.
[0026] Still referring to FIG. 3, cam disk 121 of valve 100 of this invention may have a simple round hole to accommodate axial element 122 so that cam disk 121 is stable only at one position, or cam disk 121 may have slot 124 within which axial element 122 is positioned to provide two stable positions. As shown in FIG. 3, valve 100 is in an assembled condition, a condition in which there is no working fluid in the valve cavity. In this position, spring 116 is slightly compressed and cam piston 118 is at its high position and spring piston 117 is at its low position, forcing pin 119 to engage valve poppet 106 and to push valve poppet 106 down to close valve outlet 111 . FIG. 3 shows valve 100 in a normally closed position. However, if spring 115 is of sufficient strength to exert a force strong enough to overcome the downward force from spring 116 , then valve outlet 111 can be open at this position. This is simply a design option, allowing valve 100 to be normally open or normally closed.
[0027] Referring to FIG. 4, the cam disk arrangement of valve 100 is illustrated in more detail. Cam housing 114 is attached to spring cylinder 112 , preferably by a threaded arrangement at one end. Cam housing 114 has center hole 128 to accommodate cam piston 118 , and slot 129 across the diameter at the other end accommodates cam disk 121 . Bolt 122 serves as a rotating axis for cam disk 121 . FIG. 4 shows cam piston 118 at its lowest position and spring 116 is compressed.
[0028] Referring to FIG. 5, when a pressurized fluid enters into valve 100 at a pressure P f , it flows into chamber 104 , between bushing 103 and valve poppet 106 and pushes pin 119 upward, thus allowing valve poppet 106 to move up and to open valve outlet 111 . Valve 100 is now at its open position and the fluid flows freely through the valve cavity. At this position, pin 119 is retracted fully by the fluid force and spring piston 117 is pushed up to compress spring 116 . Spring piston 117 may abut cam piston 118 if necessary. The technical requirements of compression of spring 116 depend on the spring involved, the fluid pressure, and the size of pin 119 . This is a stable position as cam disk 121 is at rest. Valve lever 123 can be positioned vertically or horizontally depending on the preference. To close valve 100 , lever 123 is rotated a quarter turn, or at a specified angle depending on the design of cam disk 121 .
[0029] Referring to FIG. 6, valve 100 is in a closed position when cam disk 121 is rotated to push cam piston 118 to its lowest position, thus compressing spring 116 , which exerts a force upon spring piston 117 and pin 119 . Pin 119 thus enters into chamber 104 , engages valve poppet 106 at the entrance of passage 126 , and pushes valve poppet 106 down to close outlet 111 . At this position, pin tip 120 closes passage 126 and end portion 108 closes outlet 111 . The fluid in chamber 104 exerts a full force on valve poppet 106 to close outlet 111 . The force required to close passage 126 with pin 119 is supplied by spring 116 , which travels a distance t, as shown in FIG. 6. To assure secured valve closure, the bias force of spring 116 must be adequate. Thus, the selected spring material must have a spring rate so that a compression distance t produces a force greater than the force exerted on pin 119 by pressurized fluid in chamber 104 . Once a suitable spring 116 is installed, the required compression distance t can be readily supplied by movement of a small cam disk and a relatively short lever. By having a suitable slot within cam disk 121 , pushing valve lever 123 from right to left, as shown in FIG. 6, will position cam disk 121 at a stable position and lock valve 100 in a closed position. With this invention, valve actuating pin 119 is not subjected to excessive forces that can cause damage. The pin assembly essentially floats between spring 116 and the fluid inside the valve cavity, unlike the rigid valve stems of conventional valves shown in FIG. 1. This invention allows an on-off valve to be actuated by forces generated from a human hand very quickly even at very high fluid pressures. There is no need to limit the flow rate as a relatively large valve outlet can be installed in a relatively small valve assembly.
[0030] Still referring to FIG. 6, to open valve 100 requires only lifting valve lever 123 to its vertical position shown in FIG. 3. Then the pressurized fluid in chamber 104 pushes pin 119 upward and flows through passage 126 to the outside of outlet 111 . Chamber 104 thus loses its pressure and the force holding down valve poppet 106 . Simultaneously, the fluid inside chamber 105 is still at full pressure and exerts a considerable force on end portion 108 in an upward direction. Therefore, valve poppet 106 will quickly move up, thus opening valve outlet 111 . The check valve arrangement 127 inside valve poppet 106 prevents the fluid from flowing back into chamber 104 , through passage 126 . The fluid travels around bushing 103 to reach chamber 104 , which takes more time because of the flow restrictions. This time delay allows valve poppet 106 to move up fully before it is balanced again in the fluid. Spring 115 assists this effort.
[0031] Still referring to FIG. 6, a close examination of valve 100 shows that it is a pilot-operated valve in which there is a pilot fluid circuit linking the two fluid chambers 104 and 105 . By manipulating the pressure inside the two chambers 104 and 105 , a force inbalance is created to move a relatively large valve poppet. The pilot circuit comprises central fluid passage 126 of valve poppet 106 , chamber 104 , the fluid passage around bushing 103 , and chamber 105 . Valve actuating pin 119 controls the pilot circuit flow in a prescribed direction. Valve poppet 106 should slide smoothly at all times. Thus bushing 103 is preferably made of a relatively soft bearing material and is smooth. Restricted fluid flow across bushing 103 is not preferred, particularly with incompressible fluid such as water at high pressures. It is possible to have a separate channel for flow from chamber 105 to chamber 104 .
[0032] Referring to FIG. 7, valve 200 represents another embodiment of this invention having a dedicated pilot fluid passage. Valve 200 is a manually operated on-off valve capable of high pressure operations. Valve 200 is similar to valve 100 , except that the valve poppet and the valve bushing are different. Valve 200 has a bushing assembly comprising bushings 203 and seal 230 . This assembly separates valve cavity 202 into upper chamber 204 and lower chamber 205 . The fluid does not flow from chamber 205 to chamber 204 through the bushing assembly. Instead, the fluid flows through a relatively small fluid passage 231 within valve poppet 206 , which can be parallel to central fluid passage 226 . Fluid passage 231 is long enough to always connect the two chambers 204 and 205 but it is comparatively smaller to allow chamber 104 to lose pressure momentarily when passage 226 is opened. With this arrangement, valve poppet 206 can be made with a relatively hard material while bushing 203 is made of a relatively softer material. Seal 230 prevents erosion of the soft bushings. Seal 230 can be made of common polymeric seal materials.
EXAMPLE
[0033] To better illustrate details of this invention, valve 300 was constructed according to the embodiment shown in FIG. 7 and illustrated in part in FIG. 8. Valve 300 had valve poppet 306 straddling bushing assembly 303 . Upper end 307 of valve poppet 306 was 0.312 inches in diameter and lower end 308 was 0.250 inches in diameter and mated with a tapered center hole of valve seat 310 . The contact circle or the sealing circle of valve seat 310 contacting end portion 308 was about 0.188 inches in diameter.
[0034] Valve poppet 306 had central fluid passage 326 of 0.050 inches in diameter and parallel side passage 331 of 0.020 inches in diameter. Valve actuating pin 319 was 0.078 inches in diameter and had tapered end 320 for engaging a slightly tapered entrance of passage 326 . The sealing circle around pin end 320 when engaged to valve poppet 306 was about 0.060 inches in diameter. When pin 319 engaged passage 326 , an annular cross-sectional surface area of about 0.0016 square inches of pin 319 was exposed to the fluid in chamber 304 . At the same time in chamber 305 , an annular cross-sectional surface area of about 0.0487 square inches of valve poppet 306 was exposed to the pressurized fluid.
[0035] Further, valve 300 had a 0.750 inch diameter die spring 316 inside spring cylinder 312 . Spring 316 had a spring rate of about 40 lb f per 0.1 -inch compression. The initial compression of spring 316 during assembling was 0.05 inches, corresponding to an initial valve closing force of 20 lb f on pin 319 . When water of 20,000 psi entered valve 300 , the water exerted a force of 0.0016×20,000=32 lb f on pin 319 . This force is greater than the 20 lb f from spring 316 . Thus pin 319 was lifted. Pin 319 was then exposed fully to the water and a force of 0.0048 square inches×20,000 psi=96 lb f worked on pin 319 and pushed pin 319 out to compress spring 316 . In the meantime, passage 326 was opened and water in chamber 304 quickly lost pressure as water flowed out through passage 326 , check valve arrangement 327 , and outlet 311 . Valve poppet 306 rapidly moved up until stopped by spring cylinder end 313 . The fluid force inside chamber 305 available for pushing up valve poppet 306 was estimated at 0.0487 square inches×20,000 psi=974 lb f . Thus, valve poppet 306 moved up very quickly. Further, once the sealing circle around the valve seat 310 was broken, the entire cross-sectional area of the valve poppet was exposed to 20,000 psi water. Therefore, the pushing force was increased to about 1,470 lb f . Check valve 327 inside valve poppet 306 prevented water from flowing back to upper chamber 304 through the larger central passage 326 . Once moved up, valve poppet 306 stayed up as the water pressure equalized at its two ends. Valve 300 was then in the open position. The seal 330 prevented valve poppet 306 from dropping down. Thus there was no need for another spring inside the valve cavity to move valve poppet 306 . In high-pressure applications, the valve cavity is relatively small because there may not be room for a relatively large spring around the valve poppet.
[0036] Still referring to FIG. 8, to close valve 300 required moving pin 319 back into chamber 304 . A spring force greater than 96 lb f was applied to the outside end. Spring 316 was initially compressed 0.05 inches to create a downward force of 20 lb f , which was subsequently canceled by the water force on pin 319 . A net water force of about 96−20=76 lb f pushed pin 319 against spring 316 , resulting in compression of about 0.19 inches. Thus, the total compression of spring 316 was 0.19+0.05=0.24 inches. The original overall length of spring 316 was 1.5 inches. The length of compressed spring 316 at the valve-open position was 1.5−0.24=1.26 inches.
[0037] The cam assembly of valve 300 was designed to provide a vertical travel of 0.3 inches on pin 319 . When the valve lever was rotated down, the cam piston moved down 0.3 inches, thus further compressing spring 319 . A spring force of about 120 lb f was generated by the 0.3 -inch compression, which was sufficient to overcome the water force of 76 lb f . Thus, valve poppet 306 moved down to close valve outlet 311 . Once seated, the water force working on pin 319 was reduced back to 32 lb f . Thus, spring 316 firmly maintained pin 319 down to close passage 326 . Valve poppet 306 was held down against valve seat 310 by the water force. The net valve closure force from the water was 1470−947=523 lb f , which was very substantial. Valve 300 thus stay closed. This setup of valve 300 accommodates water pressures up to about 25,000 psi. If water pressures greater than 25,000 psi are to be applied, then spring 316 must be changed. For example, a spring with a spring rate of 60 lb f per 0.10 -inch compression will allow valve 300 to be operated at water pressures up to 35,000 psi. The pressure capability of valve 300 can be increased by installing a cam disk assembly having a vertical travel greater than 0.3 inches.
[0038] It was clear that valve 300 can be designed with precision to construct on-off valves suitable for use at various pressure ranges. A very high outside force can be generated through the cam assembly to provide fast valve actuation. Yet, the force acting on the valve actuating pin is isolated and controlled to protect this pin. By virtue of a floating valve poppet, a relatively large valve outlet port is possible, without sacrificing valve performance. By using water force to open and close the valve outlet port, positive valve actuations are assured. Valve 300 had all the virtues desired in an on-off valve for use with incompressible fluids such as water at very high pressures.
[0039] [0039]FIG. 9 shows another embodiment of this invention, an improved spring-operated pressure relief valve ideally suited for use with incompressible fluids at high pressures. Valve 400 of this invention is very similar to valve 300 illustrated in FIG. 8, except that it does not have a valve actuating cam disk or lever. Instead, spring cylinder 412 has one end 413 inside valve body 401 and the other end engaged to threaded plug 414 that abuts cam piston 418 , which in turn abuts compression spring 416 . End plug 414 can be rotated with a screw driver or other suitable tools to compress or decompress spring 416 , thus changing the spring force exerted on valve actuating pin 419 . The spring force is set according to the fluid pressure inside the valve cavity.
[0040] In operation, a fluid such as water enters into valve 400 at a pressure P and flows into chambers 404 and 405 . The water exerts force on and pushes pin 419 out of chamber 404 , thus raising valve poppet 406 and opening outlet 411 . To set valve 400 , end plug 414 is moved into spring cylinder 412 to compress spring 416 until the spring force is increased to a level sufficient to move pin 419 back into chamber 404 and to push down on valve poppet 406 to close valve 400 . Valve 400 is now set for fluid pressure P. When the fluid pressure in the fluid system is increased beyond fluid pressure P, pin 419 will again disengage from valve poppet 406 , causing valve outlet 411 to open and fluid to be released. As a result, the fluid pressure inside valve 400 will drop and valve 400 will again close to repeat another cycle.
[0041] Comparing valve 400 of FIG. 9 of this invention to the conventional pressure relief valve illustrated in FIG. 2 will show one difference in the presence of the floating valve poppet. In conventional valves, the spring has to be very large and powerful to handle incompressible fluid such as water at high pressures and high flow rates. The powerful spring force is applied directly to the valve stem and to the valve seat. Therefore, there is very much pounding and erosion around the tip of the valve stem and valve seat. The valve will thus have a relatively short life. As a result, spring-operated automatic pressure relief valves are rarely used for water jetting applications above 10,000 psi. Instead, rupture disks are commonly employed at the crankshaft pumps, despite their unreliable performance.
[0042] Valve 400 of this invention can be reliably used at water pressures above 20,000 psi. By using a valve actuating pin of a moderate diameter, an ordinary die spring can be used to handle water at high pressures. The situation with valve 400 is very similar to that of valve 300 . For example, a 1.0 inch diameter die spring with a spring rate of 50 lb f per 0.1 -inch compression can be used in valve 400 to handle water at pressures up to 35,000 psi with good sensitivity. Such performance is possible with the design of this invention.
[0043] [0043]FIG. 10 shows yet another embodiment of this invention wherein a spring-operated on-off valve is normally closed and depends on a lever-aided force to open. Valve 500 of FIG. 10 is very similar to valve 300 and valve 400 , except that valve 500 is normally closed by a spring force and its opening depends on a force generated by a human hand or foot. Valve 500 has spring housing 521 attached to valve body 501 directly or indirectly in a fluid-tight manner. Spring housing 521 has cylindrical cavity 535 to accommodate spring piston 517 , compression spring 516 , and end plug 514 . Lever 523 is anchored at one end inside spring housing 521 by anchor bolt 522 through slot 536 in spring piston 517 . The other end of lever 523 extends outside of spring housing 521 . Lever 523 is free to rotate around anchor bolt 522 and the rotation generates a linear travel of spring piston 517 inside cavity 535 . Spring housing 521 is mounted on base 537 from which force is applied to lever 523 . Base 537 can be in the form of a handle to yield a hand-operated on-off valve that is normally closed, which requires a hand force to open. Base 537 can be in the form of a plate to yield a foot-operated on-off valve. Valve 500 is different from valve 200 , which is normally open. Spring piston 517 abuts valve actuating pin 519 that controls the pilot fluid circuit in a way similar to other valves of this invention. End plug 514 is used to adjust the initial compression of spring 516 required for closing valve outlet 511 at the fluid pressure P involved. When an outlet flow from valve 500 is needed, lever 523 is pulled or pressed toward base 537 . When the flow is not needed, lever 523 is released.
[0044] While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.
|
An on-off valve that operates between an open position and a closed position, particularly with high-pressure working fluids. The on-off valve has a valve body that defines a valve cavity. A valve poppet is slidably mounted within the valve cavity. A bushing is mounted with respect to the valve body and divides the valve cavity into a first chamber and a second chamber. One end of the valve poppet is positioned within the first chamber and an opposite end of the valve poppet is positioned within the second chamber. The valve body has an inlet and an outlet, which communicate with each other in the open position of the on-off valve. A spring urges the valve poppet into the first chamber. In the closed position of the on-off valve, the valve poppet closes the outlet. An actuating pin is slidably mounted with respect to the valve body. In the closed position, the actuating pin seals the passage of the valve poppet. An actuator is used to operate the actuating pin between the open position and the closed position of the on-off valve.
| 1
|
BACKGROUND OF THE INVENTION
The invention relates to gang form bolts for use in holding a tie rod passing through abutting frames of prefabricated panel units.
This invention is an improvement on and an adaptation of the gang form bolt of U.S. Pat. No. 3,756,555, issued to Doubleday et al on Sept. 4, 1973, as assigned to the assignee of the present invention, and hereby incorporated by reference.
The use of prefabricated panels in a gang of formed sections either preassembled or assembled on the job is well known in the concrete pouring art. Such prefabricated units usually have a flat base of plywood or other suitable material of appropriate dimensions reinforced by a metal frame extending around the periphery of each unit. The metal frame is usually of I-shaped cross sections and edges thereof which abutt when the panel units are in position. These edges are suitably cut away to provide space for insertion of tie rods to extend between spaced gang from section between which the concrete is to be poured. The tie rods prevent the weight of the concrete from forcing the gang form sections away from each other.
The prior art includes numerous tie rod holding bolts as shown in the following U.S. Patents:
______________________________________U.S. Pat. No. Issue Date______________________________________3,067,479 - Schimmel December 11, 19623,142,883 - Kort et al August 4, 19643,584,827 - Shoemaker June 15, 19713,655,162 - Shoemaker April 11, 19723,945,602 - Doubleday et al March 23, 19764,221,357 - Bowden et al September 9, 1980______________________________________
The Schimmel patent discloses a tie rod bolt including a form slot leg and a tie engaging leg. A notch disposed in between the form slot leg and the tie engaging leg is disposed adjacent the back of the frames.
The Kort et al patent discloses a tie rod and anchor bolt combination having a form slot leg and a tie rod engaging leg with two legs in between. The tie rod is curved to straddle the two legs between the slot leg and the rod engaging leg.
The two Shoemaker patents disclose Waler clamp assemblies for concrete wall forms, each assembly including a surface for abutting the back edges of the frames.
The Doubleday et al U.S. Pat. No. 3,756,555, incorporated by reference above, discloses a gang form bolt including a form slot leg, a tie engaging leg and a middle leg. The middle leg has a hold for accomodating a pin to hold the tie rod bolt in place. The form slot leg and the middle leg are in common horizontal plane. The tie rod holding bolt is arranged such that the load on the tie rod is transmitted to the frames by the form slot leg.
The Doubleday et al U.S. Pat. No. 3,945,602 discloses a U-shaped (in cross section) tie rod holding bolt including 2 back edges abutting the frames for load transmission.
The Bowden et al Patent discloses a tie rod assembly wherein the tie rod places a straight axial load on the tie rod holding bolt.
Although the above and other tie rod holding bolts have been generally useful, they are often subject to one or more of number of disadvantages. In particular, an increase in tension in the tie rod often has the tendency to tip the tie rod holding bolt or to bend the tie. Some prior art tie rod holding bolts have been under such tension that, when they are unloaded, the bolt has a tendency to snap off and act as a projectile which may be hazardous to personnel. Prior art designs which may at least partially overcome these problems are generally complex in construction, requiring more pieces than the basic tie rod, tie rod holding bolt and holding pin combination.
OBJECTS
Accordingly, it is a general object of the present invention to provide a new and improved gang form or tie rod holding bolt.
A further object of the present invention is to provide a gang form bolt which is extremely stable and quite resistant to tipping under heavy loads.
A further object of the present invention is to provide a gang form or tie rod holding bolt which is easily and safely unloaded without any likelihood of injuring personnel by acting as a projectile.
A still further object of the present invention is to provide a gang form or tie rod holding bolt which is relatively simple in construction.
SUMMARY OF THE INVENTION
These and other objects of the present invention which will become apparent as the description proceeds are realized by a device having at least a tie rod holding bolt for holding a tie rod passing through abutting frames of prefabricated panel units and the frames having mating slots. The tie rod holding bolt comprises a body portion, a slot leg extending from a first end of the body portion for entry through the mating slots, a tie rod engaging leg extending from a second end opposite the first end of the body portion, the tie rod engaging leg extending parallel to the slot leg and in the same direction as the slot leg, a middle leg extending from the body portion, spaced from and between the slot leg and the tie rod engaging leg and extending in the same direction as the slot leg and the tie rod engaging leg. The tie rod engaging leg lies in a horizontal plane and the slot leg and middle leg are both outside of the horizontal plane of the tie rod engaging leg and the middle leg and the slot leg are adapted to straddle a tie rod engaged to the tie rod engaging leg. The slot leg and middle leg are disposed in different horizontal planes and the slot leg and middle leg are disposed on opposite sides of the horizontal plane of the tie rod engaging leg. The tie rod engaging bolt is adapted for holding a tie rod having a straight portion and a loop portion with the loop portion around the tie rod engaging leg and with the straight portion disposed in the horizontal plane of the tie rod engaging leg. The slot leg includes a wedge pin accomodating hole. The tie rod holding bolt is adapted to avoid excessive eccentric load by accomodating a tie rod such that the tie rod will maintain a straight axial load on the tie rod holding bolt. The tie rod holding bolt is adapted to transfer loads to the abutting frames by the middle leg and the form slot leg is positioned on the body such that it will have a gap on the front sides of the mating slots.
The assembly of the present invention includes the gang form bolt in combination with a tie rod, two frames, and a wedge pin.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features of the present invention will be more easily understood when taken in conjunction with the detailed description and the accompanying drawings wherein like reference characters represent like parts throughout and in which:
FIG. 1 shows an exploded view in perspective of the tie rod holding bolt of the present invention and an associated tie rod and associated wedge pin.
FIG. 2 shows a top view of a tie rod bolt as mounted on abutting frames of prefabricated panel units.
FIG. 3 shows a side view of the installed tie rod holding bolt and associated structure shown in FIG. 2.
FIG. 4 shows a cross section view taken along lines 4--4 of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Considering now FIGS. 1, 2, 3, and 4, the tie rod holding bolt 10 according to the present invention will be discussed. FIG. 1 shows an exploded view in perspective of the tie rod holding bolt 10 of the present invention in combination with a tie rod 30 and a wedge pin 40 with phantom lines indicating the installed position of tie rod 30. FIG. 2 shows a top view of the tie rod holding or gang form bolt 10 of the present invention in combination with the tie rod 30, wedge pin 40, abutting frames 50A and 50B, and adjacent panel sections 52A and 52B. FIG. 3 shows a side view of the same assembly as shown in FIG. 2 except that panel sections 52A and 52B are not shown, whereas FIG. 4 shows a cross section view along lines 4--4 of FIG. 3.
The tie rod holding bolt 10 of the present invention includes a body portion 12 shaped as shown and having a raised corrugation 12C for strength, a form slot leg 14 disposed at the front of the body portion 12, a tie rod engaging leg 18 disposed at the back of the body portion 12, and a middle leg 16 disposed in between the form slot leg 14 and the tie rod engaging leg 18.
The tie rod 30 includes a looped portion 30L and a straight portion 30S, the looped portion 30L being shaped and sized to fit around the tie rod engaging leg 18 with the straight portion 30S disposed in a horizontal plane of the tie rod engaging leg 18. In addition to the straight portion 30S of the tie rod 30 being disposed in the plane of the tie rod engaging leg 18, the slot leg 14 and the middle leg 16 are both outside of the substantially horizontal plane (i.e., within 15 degrees of horizontal) of the tie rod engaging leg 18 and the middle leg 16 and slot leg 14 are adapted to straddle the tie rod 30 engaged to the tie rod engaging leg 18. This feature is best shown in FIG. 3. Further, the slot leg 14 and the middle leg 16 are disposed in different substantially horizontal planes on opposite sides of the substantially horizontal plane of the tie rod engaging leg 18. The substantially horizontal planes will preferably be horizontal. As used herein, "horizontal" or "substantially horizontal" refers to the parts of the holding bolt 10 when it is installed. For example, to say that tie rod engaging leg 18 is in a horizontal plane means that in its installed orientation leg 18 will be in a horizontal plane.
The slot leg 14 includes a wedge pin accomodating hole 14H such that wedge pin 40 may be mounted therein. A stop portion 14S prevents leg 14 from being pushed too far into mating slots 54A and 54B. Quite importantly, the tie rod holding bolt 10 is shaped with relative distances between the form slot leg 14, middle leg 16, and tie rod engaging leg 18 such that there will be a gap between the form slot leg 14 and the front of the mating slots 54A and 54B on the abutting frames 50A and 50B. Instead of form slot leg 14 contacting the front (i.e., that portion closest to panel sections 52A and 52B) of the mating slots 54A and 54B, the front edge 16L of middle leg 16 will be in contact with the back of the two abutting frames 50A and 50B.
OPERATION
The use of the present invention will be readily appreciated by those of ordinary skill in the art, but will be briefly reviewed herein. The assembly of the present invention may be assembled by sliding the tie rod holding bolt 10 into the two abutting frames 50A and 50B with the tie rod 30 already in place extending through slot 50C at the back of frames 50A and 50B and a similar slot at the front of frames 50A and 50B. The form slot leg 14 will slide through the mating slots 54A and 54B and the tie rod engaging leg 18 will slide into the loop 30L. The load or front edge 16L of middle leg 16 will be disposed adjacent the back of the abutting frames 50A and 50B. The frames 50A and 50B would be bolted together (bolts not shown) in a manner well known in the art. The wedge pin 40 may be inserted into the wedge pin accomodating hole 14H to lock the tie rod holding bolt 10 in place.
The operation of the present gang form or tie rod holding bolt of the present invention under a tension load will presently be discussed. In particular, the legs 14, 16 and 18 of the gang form bolt 10 are arranged so that the tie rod straight portion 30S will remain straight under a tension load. The form slot leg 14 which passes through the mating slots 54A and 54B of the form and the middle leg 16 which rests against (i.e., abuts) the back edge of the form or frame members 50A and and 50B are offset so that the center line of the tie rod 30 is midway between these two legs. In addition to this, the tie rod engaging leg 18 which holds the tie rod loop 30L is in alignment with the center line of the tie rod 30. Any tendency of the bolt to tilt is resisted by the tension on the tie which works against an eccentric load on the bolt.
On various earlier designs of bolts, a tilt movement of the bolt released tension on the tie which in turn transferred an eccentric load onto the bolt. Since this tie, as any other tension member, will always resist bending when under load, the straddling of the tie rod 30 by the slot leg 14 and the middle leg 16 resists possible tipping of the gang form or tie rod holding bolt 10. The concept is somewhat similar to a post tension beam. The offset design of the gang form bolt legs 14 and 16 straddle the tie, thereby stabilizing the bolt 10 by the tension load which causes the tie rod 30 to remain straight. As tension in the tie rod 30 increases, the force required to bend the tie rod is increased. Therefore, the bolt 10 is prevented from tipping by tie tension.
Another important feature of the present invention is that the load of the bolt 10 is transferred to the back edge of the form by the middle leg 16 of the gang form bolt 10. The front of the slot leg 12 does not transfer the load to the front of the mating slots. This placement of the load at the middle leg 16 has at least two advantages over some earlier designs which transferred the load to the edge of the form slot by the leading edge of the form slot leg. First, by utilizing the middle leg instead of the form slot leg to transfer the load to the back of the form, the distance between the pivot point and the tie loop leg is shortened which reduces the angle of tipping. Thus reduces the eccentric load on the bolt which would cause premature failure. Second, since the middle leg is shorter than the form slot leg, the distance of travel and the amount of frictional resistance at the load bearing point is reduced. This allows the bolt to be unloaded with the blow of a hammer without completely disengaging the form slot leg, reducing the tendency of the bolt to act as a projectile which could be hazardous to personnel and difficult to recover.
The present design is further advantageous in that having the load bearing point or edge 16L on the back of the form by the middle leg and the arrangement of the form slot leg and middle leg straddling the tie creates a stabilizing condition so that:
Any tendency of the bolt to tip downward which would cause a bending of the tie rod would be resisted by tie rod tension.
Any tendency of the bolt to tip upward which would pull the middle leg away from the form and bend the tie rod about the form slot leg would be controlled by the length of the tie rod and resisted by the tension load on the tie rod.
The double offset of this design allows the tension placed on the tie to resist the aforementioned tipping. Thus, the design of the gang form bolt prevents tipping by this leg arrangement (i.e., form slot leg above tie, middle leg below tie, and tie rod engaging leg at center of tie) which could result in an eccentric load on the bolt and casue a bending failure. An increasing load on the tie rod will tend to keep the tie rod and bolt in alignment, in contrast to some prior art designs wherein an increasing load could cause the bolt to rotate which would develop an eccentric load possibly leading to fold-over failure of the bolt.
The tie holding bolt 10 according to the present invention may be made of metal, steel, or other stress resistant materials commonly used for tie rod bolts.
Although various details have been disclosed herein, it is to be understood that these details are to be for illustrative purposes only. Various modifications adaptations of the present invention will be readily apparent to those of ordinary skill in the art. Accordingly, the scope of the present invention should be determined by reference to the appended claims.
|
A gang form or tie rod holding bolt is adapted for holding a tie rod passing through abutting frames of prefabricated panel units, the frames having mating slots. The tie rod holding bolt includes a body portion and a slot leg for extending through the mating slots, a middle leg for loading the frames, and a tie rod engaging leg for transferring a load from the tie rod to the holding bolt. The form slot leg and the middle leg are horizontally offset to straddle the tie rod and the middle leg is adapted to transfer the load to the frames, thereby providing the bolt with great stability under heavy loads. The design avoids eccentric load on the bolt. An assembly includes the bolt, tie rod, wedge pin and two frames.
| 4
|
BACKGROUND OF THE INVENTION
This invention relates, in general, to a method for plasma etching organic materials and, more specifically, to a method for anisotropically etching organic materials in a hydrogen plasma.
The increasing complexity of semiconductor devices has required technological changes in the areas of materials, lithography, and processing. One such required change is the need for an anisotropic etch process for organic films. Two organic films which are now commonly used in semiconductor processing and which, in some applications, require anisotropic etching are, for example, polyimides and photoresist.
Polyimide is an organic material of increasing importance in semiconductor device processing because it possesses desirable dielectric and passivation properties. Current wet chemical as well as high pressure plasma etch processes for polyimide, however, produce lateral etching which, at best, is proportional to the vertical etch depth. The trend in semiconductor devices is towards smaller and smaller device geometries with closely spaced components and fine pattern sizes. As the device geometries continue to shrink, so also do the required openings which must be cut through the polyimide layers. The necessity for small closely spaced openings through polyimide layers requires an anisotropic polyimide etch process.
Two new process technologies which are becoming important are reactive ion etching and ion milling. Both of these processes require thick organic masking layers to pattern an etchable material because resist attack is so severe with these etch processes that it may be the limiting factor in determining the success or failure of the etch process. In addition, a thick resist is required in the process both for good step coverage and to minimize standing wave patterns caused by interference from reflected light. The need for thick resist layers is seemingly incompatible with high resolution and close dimensional control from a lithographic standpoint since the latter are usually best obtained in thin resist layers, typically less than 400 nanometers. One way to pattern the thick organic masking layer and to simultaneously maintain high resolution and dimensional control is to use a trilevel process. In that process a thick organic film of photoresist or polyimide is first applied to the substrate. The thick organic film will provide the ultimate masking layer and additionally serves to planarize the underlying substrate. Over the thick organic layer is applied an inorganic intermediate masking layer (a "hard" mask) and then a thin top layer of x-ray or e-beam photoresist. In using the trilevel process the top layer of photoresist is patterned in a desired fine geometry pattern. This in turn is used as an etch mask to pattern the hard mask. The hard mask is then used as an etch mask to pattern the thick organic layer. Etching the thick organic layer requires an anisotropic etch to replicate the pattern provided by the hard mask.
There are a number of ways to etch organic materials. It is well-known, for example, that organic films can be etched in an oxygen plasma; oxygen plasma etching or "ashing" of photoresist is common in the microelectronic industry. Ashing of a masked organic layer in an oxygen plasma, however, is an isotropic process resulting in severe undercutting of the mask material. Likewise, liquid etchants etch organic layers isotropically.
Reactive ion milling is known to be an anisotropic process with operating pressures on the order of 1.3×10 -2 Pa. The low pressure results in a longer mean free path and better ion directionality which achieve the anisotropy. Under such conditions organic layers can be etched anisotropically with little undercutting of the mask layer. In many applications of ion milling, however, severe attack of the mask material makes good line width control difficult. In addition, reactive ion milling is characterized by very low throughput and high system cost because of the low vacuums required.
In view of the need for a process for anisotropically etching organic films and further in view of the difficulties associated with present anisotropic etching methods, a need existed for an improved anisotropic etch process.
It is therefore an object of this invention to provide an improved method for anisotropically etching organic films.
It is another object of this invention to provide an improved method for etching organic films without high vacuum equipment.
It is a further object of this invention to provide an improved method for etching openings of predetermined sidewall contour through a layer of organic material.
It is yet another object of this invention to provide an improved method to etch openings in an organic layer without undercutting the etch mask.
BRIEF SUMMARY OF THE INVENTION
The foregoing and other objects and advantages are achieved in accordance with the invention through the use of a hydrogen plasma etch technique. A layer of organic material to be etched is provided on a suitable substrate and a patterned mask having the desired etch pattern is provided over the organic material surface. The substrate with the organic layer and mask thereon is placed in a plasma reactor and positioned substantially parallel to and electrically coupled with a cathode electrode within the reactor. The organic layer is maintained at a temperature below that which will cause the patterned mask to flow. The pressure in the reactor is reduced and then maintained at a pressure below about 53 Pa. A plasma is generated within the reactor with the plasma species including hydrogen and not more than a small amount of oxygen. The portion of the organic layer exposed through the etch mask is anisotropically etched by reacting the hydrogen plasma species with the organic material. After a predetermined amount of the organic layer is removed, plasma etching is terminated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a semiconductor structure including an organic layer;
FIG. 2 illustrates the effect of etching an organic layer with an isotropic etchant;
FIG. 3 illustrates anisotropic etching of an organic layer in accordance with the invention;
FIG. 4 illustrates plasma reactor apparatus for carrying out the invention;
FIG. 5 illustrates etch rate as a function of pressure in hydrogen and oxygen plasmas;
FIG. 6 illustrates etch rate as a function of temperature in hydrogen and oxygen plasmas;
FIG. 7 illustrates etch rate of photoresist in a hydrogen plasma as a function of RF power;
FIG. 8 illustrates etch rate of polyimide in a hydrogen-nitrogen plasma as a function of nitrogen percentage; and
FIG. 9 illustrates results of etching an organic layer in a two-step process in accordance with the invention to achieve openings in the layer having a predetermined sidewall contour.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates a typical structure encountered in the semiconductor technology. Overlying a substrate 20 is an organic layer 22. It is necessary, in the fabrication of some desired structures, to etch the organic layer in some predetermined pattern. A masking layer 24, normally an inorganic material, is provided over the organic layer in order to obtain the desired pattern. The openings 26 in mask layer 24 illustrate a pattern that it is desired to replicate in the underlying organic layer 22.
FIG. 2 illustrates the undercutting of mask layer 24 which results when layer 22 is isotropically etched, for example, in a high pressure plasma or wet etchant. Instead of etching through the organic layer 22 and replicating the openings 26 in mask layer 24 as indicated by the dotted lines 28, the conventional isotropic etchants also etch horizontally undercutting the mask as the vertical etching proceeds through the organic material. As a result the openings etched in the organic layer do not have vertical sides replicating the mask openings, but instead have tapered sidewalls as indicated at 30. The width of the resultant opening is also difficult to control in such a process and often is greater than the mask opening.
FIG. 3 illustrates the result of anisotropically etching organic layer 22 in accordance with the invention. A patterned etch mask 24 overlies an organic layer 22 which is provided on a substrate 20. Openings 26 in the etch mask are replicated in the underlying organic layer. Etching the organic layer, in accordance with the invention, in a hydrogen plasma at a pressure between about 13.3 Pa and about 53 Pa results in nearly vertical sidewalls 32. Additionally, the width 34 of the opening in the etch mask is replicated by the width 36 of the opening in the organic layer. The amount of undercutting, that is, the amount by which width 36 exceeds width 34 is minimal.
FIG. 4 illustrates a plasma reactor apparatus 38 in which the process in accordance with the invention is carried out. Reactor 38 includes a reaction volume 39 which is bounded, in this embodiment, by a base plate 40 and a bell jar 42. Within the reaction volume is a substantially planar RF plasma cathode 44 upon which substrates 46 can be placed. A quartz plate 48 separates the cathode from an anode 50 and limits the plasma discharge to the upper surface of the cathode. The cathode is powered by an RF generator 52; the anode is held at RF ground. An input 54 and exhaust 56 allow the injection of reactants and the removal of reaction products, respectively. For purposes of practicing the invention, it is necessary only that the cathode be located within the reaction volume, that the substrates to be etched be placed substantially parallel to that cathode, and that the substrates be electrically coupled, e.g., capacitively coupled, to the RF cathode. The substrates do not have to physically contact the cathode, although it may be convenient to do so. The reactor apparatus can otherwise have a variety of different configurations without influencing the anisotropic etching process.
The following are non-limiting examples which further serve to illustrate the invention and to point out the best modes contemplated by the inventor.
EXAMPLE I
Samples are prepared by growing about 1.0 micrometer of thermal oxide on a polished silicon substrate. A thick organic film is formed over the thermal oxide on one side of the substrate. Organic films are formed having thicknesses ranging from about 0.5 micrometer to about 3.0 micrometer with a typical thickness of about 1.5 micrometer. The organic films include polyimides such as PI 2545 made by DuPont and conventional photoresists such as HR-100 and HPR-206 made by the Hunt Chemical Company. Over the organic layer is deposited a hard mask layer of either plasma deposited silicon nitride or plasma deposited silicon oxide having a thickness of about 120-150 nanometer. Finally, a layer of e-beam resist is deposited on the surface of the hard mask. The e-beam resist is patterned using e-beam lithography and then is used as an etch mask to reactive ion etch the hard mask layer using CF 4 or CHF 3 to etch the nitride or oxide, respectively.
Masked organic layers as prepared above are plasma etched at pressures ranging from about 13 Pa to about 66.5 Pa to measure etch rate and anisotropy or degree of undercutting. The lower pressure limit is selected because that pressure is one readily obtainable in conventional plasma reactor equipment without sophisticated and expensive vacuum pumping equipment. Still lower pressures are difficult to obtain and involve typical problems of high vacuum systems including more complex pumping equipment, greater expense, and lowered throughput. Samples are etched in both a pure hydrogen and in a pure oxygen plasma at 150 watts RF total power or 0.34 watts/cm 2 . Substrates are at room temperature and are heated above room temperature only by the heat produced in the plasma reaction.
FIG. 5 illustrates the measured etch rate found as a function of pressure. The etch rate in the hydrogen plasma is essentially independent of pressure over the range investigated. In contrast, the oxygen etch rate is highly pressure dependent with the etch rate increasing rapidly as the pressure is lowered.
There are two possible explanations for the oxygen plasma etch rate dependence on pressure. First, the increasing organic film etch rate as pressure is lowered suggests that ion bombardment aids the oxidation process. Since the energy of the bombarding ions increases as pressure decreases, the etch rate increases as pressure is lowered. Alternatively, the etch rate dependence may be a function of residence time effects. In the reactor used in this Example, the average residence time of plasma species in the discharge increased as the pressure decreased. An increase in residence time allows a more complete reaction of the plasma species with the organic material resulting in an increased etch rate.
Because the etch rate of the organic film in the hydrogen plasma changes little with pressure, the hydrogen plasma etch mechanism in this pressure regime is apparently quite different than the etch mechanism for the oxygen plasma. It appears that ion bombardment and residence time effects on etch rate are minimal in the hydrogen plasma process.
In etching through the organic film layer to the underlying silicon dioxide, each sample is given a 10% overetch, consistent with usual semiconductor processing practice. Each sample is examined using a scanning electron microscope (SEM) to determine the amount of undercutting that has occurred. With the oxygen plasma a significant amount of undercutting occurs at all pressures investigated with a slight increase in undercutting as the pressure is increased. In contrast, no undercutting is observed for samples etched in the hydrogen plasma for pressures less than or equal to about 53 Pa. Only at pressures greater than about 53 Pa is significant undercutting observed.
It is believed that both oxygen and hydrogen plasmas have two "modes" of etching. One mode is chemical in nature, and this mode dominates at high pressures and results in some horizontal etching or undercutting of the etch mask. The second mode, which is more physical in nature, is controlled by ion bombardment. This ion assisted mode dominates at low pressures and results in anisotropic etching. The transition from the chemical to the physical mode occurs at different pressures for hydrogen and oxygen plasmas. The transition pressure for oxygen lies somewhere between the 13 Pa investigated above and about 1.3×10 -2 Pa at which reactive ion milling is practiced. The transition pressure for hydrogen plasma is higher, about 50 Pa. Below the transition pressure purely anisotropic processes dominate. Above the transition pressure, isotropic components appear and dominate as the pressure is further increased. Anisotropic etching in a hydrogen plasma can therefore be practiced without expensive vacuum equipment at pressures between about 13 Pa and about 53 Pa.
EXAMPLE II
Polyimide samples are prepared as in Example I. These samples are etched in either an oxygen plasma or in a hydrogen plasma at a pressure of about 20 Pa at 150 watts RF power (0.34 watts/cm 2 ). The temperature of the substrates in the reactor is varied from about room temperature to about 130° C. FIG. 6 illustrates how the etch rate of the organic layer in both oxygen and hydrogen plasmas varies as the temperature changes. The etch rate in the hydrogen plasma changes very little as the temperature increases. In contrast, the etch rate in the oxygen plasma increases rapidly with temperature. Arrhenious plots of the data for both hydrogen and oxygen plasma etching suggest different etch mechanisms for the two plasma systems in this temperature range. The samples etched in the oxygen plasma show significant undercutting. The samples etched in the hydrogen plasma showed no substantial undercutting throughout the temperature range investigated. Previous experiments, such as those disclosed in U.S. Pat. No. 4,201,579 indicate that when etching isotropically in a barrel type plasma reactor the etch rate of organic materials in a hydrogen plasma increases dramatically if the temperature is raised above about 150° C. In those experiments, however, the intent was to completely remove the layer of organic material. In accordance with the present invention, in which an organic layer is anisotropically etched to provide a well-defined pattern in a residual portion of the organic layer, the temperature must be limited to about 130° C. to avoid flowing of the top level resist.
EXAMPLE III
Samples are prepared as in Example I. The samples are etched in a hydrogen plasma at about 20 Pa at room temperature. For different samples the RF power is varied up to about 0.68 watts/cm 2 . Representative data for one set of samples in which the organic layer is HR-100 photoresist are shown in FIG. 7. Similar etch rate characteristics are found for HR-100, polyimide and positive resists. The increasing etch rate is believed to be the result of increased reactive species production and/or enhanced ion bombardment energy.
EXAMPLE IV
Samples are again prepared as in Example I. In an attempt to increase the etch rate of the organic material without adversely affecting the anisotropy, oxygen is added to the hydrogen plasma. The etch rate of the organic material is found to increase approximately linearly with oxygen concentration in the hydrogen plasma. Substantial undercutting, however, is noted when the oxygen content of the mixed hydrogen-oxygen plasma exceeds about 8%. For oxygen content less than about 8% no substantial undercutting is noted. It appears that the mixed hydrogen-oxygen plasmas show an additive result. The purely chemical oxygen etch mode is superimposed on the ion assisted hydrogen etch mode. The result is some horizontal etching combined with vertical etching with the exact amount of horizontal etching being controlled by the oxygen percentage.
EXAMPLE V
Samples are prepared as in Example I. The samples are etched in a mixed hydrogen-nitrogen plasma. FIG. 8 illustrates etch rate results obtained when polyimide layers are etched in the mixed plasma at a pressure of about 20 Pa at 0.45 watts/cm 2 RF power. The etch rate of the polyimide layer increases with nitrogen percentage in the mixed plasma to about 40% nitrogen and then decreases with further additions of nitrogen. The samples are anisotropically etched without substantial undercutting.
The etch rate in the mixed hydrogen-nitrogen plasma is higher than the etch rate in either hydrogen or nitrogen alone. No substantial amount of undercutting is observed for any mixture of hydrogen and nitrogen under these conditions. With hydrogen alone, the dominating reaction is proposed to be:
C+2H.sub.2 →CH.sub.4
which forms methane as the principal product. In nitrogen alone the dominant product is believed to be cyanogen by the reaction:
2C+N.sub.2 →(CN).sub.2
In addition to methane and cyanogen, a third product, hydrogen cyanide may be produced when both hydrogen and nitrogen are present. It is the possible presence of the hydrogen cyanide which may explain the higher etch rate in the mixed hydrogen-nitrogen plasma than in either of the pure plasmas.
The enhanced etch rate without undercutting indicates that both hydrogen and nitrogen plasma etch by an ion assisted etch mechanism under these conditions.
EXAMPLE VI
Samples are prepared as in Example I. The organic layer is plasma etched in a mixture of hydrogen and argon. The argon addition does little to increase the etch rate of the organic material. The argon appears to act only as a diluant of the hydrogen plasma; apparently the purely physical ion bombardment by argon species is unimportant at these powers and pressures.
EXAMPLE VII
In certain applications it is desirable to be able to etch an opening through a thick organic film in such manner that the sidewall openings have a predetermined taper. One such instance, for example, is when a subsequent metallization layer must be deposited over a polyimide layer and make contact through an opening to an underlying material. Tapered openings in the polyimide aid in assuring good step coverage as the metal passes from the top of the polyimide to the underlying material.
Samples are prepared as in Example I. A two-step process is then used to produce an opening having tapered walls and controlled size in the thick organic layer. In the first step the organic layer is isotropically etched in an oxygen plasma through the first portion of the thickness of the organic film. In the second step the substrates are etched in a low pressure hydrogen containing plasma as in Example V to etch through the remainder of the organic film. The first step in the etching is an isotropic etch which produces undercutting of the hard mask. The second step is an anisotropic ion assisted etch which causes the lower portion of the opening to be the same size as the opening in the hard mask. FIG. 9 illustrates the result of etching a polyimide film 60 of about 2.2 micrometers thickness by the two-step etch process. The first about 0.8 micrometers of the film are isotropically etched in step one resulting in an undercut, sloped edge 62. The remainder of the film thickness is etched anisotropically in step two to yield a straight walled portion 64. The amount of tapering is controlled by the percentages of film thickness etched in each of the two etch steps. After etching, the hard mask 66 is removed to expose the patterned organic layer.
In the foregoing examples substrates were generally placed on the cathode within the plasma reactor apparatus. It is not necessary, however, that the substrates actually contact the cathode physically; the wafers must be electrically coupled to the cathode. It is believed that ion assisted etching takes place by hydrogen species which arrive at the cathode approximately normal to the cathode surface. To take advantage of this ion assisted etching and to achieve anisotropic etching the substrates are placed substantially parallel to the cathode surface.
Thus it is apparent that there has been provided, in accordance with the invention, an anisotropic etching process which fully meets the objects and advantages set forth above. While the invention has been described with respect to specific embodiments thereof, it is not intended that the invention be so limited. Those skilled in the art, after review of the foregoing description, will realize that certain variations and modifications are possible while still realizing the full benefit of the invention. These include, for example, variations in the structure to be etched, and modifications to the reactor apparatus. Other materials which do not have a volatile hydride and thus exhibit etch selectivity over the organic layer can be used as a hard mask. It is intended that all such variations and modifications be included within the scope of the appended claims.
|
A method is provided for anisotropically etching organic material to reduce mask undercutting. The layer of organic material to be patterned, with an overlying patterning mask is provided on a substrate. The substrate with the layer of organic material on it is placed on the powered electrode within a plasma reactor. A hydrogen plasma is generated in the reactor at a pressure between about 13.3 Pa and about 53 Pa. The organic layer which is not protected by the etch mask is etched by the hydrogen plasma. At these pressures the organic layer is removed by a process of ion assisted etching in which the hydrogen plasma chemically reacts with the organic material and the reaction is enhanced by ionic bombardment of the plasma species. Because the substrate and the organic material are placed on the powered electrode, the plasma ions impact the surface of the organic layer in a direction substantially perpendicular to the surface of the layer thus providing anisotropy to the etch.
| 7
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of application Ser. No. 10/617,134, filed Jul. 11, 2003, which claims benefit of U.S. Provisional application No. 60/394,871, filed on Jul. 11, 2002 (all of which is hereby incorporated by reference).
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a light ignitable, energetic materials. More specifically, the invention relates to light ignitable, energetic materials containing carbon nanotubes or activated carbon containing a metal.
[0004] 2. Discussion of the Prior Art
[0005] A carbon nanotube (CNT) is a hollow nanostructure consisting essentially of a graphitic plane rolled into a thin tube, both ends of which can be closed by a fullerene-type dome structure. The existence of CNT's was originally discovered by S. Iijima [see Nature 354, 56 (1991)]. The material exhibits various interesting mechanical and electrical properties. There exists two forms of carbon nanotubes, namely single walled nanotubes (SWNT) and multiwalled nanotubes (MWNT).
[0006] It has recently been reported by P. M. Ajayan et al in Science, Vol. 296, 705 (2002) that carbon nanotubes release a large photoacoustic effect when sujected to a flash of light caused by the absorption of the light. It seems that the phenomenon is predominantly present in SWNT's and that the temperature of the process can reach 1500° C. The inventors have also determined that activated carbon containing a metal such as palladium also possesses the property of releasing a photoacoustic effect when subjected to a flash of light.
GENERAL DESCRIPTION OF THE INVENTION
[0007] The object of the present invention is to exploit the above described property of carbon nanotubes and activated carbon containing a metal to produce a light ignitable, energetic material.
[0008] Accordingly, the present invention relates to a light ignitable, energetic composition comprising an intimate mixture of an energetic material and one of carbon nanotubes and activated carbon containing a metal selected from the group consisting of palladium, iron, nickel, cobalt, aluminum, copper, zinc, potassium, sodium and titanium.
[0009] The invention also relates to a method of preparing a light ignitable, energetic composition comprising intimately mixing an energetic material and one of carbon nanotubes and activated carbon containing a metal selected from the group consisting of palladium, iron, nickel, cobalt, aluminum, copper, zinc, potassium, sodium and titanium.
[0010] A variety of energetic materials can be used in the method of the present invention. Such energetic materials include black powder, ammonium perchlorate (AP), hexogen (RDX), octogen (HMX), pentaerythritol tetranitrate, (PETN), trinitrotoluene (TNT), nitroglycerine, nitrocellulose, ammonium nitrate, lead azide, lead styphnate, nitro plasticizers and picric acid. While the carbon nanotubes can be SWNT or MWNT, the single walled nanotubes are preferred.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] In general terms, the invention takes advantage of the photoacoustic effect of carbon nanotubes when subjected to a burst of light, e.g. a camera flash to ignite an energetic material. In order to test the theory, different carbon nanotubes were used, the most common one being a SWNT commercial available from Carbon Nanotechnologies, Inc., Houston, Tex. Different percentages of carbon nanotubes (1-90 weight percent) were manually mixed (gently) with black powder. Initially, the most efficient composition contained 5 weight percent SWNT mixed with 95 weight percent Grade 7 black powder. The composition exploded instantaneously after being subjected to a camera flash. It was found that black powder with the smallest particle size was the most effective. The same effect was observed when activated carbon containing a metal, e.g. palladium was mixed with black powder, and the resulting mixture was exposed to a camera flash.
[0012] The invention will be better understood from the following examples.
EXAMPLE 1
[0013] 3 weight percent of crude carbon nanotubes were mixed with 97 weight percent ground ammonium perchlorate. The mixture was homogenized using ball milling equipment for 15 minutes. The balls used in the mill were made of glass. The resulting composition was then exposed to an intense flash using a commercially available Vivitar (trademark) flash. The power of the flash was 200 W/cm 2 at a distance of 4.5 cm.
EXAMPLE 2
[0014] The procedure of Example 1 was repeated using 3%, 5%, 10% and 20% carbon nanotubes. At a concentration in excess of 20% nanotubes, the ignition phenomenon was less efficient, i.e. the combustion process (explosion) appears to be incomplete.
EXAMPLE 3
[0015] Energetic formulations containing carbon nanotubes and RDX, TNT, black powder or AP were ignited at distances from 3 to 7 cm using the Vivitar flash. In a few cases, ignition was possible from a distance as great as 14 cm.
EXAMPLE 4
[0016] The method of Example 1 was repeated using 5 weight percent activated carbon containing palladium (97% carbon and 3% palladium) with 95 weight percent ground ammonium perchlorate. The mixture was homogenized using the same ball milling equipment as in Example 1. The composition was ignited using a flash; however, the process was less efficient than when using carbon nanotubes.
EXAMPLE 5
[0017] The ignition effect was observed for a variety of mixtures of activated carbon containing 3-30% palladium catalyst and a variety of energetic materials. The ignition effect was similar to that observed when using carbon nanotubes, but seemed to be less efficient after 3 to 5 days. It is believed that the activated carbon was absorbing water which reduced the efficiency of the ignition phenomenon.
[0018] Compositions in accordance with the present invention can be used for light ignited pyrotechnic effects and as light ignited triggers for detonators, gas generators and air bags.
[0019] Various modifications may be made to the described embodiments without departing from the spirit and scope of the invention as defined in the appended claims.
|
Carbon nanotubes and activated carbon containing a metal such as palladium release a photoacoustic effect when subjected to a flash of light. A light ignitable, energetic composition is produced by mixing one of them with an energetic material such as black powder or ammonium perchlorate.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional patent application No. 61/065,591 filed on date Feb. 13, 2008, “A System and Method For Cryptographic Communications Using Permutation”.
FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
SEQUENCE LISTING OR PROGRAM
[0003] Not Applicable
US PATENT REFERENCES
[0004] 1. U.S. Pat. No. 4,405,829 September 1983, Rivest, Ronald L. et al, Cryptographic communications system and method
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The present invention relates to a cryptographic communications system and method.
[0007] 2. Description of the Related Art
[0008] Data privacy and security have been increasingly important in generation, exchange and storage of information. Data transmitted over communications channels are susceptible to interception, eavesdropping and modification. Computer networks and internet can be monitored, accessed without permission. Due to various reasons, data storage devices may be accessed undesirably. Therefore, a cryptographic communications system and method is undoubtedly required to protect information confidentiality.
[0009] There have been a plurality of encryption algorithms to protect information security. These encryption algorithms involve extensive arithmetic operations and bit/symbol substitution, therefore, require substantial computing power. Some sophisticated approaches even require dedicated hardware acceleration to achieve targeted performance. Fundamentally, the daunting computing cost is due to the fact that all current transformations and mathematical operations are performed at symbol/bit level to prevent bit/symbol level security breaches.
[0010] However, in a plurality of secure communications applications, symbol/bit level data security may not be required. For instance, in on-line software release, a binary executable is a bit sequence of 1s and 0s. Current encryption algorithms would encode the binary executable at bit level, which would be time consuming.
[0011] Nonetheless, encoding binary executables at bit sequence level can achieve data security at lower computational cost. For example, a 64-kilo-byte binary executable can be first partitioned into 64 1-kilo-byte bit sequences. Then these 64 1-kilo-byte bit sequences can be permutated to generate an encoded form of the binary executable ready for on-line software release.
[0012] In this example of encoding 64-kilo-byte binary executable at 1-kilo-byte bit sequence level, the permutation information can be defined as a secret key for this encryption. There are factorial 64! possible permutations, more complex than exponential complexity. Thus, without knowing the secret key, it is computationally infeasible to restore the order of the re-ordered 64 1-kilo-byte bit sequences and obtain the original binary executable using current computing technologies.
[0013] Furthermore, symbol sequence level permutation operates at symbol sequence level, therefore, may significantly improve encryption and decryption efficiency compared to symbol/bit level cryptographic manipulations.
[0014] Since symbol sequence level permutation encodes and decodes messages using the same secret key, it is a symmetric encryption approach.
[0015] Accordingly, it is an object of this invention to provide a system and method for implementing a secure communications system.
[0016] It is another object to provide a system and method for encoding and decoding data.
[0017] It is yet another object to provide a system and method for secure distributed data storage.
BRIEF SUMMARY OF THE INVENTION
[0018] The present invention includes a communications channel, at least one terminal with an encoding device and at least one terminal with a decoding device. The encoding device transforms an applied message-to-be-transmitted M to a ciphertext C for transmission over the communications channel to the receiving terminal.
[0019] To clearly describe the symbol sequence level partition and permutation method, the symbol level permutation method is presented first. It is a special case of symbol sequence level permutation, where each of the symbol sequences comprises only one symbol.
[0020] Please note that the present invention included in this patent application specification is about symbol sequence level partition and permutation. The description of symbol level permutation only serves to delineate key concepts of symbol sequence level encryption.
[0021] The message M is an ordered symbol sequence of length k and can be represented as a k-tuple (m k , . . . , m 2 , m 1 ), k<=k max , where k max is the maximum symbol length of messages specified by the communications system. Please note that elements within parenthesis are counted from right to left in this patent application specification for consistency.
[0022] The symbols in message M can be defined as the minimum units for encryption. For instance, in on-line software release, the bits in binary executables are the minimum units for manipulation. Therefore, symbols refer to bits in this example. In ASCII message communications the minimum manipulation units are ASCII characters. Thus, symbols refer to ASCII characters.
[0023] The position of each symbol in M can be defined as another k-tuple (k, k−1, . . . , 2, 1). This information is trivial because it is the obvious original position of each symbol in M. However, this position information will be changed in permutation and can be defined as a secret key for encryption:
[0024] For example, an ASCII message ABCDEFGHI can be represented as a 9-tuple (A, B, C, D, E, F, G, H, I). The length of this symbol sequence is 9.
[0025] The position of each symbol in M can be represented as a 9-tuple (9, 8, 7, 6, 5, 4, 3, 2, 1), which is obviously trivial.
[0026] If the length of M is bigger than k max , then M can be transformed into blocks of length no bigger than k max , which are separately encoded and transmitted over the channel. The encoded blocks are separately decoded on the receiving terminal and transformed back to M. If the length of M is shorter than a minimum length, symbol permutation of M may still leak confidential information of message M. In this case, M can be padded to a longer sequence. Therefore, symbol permutation will not leak confidential information. The padded symbols will be dropped after decryption. These two cases apply to symbol sequence level permutation as well.
[0027] To obtain ciphertext C, the encoder permutates all symbols in M according to predefined ordering information (p k , . . . , p 2 , p 1 ), which is a permutation of (k, k−1, . . . , 1). p i is the position of symbol m i in ciphertext C, where 1<=i<=k. The k-tuple (p k , . . . , p 2 , p 1 ) is defined as the secret encryption key. There are a plurality of approaches to reduce the size of the secret key shared by both the encoding device and the decoding device.
[0028] For example, the ASCII message ABCDEFGHI can be permutated to a ciphertext EHGBICDFA according to permutation ordering information (p 9 , . . . , p 2 , p 1 )=(1, 6, 4, 3, 9, 2, 7, 8, 5), which is a permutation of (9, 8, 7, 6, 5, 4, 3, 2, 1). The 4 in the 9-tuple (p 0 , . . . , p 2 , p 1 )=(1, 6, 4, 3, 9, 2, 7, 8, 5) means that the 7 th symbol C in the message ABCDEFGHI is placed at the 4 th position in the ciphertext EHGBICDFA. Apparently, the secret key for this encoding is information (p 9 , . . . , p 2 , p 1 )=(1, 6, 4, 3, 9, 2, 7, 8, 5).
[0029] Another form of symbol level permutation encryption is involved with the secret key. In this form, the secret key is always a permutation of (k max , . . . , 2, 1) instead of a permutation of (k, k−1, . . . , 1). Accordingly, messages with length less than k max have to be padded to have length of k max .
[0030] For example, assuming k max is 15, the ASCII message ABCDEFGHI is first padded to ABCDEFGHI+JKLMN. Then the padded message is permutated to J EHKGLBIMC+DNFA according to (p 15 , . . . , p 2 , p 1 )=(1, 9, 6, 4, 14, 2, 11, 13, 8, 5, 15, 12, 10, 7, 3). Actually, because the positioning information for the remaining 6 padded symbols in the ciphertext is not important, only the first 9 elements in this 15-tuple are needed for decryption. Therefore, the encryption key can be reduced to 9-tuple (p 15 , . . . , p 8 , p 7 )=(1, 9, 6, 4, 14, 2, 11, 13, 8).
[0031] Unlike symbol level permutation, symbol sequence level permutation is performed at symbol sequence level. The encoding device first partitions M into n symbol sequences as (M n , . . . , M 2 , M 1 ). Each of M n , . . . , M 2 and M 1 is a symbol sequence within M and can be represented as:
(m j+si−1 , . . . , m j+1 , m j )
where m j is the starting symbol for M i , 1<=i<=n. s i is the length of M i , Thus, the partition can be characterized by (s n , . . . , s 2 , s 1 ).
[0033] For example, the ASCII message ABCDEFGHI can be partitioned into 3 symbol sequences AB CDE FGHI according to partition information 3-tuple (s 3 , s 2 , s 1 )=(2, 3, 4). The 3 in this 3-tuple means that the 2nd symbol sequence of this partition has 3 symbols, i.e. CDE.
[0034] Then (M n , . . . , M 2 , M 1 ) is permutated to (M 1n , . . . , M 12 , M 11 ) according to (p n , . . . , p 2 , p 1 ), which is a permutation of (n, n−1, . . . , 2, 1). p i is the sequence position of M i within the ciphertext (M 1n , . . . , M 12 , M 11 ), 1<=i<=n. The 1 in the subscript of M 1i denotes the first level permutation in case of recursive partition and permutation, which will be described in the following. The partition information (s n , . . . , s 2 , s 1 ) and permutation information (p n , . . . , p 2 , p 1 ) are defined as the secret encryption key.
[0035] In the previous ASCII message ABCDEFGHI, the message has been partitioned into (M 3 , M 2 , M 1 )=AB CDE FGHI according to partition information 3-tuple (s 3 , s 2 , s 1 )=(2, 3, 4). Then it is permutated to (M 13 , M 12 , M 11 )=CDE FGHI AB according to permutation information (p 3 , p 2 , p 1 )=(1, 3, 2). The 3 in (p 3 , p 2 , p 1 )=(1, 3, 2) means that the second symbol sequence CDE is placed as the third symbol sequence in the permutation. Please keep in mind that elements in parenthesis are counted from right to left in this application specification.
[0036] However, if necessary, the partition and permutation can be repeated recursively and sequentially on the resultant symbol sequences in a manner not necessarily same as previous partition and permutation until stopped by the encoding device. For instance, M 1i is one of M 1n , . . . , M 12 and M 11 , wherein 1<=i<=n, and can be further partitioned into n′ symbol sequences as (M 1in ′, . . . , M 1i2 , M 1i1 ) according to (s 1in ′, . . . , s 1i2 , s 1i1 ). s 1ij is the number of symbols in M 1ij , 1<=j<=n′. The 1i in the subscript means a partition on sequence M 1i . Then (M 1in′ , . . . , M 1i2 , M 1i1 ) is permutated according to (p 1in ′, . . . , p 1i2 , p 1i1 ), which is a permutation of (n′, n′−1, . . . , 2, 1). (p 1in ′, . . . , p 1i2 , p 1i1 ) and (s 1in′ , . . . , s 1i2 , s 1i1 ) may not be necessarily distinct from previous partitions and permutations respectively. The procedure of partition and permutation can be repeated recursively and sequentially on the resultant symbol sequences until stopped by the system.
[0037] For the recursive symbol sequence level permutation, the encryption key corresponds to information for all levels of partitions and permutations.
[0038] In the ASCII message ABCDEFGHI example, the message is already partitioned and permutated into symbol sequences (M 13 , M 12 , M 11 )=CDE FGHI AB. M 12 =FGHI can be further partitioned into (M 122 , M 121 )=F GHI according to (s 122 , s 121 )=(1, 3). The 3 in (1, 3) means that the first symbol sequence has 3 symbols, i, e, GHI. (M 122 , M 121 )=F GHI can then be permutated to GHI F according to permutation information (p 122 , p 121 )=(1, 2). The 2 in (p 122 , p 121 )=(1, 2) means that the first symbol sequence M 121 is placed as the second sequence in GHI F. As a result, the ciphertext is CDE GHI F AB.
[0039] In this recursive symbol sequence level permutation of ABCDEFGHI, the encryption key corresponds to (s 3 , s 2 , s 1 )=(2, 3, 4) and (p 3 , p 2 , p 1 )=(1, 3, 2) for partition and permutation on M, (s 122 , s 121 )=(1, 3) and (p 122 , p 121 )=(1, 2) for partition and permutation on M 12 .
[0040] Assuming M is partitioned into n symbol sequences, the number of possible combinations is factorial n!, which is larger than any exponential function in n. If the resultant symbol sequences are further partitioned and permutated, the complexity of encryption is further confounded. Therefore, assuming the resultant symbol sequences do not leak message confidential information, without the knowledge of the secret key, it is computationally infeasible to decode the ciphertext with current computing technology. As a result, symbol sequence level recursive partition and permutation provides sufficient information security for applications with no symbol level security requirement.
[0041] The partition and permutation information is used as encryption and decryption key. In some applications, a shared secret encryption key is established between the transmitter and the receiver per session basis. In this case, a distinct key is required for a separate communications session. This distinct encryption key can be encoded by other encryption techniques such as public key encryption techniques, thereafter being transmitted over the communications channel to the intended receiver. For this reason, it is important to shorten or reduce the size of the secret key.
[0042] There are a plurality of methods to shorten or reduce the size of the shared secret encryption key. For instance, same partition and permutation schemes can be applied, thus no need to transmit multiple partition and permutation information as the secret encryption key.
[0043] Alternatively, some conventional data compression techniques or hashing techniques can be applied on the secret encryption key to reduce the size of the key. When received by the intended receiver, the size-shortened key is converted back to the original secret key, which is applied on the decoding device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 shows a block diagram for a 2-way cryptographic communications system in accordance with the present invention.
[0045] FIG. 2 shows a detailed block diagram for an encoding/decoding device in the system in FIG. 1 .
[0046] FIG. 3 shows another embodiment of detailed block diagram for an encoding/decoding device in the system in FIG. 1 .
[0047] FIG. 4 shows a block diagram of another embodiment for a cryptographic communications system in accordance with the present invention.
[0048] FIG. 5 shows a block diagram of yet another embodiment for a cryptographic communications system in accordance with the present invention.
[0049] FIG. 6 shows in block diagram how to encode data and distribute the encoded data to storage terminals in a secure distributed storage system in accordance with the present invention.
[0050] FIG. 7 shows in block diagram how to collect distributed encoded data and restore the original data in a secure distributed storage system in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0051] Basic Configuration
[0052] FIG. 1 shows an embodiment of the present invention in block diagram form. This system comprises a communications channel 14 and two terminals A and B. The communications channel 14 in the embodiment in FIG. 1 is a two-way communications channel. Nonetheless, the communications channel consistent with the present invention may be one-way, 2-way or even multi-way in other embodiments. Each of terminals A and B includes encoding device 10 A and 10 B, respectively, and decoding device 12 A and 12 B, respectively. An encryption key key A is applied on both encoding device 10 A, which transforms a message M A to a ciphertext C A , and decoding device 12 B, which transforms the received ciphertext C A back to M′ A . Similarly, an encryption key key B is applied on both encoding device 10 B, which transforms a message M B to a ciphertext C B , and decoding device 12 A, which transforms the received ciphertext C B back to M′ B . In other embodiments of one-way communications from terminal A to terminal B, only encoding device 10 A and decoding device 12 B are required.
[0053] A plaintext message M A , represented as (m k , . . . , m 2 , m 1 ), can be partitioned into (M An , . . . , M A2 , M A1 ), k<=k max , where k max is the maximum message length allowed by terminal A. If the length of M is bigger than k max , then M is transformed into blocks of length no bigger than k max . The blocks are encoded and transmitted separately. On the receiving terminal, the blocks are decoded separately and transformed back to original message M. If the message length is shorter than the minimum symbol length, then M is padded before encryption to avoid potential information disclosure.
[0054] Symbol sequence M Ai , one of M An , . . . , M A2 and M A1 , is a symbol sequence within M A and its length is s Ai , where 1<=i<=n. When the length of each M Ai is one, this symbol sequence level permutation scheme is reduced to a symbol level permutation, therefore, symbol level permutation is a special case of symbol sequence level permutation.
[0055] In the operation of encryption, (M An , . . . , M A2 , M A1 ) is permutated to (M A1n , . . . , M A12 , M A11 ) according to (p An , . . . , p A2 , p A1 ), which is a permutation of (n, n−1, . . . , 2, 1). p Ai is where M Ai is placed within (M A1n , . . . , M A12 , M A11 ). This partition and permutation can be characterized by (s An , . . . , s A2 , s A1 ) and (p An , . . . , p A2 , p A1 ) respectively. Each M A1i can be further partitioned and permutated not necessarily in the same way as previously, wherein 1<=i<=n. This process can be repeated recursively and sequentially until stopped by the encoder. The final sequence of symbol sequences is defined as a ciphertext C A . The information including all levels of partition and permutation schemes characterized by (s An , . . . , s A2 , s A1 ) and (p An , . . . , p A2 , p A1 ) respectively is defined as the secret encryption key, key A . When necessary to reduce the size of the encryption key, same partition and permutation schemes can be applied. Moreover, conventional data compression and hashing techniques can be applied on the encryption key as well.
[0056] Please note that, to avoid information disclosure, it is required that the final resultant symbol sequences should not leak any confidential information. Otherwise, the process of recursive partition and permutation should be continued on those leaky symbol sequences until the information security is guaranteed.
[0057] In accordance with the present invention, an exemplary form for encoding device 10 A, 10 B and decoding device 12 A, 12 B is shown in FIG. 2 . The device in FIG. 2 includes an M memory buffer 26 for receiving an applied digital message-to-be-transferred, a key register 24 for receiving an applied digital encryption key and a memory buffer 28 for storing the encoded ciphertext C. The memory buffer 26 has K max entries and each entry stores one symbol of the message-to-be-transferred in either the top-down order or the bottom-up order as specified by the system. The memory buffer 28 also has K max entries with each entry storing one symbol of the encoded ciphertext C in an order as specified by the system.
[0058] The device further includes a finite state machine 20 and an address register 22 . The finite state machine 20 obtains the encryption key from key register 24 and generates a symbol address p i , which is written into the address register 22 . A message symbol m i , which is an output from message buffer 26 in an order specified by the system, is written into ciphertext memory buffer 28 at the address specified by p i . This is how the operation of permutation is implemented. It is required that the output of symbol address p i from address register 22 and the output of symbol m i from the message buffer 26 should be synchronized.
[0059] The device in FIG. 2 can operate in either encryption or decryption mode using the same encryption key. This is controlled by the finite state machine 20 when generating symbol address p i . If the encryption key is reduced by conventional compression or hashing techniques, the original encryption key can be recovered either before storing into the key register 24 , which is not depicted in FIG. 2 , or inside the finite state machine 20 .
[0060] Another embodiment of the encoding and decoding devices consistent with the present invention is shown in FIG. 3 . The M memory buffer 26 is replaced by a message symbol FIFO 30 . This is the only difference between the embodiment in FIG. 2 and the embodiment in FIG. 3 . After all symbols of the message are written into memory buffer 28 in FIG. 2 and FIG. 3 , the data in memory buffer 28 are read out in either the top-down order or the bottom-up order as specified by the communications system. This is the ciphertext C.
[0061] The embodiments in FIG. 2 and FIG. 3 can only perform permutation one symbol at a time, however, it is possible that the encoding and decoding devices may process more than one symbol at a time in other embodiments of the present invention.
[0062] Other Configurations
[0063] In the recursive symbol sequence level permutation encryption, every symbol sequence after previous partition and permutation can be partitioned and permutated distinctly and independently. Therefore, it is possible to process each of the symbol sequences in parallel. As embodied in FIG. 4 , a message M is partitioned and permutated according to key A0 by encoder 10 A0 , the resultant symbol sequence M s , which is one of M 1n , . . . , M 12 and M 11 , is de-selected by a 1-to-n de-selector (demux) 31 A to generate M A1i , where i is in the range of 1 to n inclusive. M A1i is applied on encoding device 10 Ai to generate C i using key Ai . C i is transmitted to terminal B over the channel 14 . Upon received by terminal B. C i is decoded by decoding device 12 Bi to obtain M′ 1i using key Ai , where 1<=i<=n. Then M′ s is selected from M′ 1n , . . . , M′ 12 and M′ 11 by a n-to-1 selector(mux) 32 B and is applied to decoding device 12 B0 . Thereby, message M′ is obtained, which should be the same as M.
[0064] As the decoding of C i is essentially the same as encoding of M 1 , where 1<=i<=n, it is possible to use a single decoder 12 B , as embodied in FIG. 5 . The terminal A in FIG. 5 is the same as that in FIG. 4 . The decoding schemes are different from that in FIG. 4 . Ciphertext C i is received and stored in memory buffer 34 Bi Then C s is selected from C n , . . . , C 2 and C 1 by a n-to-1 selector (mux) 38 B and decoded by the decoding device 12 B . Thereby, M′ is obtained, which is the same as M. The key used by decoder 12 B is generated by a key generator 36 B according to the particular symbol sequence fed to decoder 12 B .
[0065] In addition, the finite state machine 20 , as embodied in FIG. 2 and FIG. 3 , should be designed accordingly to generate correct symbol addresses.
[0066] The communications channel in both FIG. 4 and FIG. 5 is shown to have n physical links. However, there may be either multiple physical links or only one physical link to channel 14 . How C n , . . . , C 2 and C 1 are transmitted to the receiving terminal should be designed according to the specific communications channel.
[0067] There are other forms of encoder/decoder configurations consistent with the present invention in addition to the embodiments in FIG. 4 and FIG. 5 . The finite state machine and memory buffers inside the encoding and decoding devices, as embodied in FIG. 2 and FIG. 3 , should be designed accordingly. Moreover, the embodiments in FIG. 4 and FIG. 5 are one-way communciations system. Nonetheless, there can be other forms of the present invention capable of two-way or multi-way communications.
[0068] Secure Distributed Storage
[0069] The present invention can also be applied to secure distributed data storage as embodiments in FIG. 6 and FIG. 7 . FIG. 6 is an embodiment of the present invention for distributed data storage. It comprises an encoding and distributing terminal A, n distributed data storage terminals and a communications channel 14 . Terminal A comprises an encoding device 10 A, a 1-to-n deselector (demux) 42 A , and n memory buffers from 40 A1 to 40 An . The encoder 10 A partitions the message-to-be-stored into n symbol sequences (M n , . . . , M 2 , M 1 ) and permutates them into (M 1n , . . . , M 12 , M 11 ), which may be further partitioned and permutated. M 1i s are stored into memory buffers 40 Ai respectively and transmitted to n distributed storage terminals separately over channel 14 , wherein 1<=i<=n. The ith distributed data storage terminal includes a storage device 38 i , where the data is stored.
[0070] The embodiment in FIG. 7 describes how the distributed data is recovered. The n data storage terminals are the same as that in FIG. 6 . Terminal C, knowing the encryption key, receives C i s from the n storage terminals over channel 14 and store C i s in memory buffers from 46 C1 to 46 Cn respectively. The memory buffers feed C i s to decoding device 12 C via an n-to-1 selector (mux) 48 C . C i s are decoded by decoding device 12 C to obtain message M′, which is the same as original message M.
[0071] Conclusion
[0072] The present invention describes a recursive symbol sequence level partition and permutation method for cryptographic communications. It is required that the final symbol sequences in the ciphertext should not disclose any information confidentiality. Otherwise, the recursive partition and permutation process should be continued until information security is satisfied. The symbol level permutation method is a special case for symbol sequence level permutation. The present invention can also be applied to secure distributed data storage.
[0073] The following variations on the use of the encoding/decoding devices are to be considered as obvious to one skilled in the art and therefore within the intended scope of the attached claims:
1. Using encoders/decoders consistent with the present invention for messages that are either partitioned into smaller blocks to meet maximum message length requirement or padded into longer sequence to meet minimum message length requirement. It is also possible to steal symbols from other symbol sequence when particular symbol sequence is too short 2. Using encoders/decoders consistent with the present invention in conjunction with other types of encoders/decoders. Other encoders/decoders can be used either before or after encoders/decoders consistent with the present invention. Particularly, the symbols may be substituted, if needed, in encoding or decoding consistent with the present invention. The substitution symbols should also be considered as part of the secret encryption key in addition to the partition and permutation information. 3. Using a shared secret key established with other encryption schemes in implementations consistent with the present invention, 4. Using a secret key, size of which is shortened with conventional compression and hashing techniques, in encoding or decoding consistent with the present invention, 5. Implementing the present invention in software alone or hardware alone or as a combination of software and hardware, 6. Implementing the present invention as a standalone system, or embeded into or attached to another system.
[0080] The present invention has been disclosed and described with respect to the herein disclosed embodiments. However, these embodiments should be considered in all respects as illustrative and not restrictive. Other forms of the present invention could be made within the spirit and scope of the invention.
|
The present invention discloses a system and method for cryptographic communications. It may significantly improve operation efficiency of existing symbol level encryption algorithms by permutating at symbol sequence level with significantly less computational requirements. The system includes a communications channel, at least one terminal with encoding device and at least one terminal with decoding device. A message comprising ordered symbols can be partitioned into ordered symbol sequences. Then the order of symbol sequences is permutated by the encoding device. The partition and permutation can be repeated recursively on the resultant symbol sequences to obtain the ciphertext. All the partition and permutating information are characterized by a secret key, used for decoding on the receiving terminal. It is required that the final resultant symbol sequences in the ciphertext should not disclose information confidentiality. The present invention can be also applied to secure distributed data storage.
| 6
|
BACKGROUND OF THE INVENTION
This invention relates to disposable containers having a charge or pre-filling of a predetermined quantity of a liquid material to which a second liquid may, if desired, be added in order to produce a required solution of the liquid material.
There are available today various types of dispensing containers which are adapted to house a predetermined quantity of a material or product to be dispensed.
It is in particular known to provide a container with a lid formation which effectively divides the container into two compartments, of which one is used to house the predetermined quantity of the liquid material.
With the known systems difficulties have been found in providing a satisfactory mode of sealing in liquids which are able to vapourise readily and which are prone to contamination by the sealing-in process and/or by the materials used for the lid formation and the container.
SUMMARIES OF THE INVENTION
It is an object of the present invention to provide a precharged container which is able to house for lengthy periods a predetermined quantity of a liquid material without the material becoming contaminated.
It is a further object of the invention to provide a precharged container having two compartments one of which contains the predetermined quantity of the liquid material and which is sealed from the other compartment by a readily removable lid formation, which allows the precharged containers to be stacked.
A further object of the invention is to provide a precharged container which is able to house in the sealed compartment an alcoholic liquid without the latter loosing, as a consequence of being stored in the container, those characteristics which are considered to be important in relation to an alcoholic liquid used as a beverage.
According to a first aspect of the invention there is provided a method of hermetically sealing a predetermined quantity of alcohol or like liquid into a container of plastics material by means of a lid or cover applied to a predetermined zone of the wall of the container, the method comprising the steps of; forming a blank which is to provide the lid or cover from plastics or metallic material having the thickness of foil, the blank being of such size and shape as to be able to bridge the container, provide a marginal region that is securable to the zone, and also to provide after the securing a peripheral skirt region extending outwardly of said marginal region; supporting the blank in such manner that the marginal region can be caused to contact with the wall zone, bringing the marginal region into contact with the zone; simultaneously producing a temperature differential between said marginal region and said zone and predetermined pressure between the marginal region and the zone the temperature and pressure combination being such that following the removal of the temperature differential and the pressure the marginal region of the lid or cover is so secured to the container wall zone as to produce the hermetic seal whilst permitting removal of the lid or cover by a peeling action when it is required to break the hermetic seal.
A second aspect of the invention provides a method of hermetically sealing a liquid receiving chamber located at the lower section from a liquid receiving chamber located at the upper section of a stackable disposable container of plastics material, in which the two chambers connect with each other by way of a peripheral step or ledge between said chambers, the method including the steps of; forming a lid or cover producing blank from a plastics or metallic material having the thickness of foil, the blank being of such dimensions that it may be secured to the step or ledge and also to provide a peripheral skirt region; supporting the blank such that the blank may be brought into contact with the step or ledge; bringing the blank into co-operation with the ledge in such manner that the blank covers in the chamber; exerting pressure upon that part of the blank that is in co-operation with the step or ledge whilst simultaneously heating the said part to a temperature that following removal of the pressure and heating the part has been so adhered to the step or ledge as to produce a hermetic seal between the said part and the step or ledge whilst said peripheral skirt region is adhered to said container, said hermetic seal permitting subsequent removal of said lid or cover by a peeling operation.
Conveniently, a predetermined quantity of alcohol is introduced into the lower chamber prior to the securing of the lid or cover by guiding the alcohol to a location adjacent to the bottom of the container prior to the release of the alcohol into the chamber.
Preferably, the means for guiding the alcohol into the chamber includes a pouring spout having at its lowermost end outlet openings for the release of the alcohol, and having at its upper end inlet openings which are utilised as part of a control valve arrangement controlling flow of the alcohol through the pouring spout.
Preferably, the arrangements for supporting the blank include vacuum orifices whereby the blank is supported by suction effects, and in which the arrangements also serve to mount the means for heating the marginal regions of the blank and the associated part of the container and the means for producing the pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention and to show how the same may be carried into effect reference will now be made to the accompanying drawings in which
FIG. 1 is a cross-sectional view of a disposable container precharged with a quantity of a liquid material; the Figure illustrating a container as provided to a user;
FIG. 2 is a cross-sectional view of a container during an operation in which the predetermined quantity of liquid is introduced into the container; this figure schematically illustrating an apparatus for effecting the charging of the predetermined quantity of liquid;
FIG. 3 is a cross sectional-view of a container schematically illustrating an arrangement for securing a lid formation for sealing-in the liquid into the lower part of the container;
FIG. 4 is a cross-sectional view of a pre-charged container during an early stage in the preparation of the container so that the content may be imbibed; and
FIG. 5 is a further view of the stage of preparation shown in FIG. 4 but from a different direction.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and more particularly to FIG. 1 this Figure shows a container or beaker 1 having a generally tapered wall 2 defining an upper chamber 2a and which is stepped to provide a lower chamber 4 closed by a base 3 and having a smaller external diameter than the lowermost portion of the wall 2. The stepping defines a circumferential or peripheral ledge 5. This ledge defines a transition zone between the lower chamber 4 and the upper chamber 2a of the container 1 as represented by the wall 2.
The ledge provides a seating for the marginal regions 6 of a lid formation 7 which serves to seal-off the chamber 4 from the chamber 2a.
It will be noted that the side wall 8 of the chamber 4 is cylindrical and that the base 3 is slightly upwardly dished.
The chamber 4 is intended to be charged with a measured quantity of the liquid to be provided in the container. In particular the desired filling is constituted by an alcoholic beverage such as whisky, gin, vodka, brandy etc.,. It will be clearly understood that such materials have highly individual characteristics relating to frequently highly subjective factors so that it is extremely important that the liquid such as mentioned should not undergo any change or variation of the desirable characteristics during the charging of the chamber 4. Furthermore, it is also important that the filling process should not in any way wet the surface of the ledge 5.
Referring now to FIG. 2 this shows in essentially schematic form apparatus for introducing measured quantity of a liquid such as alcohol into a container chamber 4.
The apparatus includes a main container 9 of which only a fragmentary part is shown connecting at the lower part thereof with a secondary chamber 10, the latter having a volume which is equal to that of the chamber 4. The interior of the main container 9 connects with the chamber 10 by way of valve controlled outlet orifices 11. A valve plate 12 is provided with valves 13, one for each orifice 11. The arrangement of the valve plate 12 and associated valves 13 is that the latter are normally open.
A combined vertical guide tube 14 and second valve arrangement connects with the secondary chamber 10.
A vertically arranged pouring spout 15 is vertically slidably displaceable with respect to the guide tube 14. The spout is provided adjacent its upper end with orifices 16 which are co-operable with further orifices 17 in the guide tube. These orifices 16,17 operationally combine to provide a slide valve which latter forms the above mentioned second valve arrangement. The relative arrangement of the orifices 16 and 17 and the normal or rest position of the pouring spout 15 are such that the second valve arrangement is normally closed. The upper end of the pouring spout forms a valve operating head 18 which is adapted to co-operate with a valve operating element 19, which is positioned as to be able selectively to displace the valve plate 12 between its open and closed positions. A diaphragm 20 ensures fluid tightness between the head 18 and the plate 12.
The lower end of the pouring spout 15 is provided with liquid outlet openings 21. In addition, the lower end is shaped for contact with the base 3 of the chamber 4 of a container 1.
The relative arrangement and positioning of the components of the two valve arrangements discussed above is such that when the valves 13 are open the second valve arrangement is closed and such that on lifting the pouring spout vertically upwards relative to the guide tube to bring the orifices 16 and 17 into alignment the second valve arrangement is moved to its open position whilst the head 18 displaces the element 19 upwards thereby to lift the plate 12 and thus close the valves 13.
In order to fill the containers 1 with a measured amount of alcohol, the main container is filled with alcohol. Since the valves 13 are normally open the alcohol is able to pass from the container 9 into the chamber 10 by way of the orifices 11 since the valves 13 are open. The quantity of liquid entering into the chamber 10 is equal to the amount of alcohol it is required to introduce into the chamber 4 of a container 1.
The chamber 4 is filled by presenting the container to the apparatus in such manner that the inside of the base 3 is able to press against the lower end of the pouring spout 15 and lift the latter upwardly for a distance sufficient for the orifices 16 and 17 to align with each other. When this setting is obtained it will be found that the the valves 13 are moved to their closed positions thereby preventing further flow of alcohol from the container 9 into the chamber 10. In addition, as the second valve arrangement is now open the alcohol is able to flow down the spout 15 and pass out through the outlet openings.
Since the openings are very close to the base 3 of the chamber 4 the alcohol is able gently to flow into the chamber 4 without creating turbulance or splash likely to cause wetting of the ledge 5 and the lower regions of the container wall 2 in the near vicinity of the ledge.
It will be understood that, in practice, arrangements would be made to prevent leakages, and that the relative volumes of the chambers 10 and the interior of the spout would be such as to ensure that once the chamber 10 has emptied the correct quantity of alcohol has been introduced into the container chamber 4.
On the completion of the filling of the chamber 4 relative vertical displacement is effected between the apparatus for filling and the container. This movement allows the pouring spout 15 to return towards its rest or initial position. In so doing the second valve arrangement defined by the orifices 16 and 17 is reclosed and the valves 13 are enabled to re-open to allow the chamber 10 to become recharged with alcohol from the main container 9.
The above considered apparatus can form part of a more complex system in which a plurality of the containers may be charged simultaneously. It will also be understood that other forms of charging apparatus can be used provided that the apparatus used ensures that the introduction of the alcohol does not wet the ledge 5 or the container walls 2. Thus splash guard system could be used.
Following the charging of the chamber 4 it is necessary hermetically to seal the content of the chamber 4 so that the alcohol content can neither become contaminated nor evaporate or otherwise disappear.
Thus the chamber 4 is sealed by a lid formation 7. A possible mode of introducing the lid formation into the correct position within the containers 1 will now be considered in relation to FIG. 3.
In the FIG. 3 the container 1 is shown with the chamber 4 containing a charge or filling of a liquid such as alcohol in the form of a beverage such as whisky, gin, vodka, brandy or the like.
A support assembly 22 for carrying the blank which is to form the cover or lid 7 includes a plenum chamber 23 connecting with a number of suction orifices 24. The chamber 23 connects with a source of vacuum (not shown) by way of a vacuum line 25. The assembly itself is supported by a support system which enables the assembly to be lowered into a container so that the lid or cover forming blank may be brought into contact with the step or ledge 5 as is shown in the Figure.
The assembly is surrounded by a ring heater unit 26 which in the Figure comprises an annular member of the same dimensions in respect of its heating working face as that of the ledge 5. In other words the heating unit is able to heat the full surface area of the step or ledge 5 and that part of the blank for the lid or cover 7. The assembly is loaded in terms of weight so that when the heater rests upon the blank the required pressure for example, 2.5 to 3 pounds weight is produced. Alternatively the container and assembly 2 may be pressed towards each other to attain the desired contact pressure what ever the required magnitude thereof whether it is within or outside the particular range above mentioned.
In a particular example of securing the lid or cover 7 to the step or ledge 5 the ring heater unit 26 was heated to a temperature of approximately 150° Centigrade for a time period of approximately 0.5 seconds at a pressure of 2.5 to 3 pounds weight.
A pull tab 27 is secured to or is integral with the lid or cover 7. The tab is long enough to extend the full length of the wall 2 of the container 1 so as to be able to overhang the rim 28 of the container and to provide a short tab 29 which rests against the outside of the container. As can be seen from the Figures, and particularly FIGS. 4 and 5 the tab 29 is flush against the container wall.
It will be noted from the drawings that the lower chamber is of an essentially cylindrical form and that the upper chamber is shaped so as to provide a tapering. The resultant overall shaping of the container allows the containers 1 to be nested one within the other with the bottom of the lower chamber 4 resting upon the peripheral regions of the lid or cover 7 of the outer one of two successive nested containers. To facilitate the nesting the bottom 3 of the container is such as to provide an annular portion 30 which actually bears upon the lid or cover in the region of the ledge 5.
When it is desired to remove the lid or cover it is merely necessary to exert `pull` upon the pull tab 27 with a combined upwards and sideways movement.
The manner in which the cover or lid 7 is removed is essentially indicated in FIGS. 4 and 5. It is thought that a detailed description of the lid removal operation is not necessary in view of the content of these Figures.
As has been mentioned the lid or cover 7 when secured in place provides a peripheral skirt this is shown at 31 in the Figures. It has been found that the provision of the skirt 31 plays a significant part in the success of the sealing operation in that it is believed to provide a heat sink facility which ensures that the regions of the container wall 2 adjacent to the ledge 5 are protected from any undesired heating effect from the heating unit 26 which might lead to a weakening distortion of the container at such location. In addition, such heat protection arrangement prevents the container at the location in question from becoming blemished to an extent that the container becomes unsightly or otherwise unsuitable for marketing.
Furthermore, the formation of the skirt 31 provides a greater width to the base of the pull tab 27 at the region where the tab joins the remainder of the cover or lid 7. The formation of this wider region assists in avoiding the risk of undesired tearing occuring the pulling action, of the tab 27 from the remainder of the cover or lid 7. The skirt, furthermore, ensures that the free edge of the cover of lid 7 is not immediately adjacent to an adhered region of the cover or lid whereby any mechanical weaknesses such as incipient splits at the free edge cannot weaken the bond between the cover or lid and the ledge 5. One consequence of this is that the strength of the bond can be arranged to be greater than that practically possible with a lid or cover which is a precise fit within the container in the vicinity of the ledge 5.
As has been mentioned the lid or cover may be made from plastics or metallic foil. One such metallic material is Aluminium.* Also the container itself can be formed from any plastics material affording the acceptable characteristics. One such material is a clear polystyrene. The Aluminium needs to be sterile.
It has been found that the combination of the container and lid or cover secured as above discussed satisfies the criteria of acceptability in respect of regulations appertaining to the packaging of alcoholic beverages. In particular the relevant requirements of Part 117 of Title 21 of the Code of Federal Regulations (Food and Drugs) relative to the packaging of Alcoholic Beverages that do not exceed 50% Alcohol by volume are readily met.
|
A method of hermetically sealing a predetermined quantity of alcohol into a chamber provided at the bottom of a stackable disposable container of plastics material by securing a lid or cover having the thickness of foil to a ledge defined at the transition of the chamber with the remainder of the container. The method involves filling the container in such manner that the ledge is not wetted by the alcohol and than securing, by a combination of the effect of heat and pressure acting on the material of the cover and that of the ledge, the lid or cover to the ledge. Conveniently, a peripheral skirt is provided around the periphery of the lid or cover which is not adhered to the container.
| 1
|
This application is a continuation-in-part of application Ser. No. 268,341, filed Nov. 7, 1988 now U.S. Pat. No. 4,974,384.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to heavy construction attachment systems, in particular, to a system incorporating major disassembable units and to the units of the system.
2. Background of the Invention
In the construction industry, concrete foundations are commonly manufactured by using formwork into which concrete is poured. This formwork usually consists of re-usable wood and aluminum composite struts and joists which provide a supporting crib-work or lattice for the actual sheathing members onto which the concrete is poured. The sheathing frequently consists of plain or paper faced plywood members. Thus, a substantial plywood sheathing sheet for example 3/4 inch ply, having a replaceable paper liner as the casting surface, is usually nailed to an underlying supporting joist having an inset nailing strip. After the concrete has set, the underlying formwork lattice and plywood is removed. Frequently the plywood has to be torn down, owing to the entrainment of the attachment nails into the concrete. Similarly, the face of the plywood may be Penetrated by the concrete and become damaged. The wood nailing strips of the supporting laticework will become damaged over time due to repeated re-use and will have to be replaced. Considerable expenditures in material and labour costs are therefore involved, and valuable resources are used up.
The present method of manufacturing concrete foundations also has a drawback in that seam outlines of the 4×8 foot sheathing sheets, caused by misalignments, gaps and penetrating cement flashings must be ground away where a smooth finished surface is required.
The use of hook and loop elements for the purpose of joining flexible elements is not new. The garment and footwear industries have for many years employed a particular hook and loop type attachment material, commonly referred to by the trade mark VELCRO, for securing the adjacent surfaces of clothing and footwear. However, this material is limited both by the presently available widths, which do not exceed four inches, and by the maximum anchoring force developed by the plastic hook elements. Furthermore, prior usage appears to have been concentrated on the application of this type of fastener in areas where a peeling. wave-like relative movement can be used to attach and detach a pair of complementary hook and loop surfaces, as when opening a garment or a shoe flap or on the installation of decorative, non-structural panels such as shown in Wilson, U.S. Pat. No. 4,744,189 issued May 17, 1988 or room dividers such as shown in Curatolo, U.S. Pat. No. 4,090,335 issued May 23, 1978.
SUMMARY OF THE INVENTION
The present invention provides a building construction having a plurality of rigid standard components for assembly in layered, substantially planer facing relation, a first such standard component manufactured in standard lengths with a first part of a hook and loop fastening system along a surface of the standard component; a second such standard component having a second part of a hook and loop fastening system of complementary attachability to the first part along at least one surface of the second component, so that such components can be cut and fit as necessary in the building construction and engaged with each other by face to face detachable engagement between the first and second parts of the hook and lopp fastening system.
In one embodiment the building component portions may be positioned in substantially horizontally oriented, substantially planar relation.
In a further embodiment the building component portions may be positioned in inclined oriented relation, such as component parts of a partition wall.
In an alternative embodiment the construction may be temporary, having a plurality of layers, with attachment components secured in releasable joining connection between more than one pair of opposed interfaces of the construction layers.
The present invention discloses in one embodiment a system for manufacturing concrete structures in which re-usable hook and loop area fasteners are secured to component portions and used to attach formwork components in face-to-face mutually adherent, detachable relation.
In this embodiment one of the layers on which the formwork is erected may become embeded in and left with the concrete for later use in attaching finishing details such as surface decoration, rugs or wall paper.
The invention further provides an attachment system having releasable connecting elements for adhering to concrete, to enable the provision of removable and substitutable surface finish members in attached relation by way of the connecting elements to the concrete structure. Such surfaces may be walls, floors and/or ceilings.
The invention further provides a building system wherein a layer of first connecting elements is secured in permanently adhered relation to a first access face of a structure, to form an integral part thereof, for use in securing a second reverse face of a complementary structure in secured relation at the interface therewith, having a layer of second fastening elements located at the interface in engaging relation with the first layer of first elements.
Thus, a carpet or other floor covering having suitable fastening elements on the undersurface, or ceiling panels or tiles having appropriate fastening elements on the upper surface may be readily, detachably secured to an appropriate structure. Similarly, wall surfaces for partitions and the like can be attached to a stud system. Also, the elements of the stud system may incorporate such complementary layered fastening elements.
In one embodiment a lattice of supporting members includes at least a first face of a first member in pressing, adjoined relation with a second face of a second member, each member having secured thereto one component portion of a two component connecting means, to form a connecting interface between the members. Such a connection may be used in concrete formwork, or in a permanent floor joist and sub-floor construction, as well as in wall constructions.
In another embodiment, a structural member is provided with a surface connecting means component part in bonded relation to a first surface portion thereof, for use in attaching a second member having a second surface with a complementary surface connecting means in bonded relation thereto, for joinder of the first and the second members.
In another embodiment a structural member having a first surface with a layer of surface connecting means first component parts mounted to a backing sheet and bonded to the member is provided with a removable protective cover secured thereover in protective relation, the protective cover including on one face thereof a layer of surface connecting means second components complementary to the first components of the connecting means, to permit the attachment and removal of the protective cover and exposure of the surface layer of connecting means first components. Such an embodiment may comprise a floor and sub-floor construction, wherein the protective cover remains in place during the completion of construction, so as to protect the surface connecting means therebeneath. Subsequently, a carpet or other covering may be substituted wherein the protected underlying connecting components are utilized to removably secure the covering to the sub-floor.
In general, the area fastening elements of complementary hooks and loops are of synthetic material, formulated in layers attached to backing sheets to facilitate area coverage by way of the attachment means, so as to develop the requisite attachment strength.
BRIEF DESCRIPTION OF THE DRAWINGS
Certain embodiments of the invention are described, without limiting the invention thereto, reference being made to the accompanying drawings, wherein;
FIG. 1 is a general view of a concrete formwork system in accordance with the present invention, in partially exploded relation;
FIG. 2 is a general view of a structural floor system in accordance with the present invention;
FIGS. 3 and 4 are general views of structural elements incorporating component connecting means in accordance with the invention;
FIG. 5 is a sideview section of a poured ceiling or roof incorporating one element of a connecting means combination in installed relation therewith.
FIG. 6 is a view similar to FIG. 5, the ceiling incorporating the complementary elements of the connecting means combination.
FIG. 7 is a general view in exploded relation showing the elements of a portion of a partition wall embodying the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the making of the p resent invention it will be appreciated that certain inherent deficiencies and limitations of presently available hook and loop fasteners, such as the presently limited width of four inches in the VELCRO product, and the present upper limit on its gross developed joint strength can be overcome by the provision of wide width sheets of the respective hook and loop elements, the development of elements of improved characteristics and the adoption of improved manufacturing processes for the fasteners. An aspect of the components presented is the integration of a hook and loop fastening system into the surfaces of the products. What is described is an incorporation of this system directly into the elements comprising the building system. This aspect is required in order to provide the necessary flexibility of attachment when products are to be transported to the site as standard components or cut and fit on site for assembly into a building.
In addition, the invention presented in this application as well as previous application Ser. No. 148,711 filed Jan. 26, 1988 ANCHOR BOARD SYSTEM are not fastening products per se but rather are new designs of conventional building materials.
Referring to FIG. 1, a concrete formwork assembly 10 comprises a number of supporting struts 12 carrying beams 14 across which are laid joists 16, to which sheathing sheets 18 are secured.
A covering 41 overlays the gaps or joints 39 between adjoining sheathing sheets 18. At the interfaces 11, 22, 24 between the respective rigid components 14, 16, 18 area fastening elements comprising loops 27 and hooks 29 are located, to attach the respective components in securely anchored relation.
The covering 41 also utilizes area fastening elements comprising loops 27 and hooks 29 to secure it to the sheathing sheets 18.
Referring to FIG. 2, a portion 30 of a floor construction is shown. Illustrated are fabricated joists 32, each comprising a pair of opposed flanges 34, 36 having a web 38 secured therebetween. Such joists 32 can be of extruded light alloy such as aluminum, or fabricated of metal, or of wood and plywood as indicated.
The ends of joists 32 usually are supported by peripheral basement walls (not shown).
A subfloor comprising panels 40 is supported by joists 32. At the interface contact areas 46 and 47 are located area fastening elements secured to the respective components comprising loops 27 and hooks 29, to hold the respective components in mutually anchored relation. A flexible, protective cover sheet 50 overlies the upper surface of floor panels 40, being arranged to cover the floor panel intermediate gaps or joints 39.
During the erection of a building, sheet 50 may comprise a protective over-flooring element, to safeguard the underlying, upwardly extending hook Portions 29 against damage from above. Once the building is erected and the finishing work completed, the protective sheet 50 can be removed and 4×8 sheets of plywood for a flooring system having a complementary loop layer on the underface thereof or a covering carpet with a looped underface, as disclosed in my copending application Ser. No. 136,953 can be installed.
FIG. 3 shows a substantially rigid panel 50 having a layer of loop elements 27 on one face thereof. This panel may comprise a finished surface element, which can be attached to installed hook elements 29 of a construction.
In the case of a poured ceiling surface, as illustrated in FIGS. 5 and 6, respective surface area attachment elements 54, 56 can be secured in situ at the time of pouring the concrete ceiling, or subsequently applied thereto. The enhanced utility achieved in making the surface area elements 54 or 56 as part of the formwork illustrated in FIG. 1, by appropriate adaptations, can be readily appreciated. Thus, in the case of the ceiling embodiment referred to in the FIG. 1 arrangement, a covering 41 may be either releasable so that it does not attach to the concrete or it may include upwardly extending loops or hooks, so as to bond the covering 41 to the undersurface of a ceiling that is poured thereover. It will be understood that the undersurface of covering 41 also is provided with hooks or loops, the selection of loops or hooks being appropriate to the fastening elements incorporated with the finish ceiling surface to be suspended therefrom. Further, fastening elements complementary to the selected elements of the undersurface of covering 41 will be secured to the upper surface of sheathing sheets 18, to enable detachable attachment of covering 41 to sheets 18, to facilitate initial assembly, and subsequent disassembly of the formwork.
FIG. 4 illustrates a panel 60 having a layer of loop elements 27 and hook elements 29 thereon, for use as an intermediate construction.
In operation, referring first to FIG. 1, a supporting grill work of elements 12, 14, 16 is erected. The presence at the respective interface areas of the hook/loop area attachments permits assembly without nailing or other auxiliary fastening steps. Similarly, the sheathing sheets 18 are readily positioned in place and secured by the weight of the sheeting, together with the temporary application of downward force thereon, to engage the respective loop and hook elements 27, 29.
The barrier sheet 41 protects the upper surface of the sheathing sheets 18 so that liquid concrete cannot penetrate between adjacent sheets 18. This minimizes the need for subsequent joist-flash grinding.
In the case of the sheathing sheet members 18, it is contemplated that they may be fabricated of materials other than Plywood, such as aluminum composites having a foam core, in order to reduce the weight of these members while maintaining adequate structural strength and rigidity.
The barrier sheet 41 may have a treated upper surface thereon, to facilitate bonding with the concrete when it is poured, or a surface barrier layer which precludes such bonding. Also, the upper surface of sheet 41 may have recesses or protrusions, to facilitate in-situ bonding to the poured concrete.
In FIG. 2, suitable floor joists such as the illustrated prefabricated joists are installed at the requisite intervals. The joists 32 may also incorporate area attachment elements in accordance with the present invention at their end lower surfaces to facilitate their installation. The sub-floor panels 40 are then positioned in place where temporary downward force will engage the interface fastener elements, loops 27 and hooks 29.
A protective flexible sheeting 50 then is laid over the sub-floor, so as to cover the intermediate joists 39. The purpose of the sheeting 50 is to protect hook elements 29 of the subfloor panels 40. Once construction activity, such as that of the allied trades, electricians, plumbers, carpenters is completed, a carpet having a looped undersurface in accordance with my copending application Ser. No. 136,953 can be substituted for the sheeting 50.
In dissassembling the subject system it will be understood that, owing to the potentially large securing forces that can be generated between the interface attachment hook and loop means, the use of auxiliary mechanisms, such as pry bars or pulling mechanisms may be required.
Referring to FIG. 7 a portion of a Partition wall assembly 70 is shown. A sill piece 72 of U-section, having fastening elements 73 therein receives a stud member 74 in inserted relation. An end under-face of portion 75 of stud member 74 has fastening elements 77 thereon, to engage the fastening elements 73 of sill piece 72. The side portions 78 of stud member 74 have the outer faces thereof covered or at least partially covered with fastening elements 77, to which the elements 73 of sheet 79 can adhere. In use a partition wall can be readily and rapidly assembled to provide a partition wall of adequate strength, yet which can be readily disassembled. The sill piece 72 may also be provided with attachment elements 73 or 77 on the underface thereof. The partition wall elements 72 and 74 are generally of rolled metal, of thin section, similar to the metal studs and sills presently used with nailing constructions.
It will be understood that the foregoing disclosed embodiments are illustrative of the invention, and modifications thereto can be made, within the scope of the claims appended hereto.
|
Re-attachable structural assemblies incorporating complementary area fastening elements comprising hook and loop elements over extended rigid contact surfaces between structural members of an assembly are disclosed for use in the construction industry in relation to: temporary formwork for casting concrete; precast concrete components for permanent installation of finished surfaces; and, fabricated floor and wall systems including joists, sub-floors, and floor covering surface units. The use of synthetic hook and loop attachment systems affords significant savings in time, labor, and frequently in materials, particularly in the temporary formwork application.
| 4
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the priority of the PCT application PCT/US2006/027518 filed on Jul. 14, 2006, which, in turn, claimed the priority of the filing of the U.S. provisional patent application 60/699,445 filed on Jul. 15, 2005, of which the present application also claims the priority.
BACKGROUND
[0002] K. A. Kelly et al., in their U.S. Pat. Nos. 5,738,637, issued Apr. 14, 1998, 6,234,984, issued May 22, 2001, 6,325,771, issued Dec. 4, 2001, and 6,645,163, issued Nov. 11, 2003, as well as their U.S. patent application Ser. Nos. 9/818,102, filed Mar. 27, 2001, and 10/705,487, filed Nov. 11, 2003, have provided a remarkable manual device for effectuating CPR on a patient suffering cardiac arrest. The disclosures of these patents and applications are incorporated here by reference. The CPR device of Kelly et al. permits the quick, correct, facile and reliable, manual application of CPR to a person suffering cardiac arrest.
[0003] Prior concepts of CPR have focussed on two separate lines of thought. The first of these has instructed individuals to place their hands on the chest of the person in extremis and push down in a repeated cycle. This unassisted CPR suffers from several limitations. Foremost amongst these is the fact that very few individuals, even those supposedly trained in such CPR, can accomplish the task correctly to provide a significant improvement in the patient's chances of surviving the emergency. Further, this type of CPR has only succeeded in placing a force acting downward on the chest of the victim. While this may produce some desired blood flow, it entirely ignores the significant potential of increasing circulation by constricting the person's chest. Not surprisingly, this type of CPR has not proven particularly successful in saving lives of individuals suffering cardiac arrest.
[0004] The second type of CPR procedure does the opposite from the first: It circumvents the individual's chest with some sort of sleeve that then undergoes constriction to squeeze the chest and increase the desired blood flow as discussed above. A pneumatic sleeve with an air pressure device often powers this type of apparatus. However, this type of CPR typically fails to a provide downward force into the chest to achieve that assist to the circulation discussed with regards to manual CPR discussed above. Further, this type of apparatus typically requires a substantial financial investment and also necessitates significant training to assure its proper attachment to a patient and subsequent operation, even when “automated.” Notwithstanding the foregoing, significantly improved examples of this type appear in U.S. Pat. No. 4,770,164 issued on Sep. 13, 1988, to R. Lach et al. as well as in the Kelly et al. patents and applications listed above. In fact, the latter show an automated apparatus accomplishing both types of CPR forces, downward and circumferential, discussed above.
[0005] Substantial interest has focussed on the ready use of defibrillation on persons suffering from cardiac arrest. While this process has a significant place in the treatment of such persons, it does not aid in bringing oxygen to the heart so that it can function upon defibrillation.
[0006] The manual CPR apparatus shown in the Kelly et al. patents and applications facilely accomplish both types of circulation assistance. It allows the downward force placed on it to pass directly into the chest of the patient to effectuate the radial force that directly depresses the chest. However, it also tightens a belt placed around the patient's chest to constrict it and the patient's chest to achieve further and important circulation around the heart muscle.
[0007] Significantly, the Kelly et al. device requires a minimal financial investment and virtually no training. This allows its placement in many and varied locations, such as the trunks of police squad cars and at gymnasiums and its use by individuals, such as the police themselves and others like coaches and other institutional personnel. In its simplest form, this CPR apparatus utilizes a belt placed around the victim and attached to a mechanism. When the operator pushes down on the handles forming part of this mechanism, some of the downward force passes straight through to the patient in the form of a radial force directed inward from his or her sternum into the chest. Significantly, the device converts part of the applied downward force into a tangential component that effects a circumferential tightening of the belt around the chest to squeeze it and further promote blood circulation around the heart.
[0008] While the Kelly et al. device described in its simplest form above has proven effective for persons with cardiac arrest, the patent and applications listed above disclose many additional features that may enhance its effectiveness in particular situations. Thus, the device may include a backboard to which the belt attaches or through slots in which the belt passes. The backboard may also have a raised portion for the patient's head, and the raised portion may house breathing apparatus and gas (such as oxygen) for the patient.
[0009] As other sophistications, the Kelly et al. device may include a force sensor to indicate the pressure applied to the victim's chest. An indicator of this force may then allow the operator to achieve more effective and safe treatment.
[0010] As a further safety feature, the apparatus may include a device for limiting the amount of circumferential tightening applied to the patient's chest. In particular, this feature may allow a choice between several different forces applied around the chest.
[0011] To assure full chest expansion between down strokes, Kelly et al.'s device may incorporate a component on its chest-contacting surface for adhering the device to the chest. Upon the release of pressure, this adherence will assist to expand the chest by pulling up on the patient's torso. This adhering device may take the form of suction cups or even some form of adhesive.
[0012] Kelly et al. also suggest a signal generator forming part of their device. This component has the purpose of producing a periodic signal. This signal simply informs the operator when to push down on the apparatus and helps achieve a rhythmic application of force at the interval that portends the greatest positive effect on the patient.
[0013] The apparatus may also include two or more electrodes, spaced apart from each other, that contact the patient's chest at different locations for the purposes discussed below. Two electrodes may attach to the base of the device which sits on the chest. Alternately, one may attach to the base while a second connects to the belt. Or, the two may attach at different locations along the longitudinal axis of the device's belt. Or, with more, the electrodes may attach to the belt and at several locations around the belt.
[0014] The electrodes may serve to obtain an electrocardiogram of the patient. Alternately or additionally, the electrode may defibrillate the heart when necessary.
[0015] As seen from the above, the Kelly et al. device has provided vastly improve CPR to individuals in dire need of such treatment. Naturally, the work continues to improve this mechanism even further.
SUMMARY
[0016] An improved apparatus for increasing the flow of blood in a patient will typically include a base contoured to seat near a central region of a patient's chest, an actuator, and a substantially inelastic belt means configured to wrap around the patient's chest substantially in a plane. A force converter then mounts on the base and couples to the actuator. This converter has belt connectors that couple to opposite extremities of the belt means with the belt means substantially in the plane described above. The converter serves to convert into belt tightening resultants applied to the belt connectors and directed substantially tangentially to the chest a force applied to the actuator at two separated points along a line making a nonzero angle to the plane of the belt means and directed toward the chest.
[0017] The Kelly et al. device carried two handles for the operator to apply a force to by pushing down on at separated locations for the CPR. The handles were separated by a line that actually lay in the plane defined by the belt. Stated in other words, the separation between the handles lies across the patient's chest, or, more accurately, perpendicular to the patient's longitudinal axis. This then requires the operator to straddle the patient or to try to configure his or her own body in an unnatural configuration to achieve the downward force on the two handles. The new device described above obviates this problem from the Kelly et al. device by moving the separation of the handles away from the plane of the belt that circumnavigates the patient's chest. This allows the operator to assume a more natural position along the side of the patient.
[0018] More particularly, the line separating the two handles may lie substantially perpendicular to the plane of the belt means. Stated alternately, the line separating the two handles, or the force points, lies substantially parallel to the longitudinal axis of the patient's torso. In either instance, the operator may facilely grab the handles to perform the life-saving function.
[0019] Rather than focussing upon the plane of the belt means that circumvents the patient, a description of an improved CPR device may focus on the points of attachment of the opposite extremities of the belt means to the belt connectors of the force converter. These two points generally define a first line. The converter then converts into belt tightening resultants applied to the belt connectors directed substantially tangentially to the chest a force applied to the actuator at two separated points along a second line making a nonzero angle to the first line and directed toward the chest. As suggested above, the preferred location of the second line along which the operator applies his or her force lies substantially perpendicular to the first line defined by the points of attachment of the opposite extremities of the belt means to the belt connectors of the converter. Or, the first line along which the operator applies the force lies substantially parallel to the longitudinal axis of the torso of said patient.
[0020] A method of CPR treating a patient, as indicated above, commences with seating a base of a blood flow increasing apparatus on a patient's chest near a central region of that chest. It then includes wrapping a belt means with first and second opposite extremities around the patient's chest, with the belt means itself substantially forming a plane. Any of the extremities of the belt means not already fastened to the apparatus are, accordingly, fastened to it, with the belt means substantially forming a plane. At this point, a force is applied at two separated points along a line making a nonzero angle with the plane defined above and directed toward the chest to an actuator coupled to a converter. The converter is, of course, coupled to the base and the belt means. Lastly, the force is converted into belt tightening resultants directed substantially tangentially to the chest.
[0021] Preferably, the line along which the force is applied lies substantially perpendicular to the plane defined by the belt means. Or, this line lies substantially parallel to the longitudinal axis of the patient's torso.
[0022] Alternately, the first and second extremities of the belt means are separated from each other substantially along a first line when fastened to the apparatus. A force is then applied toward the chest at two separated points along a second line making a nonzero angle relative to the first line and directed to an actuator coupled to a converter which in turn couples to the base and the belt means. Lastly, the force is converted into belt tightening resultants directed substantially tangentially to the chest. As above, the first line may lie substantially perpendicular to the second line, or alternately, substantially parallel to the longitudinal axis of the patient's torso.
BRIEF DESCRIPTION OF THE FIGURES
[0023] FIG. 1 shows an operator employing an improved device to administer CPR force from the side of a patient and along a line parallel to the patient's torso.
[0024] FIG. 2 gives an end view along the line 2 - 2 of the CPR device of FIG. 1 but without the operator.
[0025] FIG. 3 provides a similar view of the CPR device of FIGS. 1 and 2 but with a downward force exerted on the device's handles.
[0026] FIG. 4 shows an isometric view of the CPR apparatus of FIGS. 1 to 3 .
[0027] FIG. 5 displays the components of the CPR device of FIGS. 1 to 4 in exploded view.
[0028] FIG. 6 gives an isometric view of the CPR apparatus of FIGS. 1 to 4 and very similar to that of FIG. 4 in particular but in a depressed, or compressive, state.
[0029] FIG. 7 illustrates a CPR device the same as that in FIGS. 1 to 6 with a view very similar to that in FIG. 3 but including the use of a backboard.
[0030] FIG. 8 shows, in an isometric view, a CPR device allowing the application of any of a number of preselected CPR forces somewhat similar to that seen in FIGS. 13 to 17 of the incorporated Kelly et al. patents and applications but permitting the location of the force at any two points around a circle relative the patient's torso.
[0031] FIG. 9 gives an end elevational view along the line 9 - 9 of the CPR device shown in FIG. 8 with the compressive configuration in phantom.
[0032] FIG. 10 provides an isometric view of a CPR apparatus utilizing a converting unit similar to that of FIGS. 1 to 7 but allowing the application of force at any two points around a circle over the patient's torso.
[0033] FIG. 11 portrays a side elevational view along the line 11 - 11 of the CPR device of FIG. 10 .
[0034] FIG. 12 gives an end elevational view along the line 12 - 12 of the CPR device of FIG. 10 and showing the compressive state in phantom.
[0035] FIG. 13 has an enlarged view along the line 13 - 13 of the belt attaching mechanism of the CPR apparatus of FIG. 10 .
[0036] FIG. 14 provides an isometric view of an alternate CPR apparatus allowing the application of force along a line parallel to the patient's torso and in which the belt ends raise upward upon the application of a compressive force.
[0037] FIG. 15 has the same view of the same CPR apparatus of FIG. 14 but with the belt and one side removed to illustrate the working of that device's mechanism.
[0038] FIG. 16 gives a cross-sectional view along the line 16 - 16 of the CPR device of FIG. 14 .
[0039] FIG. 17 portrays a CPR device virtually identical to that of FIGS. 14 to 16 except that it uses a suction cup to contact the patient's chest to assist in chest expansion between force applications.
DETAILED DESCRIPTION
[0040] FIGS. 1 to 7 show the CPR device generally at 30 attached by the belt 31 to the patient 32 undergoing CPR treatment. As seen particularly in FIGS. 1 to 3 and 7 , the belt 31 generally defines a plane as it circumvents the patient 32 . The handles 33 and 34 of the CPR device 30 lie (and are separated from each other) along the line 35 . The line 35 , in turn, generally forms a perpendicular angle with the plane of the belt 31 . It also lies generally parallel to the longitudinal axis 36 of the patient 32 .
[0041] This orientation of the handles 33 and 34 allows the operator 40 to kneel or otherwise position himself or herself along the side of the patient 32 and facilely place his or her hands 41 and 42 on the handles 33 and 34 , respectively, to effectuate CPR. The operator 40 need not straddle the patient 32 or assume some other inconvenient or less effective position.
[0042] To administer CPR, the operator 40 places the belt 31 around the patient's back and the apparatus 30 on the patients' chest. He or she then attaches the belt ends 45 and 46 to the device 30 . Specifically, the ends 45 and 46 wrap around the rods 47 and 48 and attach there using such standard couplings such as hooks and loops, any of the connections shown in Kelly et al.'s patents and applications, or the quick release clamp discussed below with regards specifically to FIG. 13 . This produces the configuration shown in particular in FIGS. 1 , 2 , and 4 .
[0043] The operator then pushes downward on the handles 33 and 34 . This accomplishes two tasks. First, the device 30 transmits a downward force directly onto the sternum of the patient 32 to directly compress the chest. This provides the first component of the CPR.
[0044] Second, pushing down on the handles 33 and 34 forces their interconnecting bar 53 to descend, with its bearings 55 and 56 , along the openings 57 and 58 in the sides 59 and 60 , respectively, of the U-bar 61 , permanently affixed to the base 62 . The bar 53 , in turn, surrounded by the bearings 65 and 66 , passes through the openings 67 and 68 in the triangular side plates 69 and 70 , respectively, as clearly seen in FIG. 5 . Thus, pushing down on the handles 33 and 34 causes the bar 53 to force the side plates 69 and 70 to travel downwards as well.
[0045] The plates 69 and 70 moving up and down forces the levers 75 to 78 to rotate around their respective pivot points 81 to 84 , respectively. To see this, the bolt 85 journals the pivot points 81 and 83 of the side plates 75 and 77 , respectively, to the opening 89 in the base 62 while similarly the bolt 86 rotatingly connects the pivot points 82 and 84 to the base 62 . In turn, the bolt 91 passes through the slot 93 in the side plate and journals to the upper arm 95 of the lever 75 . With the bar 53 in its raised position, the bolt 85 sits towards the interior of the side plate 69 as particularly seen in FIGS. 2 and 4 . Pushing down on the handles 33 and 34 forces the plate 69 to move in the same direction which, concomitantly, forces the bolt 91 to move downward and, at the same time, towards the outside of the slot 93 . This forces the lever 75 to rotate in the counterclockwise direction in FIGS. 4 and 5 , the upper arm 95 of the lever 75 to move downward, and the lower lever arm 97 to travel upward all around the pivot point 81 to the position seen in FIGS. 3 , 6 , and 7 .
[0046] Exactly the same takes place with regards to the lever 76 which has its upper arm 102 slidingly affixed to the side plate 70 by the bolt 104 which passes through the slot 106 and moves along it. An exactly analogous analysis shows that pushing down on the handles 33 and 34 causes the lever 76 to rotate in the counterclockwise direction, in FIGS. 4 and 5 , its upper arm 102 to descend, and its lower arm 108 to elevate. Thus, in summary, pushing down on the handles 33 and 34 forces the lower arms 97 and 108 of the levers 75 and 76 , respectively, to raise. However, the bar 48 , to which the end 45 of the belt 31 attaches, is itself connected to the lower lever arms 97 and 108 . Thus, pushing down on the handles 33 and 34 raises the belt end 45 and tightens the belt 31 .
[0047] Exactly the same thing happens to the other belt end 46 . Pushing down on the handles 33 and 34 causes it to also raise and tighten the belt 31 . As a consequence, a downward force on the handles 33 and 34 both depresses the chest of the patient and tightens the belt around it, as seen in FIGS. 3 and 7 .
[0048] The latter FIG. 7 shows the use of the CPR device 30 on a patient 32 placed on the backboard 121 . As seen there, the belt 31 passes through the two openings 123 and 124 . To facilitate the use of the CPR apparatus 30 , the backboard may permit the semipermanent attachment of the belt 31 for quicker use when needed. The backboard 121 may contain any or all of the features shown for such an item in the patents and applications of Kelly et al.
[0049] Additionally, as seen in FIGS. 4 and 5 , the lockpin 127 fits into the opening 128 of the side plate 69 , and with the handles 33 and 34 in their raised position, the openings 129 , 130 , and 131 of the levers 75 and 77 , and the U-bar 59 , respectively. This keeps the device 30 in the elevated configuration shown in FIG. 4 to permit the taut attachment of the belt 31 immediately prior to use and prevent possibly deleterious movement when not in use.
[0050] As seen in the above figures, the levers 75 to 78 have the unique shape of T-bases with the upper arms bent 90 degrees to the horizontal (as seen there). This allows the upper arms to move to their descended positions seen in FIGS. 3 , 6 , and 7 without interfering the raising of the ends 47 and 48 holding the belt ends 45 and 46 to tighten the belt 31 . In the tightened position seen in these figures, the bars 45 and 46 actually nestle in the 90 degree bends of the upper lever arms.
[0051] FIGS. 8 and 9 show a CPR device generally at 150 built upon the unit shown in FIGS. 13 to 17 of the Kelly et al. patents and applications. Without repeating the analysis contained there, the device has the two over-center levers 151 and 152 that pivot about the point 153 . The belt ends attach to the bars 157 and 158 connected to the respective lever arms 159 and 160 of the levers 151 and 152 . As seen from the perspective of FIG. 9 , the belt end from the right in the figure will attach to the bar 157 and the belt end from the left attaches to the bar 158 . In turn, the lever arm 159 separates the bar 157 (and the right belt end) from the pivot point 153 and the lever arm 160 does the same action for the left-belt-end bar 158 .
[0052] As the levers 151 and 152 pivot about the point 153 , the bars 157 and 158 move upward and towards each other. This causes the ends of the belt attached to these bars to similarly move upwards and toward each other and tighten the belt about the torso of the CPR patient.
[0053] The stop pin 163 serves to limit the amount of rotation of the levers 151 and 152 about the pivot point 153 . In particular, placing the pin 163 in the opening 164 permits the least amount of such rotation while placing it in the openings 165 and 166 allows ever increasing rotation and thus tightening of the belt about the patient's chest. Removing the pin 163 eliminates the barrier to rotation altogether should that prove necessary.
[0054] To operate the CPR device 150 , the attendant pushes down on the wheel 171 . The exact location where the operator places his or her hands does not matter to any particular degree. However, for balance, locating the pressure points on generally opposite sides of the wheel 171 would appear somewhat desirable. In particular, the wheel 171 permits placing the hands at two locations separated by a line lying generally parallel to the bars 157 and 158 . However, these bars 157 and 158 , with the belt surrounding the patient's chest and attached to them, lie generally parallel to the patient's longitudinal axis and also perpendicular to the plane defined by the belt circumnavigating the patient. The two posts 173 and 174 rigidly attach the wheel 171 to the side plate 175 , and the posts 177 and 178 connect it to the plate 179 . Thus, the operator's pushing down on the wheel causes the side plates 175 and 179 to descend. It also causes a downward pressure on the patient's chest.
[0055] As the side plates 175 and 179 descend, they similarly cause the rod 181 , coupled to the upper lever arms 159 by the caps 183 which also pass through the slots 185 , to move downward. At the same time, the rod 188 , coupled to the plates 175 and 179 by the caps 190 which pass through the slots 192 , also goes down and takes with it the upper lever arms 160 . Thus, pushing down on the wheel 171 at any points around its circumference causes the levers 151 and 152 to pivot about the point 153 which has the effect of pulling up on the belt ends by the 157 and 158 to tighten it circumferentially about the patient's chest. This action is in addition to the direct downward force exerted on the patient's chest discussed above.
[0056] FIGS. 10 to 12 show the CPR apparatus generally at 201 that operates in virtually the same manner as the device 30 in FIGS. 1 to 7 and includes a substantial number of important additional features. Initially, the manual operation of the apparatus 201 involves the attendant pushing down on the wheel 202 . The wheel 202 , in turn rigidly connects to the side plates 203 and 204 though the struts 205 to 208 and causes then to descend at the same time. As with the device 30 in FIG. 1 , the downward motion of the side plates 203 and 204 first places a depressive force on the patient's chest 212 . It also causes the levers 215 and 216 to rotate about their pivot point 217 and the levers 219 and 220 to rotate about their pivot point 221 to raise the belt ends 225 and 226 and circumferentially constrict the chest 212 in exactly the same fashion as the device 30 in FIGS. 1 to 7 . The only difference in the two devices 30 and 201 in their mechanical operation is that the operator places his or her hands at most any generally opposed points on the wheel 202 in FIGS. 10 to 12 whereas the operator must grab the opposed handles 33 and 34 in FIGS. 1 to 7 . This gives the device 201 an additional degree of flexibility not provided by the device 30 .
[0057] However, the CPR device 201 of FIGS. 10 to 12 has numerous other features that enable it to perform its life-saving function in many different advantageous ways. Thus, as seen in FIGS. 10 and 12 , the base 231 of the CPR device 201 includes the combined electrocardiogram (“EKG”) and defibrillation (“defib”) and possibly pressure sensitive pad 232 . Similarly, the belt 233 incorporates the EKG-defib pads 234 to 236 . The pads 232 and 234 to 236 have the usual functions indicated by the terms EKG and defibrillation. These pads couple to the wire 237 which may serve as an antenna or a quick connect and disconnect device through the plug 238 . The wire may embed within the belt 233 . The plug may allow for connection to an external computer or other device for monitoring the patient. It may also allow connection to a telephone or other device for transmission of its signals to other stations, and it may also indicate its own location.
[0058] Additionally, the CPR equipment 201 includes the electronic pack indicated generally at 243 that provides a variety of functions to aid in the task of saving a patient's life. First it may have the EKG display 244 which connects, in turn, to the pads 232 and 234 to 236 . This provides a skilled operator with an indication of the patient's condition and progress. Next to the EKG display 244 , the pack 243 may include the visual indicator 245 which tells the operator when to push down and complete a stroke. Most conveniently, the indicator 245 may take the form of a light that shines when it wishes for a CPR stroke.
[0059] The pack 243 also incorporates the display gauge 251 that indicates the pressure exerted by the operator's downward stroke. This informs the operator if he or she is providing adequate force to achieve effective CPR. The gauge receives its input from a pressure pad that may have a colocation with or form part of the EKG-defib pad 232 .
[0060] The speaker 252 may provide an audible signal to indicate that a compression should occur. It could also provide verbal directions to facilitate the attachment and use of the CPR device 201 itself. Sitting next to the speaker 252 , the on-off switch 253 controls the overall operation of the pack 243 . As seen best in FIG. 11 , the pack 243 also includes the computer 261 that controls the pack's other functions. It may also incorporate security features such as passwords or biometric measurements to identify the attendant and limit access to the operation of the pack 243 . The computer 261 may also record and store information concerning the actuation of the equipment and the signals generated by it. In particular, the computer 261 can monitor the overall operation of the device and determine the most advantageous times to compress, ventilate or defibrillate the patient based in part on signals received from the pads 232 and 234 to 236 . It can then operate the components that achieve these functions. The battery 262 then provides the power for the other components discussed above.
[0061] Additionally or separately, the pack 243 nay include the fluid piston or electrical motor 267 that can assist in the operation of the device 201 or operate it itself. It can receive its fluid or electrical power though the coupling 268 that connects to the electrical or fluid cable 269 , as appropriate. The cable 269 then passes to the control assembly 270 which includes the gauge 273 which indicates the amount of pressure or electricity remaining in the tank or battery 274 . The rotary switch 275 may turn the motor on and off and allow the selection of the frequency of the application of the CPR cycles. The selector switch 276 then permits a determination of the force to be applied to the patient. This may also work with feedback along the multichannel cable 269 to maintain the pressure at the preselected value.
[0062] Alternately, the tank 274 may simply hold oxygen that will travel along the cable 269 to the device 201 for delivery to the patient. The controller 270 in this instance includes the on-off and magnitude rotary switch 275 , the pressure controller 276 , and the gauge 273 .
[0063] FIGS. 10 and 12 also show the detachable guide 281 that can releasably attach to the belt ends 225 and 226 of the belt 234 . The guide 281 and each of the ends 225 and 226 may include a mechanism such as hooks and loops to attach them together. The guide 281 provides some stiffness to allow the belt ends 225 and 226 to be forced under the patient and fed into the device 201 . It also provides some additional length for tightening the belt 233 around the patient's chest 212 should that prove necessary.
[0064] FIGS. 10 to 13 also show the clip generally at 285 for holding the belt 233 onto the bar 286 . The Kelly et al. patents and applications suggest hooks and loops for this purpose. This type of connecting device may well perform with complete satisfaction for the anticipated uses of a CPR mechanism. However, the hooks and loops attachment may not prove acceptable under all conditions. Thus, it loses its effectiveness when wet or dirty. Moreover, it can wear out after extensive use.
[0065] The clip 285 avoids these limitations. It includes the curved metal latch 289 which can rotate about its journaled connection 290 to the levers 216 and 220 . Inserting the belt into the clip first involves lifting the latch 289 by turning it in the counterclockwise direction in FIG. 13 and feeding the belt end 226 (possibly with the guide 281 attached) between it and the bar 286 . Locking the belt 233 in place then proceeds by pressing the latch extension 291 in the clockwise direction in that figure. This forces the latch knob 292 to press against the belt 233 and hold it against the bar 286 . Any force that would tend to pull the belt 233 out of the device actually causes the latch knob 292 to push the belt 233 harder against the bar 286 and, by squeezing the belt more tightly, keep it in place for the CPR. Releasing the belt 233 from the latch 285 merely involves lifting the latch end 291 with the fingers and moving it in the counterclockwise direction. This opens the space between the knob 292 and the bar 286 and permits the facile removal of the belt end 226 .
[0066] FIGS. 14 to 16 show the CPR device generally at 301 built on the principles shown in FIG. 6 of the Kelly et al. patents and applications. The base 302 sits upon the patient's chest, and the belt 303 circumnavigates the patient's thorax in the usual fashion. The belt end 307 passes under the rod 308 affixed to the side 309 by the tabs 310 . Similarly, the other belt end 311 passes under a rod held by tabs (all not seen in the figure) to the side 312 . The belt ends 307 and 311 pass onto the stage 315 (in FIGS. 15 and 16 ) where the cap 316 holds them securely in place with the belt snug around the patient's chest.
[0067] The stage 315 and the cap 316 attach to the two rack gears 321 and 322 which have the teeth 323 on both sides. The rack gears 321 and 322 and thus the stage 315 and the cap 316 remain free to move vertically relative to the base 302 and the sides 311 and 312 . Furthermore, The platform 315 attaches to the post 325 which can also move vertically in the housing 326 , which is also attached to the base 302 . The insertion of the post 325 into the housing 326 guides the vertical motion of the stage 315 . As the stage 315 moves upward, it also pulls the belt ends 307 and 311 in the same direction. This pulls the belt ends 307 and 311 through the rods (one of which appears in FIG. 14 and bears the number 308 ) and tightens the belt 303 around the patient's chest for CPR.
[0068] However, the vertical motion of the stage 315 and thus the tightening of the belt 303 fall ultimately under the control of the handles 331 and 332 . The left handle (in the figures) 331 attaches to the two arms 335 and 336 which, in turn, connect to the two gear segments 337 and 338 , respectively.
[0069] Pushing down on the handle 331 will cause the arms 335 and 336 and the gear segments 337 and 338 to rotate in the counterclockwise direction (in the figures) around the rod 341 attached to the sides 309 and 312 by the bolts 343 and 344 , respectively. As the handle 331 and thus the gear segments 337 and 338 rotate in the counterclockwise direction, the teeth on the segments 337 engage the teeth 323 on the left side of the rack gears 321 and 322 causing them to move upwards. This takes the stage 315 and the belt ends 307 and 311 in the same direction which serves to tighten the belt 303 around the patient's chest for CPR.
[0070] Similarly, the handle 352 connects to the two arms 353 and 354 . Pushing down on the handle 352 causes it to rotate in the clockwise direction and move its two gear segments (only the one of which labeled 357 appears in the figures) in the same direction. These, in turn, engage the right side of the rack gears 321 and 322 causing them to move upwards. This helps lift the state 315 and tighten the belt 303 around the patient's chest.
[0071] Thus, pushing down on the handles 331 and 352 accomplishes two tasks. First, it applies a downward force directly from the base 302 onto the patient's chest to depress it. Second, it tightens the belt 303 around the patient's chest to compress it. Both of these actions contribute to the desired CPR.
[0072] The spring 361 sits around the bar 341 and biases the handle 331 in the clockwise direction. If the operator releases the handle 331 after a CPR cycle, the spring 361 will move it back to the upright position seen in the figures. There it will wait for the next cycle.
[0073] FIG. 17 shows a CPR device generally at 401 identical to the unit 301 of FIGS. 14 to 16 . However, it also includes the large suction cup 402 that sits on the patient's chest. Upon the completion of a CPR stroke (as discussed in reference to FIGS. 14 to 16 ), the operator can pull upwards on the handles 303 and 304 . This will cause the suction cup 402 upward and pull the patient's chest in the same direction. This chest expansion assists in the blood flow around the heart and also facilitates the patient's obtaining air for breathing. Instead of the suction cup, the device 410 may have an adhesive on the bottom of its base to accomplish the same objectives.
|
Manual CPR apparatus allowing the application of force at two points separated by a line making a nonperpendicular angle relative to the longitudinal axis of the patient. The line separating the two force points may also lie out of the plane formed by the device's belt which circumnavigates the patient's torso. These geometrical configurations allow the facile application of the CPR force to the device by one or more operators located along the side of the patient. The device may have the capability to limit the achieved circular chest compression to one of a plurality of magnitudes. The device may also provide signals to indicate the appropriate times for applying pressure and may incorporate electrocardiogram and defibrillation components. The device may contact the patient's chest with a suction cup or other adhering component to assist in the patient's chest expanding in the interval between compressive strokes.
| 0
|
FIELD
[0001] The present invention relates to shoe boxes and, in particular, to a shoe box which is configured to maintain each of a pair of shoes in fixed space relation to one another within the box.
BACKGROUND
[0002] Shoeboxes have been designed for shipping and storing a pair of shoes in fixed, space relation to one another. However, as set forth below, these prior designs have a variety of limitations which the present invention overcomes.
[0003] U.S. Pat. Nos. 7,957,192 and 6,951,277 both disclose a shoe box having one or more dividers extending from the end of the shoe box and the dividers extend between a pair of shoes to secure the shoes in fixed, space relation to one another. The divider may be formed from the box blank and may extend out from one end of the box. The shoeboxes may be formed of a die-cut single blank with score lines to fold into the shoebox shape. This particular shoebox divider design does not separate the shoes from the other, but rather maintains the shoes in space relation by folded divider components at the end of the shoes. The limitation of such design, among other things, is that the divider at each end is fixed in size and not well adapted to secure the shoe firmly and in place. Additionally, the divider is prone to rub against the shoe and thereby highly polished shoes may get scuffed or otherwise marred.
[0004] A further limitation of this design is that the dividers are a complex die-cut shape which may require manual handling to secure them in an appropriate position. Also, the shoe dividers are not universally adopted for a wide range of shoes and have to be sized specifically with the particular shoe to be placed in the shoebox.
[0005] A variety of other shoe patents exist which set forth a variety of approaches, none of which solve the problems the Applicant faced and solved with the present invention. For example, Cahill U.S. Pat. No. 1,700,432 discloses a shoe carton in which a divider extends longitudinally along the length of the box, separating it into upper and lower, triangular cross-sections with each triangular cross-section space designed to receive a shoe. The design requires a costly-to-manufacture carton with significant amounts of extra material, provides limited space, and further limits the type of footwear that may be stored inside of the carton.
[0006] The Ferrago U.S. Pat. No. 1,764,251 discloses an unconventional shaped trapezoidal, cross-section box which is difficult to make and impractical to store in today's commercial world. Moreover, the box does not effectively separate the shoes or safeguard the shoes contained in it because they are, in part, in physical contact and susceptible to rubbing against each other.
[0007] The Barnes U.S. Pat. No. 1,781,624 discloses a box in which shoes are positioned side by side with a length-wise extending divider. This box is designed as a more permanent display box and not for use in shipping shoes from a manufacturing facility to a retail facility. It is also difficult and costly to make.
[0008] The Mann U.S. Pat. No. 2,129,501 discloses a shoe box that requires a separate paste-board insert which divides the shoes longitudinally, and thus requires a significant use of additional materials for purposes of separating the shoes one from the other. The design disclosed is, moreover, complex, difficult to manufacture, and assemble which makes its use as a low cost package for shipping shoes impractical.
[0009] The Justin U.S. Pat. No. 2,709,518 discloses a package designed specifically for cowboy boots in which a specially die-cut spacer is provided to fit the boots. This arrangement is time consuming and expensive to assemble and is not readily adapted for a variety of different footwear.
[0010] The Carr U.S. Pat. No. 2,782,978 discloses a complicated shoe box design in which a divider is formed, in part, of multiple, longitudinally extending flaps that fold inwardly. The box does not appear to be capable of being mass produced and cannot be made at costs consistent with today's competitive requirements.
[0011] The Lee U.S. Pat. No. 2,834,460 discloses a collapsible shoe box with dividers that separate the box into compartments. One embodiment of this disclosure relies upon wrapping one shoe in tissue paper to prevent scuffing. A second embodiment illustrated in FIG. 8 uses a longitudinally extending internal divider similar in general to dividers previously discussed which extend from one end of the box to the other and which require significant additional cardboard or pasteboard and involve additional assembly problems.
[0012] The Aull U.S. Pat. No. 2,855,096 primarily features a box which opens at one end and has a mechanism formed integrally with a box for pulling the shoes by the heel from the box as the end is opened. The box has an integrally formed cover with a lip that engages a heel and as the box cover is pivoted open. The lip engages the heel and pulls it outwardly as the cover opens. It also has a divider extending from an end wall that separates one shoe from the other. The divider extends vertically to loosely separate the shoes. It does not provide a wedging action to support the shoes in fixed spaced relation. Nor is it adopted for universal use with footwear that have heels, as well as footwear that have no heels. Additionally, it is a complex design involving use of a great deal of material which is inconsistent with today's cost requirements.
[0013] The Johnson U.S. Pat. No. 3,360,112 discloses a shoe box in which an abutment extends across the bottom of the box for purposes of engaging a shoe heel. The purpose of this is to facilitate the opening of the box for sliding the shoes in and out. It is not primarily directed to a shoe box in which the individual shoes are maintained in fixed, separate relation one to the other since the design permits shoes of a pair to rub against each other.
[0014] The Patterson U.S. Pat. No. 5,193,671 attempts to resolve the problem of shoes rubbing one against the other by providing a pair of boxes that are integrally associated with one another. It does not deal with modifications of conventionally and commercially designed shoe boxes ordinarily used today to solve this problem. The solution suggested by Patterson is not a practical solution for mass produced commercial shoes.
[0015] The Carnahan U.S. Pat. No. 5,590,766 relates primarily to a permanent type of shoe box made of transparent plastic. It suggests the use of an integrally formed shoe tree that apparently support individual shoes. It does not deal with the conventional paperboard or cardboard boxes commercially available and ordinarily used today, nor does it provide a suggestion for improving the function of these shoeboxes to maintain shoes separate one from the other.
[0016] These prior art shoeboxes, designed to hold a pair of shoes in fixed or spaced relation one to the other so that they would not rub against each other, particularly during shipping, do not solve a number of the concerns of shoemakers, dealers, and handlers of footwear. Because shoes can be easily marred or otherwise damaged by rubbing, it is important to keep them separate one from the other. Marring or scuffing of shoes while in transit does, of course, lessen the value and frequently makes the shoes unsaleable. These past efforts to provide a satisfactory solution, however, have not been altogether satisfactory for a variety of reasons in part referred to above.
[0017] The problem is particularly acute now that most footwear sold in the United States is manufactured in foreign countries and is therefore subject to long transit times in which there is ample time for the shoes to rub against one another and be scuffed. While some footwear receives little damage from such scuffing, many of them, particularly suede shoes and high gloss shoes, are particularly susceptible to damage.
SUMMARY OF INVENTION
[0018] The present invention is directed to a commercial shoe box made from conventional shoe box material such as cardboard or pasteboard with multiple sheets of cardboard die-cut and scored in a manner that permits immediate and rapid assembly of the box in a production line in such a manner as to readily receive pairs of shoes or other footwear with individual shoes spaced apart one from the other to prevent scuffing during transportation of the shoes. The present invention provides an inexpensive, easily manufactured shoe box designed with a plurality of dividers that are easily assembled into the shoe box to separate the box into multiple components to receive individual shoes.
[0019] A further object and advantage of the present invention is to provide a shoe box blank which may be inexpensively mass-produced for assembly on-site and adapted for insertion of a variety of different sized pairs of shoes with dividers separating one from the other.
[0020] A further object of the present invention is to provide an improved shoe box design in which the individual shoes of a pair are in a format that may readily be displayed at a point-of-sale in a manner which will permit handling of the box without the likelihood of the shoes scuffling against one another. The present invention also provides a design which allows shipment of a wide range of footwear such as shoes, sandals and the like in a manner that prevents them from being rubbed one against the other.
[0021] A further object of the present invention is to provide an efficient means for packaging shoes in a manner which eliminates the use of shipping paper. Heretofore, shoes are frequently shipped in boxes and are secured in position by stuffing paper in the box. Not only is the stuffing paper in the box expensive because of the costs of the paper, but the paper must be removed before the shoes are displayed at the retail establishment. The present invention eliminates the need for stuffing paper and permits the display of the shoe without the need of additional packaging materials.
[0022] In the present invention, an integral shoe box is assembled with separate dividers that are inserted and secured in one of a series of locations within the shoe box, thus providing a means for securing footwear in the box with the footwear pairs having different sizes.
[0023] The present invention further provides a shoe box having removable dividers in which the dividers, themselves, may be adjusted laterally in the box to accommodate different sized footwear.
[0024] According to one aspect, a shoe box having opposite sides and opposite ends with the sides longer than the ends is provided with a flexible divider extending lengthwise and dividing the box into two longitudinal sections, said divider anchored only at one end to an end wall intermediate its ends and providing separate compartments for each shoe of a pair.
[0025] According to another aspect, a shoebox having opposite sides and opposite ends that are shorter than the sides is provided with a pair of flexible dividers, each divider anchored to a different one of the opposite ends of the shoebox, each divider with a free end positioned and sized to overlap one another at their free ends, whereby the dividers separate the box into two side by side compartments shaped and sized to separately receive one each of a pair of shoes.
[0026] Further novel features and other objects of the present invention will become apparent from a consideration of the following detailed description and claims when taken in conjunction with the drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0027] The foregoing and other objects and advantages of the invention will be appreciated more fully from the following drawings, wherein like reference characters designate like features, in which
[0028] FIG. 1 is a plan view of a prior art shoe box blank before shaping into a box;
[0029] FIG. 2 is a plan view of a die-cut box blank embodying components of the present invention;
[0030] FIG. 3A is a perspective view of a component of the present invention;
[0031] FIG. 3B is a perspective view of the component shown in FIG. 3A with portions folded;
[0032] FIG. 3C is a perspective view of a component of the present invention as shown in FIG. 3 a with portions further folded;
[0033] FIG. 3D is a plan view of the component shown in FIG. 3A fully folded;
[0034] FIG. 3E is a plan view of the folded elements of FIG. 3B with some of the elements slightly displaced; and
[0035] FIG. 4 is a plan view of an assembled shoe box embodying the invention with a pair of shoes shown in dotted outline.
DETAILED DESCRIPTION OF INVENTION
[0036] Although the specific embodiment of the present invention will be described with reference to the drawings, it should be understood that such embodiments are by way of example only and merely illustrate a small number of the potential, specific embodiments which may represent applications of the present invention. Various changes and modifications obvious to one skilled in the art to which the present invention pertains are deemed to be within the spirit and scope of the present invention and further defined and limited by the appended claims.
[0037] FIG. 1 illustrates a typical embodiment of a prior art shoe box blank without a cover. This shoe box has a bottom 10 , sides 12 and 14 , and ends 16 and 18 . The side 14 is secured to the ends 16 and 18 via flaps 30 and 32 which are separated by a score line from side wall 14 with the flaps 30 and 32 each having an interlocking tab 34 and 36 with these interlocking tabs 34 and 36 adapting to interlock, respectively, with tabs 38 and 40 when the side walls 12 and 14 are bent at 90° to the bottom so as to form the bottom of the box. Ends 16 and 18 are also provided with extensions 50 and 52 that extend outwardly and form an interlock element. Interlock portions 50 and 52 are shaped to engage dividers which separate the box into left and right halves not shown in this embodiment as the dividers are separately made to hold a pair of shoes in place.
[0038] The embodiment of FIG. 2 is similar in many respects to the embodiment of FIG. 1 but has further improvements and is simplified to provide the features of the present invention.
[0039] In the embodiment of FIG. 2 , the bottom 60 of the shoe box is divided from sides 62 and 64 by a length-wise score line 66 and 68 . The side walls 64 and 62 are folded along the score line 66 and 68 upwardly in parallel relation to one another to form the shapes of the container portion of the box. The ends of the box are formed by flaps 70 and 72 which are divided from the bottom 60 by score lines 74 and 76 . The ends 72 and 70 are folded upwardly along the score lines 74 , 76 to the shape of the container forming the basic components of the box.
[0040] Flaps 80 , 82 , 84 and 86 are formed in the corners of the die-cut component and are separated from the side wall 62 , 64 by the extensions of score lines 74 and 76 . The end flaps 80 , 82 , 84 and 86 are each formed with a die-cut opening 90 shaped and sized to engage the projecting tab 92 that extends outwardly from the flaps 80 , 82 , 84 and 86 with the tabs 92 engaged with the openings 90 to lock the sidewall and endwalls together.
[0041] In one embodiment, the flaps 80 , 82 , 84 and 86 are engaged on the inner surface of end wall 70 and 72 to provide four exposed slots 100 , 101 , 102 , 103 that extend into the box, and not its outer surface.
[0042] As shown in FIG. 4 , one embodiment of the assembled shoebox has a bottom 60 , two sides 62 , 64 and ends 70 and 72 . It also has folded-in flaps 80 and 82 which folds against flaps 84 and 86 and interlocks with them through the interlock openings 90 and tabs 92 . As assembled, therefore, the open box is configured to receive a pair of footwear. The ends are also provided with four slots 100 , 101 , 102 , 103 at each end. These slots are configured to receive interlocking strips or dividers 110 shown in FIGS. 3A to 3E . These divider 110 are folded into the configuration shown in FIGS. 3D , 3 E and 4 . Divider 110 is folded at a crease line 111 and second parallel crease line 112 , as well as parallel crease lines 113 and 114 to form an enclosed, box-like end. The end flaps of the dividers 110 are secured with the end components interlocked to a slot 120 which engaged the box-like end of a divider 110 when folded over. This arrangement thereby provides an assembly best illustrated in FIG. 4 .
[0043] FIG. 4 illustrates a plan view of a box embodying the invention with a separated pair of shoes shown in dotted outline. The box is shaped as a conventional shoe box with a bottom, two sides, and two ends interconnected to one another to form receptacles to receive the pair of shoes. Flaps 80 , 84 formed at either end as described above include slots 100 , 101 , 102 and 103 at each end. The flaps are formed with slots designed to receive folded end of the flexible divider 110 . As illustrated, the folded divider 110 is formed with creases to form essentially a rectangular shape with a main portion of the divider blank extending into the box generally in the center area. FIG. 4 illustrates a shoebox with two dividers 110 having sufficient length to overlap and touch one another. In one embodiment, each divider 110 is configured to extend across at least approximately one half of the length of the shoebox. In another embodiment, each divider 110 is configured to extend across at least approximately ⅔ of the length of the shoebox. These overlapping dividers 110 separate the shoes one from the other as for purposes previously described.
[0044] As illustrated, in one embodiment, four slots 100 , 101 , 102 and 103 are provided at each end of the box, but more or less can also be provided. The number of slots permit the engagement of the flexible divider 110 at varying positions along the width of the box. In the embodiment illustrated in FIG. 4 , the flexible dividers are offset so that the shoe on the left side has a smaller area to occupy at its toe end than does the other shoe. This is achieved by offsetting the slots one from the other.
[0045] It should be appreciated that various embodiments of the present invention may be formed with one or more of the above-described features. The above aspects and features of the invention may be employed in any suitable combination as the present invention is not limited in this respect. It should also be appreciated that the drawings illustrate various components and features which may be incorporated into various embodiments of the present invention. For simplification, some of the drawings may illustrate more than one optional feature or component. However, the present invention is not limited to the specific embodiments disclosed in the drawings. It should be recognized that the present invention encompasses embodiments which may include only a portion of the components illustrated in any one drawing figure, and/or may also encompass embodiments combining components illustrated in multiple different drawing figures.
[0046] It should be understood that the foregoing description of various embodiments of the invention are intended merely to be illustrative thereof and that other embodiments, modifications, and equivalents of the invention are within the scope of the invention recited in the claims appended hereto.
|
A shoe box having opposite sides and opposite ends with the sides longer than the ends is provided with a flexible divider extending lengthwise and dividing the box into two longitudinal sections, said divider anchored only at one end to an end wall intermediate its ends and providing separate compartments for each shoe of a pair.
| 1
|
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/990,741, filed 9 May 2014.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
MICROFICHE APPENDIX
Not applicable.
DESCRIPTION
1. Field of Technology
At least some embodiments disclosed herein relate, in general, to the field of orthopaedic implant apparatus and systems for bone and joint surgery, and more specifically, to intramedullary fixation apparatus and systems for certain types of fractures, including, but not limited to, fractures of the hip and femur.
2. Background
An open reduction and internal fixation (ORIF) is a type of orthopaedic surgery used to repair fractured bones. This is a two-part surgery. First, the broken bone is reduced or put back into place. Next, an internal fixation device is placed on or in the bone, or both, typically through the use of screws, plates, rods, pins or nails used to hold the broken bone together. The Dynamic Hip Screw and the Gamma Nail are currently two acceptable fixation apparatus to treat unstable intertrochanteric and sub-trochanteric fractures, which are common in the old osteoporotic patient but can be challenging to fix and problematic to manage.
In the 1980s, perhaps the most common method of fixation employed the Dynamic Hip Screw. Typically, there are three (3) components of a Dynamic Hip Screw, including a dynamic lag screw (inserted into the neck of a femur), a side plate, and a plurality of cortical screws (fixated to proximal or distal femoral shaft, or both). The idea behind this design is that the femoral head component is allowed to move along one plane—a Dynamic Hip Screw allows controlled dynamic sliding of the femoral head component along the construct—and since bone responds to dynamic stresses, the native femur may undergo remodeling and proper fracture healing through compression of the fracture line. A disadvantage of this technique, however, was that the plate was lateral to the load-bearing line of the hip, such that any defect in the medial cortex of the femur, whether due to imperfect reduction, comminution, or a metastasis meant that a varus stress would be applied to the fixation with every weight-bearing step, which could, in turn, cause the cutting-out of the screw from the head of the femur, or failure at the nail-plate junction or of the screws securing the plate to the bone.
An intramedullary appliance, the Zickel Nail, addressed some of these problems, but it proved technically difficult to insert, even in experienced hands, and presented its own problems. Among these was the increased likelihood of fracture at the base of the greater trochanter.
The Gamma Nail is also of an intramedullary fixation design, developed for semi-closed insertion. A Gamma Nail has three principle components: an intramedullary rod (nail) passed down the medullary cavity of the upper shaft of the femur, a lag screw passed through a hole in the proximal part of the rod and from there inserted into the head of the femur, and a set screw which prevents rotation of the main screw. The Gamma Nail itself can be somewhat difficult to place, and biomechanical experiments have suggested that while the sliding ability of the lag screw is maintained in the Gamma Nail, it is decreased in comparison with that of the Dynamic Hip Screw. This may be a particular problem in heavy set or obese patients, for whom it may be difficult to obtain access to the trochanter and find an optimal access point for introduction of a lag screw. Moreover, accidental fracture and over-penetration by the lag screw are not uncommon with the Gamma Nail design, and an optimal level of compression of the fractured bone may not always be obtained during surgery.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The embodiments illustrated are by way of example, and not limitation, in the figures of the accompanying drawings in which like references indicate similar elements.
FIG. 1 is an isometric view of an intramedullary nail, a dynamic lag screw structure comprised of a longitudinal sheath and a lag screw, and a surgical screw as a fixation means.
FIG. 2 is cutaway view of a dynamic lag screw structure with a lag screw inserted fully into a longitudinal sheath, revealing a dynamic channel for introduction of an intramedullary nail through the dynamic lag screw structure.
FIG. 3 is an isometric view of a femur, the head and neck of which have been reamed to accept a dynamic lag screw structure, with the longitudinal sheath thereof in position for insertion.
FIG. 4 is an isometric view of a femur into which the longitudinal sheath of a dynamic lag screw structure has been inserted, and the lag screw of the dynamic lag screw structure is in position for insertion within the sheath and thence into the neck and head of the femur.
FIG. 5 is an isometric view of a femur, reamed for placement of an intramedullary nail through a dynamic lag screw structure via a dynamic channel created by the alignment of an upper orifice and a lower orifice of a longitudinal sheath with a slot in a lag screw.
FIG. 6 is an isometric view of a femur into which an intramedullary nail has been inserted through the dynamic lag screw structure, and of a surgical screw in position to be installed distally as a fixation means to secure the intramedullary nail in position with respect to the femur.
FIG. 7 is an isometric view of a femur into which an intramedullary nail has been inserted through the dynamic lag screw structure, and into which a surgical screw has been inserted distally through a lateral orifice in the intramedullary nail.
FIG. 8 is a cross-sectional view of an intramedullary nail that has been inserted into the medullary shaft of a femur through the dynamic lag screw structure, revealing an external lip of a lag screw engaged with the inner lip of a longitudinal sheath, and the external rim of a longitudinal sheath engaged against the lateral cortex of the femur.
DETAILED DESCRIPTION OF THE INVENTION
The following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the description. References to “one embodiment” or “an embodiment” in the present disclosure are not necessarily references to the same embodiment; and, such references mean at least one.
Reference in 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 disclosure. The appearances of the phrase “in one embodiment” or substantially similar phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not other embodiments.
As illustrated in FIG. 1 , an embodiment of the system comprises an intramedullary nail (intramedullary rod) 101 , a dynamic lag screw structure 102 including a longitudinal sheath 103 open at a distal end 116 and at a proximal end 117 with an upper orifice 109 and lower orifice 110 , and further including a lag screw 104 with a longitudinal slot, configured to be inserted into the proximal end of the longitudinal sheath, and may further have some securing means known in the art, such as surgical screws, bolts, or tightrope fixation, configured to keep an intramedullary nail 101 in a proper position relative to a bone. By way of illustration and without limitation, in an embodiment, an intramedullary nail 101 may have one or more lateral orifices 105 passing through it proximally or distally, or both, with respect to a long bone, each such lateral orifice 105 configured to accept one or more surgical screws 106 configured to pass into or through an intramedullary nail 101 . As is known in the art, an intramedullary nail 101 may have a solid, semi-solid, or hollow core, may be curved to accommodate the anterior curvature of a femur of a patient, and may be of varying length and proximal and distal diameter, as may be appropriate to a given patient. An intramedullary nail 101 may be tapered at its distal end 107 , inter alia, to facilitate insertion, and may be configured at its proximal end 108 to receive a guidance device or comparable instrument known in the art.
In an embodiment, a longitudinal sheath 103 of a dynamic lag screw structure 102 is open at a distal end 116 and at a proximal end 117 , with an upper orifice 109 and lower orifice 110 , said upper orifice 109 and lower orifice 110 together configured to accept an intramedullary nail 101 and allowing at least a portion of said intramedullary nail 101 to be passed transversely through said longitudinal sheath 103 . In an embodiment, the distal end (insertion end) 116 of a longitudinal sheath 103 may be tapered, may have an outer rim at its proximal end 117 , and may have an inner lip 119 . An outer rim 118 may be configured to ensure that a longitudinal sheath 103 cannot be inserted beyond the lateral cortex of a femur. In an embodiment, a longitudinal sheath 103 may be pressed or tapped into the bone through a hole or channel that has been reamed in a bone.
In an embodiment, a lag screw 104 may employ at its distal end (insertion end) a self-tapping thread 111 . In an embodiment, a lag screw 104 may have at its proximal end a drive 112 . Said drive 112 may include some form of internal threading 113 or other securing means configured to receive a self-holding screwdriver or comparable tool known in the art. In an embodiment, a lag screw 104 may have longitudinal slot 114 through its shank 115 configured to accept an intramedullary nail 101 and allowing at least a portion of it to pass through said lag screw 104 . In an embodiment, a lag screw 104 may have an external lip 120 at its proximal end configured to engage an inner lip 119 of a longitudinal sheath 103 so as to prevent said lag screw 104 from further penetrating the bone.
As illustrated in FIG. 2 , in an embodiment, a lag screw 104 may be inserted into the proximal end of a longitudinal sheath 103 , and at least a portion of an intramedullary nail 101 passed through a dynamic channel formed by the alignment of both an upper orifice 109 and a lower orifice 110 of said longitudinal sheath 103 with a longitudinal slot 114 in the shank 115 of an inserted lag screw 104 —said dynamic channel configured to allow movement of said lag screw relative to said intramedullary nail 101 following surgery—and thence into the medullary shaft of a femur. Such a dynamic lag screw structure 102 or comparable structure may be configured to allow the dynamic adjustment of the position of the lag screw 104 in three dimensions—longitudinally, laterally, and normally (i.e., vertically)—relative to the intramedullary nail 101 , and hence, to the shaft of the femur and to the neck and head of the femur, respectively, permitting further compression of the fractured bone as a patient begins to bear weight on the joint following surgery.
An embodiment may be comprised of various types of stainless steel, titanium, titanium alloys, biodegradables and other suitable materials, alone or in combination, known in the art.
An embodiment of the current invention allows it to be placed in the hip simply and quickly using an external guidance device or system. Such an initial placement may be thought of as similar to the placement of a screw for in-situ pinning.
As illustrated in FIG. 3 and FIG. 4 , the neck 301 and head 302 of a femur 303 then may be reamed in a two-step process. First, a channel may be reamed at a desired angle from the lateral cortex of the fractured proximal femur to the center of the head of the fractured proximal femur at the desired depth for the lag screw previously determined. Second, a wider and shorter channel may be reamed at approximately the same angle to accommodate a longitudinal sheath 103 . Next, a longitudinal sheath 103 may be pressed or tapped into the bone until any external rim of the sheath reaches the lateral cortex of the fractured proximal femur.
As illustrated in FIG. 3 and FIG. 4 , the neck 301 and head 302 of a femur 303 then may be reamed in a two-step process. First, a channel may be reamed at a desired angle from the lateral cortex of the fractured proximal femur to the center of the head of the fractured proximal femur at the desired depth for the lag screw previously determined. Second, a wider and shorter channel may be reamed at approximately the same angle to accommodate a longitudinal sheath 103 . Next, a longitudinal sheath 103 may be pressed or tapped into the bone until any external rim of the sheath reaches the lateral cortex of the fractured proximal femur.
As illustrated in FIG. 4 and FIG. 5 , a lag screw 104 , which may have been attached to a self-holding screwdriver or comparable device, may then be inserted into and through the longitudinal sheath 103 embedded in the bone and screwed or otherwise inserted into the neck and head of a femur and into the longer, narrower channel initially reamed. As illustrated in FIG. 6 , an upper orifice 109 and a lower orifice 110 in a longitudinal sheath 103 and a slot 114 in a lag screw 104 which has been inserted into a longitudinal sheath 103 may aligned, and the resulting dynamic channel for introduction of an intramedullary nail 101 lined up with the medullary canal of a femoral shaft. A fluoroscope or other guidance device or system then may be used to place an intramedullary nail 101 through the trochanter into the construct and canal of a femur. As depicted in FIG. 6 , FIG. 7 and FIG. 8 , an intramedullary nail 101 then may be secured to the bone with one or more surgical screws 106 utilizing a fluoroscope or other guidance device or system.
In the foregoing specification, the disclosure has been described with reference to specific exemplary embodiments thereof. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.
|
An orthopedic intramedullary fixation apparatus and system for use in hip and femur fracture surgery comprises an intramedullary nail, a dynamic lag screw structure comprising a longitudinal sheath and a lag screw, and securing means to fix the intramedullary nail relative to a femur. A dynamic channel created by the lag screw structure allows the lag screw to adjust dynamically, and thereby may permit further compression of the fractured bone to an optimal level as a patient begins to bear weight on it following surgery. Surgical fixation may be expedited, as a favorable point of access for a lag screw may be determined readily, particularly with obese patients in whom access to the trochanter may be problematic. Complications during surgery, such as accidental fracturing of the femoral neck and head and over-penetration of the lag screw may be avoided.
| 0
|
FIELD OF THE INVENTION
[0001] The invention relates to design of integrated circuits and to end-product integrated circuits.
PRIOR ART DISCUSSION
[0002] FIG. 1 shows a typical integrated circuit 112 at a high level. The chip 112 contains an internal logic core 110 , an I/O ring 114 , and pins 116 . FIG. 2 shows the logic interfaces between the core 110 and a single chip pin 116 . The chip pin 116 is connected physically to an I/O cell 400 ( FIG. 3 ), which fulfills a wide range of requirements for connecting to the environment external to the chip in a correct manner. This I/O cell 400 has a chip side interface 222 that can be used to control the I/O cell and may range from a simple output signal to a full suite of control capability including characteristics such as timing, slew-rate, output drive, pull-up/pull-down, and power. On the chip core 110 side the interfaces to I/O logic can include core signals that can be selected as device pins 218 , control for Boundary Scan circuitry and registers (BSRs, FIG. 4 ) 219 and control for the I/O cell itself 220 . There may also be two modes for these interfaces 218 , one that controls the chip in a normal fashion also called functional mode or one that controls the I/O cell to perform tests, also called test mode. While this is a generic representation of a chip pin, it may be shared in a number of ways with other pin logic. For example, a core input pin may be sourced from multiple pins and thus may need to be multiplexed with multiple core inputs 224 .
[0003] While integrated circuit functional complexity keeps growing, the number of I/O pins on a package hasn't been keeping pace, and the complexity of the I/O ring has had to compensate. Many chip manufacturers are resolving multiple-application requirements into single chip solutions and are giving their customers a menu of chip interfaces to choose from. Increasing gate density allows more functionality to be implemented in these devices and the number of available pins imposes limitations.
[0004] Next generation I/O requirements are leading us away from the traditional perspective of an I/O ring with a few hundred silicon gates to a complex and interdependent “I/O fabric” with requirements driven from many hardware design disciplines. Traditionally, in integrated circuit chip design, the I/O ring was a top-level component within which all I/O related logic was instantiated. Typical components included I/O cells, boundary scan registers (BSRs), some minor pin multiplexing and other glue-logic type of functionality. Indeed, the I/O integration task is on the critical path of many chip designs. With increasing I/O layer complexity, device pins are heavily bound within a pin-limited package. There is extensive sharing of pins for functional and test purposes. With this growing complexity, the I/O ring is evolving into an I/O fabric that needs to allow full utilization of pin resources and balance constraints from a multitude of sources including functional, DFT, timing, power, die and package constraints.
[0005] A device pin is a physically limited resource. While it really can only be one thing at one time, in a chip with multiple applications, it may have different functions. The pin may also need to be utilized by test equipment to gain access to the internal test infrastructure. The internal chip core functions may require two to four times the number of available device pins leading, to complex many-to-many multiplexing scenarios. As a consequence, a single device pin may have several functional modes as well as several test modes, all with their own timing and power requirements. To overcome this limitation the I/O fabric has to be highly configurable. The configuration scheme has to be balanced to ensure that the selection of one interface can co-exist with several others and this leads to some interfaces having sets of I/O pins in different configurations. This many-to-many I/O mapping leads to I/O pins having several system functions and several test functions. Some approaches exist in the industry which use time-division multiplexing to reduce the number of pins between devices, but where chips need to connect to specific devices, this approach is not satisfactory. With pin-sharing, it may be that different pins have different timing requirements.
[0006] All device pins require I/O circuitry, typically known as an I/O cell, which drive signals out of the chip or inputs into the chip. I/O cells typically have directional attributes so they can be input, output or bidirectional. There may be other types of functionality e.g. open collector, analog etc. I/O cells themselves are becoming more complex and therefore require more fine grained control to account for process, voltage and temperature variation in the manufacturing process and operating conditions of the device. The complexity of the I/O cells are increasing in order to take into account specific control requirements such as pull-up/pull-down (PUPD), Load Control/Slew rate, Input Enable, Wakeup, output current strength, bus hold and signal termination control. Each of these I/O cell control functions requires the insertion of specialized control logic per pin into the I/O Fabric. Serial interface protocols also play a part in additional complexity such as Utopia IV, SPI-4.2, SFI-4, and 10 Gigabit Ethernet. Different types of I/O cells such as multi-pad I/O cells, Analog I/O, low-voltage differential signaling (LVDS), Double Data Rate (DDR) I/O cells have emerged to handle these various interface protocol requirements. These requirements have increased the complexity of the I/O cells significantly and thus the control logic needed for these I/O Cells. FIG. 3 shows a typical bidirectional I/O cell 400 with an output 412 , and an output enable 414 which are used to drive the output onto the device pin 116 . The value on the device pin can also be used as an input to the chip and driven as a core input 416 . This I/O cell also has pull-up/pull-down control 410 which can be used to enable pull-up/pull-down resistors internal to the I/O cell. There may be additional control signals 418 to control such things as power and slew rate.
[0007] To comply with complex DFT (Design for Test) requirements, additional logic needs to be added to chips in order to ensure that they can be properly tested. This results in additional logic being added to the I/O fabric in the form of test multiplexing, Boundary Scan (BSR) logic and test logic to implement testing. The boundary scan chain logic provides a mechanism to test interconnects between and within integrated circuits without using physical test probes. FIG. 4 shows a typical BSR Cell. Essentially, a BSR cell it inserted across a pin data path. On an output path a core pin destined for an I/O cell is connected between the BSR's data_in 510 and data_out 512 . In normal mode of operation, data_out is equal to data_in. However in test mode (setting mode 514 to 1) the data_out can be driven from a hold register which can be set at a specific value by test circuitry using a BSR scan chain. By controlling BSR cells inserted on outputs and output enables, the actual I/O cell functionality or even circuitry external to the chip can be tested. A BSR cell can also be inserted on the input path and allow control and observability of input pins. BSRs may also be put on I/O Cells control paths 418 .
[0008] For functional requirements, the multiplexer logic generated for a given device pin needs to take into account timing sensitive signals and logic.
[0009] For power requirements, power-sensitive devices are becoming much more prevalent. Power sensitive devices have increasingly granular power islands which can be turned off in order to conserve power. In a power-sensitive device the physical view of the system is very different to the functional view and this can seriously impact the chip infrastructure as low power design techniques require rethinking of the entire IC design flow. Power reduction and I/O cell power optimization is a key target within most SoC design methodologies. Power optimization can result in the transposing of another layer of logic and control within the I/O cell, and correspondingly the I/O ring, including the insertion of power isolation cells and voltage level shifters.
[0010] When considering that the granular multiplex and control circuitry for a single chip pin may be extensive, the problem is exacerbated when there are hundreds or thousands of pins and where the requirements may change frequently. Prior approaches to integrated circuit design have involved manually coding the specific logic required for each pin and potentially sharing functional and test logic implementation between several teams. Manual coding of incrementally changing I/O requirements leads to poorer design quality and high consumption of design resources to design and verify the I/O ring. Also the turn-around time between a requirements (specification) change and a resulting change in the I/O ring implementation (circuitry) could be excessive.
[0011] Generally, many prior pin-sharing approaches focus on the switching mechanism that decides who gets control of the resource. The switching mechanism can either be done on time cycle (TDM), or by some level of handshaking between two chips but this would mean that both chips need to be designed with this mechanism in mind. This falls down however when a chip has to be connected to different devices that may not be aware of any pin sharing protocols.
Objectives
[0012] The invention is directed towards achieving improved integrated circuit design and improved I/O rings to address at least some of the above problems. Objectives include:
generation of an I/O layer that can be derived from a single-source specification which can handle a large range of I/O requirements; and/or achieving a higher level of design automation; and/or improved coherency or design-rule checks on the specification that ensures that the specification is correct and the generated implementation will also be correct-by-construction, achieving fewer bugs, less verification, and less corresponding delay.
SUMMARY OF THE INVENTION
[0016] The invention achieves at least some of the above objectives by capturing, in an automated tool, an extensive range of I/O requirements in a generic fashion and automating design of an I/O layer.
[0017] The invention provides a method of generating a design for an I/O fabric of a target integrated circuit having a core and pins, the method being performed by a programmed computer operating as a process tool executing algorithms to generate a synthesizable representation of the I/O fabric ring in hardware description language. The method comprises the steps of:
importing integrated circuit design data, from said design data, capturing I/O specification data for the core, cells, pins, I/O control, BSR and I/O cell chaining, and die for the target integrated circuit. validating said specification data, and from said validated specification data, generating the I/O fabric design.
[0022] The latter is achieved in a preferred embodiment by synthesizing, configuring and inter-connecting multiplexers in a cascaded arrangement according to constraints for signal control and timing, wherein a control matrix structure is realized for each pin on both the input and output paths for the following logic types:
a functional multiplexer matrix structure, a test multiplexer matrix structure, an override matrix structure, a multiplex select and control matrix structure, and I/O cell control logic.
[0028] In one embodiment, a required pin input and output path logic is configured by modification of the I/O specification data, and/or modification of a manner of wiring of the algorithms, and/or by modification of the algorithms.
[0029] In one embodiment, the tool wires algorithms according to a wiring framework, and said wiring framework is modified.
[0030] In one embodiment, the output path for a chip pin is sourced during the method from any number (1 . . . n) of functional or test core pins, there being different pin functional or test modes for at least some different sources and comprising the step of dynamically selecting a functional or test core pin for an output pin, wherein the selection for a given logic type controls an individual chip pin, a group of related pins or globally all chip pins.
[0031] The output path of a chip pin may be dynamically controlled during the process from any number of pin (0 . . . n) output overrides, in which an override is enabled by a Boolean logical equation of signals existing within the chip.
[0032] In one embodiment, the method applies control by setting values in the override matrix structures comprising any or all of:
forcing a value on an output pin, including controlling pull-up/pull down logic, allowing an override to output a pin logical value or the value of any signal within the chip, allowing an override to have the ability to control the output enable of an I/O cell, forcing logic into a test mode, forcing logic into a functional mode, an override having an inherent priority in which one override can override another, and/or allowing a priority to be specified by a user.
[0040] In one embodiment, the method comprises performing timing optimisation for functional or test output path multiplexer logic, in which for each chip pin a priority ordering of input signals to the multiplexer is created to determine timing priority through said multiplexer.
[0041] Preferably, control priority of a given logic type in the I/O fabric is configurable.
[0042] In one embodiment, the tool's default configuration is that overrides have precedence over test multiplexing, which has precedence over functional multiplexing.
[0043] In one embodiment, timing priority of a given logic type in the I/O fabric is configurable, and the tool's default configuration is that functional multiplexing has precedence over test multiplexing, which has precedence over overrides.
[0044] In one embodiment, the method comprises generating a behavioral description of a multiplexer, and combining said multiplexer behavioral descriptions in a cascade of logic to provide the I/O fabric design.
[0045] In another embodiment, the method comprises the steps of automatically replacing the generated behavioral description with a structural multiplexer cell instance from a library, extracting conditional statements from the behavioral multiplexer description and assigning them a numeric vector based on their priority, and using said numeric vectors to select the input logic signal which will be driven on the output of the structural multiplexer cell.
[0046] In one embodiment, in the method:
required pin input circuitry is configurable, a core input is a functional or test core pin, a core input is sourced from multiple chip pins, each having an associated prioritization, and each having an associated selection control signal, a core input is dynamically controlled from any number of prioritized pin (0 . . . n) input overrides, wherein an override can be enabled by any logical equation of signals existing within the integrated circuit including: forcing a logical or signal value on a core input pin, and a core input pin is protected if no chip pin or input override is selected, wherein the protection value is either a logical value, a signal value, or a chip pin when the core pin is only assigned to a single chip pin.
[0052] In one embodiment, the prioritization of the chip pins multiplexed on a core pin input path is determined based on logic type, with the lowest mode number within the logic type taking precedence, and if the input core pin is in the same mode for the logic type on different chip pins then the highest ordered chip pin will take precedence.
[0053] In one embodiment, the logic of the I/O fabric is tagged according to power domains, and thus the inputs and outputs of the multiplexers have an associated power domain, and multiplexers are fragmented on the basis of the power domains.
[0054] In one embodiment, in the method:
the logic of the I/O fabric is tagged according to power domains, and thus the inputs and outputs of the multiplexers have an associated power domain, the output path core pin multiplexers whose input signals have different domain references are fragmented into two stages, a new multiplexer is created in a first stage per unique domain reference which has more than one input signal belonging to it, the outputs of the first stage are multiplexed into a second stage along with the output from any preceding logic in the cascade of logic, and the combination of multiplexer logic fragments is logically equivalent to the original un-fragmented multiplexer.
[0060] In one embodiment, I/O control override equations are used to control and configure the I/O cell used by a chip pin, equation definitions are re-used by substitution of dynamic information, and the resulting logic, when equivalent, is shared by multiple I/O cell control ports.
[0061] In one embodiment, the tool generates the behavioural description for test or functional output signal multiplexer logic by performing the steps of:
creating the output multiplexer and setting the default value of the multiplexer to LOW, for each of a plurality of pin modes, either functional or test, sorting in order of priority: and if the pin's mode has core pin output then selecting the core pin output signal when the control signal for the logic type equals the current mode, and if the pin has preceding logic in the cascade of multiplexers then ensuring that an output enable signal for preceding logic is not enabled, and if a pin has preceding logic in the cascade of multiplexers then selecting its output value when the output enable signal for this logic is enabled,
[0064] In one embodiment, the tool generates the behavioural description for test or functional output enable signal multiplexer logic by performing the steps of:
creating the output enable multiplexer and setting the default value of the multiplexer to OUT_OFF, for each of a plurality of pin modes, either functional or test, sorting in order of priority:
if the pin's mode has core pin output but the core pin's output enable (OE) signal's polarity is not equal to the I/O cell's OE polarity then invert the core pin OE signal's polarity, if the pin's mode has core pin output and the core pin has an OE signal then selecting the core pin's OE signal when the control signal for the logic type equals the current mode, and if the pin has preceding logic in the cascade of multiplexers then ensure that the OE enable signal for preceding logic is not enabled, if the pin's mode has core pin output and the core pin does not have an OE signal then selecting OUT_ON when the control signal for the logic type equals the current mode, and if the pin has preceding logic in the cascade of multiplexers then ensure that the OE enable signal for the preceding logic is not enabled, and if the pin's mode has core pin input then selecting OUT_OFF when the control signal for the logic type equals the current mode, and if the pin has preceding logic in the cascade of multiplexers then ensure that the OE enable signal for the preceding logic is not enabled,
if a pin has preceding logic in the cascade of multiplexers then select its OE value when the OE enable signal for this logic is enabled,
[0072] In one embodiment, the tool generates the behavioural description for an enable signal selection multiplexer by performing the steps of:
creating the enable signal selection multiplexer and setting the default value of the multiplexer to disabled, for each of a plurality of pin modes, either functional or test, sorting in order of priority:
if the pin's mode has core pin output then selecting enabled when the control signal for the logic type equals the current mode, and
if the pin has preceding logic in the cascade of multiplexers then selecting enabled when the logic enable signal for the preceding logic is enabled.
[0077] In one embodiment, the tool generates the behavioural description for input override multiplexer logic by performing the steps of:
creating an input override multiplexer and setting the default value of the multiplexer to LOW, for each of a plurality of core pin input overrides, sorting in order of priority:
if the input override type is ONE then selecting a HIGH override value when the override enable control signal is enabled, if input override type is ZERO then selecting a LOW override value when the override enable control signal is enabled, and if input override type is signal, selecting override drive signal override value when override enable control signal is enabled.
[0083] In one embodiment, the tool generates the behavioural description for input multiplexer logic by performing the steps of:
creating an input multiplexer and setting the default value of the multiplexer to be the core pin's input protection value, for each of a plurality of functional modes and then for each of a plurality of chip pins:
if a core pin is multiplexed in the functional mode then selecting the chip pin when the current chip pin's functional control signal equals the current functional mode, and for each of a plurality of test modes if the current chip pin has multiplexing in the current testmodes on the current chip pin, then ensure that the chip pin's test control is not equal to the current test mode, and
for each of a plurality of test modes and then for each of a plurality of chip pins:
if a core pin is multiplexed in the current test mode then selecting the current chip pin when the current chip pin's test control signal equals the current test mode.
[0090] In another aspect, the invention provides a computer readable medium having a computer readable program code embodied thereon, said code being adapted to implement, when executing on a digital processor, the steps of a method as defined above in any embodiment.
[0091] In a further aspect, the invention provides a data processing system comprising a digital processor, memory, a storage device, and input and output interfaces and the processor being adapted to perform a method as defined above in any embodiment
[0092] In a still further aspect, the invention provides an integrated circuit having a core and pins and an I/O fabric with multiplexers, wherein there is different logic on pin output paths and pin input paths, there is a cascaded multiplexer arrangement to achieve control priority and timing priority for functional, test and override logic types: wherein the multiplexer arrangement provides:
maximum control priority for override logic signals, second highest control priority for test logic signals, lowest control priority for functional logic signals, maximum timing priority, having the shortest path, for the functional logic signals, second highest timing priority for the test logic signals, and lowest timing priority for the override logic signals.
[0099] In one embodiment, the multiplexer arrangement for each logic type in the overall cascaded multiplexer arrangement is implemented in first and second multiplexer stages, wherein:
the first multiplexer stage comprises solely of the logic signals for the logic type, the second multiplexer stage combines the output of the first stage with the output of the preceding logic type, where the preceding logic type is so defined based on timing priority, and the order of prioritization of signals into the second stage multiplexer is based on priority of control.
DESCRIPTION OF THE INVENTION
Brief Description of the Drawings
[0103] The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:—
[0104] FIGS. 1 , 2 , 3 and 4 are diagrams representing the prior art, as discussed above;
[0105] FIG. 5 is a flow diagram illustrating at a high level operation of a tool for importing IC requirement documents, allowing the user to capture additional I/O specification information and to generate an I/O fabric design with a high level of automation;
[0106] FIGS. 6 , 7 and 8 are high level view of a generic pin muxing structure part of an I/O ring developed by the tool, including both input and output multiplexing (“muxing”);
[0107] FIG. 9 is a circuit diagram showing the preferred embodiment of the mux arrangements for delivering output and output enable logic to an I/O cell;
[0108] FIG. 10 is circuit diagram showing the type of IO Control Override logic which can be placed on IO Cell control signals.
[0109] FIGS. 11 and 12 are diagrams showing multiplexing arrangements for fragmentation of multiplexer circuitry according to power partitioning in the core;
[0110] FIG. 13 shows multiplexing arrangements when structural multiplexer cells which contain transistor logic are used in place of RTL multiplex logic automatically generated by the design tool of the invention;
[0111] FIG. 14 shows an alternative embodiment of multiplexer arrangements for delivering output and output enable logic to an I/O cell; and
[0112] FIG. 15 shows how a wiring engine resolves dependencies between different contributors which need to be executed in order to construct logic.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Overview of Process
[0113] Referring to FIG. 5 a tool “spinner” 601 captures 608 from imported documents 604 and user input an I/O specification 609 including a core specification; library of cells; pin specification; I/O control specification; BSR and I/O cell chaining specifications; and die and package specification. The I/O specification can be captured directly by a user in the tool ‘spinner’ 601 or imported from external sources. There may be various sources 604 of information e.g. HDL (VHDL or Verilog™) files describing I/O cells, or Excel™ sheets having pin multiplexing information. The tool validates 610 the specification 609 for coherency and generates 612 a design for an I/O fabric 625 of a chip 620 . The tool not only generates the I/O fabric (or “ring”) 625 but also the chip 620 top-level design and hook-up to the internals of the chip core 626 .
[0114] The core specification involves describing the core pins which are available to be multiplexed in functional and test modes. A core pin is designated as being either a functional or test core pin. The signal paths supported by the core pin are described along with the type and polarity of any associated output enable. Each core pin is assigned a protection value, a set of prioritized input overrides and a domain property. As part of the generation step the tool ‘spinner’ will automatically infer all necessary control signals on the core interface however users can also capture these directly if desired.
[0115] The library of cells contains the interface description for I/O, BSR and Structural Mux cells used in the I/O Fabric. The interface ports of the cells are annotated with a function property so that the tool ‘spinner’ 601 understands how they should be connected. Other cell specific properties can also be captured for example the Joint Test Action Groups (JTAG) Boundary Scan definition language (BSDL) cell type of a Boundary Scan Register (BSR) cell.
[0116] For a given pin 116 a user defines the I/O cell 400 to use, the core pins 218 multiplexed in functional and test modes, the priority of functional and test modes per pin; the granularity of control needed for test and functional multiplexing and the prioritized set of output overrides. Users can define three domain properties per chip pin which determines which domain each type of logic created for a given chip pin is grouped in. Users and also specify whether a structural multiplexer cell should be utilized for a given logic type.
[0117] The I/O control specification allows a user for all the ports into and out of the I/O Cells for all the pins to define if a BSR cell 226 should be instantiated and the I/O control override equation to use on control ports 418 . For the I/O control override equation 419 users can specify the location where the logic should be created and whether a structural multiplexer cell should be utilized.
[0118] The BSR and I/O cell chaining specifications allow the user to decide how many chains of a given type should be created and the pins 116 which will be a member of the chain. The chaining order of the pins which are a member of a chain is normally defined by the die pad ordering in the die specification. Each chain definition captures the type of chain; the start pin for the chain; the scan in port for the chain; the scan out port for the chain. A BSR chain also requires that a chain select signal be defined and the JTAG control (TDI, TDO, TMS, TCK, NTRST, RTCK) interface be specified.
[0119] For each die pad an associated pin 116 must be assigned. The die pads are assigned geometrical coordinates so that their location on the chip's die can be determined. The die pad ordering used to construct BSR and I/O cell chains needs a direction to be defined (clockwise or anti-clockwise) so that the order of the pins can be determined. Additional backend flow related properties can be defined for die pads. Additional specialized die pads (power, filler, spacer and corner pads) which do not affect the generated I/O Fabric can also be defined. The tool ‘spinner’ supports the capturing of package related information but this does not affect the type of I/O Fabric 625 which will be generated.
[0120] The method performed by the tool generically specifies I/O requirements and generates optimised multiplexing and control circuitry for each of the chip pins on a device. The I/O logic can be fragmented into granular blocks of control logic and regrouped into a new hierarchy in order to facilitate the creation of power domain islands and thus the power partitioning of the chip's logic.
Designs Generated by the Process
[0121] Referring to FIGS. 6 , 7 , and 8 a set of functional core and test core pins can be selected for multiplexing on a device pin. FIG. 6 shows a generic output pin mux structure 700 generated by the tool. It is represented in the tool as a set of matrices, namely a multiplex select and control mux matrix 730 , a functional mux matrix 715 , a test mux matrix 717 , and an output override matrix 724 .
[0122] The term “core pin” is an abstraction which refers to three types of signals on the core interface, namely output 710 / 716 , output enable 712 / 718 , and input 752 signals. These three signal paths are referred to as a core pin when they relate to the same functional or test logic inside the core. The table below shows some different types of core pins which are generated:
[0000]
Core Pin Type
Comprised of
Bi-direction with output enable
Output 710/716, output enable 712/718, and input 752 signals.
This is a bi-directional core pin with an output enable.
Bi-direction with shared output
Output 710/716, output enable 712/718, and input 752 signals.
enable
An output enable 712/718 signal for this type of core pin is
shared by a set of related core pins whose output enable needs
to be toggled simultaneously.
Output with output enable
Output 710/716, output enable 712/718.
This type of core pin does not have an input path.
Output with shared output
Output 710/716, output enable 712/718.
enable
This type of core pin does not have an input path. The output
enable 712/718 signal is shared by a set of related core pins
whose output enable needs to be toggled simultaneously.
Output with no output enable
Output 710/716.
This type of core pin does not have an output enable.
Input
Input 752
This type of core pin only has an input path.
[0123] The polarity of the Output Enable 710 / 716 signal can be either active high or active low. Multiplex select and control logic 730 will automatically align to the polarity of an output enable 733 required by the I/O Cell.
[0124] As described in the table above it is optional as to whether a core pin is comprised of an output enable signal. If it is multiplexed onto a device pin whose I/O Cell requires an output enable then the multiplex select and control logic 730 will provide logic to turn the output enable ON when this core pin is selected in either the functional or test matrix.
[0125] Each device pin has an associated functional 714 and test 720 multiplex selection signal. Collectively, these two signals can be referred to as the device pin configuration signals and are used to configure the multiplex mode of operation of the device pin. The functional mux selection signal 714 determines which functional core pin is selected. Likewise, the test selection signal 720 determines which test core pin is selected. These selection signals can come from the core interface or can be generated from user-specified logic inside the I/O ring 625 . The selection mechanism is configurable whereby the functional 714 and test 720 multiplex selection signals can either be global, where signals which affect all device pins; grouped which affect a subset of the device pins or individual which affects each device pin independently. The functional and test selection signals ( 714 / 720 ) are optional in cases where the device pin is dedicated and only has a single functional or test core pin multiplexed.
[0126] The set of device pin configurations can be referred to as the overall chip configuration. By configuring each device pin using the mux selection signals one can determine the overall configuration of the device.
[0127] A key aspect of this invention is the configuration and generation of a flexible multiplexing and control structure which implements multiplexing of N-N functional or test core pins. This results in multiplexing and control logic on pin output and input paths. FIG. 6 shows such a structure for the output path for a given device pin. The multiplexing is N-N because a single device pin can have multiple core pins multiplexed; likewise a single core pin can be multiplexed onto multiple device pins. The output path for each device pin is made up of a pair of signals namely the output signal 710 / 716 and an associated output enable 712 / 718 signal. While the output enable 712 / 718 signal is not mandatory, the output enable signal going to the I/O cells 733 may be required, so control logic is generated when necessary. An output enable 712 / 718 signal can be shared by a group of core output pins. The polarity of the output enable 712 / 718 signal can be different for each of the core output signals which are multiplexed. The multiplexer selection 714 / 720 signals are used to determine which input into the multiplexer is selected. Separate control logic 814 / 820 needs to be generated for the output and output enable paths for both functional 715 and test 717 paths.
[0128] In FIG. 6 , the functional 715 , test 717 and override 724 logic are all shown at the same level or order in relation to the multiplex select and control logic 730 . It is described below how the multiplex select and control logic 730 can be constructed such that the user can choose a priority of control and timing priority for the three logic types 715 / 717 / 724 .
[0129] A further level of timing layout optimisation is provided for the functional 715 and test 717 multiplexer logic. For each device pin the user can select the priority ordering of the input signals 710 / 712 / 716 / 718 to the multiplexer and therefore choose exactly the timing layout through this multiplexer.
[0130] FIG. 7 shows the override logic which is provided on the output path. An override allows the output of a device pin to be forced to a defined value when desired. This allows the inclusion of any number of device pin overrides 724 of a wide range of types of override control. Thus, each device pin can have zero or more overrides which can be used to control the output of a device pin. There are multiple different overrides which can be assigned which affect not only the device pin's I/O cell's output 732 and output enable 733 signals but also the I/O cells PUPD control signals 770 .
[0131] FIG. 6 also shows the output override matrix logic used to select the highest priority override which is enabled for the device pin. Each override defined on a device pin will have an override enable 762 which determines if the override is active or not. If multiple overrides are enabled at the same time for a given device pin precedence is given to the order in which they are specified. A device pin can have the same override type assigned multiple times. There are a number of override types where the actual logic value forced by the override is determined via a signal 763 . Each of these overrides will have an associated override drive signal 763 . The override enable 762 signals and the override drive 763 signals can be driven by complex logical equations which can be placed in the I/O fabric 625 using a custom logic block or else can be driven by logic from inside the core 110 . This means that any logical combination can be used to enable an override.
[0132] The table below describes the effect of the different output override types 724 on the logic values driven on a given device pin.
[0000]
Output Override Type
Effect of Override logic on a device pin
Zero
The device pin is forced to ‘0’ by turning the output signal 732 to ‘0’,
output enable 733 is turned ON and the pull-up and pull-down 770 are
turned OFF.
One
The device pin is forced to ‘1’ by turning the output signal 732 to ‘1’,
output enable 733 is turned ON and the pull-up and pull-down 770 are
turned OFF.
Signal
The device pin is forced to a signal value by assigning the output 732
to a ‘signal’, output enable 733 is turned ON and the pull-up and pull-
down 770 are turned OFF.
Z
This forces the device pin low by turning OFF the output 732, output
enable 733, pull-up and pull-down 770.
PU
This assigns the device pin high by turning the pull-up ON and pull-
down OFF 770, while not affecting the output 732 and output enable
733.
PD
This assigns the device pin low by turning the pull-down ON and pull-
up OFF 770, while not affecting the output 732 and output enable 733.
PUZ
This assigns the device pin high by turning the pull-up ON 770, the
output 732, output enable 733, and pull-down 770 are all OFF.
PDZ
This assigns the device pin low by turning the pull-down ON 770, the
output 732, output enable 733, and pull-up are all OFF 770.
PO
The device pin pull-up and pull-down down 770 are both OFF while
the output 732 and output enable 732 are unaffected.
TestEnableOff
The device pin's test enable signal 820 is driven Low.
OutputEnableOn
The device pin's output enable signal 733 is driven to an OUT_ON
value.
OutputEnable_signal
The device pin's output enable signal 733 is driven to a signal value
763.
PUPDZ_signal
The device pin's PUPD 770 is driven to a signal 763 and the output
enable 733 is driven to OUT_OFF, and the Output 732 is driven LOW
PUPD_signal
The device pin's PUPD 770 is driven to a signal 763. It does not affect
the output 732 or output enable 733.
[0133] When a particular override is enabled for a device pin's output override matrix 724 then the override selection 768 will be ENABLED_ON which ensures that the output signal 764 , output enable 766 and PUPD control 770 will be selected through the cascade of device output path logic shown in FIG. 9 and therefore have priority of control over the output 732 and output enable 733 signals logical values as well as the PUPD control 770 . The PUPD Control signal is a two bit vector that controls the desired pull value on the I/O Cell output.
[0134] The process tool can define an override on chip pin X (which has a bidirectional I/O cell), of type PUZ that is enabled when a hardware port called HIGH_Z on a core interface is active (high). The tool generates the logic such that when a signal called HIGH_Z is active, it will immediately force the output enable inactive and force the PU/PD logic inactive, thereby leaving the output of the buffer high-impedance or as it is known in logical terms—‘Z’. This will remain in this condition until the HIGH_Z goes inactive, independent of the functional or test multiplexing.
[0135] FIG. 8 shows the multiplex selection and control logic 750 and the input override logic 754 which is placed on a core pin's input 752 path. This input path can be the input path for either a functional or test core pin.
[0136] A flexible multiplexing and control structure 750 is generated for the core input path 752 . This multiplexing structure is required because of the need to multiplex N-N device pins because a single core input path 752 can be sourced from multiple device pins 758 multiplexed; likewise a single device pin 758 can be multiplexed onto multiple core input paths. The core input pin can be a functional or a test pin.
[0137] The input multiplex select and control logic 750 has in this embodiment a multiplexer selection signal 714 / 720 per device pin input path 758 which is multiplexed onto this core input path 752 . The actual number of mux selection signals 714 / 720 is dependent on the granularity of the mux selection signal (global, grouped or individual) as described above. In the case where multiple device pin mux selection signals are enabled at the same time then the pin with the lowest mode number takes precedence. If the input core pin 752 is in the same mode on different chip pins 758 and their pin mux selection signals are enabled at the same time then the highest ordered chip pin will take precedence.
[0138] FIG. 8 shows the input override logic 754 used to select the highest priority input override which is enabled for the core input path 752 . Each override defined on a core input path has an override enable 756 which determines if the override is active or not. If multiple overrides are enabled at the same time for a given device pin precedence is given to the order in which they are specified. There are a number of override types where the actual logic value forced by the override is determined via a signal 757 . Each of these overrides has an associated override drive signal 757 . The override enable 756 signals and the override drive 757 signals can be driven by complex logical equations which can be placed in the I/O fabric 625 using a user defined logic block or else can be driven by logic from inside the core.
[0139] The table below describes the effect of the different input override types 754 on the logic values driven on a given device pin.
[0000]
Override Type
Effect of Override logic on a device pin
Zero
The core input path 752 is forced to ‘0’.
One
The core input path 752 is forced to ‘1’.
Signal
The core input path 752 is forced to the value of
the override drive signal 757.
[0140] When a particular override is enabled for a core input path's override matrix 754 then the override selection 759 will be ENABLED_ON which ensures that the override value 760 will be selected through the cascade of core input path logic and therefore have priority of control over the core input 752 .
[0141] A further level of logic is provided in the input multiplexing and control matrix 750 called input protection logic. Because of N-N multiplexing possibilities, it would be possible that for a particular chip pin configuration a specific core input is not used. It is important that if the core input is not used that it is protected from toggling spuriously or given a non-deterministic value as it could cause unknown side effects. The input path needs to be driven by a valid value to avoid undefined logic state when no input multiplex mode is selected 714 / 720 and no input override 754 is enabled. The process tool allows the user to define the protection value of a core input if it has not been selected. Input protection logic can be considered the lowest priority of control or default logic on the input path. It will be the default condition in the input multiplex select and control matrix 750 and therefore does not require a selection signal. The table below describes the effect of the different input protection types on the logic values driven on a given input path 752 .
[0000]
Input Protection Type
Effect of Input Protection
Zero
The core input path 752 is forced to ‘0’ if no other logic type is
selected on the input path.
One
The core input path 752 is forced to ‘1’ if no other logic type is
selected on the input path.
Signal
The core input path 752 is forced to the value of the input
protection drive signal 753 if no other logic type is selected on the
input path.
PinProtect
The core input path 752 will take the value of the device pin input
path 758. This input protection type is only allowed on core input
paths which have a single device pin input path multiplexed.
[0142] Other aspects included in a designed I/O fabric are a) the specific priority of control and b) timing layout of the pin multiplexer and control structures on the output path. The three different types of logic (functional, test, and override) each have different requirements in terms of priority of control and timing layout. Priority of control can be defined as the logic type which will take priority when more than one of the logic types are enabled (active) at a given instance in time. The logic with the highest priority of control will be the logic value driven out on the device pin 732 / 733 or driven in the core input path 752 . Timing layout refers to the number of gates on the logic path and hence the delay that the logic will experience whilst propagating through this part of the integrated circuit.
[0143] Referring to FIG. 9 , the different logic required on both the device pin output path and input paths results is the generation of a cascaded multiplexer arrangement of the output path multiplex select & control matrix 730 , with multiplexers 810 / 812 / 814 / 816 / 818 to achieve the desired control priority and timing priority for the different logic types (functional, test and override). In this diagram the output override box has not been broken out. This arrangement achieves:
maximum control priority for the override signals 766 / 764 , second highest control priority for test signals 716 / 718 , and lowest control priority for the functional signals 710 / 712 . maximum timing priority, having the shortest path, namely the functional output signals, second highest timing priority for the test signals, and lowest timing priority for the override signals.
[0150] The order of priority of control is described based on a default logic ordering (override, test and functional). Where override logic has the highest priority of control and functional logic has the lowest. Likewise, for timing layout in the description of the invention is described in terms of the default timing layout (functional, test and override). In the case of both priority of control and timing layout other realisations of the invention might result in an alternative ordering of the cascaded multiplexer arrangement.
[0151] FIG. 10 shows the I/O control override logic 419 which can be used to control the I/O Cell's control ports 418 . These I/O Cell control ports are used to configure and control the I/O Cell so that it can take account of process, voltage and temperature variations in the operating conditions of the I/O Cell 400 . They can also be used to control specific algorithms such as slew rate, load control, input enable and others. Each control port 418 on the I/O cell instance 400 for a given chip pin 116 can have an I/O control override equation 419 associated with it. I/O control override equations are defined and then associated with I/O cell control ports thus allowing a single definition to be shared across multiple I/O control ports and I/O cell instances. The process tool provides users with the flexibility to choose for the resulting I/O control override logic whether it should be uniquely created for the given I/O cell or shared by a set of I/O cells.
[0152] The I/O control override equations 419 are written in the form of one or more assignment 420 /condition 421 statements which can form complex multiplexing structures, tie off equations or direct connections between the I/O cell control port 418 and the core ports 422 .
[0000] condition?assignment:condition?assignment:assignment
[0153] The equation may be a single assignment statement which therefore allows direct connections and tie-off values to be defined. The condition statements should always evaluate to a Boolean value. An equation language used to define the conditions and assignments is made up of:
Identifiers (port names) Slice ([left: right]) Constants (decimal, binary, octal, hexadecimal numbers) Operators
[0158] A set of rules are enforced to ensure that the identifier will result in the creation of a legal HDL identifier. These identifiers declared in the assignment and condition statements are used to locate ports on the core interface 110 . A slice or portion of the port can be selected using the slice notation [left:right]. The equation language supports different number formats (decimal 1921, binary 0b101, octal 0o36, hexadecimal 0xfA6) in order to declare constants within the assignment and condition statements. The I/O control override equation's language supports a standard set of operators +, −, *, /, **, %, ˜, &, |, ̂, ̂˜, ˜̂, <<, >>, <<<, >>>, !, &&, ∥, ==, !=. Operator precedence can be explicitly defined using brackets.
[0159] The equations can contain substitution sites which are designed to allow flexibility in the port names and constants used by the equations. Through the use of substitution sites a single equation definition can be used across multiple I/O Cell ports where the actual control logic that is generated will be unique to the I/O cell port 418 . On generation 612 the substitution sites are replaced with dynamic information. The table below describes the available set of substitution sites and the dynamic information with which the substitution site can be replaced by:
[0000]
Syntax
Description
${pin}
This substitution site will be replaced by
name of the chip pin 116 associated with
the I/O cell instance 400.
${columnname}
This substitution site will be replaced by
the value in the named column for the current
chip pin 116 which has been captured in I/O
specification 609.
${port}
This substitution site will be replaced by
the name of the I/O Cell port 418 which is
being controlled.
[0160] Through the substitution sites the user has full access to the tool's application programming interface (API). For example, the equation below accesses the last character in a port name (Id2) for a given chip pin (pinY):
${pin}_sel[${port.nodeName.substring(port.nodeName.length( )−1)}]
[0162] When dynamic information is substituted the resulting equation is ‘pinY_sel[2]’. In other realisations other possible substitution sites could be provided such as ${iocell} which might be replaced by the name of the I/O cell 400 used on the chip pin.
[0163] On generation 612 the I/O control override equations 419 are translated into the required RTL representation and the connections to the core interface 422 and the JO cell control interface 418 are created. The user can choose where the logic should be located. By default it is placed in the chip pin's control component. By specifying a location for the equation logic the user can ensure that the same I/O control override logic can be used to control multiple I/O cell ports and thus helps reduce the amount of logic gates required by the I/O fabric.
[0164] Another aspect of the invention is the fragmentation or partitioning of device pin multiplexer and control structures based on power domains which can be used to achieve considerable improvements in energy efficiency. The fact that the logic can be switched off dynamically results in better power efficiency. Unless the logic is fully fragmented it will not be possible to achieve the desired power saving using power design techniques.
[0165] This invention allows pin and input multiplex logic to be fragmented depending on the source domains for each of the possible sources. FIGS. 11 and 12 collectively show how the multiplexer logic can be fragmented by the process tool in order to segment the multiplexer logic into power domains. In FIG. 11 there are six core pin output 710 and output enable 712 signals being multiplexed in a functional output multiplexer 810 and functional output enable multiplexer 812 which belong to two different power domains. The multiplexer logic is constructed as shown in FIG. 11 with no regard to power domain fragmentation. In FIG. 12 the dotted lines represent the original functional output multiplexer 810 and functional output enable multiplexer 812 which have been fragmented across power domain groups. The six core pins being multiplexed belong to two separate power domains. Thus, the output multiplexer 810 is fragmented into two multiplexers 910 , 911 to account for the two power domains at the core level. A final multiplexer 912 belongs to the device pin's power domain and is used to combine the selected output from the two core pin domains. Each multiplexer group 910 / 911 corresponds to an individually switchable domain of the core. This one-to-one mapping allows disabling of the relevant multiplexer circuitry when a core domain is switched off. The device pin domain 912 ensures that a valid value will be driven on the device pin's output path 732 regardless of whether or not all the core pin domains have been switched off or not. The same technique can be applied to the test multiplexer logic 816 / 818 and the override logic 724 .
[0166] In order to achieve this fragmentation of the multiplexer logic each output core pin path 710 / 712 716 / 718 which needs to be test or functionality multiplexed has a power domain associated with it. Core pins with a common power domain are first multiplexed so that all the multiplexer logic for this domain is in a single block.
[0167] This first level of multiplexing is then followed by a second level of multiplexing where this level of multiplexing is in the device pin's power domain. This second level of multiplexing is either the final functional 912 / 913 or the final test multiplexer.
[0168] On a pin-by-pin basis, it is possible to specify three separate power domain properties:
The domain (DL 1 ) for the final functional mux 912 / 913 and I/O cell. The domain (DL 2 ) for the BSRs 225 and I/O cell control logic 419 . The domain (DL 3 ) for the final test mux and override logic.
[0172] The table below shows the domain property which will be assigned to each of the different types of logic which are generated in the I/O fabric.
[0000]
Logic Type
Domain
Comment
Core pins
Core pin's DL
Each core pin on the core will have an associated
710/712/716,/718
domain property
IO Cell 400
Chip pin's DL1
The IO Cell instance will be tagged with the Chip
pin's DL1 property
BSR chain circuitry
Chip pin's DL2
There may be many BSR cells per chip pin placed
225
across the IO Cell's interface 222 (O 412, OE 414, I
416, PUPD 410, Ctrl 418). All these instances are
tagged with the Chip pin's DL2 property.
BSR chain selection muxes 227 are used to select the
path followed through the BSR chain. A chain select
mux 227 will be tagged with the domain of the BSR
cell that is connected to the output of the mux.
Level one functional
Core pin's DL
There will be one multiplexer for each separate core
multiplexing 910/911
pin domain functionally muxed on the chip pin.
Level one test
Core pin's DL
There will be one multiplexer for each separate core
multiplexing
pin domain test muxed on the chip pin.
Second level
Chip pin's DL1
Second level mux of output from all functional core
functional
domain muxes and output from test/override logic
multiplexing 912/913
stages 822/824.
Second level test
Chip pin's DL3
Second level mux of output from all test domain
multiplexing
muxes
Output Override
Chip pin's DL3
Output Override Mux logic
Logic 724
Input Logic 750/754
Core pin's DL
All the input logic is tagged with the associated core
pin's DL property. It is not necessary to fragment the
input logic.
IO Control Overrides
Chip pin's DL2
The IO Control override logic can be placed in the
Logic 419
or User defined
default Chip pin's IO Control block in which case
DL or ‘default’
the Chip pin's DL2 property will be used. If the IO
if undefined
Control logic is shared by multiple chip pin's a user
defined DL will be used.
[0173] The three separate power domain properties on a device pin are used to place different portions its I/O logic into different domains. The values for these three domain properties can be the same.
[0174] The input path's multiplexer select and control logic 750 and the input override logic 754 is placed in the core pin's power domain. As all this logic belongs to the core pin input path's 752 power domain and therefore it is not necessary to fragment the logic.
[0175] The logic fragmentation is designed to make it quite straightforward to create a logic hierarchy based on power domains from the fully fragmented logic. Logic from different device pins which are part of a common power domain can be combined into a logic hierarchy. The process tool allows the desired hierarchy to be generated by allowing logic to be selected depending on its domain or logic type and may be grouped at several different levels to achieve this hierarchy.
[0176] Power optimization can then be applied to the resulting power domain partitioned logic hierarchy. These power optimization techniques, result in the transposing of another layer of logic and control within the I/O fabric 625 , including the insertion of power isolation cells and voltage level shifters on the power domain logic hierarchy boundaries. In order to make it easier to apply these techniques it is necessary in certain cases to create feed-through component instances so that they can be tagged with a domain property to allow the fore-mentioned power optimization techniques to be applied.
[0177] Another aspect of the invention shown in FIG. 13 is the ability to use hand-crafted transistor level logic for timing critical or glitch free paths. RTL to describe the multiplexer logic is automatically generated 612 from the I/O specification 609 . This RTL can then be synthesised into actual transistor level gates. For timing critical or glitch free paths it is possible to choose to utilise transistor level logic which has been hand-crafted to guarantee a particular timing constraint is meet in place of the RTL multiplexer logic automatically generated by the ‘spinner’ tool 601 . This technique can be applied to any part of the multiplexing and I/O cell control circuitry 214 described in previous sections. In the I/O specification 609 users simply need to indicate that hand-crafted logic should be utilised for a given logic type on a given device pin 116 .
[0178] The interface of the hand-crafted transistor level logic, henceforth referred to as a structural multiplexer cell 1001 , shown in FIG. 13 is captured 608 as part of the I/O specification 609 . The I/O specification will contain a library of structural multiplexer cells 1001 whose interface contains a certain number of MuxIn ports 1002 of a particular width; a single MuxOut port 1003 whose width matches the MuxIn ports and a single MuxSelection port 1004 . The ratio of the structural multiplexer cell is defined by the ratio of MuxIn to MuxOut ports. The width of the MuxSelection port is dependent on this ratio. On generation the automatically generated RTL multiplexer logic will be replaced by a structural multiplexer cell from the library which has the required multiplexer ratio and correct MuxIn/MuxOut port width. The MuxIn ports are numerically ordered where the port with the lowest numeric value will have the highest timing priority through the hand-crafted transistor logic. This ensures that the structural multiplexer when connected will maintain the desired timing priority for the different signals being multiplexed.
[0179] The RTL multiplexer logic which is automatically generated by spinner contains both the assignment and condition statements that collectively describe the multiplexer logic. In order to replace it with a structural multiplexer cell the conditional statements must be extracted and used to create a separate RTL multiplexer structure 1005 (condition selection mux) which is used to select the path through the hand-craft transistor logic. Each condition statement is assigned a numeric vector based on its priority in the original RTL multiplexer logic. In the case of the OutputEnable 733 path any polarity issues are automatically handled as part of the original assignment statements of the automatically generated RTL multiplexer logic. Any signals whose polarity is incorrect must be first inverted before entering the structural multiplexer cell.
[0180] The tool allows very flexible device pin multiplexing and control logic to be automatically generated which take into account the unique timing, control priority and power design constraints on the device pins and any core signals which are multiplexed on it.
[0181] Thus far in the description the actual resulting output logic which is created has been described. The algorithms used to create the logic for the I/O fabric are described in representative pseudo-code below. This pseudo-code covers the preferred embodiment described in FIG. 9 for the functional and test output path. The pseudo code does not cover all the corner cases which have been realised in the ‘spinner’ tool 601 , particularly scenarios where logic is omitted (for example, a dedicated core output pin connected directly to an I/O cell output port).
Output Override Logic
[0182] The override logic whose interfaces are described in FIG. 7 is best described using a logic truth table.
[0000]
Output Value
OE Value
Override Selection 768
PUPD Control 770
Override Type
764
766
Out Enable
OE Enable
PUPD Value
PUPD Enable
Zero
0
OUT_ON
ENABLE_ON
ENABLE_ON
PUPD_OFF
ENABLE_ON
One
1
OUT_ON
ENABLE_ON
ENABLE_ON
PUPD_OFF
ENABLE_ON
Signal
SIGNAL
OUT_ON
ENABLE_ON
ENABLE_ON
PUPD_OFF
ENABLE_ON
Z
XX
OUT_OFF
ENABLE_OFF
ENABLE_ON
PUPD_OFF
ENABLE_ON
PU
XX
XX
ENABLE_OFF
ENABLE_OFF
PU_ON
ENABLE_ON
PD
XX
XX
ENABLE_OFF
ENABLE_OFF
PD_ON
ENABLE_ON
PUZ
XX
OUT_OFF
ENABLE_OFF
ENABLE_ON
PU_ON
ENABLE_ON
PDZ
XX
OUT_OFF
ENABLE_OFF
ENABLE_ON
PD_ON
ENABLE_ON
PO
XX
XX
ENABLE_OFF
ENABLE_OFF
PUPD_OFF
ENABLE_ON
TestEnableOff
XX
XX
ENABLE_OFF
ENABLE_OFF
PUPD_OFF
ENABLE_OFF
OutputEnableOn
XX
OUT_ON
ENABLE_OFF
ENABLE_ON
PUPD_OFF
ENABLE_OFF
OutputEnable_signal
XX
SIGNAL
ENABLE_OFF
ENABLE_ON
PUPD_OFF
ENABLE_OFF
PUPDZ_signal
XX
XX
ENABLE_OFF
ENABLE_OFF
SIGNAL
ENABLE_ON
PUPD_signal
XX
XX
ENABLE_OFF
ENABLE_OFF
SIGNAL
ENABLE_ON
[0183] In the case of an override of type TestEnableOff an additional mux in inserted on the test enable path 720 in order to force the disabling of the test logic (enable_off). The values of the constants used in the table above are described here:
[0000]
Constant
Value
OUT_ON
0 (Defaults to output enable negative i.e. OEN
but will match polarity of I/O Cells OE port).
OUT_OFF
1 (Defaults to output enable negative i.e. OEN
but will match polarity of I/O Cells OE port).
ENABLE_ON
1
ENABLE_OFF
0
PUPD_OFF
00
PU_ON
01
PD_ON
11
SIGNAL
The value of the overrides drive signal 763
XX (do not care)
Defaults to 0
LOW
0
HIGH
1
Test Multiplexer Logic
[0184] The pseudo-code below describes how the test output multiplexer logic 816 is created.
[0000]
If a pin has test multiplexing then
Create Test OUT Mux
Default value of mux is LOW
For each pin test-mode sorted in order of priority
If pin test-mode has core pin output (not input only)
add ‘select core pin output when test control equals test
mode’
If has output overrides
add ‘and NOT (override output enable equals
ENABLE_ON)’
End If
End If
Next
If pin has output overrides then
add ‘select override output value when override output enable
equals ENABLE_ON’
End If
Else If pin has output overrides then
connect override output value to functional output multiplexer
End If
[0185] The pseudo-code below describes how the test output enable multiplexer logic 818 is created.
[0000]
If pin's I/O cell has an output enable
If a pin has test multiplexing then
Create Test OE Mux
Default value of OE signal is OUT_OFF
For each test-mode sorted in order of priority
If the test-mode has a core pin muxed
If the core pin has an OE Signal then
If core pin OE polarity not equal to I/O cell's OE port's polarity then
invert core pin OE signal's polarity
End If
add ‘select Core OE signal when test control equals test-mode ’
If has output overrides
add ‘and NOT (override output enable equals ENABLE_ON)’
End If
End If
If the core pin has no OE Signal then
add ‘select OUT_ON for test-mode when test control equals test-mode ’
If has output overrides
add ‘and NOT (override output enable equals ENABLE_ON)’
End If
End If
If the core test pin is an input (no OE Signal) then
add ‘select OUT_OFF when test control equals test-mode’
If has output overrides
add ‘and NOT (override output enable equals ENABLE_ON)’
End If
End If
End If
Next
If pin has output overrides
add ‘select override output enable value when override output enable equals
ENABLE_ON’
End If
Else If pin has output overrides then
connect override output enable value to functional output enable multiplexer
End If
End If
[0186] The ‘test enable value’ forms a portion of test select logic 820 . The test enable is ‘ENABLE_ON’ when ever a test-mode is selected which has a valid output. The test enable logic is best described using the logic truth table below.
[0000]
Test Control 720
Test mode present
Test Enable
0
xx
ENABLE_OFF
Non zero
Has no test output multiplexed
ENABLE_OFF
Non zero
Has test output multiplexed
ENABLE_ON
[0187] The pseudo-code below describes how the test select logic 820 is created.
[0000]
// Test / Override Output Selection logic
If pin has test multiplexing or pin has output overrides then
Create Test/Override OUT Enable mux
Default value is ENABLE_OFF
If pin has test multiplexing
add ‘select ENABLE_ON when test_enable equals
ENABLE_ON’
End if
If pin has output overrides
add ‘select ENABLE_ON when override_out_enable
equals ENABLE_ON’
End If
End If
// Test / Override Output Enable Selection logic
If pin has test multiplexing or pin has output overrides then
Create Test/Override OE Enable mux
Default value is ENABLE_OFF
If pin has test multiplexing
add ‘select ENABLE_ON when test_enable equals
ENABLE_ON’
End if
If pin has output overrides
add ‘select ENABLE_ON when override_OE_enable
equals ENABLE_ON’
End If
End If
Functional Multiplexer Logic
[0188] The pseudo-code below describes how the functional output multiplexer logic 810 is created. It should be clear that the pseudo-code is very similar to that of the test output multiplexer logic 816 described above.
[0000]
If a pin has functional modes then
Create Functional OUT Mux
Default value of mux is LOW
For each pin functional-mode sorted in order of priority
If pin functional-mode has core pin output (not input only)
add ‘select core pin output when pin control equals
functional mode’
If has test/override
add ‘and NOT (test/override output enable equals
ENABLE_ON)’
End If
End If
Next
If pin has test multiplexing or output overrides then
add ‘select test/override output value when test/override output
enable equals ENABLE_ON’
End If
End If
[0189] The algorithm used to create functional output enable multiplexer logic 812 is very similar to that of the test output enable multiplexer logic 818 and therefore no pseudo-code example has been provided.
[0190] The algorithm used to create the functional selection logic 814 is very similar to the test selection logic 820 and therefore no pseudo-code example has been provided.
Input Multiplexer Logic
[0191] The pseudo-code below describes how the input override logic 754 is created.
[0000]
// Input Override value
If a core pin has input overrides then
Create Input Override Mux
Default value is LOW
For each core pin input override in order of priority
If input override type is ONE, add ‘select HIGH when override
enable equals ENABLE_ON’
If input override type is ZERO, add ‘select LOW when override
enable equals ENABLE_ON’
If input override type is Signal, ADD ‘select override drive
signal when override enable equals ENABLE_ON’
Next
End If
// Input Override selection
If a core pin has input overrides then
Create Input Override Enable Mux
Default value is ENABLE_OFF
For each core pin input override in order of priority
add ‘select ENABLE_ON when override enable equals
ENABLE_ON’
Next
End If
[0192] The pseudo-code below describes how a core pin's input multiplexing and protection logic 750 is created.
[0000]
If core pin has input path
If core pin is not dedicated (multiplexed only once) then
Create Core Pin Input Mux
For each functional mode
For each chip pin
If core pin multiplexed in functional mode then
- add ‘select chip pin when chip pin control equals functional mode
For each test-mode
If chip pin has multiplexing in test-modes on current chip pin then
If first then
- add ‘ and NOT (chip pin test control equals test-mode
Else
- add ‘ OR chip pin test control equals test-mode
End If
If last - add’)’
End If
Next
End If
Next
Next
For each test mode
For each chip pin
If core pin multiplexed in test mode then
- add ‘select chip pin when chip pin test control equals test mode’
End If
Next
Next
If core pin input protection is ZERO, add LOW
If core pin input protection is ONE, add HIGH
If core pin protection is Signal, add Protection Signal
// input protection of type pin protection not allowed as core pin is not dedicated
Else if core dedicated but not pin protected
Create Core Pin Input Mux
add ‘select chip pin when chip pin control equals functional mode
For each test-mode
If chip pin has multiplexing in test-modes on current chip pin then
If first then
- add ‘NOT (chip pin test control equals test-mode
Else
- add ‘ OR chip pin test control equals test-mode
End If
If last - add’)’
End If
Next
If core pin input protection is ZERO, add LOW
If core pin input protection is ONE, add HIGH
If core pin protection is Signal, add Protection Signal
End If
End if
[0193] The pseudo-code below describes how the input override logic 754 is combined with the core pin's input multiplexing and protection logic.
[0000]
If a core pin has input overrides then
Create input Ctrl mux
add ‘select input override value when input override selection equals
ENABLE ON
If core pin is dedicated and pin protected then
add input path for chip pin (BSR/IO cell)
Else
add output from Core Pin Input Mux
End If
Connect output of input Ctrl mux to core pin
Else
If core pin is dedicated and pin protected then
connect input path for chip pin (BSR/IO cell) directly to
core pin
Else
connect output from Core Pin Input Mux to core pin
End If
End If
Domain Partitioning
[0194] Domain partitioning is an optional set of algorithms which can be applied to the I/O fabric 625 , the spinner tool 601 supports the generation 612 of logic with or without these techniques being applied.
[0195] The algorithm used to fragment the functional and test output and output enable multiplexer logic 810 , 812 has already been described in FIGS. 11 and 12 .
[0196] A table outlining the domain property which is applied to each logic type in the I/O fabric 625 has already been detailed. When partitioning the I/O fabric it is necessary in certain circumstances to introduce feed-through component instances in order to allow them to be tagged with a domain property. This then allows power isolation and level shifter logic to be easily inserted. A feed-through component is one where the inputs to the component are simply feed-through the component and appear as outputs with no additional logic being inserted. These types of components are normally undesirable as they lead to the creation of unnecessary logic buffers.
[0197] The pseudo-code below describes when a feed-through component should be created on the functional output 710 or output enable 712 paths.
[0000]
If a chip pin has a functional core pin with a unique Domain level for that
chip pin then
If the chip pin path has an Fmux Mux Ctrl defined then
If ChipPin.DL1 is NOT EQUAL to CorePin.DL then
create a domain level feed thru component
End If
Else If chip pin path has No Fmux Mux Ctrl and chip pin has BSR
cell
If ChipPin.DL2 is NOT EQUAL to CorePin.DL then
create a domain level feed thru component
End If
Else If chip pin path has no Fmux Mux Ctrl and No BSR Cell then
If ChipPin.DL1 is NOT EQUAL to CorePin.DL then
create a domain level feed thru component
End If
Else
Don't create Feed thru component
End If
End If
[0198] The pseudo-code below describes when a feed-through component should be created on the test output 716 or output enable 718 paths.
[0000]
If a chip pin has a test core pin with a unique Domain level for that chip
pin then
If CorePin.DL is NOT EQUAL to ChipPin.DL3 then
create a domain level feed thru component
Else
don't create Feed thru component
End If
End If
[0199] The pseudo-code below describes when a feed-through component should be created on a core pin input path 752 .
[0000]
If no input mux component is created for a Core Pin
If the Muxed ChipPin for that CorePin has BSR component then
If CorePin.DL is NOT EQUAL to ChipPin.DL2 then
create a domain level feed thru component
End If
If the Muxed Chip Pin for that Core Pin has NO BSR component then
If CorePin.DL is NOT EQUAL to ChipPin.DL1 (I/O cell
domain)
create a domain level feed thru component
End If
Else (same domain)
Don't create Feed thru mux
End If
End If
Structural Mux Logic
[0200] The pseudo-code below describes how any of the automatically generated multiplexer logic generated by spinner can be replaced by a structural mux cell instantiation.
[0000]
For each mux
If mux marked as needing a structural mux then
Instantiate a structural mux cell matching the required mux ratio
For mux assignment statements in order of priority
If assignment is an equation then
Create equation logic
Connect output of equation logic to MuxIn port of
corresponding priority
Else
Connect assignment signal to MuxIn port of
corresponding priority
End If
Next
Create condition selection mux
For mux condition statements in order of priority
Create numeric value representing priority
Select numeric value when condition
Next
Connect condition selection mux output to structural mux cell's
Selection port
Connect structural mux cell's Output port to output of mux
Remove mux logic
End If
Next
I/O Logic Generation
[0201] Thus far in the description the actual resulting logic which is created has been described as well the individual algorithms used to generate particular portion of the I/O Fabric 625 logic. In order to generate the full logic, the complex dependency graph between the individual algorithms must be described and the actual run order of each of the algorithms defined. The ‘spinner’ tool 601 describes these dependencies using an XML wiring framework and has a wiring engine which uses this XML description too control the order in which individual algorithms are executed. The table below details the main elements of the wiring framework:
[0000]
Term
Description
Wiring Engine
Runtime framework. Manages dependencies between contributors.
Determines based on scope and the set of fulfilled dependencies
whether a contributor should be executed.
Wiring Model
The wiring forms the skeleton or structure of the synthesis process
which will be run but does not define the logic which will be
generated. It essentially defines the dependency hierarchy of the
contributors. It is described using an XML syntax.
Wiring Context
The wiring context contains the run time information passed to the
contributors.
Source Model
The input model/design data. In the case of spinner this is the I/O
specification 609.
Target Model
The output model/design data, where the results of the synthesis
will be stored. In the case of spinner this is the I/O Fabric 625 logic
represented as software objects.
Slot/mailbox
A slot is a message box which can hold an object of data. It is used
by the wiring framework to pass information between contributors
using the requires/provides wiring model declarations.
Contributor
Implementation of a transformation (algorithm) which needs to be
performed during the synthesis.
Contribution/
A contribution is used to bind a Contributor to some of the wiring
Contribution
model structural (block, hook) elements. The set of contributions
Declaration
within the wiring model defines the dependency between
contributors and thus their synthesis run order. A contribution
declaration can contain zero or more required bindings and zero or
more provided bindings.
Block
A block is a named container (wiring structural) element, which can
contain other types of elements. It can be bound too contribution
declarations via its name.
Hook
A hook is a named leaf (wiring structural) element whose sole
purpose is to be bound to contributions via slots.
Bind/Binding
A bind is owned by a contribution and defines a mapping between a
named slot (used by the contributor at runtime to access data) and a
wiring model structural element (block, hook) used to link
contributions into a dependency hierarchy.
Connection
A short-hand notation to define a contribution declaration for the
‘ConnectionInstanceContributor’ contributor.
Scope
The scope is used to define the dimensions of the wiring model. A
scope attaches a scope handler implementation to the wiring model.
ScopeHandler
Implementation which at wiring runtime is used to determine how
often the contributors which fall within this scope will be run via
the wiring context.
[0202] The wiring framework is a generic technology which can be used to generate any type of hardware logic which can be described via a set of interdependent algorithms. The wiring model XML is human readable and therefore can be modified to insert new contribution steps (algorithms) or change the generated logic (E.g. the cascaded order of the multiplexer logic thus achieving an alternative priority of control and timing layout for the pin multiplexer and control structures 730 on the output path).
[0203] The wiring model consists broadly of two types of elements; structural elements and contribution specification elements.
[0000]
Structural Elements
Contribution Specifications
Block
Contribution
Hook
Bind
Connection
[0204] The structural portion of the wiring defines a set of elements which can be bound to contributor slots and therefore forms a structural fabric which is used to communicate information (messages) between the various contributors during the synthesis. They are basically a tree of named elements. Block and hook wiring model elements can be bound too by a contribution declaration using a bind. Where two contributions bind to the same structural element (Block or Hook) then these contributors can pass information to each other. Therefore as stated above they form a structural fabric to allow contributors to pass information via slots (mailboxes) to each other.
[0205] The contribution specification portion of the wiring model essentially defines the set of contributors which will be involved in the generation of the logic and allows the dependencies between the different contributors to be defined so that their run order can be determined. A contribution declaration can contain zero or more required binds and zero or more provided binds. A bind creates a two way binding:
Slot binding—used at synthesis runtime to allow the contributors to retrieve data from required binds and post data to provided binds via named slots. Element binding—Specifies the dependency between contributions. One contribution provides while zero or more contributions can require the binding. When binds refer to the same structural element then they are linked thus creating the dependency hierarchy.
[0208] The required binds define which slots (message boxes) must be filled before the contributor associated with the contribution declaration can be run. The provided binds effectively specifies a contract that the contributor aims to fulfil by putting data into these slots when it is run.
[0209] The scope element is used to define the dimensions of the wiring model. The scope declaration should be considered a marker which associates a scope/dimension to the elements that it (the scope declaration) contains. A scope declaration references a scope handler. The scope handler is an implementation which determines how often the contributors will be run via the wiring context. In the spinner wiring model some sample scopes include:
Set of Chip Pins; Set of BSR Chains; Set of Core pins.
[0213] The table below shows a small portion of the wiring framework used by the ‘spinner’ tool 601 which is used to create the input override 754 and input multiplexing and control matrix 750 logic.
[0000]
<block name=′input-muxing′>
<hook name=′pin_conf_mode′/>
< hook name=′input-overrides′/>
< hook name=′core-pin′/>
< hook name=′protection′/>
< hook name=′core-pin-pads′/>
< hook name=′input-struct-mux′/>
</block>
<scope name=′core-pin-scope′>
<contribution name=′input-mux-comp-contrib′ contributor=′ComponentContributor′>
<bind slot=′CONTAINER′ required=′true′ element=′top′/>
<bind slot=′INSTANCE′ provided=′true′ element=′input-muxing′/>
</contribution>
<contribution name=′input-mux-contrib′ contributor=′InputMuxContributor′>
<bind slot=′CONTAINER′ required=′true′ element=′input-muxing′/>
<bind slot=′CORE_PIN′ required=′true′ element=′input-muxing/core-pin′/>
<bind slot=′CHIP_PINS′ required=′true′ element=′input-muxing/core-pin-pads′/>
<bind slot=′CONF_MODES′ opt_required=′true′ element=′input-muxing/pin_conf_mode′/>
<bind slot=′INPUT_OVERRIDE′ opt_required=′true′ element=′input-muxing/input-
overrides′/>
<bind slot=′PROTECTION_CP′ provided=′true′ element=′input-muxing/protection′/>
<bind slot=′STRUCT_MUX′ provided=′true′ element=′input-muxing/input-struct-mux′/>
</contribution>
<contribution name=′struct-mux-contrib′ contributor=′StructuralMuxContributor′>
<bind slot=′CONTAINER′ required=′true′ element=′input-muxing′/>
<bind slot=′STRUCT_MUX′ required=′true′ element=’input-muxing/input-struct-mux′/>
</contribution>
<contribution name=′input-mux-conf-mode-locator′ contributor=′CorePinConfModeLocator′>
<bind slot=′CONTAINER′ required=′true′ element=′core′/>
<bind slot=′CONF_MODES′ provided=′true′ element=′input-muxing/pin_conf_mode′/>
</contribution>
<contribution name=′input-mux-core-pin-port-locator′ contributor=′InputCorePortLocator′>
<bind slot=′CONTAINER′ required=′true′ element=′core′/>
<bind slot=′PORT′ provided=′true′ element=′input-muxing/core-pin′/>
</contribution>
<contribution name=′input-override-locator′ contributor=′OverrideLocatorContributor′ >
<bind slot=′CONTAINER′ required=′true′ element=′top′/>
<bind slot=′CORE′ required=′true′ element=′core′/>
<bind slot=′unused-slot-but-needed-no-ensure-custom-dependency′ opt_required=′true′
element=′custom-instances′/>
<bind slot=′PIN_OVERRIDES′ provided=′true′ element=′input-muxing/input-overrides′/>
</contribution>
<contribution name=′protection-locator′ contributor=′input.ProtectionLocatorContributor′>
<bind slot=′CONTAINER′ required=′true′ element=′top′/>
<bind slot=′CORE′ required=′true′ element=′core′/>
<bind slot=′unused-slot-but-needed-no-ensure-custom-dependency′ opt_required=′true′
element=′custom-instances′/>
<bind slot=′PROTECTION_CP′ required=′true′ element= ′input-muxing/protection′/>
</contribution>
<contribution name=′chip-pin-locator′ contributor=′IoCellInputsLocator′>
<bind slot=′CONTAINER′ required=‘‘′true′ element=′top′/>
<bind slot=′PIN_INPUTS′ provided=′true′ element=′input-muxing/core-pin-pads′/>
</contribution>
</ScopeRef>
[0214] FIG. 15 should be read in conjunction with the previous portion of the overall spinner wiring xml, which explains how the dependencies between the contributors which create the input override 754 and input multiplexing and control 750 logic are resolved. It shows how the wiring engine will resolve the dependencies between the different contributors which need to be executed in order to construct the input override 754 and input multiplexing and control 750 logic. FIG. 15 shows that for each core pin in the ‘core-pin-scope’ there will be a maximum of three synthesis passes. The core and the chip top components must already be available in the wiring context before the ‘core-pin-scope’ will be executed. On the first pass for a given core pin the wiring engine will determine that the contributors below have their required dependencies (required slots) fulfilled and therefore will execute them in the order they appear in the wiring XML:
[0000]
Contribution name
Description
input-mux-comp-contrib
Determines if the core-pin requires a input multiplexing component.
A component is not required if the core-pin is dedicated, is pin
protected and does not have any input overrides instead a direct
connection will be created.
input-mux-conf-mode-
Locates each of the pin control 714 and test pin control 720 ports on
locator
the core interface that control the functional and test modes that this
core pin is multiplexed in.
input-mux-core-pin-port-
Locates the port on the core interface which corresponds to this core
locator
pin's input path 752.
input-override-locator
Locates the override enable 756 and override drive 757 ports which
are used by the input overrides defined on the core pin.
chip-pin-locator
Locates either the input port 416 on the I/O Cell or else that BSR
cell's data out port 512 for each of the chip pins that this core pin is
multiplexed on.
[0215] On the second pass the wiring engine will see if any further contributors have had their dependencies fulfilled. The only potential candidate is the ‘input-mux-contrib’. This is the contributor which implements the algorithm previously described to create input multiplexer 750 and override 754 logic. The ‘input-mux-contrib’ contributor will potentially provide two slots PROTECTION_CP and STRUCT_MUX. Depending on whether the slots have been provided the wiring engine will determine if the following two contributors should be executed in the third pass.
[0000]
Contribution name
Description
struct-mux-contrib
If the STRUCT_MUX slot was provided in the
previous pass then the structural mux logic
algorithm described earlier will be executed.
protection-locator
If the core pin is protected to a signal then
this contributor will locate this signal 753
and connect it to the input port on the input
mux component.
[0216] The wiring engine moves onto the next core pin in the scope when a pass occurs where no new contributors have had their dependencies fulfilled. The same steps will be repeated for each core pin in the scope.
Description of Alternative Realisation
[0217] The invention is not limited to the embodiments described but may be varied in construction and detail.
[0218] FIG. 14 shows an alternative embodiment of how the output and output enable logic can be generated. Comparing it against FIG. 9 the main difference is that the multiplexers 810 , 812 , 816 , 818 shown as have been implemented in two stages. The multiplexers 810 , 812 , 816 , 818 are shown as dotted lines on FIG. 14 . In the first stage on FIG. 14 the functional output 1110 , functional output enable 1111 , test output 1112 and test output enable 1113 signals are multiplexer without regard to any other logic in the overall cascade of logic. This simplifies these multiplexer because they can be written as ‘select core pin output when pin control equals functional mode’ without the need to add the additional checks to ensure that test or override logic is not enabled ‘and NOT (test/override output enable equals ENABLE_ON)’. The output for these first stage multiplexers is then feed into a Mux Control stage 1120 , 1121 , 1122 , 1123 where selection over which particular logic type has priority of control is decided. The second difference between the logic arrangements in FIG. 9 and FIG. 14 is that in the case of FIG. 15 the test and override logic have essentially identical timing priority. Functional logic has the fastest timing priority in both embodiments. Domain fragmentation can be applied to the multiplexer logic 1110 , 1111 , 1112 , 1113 shown in FIG. 14 using the same technique described in FIGS. 11 and 12 .
|
This invention concerns an automated method of generating a design for an I/O fabric of a target integrated circuit having a core and pins. A process tool executes algorithms to generate a synthesizable representation of the I/O fabric ring in hardware description language. It imports integrated circuit design data, and from it captures I/O specification data for a circuit core, library of cells, pin, I/O control, BSR and I/O cell chaining, and die. The tool validates the specification data, and generates the I/O fabric design by configuring and inter-connecting a pin multiplexing and control matrix structures according to constraints for signal control, and timing. The structures includes on both the input and output paths of each pin a functional multiplexer matrix structure, a test multiplexer matrix structure, an override matrix structure, a multiplex select and control matrix structure, and an I/O Cell control logic. A required pin output circuit is configurable by modification of the I/O specification data, and/or, modification of a manner of wiring the algorithms, and/or by modification of the algorithms. The tool wires algorithms according to a wiring framework, and said wiring framework is modifiable.
| 6
|
BACKGROUND OF THE INVENTION
This invention relates to pop-up sprinklers and in particular to a housing for protection against intrusion of sand, dirt and debris into pipe threading, into underground pipes to which they connect and onto related sprinkler components when the sprinklers are repaired, replaced, removed for cold-weather-freeze protection or otherwise displaced.
Currently, pop-up sprinklers about 6-to-10 inches long and 11/2-to-21/2 inches in diameter are inserted into holes in ground to where they are pipe-threaded vertically onto underground pipe threads. When the sprinklers are removed for adjustment, repair, replacement or for cold-weather-freeze protection, sand, dirt and debris from sides of the holes and from around the holes falls in onto pipe threading, enters the pipe and often caves into the holes. In addition, some types of soil sticks to the sprinklers and makes their replacement in the holes difficult. Cleaning the holes out and cleaning the sprinklers off to put them back into the holes requires considerable time, effort, frustration and cost. There are no known means for solving this problem with the convenience, efficiency and effectiveness of this invention.
Examples of different but related means are described in the following patent documents. Japanese Patent Publication Number 06277566 A, filed by Chiaki, et al., described a cylindrical housing above the ground to fit over a rotating sprinkler that projected above ground surface. U.S. Pat. No. 5,213,262, issued to Violette, described a sprinkler-head guard with an annulus for containing ballast material around a sprinkler cylinder. U.S. Pat. No. 5,137,307, issued to Kinsey, described a single sleeve housing without length adjustment for covering a pop-up sprinkler head. U.S. Pat. No. 4,763,837, issued to Livneh, taught a water-release valve on a sprinkler head for preventing cold-weather freezing. U.S. Pat. No. 4,781,327, issued to Lawson, et al., taught a protective sleeve that was raised and lowered protectively by raising and lowering of a pop-up sprinkler head. U.S. Pat. No. 4,010,901, issued to Sheets, taught a pop-up sprinkler in a protective housing. U.S. Pat. No. 3,265,310, issued to Cohen, taught a protective cylinder positioned in ground around a sprinkler and having a removable lid.
SUMMARY OF THE INVENTION
In light of continuing need for improvement of sprinkler protection, objects of this invention are to provide a pop-up-sprinkler housing which:
Prevents sand, dirt and debris from caving into sprinkler holes and entering underground plumbing when pop-up sprinklers are removed for service, replacement or winter storage in freeze zones; and
Prevents contact of outside surfaces of pop-up sprinklers with sticky soil and other material that cause deterioration and obstruct movement of a pop-up-sprinkler shaft in and out of a hole in the ground for pop-up action and for servicing.
This invention accomplishes these and other objectives with a pop-up-sprinkler housing having a cap sleeve that slides adjustably into a base sleeve having a base plate with a fluid conveyance that screws onto underground sprinkler plumbing and into a sprinkler shaft. A housing cap on top of the cap sleeve has a sprinkler-shaft aperture that is sized and shaped to allow ingress and egress of pop-up portions of select sprinkler shafts and has cap-sleeve shoulders that extend over the base sleeve and a support surface. Thread fastener means are provided for attaching the fluid conveyance to the sprinkler shafts and to the underground sprinkler plumbing.
The above and other objects, features and advantages of the present invention should become even more readily apparent to those skilled in the art upon a reading of the following detailed description in conjunction with the drawings wherein there is shown and described illustrative embodiments of the invention.
BRIEF DESCRIPTION OF DRAWINGS
This invention is described by appended claims in relation to description of a preferred embodiment with reference to the following drawings which are described briefly as follows:
FIG. 1 is a partially cutaway elevation view;
FIG. 2 is a partially cutaway fragmentary top section with a sprinkler shaft removed for servicing or for winter storage and having a protective cap;
FIG. 3 is a partially cutaway fragmentary pipe-attachment section with an affixed pipe nipple for attachment to underground sprinkler plumbing and to a pop-up-sprinkler shaft;
FIG. 4 is a partially cutaway fragmentary pipe-attachment section showing a pipe nipple affixed with straight-thread fastener nuts on straight threads inwardly from pipe threads for attachment to underground sprinkler plumbing;
FIG. 5 is a partially cutaway fragmentary pipe-attachment section showing a pipe nipple affixed with set-screw sleeves inwardly from pipe threads for attachment to underground sprinkler plumbing;
FIG. 6 is a partially cutaway fragmentary pipe-attachment section showing a combination pipe nipple for attachment to underground sprinkler plumbing;
FIG. 7 is a partially cutaway fragmentary portion of a top portion of a sprinkler shaft being retained by a third of a plurality of sprinkler adapters that are attachable with a snap type of quick disconnect;
FIG. 8 is an exploded fragmentary portion of the FIG. 7 snap type of quick disconnect in assembly succession;
FIG. 9 is a top view of one of a plurality of sprinkler adapters having a leaf-thread type of quick disconnect;
FIG. 10 is a partially cutaway side view of the FIG. 9 illustration;
FIG. 11 is a partially cutaway side view of a cap-sleeve shoulder having a leaf-thread type of quick disconnect; and
FIG. 12 is a partially cutaway fragmentary portion of a top portion of a sprinkler shaft being retained by a third of a plurality of sprinkler adapters that are attachable with a leaf-thread type of quick disconnect.
DESCRIPTION OF PREFERRED EMBODIMENT
For purposes of describing the preferred embodiment, the terminology used in reference to the numbered components in the drawings is as follows:
______________________________________1. Cap sleeve2. Base sleeve3. Base plate4. Fluid conveyance5. Pipe-attachment portion6. Sprinkler-attachment portion7. Top machine threads8. Sprinkler shaft9. Bottom machine threads10. Underground sprinkler plumbing11. Housing cap12. Sprinkler aperture13. Pop-up portions14. Cap-sleeve shoulder15. Top surface16. Sprinkler-irrigation surface17. Drain orifice18. Attachment sleeve19. Circumferential step20. Step cap21. Straight-thread nuts22. Straight threads23. Set-screw sleeves24. Set screws25. Pipe nipple26. First reducer pipe nipple27. First connector sleeve28. Second connector sleeve29. Second reducer pipe nipple30. Pipe sleeve nuts31. Sprinkler adapters32. Snap bosses33. First walls34. Snap receptacles35. Second walls36. Leaf threads37. Circumferential-channel threads38. Thread-entry bays39. Top channel walls40. Pop-up-housing portion______________________________________
Reference is made first to FIG. 1. A cap sleeve 1 has an outside periphery in sliding contact with an inside periphery of a base sleeve 2 with an open top end through which the cap sleeve 1 is inserted selectively into the base sleeve 2. A bottom end of the base sleeve 2 has a base plate 3. A fluid conveyance 4 attached centrally to the base plate 3 has a pipe-attachment portion 5 extended linearly downward from a bottom surface of the base plate 3 and a sprinkler-attachment portion 6 extended linearly upward from a top surface of the base plate 3.
The sprinkler-attachment portion 6 of the fluid conveyance 4 has top machine threads 7 onto which select types and sizes of sprinkler shafts 8 can be screwed. The pipe-attachment portion 5 of the fluid conveyance 4 has bottom machine threads 9 that can be screwed into underground sprinkler plumbing 10.
A top end of the cap sleeve 1 has a housing cap 11 with a sprinkler aperture 12 that is sized and positioned centrally in the housing cap 11 to allow ingress and egress of pop-up portions 13 of the sprinkler shafts 8. A cap-sleeve shoulder 14 is extended outward radially from the cap sleeve 1 for arresting excessive entry of the cap sleeve 1 into the base sleeve 2 by positioning the cap-sleeve shoulder 14 on a select top surface 15 of an area at a desired height in relationship to a targeted sprinkler-irrigation surface 16 that is represented by vertical lines to indicate lawn and other irrigable vegetation.
The base plate 3 can have at least one drain orifice 17 to allow underground escape of residual water.
The housing cap 11 can be attached detachably to the cap sleeve 1 with attachment sleeves 18 or other means. This allows use of housing caps 11 having different sizes and shapes of sprinkler apertures 12 for different sizes and types of pop-up sprinklers having different sizes and types of sprinkler shafts 8 or substitutional equivalents thereof. Sizes and shapes of the cap sleeve 1 and the base sleeve 2 also can be adjusted to different types, sizes and shapes of pop-up sprinklers. With a wide selection of sizes of sprinkler apertures 12 for a selection of sizes of cap sleeves 1 and base sleeves 2, this pop-up-sprinkler housing is highly adaptable to different types and sizes of pop-up sprinklers.
The underground sprinkler plumbing 10 generally is made of PVC but can be metallic. Although PVC is a preferred material for construction of this invention and for underground sprinkler plumbing 10, other types of materials are foreseeable and intended within the scope of this invention.
Referring to FIG. 2, the housing cap 11 can have a circumferential step 19 positioned circumferentially external to the sprinkler aperture 12. The circumferential step 19 has multiple uses. It allows convenient construction for different sizes of sprinkler apertures 12 with an otherwise single size range of housing caps 11. It also provides a base with a housing for receiving and supporting a step cap 20 to close the sprinkler aperture 12 when a pop-up sprinkler or portions of it may be removed for servicing or winter storage in freeze zones.
Referring to FIGS. 3-6, the fluid conveyance 4 can be attached to the base plate 3 with various means. All provide a sprinkler-attachment portion 6 projected upwardly and a pipe-attachment portion 5 extended downwardly.
FIG. 3 depicts a pipe-attachment portion 5 and a sprinkler-attachment portion 6 constructed integrally with the base plate 3.
FIG. 4 depicts a pipe-attachment portion 5 and a sprinkler-attachment portion 6 fastened to the base plate 3 with straight-thread nuts 21 on straight threads 22 inward linearly from pipe-nipple threads. The fluid conveyance 4 for this embodiment is a pipe nipple having pipe threads on opposite ends and straight threads 22 on a center portion with a slightly larger diameter for the straight-thread nuts 21.
FIG. 5 depicts a pipe-attachment portion 5 and a sprinkler-attachment portion 6 fastened to the base plate 3 with set-screw sleeves 23 having set screws 24 engaging a pipe nipple 25 internally from pipe-nipple threads. The fluid conveyance 4 for this embodiment is a pipe nipple 25 having pipe threads on opposite ends and preferably no threads in a center portion.
FIG. 6 depicts a built-up combination of conventional pipe connectors for construction of the fluid conveyance 4. It has a pipe-attachment portion 5 and a sprinkler-attachment portion 6 fastened to the base plate 3 with a built-up combination of conventional pipe connectors or fittings available in consumer markets. A first reducer pipe nipple 26 has a minor diameter with pipe threads that screw into the underground sprinkler plumbing 10 and a major diameter with threads that screw into internal threads on a first connector sleeve 27. Screwed into internal threads of an opposite end of the first connector sleeve 27 is a second connector sleeve 28 that has internal threads into which threads on a minor diameter of a second reducer pipe nipple 29 are screwed. A major diameter of the second reducer pipe nipple 29 is screwed into internal threads of the sprinkler shaft 8.
Referring further to FIGS. 1 and 5, another built-up combination using conventional components to construct a fluid conveyance 4 is a pipe nipple 25 shown in FIG. 1 having slightly enlarged pipe-sleeve nuts 30 engaging opposite surfaces of the base plate 3.
Other built-up combinations of conventional pipe connectors are foreseeable for constructing the fluid conveyance 4 on opposite sides of the base plate 3 for fluid communication intermediate the underground sprinkler plumbing 10 and the sprinkler shaft 8.
Referring to FIGS. 7-8, a plurality of sprinkler adapters 31 can be attached telescopically to the cap-sleeve shoulder 14 directly as depicted or indirectly through the housing cap 11 described in relation to FIG. 1. The sprinkler adapters 31 can be joined together and joined to the cap-sleeve shoulder 14 with a selection of fastener or joining means. Preferably, the joining means is a form of quick-disconnect. The quick-disconnect can be a snap type having snap bosses 32 in first walls 33 and snap receptacles 34 in second walls 35 of telescopic sections of the sprinkler adapters 31. First walls 33 can be adapter sleeves of the sprinkler adapters 31 and second walls 35 can be adapter bases as depicted or vice versa. The snap receptacles 34 are preferably quarter-circle channels positioned as shown and extended full-circle circumferentially to avoid need for lining up snap bosses 32 with snap receptacles 34. The snap bosses 32, however, are preferably quarter-spherical protrusions in order to impart inwardly bending pressure on only a relatively small portion of first walls 33. Different proportions also can be employed.
Referring to FIGS. 9-12, the quick-disconnect can be a leaf-thread type having leaf threads 36 extended outward radially from outside peripheries of first walls 33 of the sprinkler adapters 31, circumferential-channel threads 37 extended outward radially from inside peripheries of second walls 35 of the sprinkler adapters 31 and thread-entry bays 38 in top channel walls 39 of the circumferential-channel threads 37. The circumferential-channel threads 37 can be but need not be inclined or helical for a portion of a circular or arcuate extension in inside peripheries of the second walls 35 of the sprinkler adapters 31.
Inside peripheries of the sprinkler adapters 31 are sized, shaped and positioned to engage outside peripheries of pop-up-housing portions 40 of sprinkler shafts 8 described in relation to FIG. 1 as shown.
To use the snap type of quick-disconnect, sprinkler adapters 31 are merely positioned in telescopic relationship and pushed together linearly for attachment or pulled apart linearly for detachment. To use the leaf-thread type of quick-disconnect, sprinkler adapters 31 are positioned in telescopic relationship with leaf threads 36 in line circumferentially with thread-entry bays 38, pushed together linearly and then turned a portion of a revolution. To detach the leaf-thread type of quick-disconnect, the sprinkler adapters 31 are turned back the same portion of a revolution and pulled apart linearly.
A new and useful pop-up-sprinkler housing having been described, all such foreseeable modifications, adaptations, substitutions of equivalents, mathematical possibilities of combinations of parts, pluralities of parts, applications and forms thereof as described by the following claims and not precluded by prior art are included in this invention.
|
A pop-up-sprinkler housing has a cap sleeve (1) that slides adjustably into a base sleeve (2) having a base plate (3) with a fluid conveyance (4) that screws onto underground sprinkler plumbing (10) and into sprinkler shafts (8). A housing cap (11) on top of the cap sleeve has a sprinkler-shaft aperture (12) that is sized and shaped to allow ingress and egress of pop-up portions (13) of select sprinkler shafts and has cap-sleeve shoulders (14) that extend over the base sleeve and a support surface (15). Threaded fasteners are provided for attaching the fluid conveyance to the sprinkler shafts and to the underground sprinkler plumbing. A plurality of sprinkler adapters 31 are provided for adaptation to different sizes and types of pop-up sprinklers.
| 1
|
CROSS REFERENCE TO PROVISIONAL APPLICATION
This application claims the benefit of U.S. Provisional application Ser. No. 60/104,801 filed Oct. 19, 1998.
FIELD OF THE INVENTION
The present disclosure concerns the field of gene therapy applied to vascular smooth muscle cells (VSMC) for the purpose of preventing formation of atherosclerotic lesions, and for treating atherosclerotic plaque and sites of vascular injury.
BACKGROUND OF THE DISCLOSURE
Vascular smooth muscle cell proliferation in response to injury is an important etiologic factor in vascular proliferative disorders such as atherosclerosis and restenosis after vascular injury caused by invasive medical techniques. Vascular injury caused by the percutaneous revascularization and other interventions stimulates the proliferation and migration of VSMC (Clowes et al., 1983, Schwartz et al., 1993, and Gordon et al., 1990). Migration of VSMC to the lumen of the injured site has been shown to be more critical to the pathogenesis of restenosis in some animal models than proliferation of VSMC per se (Schwartz et al., 1995, Schwartz et al., 1996).
This intimal accumulation of VSMC, through proliferation and migration from the media of the vessel, significantly contributes to restenosis after percutaneous revascularization interventions (Clowes et al., 1983, Schwartz et al., 1993, and Schwartz et al., 1995). The accumulation of intimal smooth muscle cell is also prominent after carotid balloon injury in rats (Clowes et al., 1983), after coronary balloon angioplasty in pigs (Schwartz et al., 1993) and in instances of restenosis after arterial dilatation in humans (Gordon et al., 1990, O'Brien et al., 1993). VSMC also contribute to the production of extracellular matrix, which increases the bulk of the neointimal mass obstructing the vessel lumen after balloon angioplasty, stenting, or other interventions that have transiently restored blood flow (Clowes et al., 1983, Schwartz et al., 1993, Schwartz et al., 1995, and Schwartz 1996).
One strategy employed for maintaining vascular patentcy after vascular injury is to induce apoptosis (cell death) of VSMC as a result of gene transfer. For example, the transfer of a replication-defective adenovirus encoding a non-phosphorylatable, constitutively active form of the retinoblastoma gene product (pRb) into VSMC inhibits the cells entry into S-phase after endovascular balloon angioplasty in rat carotid and porcine femoral artery models of restenosis (Chang et al., 1995). Adenoviral vectors encoding the herpes virus thymidine kinase (tk) gene have been introduced into porcine arteries injured with a balloon catheter (Ohno et al., 1995). When the tk gene was activated by ganciclovir treatment, intimal hyperplasia decreased.
Walsh et al. reported the prevention of restenosis with the transfer of the Fas-ligand (FasL) gene into balloon catheter injured rat carotid arteries (Sata et al., 1998). When the FasL binds to Fas (CD95) a transduction of a cytolytic signal occurs in the cell, which leads to apoptosis (Griffith, T. S. et al., 1995). Another report by Pollman and associates describes regression of vascular lesions by induction of cell death through inhibition of the death repressor gene, bc1-2 (Pollman et al., 1998). Yonemitsu et al., have described the gene transfer of p53, which was reported to prevent restenosis in balloon catheter injured rat carotid arteries (Yonemitsu et al., 1998). However, p53 induced growth arrest also occurs via the induction of p21 and, thus the p53, is not a pure “killer” gene.
The E2F-1 family of transcription factors appears to play a critical role in the transcription of certain genes required for cell cycle progression from G 1 to S phase. E2F-1, the first cloned member of this family, is regulated during the cell cycle at the mRNA level by changes in transcription of the E2F-1 gene and at the protein level by complex formation with proteins such as the retinoblastoma gene product (pRb), cyclin A, and DP1. The E2F-1 gene encodes a nuclear protein, retinoblastoma-associated protein 1 (“E2F-1” or “RBAP-1”), that binds to the underphosphorylated form of human retinoblastoma (pRB), a protein that is known to repress the progression of cells towards S phase.
pRb has two known major functions. One of its functions is to sequester or inactivate the transcription factor E2F-1 which is required for activation of S phase genes. The second major function is to regulate the activity of polymerase I and III (pol I and pol III). The pRB appears to be the major player in a regulatory circuit in the late G 1 phase, the so called restriction point. Moreover, pRb is involved in regulating an elusive switch point between cell cycle, differentiation and apoptosis.
A prerequisite for the growth-suppressing function of pRB is binding to the E2F-1 transcription factor, thus inhibiting transcriptional activation of genes by the E2F-1 protein which are required for DNA synthesis (Helin et al., 1992 and Nevins 1992) and cell cycle progression from G1 to S phase. Inactivation of pRb by either phosphorylation, mutation or oncoprotein binding disrupts the Rb/E2F complex and results in E2F-1 activation. Analogous, overexpression of E2F-1 can override the pRb-mediated Glarrest (Zhu et al., 1993, Qin et al., 1995, Neuman et al., 1996) and lead to either cellular transformation (Singh et al., 1994, Xu et al., 1995, Johnson et al., 1994b) or promote premature S phase entry (Qin et al., 1994 Shan and Lee 1994, Shan et al., 1996, Kowalik et al., 1995).
Several laboratories have shown a direct relationship in the transfer of the E2F-1 gene into cancer and immortalized cells and the subsequent apoptotic death of those cells. An adenovirus carrying E2F-1 (Ad.E2F-1) has been described by DeGregori et al., who observed a promotion of quiescent transformed immortalized rat fibroblast cell line, REF52, into S-phase and apoptosis (cell death), after E2F-1 gene transfer (DeGregori et al., 1997). Hunt et al., have shown that Ad.E2F-1 can kill in vitro human breast and ovarian carcinoma cell lines (Hunt et al., 1997). The E2F-1 gene, transferred by Ad.E2F-1, induces apoptosis in tumors (gliomas) in vivo, resulting in the regression of tumors, thus showing the potential therapeutic promise of E2F-1 gene transfer in cancer (Fueyo et al., 1998). Agah and associates transferred the E2F-1 gene into adult rat ventricular myocytes both in vivo and in vitro in an effort to induce myocyte proliferation after infarction (Agah et al., 1997). Instead they found that E2F-1 gene transfer led to apoptosis of the myocytes independent of the tumor suppressor protein p53.
Other reports suggested that overexpression of E2F-1 was associated with accelerated proliferation of cultured fibroblasts (Johnson et al., 1994). E2F-1 appears to have divergent growth regulatory functions, dependent on tissue type, developmental stage, and the coexistence of other genes. Prior to the present invention, no previous investigation of E2F-1 gene transfer to non-tumoral or non-immortal cell lines or tissue had been performed.
Prior to the invention herein, it was not known whether the migration and proliferation of normal vascular smooth muscle cells could be effectively reduced at the site of vascular injury by the local in vivo transformation of VSMC following injury. Moreover, it was not known whether gene therapy of VSMC could reduce atheroma formation in atherosclerotic disease states.
SUMMARY OF THE INVENTION
The present disclosure provides that vascular smooth muscle cells (VSMC) are driven into S-phase and thereby to their subsequent death because of E2F-1 transfer. E2F-1 transformed VSMC suppress VSMC growth, restenosis, and promotes the regression of atherosclerotic plaques. E2F-1 gene transfer to arteries and vein grafts, in accordance with methods of the disclosure, is useful to prevent atherogenesis and fibroproliferative disorders in arteries, vein grafts, arteriovenous fistulas and stent grafts.
The disclosure teaches a method of using vascular E2F-1 gene transfer to prevent vascular smooth muscle cell (VSMC) accumulation contributing to arterial restenosis after percutaneous revascularization interventions is provided. Examples of such interventions are balloon angioplasty and vascular stenting.
The present disclosure also provides a method of employing gene transfer of E2F-1 to prevent VSMC accumulation and restenosis in venous grafts, such as saphenous coronary bypass and peripheral arterial by-pass grafts.
Also provided by the present disclosure is a method of preventing VSMC accumulation and stenosis in arteriovenous fistulas used for dialysis access by transferring the E2F-1 gene.
Another method provided by the disclosure is the E2F-1 transfer to arteries and veins to reduce the primary formation of primary sclerotic lesions.
The foregoing has outlined rather broadly the features and advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features which are believed to be characteristic of the invention will be better understood from the following detailed description, in conjunction with the accompanying drawings.
FIG. 1. A & B: Transduction of E2F-1 into human vascular smooth muscle cells (VSMC). Human VSMC were infected for six hours with a mock control, Ad.RR and Ad.E2F-1 at a multiplicity of infection (MOI) of 50 and were immunostained for E2F-1. An example of VSMC stained 10 hours after infection with E2F-1 is shown in (panel A), whereas no immunoreactivity to E2F-1 was seen in Ad.RR infected cells harvested at the same time (panel B). Magnification 400×.
FIG. 2 . Ad.E2F-1 promotes S-phase entry in growth arrested human VSMC. VSMC were serum deprived for 48 hours and infected with growth arrest medium alone (mock control), Ad.E2F-1 or Ad.RR at MOI of 100 for 6 hours. The cells were kept for an additional 4 days in serum-deprived medium. Cells were harvested every 24 hours and analyzed by DNA flow cytometry. Shown is the percentage of cells in S-phase over time.
FIG. 3. A, B & C: S-Phase Entry of E2F-1 Transduced Coronary VSMC is Associated with Induction of Apoptosis. Shown are human coronary VSMC 36 hours after treatment with mock control (panel A); the null adenoviral vector, Ad.RR (panel B), and Ad.E2F-1 (panel C). Viral vectors were used at MOI 100; magnification 100×.
FIG. 4 . Apoptosis in VSMC infected with Ad.E2F-1. Frames 1-9 show the changes observed in a single cell from the sample of coronary VSMC transduced with E2F-1 (MOI 100). Surface blebbing and loss of membrane integrity with extrusion of cellular contents were nearly complete within 2 hours after the first changes were observed (30-32 hours post-infection).
FIG. 5. A & B: Dose Response and Time Course of Apoptosis in VSMC Infected with Ad.E2F-1. The VSMC were infected for six hours with Ad.E2F-1, Ad.RR or mock control at MOI 10-200 followed by growth stimulation in 10% FBS. VSMC were harvested every 24 hours and subjected to DNA flow cytometry. Panel A shows the flow cytometry profile of individual treatment groups subjected to different dosages of viral vectors. Panel B indicates the percentage of cells undergoing apoptosis, as reflected by hypodiploid, cleaved DNA after Ad.E2F-1 infection.
FIG. 6 . Growth suppression of VSMC after adenovirus-mediated E2F-1 gene transfer. Growth curves were established for human coronary VSMC by daily counts of serum stimulated Ad.E2F-1, Ad.RR, and mock infected VSMC in triplicates.
FIG. 7 . The influence of Ad.E2F-1 compared to control virus (Ad.RR) on the intima area, the media area, and the intima/media ratio 28 days after balloon injury in cholesterol-fed hypercholesterolemic New Zealand white rabbits.
FIG. 8 The influence of Ad.E2F-1 compared to control virus (Ad.RR) on the percentage of stenosed carotid arteries 28 days after balloon injury in cholesterol-fed hypercholesterolemic New Zealand white rabbits.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Vascular restenosis, a major unresolved problem for percutaneous coronary revascularization procedures, has thus far been resistant to all therapeutic strategies. The present disclosure describes a treatment strategy for restenosis which is directed toward interference with a specific cellular event that leads to neointimal formation, with a specific goal of decreasing the neointimal volume through apoptosis of proliferating VSMC.
The present invention reduces the number of VSMC at the site of vascular injury by inducing their coordinated death through E2F-1-induced apoptosis. This coordinated death of VSMC at the site of injury reduces neointimal formation by decreasing the number of VSMC available to migrate towards the lumen, to produce growth factors, and to produce extracellular matrix (Ohno et al., 1995, Chang et al., 1995). In contrast to the cell cycle arrest genes that limit VSMC growth by preventing entry of the cells into S-phase (Ohno et al., 1995, Chang et al., 1995), E2F-1 gene transfer drives the VSMC from G1 into S-phase, ultimately resulting in the apoptotic programmed death of the transformed VSMC.
Cloning and sequencing of the human E2F-1 cDNA
Extraction of mRNA from ML-1 cells was performed using the QIAGEN mRNA isolation kit (QIAGEN, Valencia, Calif.). First-strand cDNA was synthesized using superscript II RNase H-reverse transcriptase (Gibco BRL, Gaithersburg, Md.). E2F-1 sequences were prepared by polymerase chain reaction using rTth DNA polymerase XL (Perkin-Elmer,) along with the following primers:
Sequence 1
5′E2F 1_sense: 5′-CGTGAGCGTCATGGCCTTTG-3′ sense primer, SEQ ID NO: 1
Sequence 2
3′E2F 1_antisense: 5′-CCAAGCCCTGTCAGAAATCCA-3′ antisense primer, SEQ ID NO: 2 (primers were designed according to the E2F-1 sequence obtained from gene bank accession number M96577).
The polymerase chain reaction amplified fragment was cloned into pCR-Script vector, and positive clones were identified and sequenced. Double-stranded DNA sequencing was performed in the University of Texas Medical School Sequencing Core facility.
Recombinant adenovirus construction
The recombinant E2F-1 adenovirus (Ad.E2F-1) contains the human cytomegalovirus promoter, E2F-1 cDNA, and bovine growth hormone polyadenylation signal in a mini-gene cassette inserted into the E1-deleted region of modified adenovirus type 5 (Ad5). Replication-defective adenovirus carrying the human E2F-1 gene (Ad.E2F-1) was generated by cotransfecting the pXCJL-1 and pJM 17 plasmids, which were provided by Dr. F. L. Graham (Microbix Biosystems, Hamilton, Ontario), into 293 cells (McGrory et al., 1988). Viral stocks were propagated in 293 cells. Replication-defective adenovirus containing no foreign gene (Ad.RR) was a gift by Dr. Robert D. Gerard (Leuven, Belgium). Recombinant adenoviruses (Ad.E2F-1 and Ad.RR) were plaque-purified and purity of Ad.E2F-1 was established by immunoblotting for E2F-1 on VSMC infected with virions amplified from individual plaques. High titer adenovirus was purified from 293 cells with modification of a previously described procedure (Gomez-Foix et al., 1992). These modifications included a 30-min digestion of precipitated virions with benzonase (100 U/ml, American International Chemical, Inc., Natick, Mass.) and the addition of 2 sequential CsCl (density 1.34 mg/ml) equilibrium centrifugation steps at 180,000×g for 6 hours at 4° C. Purified recombinant virions were suspended in sucrose (2% w/vol) and MgCl 2 (2 mM) in PBS, desalted by sepharose CL4B exclusion chromatography (Pharmacia Corporation, Piscataway, N.J.), supplemented with 5% glycerol and stored at −80° C.
The concentration of infectious viral particles was determined in 293 cells by plaque assay as described in McGrory et al., 1988. All viral preparations were tested for endotoxin using a Limulus amebocyte lysate assay and were found to be endotoxin-free (<0.125 EU/ml).
Cell Culture
Human vascular smooth muscle cells (VSMC) were obtained for these studies from Dr. Timothy Scott-Burden (Texas Heart Institute). Passage 2 human coronary VSMC were purchased from Cascade Biologics, Inc. (Portland, Oreg.). Cells were grown in Dulbecco's modified Eagle's medium (DMEM) from Gibco or in Medium 231 from Cascade Biologics, Inc. For cell growth experiments, VSMC were seeded in triplicates at a density of approximately 10×10 3 /cm 2 and were growth arrested for 60 hours in DMEM supplemented with 0.1% bovine serum albumin or in Medium 231. For infection of the VSMC, recombinant adenovirus was suspended in the growth arrest medium (DMEM with 0.1% bovine serum albumin or Medium 231). Cells were then infected for six hours with either the replication-deficient adenovirus encoding the human E2F-1 gene (Ad.E2F-1), with a recombinant adenovirus carrying the identical CMV promoter but no transgene (empty virus, or Ad.RR), or with the growth arrest medium used for suspending the virus (mock control). Multiplicities of infections (MOI, number of infectious virions/number of cells) were from 10 to 200. After six hours, the virus suspension or control medium was removed, and cells were washed twice with DMEM and fed with DMEM supplemented with 10% fetal bovine serum. Cells were counted every 24 hours, using a Coulter counter (Model Z1, Coulter Inc.).
DNA Analysis by Flow Cytometry
Human VSMC were plated at approximately 3.5×10 5 cells/60mm tissue culture dish for 7 day experiments and growth arrested for 60 hours as described above (cell count was approximately 4.5×10 5 on the day of infection). Cell density was at approximately 6×10 5 /60 mm plate or 7.6×10 5 /100 mm plate on the day of infection for 4-day experiments. Cells were then infected for six hours at the indicated MOI with Ad.E2F-1, Ad.RR (empty control virus), or mock control (growth arrest medium) as described above. Following removal of the virus, cells were washed twice with DMEM and growth-stimulated with DMEM supplemented with 10% FBS. At 24-hour intervals, cells were harvested for cell cycle and apoptosis analyses by DNA flow cytometry. Each sample was collected by pooling together detached cells in medium, attached cells, and all PBS washes before and after trypsinization. Samples were centrifuged for 10 min at 1800 rpm and then resuspended in 0.2 ml of PBS, followed by dropwise addition of 5 ml of ice-cold 85% ethanol while vortexing gently. Fixed cells were stored at −200° C. until all samples were collected. On the day of analysis, samples were centrifuged at 2500 rpm for 10 min and the ethanol was decanted. Cells were then washed once with PBS, centrifuged at 3000 rpm for 10 min. Each sample was resuspended in 200 or 400 μL of 100-μg/mL propidium iodide with 50 μg/ml RNase and incubated at 37° C. for 20 min. At least 4×10 3 cells were analyzed on the Coulter EPICS® Profile instrument (Miami, Fla.). Histograms were stored and files analyzed using Multicycle program from Phoenix Flow Systems (San Diego, Calif.).
E2F-1 immunohistochemistry
In order to assess whether E2F-1 was expressed in the VSMC at a time preceding the appearance of cell changes typical of apoptosis, VSMC infected with Ad.E2F-1, Ad.RR, and mock control were immunostained beginning at the completion of the six-hour infection. A mouse monoclonal antibody reactive with human E2F-1 was used as primary antibody (Santa Cruz Biotechnology, Santa Cruz, Calif.). Antibody binding was visualized with DAB, using a biotinylated secondary antibody and a streptavidin-biotin-horseradish peroxidase kit (Vector, Burlingham, Calif.). PBS with 0.1% Triton X-100 was used to suspend the antibodies and for all washing steps. VSMC were plated into chamber slides (Nalgen Nunc Intl., Naperville, Ill.) and serum-deprived for 60 hours and infected for six hours with Ad.E2F-1, Ad.RR, or mock control, as described above. After six hours, the virus was removed and cells were washed twice with DMEM then growth-stimulated in DMEM supplemented with 10% FBS. Cells were washed twice with phosphate-buffered saline (PBS), fixed for 10 min in three parts methanol and one part acetone at −20° C., and immunostained for E2F-1. Cells were counterstained with Alcian blue/methyl green in PBS, dehydrated in ethanol and coverslipped with Cytoseal 60 mounting medium (Stephens Scientific, Riverdale, N.J.).
Microscopy
Cell morphology was evaluated by combined epifluorescence and differential interference contrast (DIC) microscopy. Briefly, cells were passaged to glass slides and kept in serum-free medium for 60 hours prior to treatment. After incubation with Ad.E2F-1, Ad.RR or growth arrest medium alone, cells were stimulated by addition of DMEM with 10% FBS. Thirty hours after infection, the cells were incubated in the dark at 37° C. with 10 μg/ml of Hoechst 33342 and 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (DASPMI) for staining of nuclear DNA and mitochondrial membranes, respectively. DNA staining and mitochondrial staining were, respectively, detected with a DAPI filter and a FITC filter set. All micrographs were digitally captured on a Zeiss Axioskop epifluorescence microscope using an Optronics (Goleta, Calif.) DEI-750 CCD color camera with Adobe Premiere software (Adobe Systems, Mountainview, Calif.), a TARGA 2000 video board (Truevision, Inc., Santa Clara, Calif.) and a PowerPC Macintosh 9500 (Apple Computer, Cupertino, Calif.). Images were edited with Adobe Photoshop software (Adobe Systems, Mountainview, Calif.).
Transduction of Human Vascular Smooth Muscle Cells (VSMC) with E2F-1
Growth-arrested human coronary VSMC were incubated at MOI 50 with Ad.E2F-1, Ad.RR, and mock control as described above and after various time periods processed for E2F-1 immunohistochemistry. Predominant nuclear E2F-1 immunostaining was present as early as 6 hours after start of infection as illustrated in FIG. 1A, or immediately after the removal of the Ad.E2F-1 in the transduced VSMC, whereas no staining was seen by 20 hours in control virus or mock treated cells (see FIG. 1 B).
Overexpression of E2F-1 Forces Serum-Deprived Coronary VSMC to Enter S-Phase
After demonstrating that E2F-1 was overexpressed in VSMC, DNA flow cytometry analysis of the cells was performed to verify that E2F-1 transfer had promoted S-phase entry of quiescent VSMC during growth arrest initiated by prolonged serum deprivation. Growth arrested cells were infected with Ad.RR, mock control and Ad.E2F-1 at MOI of 100, and kept in serum-free medium for an additional four days. Cells were harvested every 24 hours and processed for DNA flow cytometry. Despite prolonged serum deprivation, Ad.E2F-1 (but not Ad.RR or mock control) promoted S-phase entry in the quiescent VSMC, as shown by the flow cytometry results illustrated in FIG. 2 . In contrast, the percentage of VSMC in S-phase remained consistently below 5% in the Ad.RR and mock-treated cells.
S-Phase Entry of E2F-1 Transduced Coronary VSMC is Associated With Induction of Apoptosis
Within 24-36 hours after gene transfer of E2F-1 to VSMC, the induction of apoptosis was observed. Apoptotic changes, which were not observed after infection with the null adenoviral vector, Ad.RR, included membrane blebbing and loss of cytoplasmic membrane integrity, cell shrinkage and detachment, chromatin condensation, and loss of mitochondrial integrity ( see FIGS. 3A-3C and FIG. 4 ). Loss of mitochondrial membrane integrity was visualized with DASPMI, a mitochondrial membrane specific dye, as diffuse fluorescence alternating with areas of membrane condensation. Chromatin condensation and fragmentation were apparent as intensified fluorescence of nuclear fragments after staining with the intercalating DNA dye, Hoechst 33342.
The development of apoptosis induced by E2F-1 expression occurred in a relatively short-time frame, as shown by video time lapse microscopy. FIG. 4 frames 1-9 show in phase-contrast the changes observed in a single cell from a sample of coronary VSMC transduced with E2F-1 (MOI 100). Surface blebbing and loss of membrane integrity with extrusion of cellular contents were nearly complete within 2 hours after the first changes were observed (30-32 hours post-infection).
In order to evaluate time course and magnitude of apoptosis in coronary VSMC transduced with E2F-1, the cells were infected for six hours with Ad.E2F-1, Ad.RR, or mock control at MOI 10-200 followed by growth-stimulation in 10% FBS. The VSMC were harvested every 24 hours and subjected to DNA flow cytometry, which showed a dose-dependent induction of apoptosis by Ad.E2F-1, as reflected by the hypodiploid cell population in sub G 1 due to cleavage of DNA. Increases in the sub GO fraction were observed with dosages of Ad.E2F-1 as low as MOI 5 (FIG. 5 A). After the single application of Ad.E2F-1, induction of apoptosis involved a percentage of cells that appeared to increase over time. The sub G 1 fraction of VSMC peaked at 85% on day 5 with Ad.E2F-1 MOI 200 and at 17% on day 3 when a MOI of 10 was used, compared to respectively, 8% and 3%, with Ad.RR (FIG. 5 B).
Growth suppression of VSMC in vitro after adenovirus-mediated gene transfer
After observing that E2F-1 transduced VSMC undergo apoptosis, the rate of cell death by apoptosis and the rate of cell proliferation were determined to ascertain if E2F-1 gene transfer would inhibit net growth of cultured VSMC. Growth curves were established for human coronary VSMC, infected with Ad.E2F-1, Ad.RR, or mock control. When cell growth was followed for seven days, it was observed that gene transfer of E2F-1 reduced VSMC growth after infection at MOI 10 and completely abolished growth after infection at MOI of 100 and 200 (FIG. 6 ).
An addition set of quiescent VSMC were infected for 6 hours at multiplicity of infection 100 with an adenovirus (Ad) encoding human E2F-1 or a control virus without foreign gene (Ad.RR), followed by serum stimulation for 6 days. E2F-1 expression, by immunohistochemistry, was observed within 6 hours after exposure to Ad.E2F-1. Cell counts were performed in conjunction with DNA flow cytometry to estimate apoptosis. By 24 hours, Ad.E2F-1 induced apoptotic features, including chromatin condensation, membrane blebbing, and cell detachment. After 2 days, 31.2±0.7% (mean±SD) of Ad.E2F-1 treated cells had undergone apoptosis, as indicated by the fraction of cells in sub G1 on DNA flow cytometry, and this percentage increased to 43.6±0.1% on day 4. In contrast, only 1.8±0.6% and 5.37±0.4% of Ad.RR infected VSMC were in sub G1 phase at 2 and 4 days, respectively. On day 6, the sub G1 fraction of Ad.E2F-1 infected VSMC was still higher than that of Ad.RR infected cells (20.0±5.4 versus 6.5±1.3, p<0.001). Of the surviving (cycling) VSMC, the percentage in S-phase, measured daily, ranged from 22.4±2.9 to 30.1±4.5 in Ad.E2F-1 treated cells, whereas the cells in S-phase decreased to 3.2±0.3% in the Ad.RR infected cells. Daily counts of serum-stimulated VSMC showed an increase in cell number (in 103 cells/well, N=3) from 265±1.9 (quiescence) to 3,585±395 six days after infection with Ad.RR, whereas Ad.E2F-1 treated cells increased to only 312±54 (p<0.001 compared to Ad.RR). Thus, gene transfer of E2F-1 to human VSMC promoted S-phase entry and apoptosis and thereby markedly suppressed serum-dependent growth.
These in vitro studies establish that gene transfer of E2F-1 induces death of VSMC by inducing apoptosis and thereby reduces the proliferating VSMC mass. Induction of cell death will irreversibly eliminate the VSMC as a source of paracrine and autocrine growth factors and extracellular matrix, which significantly contribute to the pathogenesis of the restenotic lesion. In addition, any potential for intimal migration of VSMC is abrogated after the VSMC dies.
Influence of Ad.E2F-1 in an Atherosclerotic Animal Model
Under approved protocols, male New-Zealand rabbits (12 months of age) were fed for 28 days a 0.75% cholesterol-enriched chow and exhibited severe hypercholesterolemia. After this period, the rabbits were anesthetized, underwent transfemoral carotid balloon angioplasty, followed by a 30-min. local dwell-delivery of Ad.E2F-1 virus or control (Ad.RR) virus to the site of carotid balloon injury. Ad.RR was given to the balloon injured rabbits at 1×10 10 pfu/ml and Ad.E2F-1 was administered at 1×10 10 , 1×10 9 , and 3×10 8 pfu/ml. After balloon angioplasty and virus delivery, the animals were allowed to recover and were kept for 28 days after surgery on the cholesterol-enriched diet. Twenty-eight days after surgery, the animals were sacrificed, and were pressure-perfused with neutral-buffered formaldehyde using standard techniques. This model closely corresponds to the atherosclerosis model of Pollman and associates (Pollman et al., 1998). The injured and uninjured carotid arteries were harvested. Paraffin-embedded arterial segment sections were prepared every 2-mm, and were stained with the Verhoeft/Van Giessen (elastic) stain, followed by quantitative histomorphometry, using standard equipment. The administration of Ad.E2F-1 at 3×10 9 pfu/ml significantly reduced atherosclerotic lesion formation compared to control virus. In addition, the lesions in the E2F-1 (3×10 9 pfu/ml) treated animals appeared to be less lipid-rich. Yet plasma cholesterol in Ad.RR (1×10 10 pfu/ml) treated rabbits was 820±116 mg/dl and 988±324 mg/dl in Ad.E2F-1 (3×10 9 pfu/ml) treated animals.
These experiments were repeated in male and female New-Zealand rabbits as described below, where Ad.RR and Ad.E2F-1 were administered at the same dosage of 3×10 9 pfu/ml. Expression of adenovirally mediated foreign expression was demonstrated in balloon-injured carotid arteries by immunohistochemistry with antibodies recognizing E2F-1 (clone KH95, Santa Cruz Biotechnology, Inc.). Anesthesia was induced in rabbits of either sex with xylazine and ketamine and maintained with isofluorane in oxygen.
A left femoral cut-down was performed. After insertion of a 5-F sheet into the left femoral artery 150 units of unfractionated heparin, 150 units/kg, were given intravenously. Then, a 5-F balloon angioplasty catheter with a 20×2.5 mm balloon was introduced into the sheath and advanced over a 0.014 inch guide wire to the right common carotid artery. A carotid cut-down was performed and the position of the balloon was adjusted so that its center was at the level of the branching point of the common carotid artery. This internal carotid artery was tied off and marked the center of the balloon-injured segment. The balloon was inflated 5 times for 30 sec to 8 atm, with a 60 sec interval between inflations.
The catheter, with the balloon deflated under suction, was withdrawn to the caudal (proximal) end of the injured carotid segment, which was ligated temporarily with umbilical tape in a fashion that left included in the isolated vascular segment the proximal catheter tip. Then, the guide wire was removed from the animal. Through the opening of the wire lumen at the catheter tip 10 ml of physiological saline solution was introduced into the injured carotid segment to remove the blood in the injured segment. Then, the distal end of the injured carotid segment was temporarily ligated with a second umbilical tape. All remaining saline was removed from the isolated carotid segment and purified recombinant adenoviral vectors at 3×10 9 pfu/ml were introduced through the wire lumen of the angioplasty balloon catheter into the temporarily isolated lumen of injured carotid artery in an amount sufficient to barely distend the isolated segment. Ad.RR, the control vector, and Ad.E2F-1 were administered in the same manner. The suspension containing the adenoviral vectors were left in situ for 30 min, followed by their removal through the catheter. The umbilical tape was released and the catheter was withdrawn from the animal and the umbilical tape was removed from the injured carotid artery to allow return of blood flow into the carotid artery. The femoral and carotid cut-down was repaired and the rabbits were allowed to recover.
Dalteparin, 60 units/kg (Fragmin, Pharmacia & Upjohn, Kalamazoo, Michigan) was given every 12 hours for 2 doses, beginning 1 hour after angioplasty. Following removal of the catheter from the animal, the animals were returned to their cages and sacrificed 4 and 28 days after surgery, respectively, to confirm local expression of E2F-1 and to evaluate the site of injury for neointima formation.
Four days after surgery, some animals were sacrificed after pressure perfusion-fixation with 10% buffered formaldehyde. The balloon-injured carotid arteries were harvested and arterial rings were processed and embedded in paraffin using standard procedures. Following preparation of 5 μm sections, these were post-fixed for 15 minutes in 4% formaldehyde. After exposure for 10 minutes to 3% H 2 O 2 in methanol, the sections were blocked for 20 minutes in 2% horse serum in PBS and exposed for 1 hour at room temperature to a monoclonal antibody to human E2F-1 (clone KH95, Santa Cruz Biotechnology, Inc.) or cytomegalovirus (DAKO, Carpinteria, California) as negative control.
Sections were exposed for 30 min to a biotinylated horse antimouse antibody (VectorLabs) and incubated for 30 minutes in streptavidin-biotin-horse radish peroxidase (VectorLabs). Antibody binding was visualized by exposure to DAB (Vector Labs) and sections were counterstained in 1% Alcian blue and 2% methyl green (VectorLabs) or hematoxylin & eosin, using routine procedures. PBS was used for washes. These methods confirmed E2F-1 expression in rabbit carotid arteries treated with Ad-E2F-1 for 30 min.
Twenty-eight days after surgery, the rabbits were sedated and anesthetized with xylazine and ketamine. A carotid cut-down was performed on the side previously injured. Then, the animal was pressure perfusion-fixed with 10%-buffered formaldehyde and the injured carotid segment and a short segment of the contralateral carotid artery were harvested into 10%-buffered formaldehyde.
The arteries were cut in about 2 mm rings and, using routine histology procedures, embedded in paraffin. Several arterial rings were placed next to each other in each mold, facilitating later preparation and evaluation on sections from (2-mm) adjacent sampling sites of the same carotid segment. About 5-9 arterial rings were obtained from each injured carotid segment, allowing sampling of the same number of histomorphometric measurements per carotid segment. Sections used for histomorphometric analysis were stained with a Verhoeft-Van Gieson elastic stain and magnified images were captured using a Axiophot microscope (Zeiss, West Germany) and Lumina videocamera (Lumina, Lefs Systems, Co.). Images were processed with software from Optima Imaging Analysis Systems 4.1. Measurements were performed by a technician unaware of the treatment the rabbits had received.
The results of this histomorphometric analysis is shown in FIGS. 7 and 8 and indicate the gene transfer of E2F-1 at 3×10 9 pfu/ml markedly suppresses neointima/arteriosclerosis lesion formation in the Ad.E2F-1 treated rabbit arteries.
The success of the E2F-1 gene transfer to prevent primary atherosclerotic lesions in the rabbit model illustrates that gene transfer of E2F-1 can prevent atheromatous and fibroproliferative lesion formation in vivo despite severe elevation of cholesterol levels. Thus, E2F-1 gene transfer to arteries and vein grafts can be used to prevent or significantly reduce atherogenesis and fibroproliferative disorders in arteries, veins, grafts, arteriovenous fistulas and stent grafts.
While the preferred embodiment of the invention has been shown and described, modifications thereof can be made by one skilled in the art without departure from the spirit and teachings of the invention. The embodiment described herein is exemplary only and is not limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalent subject matter of the claims.
REFERENCES
The patents and technical publications referred to herein are incorporated by reference to the extent that they provide any necessary methods and materials not specifically set forth herein.
Agah, R., Kirshenbaum, L. A., Abdellatif, M., Truong, L. D., Chakraborty, S., Michael, L. H., Schneider, M. D. Adenoviral delivery of E2F-1 directs cell cycle reentry and p53-independent apoptosis in postmitotic adult myocardium in vivo. 1997. J Clin Invest; Dec 1 100(11):2722-2728
Chang, M. W., Barr, E., Seltzer, J., Jiang, Y-Q., Nabel, G. J., Nabel, E. G., Pannacek, M. S., Leiden, J. M. Cytostatic gene therapy for vascular proliferative disorders with a constitutively active form of the retinoblastoma gene product. 1995. Science; 267(5197):518-522.
Clowes, A. W., Reidy, M. A., Clowes, M. M. Kinetics of cellular proliferation after arterial injury. I. Smooth muscle growth in the absence of endothelium. 1983. Lab Invest; 49(3):327-333.
DeGregori, J., Leone, G., Alexander, M., Jakoi, L., Nevins, J. R. Distinct roles for E2F proteins in cell growth control and apoptosis. 1997. Proc Natl Acad Sci USA; Jul 8 94 (14): 7245-7250.
Fueyo, J., Gomez-Manzano, C., Yung, W. K. A., Liu, T. J., Alemany, R., McDonnell, T. J., Shi, X., Rao, J. S., Levin, V. A., Kyritsis, A. P. Overexpression of E2F-1 in glioma triggers apoptosis and suppresses tumor growth in vitro and in vivo. 1998. Nature Medicine; Jun 4 (6):685-690.
Gomez-Foix, A. M., Coats, W. S., Baque, S., Alam, T., Gerard, R. D., Newgard, C. B. Adenovirus-mediated transfer of the muscle glycogen phosphorylase gene into hepatocytes confers altered regulation of glycogen metabolism. 1992. J Biol Chem Dec 12 267(35):25129-25134.
Gordon, D., Reidy, M. A., Benditt, E. P., Schwartz, S. M. Cell proliferation in human coronary arteries. 1990. Proc Natl Acad Sci USA Jun 87 (12):4600-4604.
Griffith, T. S., Brunner, T., Fletcher, S. M., Green, D. R., and Ferguson, T. A. Fas ligand-induced apoptosis as a mechanism of immune privilege. 1995. Science, Nov 17 270(5239): 1189-1192.
Helin, K., Lees, J. A., Vidal, M., Dyson, N., Harlow, E., and Fattaey. A. A cDNA encoding a pRB-binding protein with properties of the transcription factor E2F. 1992. Cell 70:337-350.
Hunt, K. K., Deng, J., Liu, T. J., Wilson-Heiner, M., Swisher, S. G., Clayman, G., Hung, M. C. Adenovirus mediated overexpression of the transcription factor E2F-1 induces apoptosis in human breast and ovarian Carcinoma cell lines and does not require p53. 1997. Cancer Res Nov 1 57(21):4722-4726.
Johnson, D. G., Cress, W. D., Jakoi, L., and Nevins, J. R. Oncogenic capacity of the E2F-1 Gene. 1994. Proc. Natl. Acad. Sci. USA 91:12823-12827.
Kowalik, T. F., Degregori, J., Schwarz, J. K., and Nevins, J. R. E2F1 overexpression in quiescent fibroblasts leads to induction of cellular DNA synthesis and apoptosis. 1995. J Virol. 69:2491-2500.
Li, Y., Slansky, J. E., Myers, D. J., Drinkwater, N. R., Kaelin, W. G., Farnham, P. J. Cloning, chromosomal location, and characterization of mouse E2F1. 1994. Mol Cell Biol Mar 14(3):1861-1869.
McGrory, W. J., Bautista, D. S., Graham, F. A simple technique for the rescue of early region I mutations into human adenovirus type 5. 1988. Virology Apr 163(2):614-167.
Neuman, E., Sellers, W. R., McNeil, J. A., Lawrence, J. B., and Kaelin, Jr., W. G. Structure and partial genomic sequence of the human E2F1 gene. 1996. Gene Sep 16; 173(2):163-169.
Nevins, J. R. E2F: a link between the Rb tumor suppressor protein and viral oncoproteins. 1992. Science 258:424429.
O'Brien, E. R., Alpers, C. E., Stewart, D. K., Ferguson, M., Tran, N., Gordon, D., Benditt, E. P., Hinohara, T., Simpson, J. B., Schwartz, S. M. Proliferation in primary and restenotic coronary atherectomy tissue. Implications for antiproliferative therapy. 1993. Circ Res; Aug 7 73(2):223-231.
Ohno, T., Gordon, D., San, H., Pompili, V. J., Imperiale, M. J., Nabel, G. J., Nabel, E. G. Gene therapy for vascular smooth muscle cell proliferation after arterial injury. 1994. Science Aug 5 265(5173):781-784.
Pollman, M. J., Hall, J. L., Mann, M. J., Zhang, L., Gibbons, G. H. Inhibition of neointimal cell bc1-x expression induces apoptosis and regression of vascular disease. 1998. Nature Medicine; Feb 4(2):222-227.
Qin, X. Q., Livingston, D. M., Ewen, M., Sellers, W. R., Arany, Z., and Kaelin, W. G. The transcription factor E2F-1 is a downstream target of RB action. 1995. Mol. Cell BioL 15: 742-755.
Qin, X. Q., Livingston, D. M., Kaelin, W. G., Jr., and Adams, P. D. Deregulated transcription factor E2F-1 expression leads to S phase entry and p53-mediated apoptosis. 1994. Proc. Natl. Acad. Sci. USA 91: 10918-10922.
Sata, M., Perlman, H., Muruves, D. A., Silver, M., Ikebe, M., Libermann, T. A., Oettgen, P., Walsh, K. Fas ligand gene transfer to the vessel wall inhibits neointima formation and overrides the adenovirus-mediated T-cell response. 1998. Proc Nati Acad Sci USA; Feb 3 95(3):1213-1217.
Schwartz, R. S., Edwards, W. D., Huber, K. C., Antoniades, L. C., Bailey, K. R., Camrud, A. R., Jorgenson, M. A., Holmes, D. R., Jr., Coronary restenosis: prospects for solutions and new perspectives from a porcine model. 1993. Mayo Clin Proc; Jan 68(1):54-62.
Schwartz, S. M., deBlois, D., O'Brien, E. R. The intima: soil for atherosclerosis and restenosis. 1995. Circ Res; Sep 77(3):445-4465.
Schwartz, S. M., Reidy, M. A., deBlois, D. Factors important in arterial narrowing. 1996. J Hypertension Dec. 14 (5):S71-S81.
Shan, B. and Lee, W. H. Deregulated expression of E2F-1 induces S phase entry and leads to apoptosis. 1994. Mol. Cell Biol. 14:8166-8173.
Shan, B., Durfee, T., and Lee, W. H. Disruption of RB/E2F-1 interaction by single point mutations in E2F-1 enhances S phase entry and apoptosis. 1996. Proc. Natl. Acad. Sci. USA 93:679-684.
Singh, P., Wong, . H., and Hong, W. Overexpression of E2F-1 in rat embryo fibroblasts leads to neoplastic transformation. 1994. EMBO J. 13:3329-3338.
Xu, G., Livingston, D. M., and Krek, W. Multiple members of the E2F transcription factor family and the products of oncogenes. 1995. Proc. Natl. Acad Sci. USA 92:1357-1361.
Yonemitsu, Y., Kaneda, Y., Hata, Y., Nakashima, Y., Sueishi, K. Wild-type p53 gene transfer: a novel therapeutic strategy for neointima hyperplasia after arterial injury. 1997. Ann NY Acad Sci Apr. 15 811:395-400.
2
1
19
DNA
Homo sapiens
1
cgtgagcgtc atggccttg 19
2
21
DNA
Homo sapiens
2
ccaagccctg tcagaaatcc a 21
|
Methods for induction of E2F-1 related vascular smooth muscle cell (VSMC) death to limit vascular stenosis or restenosis, to regress atherosclerotic plaque and to prevent atherogenesis are disclosed. Also disclosed is an adenovirus vector containing the E2F-1 gene, and a method of transferring the gene to a vessel or graft. A method of limiting cell proliferation and/or reducing cell numbers includes transferring the E2F-1 gene into VSMC to achieve overexpression of E2F-1 gene product, which drives vascular cells into S-phase and thereby causes their subsequent death.
| 2
|
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.
BACKGROUND OF THE INVENTION
This invention relates generally to temperature sensing devices, and, more particularly to a temperature sensing device which is capable of providing substantially instantaneous response to temperature changes.
There are many requirements for a temperature sensing device which is capable of substantially instantaneously providing an indication of temperature changes. For example, the operation of many currently available jet engines is directly linked to variations in temperatures in various parts of the engine. In the F101 jet engine, the entire control thereof is accomplished by the engine automatically responding to the pilot's command and specific parameters measured by the engine control system.
The engine control system regulates three engine parameters which are influenced by the temperature of the air entering the compressor of the engine. These parameters are engine speed, compressor variable stator vane position and acceleration fuel flow. Each of these three fundamental engine parameters is greatly affected by compressor inlet temperature. If, during engine transient operation the temperature sensor cannot vary its temperature signal output as rapidly as the actual temperature variances, the control system of the engine will incorrectly schedule the three parameters noted above.
The effect of an error in sensed compressor inlet temperature has the greatest impact upon compressor stator vane scheduling and thus the stall margin of the compressor. For example, at a mid range operating point, a 10° F. sensed error can result in the stators being 0.8 degrees off schedule. This is 50% of the entire tolerance band for the entire control system and engine. Thus it is evident that if the air temperature is changing at a rate of 100° F. per second, the temperature sensor must be extremely quick reacting or the engine must be very tolerant of scheduling errors. For high performance aircraft, however, neither of the above statements is true.
The speed at which a temperature sensor can sense a change in air temperature is generally proportional to the density of the air passing over the sensor. The response of the sensor to a step change in air pressure is called the "time constant". This means that with an instantaneous change in temperature (a step input), the sensor output will be approximately 63% of the change in one time constant. At a typical idle condition (20 lb/sec/sq ft) it takes one second for the sensor to respond to only 63% of the real temperature change. Consequently, this is a major limiting feature in the acceleration of a jet engine. Therefore, with a sensor capable of reacting almost instantaneous with a temperature change, the jet engine could accelerate substantially faster.
It is therefore apparent that a temperature sensing device capable of substantially instantaneously providing an output indicative of temperature changes would be extremely beneficial in increasing the efficiency of jet engines or, for that matter, any other device which is dependent upon such temperature changes for its operation. Unfortunately, such sensors are currently unavailable since not only must these sensors respond rapidly to temperature changes, they must also (1) be able to mechanically survive the jet engine operating environment; (2) sense the steady state temperature within the accuracy required for the control system of the jet engine (this requirement is 1.0% per degree Rankine; and (3) respond to a change in compressor inlet temperature rapidly enough such that the resulting errors in sensor output do not result in engine parameter scheduling errors which are detrimental to the engine operation. In other words, such a sensor must be strong, accurate and fast. Unfortunately, from a design and mechanization standpoint, the requirement that the sensor be strong is in opposition to the requirement that the sensor be fast; that is, a large mass takes substantially more heat (BTU's) to change its temperature than a small mass.
SUMMARY OF THE INVENTION
The instant invention overcomes the problems encountered in the past by providing a compensated temperature sensing device which is extremely sensitive to changes in surrounding temperature.
The temperature sensor of this invention is made up of two sections, a bulb section and a transducer. The bulb section is placed in the area for which the temperature is to be sensed. This bulb is filled with a pressurized gas such as helium. As the helium in the sensing bulb is heated or cooled, its pressure level changes. The pressure level of the bulb is transmitted through a small tube into a bellows in the transducer section of the sensor. Within the transducer section, the pressure level of the helium pushes against the bellows, with the force required to resist that push being proportional to the temperature of the helium. The sensor changes the bellows force level to a hydraulic pressure level which is then used by a system, such as an engine control system, associated with the sensor for scheduling.
In order to substantially increase the response time of the sensor, the sensor of this invention heats the helium within the bulb or bellows faster than the heat can be conducted through the walls of the bulb. This is accomplished by providing an electrical heating element within the bellows in order to supplement the heat coming through the walls of the bulb. The amount of heat to be added to the bellows is dependent upon (1) the error in the sensed to actual air temperature and (2) the mass of the sensor which needs to have its temperature level changed.
It is therefore an object of this invention to provide a temperature sensing device which is capable of substantially instantaneously providing an output indicative of surrounding temperature changes.
It is another object of this invention to provide a compensated temperature sensing device which will allow the thin material bulb of past sensors to be replaced with a thicker more rugged bulb.
It is a further object of this invention to provide a compensated temperature sensing device which is more durable than past sensors.
It is a still further object of this invention to provide a compensated temperature sensing device which is economical to produce and which utilizes conventional, currently available components that lend themselves to standard mass producing manufacturing techniques.
For a better understanding of the present invention together with other and further objects thereof, reference is made to the following description taken in conjunction with the accompanying drawing and its scope will be pointed out in the appended claims.
DETAILED DESCRIPTION OF THE DRAWING
The only FIGURE of the drawing is a side elevational view of the compensated temperature sensing device of this invention shown partly in cross section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is now made to the only FIGURE of the drawing which shows in a side elevational view and partly in cross section the compensated temperature sensing device 10 of this invention. Temperature sensing device 10 although primarily utilized for providing a signal indicative of variances in temperature within the compressor inlet of a jet engine (not shown), temperature sensing device can be utilized with any system in which an output indicative of temperature variations is to be sensed.
Compensated temperature sensing device 10 is made up of a transducer section 11 and a bulb section 12. The transducer section 12 is formed within a housing 13 having a pair of chambers 14 and 16 therein interconnected by a metering orifice 15. Chamber 14 is connected by means of a hydraulic input port 18 to any suitable source of hydraulic fluid (not shown) which supplies hydraulic fluid to chambers 14 and 16. Chamber 16 is interconnected by way of hydraulic output port 20 to any suitable device (not shown) which is capable of receiving a signal in accordance with a change of pressure. The pressure between chambers 14 and 16 is regulated by the position of a metering element 22 in the form of, for example, a tapered member mounted within metering orifice 15.
Metering element 22 is affixed at one end thereof to a bellows 24 situated within chamber 14. The other end of metering element 22 is affixed by means of an extension rod 26 to another bellows 28 located within chamber 16. Additionally, any suitable biasing means such as spring 29 is interposed between bellows 28 and an upper wall 31 of chamber 16. The pressure applied to evacuated bellows 24 produces a net force which combined with spring 29 acts as a countering force to the change in position of bellows 28.
Bulb section 12 is affixed to housing 13 and includes a temperature sensing bulb 30 in the form of a coiled tubular element. Bulb 30 is affixed by means of a tube 32 to chamber 16 of housing 13. This is accomplished by tube 32 being in alignment with a port 34 within housing 13. Port 34 directly connects the interior of bellows 28 to the interior of bulb 30.
The bulb section 12, although being depicted directly adjacent housing 13 can be extended therefrom, if desired, and placed in the area in which the temperature is to be sensed. For example, bulb section 12 may be placed in the air flow path upstream of the compressor inlet of a jet engine.
Bulb 30 is generally made of a zirconium tube approximately 7 inches long, 1/4 inches in outer diameter with 0.007 inch wall thickness and bent into the shape of a coil. Bulb 30 is filled with pressurized helium. The purpose of using zirconium for the bulb material is that it has the lowest value of density and specific heat of any known structural material. That is, it requires the lowest number of BTU's to heat it from one value to another. Similarly, the helium is utilized since it has the highest conductivity of any known gas. This combination produces a fast response bulb.
Unfortunately, even such a response may be inadequate for the desired purpose of controlling a jet engine. Therefore an additional heat source, in the form of a resistance heater element or electrical heating coil 36 is situated within bellows 28. Heater element 36 is controlled by any suitable source of electricity formed as part of a conventional power source and control 38 operably connected thereto.
Since the geometry and metalurgical properties of zirconium require that the coil or bulb 30 be epoxied rather than welded, brazed or soldered in place, and since epoxy has a finite temperature limit which is near the operating temperatures experienced in, for example, a jet engine, the utilization of heating element 36 as in this invention removes the need for limiting the bulb material to zirconium. Consequently, if desired, bulb 30 can be manufactured from normal stainless steel which has conventional welding properties.
Referring more specifically now to the operation of the compensated temperature sensing device 10 of this invention, as the helium in sensing bulb 30 is heated or cooled by the surrounding temperature, its pressure level changes. The helium is contained in an almost constant volume. The pressure level of bulb 30 is transmitted through tube 32 and port 34 into bellows 28 in transducer section 11 of temperature sensing device 10. The pressure level of the helium within bellows 28 and bulb 30 pushes bellows 28 against spring 29 and bellows 24. The force required to resist that push is proportional to the temperature of the helium.
The positioning of bellows 28 alters the positioning of metering element 22 within metering orifice 15 and therefore regulates the flow of fluid through metering orifice 15. The hydraulic pressure level registered between output port 18 and 20 is indicative of the temperature change and can be utilized for controlling an aircraft or other device or system operably connected to the temperature sensing device 10 of this invention.
When an increase in air temperature surrounding bulb 30 occurs, the time constant of the temperature sensing device 10 can be decreased by adding supplemental heat inside bellows 28 by heating element 36. The pressure in the bellows 28 increases because sensing bulb 30 is getting hotter and supplemental heat is being supplied within bellows 28. As the pressure increases in bellows 28, it expands and reduces the area of metering orifice 15. This increases the hydraulic pressure drop and that pressure is sensed by an engine control system, for example, as an increase in air temperature.
The amount of heat to be added to the temperature sensing device 10 of this invention is dependent upon the error in the sensed to actual temperature and the mass of the sensor. The transducer section 11 of sensor 10 does not need to be at the same temperature level as bulb section 12. Also, the amount of heat needed to be added internally to the helium within sensor 10 can be approximated in a number of ways. For example, in a jet engine, the amount of heat added may be dependent upon change in power lever angle, rate of change of the helium pressure level, engine speed error or an arbitrary input.
Although the above discussion of this invention refers to a compensated temperature sensing device 10 in which it is essential to speed up the sensor in the increasing temperature direction, the temperature sensing device 10 of this invention can also be used to speed up the sensor in the decreasing temperature direction. This is accomplished by supplying supplemental heat even during steady state operation. Thus bulb 30 is always hotter than ambient temperature. To speed up sensing a change in temperature in the decreasing direction, it is merely necessary to turn off the supplementary heat source 38.
Although this invention has been described with reference to a particular embodiment, it will be understood to those skilled in the art that this invention is also capable of further and other embodiments within the spirit and scope of the appended claims.
|
A compensated temperature sensing device having a sensing element capable of surviving extreme operating environments while still being able to substantially instantaneously sense temperature changes. This is accomplished by incorporating within the device an auxilliary heat source which artificially heats the sensing gas within the sensing device. The amount of heat added to the device would be dependent upon the error in the sensed to actual temperature and the mass of the sensor which requires a change in temperature level.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the priority of PCT Patent Application No. PCT/US11/30165 filed Mar. 28, 2011, entitled ENGINEERING OF AN ULTRA-THIN MOLECULAR SUPERCONDUCTOR BY CHARGE TRANSFER which claims the priority of U.S. Provisional Application Ser. No. 61/317,810 filed Mar. 26, 2010.
STATEMENT REGARDING FEDERALLY FUNDED RESEARCH
This invention was made with government support under Grant Number DE-FG02-02ER46012 awarded by the United States Department of Energy, Basic Energy Sciences. The government has certain rights in the invention.
FIELD
The invention relates generally to superconductive articles, and more specifically methods for forming superconductive articles.
BACKGROUND
“Organic” superconductors are part of the organic conductor family which includes molecular salts, polymers and pure carbon systems (including carbon nanotubes and C 60 compounds). The molecular salts within this family are large organic molecules that exhibit superconducting properties at very low temperatures. For this reason they are often referred to as “molecular” superconductors. Their existence was theorized in 1964 by Bill Little of Stanford University. But the first organic superconductor (TMTSF) 2 P 6 was not actually synthesized until 1980 by Danish researcher Klaus Bechgaard of the University of Copenhagen and French team members D. Jerome, A. Mazaud, and M. Ribault. About 50 organic superconductors have since been found with T c 's extending from 0.4 K to near 12 K (at ambient pressure). Since theses T c 's are in the range of Type I superconductors, engineers have yet to find a practical application for them. However, their rather unusual properties have made them the focus of intense research. These properties include giant magnetoresistance, rapid oscillations, quantum hall effect, and more (similar to the behavior of InAs and InSb). In early 1997, it was, in fact (TMTSF) 2 PF 6 that a research team at SUNY discovered could resist “quenching” up to a magnetic field strength of 6 tesla. Ordinarily, magnetic fields a fraction as strong will completely kill superconductivity in a material.
Organic superconductors are composed of an electron donor (the planar organic molecule) and an electron acceptor (a non-organic anion). A few examples of organic superconductors include:
(TMTSF) 2 ClO 4 [tetramethyltraselenafulvalene+acceptor] (BETS) 2 GaC 14 [bis(ethylenedithio)tetraselenafulvalene+acceptor] (BEDO-TTF) 2 ReO 4 H 2 O [bis(ethylenedioxy)tetrathiafulvalene+acceptor]
How small can a sample of superconducting material be and still display superconductivity? This question is relevant to the fundamental understanding of superconductivity, and also to applications in nanoscale electronics, because Joule heating of interconnecting wires is a major problem in nano-scale devices. It has been shown that ultrathin layers of metal can display superconductivity, but any limits on the size of superconducting systems remain a mystery. (BETS) 2 GaCl 4 , where BETS is bis(ethylenedithio)tetraselenafulvalene, is an organic superconductor, and in bulk it has a superconducting transition temperature Tc of ˜8 K and a two-dimensional layered structure that is reminiscent of the high-Tc cuprate superconductors.
Organic superconductors are regarded as unconventional superconductors because their properties cannot be explained by the Bardeen-Cooper-Schrieffer (BCS) theory that describes low-temperature superconductors such as lead and bismuth. Although scanning probe methods have provided unprecedented real-space information on both low-Tc BCS superconductors and high-Tc cuprate superconductors, there have only been a handful of reports of scanning tunneling spectroscopy measurements on layered organic superconductors. Moreover, direct visualization of the detailed molecular structures and local spectroscopic mapping of these systems has not yet been performed.
SUMMARY
Using scanning tunneling spectroscopy, it can be shown that a single layer of (BETS) 2 GaCl 4 molecules on an Ag(111) surface displays a superconducting gap that increases exponentially with the length of the molecular chain. Moreover, we show that a superconducting gap can still be detected for just four pairs of (BETS) 2 GaCl 4 molecules. Real-space spectroscopic images directly visualize the chains of BETS molecules as the origin of the superconductivity.
BRIEF DESCRIPTION OF THE DRAWINGS
To the accomplishment of the foregoing and related ends, the following description and annexed drawings set forth certain illustrative aspects and implementations. These are indicative of but a few of the various ways in which one or more aspects may be employed. Other aspects, advantages, and novel features of the disclosure will become apparent from the following detailed description when considered in conjunction with the annexed drawings.
FIG. 1 illustrates individual chemical structures of BETS (top 1A and side 1B views) and GaCl 4 (1C.)
FIG. 2 is an STM (Scanning Tunneling Microscope) image illustrating a monolayer thick (BETS) 2 GaCl 4 layer on Ag(111) (87×87 nm 2 , V t =0.6V, l t =8.6×10 −10 A).
FIG. 3 is an STM image of a λ-(BETS) 2 GaCl 4 molecular layer, revealing a double stacked BETS row, together with an unfinished packing of the first layer of BETS and GaCl 4 at the edge (V t =0.6V, l t =8.6×10 −10 A).
FIG. 4 is an STM image illustrating BETS molecules with bent edges (V t =0.1V, l t =6.8×10 −10 A).
FIG. 5 is a contrast-adjusted STM image illustrating the GaCl 4 locations between the BETS chains as protrusions. A GaCl 4 molecule is indicated (V t =15 mV, l t =1.0×10 −10 A).
FIG. 6 is a model illustrating the molecular packing on Ag(111).
FIG. 7 illustrates calculated DOS for λ-(BETS) 2 GaCl 4 , revealing that the charge near the Fermi level is mainly contributed by the BETS.
FIG. 8 illustrates a dI/dV curve showing a superconducting gap with a corresponding fit.
FIG. 9 illustrates the superconducting gap gradually disappearing as the temperature is increased from 5.8K to 15K.
FIG. 10 illustrates the superconducting gap decreasing as the temperature is increased. The error bars indicate the statistical distribution of gaps in different measurements.
FIG. 11 is an STM image illustrating shorter molecular chains at the centre.
FIG. 12 illustrates the superconducting gap as a function of molecular units with the error bar indicating the statistical distribution of gaps in different measurements. The inset illustrates the molecular chains with 4, 5, 8, 13 and 15 units; the 31 and 46 unit chains are too large to be illustrated. The right inset illustrates the dl/dV data corresponding to these molecular chains.
FIGS. 13-15 are STM images of the superconducting gap with (13) and (14) (V t =26 mV, l t =6.8×10 −10 A), and (15) (V t =−2 mV, l t =6.8×10 −10 A).
FIG. 16 a layout of an apparatus for use in connection with the deposition of a superconductor layer according to an embodiment of the invention.
FIG. 17 illustrates an x-ray diffraction pattern of custom-synthesized λ-(BETS) 2 GaCl 4 crystals. The x-ray diffraction measurements were carried out at room temperature using a Rigaku AFC7R diffractometer. Peaks in the diffraction pattern indicate a triclinic crystal structure with a unit cell shown in FIG. 18 . The BETS molecules (donors) are stacked along ‘a’ and ‘c’ axes, and the GaCl 4 molecules (acceptors) are located between the BETS chains.
FIG. 18 illustrates the crystal structure of λ-(BETS) 2 GaCl 4 crystals.
FIGS. 19( a ) and 19( b ) illustrate superconducting curve fittings for (a) d x 2 −y 2 and (b) d xy symmetries. The best fit is the orange curve in the d xy symmetry, and the corresponding T □ and Δ□ values are indicated with a rectangle in (b).
FIG. 20( a ) is an STM images illustrating (a) two BETS chains with GaCl 4 in between [Vt=0.6V, It=8.6×10-10A], and 20(b), the superconducting gaps measured on BETS and GaCl 4 locations indicated in (a) as ‘1’ and ‘2’, respectively.
FIG. 21 is an STM image illustrating λ-(BETS) 2 GaCl 4 molecular layer on Ag(111). The orientation of nodal and anti-nodal directions with respect to the BETS chains are indicated with white arrows. The dark arrows indicate the crystallographic ‘a’ and ‘b’ directions.
FIGS. 22( a ) and 22( b ) illustrate I-V tunneling spectroscopy curves of superconducting (a), and metallic (b) states.
FIG. 23 is an STM image illustrating a smaller cluster containing three molecular chains [Vt=0.6V, It=8.6×10-10A].
FIG. 24 illustrates the averaged dl/dV data showing superconducting gaps correspond to the chains, ‘L’ and ‘S’.
DETAILED DESCRIPTION
One or more aspects of the invention are described with reference to the drawings, wherein like reference numerals are generally utilized to refer to like elements throughout, and wherein the various structures are not necessarily drawn to scale. It will be appreciated that where like acts, events, elements, layers, structures, etc. are reproduced; subsequent (redundant) discussions of the same may be omitted for the sake of brevity. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects of the present invention. It may be evident, however, to one of ordinary skill in the art that one or more aspects of the invention may be practiced with a lesser degree of these specific details. In other instances, known structures are shown in diagrammatic form in order to facilitate describing one or more aspects of the invention.
The invention comprises an ultra-thin (BETS) 2 -GaCl 4 molecular superconductor composed of a single sheet of molecular layer having individual GaCl 4 sandwiched between chains of a double domino stacked BETS on a Ag(111) surface.
The two-dimensional planes in the λ-phase of (BETS) 2 GaCl 4 contain GaCl 4 molecules ( FIG. 1 ) that accept electric charge. They are sandwiched between layers of BETS (bis(ethylenedithio)tetraselenafulvalene)-molecules that donate electric charge. A custom-built evaporator for the vacuum deposition of sub-monolayer coverages of λ-(BETS) 2 GaCl 4 molecules on a clean Ag(111) substrate was utilized. The samples were subsequently cooled to liquid-helium temperatures in an ultrahigh vacuum (UHV) environment. Scanning tunneling microscope (STM) images acquired using a custom-built low-temperature UHV-STM system at 5.4 K reveal molecular islands having a single sheet of molecule packing thickness and exposed bare Ag(111) surface areas ( FIG. 2 ). Partial packing arrangements of molecules at the edges of the molecular islands ( FIG. 3 ), predominantly the first layer organization of BETS and GaCl 4 , indicate that the molecules diffuse and rearrange on the surface upon deposition. The intricate molecular packing arrangement can be observed in STM images of the molecular layer and at the edges of the islands ( FIGS. 3-5 ). The molecular packing arrangement ( FIG. 6 ) was established to be as follows. The double-stacked BETS form long chains along surface close-packed directions 8.7 Å (Angstroms) apart, and the top BETS are shifted laterally between the bottom BETS. This BETS arrangement is the same as that found in bulk crystals ( FIG. 18 ). The GaCl 4 molecules are located between the BETS chains, and are also spaced 8.7 Å (Angstroms) apart as in the λ-phase (BETS) 2 GaCl 4 crystal. Thus, the observed surface packing of (BETS) 2 GaCl 4 in the molecular clusters mimics the packing in their bulk counterpart. In the ordered molecular chains, the molecules have the correct ratio, that is, two BETS for each GaCl 4 . More importantly, the edges of the top BETS appear bent ( FIG. 4 ), reminiscent of the gas-phase BETS structure ( FIG. 1 ). For such bent edges to appear, the BETS need to align with their rings perpendicular to the surface. Here, the highest intensity of BETS appears around the position of the sulphur atoms of the two end p-rings. In this location, the molecule surface interaction should be considerably weakened but the molecule-to-molecule binding should be strengthened.
In D 2 A-type organic superconductors (D=donor, A=acceptor), the two donors transfer a total of one electron to the acceptor, resulting in the donors each having a half-filled electronic orbital, which is crucial for the superconducting transition below a critical temperature. Indeed, our density functional theory (DFT) calculation for a bulk λ-(BETS) 2 GaCl 4 system, using a generalized gradient approximation within the Perdew-Burke-Ernzerhof scheme and a plane wave basis set, reveals a transfer of 0.9 electronic charge from a BETS dimer to a GaCl 4 . Near the Fermi level, however, the charge is mainly located at the BETS, and only a small amount of charge is contributed from GaCl 4 at the low-lying states ( FIG. 7 ). This is apparent in the STM images, where the GaCl 4 between the BETS chains have much lower tunneling current intensities ( FIG. 5 ).
A robust superconducting gap is observed on the top BETS layer inside ordered molecular clusters ( FIG. 8 ) when the tunneling spectroscopy data are taken with a higher energy resolution (an a.c. modulation of 0.2 mV, 700-860 Hz). The average measured super conducting gap at 5.4 K is approximately 12 meV and the two maxima near the gap edges are also resolved. This is in agreement with the tunneling spectroscopy of the non-BCS-type bulk molecular superconductors, which exhibit a larger gap than typical BCS superconductors. There is debate over the nature of superconductivity in the organic salts regarding whether it has a d or an s wave pairing symmetry. In an s wave state, the superconducting gap is finite at every point on the Fermi surface. It is, therefore, observed with the gap flat across the bottom. In the d wave state, however, the DOS is anisotropic on the Fermi surface and linearly increases when moving away from the Fermi energy, giving a distinct V-shape to the gap. The λ-(BETS) 2 GaCl 4 has a triclinic crystal structure. Based on the shape of the first Brillouin zone of (BETS) 2 GaCl 4 , particular regions of momentum space have more weight than others, and therefore the contribution to the tunneling current will have an angular dependence in k space. The best fits for the measured superconducting gaps were achieved by using a d xy symmetry ( FIG. 8 ), and the nodal direction is oriented parallel to the a lattice vector between the BETS chains. The phenomenological formula
ⅆ I ⅆ V ∝ ∫ 0 2 π ∫ - ∞ ∞ Re [ E - ⅈ Γ ( E - ⅈ Γ ) 2 - ( Δ sin 2 θ ) 2 ] · f ( θ ) ⅆ E ⅆ θ
was used for curve fitting. Here, T is the lifetime broadening, Δ is associated with the energy gap, and θ is the azimuthal angle in k space. The weighting function f(θ) is taken as f(θ)=1+α cos 4θ, where α is a directionality constant.
Referring to FIGS. 19( a ) and ( b ) , the superconducting curve fits were performed by using the formula:
ⅆ I ⅆ V ∝ ∫ 0 2 π ∫ - ∞ ∞ Re [ E - ⅈ Γ ( E - ⅈ Γ ) 2 - Δ 0 2 ] · f ( θ ) · ⅆ E ⅆ θ
where Δ 0 =Δ cos 2θ, and Δ 0 =Δ sin 2θ were used for the d x 2 −y 2 □ and d xy symmetries, respectively. The best curve fit was obtained using d xy symmetry with θ approximately π/4, 2Δ=12 meV, and T=0.6.
Next, to confirm the observed superconductivity, the superconductor-metal transition was explored by varying the sample temperature. A sequence of dl/dV curves measured over a single large molecular island at different temperatures ( FIG. 9 ) shows that the edge state of the superconducting gap can be clearly observed up to 8 K. When the temperature is raised to 9 K, the superconducting gap is still observed, but the edge states start to disappear. The gap is no longer visible above 10 K. At 15 K, the I-V curve of the sample simultaneously recorded with the dl/dV signal reveals a metallic behaviour without any gap state ( FIGS. 22( a ) and 22( b ) ). A corresponding plot of the superconducting gap as a function of temperature is illustrated in FIG. 10 . The deduced 2Δ/kT c value for this system is approximately 13.6. The 2Δ/kT c values of anisotropic molecular superconductors are known to be larger than the BCS value of 3.52.
I-V and dl/dV-V tunneling spectroscopy data of molecular chains were simultaneously recorded (using a Stanford Instrument SR830 Lock-In Amplifier for the latter case) at different temperatures but at the same locations. I-V curves of molecular chains at 5.8 K exhibit a superconducting gap state around the Fermi energy, i.e. 0 mV ( FIG. 22( a ) ). When the temperature was raised, this gap state disappeared in the I-V data ( FIG. 22( b ) ). The I-V curve at 15K ( FIG. 22( b ) ) shows a continuous increase of current as the bias is increased, indicating a metallic character.
The question of the minimum size of the super conducting system was addressed. The results reported so far have been obtained from large molecular islands containing a number of molecular chains more than 100 nm long, and all had similar values of the superconducting gap. Isolated molecular chains, together with unfinished packing of the BETS and GaCl 4 , can be found in the smaller molecular islands ( FIG. 11 ). The ordered molecular chains in these islands still exhibit the superconducting gap, and for chains with lengths below 50 nm it was found that the superconducting gap decreases as the chains become shorter ( FIG. 12 ). Moreover, a small superconducting gap can still be detected in chains that contain just four (BETS) 2 GaCl 4 molecules. These chains have a length of approximately 3.5 nm along the BETS chain, which is in the crystallographic ‘a’ direction ( FIGS. 18, 21 ). The anisotropic coherence lengths of bulk λ-(BETS) 2 GaCl 4 are reported as 1.6 nm for the b* direction, and 12.5 nm each for the a* and c directions. These values are comparable by order with our findings. The exponential dependence of the superconducting gap on the chain length indicates that it is dominated by the coherence length within the molecular layer perpendicular to the tunneling direction.
The superconducting gap can be detected ubiquitously throughout the ordered BETS chains in large molecular islands. A sequence of real-space and spectroscopic images, shown in FIGS. 13-15 , provides further insight into the spatial distribution of the observed super-conductivity. The spectroscopic map acquired outside the gap shows that the ends of the BETS have a relatively higher intensity ( FIG. 14 ). In the λ-(BETS) 2 GaCl 4 phase, the GaCl 4 molecule is closer to one side of the BETS than the other. This effect can be clearly observed in FIG. 14 , where BETS molecules show charge asymmetry; that is, the charge density is more enhanced at one end of the molecule than the other. When the tunneling electron energy is tuned into the gap region, at −2 meV ( FIG. 15 ), the charge density is smeared along the BETS dimers. This spectroscopic image provides direct evidence that the superconducting sites originate in the BETS chains. Remarkably, the spectroscopic images reveal a nanoscale electronic order over the entire island. This further suggests that the coupling between intra-molecular electrons remains strong down to a single sheet of molecular packing rather than a relatively weak molecule-substrate binding.
The dl/dV-V tunneling spectroscopy data of smaller molecular islands on Ag(111) reveal that the superconducting gap is not uniform across the islands, but it is dependent on the length of the molecular chains. FIG. 23 presents an example case. Here, the shorter chain having 12 molecular units is labeled ‘S’ while a longer chain located next to it composed of 14 molecular units is marked as ‘L’. The dl/dV data acquired on these two chains are illustrated in FIG. 24 . Both molecular chains exhibit a superconducting gap however the longer chain has a ˜7 mV gap while the neighboring shorter chain has a ˜6 mV gap. Therefore, the superconducting gap observed here is dependent on the chain length.
Site dependent superconducting gaps were determined by positioning the STM tip on top of the BETS molecules and on the GaCl 4 located between the two BETS chains as indicated in FIG. 20 a . The dI/dV-V tunneling spectroscopy data exhibit a superconducting gap together with the two edge states on BETS chains. A superconducting gap state is still observed on GaCl 4 however, the two edge states in the gap have disappeared ( FIG. 20( b ) ).
Referring to FIG. 21 , the nodal direction is oriented parallel to the ‘a’ lattice vector and located between the chains as shown in FIG. 21 . At these locations the superconducting coherence peaks are minimized. The antinodal states are located on top of the BETS molecules making a 45° orientation with the nodal direction.
According to an embodiment of the invention, fabrication of a superconductive article begins with provision of a substrate. The substrate is generally metal-based and typically comprises a single crystal Ag(III) substrate. However, any type of material can be used.
Turning to FIG. 16 , there is illustrated a layout of an apparatus 100 for use in connection with the deposition of a superconductor layer by the process described below. Apparatus includes evaporator unit that is attached to load lock chamber 101 . Evaporator unit includes a Ta capsule to hold source molecules, a resistive heating filament to heat the source molecules, a thermocouple for temperature monitoring, and a shutter. Load lock chamber 101 is equipped with a turbo-molecular pump, a mechanical pump and pressure monitoring. The substrate 102 for the molecules to be deposited on is located in main chamber 103 approximately 20 cm distance from the evaporator unit containing the source molecules.
In one embodiment, in operation, single crystals of the λ-(BETS) 2 GaCl 4 compound are placed inside a Ta capsule and loaded into evaporator unit. Evaporator unit attached to load lock chamber 101 . The chamber 101 is then pumped down to approximately 2×10 −8 Torr pressure and held for approximately 12 hours to outgas the source. For further outgassing of source, the evaporator is heated to about 120° C. for 30 minutes prior to deposition of the source molecules.
A substrate is placed in the main chamber 103 and positioned about 20 cm from the source molecules. The λ-(BETS) 2 GaCl 4 compound is then deposited by heating of the source to about 160° C. for a deposition time of 20 seconds or less for superconductor wires, or between 30 seconds and 3 minutes for a single sheet of superconducting layer.
In another embodiment, a powder form of BETS molecules are placed inside a Ta capsule and loaded into evaporator unit. The outgassing of the source molecules is then accomplished as previously set forth above. Molecules are deposited by heating the source between 160° C. and 180° C., with the substrate being positioned about 20 cm from the source molecules.
Following deposition of the BETS molecules, GaCl 4 or HaCl 4 molecules are then deposited, followed by a second deposition of BETS molecules. The substrate is then heated to about 200° C. to obtain a uniform thin film.
The following example is included to demonstrate particular embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the example which follows represent techniques discovered by the inventors to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the scope of the invention.
Example 1
To prepare λ-(BETS) 2 GaCl 4 single crystals, BETS (3 mg) and Et4N—GaCl4 (50 mg) were dissolved in a mixture of chlorobenzene and ethanol (approximately 10.8 ml chlorobenzene, 1.2 ml ethanol). The electrochemical reaction was performed in H-shaped glass tube cells without glass frits. Platinum wires were used as electrodes. A constant current of 0.5 mA was applied for 2 to 3 weeks in different experimental runs. Crystals of very thin needles were obtained a few days after the current was turned on. The needles continued to grow in size, reaching an average length of 1.5 cm at the end of the reaction period. Typical dimensions of the single needle crystals obtained were 100 mm×100 mm×1.5 cm along crystallographic a, b and c axes, respectively. The X-ray diffraction pattern of the grown λ-(BETS) 2 GaCl 4 needles ( FIG. 16 ) shows a triclinic crystal structure with the following unit cell parameters: a=16.1544(14) Angstroms (Å), b=18.5976(16) Å, c=a 6.5946(6) Å, α=96.736(2), β=98.370(2), γ=112.562(2) and V=1777.13 Å. The BETS molecules were arranged along the [100] directions ( FIG. 17 ).
The custom evaporator unit for the molecule deposition included a Ta capsule, a resistive heating filament, a thermocouple for temperature monitoring and a shutter. For deposition of molecules, λ-(BETS) 2 GaCl 4 single crystals were placed in a Ta capsule. After loading the compound, the evaporator unit was attached to a load-lock chamber of the UHV system and then pumped to a pressure of 2×10 −8 torr for 12 hours to outgas. To further outgas the source, the evaporator was heated to 120° C. for 30 min. For the substrate, a Ag(111) single-crystal surface was cleaned by 11 cycles of sputtering with neon ions and annealing to 700 K. The sample temperature was then lowered to 80 K inside the STM chamber and the cleanliness of the sample checked by STM imaging.
After confirming an atomically clean sample surface, it was placed in the Ultra High Vacuum (UHV)-manipulator equipped with x, y, z and rotational stages, and heating/cooling facilities. During molecule deposition, the sample temperature was held at approximately 120 K. The λ-(BETS) 2 GaCl 4 compound was deposited by heating the source to 160° C. under UHV condition inside the deposition chamber of a custom-built UHV-LT-STM system.
The observation of superconductivity in just four pairs of (BETS) 2 GaCl 4 molecules opens up the possibility of investigating the superconducting phenomena locally. It might also lead to the fabrication of nanoscale superconducting devices based entirely on molecular materials, and to nanoscale electronic circuits that use superconducting nanowires as interconnects.
Although one or more aspects of the invention has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based upon a reading and understanding of this specification and the annexed drawings. The invention includes all such modifications and alterations and is limited only by the scope of the following claims. In addition, while a particular feature or aspect of the invention may have been disclosed with respect to only one of several implementations, such feature or aspect may be combined with one or more other features or aspects of the other implementations as may be desired and/or advantageous for any given or particular application. Further, the term “exemplary” as used herein merely meant to mean an example, rather than the best. Furthermore, to the extent that the terms “includes”, “having”, “has”, “with”, or variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.”
|
A method of forming a superconductive device of a single layer of (BETS) 2 GaCl 4 molecules on a substrate surface which displays a superconducting gap that increases exponentially with the length of the molecular chain is provided.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not applicable.
BACKGROUND OF THE INVENTION
The invention relates to a closure system for a leakproof baby feeding bottle.
In known baby feeding bottles, the teat at the lower edge has a peripheral teat flange which is secured sealingly to the edge of a bottle opening by means of a screw ring screwed onto an external thread of the bottle. In order to prevent leakage of liquid during breaks from drinking, a lid is placed between the teat flange and the flange edge and secured by means of the screw ring.
A more user-friendly leakproof baby feeding bottle is disclosed in DE 101 57 071 C1. Said bottle has a lower closure ring which is screwed onto the external thread of the bottle and which has a first seat surface with at least one first throughflow hole.
An upper closure ring has a second seat surface with at least one second throughflow hole. The two closure rings are able to be rotated relative to one another and releasably locked together via locking elements. By rotating the upper closure ring, the first and second throughflow holes are able to be brought into overlapping and non-overlapping positions. A drinking teat is screwed by means of a screw ring to an external thread of the upper closure ring. If the throughflow holes overlap one another, baby food is able to be taken through the drinking teat. If the throughflow holes do not overlap one another, the removal of baby food through the drinking teat is blocked.
In the exemplary embodiment, the closure rings comprise conical seat surfaces. Moreover, sealing rings are present on the lower face of the lower closure ring and on the upper face of the first seat surface. The lower closure ring comprises a locking projection protruding inwardly from the lower conical seat surface and the upper closure ring has snap tongues protruding from the lower second conical seat surface and which engage behind the locking projection.
The manufacture and usage of the leakproof bottle is, to a certain extent, still complicated. Due to the complex spatial shape, dirt is able to collect on the closure rings. The snap tongues come into contact with the baby food and have to be handled for dismantling. The cleaning of the closure rings is complicated.
WO 2007/042117 A1 discloses a leakproof baby feeding bottle which simplifies the manufacture and usage. One variant comprises a closure system with a lower closure ring, which has a substantially cylindrical first peripheral part with a first internal thread which is screwed onto an external thread of a bottle, and which comprises a first central part connected to the upper edge of the first peripheral part, with a first seat surface rotationally symmetrical about a longitudinal axis and facing away from the bottle interior, at least one first throughflow hole which opens, on the one hand, in the first seat surface and, on the other hand, in one side of the first central part facing the bottle interior and a soft elastic sealing material made of plastics material, injection-moulded onto the first seat surface at least around the edge of the throughflow hole and onto a sealing surface of the first central part sealingly positioned on the upper bottle edge and which extends from the first seat surface through the first throughflow hole along the side facing the bottle interior as far as the sealing surface of the first central part. Moreover, the closure system comprises an upper closure ring which has a substantially cylindrical second peripheral part with a second external thread, on which a drinking teat of a screw ring with an internal thread is fixed and which comprises a second central part connected to the second peripheral part, with a second seat surface rotationally symmetrical about the longitudinal axis and sealingly located on the first seat surface, and at least one second throughflow hole which opens, on the one hand, in the second seat surface and, on the other hand, in one side of the second central part remote therefrom, and which by rotating the upper closure ring relative to the lower closure ring may be brought into overlapping and non-overlapping positions relative to the first throughflow hole. Moreover, locking elements are present which rotatably and releasably connect together the lower closure ring and the upper closure ring relative to one another.
According to the exemplary embodiment, the soft elastic sealing material is injection-moulded on the lower closure ring and covers a circular portion surrounding the throughflow holes on the first seat surface. Moreover, on the inner periphery of the throughflow holes in each case the sealing material has a strip-shaped portion. On the lower face of the first central part, coming from the strip-shaped portions, further strip-shaped portions of the soft elastic sealing material are present, which extend down the inner face of a cylindrical portion of the first peripheral part and are connected at the bottom to an annular peripheral sealing surface made of the same material, which is arranged on the inner face of a step of the first peripheral part. The sealing material is, for example, a thermoplastic elastomer.
In the known closure system, the seal is created between the lower closure ring and the upper closure ring between the circular disc-shaped soft elastic sealing material of the first seat surface of the lower closure ring and the substantially planar second seat surface of the upper closure ring, located thereon. Here, it may lead to leakages, in particular when the seat surfaces do not bear exactly against one another with a specific contact pressure. Moreover, the friction between the first seat surface made of soft elastic sealing material and the second seat surface, may hinder the rotation of the upper closure ring relative to the lower closure ring.
Against this background, the object of the invention is to provide a closure system for a leakproof baby feeding bottle with improved usage properties.
BRIEF SUMMARY OF THE INVENTION
The closure system according to the invention for a leakproof baby feeding bottle comprises
a lower closure ring which has a substantially cylindrical lower peripheral part with an internal thread, which may be screwed onto an external thread of a bottle and comprises a lower partition connected to the lower peripheral part on the edge above the internal thread and blocking its cross section, with a first upper face and a first lower face, and at least one lower throughflow hole which opens, on the one hand, in the first upper face and, on the other hand, in the first lower face, an upper closure ring which comprises a substantially cylindrical upper peripheral part with an external thread for connecting to a screw ring for fastening a drinking teat to the upper peripheral part and an upper partition connected to the upper peripheral part on the edge and blocking its cross section, with a second upper face and a second lower face located sealingly on the first upper face and at least one upper throughflow hole which opens, on the one hand, in the second lower face and, on the other hand, in the second upper face, locking elements which rotatably and releasably lock together the lower closure ring and the upper closure ring relative to one another, a circular lip seal made of a soft elastic material concentric to the lower peripheral part being arranged on the first upper face, with at least one axially oriented sealing lip and at least one circular seal geometry engaging with the lip seal and concentric to the upper peripheral part being arranged on the second lower face or vice versa and by rotating the upper closure ring relative to the lower closure ring the upper throughflow hole may be brought into overlapping and non-overlapping positions relative to the lower throughflow hole.
The closure system according to the invention is able to be screwed by the internal thread of the lower closure ring to a leakproof baby feeding bottle. Moreover, a drinking teat is able to be screwed onto the external thread of the upper closure ring by means of a screw ring. In this case, the lower closure ring may be located sealingly on the upper edge of the bottle and the drinking teat may be located sealingly on the upper edge of the upper peripheral part of the upper closure ring.
The closure rings are connected together rotatably and releasably relative to one another via the locking elements. The closure rings have one lower and at least one upper throughflow hole which, by rotating the upper closure ring relative to the lower closure ring, may be brought into overlapping and non-overlapping positions. If the at least one lower and the at least one upper throughflow hole overlap, baby food is able to be taken. If they do not overlap, the closure system blocks the removal of liquid baby food. The lower closure ring and the upper closure ring bear with the first upper face and the second lower face flat against one another, so that in principle baby food is not able to flow out between the two closure rings to the side.
At least one circular lip seal and at least one circular seal geometry engaging therewith are present as an additional lateral seal of the contact region between the first upper face and the second lower face. In this case, either the lower closure ring has the at least one circular lip seal and the upper closure ring has the at least one circular seal geometry or the lower closure ring has the at least one circular seal geometry and the upper closure ring the at least one circular lip seal. It is also possible that both the upper closure ring and the lower closure ring have at least one circular lip seal and at least one circular seal geometry. The at least one circular lip seal and the at least one circular seal geometry are arranged such that they surround the lower and the upper throughflow holes. They are arranged concentrically to the lower peripheral part and the upper peripheral part, so that they do not hinder the rotation of the upper closure ring relative to the lower closure ring. By the at least one circular lip seal and the at least one circular seal geometry, the seal between the lower and upper closure rings is improved and the escape of liquid baby food to the side is prevented even more effectively. In this case, it is particularly advantageous that the axially oriented sealing lip and a corresponding seal geometry in the axial direction of the cylindrical peripheral parts engage in one another so that the lower closure ring and the upper closure ring may be easily joined together and separated from one another.
The closure system according to the invention for a leakproof baby feeding bottle comprises
a lower closure ring which has a substantially cylindrical lower peripheral part with an internal thread, which may be screwed onto an external thread of a bottle and comprises a lower partition connected to the lower peripheral part on the edge above the internal thread and blocking its cross section, with a first upper face and a first lower face and at least one lower throughflow hole which opens, on the one hand, in the first upper face and, on the other hand, in the first lower face, an upper closure ring which comprises a substantially cylindrical upper peripheral part with an external thread for connecting to a screw ring for fastening a drinking teat to the upper peripheral part and an upper partition connected to the upper peripheral part on the edge and blocking its cross section, with a second upper face and a second lower face located sealingly on the first upper face and at least one upper throughflow hole which opens, on the one hand, in the second lower face and, on the other hand, in the second upper face, locking elements which rotatably and releasably lock together the lower closure ring and the upper closure ring relative to one another, at least one cake slice-shaped sealing cushion made of a soft elastic material being arranged on the first upper face of the lower partition and at least one upper throughflow hole with a sealing seat on the edge complementary to the cake-slice shape being arranged in the second lower face of the upper partition or vice versa and optionally the upper throughflow hole being able to be brought by rotating the upper closure ring relative to the lower closure ring into an overlapping position relative to the lower throughflow hole and the sealing seat into the sealed position relative to the sealing cushion.
The closure system according to the invention is able to be screwed by the internal thread of the lower closure ring onto a leakproof baby feeding bottle. Moreover, a drinking teat is able to be screwed by means of a screw ring onto the external thread of the upper closure ring. In this case, the lower closure ring is able to be located sealingly on the upper edge of the bottle and the drinking teat is able to be located sealingly on the upper edge of the upper peripheral part of the upper closure ring.
The closure rings are connected together rotatably and releasably relative to one another via the locking elements. The closure rings have one lower and at least one upper throughflow hole which, by rotating the upper closure ring relative to the lower closure ring, may be brought into overlapping and non-overlapping positions. If the at least one lower and the at least one upper throughflow hole overlap, baby food is able to be removed. If they do not overlap, the closure system blocks the removal of liquid baby food. The lower closure ring and the upper closure ring bear with the first upper face and the second lower face flat against one another so that, in principle, baby food is not able to flow out to the side between the two closure rings.
If the upper closure ring is rotated relative to the lower closure ring such that it is arranged with the one sealing seat in a sealed position relative to the at least one sealing cushion, the throughflow of liquid baby food is prevented through the at least one lower throughflow hole and the at least one upper throughflow hole. At the same time, therefore, it is prevented that liquid baby food escapes to the side through the contact region between the first upper face of the lower partition and the second lower face of the upper partition. The at least one sealing cushion is arranged either on the first upper face of the lower partition and the at least one sealing seat is arranged on the second lower face of the upper partition or the at least one sealing cushion is arranged on the second lower face of the upper partition and the at least one sealing seat is arranged on the first upper face of the lower partition. Moreover, the invention incorporates possible embodiments in which the lower partition comprises at least one cake slice-shaped sealing cushion and at least one cake slice-shaped sealing seat and the upper partition at least one sealing cushion complementary thereto and at least one sealing seat complementary to the at least one cake slice-shaped sealing cushion of the lower partition.
The cake-slice shape of the sealing cushion and the sealing seat complementary thereto promote a particularly advantageous shape of the throughflow holes for the removal of liquid baby food and a particularly sealed seal of said throughflow holes. According to a preferred embodiment, the sealing seat is a peripheral edge about the at least one upper throughflow hole, against which the sealing cushion sealingly bears on the edge, when the sealing seat is brought into the sealed position relative to the sealing cushion. The edge is able to be produced with a particularly dimensionally stable or respectively smooth surface. Preferably, it is a chamfer or respectively bevel on the edge of the throughflow hole, into which the sealing cushion is pressed, said sealing cushion bearing sealingly with its edge against the chamfer or bevel.
According to an embodiment of the invention, the outflow of liquid food to the side between the upper and lower closure part is also reliably prevented, when the lower and upper throughflow holes overlap one another.
According to a preferred embodiment which further improves the seal on the edge, the lip seal is a double lip seal.
According to a further embodiment which improves the removal of liquid food and the seal of the closure rings, the lower closure ring and the upper closure ring in each case comprise two diametrically opposing throughflow holes and/or the lower closure ring comprises two diametrically opposing cake slice-shaped sealing cushions and the upper closure ring comprises two diametrically opposing throughflow holes with a sealing seat on the edge or vice versa.
The locking elements may be designed in different ways. According to a preferred embodiment, they are parts of a bayonet closure. A bayonet closure permits a simple connection of the closure ring and the upper closure ring with one another and also allows the user the easy separation of the lower and upper closure ring.
According to a further embodiment, the lower closure ring above the internal thread comprises a circular peripheral sealing element made of a soft elastic material for sealing to the upper edge of a bottle. As a result, the sealing seat of the closure system on the bottle is assisted. In principle, however, it is also possible to insert a specific sealing ring between the closure system and the bottle.
According to a preferred embodiment, the sealing element is circular disc-shaped.
According to a further embodiment, the lip seal and the sealing element consist of a soft elastic material which extends from the lip seal over the first upper face of the lower partition and through the lower through-holes as far as the sealing element. The sealing elements may then be injection-moulded continuously on the lower closure ring. This is advantageous in terms of production technology.
According to one embodiment, the lower and/or upper closure ring comprising the lip seal and/or the sealing cushion and/or the sealing element is produced in a two-component injection-moulding process from a soft elastic plastics component for the lip seal and/or the sealing cushion and/or the sealing element and also from a hard elastic plastics component. The two-component-injection moulding process may be, in particular, a core retraction process or a transfer process.
According to a further embodiment, the lip seal and/or the sealing cushion and/or the sealing element consist of thermoplastic elastomer. The production from thermoplastic elastomer promotes, in particular, the material connection between the lip seal and/or sealing cushion and/or sealing element with the remaining parts of the lower and/or upper closure ring. Basically, it is also possible to connect the lip seal and/or the sealing cushion and/or the sealing element positively and/or non-positively to the remaining parts of the lower and/or closure ring. This applies both to the embodiments of these seals made of thermoplastic elastomer and to possible embodiments of these seals made of a different sealing material, such as for example rubber or silicone.
According to a preferred embodiment, the first upper face is planar and the second lower face is planar. It is further preferred if the first lower face and the second upper face are planar.
According to a further embodiment, the lower closure ring is screwed onto a baby feeding bottle.
According to a further embodiment a drinking teat is held by means of a screw ring on the upper closure ring.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention is described in more detail hereinafter with reference to the accompanying drawings of an exemplary embodiment. In the drawings:
FIG. 1 shows a closure system screwed onto a baby feeding bottle with a screwed-on drinking teat in a vertical section;
FIGS. 2 a to e show the same closure system in side view ( FIG. 2 a ), in a view from the left-hand side ( FIG. 2 b ), in a view from the right-hand side ( FIG. 2 c ), in a view from below ( FIG. 2 d ) and in plan view ( FIG. 2 e );
FIGS. 3 a to g show the lower closure ring of the same closure system in front view ( FIG. 3 a ), in a view from the right-hand side ( FIG. 3 b ), in plan view ( FIG. 3 c ), in a view from below ( FIG. 3 d ), in a section along the line A-A of FIG. 3 b ( FIG. 3 e ), in a section along the line B-B of FIG. 3 a ( FIG. 3 f ) and in a perspective view obliquely from above and from the side ( FIG. 3 g );
FIGS. 4 a to f show the upper closure ring of the same closure system in front view ( FIG. 4 a ), in a view from the right-hand side ( FIG. 4 b ), in plan view ( FIG. 4 c ), in a view from below ( FIG. 4 d ), in a section along the line B-B of FIG. 4 a ( FIG. 4 e ), in a section along the line C-C of FIG. 4 a ( FIG. 4 f ) and in a perspective view obliquely from above and from the side ( FIG. 4 g ).
DETAILED DESCRIPTION OF THE INVENTION
While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated.
In the present application, the terms “top” and “bottom” refer to the alignment of the closure system if said closure system is screwed onto a bottle and is screwed to a drinking teat, the bottle being vertically aligned and being positioned with the base on a surface and the drinking teat being arranged above the bottle.
According to FIG. 1 a closure system 20 comprising a lower closure ring 30 and an upper closure ring 60 is screwed onto a baby feeding bottle 10 , and a drinking teat 100 is screwed onto the closure system 20 by means of a screw ring 90 .
The bottle 10 has a cylindrical, waisted bottle body 11 which comprises a base 12 at the lower end and a neck 13 at the upper end. The neck 13 is designed as a wide neck but has a smaller diameter than the region of the bottle body 11 located therebelow. The neck 13 has a single-flight external bottle thread 14 and at the top has a bottle opening 15 . The bottle opening 15 is surrounded by an upper bottle edge 16 . The bottle 10 has a longitudinal centre axis 17 .
As visible in particular from FIGS. 2 and 3 , the lower closure ring 30 has a substantially cylindrical lower peripheral part 31 which comprises a plurality of portions. The first lower peripheral part portion 32 of substantially cylindrical shape has an internal thread 33 on the internal periphery, which according to FIG. 1 is screwed onto the external bottle thread 14 . A second lower peripheral part portion 34 protrudes radially outwards and downwards from the periphery of the first lower peripheral part portion 32 , and which covers the bottle neck 13 to the side.
Moreover, the lower peripheral part 31 has a third lower peripheral part portion 35 protruding radially inwards from the upper edge of the first lower peripheral part portion 22 , which is substantially circular disc-shaped. A substantially cylindrical fourth lower peripheral part portion 36 protrudes axially upwards from the inside of the third lower peripheral part portion 35 .
A lower partition 37 is connected to the upper edge of the fourth upper peripheral part portion 36 , and which substantially blocks the cross section of the lower closure ring 30 .
Said circular disc-shaped partition 37 has a substantially planar first upper face 38 and a substantially planar first lower face 39 . Moreover, it comprises diametrically opposing lower cake slice-shaped throughflow holes 40 , 41 which extend from the first upper face 38 as far as the first lower face 39 .
The first upper face 38 is surrounded by a circular double lip seal 42 , the sealing lips 43 , 44 thereof extending upwards perpendicular to the first upper face 38 . The double lip seal may also be denoted as a “double-lamella seal”. Moreover, two diametrically opposing cake slice-shaped sealing cushions 45 , 46 are arranged on the first upper face 38 , said diametrically opposing cake slice-shaped sealing cushions being arranged on the angle bisector between the two lower cake slice-shaped lower throughflow holes 40 , 41 .
The cake slice-shaped throughflow holes 40 , 41 and the cake slice-shaped sealing cushions 45 , 46 widen at an increasing distance from the centre of the circular disc-shaped partition 37 .
Moreover, the closure ring on the lower face of the second lower peripheral part portion has a circular disc-shaped sealing element 47 .
Moreover, the lower closure ring 30 on the outer periphery of the first lower peripheral part portion 32 has two opposing longitudinal grooves 48 , 49 which in each case are connected to an annular groove 50 , 51 , which at the bottom is defined by the second lower peripheral part portion 34 . Adjacent to each longitudinal groove 48 , 49 in the respective adjacent annular groove 50 , 51 a latching projection 52 , 53 is present in each case. The latching projections 52 , 53 have in each case a chamfer toward the longitudinal sides 48 , 49 and/or the annular grooves 50 , 51 . The annular grooves 50 , 51 are in each case defined on the opposing ends by stops 54 , 55 , which at the same time separate the annular grooves 50 , 51 from the adjacent longitudinal grooves 48 , 49 .
On the second lower peripheral part portion externally on diametrically opposing peripheral regions, in each case are two semi-circular lower raised portions 56 , 57 with the printed text “press open”. By pressing against the semi-circular lower raised portion 56 , 57 , it is possible to displace the latching projections 52 , 53 , arranged adjacent thereto, slightly inwards.
The lower closure ring 30 is, in principle, produced from a hard elastic plastics material, for example from polypropylene (PP). A soft elastic sealing material is injection-moulded on the lower closure ring 30 which forms the double lip seal 42 , the sealing cushions 45 , 46 and the sealing element 47 . The sealing material is injection-moulded such that it connects all the aforementioned seals 42 , 45 , 46 , 47 together. For example, it is a thermoplastic elastomer (TPE).
According to FIGS. 2 and 4 , the upper closure ring 60 has an upper peripheral part 61 with a plurality of portions. The substantially cylindrical first upper peripheral part portion 62 has an external thread 63 on the external periphery. The first upper peripheral part portion 62 is connected on the lower edge to a second upper peripheral part portion 64 protruding radially outwards. The second upper peripheral part portion 64 is connected in turn on the external periphery to a third upper peripheral part portion 65 protruding axially downwards. The third upper peripheral part portion 65 has on the inner periphery two protruding claws 66 , 67 which diametrically oppose one another. On the outside, the third upper peripheral part portion 65 has two semi-circular upper raised portions 68 , 69 protruding radially outwards, which also diametrically oppose one another. The upper raised portions 68 , 69 are offset by 90° relative to the claws 66 , 67 .
Moreover, the upper closure ring 60 comprises a circular disc-shaped upper partition 70 which, slightly below the upper edge of the first upper peripheral part portion 62 , is connected thereto and blocks the cross section of the upper peripheral part 61 . The upper partition 70 has a substantially planar second upper face 71 and a substantially planar second lower face 72 . Moreover, it has diametrically opposing cake slice-shaped upper through-holes 73 , 74 , which in each case open into the second upper face 71 and into the second lower face 72 . The upper through holes 73 , 74 diametrically oppose one another.
On the second lower face 72 , the upper partition 70 has a circular seal geometry 75 complementary to the double lip seal. This seal geometry 75 has two circular peripheral sealing grooves 76 , 77 , into which the sealing lips 43 , 44 of the double lip seal 42 are able to engage. The seal geometry 75 is arranged concentrically to the first upper peripheral part 61 and to the circular disc-shaped upper partition 70 .
The upper closure ring is, for example, produced from PP.
The upper closure ring 60 is able to be inserted with the claws 66 , 67 into the longitudinal grooves 48 , 49 of the lower closure ring 30 , until the claws 66 , 67 strike against the second lower peripheral part portion 34 . In this case, the double lip seal 42 engages in the sealing grooves 76 , 77 of the seal geometry 75 . By rotating the upper closure ring 60 by approximately 15° the claws 66 , 67 of the upper closure ring 60 spring over the latching projections 52 , 53 of the lower closure ring 30 so that the lower and the upper closure ring 30 , 60 are captively connected together. If the claws 66 , 67 have sprung over the latching projections 52 , 53 , the lower and upper through-holes 40 , 41 and 73 , 74 are in an overlapping position in which liquid is able to pass through the closure system 20 . This position is shown in FIG. 1 .
By further rotation of the upper closure ring 60 relative to the lower closure ring 30 until the claws 66 , 67 strike against the stops 55 , 56 , the upper throughflow holes 73 , 74 are sealed by the sealing cushions 45 , 46 of the lower closure ring 30 . In this case, the sealing cushions 45 , 46 bear sealingly on the edge against chamfers or respectively bevels on the edge of the throughflow holes 73 , 74 , which form sealing seats. The closure system 20 is then closed and liquid is not able to pass through the through-holes 40 , 41 , 73 , 74 . At the moment of closure, the closure system 20 emits an acoustic clicking noise.
The closure system 20 is opened again by the upper closure ring 60 being rotated in the opposing direction until it reaches the position in which the claws strike against the latching projections 55 , 56 . This stop position can only be overcome when the lower closure ring is deformed by compressing the two semi-circular lower raised portions 56 , 57 . The lower closure ring 30 may only be deformed when the closure system 20 has been screwed off the bottle 10 . The upper raised portions 68 , 69 on the upper closure ring 60 simplify the rotation of the upper closure ring 60 relative to the lower closure ring 30 . Moreover, with a suitable arrangement of specific positions, they may display, for example, the position in which the claws 66 , 67 engage in the longitudinal grooves 48 , 49 .
According to FIG. 1 , the screw ring 90 has a circular cylindrical annular portion 91 with an internal screw ring thread 92 on the inner periphery and an annular flange 93 protruding radially inwards from the upper edge, with a screw ring-annular groove 94 on the lower face. The screw ring 90 is screwed to the external thread 63 . The annular flange 93 is pressed against the upper edge of the second closure ring.
The screw ring may comprise on the outer periphery a coating 95 made of a soft elastic plastics material. It is, for example, injection-moulded from PP and the soft elastic material is, for example, injection-moulded TPE.
According to FIG. 1 the drinking teat 100 has a mouthpiece 101 with a slotted valve 102 and a teat 103 with a drinking hole 104 and/or drinking slot at the end and a spout 105 carrying the mouthpiece 101 . On the lower edge of the spout 105 it has an outwardly oriented teat flange 106 with an upwardly protruding sealing bead 107 . The drinking teat 100 is, for example, produced from rubber and/or latex or silicone rubber.
According to FIG. 1 , the drinking teat 100 is clamped on the teat flange 106 between the upper edge of the upper closure ring 60 and screw ring 90 . The sealing bead 107 is fixed in the screw ring-annular groove 94 to the lower face of the annular flange 93 .
The screw ring 90 in the closed or open state of the closure system 20 may be screwed onto the closure system or respectively screwed off said closure system.
The novel closure system 20 may be moved by means of rotational movement from the closed state into the open state and vice versa. No individual parts have to be removed in order to bring the closure system 20 into the operative state. Also there is no direct contact with the user and with the food when opening and closing the closure system 20 . The risk of contamination of the food is thus considerably reduced. Moreover, it is not possible to lose any individual parts. The closure system 20 can be used for bottles 10 and other containers.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
|
A closure system for a baby bottle including a lower closure ring screwed onto an external thread of a bottle, an upper closure ring for connecting to a screw ring for fastening a drinking teat, locking elements which rotatably and releasably lock together the lower closure ring and the upper closure ring, a circular lip seal made of a soft elastic material concentric to a lower peripheral part being arranged on the first upper face, with at least one axially oriented sealing lip and at least one circular seal geometry engaging with the lip seal and concentric to an upper peripheral part being arranged on a second lower face or vice versa and by rotating the upper closure ring relative to the lower closure ring the upper throughflow hole may optionally be brought into overlapping and non-overlapping positions relative to a lower throughflow hole.
| 0
|
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a circular pole piece included in a magnetic circuit for magnetic resonance imaging (MRI) and an MRI system. More particularly, the present invention relates to a circular pole piece capable of minimizing a residual magnetic induction and an MRI system employing the circular pole piece.
[0002] In the past, a circular pole piece included in a magnetic circuit for magnetic resonance imaging (MRI) has been shaped substantially circularly as a whole by arranging laminate blocks each of which has square or rectangular silicon steel sheet tiles or heteromorphic soft magnetic material tiles, each of which is used to fill a gap among adjoining square or rectangular tiles, layered (see, for example, FIG. 1 in Patent Document 1). Otherwise, the circular pole piece has been shaped substantially circularly as a whole by arranging laminate blocks, each of which has trapezoidal or annularly sectoral soft magnetic material tiles, layered in the form of multiple concentric rings (see, for example, FIG. 21 in the Patent Document 1).
[0003] The soft magnetic material tiles are made of, for example, a silicon steel sheet and exhibit a hysteresis. Therefore, after a magnetic field gradient is applied to the circular pole piece, a residual magnetic induction occurs in the circular pole piece. The magnetic induction varies depending on a change in the magnetic field gradient. However, when the residual magnetic induction in the circular pole piece varies, it affects an image.
[0004] In the past, efforts have been made to devise a pulse sequence that is effective in suppressing the adverse effect (refer to, for example, Patent Document 2).
[0005] [Patent Document 1]
[0006] Japanese Unexamined Patent Application Publication No. 2000-200716
[0007] [Patent Document 2]
[0008] Japanese Unexamined Patent Application Publication No. 2000-185023
[0009] In the past, the adverse effect of the residual magnetic induction in a circular pole piece has been suppressed by devising a pulse sequence. However, this imposes a load on an MRI system.
BRIEF DESCRIPTION OF THE INVENTION
[0010] An object of the present invention is to provide a circular pole piece and an MRI system capable of minimizing a residual magnetic induction.
[0011] According to the first aspect of the present invention, a circular pole piece included in a magnetic circuit for magnetic resonance imaging is divided into at least two portions, that is, a center portion including the center of the circular pole piece and a marginal portion including the margin thereof. The permeability which the center portion made of a soft magnetic material exhibits with an external magnetic field applied thereto is higher than that of the marginal portion made of a soft magnetic material.
[0012] The higher the permeability is, the smaller the residual magnetic induction in a soft magnetic material is. Therefore, the permeability should be as high as possible.
[0013] On the other hand, the external magnetic field strength applied to the center portion of the circular pole piece is different from that applied to the marginal portion thereof. The external magnetic field strength applied to the center portion ranges, for example, from 20 A/m to 60 A/m, while the external magnetic field strength applied to the marginal portion ranges, for example, from 50 A/m to 150 A/m.
[0014] The permeability of a soft magnetic material varies depending on the strength of an applied magnetic field. The strength of an external magnetic field maximizing the permeability depends on the soft magnetic material.
[0015] In the circular pole piece in accordance with the first aspect, the permeability which the center portion made of a soft magnetic material exhibits with a feebler external magnetic field than that applied to the marginal portion applied thereto is higher than the permeability which the marginal portion made of a soft magnetic material exhibits with a stronger external magnetic field than that applied to the center portion applied thereto. This results in a smaller residual magnetic induction in the center portion located near an imaging area. Although the residual magnetic induction in the marginal portion is larger than that in the center portion, the adverse effect of the residual magnetic induction in the marginal portion is limited because the marginal portion is located far from the imaging area.
[0016] According to the second aspect of the present invention, a circular pole piece has the same structure as the foregoing one. However, the compositions of the soft magnetic materials to be made into the respective portions of the circular pole piece are different from each other.
[0017] In the circular pole piece in accordance with the second aspect, the soft magnetic material to be made into the center portion and that to be made into the marginal portion are selected under the following conditions.
[0018] (1) Adopted as the soft magnetic material to be made into the center portion is a soft magnetic material that exhibits as high a permeability as possible (for example, 10000 or more) with a relatively small external magnetic field (for example, ranging from 20 A/m to 60 A/m) applied thereto.
[0019] (2) Adopted as the soft magnetic material to be made into the marginal portion is a soft magnetic material that exhibits as high a permeability as possible (for example, 6000 or more) with a relatively large external magnetic field (for example, ranging from 50 A/m to 150 A/m) applied thereto.
[0020] (3) The permeability which the soft magnetic material to be made into the center portion exhibits with an external magnetic field applied thereto is higher than the one which the soft magnetic material to be made into the marginal portion exhibits with an external magnetic field applied thereto. Experiments performed by the present inventor demonstrate that: when the maximum value of the permeability which the soft magnetic material to be made into the center portion exhibits with an external magnetic field applied thereto is twice or more higher than that of the permeability of the soft magnetic material to be made into the marginal portion, the residual magnetic induction in the center portion located near the imaging area can be minimized.
[0021] According to the third aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. Herein, the center portion made of a soft magnetic material has a plurality of directional magnetic steel sheet tiles layered with the directions of the axes of easy magnetization of the respective tiles varied so that the tiles will exhibit a non-directional property as a whole. The marginal portion made of a soft magnetic material is formed with non-directional magnetic steel sheet tiles devoid of an axis of easy magnetization.
[0022] The permeability of a directional magnetic steel sheet is higher in the center thereof to which a relatively week external magnetic field is applied. On the other hand, the permeability of a non-directional magnetic steel sheet is lower than the permeability which the center of the directional magnetic steel sheet exhibits with an external magnetic field applied thereto. However, the non-directional magnetic steel sheet is inexpensive.
[0023] Therefore, in the circular pole piece in accordance with the third aspect, the directional magnetic steel sheet is adopted for the center portion, and the non-directional magnetic steel sheet is adopted for the marginal portion. Consequently, the residual magnetic induction in the center portion located near the imaging area can be minimized, and the cost of the circular pole piece can be lowered.
[0024] Moreover, directional magnetic steel sheet tiles are layered with the directions of the axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole. Therefore, a residual magnetic induction can be minimized irrespective of the direction of an external magnetic field (in particular, the direction of a magnetic field gradient).
[0025] According to the fourth aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. Herein, the center portion made of a soft magnetic material has a plurality of directional magnetic steel sheet tiles layered with the directions of the axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole, and has a non-directional magnetic steel sheet tile, which is devoid of an axis of easy magnetization, layered in combination with the directional magnetic steel sheet tile. The marginal portion made of a soft magnetic material is formed with non-directional magnetic steel sheet tiles devoid of an axis of easy magnetization.
[0026] The permeability of a directional magnetic steel sheet is higher in the center thereof to which a relatively feeble external magnetic field is applied. On the other hand, the permeability of a non-directional magnetic steel sheet is lower than the permeability which the center of the directional magnetic steel sheet exhibits with an external magnetic field applied thereto. However, the non-directional magnetic steel sheet is inexpensive.
[0027] In the circular pole piece in accordance with the fourth aspect, the center portion is formed by combining a directional magnetic steel sheet and a non-directional magnetic steel sheet, and the marginal portion is formed with a non-directional magnetic steel sheet. Consequently, the residual magnetic induction in the center portion located near the imaging area can be minimized, and the cost of the circular pole piece can be further lowered.
[0028] Moreover, directional magnetic steel sheet tiles are layered with the directions of the axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole. A residual magnetic induction can therefore be minimized irrespective of the direction of an external magnetic field (especially, the direction of a magnetic field gradient).
[0029] According to the fifth aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. Herein, the center portion of the circular pole piece made of a soft magnetic material has a plurality of directional magnetic steel sheet tiles layered with the directions of the axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole. The marginal portion made of a soft magnetic material has a plurality of directional magnetic steel sheet tiles layered with the directions of the axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole, and has a non-directional magnetic steel sheet tile, which is devoid of an axis of easy magnetization, layered in combination with the directional magnetic steel sheet tiles.
[0030] The permeability of a directional magnetic steel sheet is higher in the center of the directional magnetic steel sheet to which a relatively feeble external magnetic field is applied. On the other hand, the permeability of a non-directional magnetic steel sheet is lower than the permeability which the center of the directional magnetic steel sheet exhibits with the external magnetic field applied thereto. However, the non-directional magnetic steel sheet is inexpensive.
[0031] In the circular pole piece in accordance with the fifth aspect, a directional magnetic steel sheet is adopted for the center portion, and the combination of a directional magnetic steel sheet and a non-directional magnetic steel sheet is adopted for the marginal portion. Consequently, the residual magnetic induction in the center portion located near the imaging area can be minimized, and the cost of the circular pole piece can be lowered.
[0032] Moreover, directional magnetic steel sheet tiles are layered with the directions of the axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole. A residual magnetic induction can therefore be minimized irrespective of the direction of an external magnetic field (especially, the direction of a magnetic field gradient).
[0033] According to the sixth aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. Herein, the center portion made of a soft magnetic material and the marginal portion made of a soft magnetic material have a plurality of directional magnetic steel sheet tiles layered with the directions of the axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole.
[0034] The permeability of a directional magnetic steel sheet is relatively high in the center of the directional magnetic steel sheet to which a relatively feeble external magnetic field is applied. The permeability thereof in the margin thereof to which a relatively strong external magnetic field is applied is relatively low.
[0035] In the circular pole piece in accordance with the sixth aspect, the same directional magnetic steel sheet is adopted for the center portion and marginal portion. Consequently, the residual magnetic induction in the center portion located near the imaging area can be minimized, and the labor for using different soft magnetic materials is obviated.
[0036] Moreover, directional magnetic steel sheet tiles are layered with the directions of the axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole. A residual magnetic induction can be minimized irrespective of the direction of an external magnetic field (especially, the direction of a magnetic field gradient).
[0037] According to the seventh aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. Herein, the center portion made of a soft magnetic material and the marginal portion made of a soft magnetic material have a plurality of directional magnetic steel sheet tiles layered with the directions of the axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole, and has a non-directional magnetic steel sheet tile, which is devoid of an axis of easy magnetization, layered in combination with the directional magnetic steel sheet tiles.
[0038] The permeability of a directional magnetic steel sheet is relatively high in the center of the directional magnetic steel sheet to which a relatively feeble external magnetic field is applied. The permeability of the directional magnetic steel sheet is relatively low in the margin thereof to which a relatively strong external magnetic field is applied. On the other hand, the permeability of a non-directional magnetic steel sheet is lower than the permeability which the center of the directional magnetic steel sheet exhibits with an external magnetic field applied thereto. However, the non-directional magnetic steel sheet is inexpensive.
[0039] In the circular pole piece in accordance with the seventh aspect, the combination of a directional magnetic steel sheet and a non-directional magnetic steel sheet is adopted for both the center portion and marginal portion. Consequently, the residual magnetic induction in the center portion located near the imaging area can be minimized, and the cost of the circular pole piece can be lowered.
[0040] Moreover, directional magnetic steel sheet tiles are layered with the directions of axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole. Consequently, the residual magnetic induction can be minimized irrespective of the direction of an external magnetic field (especially, the direction of a magnetic field gradient).
[0041] According to the eighth aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. Herein, the ratio of a non-directional magnetic steel sheet tile to directional magnetic steel sheet tiles is higher in the marginal portion made of a soft magnetic material than in the center portion made of a soft magnetic material.
[0042] The higher the ratio of a non-directional magnetic steel sheet tile to directional magnetic steel sheet tiles is, the lower the permeability is.
[0043] In the circular pole piece in accordance with the eighth aspect, the ratio of a non-directional magnetic steel sheet tile adopted for the center portion is relatively low, and the ratio of a non-directional steel sheet adopted for the marginal portion is relatively high. Consequently, the residual magnetic induction in the center portion located near the imaging area can be minimized, and the cost of the circular pole piece can be lowered.
[0044] According to the ninth aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. Herein, the center portion made of a soft magnetic material has a plurality of directional magnetic steel sheet tiles layered with the directions of axes of easy magnetization thereof varied so that the tiles will exhibit a non-directional property as a whole. The marginal portion made of a soft magnetic material is formed with ferrite tiles.
[0045] In the circular pole piece in accordance with the ninth aspect, the permeability which the center portion made of a soft magnetic material exhibits with an external magnetic field applied thereto is higher than the permeability of the marginal portion made of a soft magnetic material. Consequently, the residual magnetic induction in the center portion can be minimized.
[0046] According to the tenth aspect of the present invention, a circular pole has the same structure as the aforesaid ones. Herein, the center portion made of a soft magnetic material is formed by combining a plurality of directional magnetic steel sheets tiles that is manufactured with the directions of axes of easy magnetization thereof varied and is layered so that the tiles will exhibit a non-directional property as a whole, and non-directional magnetic steel sheet tiles devoid of an axis of easy magnetization. The marginal portion made of a soft magnetic material is formed with ferrite tiles.
[0047] In the circular pole piece in accordance with the tenth aspect, the permeability which the center portion made of a soft magnetic material exhibits with an external magnetic field applied thereto is higher than the permeability of the marginal portion made of a soft magnetic material. Consequently, the residual magnetic induction in the center portion can be minimized.
[0048] According to the eleventh aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. Herein, the center portion made of a soft magnetic material is formed with amorphous soft magnetic material tiles, and the marginal portion made of a soft magnetic material is formed with non-directional magnetic steel sheet tiles devoid of an axis of easy magnetization.
[0049] The permeability of an amorphous soft magnetic material is higher than the permeability of a non-directional magnetic steel sheet.
[0050] In the circular pole piece in accordance with the eleventh aspect, the amorphous soft magnetic material is adopted for the center portion. Consequently, the residual magnetic induction in the center portion can be minimized.
[0051] According to the twelfth aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. The center portion made of a soft magnetic material is formed with Permalloy tiles, and the marginal portion made of a soft magnetic material is formed with non-directional magnetic steel sheet tiles devoid of an axis of easy magnetization.
[0052] The permeability of Permalloy is higher than that of the non-directional magnetic steel sheet.
[0053] In the circular pole piece in accordance with the twelfth aspect, Permalloy is adopted for the center portion. Consequently, the residual magnetic induction in the center portion can be minimized.
[0054] According to the thirteenth aspect of the present invention, a circular pole piece has the same structure as the aforesaid ones. Herein, the center portion made of a soft magnetic material is formed with Permalloy tiles, and the marginal portion made of a soft magnetic material is formed with ferrite tiles.
[0055] The permeability of Permalloy is higher than that of a ferrite.
[0056] In the circular pole piece in accordance with the thirteenth aspect, Permalloy is adopted for the center portion. Consequently, the residual magnetic induction in the center portion can be minimized.
[0057] According to the fourteenth aspect of the present invention, there is provided an MRI system including a circular pole piece that has the same structure as the aforesaid ones.
[0058] In the MRI system in accordance with the fourteenth aspect, the residual magnetic induction in the center portion of the circular pole piece can be minimized. Consequently, the adverse effect of the residual magnetic induction can be suppressed, and the MRI image quality can be improved.
[0059] According to a circular pole piece and an MRI system in which the present invention is implemented, the residual magnetic induction in the center portion of the circular pole piece located near an imaging area can be minimized. This results in the improved MRI image quality.
[0060] Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0061] [0061]FIG. 1 is a plan view showing a circular pole piece in accordance with a first embodiment of the present invention.
[0062] [0062]FIG. 2 is an A-A′ sectional view of the circular pole piece shown in FIG. 2.
[0063] [0063]FIG. 3 is a perspective view showing the laminate structure of a center-portion laminate block employed in the first embodiment.
[0064] [0064]FIG. 4 is a perspective view showing the laminate structure of a marginal-portion laminate block employed in the first embodiment.
[0065] [0065]FIG. 5 shows a characteristic curve indicating the changes in the permeabilities of a directional magnetic steel sheet and a non-directional magnetic steel sheet respectively deriving from application of an external magnetic field.
[0066] [0066]FIG. 6 is an explanatory diagram concerning a method of manufacturing directional magnetic steel sheet tiles employed in the first embodiment.
[0067] [0067]FIG. 7 is an explanatory diagram showing integration of a center-portion laminate block through bonding employed in the first embodiment.
[0068] [0068]FIG. 8 is an explanatory diagram concerning a method of manufacturing non-directional magnetic steel sheet tiles employed in the first embodiment.
[0069] [0069]FIG. 9 is a perspective view showing the laminate structure of a laminate block employed in second to fourth embodiments.
[0070] [0070]FIG. 10 is a sectional view showing the major part of an MRI system in accordance with an eighth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0071] The present invention will be described in relation to illustrated embodiments below.
First Embodiment
[0072] [0072]FIG. 1 is a plan view showing a circular pole piece 300 in accordance with a first embodiment. FIG. 2 is an A-A′ sectional view of the circular pole piece shown in FIG. 1.
[0073] The circular pole piece 300 comprises: a ring 101 ; a disk-like base 102 disposed inside the ring 101 and made of a carbon steel; center-portion laminate blocks 303 a arranged substantially circularly on the center portion of the base 102 ; and marginal-portion laminate blocks 303 b arranged substantially like a doughnut on the marginal portion of the base 102 .
[0074] The height of the center-portion laminate blocks 303 a is, for example, 42 mm, and the height of the marginal-portion laminate blocks 303 b is, for example, 36 mm.
[0075] [0075]FIG. 3 is an explanatory diagram showing the laminate structure of each of the center-portion laminate blocks 303 a.
[0076] Each of the center-portion laminate blocks 303 a comprises: a directional magnetic steel sheet tile 90 having an axis of easy magnetization Ax in the direction of the short sides of the block; a directional magnetic steel sheet tile 91 having an axis of easy magnetization Ax in a direction defined by turning the short-side direction 30 □ clockwise; a directional magnetic steel sheet tile 92 having an axis of easy magnetization Ax in a direction defined by turning the short-side direction 60 □ clockwise; a directional magnetic steel sheet tile 93 having an axis of easy magnetization Ax in the direction of the long sides of the block; a directional magnetic steel sheet tile 92 that is manufactured by turning over the directional magnetic steel sheet tile 92 , which the axis of easy magnetization Ax in the direction defined by turning the short-side direction 60 □ clockwise, so that it will have an axis of easy magnetization Ax in a direction defined by turning the long-side direction 30 □ clockwise; and a directional magnetic steel sheet tile 91 that is manufactured by turning over the directional magnetic steel sheet tile 91 , which has the axis of easy magnetization Ax in the direction defined by turning the short-side direction 30 □ clockwise, so that it will have an axis of easy magnetization Ax in a direction defined by turning the long-side direction 60 □ clockwise. These tiles are repeatedly layered so that they will exhibit a non-directional property as a whole. The directional magnetic steel sheet tiles 90 to 93 are shaped like a rectangle whose short sides are 2.5 cm long and whose long sides are 5 cm long. Incidentally, the long sides may be 5 cm or less in length. The thickness of the directional magnetic steel sheet tiles 90 to 93 is, for example, 0.35 mm. Consequently, 120 directional magnetic steel sheet tiles are layered.
[0077] [0077]FIG. 4 is an explanatory diagram showing the laminate structure of each of the marginal-portion laminate blocks 303 b.
[0078] Each of the marginal-portion laminate blocks 303 b has non-directional magnetic steel sheet tiles 94 , which are shaped like a rectangle whose short sides are 2.5 cm long and whose long sides are 5 cm long, layered. The thickness of the non-directional magnetic steel sheet tiles 94 is, for example, 0.35 mm. Consequently, 102 non-directional magnetic steel sheet tiles 94 are layered.
[0079] [0079]FIG. 5 shows a characteristic curve indicating the permeabilities which a directional magnetic steel sheet and a non-directional magnetic steel sheet exhibit with an external magnetic field applied thereto.
[0080] The strength of an external magnetic field applied to the center portion of the circular pole piece 300 ranges, for example, from 20 A/m to 60 A/m. The strength of an external magnetic field applied to the marginal portion thereof ranges, for example, from 50 A/m to 150 A/m. The permeability which the directional magnetic steel sheet tiles 90 to 93 exhibit with an external magnetic field applied thereto is twice or more larger than the permeability which the non-directional magnetic steel sheet tiles 94 exhibit with the external magnetic field applied thereto.
[0081] Consequently, the residual magnetic induction in the center portion of the circular pole piece 300 can be minimized.
[0082] The center-portion laminate block 303 a shown in FIG. 3 is manufactured as described below.
[0083] First, as shown in FIG. 6, a directional magnetic steel sheet DS is cut using a die in order to produce numerous directional magnetic steel sheet tiles 90 to 93 .
[0084] Thereafter, as shown in FIG. 3, a required number of directional magnetic steel sheet tiles 90 to 93 are layered by performing internal die caulking or the like. This results in the center-portion laminate block 303 a.
[0085] Thereafter, as shown in FIG. 7, the center-portion laminate block 303 a is immersed in an adhesive solution L. Thereafter, the center-portion laminate block 303 a is hardened and integrated for fear it may be disunited with electromagnetic force.
[0086] The marginal-portion laminate block 303 b shown in FIG. 4 is manufactured as described below.
[0087] First, as shown in FIG. 8, a non-directional magnetic steel sheet NS is cut using a die in order to produce numerous non-directional magnetic steel sheet tiles 94 .
[0088] Thereafter, as shown in FIG. 4, a required number of non-directional magnetic steel sheet tiles 94 are layered to produce the marginal-portion laminate block 303 b.
[0089] Similarly to the one shown in FIG. 7, the marginal-portion laminate block 303 b is immersed in the adhesive solution L. Thereafter, the marginal-portion laminate block 303 b is hardened and integrated.
[0090] Using the foregoing circular pole piece 300 , the residual magnetic induction in the center portion thereof located near the imaging area can be minimized. Moreover, since the maximum length of the center-portion laminate block 303 a and marginal-portion laminate block 303 b is 5 cm, the adverse effect of an eddy current caused with application of a magnetic field gradient can be minimized.
Second Embodiment
[0091] [0091]FIG. 9 is an explanatory diagram showing the laminate structure of a laminate block 303 employed in a second embodiment.
[0092] The laminate block 303 comprises: a directional magnetic steel sheet tile 90 having an axis of easy magnetization Ax in the direction of the short sides of the block; a directional magnetic steel sheet tile 91 having an axis of easy magnetization Ax in a direction defined by turning the short-side direction 30 □ clockwise; a directional magnetic steel sheet tile 92 having an axis of easy magnetization Ax in a direction defined by turning the short-side direction 60 □ clockwise; a directional magnetic steel sheet tile 93 having an axis of easy magnetization Ax in the direction of the long sides of the block; a directional magnetic steel sheet tile 92 that is manufactured by turning over the directional magnetic steel sheet tile 92 , which has the axis of easy magnetization Ax in the direction defined by turning the short-side direction 60 □ clockwise, so that it will have an axis of easy magnetization Ax in a direction defined by turning the long-side direction 30 □ clockwise; a directional magnetic steel sheet tile 91 that is manufactured by turning over the directional magnetic steel sheet tile 91 , which has the axis of easy magnetization Ax in the direction defined by turning the short-side direction 30 □ clockwise, so that it will have an axis of easy magnetization Ax in a direction defined by turning the long-side direction 60 □ clockwise; and a non-directional magnetic steel sheet tile 94 . These tiles are repeatedly layered so that they will exhibit a non-directional property as a whole.
[0093] When the laminate block 303 shown in FIG. 9 is adopted for the center-portion laminate block 303 a, it is combined with the margin laminate block 303 b shown in FIG. 4.
[0094] When the laminate block 303 shown in FIG. 9 is adopted for the marginal-portion laminate block 303 b, it is combined with the center-portion laminate block 303 a shown in FIG. 3.
[0095] The laminate block 303 shown in FIG. 9 is manufactured as described below.
[0096] First, as shown in FIG. 6, a directional magnetic steel sheet DS is cut using a die in order to produce numerous directional magnetic steel sheet tiles 90 to 93 .
[0097] Thereafter, as shown in FIG. 8, a non-directional magnetic steel sheet NS is cut using a die in order to produce numerous non-directional magnetic steel sheet tiles 94 .
[0098] Thereafter, as shown in FIG. 9, a required number of directional magnetic steel sheet tiles 90 to 93 and a required number of non-directional magnetic steel sheet tiles 94 are layered to produce the laminate block 303 .
[0099] Similarly to the one shown in FIG. 7, the laminate block 303 is immersed in the adhesive solution L, and then hardened and integrated.
Third Embodiment
[0100] The center-portion laminate block 303 a shown in FIG. 3 may be adopted as the marginal-portion laminate block 303 b. This is because in the marginal portion of the circular pole piece 300 , there is no large difference between the permeability which the directional magnetic steel sheet tiles 90 to 93 exhibit with an external magnetic field applied thereto and the permeability of the non-directional magnetic steel sheet tiles 94 .
Fourth Embodiment
[0101] The laminate block 303 shown in FIG. 9 may be adopted as the center-portion laminate block 303 a and marginal-portion laminate block 303 b alike. In this case, preferably, the ratio of the non-directional magnetic steel sheet tile 94 to the directional magnetic steel sheet tiles 90 to 93 is made relatively low in the center-portion laminate block 303 a but made relatively high in the marginal-portion laminate block 303 b.
Fifth Embodiment
[0102] A directional magnetic steel sheet may be adopted as a soft magnetic material to be made into the center-portion laminate block 303 a, and a ferrite may be adopted as a soft magnetic material to be made into the marginal-portion laminate block 303 b.
Sixth Embodiment
[0103] The combination of a directional magnetic steel sheet and a non-directional magnetic steel sheet may be adopted as a soft magnetic material to be made into the center-portion laminate block 303 a. A ferrite may be adopted as a soft magnetic material to be made into the marginal-portion laminate block 303 b.
Seventh Embodiment
[0104] An amorphous soft magnetic material or Permalloy may be adopted as a soft magnetic material to be made into the center-portion laminate block 303 a, and a non-directional magnetic steel sheet or a ferrite may be adopted as a soft magnetic material to be made into the marginal-portion laminate block 303 b.
[0105] An amorphous soft magnetic material such as Co—Nb—Zr (metal-metal series) or Co—Fe—B—Si (metal-metalloid series) may be adopted as the amorphous soft magnetic material.
Eighth Embodiment
[0106] [0106]FIG. 10 is a sectional view showing the major part of an MRI system in accordance with an eighth embodiment.
[0107] An MRI system 400 is an open MRI system. Herein, a magnetic circuit composed of permanent magnets M vertically opposed to each other, base yokes YB, support yokes YP, and circular pole pieces 300 is used to induce a static magnetic field in a vertical direction between the circular pole pieces 300 .
[0108] According to the MRI system 400 , since the residual magnetic induction in each of the center portions of the circular pole pieces 300 is limited, the adverse effect of the residual magnetic induction can be suppressed and the MRI image quality can be improved.
[0109] Incidentally, the circular pole piece in accordance with any of the second to seventh embodiments may be adopted as the circular pole pieces 300 .
[0110] Moreover, a superconducting magnet may be adopted on behalf of the permanent magnets M.
Other Embodiments
[0111] (1) In the aforesaid embodiments, the circular pole piece 300 is divided into two portions, that is, the center portion and marginal portion. Alternatively, the circular pole piece 300 may be divided into three or more portions, that is, the center portion and marginal portion, and one or more intermediate portions. In this case, a soft magnetic material permitting the highest possible permeability with an external magnetic field applied thereto should be adopted for the portions. Therefore, for example, the circular pole piece may be divided into three portions, that is, the center portion, marginal portion, and intermediate portion, soft magnetic materials having different compositions may be adopted for the respective portions.
[0112] (2) The center-portion laminate block 303 a and marginal-portion laminate block 303 b may be shaped like a square or a trapezoid.
[0113] Many widely different embodiments of the invention may be configured without departing from the spirit and the scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claim.
|
The object of the present invention is to minimize the residual magnetic induction in a circular pole piece included in a magnetic circuit for magnetic resonance imaging. A circular pole piece is divided into two portions, that is, a center portion and a marginal portion. A soft magnetic material that exhibits a high permeability (for example, 10000 or more) with a relatively small external magnetic field (for example, ranging from 20 A/m to 60 A/m) applied thereto is adopted as a soft magnetic material to be made into a center-portion laminate block. A soft magnetic material that exhibits a high permeability (for example, 6000 or more) with a relatively large external magnetic field (for example, ranging from 50 A/m to 150 A/m) applied thereto is adopted as a soft magnetic material to be made into a marginal-portion laminate block 103 b. Consequently, since the residual magnetic induction in the circular pole piece can be minimized, the degradation in image quality attributable to a residual magnetic induction can be prevented.
| 6
|
FIELD OF THE INVENTION
[0001] The present invention relates to a kind of capsule endoscope, and more particularly to the control method for a kind of capsule endoscope with memory storage device.
BACKGROUND OF THE INVENTION
[0002] Since 1975 many medical scholars have been engaging in the examination of digestive system. Under the situation where the examining equipment is more primitive and inconvenient, usually on the front and back portion of the digestive system can be examined. Subsequently, for the improvement of ease in examination, there is the conception and invention of endoscope. The American company called Welch-Ally invented electronic endoscope in 1984. With advances in the hi-tech industry, there are also significant improvement and progress in endoscope and evolves to the apparatus of endoscope examination today. This refers to the traditional endoscope, meaning a piece of long black tube. One end of the tube is connected to the machine. This machine could produce cold light source. The tube has optical fiber inside and could transmit the cold light to the other end of the tube through optical fiber. During examination, a tube is inserted into the organ to be examined. The cold light transmitted from cold light source could light up the inside of the organ. The optical sensor chip (CCD, similar to DV or V8 video recorder) fixed at the end of the tube could send the clear image signal back to the machine. The computer in the machine will convert the signal into image. In this way, we could see the inside of the organ just as watching TV. The doctor will then control the direction of the tube (traditional endoscope) to the left, right, or moving forward and easily maneuver the area intended to see. However, there is still a large section of the intestine that could not be easily checked with endoscope. This is because if the length of the endoscope is too long, it is harder to maneuver, and patent has to endure more pain. This is clearly not a good method of examination.
[0003] With the advances in technology, a technique using biological wireless remote control is gradually being developed and abandoning the prior wired transmission. The size and method of usage are also being resolve to overcome the drawback of the present endoscope. In recent years, with the invention of energy saving and miniaturizing of optical sensor chip, there is the birth of small size capsule endoscope. Such capsule endoscope refers to the size of optical sensor chip for photographic camera and the cold light source are shrunk to the size of capsule pill with the dimension of 11×26 mm. Except for the optical sensor chip inside, there are small battery, LED, and computer chip and radio transmitter. The camera can take two pictures every second. The examination time is about 8 hours each time. A total of 50,000 pictures can be taken. The endoscope, same size of a capsule, is swallowed into the stomach. Inside the body, the capsule advances with the movement of the intestine. Meanwhile, the optical sensor could take pictures at the same time to obtain the image of interior of the organ. The image signals obtained by the optical sensor chip is transmitted to outside of the body through the use of radio apparatus. We will set up 9 pieces of radio antenna on the abdomen of the person receiving examination, and store the received signals in the portable receiver. The capsule endoscope will then faithfully recording all the images it takes from esophagus all the way through small intestine till the large intestine until it runs out of battery. Finally, the endoscope is discharged through the anus with stool and concludes the whole examination mission. In this way, it is very convenient to examine a patient.
[0004] However, the cost involved in the installation of capsule endoscope and its peripheral devices for wireless transmission is very expensive, and specialist personnel are required to install large size of antenna and receiving storage device on the person being examined in order to receive image information. Such process is quite complicated, and it is quite inconvenient to move around for the person being examined with such large volume of antenna and receiver. This makes it harder to promote the use of such capsule endoscope system.
[0005] Besides, the antenna is stuck to the person receiving the examination for the collection of data, which will have the problem of sensitivity of receiving. For example, the one-meter range between intestine and pylorus is less sensitive for the capsule endoscope to transmit radio information.
[0006] As to the accuracy aspect, as the frequency required for the radio transmission in human body is in low frequency, it is not possible to use large width of information for the transmission. Thus, the number of pictures transmitted and resolution is greatly restricted. As the information could not be transmitted in large amount, it is not possible to transmit larger number of pictures. For instance, in the area of esophagus where the movement is faster, at most two pictures per second can be transmitted. Some data can be lost if the setup is moving too fast. In addition, such setup cannot be installed with too many photo sensor chips for the capturing of more image data and leaving more data for the doctor to make the judgement. If two (or more) optical sensor can be installed on the front and back sides of the capsule endoscope in the geometrical method, it is possible to obtain about 360 degrees of image on the surrounding of capsule endoscope. Thus it is possible to drastically increase the information of images and increase the accuracy of doctor's interpretation of data.
[0007] In view of this, this invention is a kind of control method for capsule endoscope with memory storage device in order to resolve the problems of the traditional technology.
SUMMARY OF THE INVENTION
[0008] A primary object of the present invention is to provide a control method for capsule endoscope with memory storage device; a unidirectional wireless receiving module is added to the internal of the capsule endoscope for receiving external instructions in order to adjust the movement of the capsule endoscope so ask to achieve certain particular sampling task and further to drastically increase the accuracy of examination.
[0009] Another object of the present invention is to provide a wireless unit for sending unidirectional instruction to the capsule endoscope, which is a very small size magnetic material that is harmless to human body, or low frequency, low power unidirectional wireless unit for sticking to the person's body that instructions must be sent to the capsule endoscope, on receiving the instruction what the form of action pictures must be taken in order to achieve certain particular sampling tasks.
[0010] Still another object of this invention for expanding other testing units inside the capsule endoscope in order to obtain other testing information for the purpose of securing more information to increase doctor's judgement and sending instructions to the capsule endoscope to activate or stop the examination device by using the control method described above.
[0011] To achieve the above objects, this invention is to swallow the endoscope the size of a capsule into the stomach. Inside the stomach, the capsule endoscope will advance with the movement of the intestine. The capsule endoscope itself will flash at the rate of two times per second so that the optical sensor chip could take the picture at the same time to obtain the image of interior of organs. The image signals obtained from the optical sensor chip will be written into the memory storage device at very high speed. The capsule endoscope will then record all pictures taken inside the stomach faithfully until the battery runs out of power. Then, it will be discharged through anus with stools and conclude the whole inspection mission. However, before such examination can be carried out, special requirement must be followed and the person's body must be stuck with different “wireless transmitting units”. When the capsule endoscope receives an instruction, it will immediately adjust the movement of capsule endoscope in order to accomplish certain special sampling tasks.
[0012] On completion of the examination, the capsule endoscope discharged will be cleaned and sterilized. The shell of the capsule will be cut open and the host interface of this device will be connected to the terminal host. The controller of the capsule endoscope will communicate with the terminal host through the host interface. On turning on of power, the controller will read from the information block of SRAM into the controller. Based on the data downloaded from the information block of the SRAM, the controller will respond based on the request of the host and configure the memory module and regards it as logical disk. The host could access all pictures taken freely through the logical disk.
[0013] Below will further explain through the attached diagram of the embodiment in order to understand the object of this invention, description of technology, features, and the performance achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is the illustration of the embodiment of the newly added wireless receiving module capsule endoscope with build-in memory storage device;
[0015] FIG. 1A is the 3D diagram of the newly added wireless receiving module of the capsule endoscope with memory storage device of this invention;
[0016] FIG. 2 is the illustration of the state of the capsule endoscope of this invention in operational control;
[0017] FIG. 3 is the illustration of the state of this invention in connection with a terminal host.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] For the ease in understanding other characteristics of this invention and the advantages as well as to exemplify the achieved performance for the auditing committee. This invention together with the illustration is described in detail as shown below.
[0019] Capsule endoscope containing large amount of storage device is using the controller to integrate optical sensor chip (contains focusing lens) and memory module. The method of data bus interface is used to read the image data of optical sensor chip controlled by the controller, then use very high speed to write into the memory module on the same data bus and further to drastically increase the number of pictures processed per second. Here there could be more optical sensor chips combined to take 360 degrees image. In this way, it is possible to increase the information of the image and increase doctor's read-out accuracy.
[0020] However, as there is limitation in the size of capsule endoscope and the electrical power stored, a method that could efficiently utilize the limited power and memory of the endoscope is needed in order to achieve maximum benefit and most information to help doctor in reading the data.
[0021] On the other hand, capsule endoscope using this new structure could cause the controller to integrate other testing unit (such as acid and alkaline value testing device) in additional to the optical sensor chip (containing focusing lens) and then directly write the newly added testing information from controller to memory module. After the testing is completed and the device is discharge from the body, the terminal host is used to download the pictures taken and the additional information in order to provide rich information for doctor to read-out.
[0022] Please refer to FIG. 1 that is the illustration of the embodiment of the present invention of capsule endoscope with newly added wireless receiving module containing memory storage device. FIG. 1A is the 3D illustration of the capsule shell of the capsule endoscope containing memory storage device with newly added wireless receiving module. FIG. 2 is the illustration of the state of the capsule endoscope in the control operation of this invention, and FIG. 3 is the illustration of the connecting state of this invention with a terminal host. As shown in these figures, the capsule endoscope with memory storage device has a memory interface 110 containing a controller 102 , a memory module 104 , an LED 105 , an optical sensor chip 106 (containing focusing lens), a wireless receiving module 107 , a battery pack 109 providing power, and the acid-alkaline resisting capsule shell 130 for enclosing the above stated components (picture taking opening is transparent) and a host interface 108 .
[0023] The task of controller 102 is to communicate with terminal host 100 and at the same time manage memory module 104 , LED 105 , optical sensor chip 106 (contains focusing lens), and wireless receiving module 107 . Memory module 104 must contain at least one storage chip or memory for storing information, such as flash memory, PROM, or any EPROM; when activating the power of the battery pack 109 in the device, the controller 102 will start to drive LED 105 and optical sensor chip 106 (contains focusing lens) and engage in the photographing process and at the same time store the images taken into memory module 104 ; controller 102 at the same time also receives the state changes or information from wireless receiving module 107 in order to obtain the instructions given externally and then changes the current operating mode of controller 102 so as to meet the operating mode intended externally; if the esophagus is 90 degrees vertical, the image of esophagus almost unable to obtain effectively. If this device could activate two cameras since the beginning to take images of almost 360 degrees and at the same time the number of pictures taken is increased to more than 10 pieces, then all images in the esophagus will all be taken without miss even if moving in high speed in the esophagus; and we stick a “recovering” wireless transmitting unit 200 (not illustrated in the figure) at the connection between esophagus and stomach initially. On receiving instruction from capsule endoscope, it will immediately adjust the action of capsule endoscope immediately and recover back to taking two pictures each second. In this way, it is possible to reduce power consumption, safe storage space, and at the same time satisfy the requirement of certain portion need to secure more information.
[0024] Controller 102 will manage memory module 104 at the same time and store the several images taken into one picture file; then the capsule endoscope will faithfully record all pictures taken in the stomach all the way from esophagus to small intestine or even to large intestine until the battery runs out and discharged with stool from anus and conclude the whole examining task.
[0025] Then, the discharged capsule endoscope will be cleaned and sterilized, the capsule shell 130 is cut open, and the host interface 108 of the device is connected to the terminal host 100 . The controller 102 in the capsule endoscope communicates with the terminal host 100 through the host interface 108 . Controller 102 on connecting to terminal host 100 and obtaining the power will read the information block into the SRAM of controller. According to the information block information loaded into SRAM, controller 102 will react to the request issued by the terminal host 100 and configure the memory module, and treat it a logical disk. The host will access all image files freely through the logical disk. The application software in the terminal host 100 will operate in multiplex mode and retrieve all image files of memory module 104 , at the same time it will display the retrieved image file on the display instantly, and save or make into CD file after processing the displayed image file.
[0026] In addition, the controller 102 can further integrate with some other test unit 120 other than optical sensor chip such as acid or alkaline testing device and then directly write the newly added acid or alkaline testing value into memory by the controller 102 . When the testing is completed the device is discharged out of the body and the terminal host 100 is used to download the images taken and the testing information of the added acid and alkaline values so as to provide rich information for doctor's read-out.
[0027] To achieve the object of the above stated invention, this invention is to swallow the endoscope the size of a capsule into the stomach. In the stomach, the capsule endoscope will advance with the movement of the intestine, and the capsule endoscope itself will flash twice per second. At this time, the optical sensor chip will take pictures at the same time to obtain the images inside the organ and use very high speed to write the image signals obtained by the optical sensor chip into the memory storage device. Then, the capsule endoscope will faithfully record all pictures taken in the stomach from esophagus all the way to the small intestine or even to the large intestine until finally the battery runs out of power and discharged from anus with stool and conclude the whole examining mission. However, before executing the test, special requirement can be followed and then sticks different “wireless transmitting units” on the body. When the capsule endoscope actually receives instruction, it will adjust the action of the capsule endoscope instantly in order to achieve certain particular sampling task. On completing the test, the capsule endoscope is cleaned and sterilized before the capsule shell is cut open and connected to the terminal host through the host interface. After turning on the initial power, the controller will read the information block into the SRAM of controller. Based on the information block data is loaded into SRAM, the controller will respond to the request from the host and configure the memory module and treat it as the logical disk. The host will access all pictures freely through the logical disk.
[0028] In summary, this invention has achieved breakthrough under the prior technical structure and indeed has achieved all intended effect and is not easy for person familiar with the art to think of. In addition, the application of this innovation has never be opened, and the advances, the practicality of this invention obviously has meet the requirement of applying for invention patent. Therefore, the invention is applying based on the law and request your authority to grant the invention patent application for encouraging the innovation. We are appreciative of your approval.
[0029] The embodiment stated above is for explaining the thinking and features of this invention. Its purpose is for the people skilled in this art to understand the content of this invention and implement accordingly. It certainly is not limited to the range of the patent of this invention. All equivalent variations or modifications based on the spirit revealed by this invention shall be covered in the patent of this invention.
|
The object of the present invention is to reveal how to control the operation of a capsule endoscope that has a memory storage device. The capsule endoscope is swallowed through the mouth to start the photographic inspection. During the process of operating the capsule endoscope, the built-in wireless receiving module is used to receive instructions and further to adjust the movement of capsule endoscope in order to achieve the inspection tasks; on completion of the photographic inspection, the capsule shell is cut open and connected to the host computer, and the image and data stored in the storage module are accessed through the host computer.
| 0
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is related to a method and a device for laterally aligning a lateral edge of flat material webs fed to a machining station, in which the lateral position of the lateral edge is detected transversely to a feed direction under formation of a position signal and in which the flat material webs are moved transversely to the feed direction as a function of the position signal.
2. Description of the Related Art
Methods of this type are predominantly deployed in automatic sewing machines, where it is important due to high processing speeds that the material edge is automatically guided along a predetermined path. In order to achieve this it is known (EP-B-0 383 045) to use a chain of spherical or crowned roller elements for the transverse transport, which chain can be adjusted in a plane extending approximately transversely to the sewing direction in its longitudinal direction as a function of the position signal and which lies against the material web with a plurality of roller elements having roller axes extending parallel to the aligning direction. The crowned roller elements have a rough or profiled surface structure in order to increase their frictional properties, which can lead to undesirable distortion or damage especially of fine silk or cotton materials.
SUMMARY OF THE INVENTION
Based on this it is the object of the invention to develop a method and a device of the type described above, which ensures a non-damaging yet dependable handling during the lateral alignment of the flat material webs.
The solution according to the invention is based on the idea that two elongated cylindrical friction rollers, the rotational axes of which are aligned transversely to the feed direction, are used to effect the transverse transport, which rollers are alternatingly pressed on the one hand against the flat material web and moved back-and-forth in the direction of their rotational axes between two extreme positions as a function of the position signal, thereby taking along the flat material web, while on the other hand the other roller is lifted off from the flat material web, a change of rollers being triggered whenever the extreme positions are reached. These measures have the advantage that the frictional rollers contact the flat material webs along a greater width, so that no unwanted indentation or distortion of the flat material surface can occur during the transverse transport. A further improvement in this respect is attained when the friction rollers have a surface coating consisting of elastic, preferably rubber-elastic material.
A further improvement in this respect is attained when the transverse transport is stopped during a change of rollers, which can be performed comparatively quickly with suited drive means. This is of importance especially when both friction rollers are momentarily pressed against the flat material web during a change of rollers. The transverse transport after a change of rollers can initially be continued with the substituted roller in the same direction as before the change of rollers. Advantageously, the transverse transport is slowed down by suited drive means when approaching the extreme positions, so that only small accelerating forces occur during the stopping and starting of the transverse transport. The active friction roller is pressed against the flat material web under the action of a preferably adjustable spring force.
An especially advantageous and easily realized embodiment of the invention provides that the two friction rollers are moved, by means of a motor, in opposing directions during the transverse transport and a change of rollers. Both friction rollers are expediently brought into a predetermined starting position, for example a centered position between the two extreme positions, before activation of an aligning process. Further, one of the two friction rollers is brought into contact with the flat material web.
The device for implementing the method according to the invention, which comprises a sensor array for detecting the lateral position of the lateral edge transversely to the feed direction and a transverse transport device which acts upon the flat material web and which is triggered by a position signal taken from an output of the sensor array, has, according to the invention, two cylindrical friction rollers which are adapted to rotate about axes which are aligned transversely to the feed direction, of which rollers one is alternatingly pressed against the flat material web and moved back-and-forth in the direction of the rotational axes between two extreme positions as a function of the position signal, thereby taking along the flat material web, while the other roller is lifted off from the flat material web, a change of rollers being triggered by an extreme position signal whenever one extreme position is reached.
According to a preferred embodiment of the device according to the invention the transverse transport device comprises a change mechanism which reacts to the extreme position signals and which alternatingly moves the friction rollers against and away from the flat material web, as well as two extreme position switches, preferably formed to be proximity switches, for generating the extreme position signals.
The two friction rollers are advantageously adapted to be moved opposingly back-and-forth in the direction of their rotational axes. In order to be able to securely hold the flat material web in the feed direction even during a change of rollers, it is suggested according to a preferred embodiment of the invention that both of the two friction rollers momentarily contact the flat material web at each change of rollers, the transverse transport being stopped at this time. The transverse transport as well as a change of rollers are triggered by means of a micro-computer controlled control device as a function of the measure position signals and extreme position signals.
A particularly simple construction of the device according to the invention provides that the transverse transport device comprises a frame part, two transverse slides which are adapted to be opposingly moved with respect to the frame part by means of a motor, and two changing slides which each carry one of the friction rollers and which each are adapted to be opposingly moved perpendicular to the transverse and feed direction on one of the transverse slides. Alternatively it is possible to position the friction rollers on the transverse slide, when two changing slides which are adapted to be opposingly moved perpendicular to the transverse and feed direction with respect to the frame part, and two transverse slides which each are adapted to be opposingly moved in the transverse direction on one of the changing slides by means of a motor are provided. The transverse slides are advantageously adapted to be driven in opposing directions by means of a common stepper motor and an eccentric transmission. The eccentric transmission can comprise a roller bearing which is formed to be an eccentric disc and which engages a gate of the transverse slide and/or of the changing slide.
The changing slides are expediently adapted to be driven in opposing directions by means of a common, preferably pneumatic torque motor and a further eccentric transmission against the force of a spring force which acts in the direction of the flat material web. By this it is attained that the friction rollers are pressed, under the action of the spring force and the further eccentric transmission being disengaged on the side of the changing slides, against the flat material web which is adapted to moved relative to a base. In order to ensure that both friction rollers momentarily contact the flat material web during a change of rollers the further eccentric transmission on the side of the changing slides has an end-play angle initiating from the contact position of the corresponding friction roller, which ensures that during a change of rollers the friction roller contacting the web under the action of the spring force is lifted off from the web after a time-delay, after the other friction roller already has made contact with the web. The machining station is advantageously formed to be a sewing head of an automatic sewing machine and the flat material web is formed to be a textile web. Other applications of the invention are also feasible, though, as for example in feeding paper webs, plastic webs or sheet metal webs to machining centers.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following the invention is further explained with reference to the accompanying drawing, in which:
FIG. 1 shows a side view of a detail of an automatic sewing machine having an edge control;
FIG. 2 shows a front view of a detail of the transverse transport device of FIG. 1;
FIG. 3 shows a schematic view of a sensor array for detecting the lateral edge position;
FIG. 4 shows an exploded view of the transverse transport device of FIG. 1;
FIG. 5 shows a flow chart of a computer program for edge control.
DETAILED DESCRIPTION OF THE INVENTION
The automatic sewing machine shown in FIG. 1 is used for sewing a textile web 10 near its edge. To this end the textile web is fed to the sewing head 16 in the direction of the arrow 14 on a web support part 12 of the sewing machine. The sewing head is pressed against the web 10 with a contact foot 18. A sensor array is disposed--in the feed direction 14--in front of the sewing head, which sensor array comprises in the embodiment shown two laterally spaced photoelectric barriers 22, 24 disposed in the region of the lateral edge 26 of the passing web 10. The outputs 22', 24' of the photoelectric barriers 22, 24 are connected to a computerized control device 28 by means of signal lines 22", 24".
In front of the sewing head 16 a transverse transport device 30 is additionally provided, which is triggered by the control device 28 for the lateral alignment of the lateral edge 26 of the web in the feed direction 14 as a function of the position signals supplied by the photoelectric barriers 22, 24. To this end the transverse transport device 30 has two cylindrical friction rollers 32, 34 which are freely rotatable about their axes 32', 34' which are aligned transversely to the feed direction 14, of which rollers alternatingly one friction roller 32 contacts the web 10, while the other friction roller 34 is lifted off from the web 10. The two friction rollers 32, 34 are opposingly movable back-and-forth in the direction of the double arrows 32", 34" (FIG. 2), wherein the friction roller in contact with the web 10 is movable back-and-forth, taking along the web 10, between two extreme positions as a function of the position signal emitted by the photoelectric barriers 22, 24. Upon reaching the extreme positions an extreme position signal is generated by the proximity switches 36, 38, which signal is fed to the control device 28 via signal lines 36', 38'.
The transverse movement of the friction rollers 32, 34 is effected by a stepper motor 40 which is actuated via the output line 40' of the control device 28 as a function of the position signals supplied via the signal lines 22", 24".
A change of rollers is effected by means of a pneumatic torque motor 42 which is triggered via the output line 42' of the control device 28 when an extreme position signal is detected at one of the signal lines 36', 38'. During this process the friction rollers 32, 34 are moved in opposite directions in the direction of the double arrows 32'", 34'" against and away from the web (FIG. 2). With the linear motor or stroke cylinder 44, which is additionally provided on the frame 43 and which is triggered by way of the output line 44' of the control device 28, the transverse transport device 30 as a whole can be lifted off from or pressed against the thrust roller 46 of the sewing machine. The friction rollers 32, 34 can only be activated when the transverse transport device 30 is in the position in which it is pressed against the thrust roller.
As can be seen from the schematic exploded view of FIG. 4, the transverse transport device 30 essentially consists of a frame part 48, two transverse slides 50, 52 which are adapted to be opposingly moved with respect to the frame part 48 in the direction of the arrows 32", 34" by means of a motor, and two changing slides 54, 56 which each carry one of the friction rollers 32, 34 and which each are adapted to be opposingly moved on one of the transverse slides 50, 52 in the direction of the arrows 32'", 34'". In this, the transverse slides 50, 52 are moved in the direction of the arrows 32", 34" by the driven shaft 40" of the common stepper motor 40 and the eccentric transmission 58, while the changing slides 54, 56 are moved by the driven shaft 42" and the further eccentric transmission 60 against the force of the compression springs 54', 56' which push in the direction of the web.
The eccentric transmission 58 for the transverse slides 50, 52 comprises two eccentric discs 62 which are formed to be deep groove ball bearings, which engage in the gates 64 of the transverse slides 50, 52 and which are moved in opposing directions by means of the eccentric journals 66 of the drive discs 68 driven by the stepper motor 40.
The further eccentric transmission 60 comprise two drive dics 72 which are concentrically supported in gates 70 of the transverse slides 50, 52, the sliding blocks 74, which protrude in opposing directions, of which drive discs engage in the gate openings 76 of the changing slides 54, 56. The sliding block 74 lies against the frame leg 76' of the gate opening 76 in the position shown in the left part of FIG. 4, and lifts the corresponding changing slide 56 together with the friction roller 34 off from the web 10 against the force of the spring 56', while it is lifted off from the gate leg 76' of the gate 76 in the position shown in the right part of FIG. 4, so that the corresponding changing slide 54 and the friction roller 32 lie against the web 10 under the action of the spring 54'.
When a change of rollers is performed, the sliding block 74 initially rotates in the gate 76 of the right changing slide 54 about a certain dead angle, until it contacts the leg 76' and lifts up the changing slide 54 against the force of the spring 54'. During this time the friction roller 32 remains in contact with the web 10, while the other changing slide 56 with the friction roller 34 is moved, under the action of the spring 56', against the web 10 by the corresponding gate leg 76' during the rotation of the drive disc 72 and lifting off of the sliding block 74.
The program during the edge control is shown in the flow chart of FIG. 5 and executed as follows:
When the program is started the transverse transport device 30 is first brought into a predetermined neutral position, in which the two friction rollers 32, 34 are centered between the two extreme position switches 36, 38 and the friction roller 32 is extended by actuation of the corresponding changing slide 54. The transverse transport device 30 is then brought by actuation of the linear motor 44 into a position in which it is extended against the thrust roller 46.
After the activation of the edge control, for example by a web 10 fed to the sensor array 20, the edge position is detected by the photoelectric barriers 22, 24. The branch "yes" is followed when one photoelectric barrier is open and the other is closed (cf. FIG. 3). When this condition is not met anymore (branch "no"), it is determined by way of the photoelectric barriers 22, 24 whether there is too little (both barriers open) or too much (both barriers closed) material present. In the one case material is added and in the other case material is removed by means of the stepper motor 40 and the active friction roller 32, 34, and a new cycle is started via the extreme position switch output, as long as one of the two extreme position switches has not yet been reached.
When one or the other extreme position switch is reached (Branch "yes"), the stepper motor 40 is stopped and the pneumatic torque motor 42 is triggered to effect a change of rollers. After the change of rollers has been performed, the stepper motor 40 is activated in the opposite direction, so that material is added or removed in the previous direction by means of the substituted roller.
The program execution is interrupted when the edge control is deactivated, for instance by an end-of-web signal.
In summary the following is to be stated: The invention is related to a method and a device for laterally aligning a lateral edge of flat material webs 10 fed to a machining station 16. In this the lateral position of the lateral edge 26 is detected transversely to a feed direction 14 under formation of a position signal and the flat material webs 10 are moved transversely to the feed direction 14 as a function of the position signal. According to the invention, two elongated cylindrical friction rollers 32, 34, the rotational axes 32', 34' of which are aligned transversely to the feed direction 14, are used to effect the transverse transport, which rollers are alternatingly pressed on the one hand against the flat material web 10 and moved back-and-forth in the direction of their rotational axes 32', 34' between two extreme positions as a function of the position signal, thereby taking along the flat material web 10, while on the other hand the other roller is lifted off from the flat material web 10, a change of rollers being triggered whenever the extreme positions are reached.
|
The invention concerns a method and device for laterally aligning a lateral edge of flat material webs (10) fed to a machining station (16). The lateral position of the edge (26) transversely to the feed direction (14) is detected, so that a position signal is formed and the flat material web (10) is conveyed transversely to the feed direction as a function of this position signal. According to the invention, the transverse conveying, two elongate cylindrical friction rollers (32, 34), whose axes of rotation are aligned transversely to the feed direction (14), are first alternatively urged against the flat material web so that they entrain the flat material web (10) in the sense of their axes of rotation (32', 34') and, as a function of the position signal are moved in a reciprocating manner between two end positions and, secondly are raised off the flat material web, the change of rollers being triggered whenever the end positions are reached.
| 3
|
TECHNICAL AREA
[0001] The present invention concerns a method for the continuous cooking of cellulose according to the introduction to claim 1 with the aim of achieving improved heat economy during impregnation with black liquor.
THE PRIOR ART
[0002] The technique of impregnation with black liquor was developed during the latter part of the 1980s and the 1990s, as part of the development of processes for continuous cooking, with the aim of obtaining improved cooking economy and heat economy and of obtaining better pulp. impregnation with black liquor is characterised in that the impregnation fluid is partially or fully constituted by withdrawn cooking fluid, known as black liquor, from various locations in the digester, with a higher level of residual alkali than previous cooking processes in which withdrawn cooking fluid was passed on for recovery of chemicals. The principal aim of impregnation with black liquor is to obtain pulp with a higher quality than that of pulp that is manufactured with impregnation with white liquor, while a further aim is to preserve to a greater degree the heat of the black liquor withdrawn from the digester in order to heat the cold chips in the impregnation vessel. A certain amount of the heat of the black liquor had previously been retained in the cooking process such as steam, known as flash steam, from the flash cyclones, which was used, among other purposes, for steaming the chips.
[0003] A continuous cooking process is revealed by U.S. Pat. No. 5,192,396 in which black liquor from the digester is fed indirectly to the top and bottom of the impregnation vessel via flash cyclones. The impregnation vessel is provided with an upper concurrent impregnation zone and a lower countercurrent impregnation zone. The black liquor that is transferred to the bottom of the impregnation vessel is mixed with the return flow of the transfer circulation and passed through a heat exchanger in which the temperature is raised to boiling point before the liquor is lead into the bottom of the impregnation vessel. The aim of the method is to obtain a higher ratio of fluid to wood at the bottom of the impregnation vessel and at the inlet to the digester, something that has a positive influence on the downward motion of the column of chips at the top of the digester, while at the same time the concentration of alkali in the digester becomes lower, which reduces the initial breakdown of carbohydrates during the cooking process.
[0004] A second method for the optimisation of the ratio of fluid to wood in impregnation vessels and in digesters is revealed in U.S. Pat. No. 5,679,217. The liquor in the transfer circulation is separated into a part at the top separator of the digester and a remainder in a strainer section lower in the digester. This return liquor is led collected through a heat exchanger for heating back to the outlet arrangement at the bottom of the impregnation vessel. A subcurrent of this impregnation liquor, however, is led without heating to the top of the impregnation vessel such that an increased ratio of fluid to wood is obtained at the top of the impregnation vessel. The method allows a lower ratio of fluid to wood to be obtained in the upper part of the digester than that which is obtained if black liquor from a strainer section lower in the digester is used to increase the ratio of fluid to wood according to U.S. Pat. No. 5,192,396. The advantages, according to the patent, include the ability to decrease the degree of packing at the top of the digester without a disadvantageous influence on the transfer of chips between the impregnation vessel and the digester, and the fact that the flow of steam for heating at the top of the digester can be reduced somewhat, since the temperature of the transfer becomes higher.
[0005] A method for impregnation with black liquor is known through U.S. Pat. No. 5,716,497 in which a certain amount of black liquor from the digester is mixed with the return liquor from the transfer circulation between the impregnation vessel and the digester without any cooling taking place before this mixture is supplied to the bottom of the impregnation vessel. Part of this mixture will return with the impregnated chips in the transfer circulation and the remainder will be carried in a countercurrent flow up through the impregnation vessel and will be withdrawn at a strainer section at the upper part of the vessel during heating of the chips and expulsion of wood moisture and steam condensate from the chips. Regulation of the amount of black liquor supplied to the bottom of the impregnation vessel allows a thorough impregnation to be ensured, and this can be controlled by maintaining the temperature of the material withdrawn from the strainer section at the upper part of the impregnation vessel warmer than the mixture of chips and fluid that is fed in at the top of the impregnation vessel. All white liquor is, according to the patent, added in batches at the top of the digester, which allows expensive central pipes to be avoided. A flurther advantage of the method is an improvement in the quality of the pulp since the cellulose fibres are not weakened by mechanical treatment of the bottom scraper during output from the impregnation vessel, a weakening which is considerable when white liquor is used as impregnation fluid. A method with the same aim is presented in U.S. Pat. No. 5,824,187, being a Continuation in part of the above patent, in which impregnation with black liquor takes place in a concurrent flow and without any mixing of the transfer circulation with this black liquor.
[0006] A process for continuous cooking with black liquor impregnation is revealed in U.S. Pat. No. 6,123,807, one aim of which is to obtain an improved heat economy. The black liquor withdrawn from the digester is transferred to a first flash cyclone and subsequently onwards to the beginning of the impregnation zone in order to constitute impregnation fluid either in an impregnation vessel in a two-vessel digester, or to an impregnation zone at the top of a digester in a one-vessel digester. The flash steam obtained from the flash cyclone is used to directly heat the white liquor that is added to the cooking process. The “impregnation fluid” is withdrawn after the impregnation zone for transport to recovery of chemicals via a second, and possibly also a third, flash cyclone. Although the method does give a better heat economy than known methods, heat losses still take place in those stages that lead to a reduction in temperature, and thus there exists a potential for further improvements in this respect.
[0007] A continuous cooking process is revealed in U.S. Pat. No. 5,089,086, the main aim of which is to improve heat economy. However, this is not a process for impregnation with black liquor. The process is characterised in that essentially all hot liquor withdrawn from the digester is used to transport the impregnated chips from the bottom of the impregnation vessel to the top of the digester. The hot liquor withdrawn from the digester is led, possibly without previous reduction in pressure and the fall in temperature that accompanies it, into the bottom of the impregnation vessel into a mixing zone where it is mixed with impregnated chips and impregnation fluid for transport to the top of the digester. The temperature of the chips and the fluid can in this way be raised, reducing the need of heating at the top of the digester in order to obtain the correct cooking temperature. Part of the transport fluid is separated from the conventional top separator to a flash cyclone where part of the transport fluid is returned, following reduction in pressure, together with the liquor that has been withdrawn, to the bottom of the impregnation vessel. The pressure of the remainder of the transport fluid, which corresponds to the amount of cooking fluid withdrawn, is subsequently reduced in further stages, such that the fluid can be taken away for recovery of chemicals. Thus the problem of too high a temperature of the impregnation fluid does not arise in this case. Neither is it indicated that it would be desirable to retain the heat in any other method than as flash steam in the transport fluid that is led to chemical recovery following its separation from the chip mixture in the top separator at the top of the digester.
[0008] As the description of the prior art given above makes clear, impregnation was initially often carried out with at least a final zone of countercurrent flow. Black liquor at a high temperature, typically over 140° C., was often added at this location, in order to obtain in this manner rapid heating of the chips. A high temperature was considered to be an advantage in the older methods of black liquor impregnation such that the impregnation should take place rapidly and become efficient. It was considered that impregnation in countercurrent flow was particularly advantageous for a thorough impregnation. The temperature of the transfer could, at the same time, be maintained at a high level whereby the need for heating at the top of the digester was reduced. The trend in recent years has been towards impregnation at lower temperatures and with a greater part of the impregnation taking place with a concurrent flow. This has involved the need for cooling of the black liquor from the digester which has occurred either through flashing and/or through cooling in a heat exchanger. A lower temperature during impregnation produces the need to heat the chips when they pass onwards to the digester. This has been achieved using heaters in the transfer circulation. Unavoidable energy losses arise during indirect heat transfer and it is thus desirable to discover methods that allow impregnation at low temperature where the heat in the black liquor can be preserved for use in the digester without these energy losses arising, or at least being minimised. Hot black liquor can, with the aim of improving the heat economy during the cooking process, be introduced into the bottom zone of the impregnation vessel in order to raise the temperature of the chips before the digester, something that is revealed in U.S. Pat. No. 5,089,086. However, impregnation takes place in this case using a fluid other than black liquor, which fluid must be heated in order to obtain the correct temperature.
BRIEF DESCRIPTION OF THE INVENTION
[0009] There is offered through the present invention a method for the continuous cooking of cellulose in a two-vessel digester system in which impregnation takes place in an impregnation fluid that consists at least partially of black liquor. The method makes impregnation at low temperatures possible, something that is in line with the latest developments within the technology of black liquor impregnation, while at the same time the requirement for cooling of the black liquor for the impregnation vessel is reduced or eliminated. The method also reduces or eliminates the requirement for heating in the transfer line between the impregnation vessel and the digester, which indirectly reduces the consumption of clean steam or flash steam, which can thus be used for other purposes, and it reduces the requirement for the addition of steam at the top of the digester in order to rapidly raise the temperature of the chips to cooking temperature. The method ensures an improved heat economy relative to that which is previously known in that the energy losses that unavoidably arise during heat exchange, flashing, etc., are lower. This is achieved with a method according to claim 1.
[0010] The method is applied in one preferred embodiment such that the requirement for coolers of black liquor and the requirement Qf heaters for the transfer are both eliminated, and in this way a further aim is achieved in that the cost of a digester system according to the invention will be lower than previously known systems. The cost will be lower also in an non-optimal embodiment with lower cooking and heating requirements, since these heaters and coolers can be made considerably smaller, and thus cheaper. Further properties and aspects, together with advantages, of the invention are made clear by the attached claims and the following detailed descriptions of some embodiments.
DESCRIPTION OF DRAWINGS
[0011] [0011]FIG. 1 shows schematically one preferred embodiment of a two-vessel digester in which the invention is applied.
[0012] [0012]FIG. 2 shows schematically an alternative embodiment of a two-vessel digester in which the transfer system comprises a high-pressure feederfeeder.
[0013] [0013]FIG. 3 a shows a two-vessel steamlfluid phase digester.
[0014] [0014]FIG. 3 b shows in further detail a top separator for the separation of chips and transport fluid at the top of the digester.
[0015] [0015]FIG. 4 a shows a two-vessel hydraulic digester.
[0016] [0016]FIG. 4 b shows in further detail the strainer section for the separation of chips and transport fluid at the top of the digester.
DETAILED DESCRIPTION OF THE INVENTION
[0017] [0017]FIGS. 1 and 2 show schematically a continuous two-vessel digester for the manufacture of cellulose pulp in which the invention is applied and in which the digester system comprises an impregnation vessel ( 1 ), a digester ( 2 ) and a transfer system ( 4 ) for transport of chips from the impregnation vessel ( 1 ) to the digester ( 2 ). The difference between FIG. 1 and FIG. 2 is constituted by the fact that the transfer system ( 4 ) in FIG. 2 comprises also a high-pressure feeder ( 8 ) of a conventional type, which makes impregnation possible in an unpressurised impregnation vessel. A high-pressure feeder is a sluice feed that is equipped with a rotor having pockets that pass symmetrically through it, and that through rotation are placed alternately in connection with a low-pressure and a high-pressure system without any communication being allowed between these two systems. The chips are transported from the outlet ( 5 ) on the low-pressure side into one of the pockets of the high-pressure feeder ( 8 ) and, once the pocket has been filled, the rotor rotates a quarter of one rotation such that the pocket arrives on the high-pressure side at a location for emptying where a transport fluid, in this case black liquor ( 14 ), expels the chips from the pocket for transport onwards towards the top ( 3 ) of the digester. The chips can, in this way, be carried from a system at zero pressure or at low pressure, typically 0-4 bar (abs) and they can be fed via the high-pressure feeder into a system with considerably higher pressure, typically 7-20 bar (abs).
[0018] A digester ( 2 ) of steanlfluid phase type is shown in FIGS. 1 and 2 with a top separator ( 7 ) at the top, according to ( 7 a ) in FIG. 3 b, but the invention can also be applied in a hydraulic digester system with a separation of chips and transport fluid in a strainer section in the top of the digester, according to ( 7 b ) in FIG. 4 b. Those circulations that are not relevant to the invention, circulations of impregnation fluid and cooking fluid for the establishment of the correct fluid/wood ratio, alkali and temperature adjustments and withdrawal of fluid for the recovery of chemicals, are not shown in FIGS. 1 and 2, but it is to be understood that the invention can be applied in all types of digester system, such as, for example, MCC, EMCC, ITC, Lo-Solids, etc. Thus, both the impregnation vessel and the digester can be equipped with several circulations and withdrawals for process fluid in order to achieve different conditions, depending on the raw materials and the desired quality of the final cooked pulp, something that has been partially made clear in FIGS. 3 a and 4 a. For example, white liquor can be added in batches at the feed, at the impregnation vessel, or at the top zone, central zone or bottom zone of the digester. Impregnation vessels and digesters may be equipped both with zones of concurrent flow and countercurrent flow with withdrawal points for black liquor, and withdrawal of black liquor for recovery of chemicals can take place at several locations, such as, for example, from the impregnation vessel, from the return line of the transport fluid, or from the digester. These circulations and withdrawals can take place via conventional strainer sections, and they can also be constituted by strainer-less withdrawals that only consist of connection pieces (i.e. pipes) mounted in release positions in the walls of the vessel.
[0019] The invention will now be described in more detail based on FIGS. 1 and 2. What characterises the invention is the lack of a conventional transfer circulation between the. outlet ( 5 ) of the impregnation vessel and the inlet ( 3 ) of the digester to the extent that transport fluid ( 10 ) after separation from the chips in the separation equipment ( 7 ) at the top of the digester is not recirculated to the outlet ( 5 ) of the impregnation vessel. Hot black liquor ( 14 ) is, instead, used to transport the impregnated chips typically at a temperature in excess of 140° C., from one of the black liquor withdrawal points that is led to a final concurrent mixing zone (Z 2 ) in the impregnation vessel ( 1 ) and/or to the inlet ( 13 ) for transport fluid in the high-pressure feeder ( 8 ), in order there to be mixed into a chips mixture consisting of the impregnated chips and the accompanying impregnation fluid. The mixing zone (Z) and the high-pressure feeder ( 8 ) both constitute the beginning of a transfer system ( 4 ), a more accurate definition of which is given later. According to the invention, at least 25% and preferably 50% of the total amount of black liquor ( 14 ) that is withdrawn from the digester is to be led back in order in this way to be mixed with the chips mixture. The temperature of the chips mixture will in this way be raised during transport in the transfer system ( 4 ) and sufficient black liquor ( 14 ) is used in one preferred embodiment that no further heating is required. This will be the case when the temperature of the chips mixture is raised by between 5-25° C. as a consequence of the addition of black liquor. The withdrawn black liquor ( 14 ) has a temperature of T av which is essentially to be maintained until the black liquor is added in the transfer system. This means that no forced cooling via flashing, heat exchange or similar measures is carried out in order to cool the black liquor. The only cooling that may arise is that which naturally arises as heat loss from the tubes in which the black liquor is transported. A heating of the chips mixture normally takes place in a conventional transfer circulation by the transport fluid ( 10 ) being heated in a heat exchanger ( 9 ), see FIGS. 3 and 4, before it is returned to the outlet ( 5 ) of the impregnation vessel.
[0020] Part of the transport fluid ( 10 ) is separated from the chips mixture in separation equipment ( 7 ) at the inlet ( 3 ) of the digester, see FIGS. 3 b and 4 b for more detail. The is hot transport fluid ( 10 ) is subsequently led fully or partially back to the impregnation vessel ( 1 ) and is added in a first zone (Z,) before the final concurrent flow mixing zone (Z 2 ) in order in this way to constitute part of the impregnation fluid in this first zone (Z 1 ). The transport fluid ( 10 ) can be added at one or several locations in this first zone (Z 1 ) and the impregnation can take place under concurrent flow, countercurrent flow or both, depending on how the digester system is operated. It is desirable, in order to obtain a heating effect according to the invention, that the transport fluid ( 10 ) is allowed a retention time corresponding to 40% and preferably at least 50% of the total retention time t imp of the chips in the impregnation vessel ( 1 ). According to the innovative concept, an impregnation with black liquor is obtained at a lower temperature with this method than that obtained when the black liquor is led directly from the digester to the impregnation vessel. At the same time, the temperature in the transfer system is raised, which results in the heat exchanger that is normally required for heating in the transport circulation can be eliminated or reduced in size. As has been indicated in FIG. 2 (and as also applies to FIG. 1), a certain cooling of the transport fluid ( 10 ) that has been added to the impregnation vessel ( 1 ) at one location, preferably the upper location, can take place, in order to obtain in this way a successive heating of the chips during impregnation.
[0021] Black liquor is here used to denote cooking fluid that has been drawn from the digester ( 2 ) after a bulk delignification that is equivalent to at least 40% of the total bulk delignification has taken place, or after at least 50% of the total reduction in kappa value has taken place. However, the withdrawal must take place after a minimum of 30 minutes of cooking, in order for the fluid to be characterised as black liquor. One skilled in the arts will realise that the location of the withdrawal will vary depending on the particular method of cooking and the cooking conditions that are associated with the method, and can thus be constituted by a withdrawal at the beginning, the centre or the end of the digester in a concurrent flow zone or a countercurrent flow zone or as a withdrawal between an upper concurrent flow zone and a subsequent countercurrent flow zone. It is also possible to use more than one withdrawal. The transfer system ( 4 ) comprises, when considered in the direction of flow of the chips:
[0022] a final concurrent flow mixing zone (Z 2 ) in the impregnation vessel ( 1 ) with a retention time (t 2 ) for the chips in this mixing zone that constitutes a maximum of 25% of the retention time, timp, of the chips in the impregnation vessel such that t 2 <0.25 t imp ,
[0023] the outlet ( 5 ) of the impregnation vessel,
[0024] a transfer line ( 6 ) between the outlet ( 5 ) of the impregnation vessel and the inlet ( 3 ) of the digester, possibly also comprising a high-pressure feeder ( 8 ), see FIG. 2, at a location after the outlet ( 5 ) of the impregnation vessel,
[0025] and separation equipment ( 7 ) located in direct contact with the inlet ( 3 ) of the digester, or immediately underneath it, in order to separate transport fluid ( 10 ) from the chips mixture.
[0026] This separation equipment ( 7 ) in a steam/fluid phase digester consists of what is known as a top separator ( 7 a ), according to FIG. 3 b, while in a hydraulic digester it consists of a strainer section ( 7 b ), according to FIG. 4 b.
[0027] The beginning of the transfer system is here taken to denote in accordance with the above definition a final concurrent flow zone (Z 2 ) in the impregnation vessel ( 1 ), the outlet ( 5 ) of the impregnation vessel and the high-pressure feeder ( 8 ), if present.
[0028] [0028]FIG. 3 a shows schematically a conventional two-vessel steam/fluid phase digester and FIG. 3 b shows in more detail what is known as an upward-feed or inverted top separator ( 7 a ) in which chips and transport fluid are fed into the lower end of the top separator. The chips are fed upwards under the influence of the feed-screw ( 11 ) over the edge of the top separator and thus fall down into the digester. A fraction of the transport fluid ( 10 ) is withdrawn through the strainer ( 12 ) that surrounds the screw.
[0029] [0029]FIG. 4 a shows schematically a two-vessel hydraulic digester and FIG. 4 b shows in more detail the strainer section ( 7 b ) for separation of the chips and transport fluid ( 10 ) at the top of the digester.
[0030] The invention can be modified in several ways within the framework of the claims. The black liquor 14 from the black liquor withdrawal that is added to the transfer system can thus be added only at one of the three locations shown, or at combinations of two of these.
[0031] Furthermore, a shunt line ( 20 ) can also be used, for example during the start of the process, when the digester is filled with the impregnated chips and before black liquor of the correct temperature and with the correct level of residual alkali content has been established. This shunt line may then be closed once operation has been established. Depending on where black liquor is withdrawn for recovery of chemicals, and on other factors, this shunt line can also be used to-establish different ratios of fluid to wood in the impregnation vessel, the transfer system or the digester, and the fluid flow can thus pass in both directions in this line, depending on the method of operation of the system.
|
A method for the continuous cooling of chemical pulp with the aim of achieving improved heat economy in a digester system comprising a vessel ( 1 ) for impregnation and a vessel ( 2 ) for cooking the impregnated cellulose chips. A part of the black liquor ( 14 ) withdrawn from the digester ( 2 ) is added at the beginning of a transfer system ( 4 ) having maintained essentially the withdrawl temperature, increasing the temperature of the chips mixture in the transfer system ( 4 ). A fraction of the transport fluid ( 10 ) from the transfer system ( 4 ) that is continuously withdrawn from the impregnated chips fed into the top of the digester is returned to the impregnation vessel ( 1 ) at essentially maintained transfer temperature, at a location before the said transfer system ( 4 ), seen from the point of view of the direction of flow of the chips.
| 3
|
This is a divisional of co-pending application Ser. No. 652,869 filed on Sept. 20, 1984 now abandoned. which is a continuation-in-part of U.S. patent application Ser. No. 592,945 entitled CLEANING SYSTEM filed Mar. 23, 1984, now U.S. Pat. No. 4,640,638 the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to a cleaning system utilizing a cleaning fluid capsule, particularly for use in cleaning bathrooms and bathroom plumbing fixtures.
DESCRIPTION OF THE PRIOR ART
Typically bathroom fixtures, such as conventional commodes, or water closets, found in the home, or wall-mounted urinals found in such places as commercial building bathrooms, are cleaned with a short handled brush or sponge and a conventional scouring powder contained in a can or with a liquid cleaner which is poured or sprayed from a bottle. Suffice to state that cleaning such plumbing fixtures with the foregoing described brush is an arduous and awkward task.
One attempt to alleviate the inherent problems encountered in cleaning bathroom fixtures is disclosed in U.S. Pat. No. 4,217,671, issued to Rand on Aug. 19, 1980. This patent discloses an electrically powered cleaning device wherein a plurality of different shaped scrubber heads are rotated by an electrical motor, and a gravity operated detergent dispenser is associated with the device. The apparent disadvantages with this cleaning device are that may restrooms may not have an electrical outlet conveniently located with respect to the commode, or water closet, to be cleaned; as well as the inherent, potential danger associated from operating an electrical device, a portion of which is immersed in water. Another apparent disadvantage would be that the weight of such a device could easily cause muscle strain for the worker utilizing such a device to clean commodes, or water closets, and/or wall mounted urinals. A further apparent disadvantage of this device would appear to be the expense of manufacturing such a device, particularly when an electrical motor must be included therewith. Additionaly there would appear to be another safety hazard in that a strong possibility would exist that detergent could drop onto the rotating brush and be flung into an operator's eye, or alternatively, such material could riccochet from the rotating brush to the bathroom fixture into the operator's eye.
Accordingly, prior to the development of the present invention, there has been no cleaning device or system particularly adapted for cleaning bathroom plumbing fixtures which is simple and economical to manufacture, safe to operate and use, and prevents muscle strain to the operator of the system. Therefore, the art has sought a cleaning system for bathroom plumbing fixtures which is simple and economical to manufacture, is easily and safely used and seeks to eliminate muscle strain and other inherent problems encountered when cleaning bathroom plumbing fixtures.
SUMMARY OF THE INVENTION
In accordance with the invention the foregoing advantages have been achieved through the present cleaning system. The present invention includes an elongate handle having first and second ends and a cleaning fluid cartridge means adapted to contain a cleaning fluid; the handle includes a surface cleaning means disposed at the first end, the cleaning fluid cartridge means being disposed at the second end, a means for pumping the cleaning fluid from the fluid cartridge means to the surface cleaning means, said pump means being associated with the cleaning fluid cartridge means, and a pump actuation means associated with the pump means and the handle. A feature of the present invention is that the cleaning fluid cartridge means may be removably attached to the handle. A further feature of the present invention is that the surface cleaning means may be a mop head disposed on the first end of the handle, the mop head including a fluid passageway to allow the cleaning fluid to be pumped through, and outwardly of, the mop head to a surface to be cleaned.
An additional feature of the present invention is that the handle may include means for supporting the fluid cartridge means, including a housing associated with the handle and the housing has a movable door allowing access to the interior of the housing. Another feature of the present invention is that a safety switch means may be associated with the handle, which safety switch means has:a first loading position wherein the pump actuation means is not operable and the housing door is movable to allow the cleaning fluid cartridge means to be inserted within the housing; a second locked position wherein the pump actuation means is not operable and the housing door is not movable; and a third operating position wherein the pump actuation means is operable and the housing door is not movable.
Further, in accordance with the present invention, the pump means may comprise a pump chamber defined by an upper wall and a flexible side wall interconnecting the upper wall to the cleaning fluid cartridge means, with a fluid passageway having first and second ends passing through the pump chamber in fluid communication between the cleaning fluid cartridge means and the handle, whereby upon movement of the pump actuation means, cleaning fluid is pumped from the cleaning fluid cartridge means into the handle. An additional feature of the present invention is that the pump means may comprise a pump chamber defined by upper and lower end walls and a flexible side wall interconnecting the upper and lower end walls, wherein a fluid passageway having first and second ends passes through the pump chamber in fluid communication between the cleaning fluid cartridge means and the handle, whereby upon movement of the pump actuation means, cleaning fluid is pumped from the cleaning fluid cartridge means into the handle. The foregoing upper and lower end walls of the pump chamber, in accordance with the present invention, may each comprise an annular disk having an outer diameter and an inner diameter; each annular disk having a truncated cone configuration wherein one disk tapers upwardly and one disk tapers downwardly at an acute angle from the outer diameter to the inner diameter.
A further feature of the present invention is that the cleaning system may further include a means for maintaining pumping of cleaning fluid from the cleaning fluid cartridge means after activation of the pump actuation means. The means for maintaining pumping, in accordance with the present invention, may include a flexible and expandable pump chamber, which is expanded upon operation of the pump actuation means, and a biased support structure cooperating with the pump chamber, which structure is biased against the force exerted upon the pump chamber by the pump actuation means, whereby after the pump actuation means has expanded the pump chamber and applied a force thereto, the biased support structure exerts a force upon the pump chamber to maintain the pumping of cleaning fluid from the cleaning fluid cartridge means.
The present invention thus provides a cleaning system utilizing a hollow bodied, disposable dispensing capsule or package comprising a storage chamber and dispensing chamber in a one piece, hollow, blow molded container made of an elastic, resilient, synthetic plastic material. The package is connected to the system handle via a conical protrusion on the package closure. An orifice separating the two chambers is provided with a movable, inlet clapper valve, the dispensing chamber outlet orifice being normally closed by a spring urged valve. Deformation of the elastic walls of the bellows shaped dispensing chamber dispenses a discrete amount of liquid to the system handle without relying on qravity. Compression of the dispensing chamber reduced the volume thereof, closes the inlet clapper valve, and opens the outlet valve to dispense the product. The conically shaped storage chamber provides for ready pumping and evacuation of cleaning fluid therefrom, the flexible walls collapsing inward as a result of the vacuum created by the decompression of the dispensing chamber.
The cleaning system of the present invention, when compared with previously proposed prior art cleaning devices has the advantages of being simple and economical to manufacture and use, is safe to manufacture and use (when properly used), and helps to prevent and/or alleviate muscle strain associated with the cleaning of bathroom plumping fixtures, and other surfaces which need to be cleaned.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B present a partial cross sectional view along the longitudinal axis of a cleaning system in accordance with the present invention; FIG. 1B being broken off from FIG. 1A as shown by dotted lines.
FIG. 2 is a cross sectional view of a cleaning fluid cartridge means in accordance with the present invention.
FIG. 2A and 2B are cross sectional views of the cleaning fluid capsule illustrating fluid flow through the cartridge, valves, and pump.
FIG. 3 is a partial front view of a portion of the cleaning system of the present invention taken along line 3--3 of FIG. 4.
FIG. 4 is a side view of the end cap member utilized in the present invention.
FIG. 5-A, 5-B and 5-C are partial cross sectional views illustrating the sequential operation of the pump means and means for maintaining pumping of cleaning fluid in accordance with the present invention.
While the invention will be described in connection with the preferred embodiment, 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 THE PREFERRED EMBODIMENT
In FIGS. 1-A and 1-B, a cleaning system 60, in accordance with the present invention, is shown to generally comprise an elongate handle 61 having first and second ends, 62 and 63, and a cleaning fluid cartridge means 64 disposed at the second end 63 and adapted to contain a cleaning fluid, as will be hereinafter described. Handle 61 preferably includes a surface cleaning means 65 disposed at the first end 62 of handle 61, which surface cleaning means 65 will be hereinafter described in greater detail. Handle 61 further preferably includes a means for pumping 66 the cleaning fluid from the cleaning fluid cartridge means 64 to the surface cleaning means 65; and the pump means 66 is preferably associated with the cleaning fluid cartridge means 64, as will be hereinafter described in greater detail. Further, handle 61 preferably includes a pump actuation means 67 associated with the pump means 66 and handle 61.
Still with reference to FIGS. 1-A and 1-B, the cleaning fluid cartridge means 64 is preferably removably attached to handle 61, as will be hereinafter described in greater detail. Handle 61 may further include means for supporting 68 the fluid cartridge means 64, which means for supporting 68 preferably includes a housing 69 associated with handle 61. Housing 69 preferably has a movable door 70 which allows access to the interior of housing 69. Door 70 is illustrated in FIG. 1-A in its closed position in solid lines, and is illustrated in its open position as illustrated by the dotted lines. Door 70 may be pivotably or hingedly attached to housing 69 as at pivot or hinge point 71, in any suitable manner. Handle 61 could terminate at the point shown in FIG. 1-A by dotted lines 72, whereby the fluid cartridge means 64, including pump means 66, could be removably attached to the handle 61 and supported by the handle 61 and cleaning fluid cartridge means 64 would be exposed. Preferably support means 68 would then comprise the portion of handle 61 disposed between dotted lines 72 and 73, including support walls 74 which will be hereinafter described in greater detail. Preferably, in order to provide for greater support of the cleaning fluid cartridge means 64 and to protect it from damage, support means 68 is comprised of housing 69 which extends from the bottom 75 of housing 69 to the handle 61 at dotted lines 73, and the upper wall 76 of housing 69 is formed integral with handle 61. Preferably, handle 61, housing 69, pump actuation means 67, and/or door 70, are all formed of a suitable plastic material having the requisite strength and corrosion resistant characteristics to withstand the forces exerted upon the cleaning system 60 when used, as well as withstand contact with the cleaning fluid (not shown) utilized in cleaning fluid cartridge means 64. In this regard, any suitable cleaning fluid could be utilized; however, in the case of cleaning bathroom fixtures, it would be desirable to utilize an acid solutaion as the cleaning fluid.
Still with reference to FIGS. 1-A and 1-B, it is seen that surface cleaning means 65 may comprise a mop head 77 disposed on the first end 62 of handle 61. Mop head 77 could be of any configuration, and made of any material having the requisite properties for rubbing, or scrubbing, against a surface to be cleaned, and having the requisite corrosion resistance properties against deterioration from contact with the cleaning fluid utilized in the cleaning system 60. Alternatively, a suitable brush could be substituted for mop head 77, and it should be understood that the term mop head 77 or surface cleaning means 65, encompasses any structure suitable for scrubbing, or rubbing, against a surface to be cleaned. Mop head 77 can be provided with a backing structure 78 which may be permanently or removably affixed to the first end 62 of handle 61 as by a press-fit or snap connection as shown at 79, via an annular ring 80 which presses backing structure 78 about the first end 62 of handle 61.
Still with reference to FIGS. 1-A and 1-B it is seen that handle 61 includes a first fluid passageway 81, having first and second ends 82, 83 in fluid communication between the cleaning fluid cartridge means 64 and the first end 62 of handle 61. Fluid passageway 81 may be comprised of a length of tubing of any suitable material compatible with the cleaning fluid. As will be hereinafter described in greater detail, upon operation of pump actuation means 67, cleaning fluid is pumped from cleaning fluid cartridge means 64 via pump means 66 into the first fluid passageway 81. Mop head 77, including its backing structure 78 may be provided with a second fluid passageway 84, or as shown in dotted lines, 84'. Fluid passageways 84 and 84' are in fluid communication with the first fluid passageway 81, whereby cleaning fluid may be pumped through the mop head 77 via second fluid passageway 84 and out of mop head 77. Alternatively, the cleaning fluid may be pumped from first fluid passageway 81 into the second flurd passageway 84' and pumped outwardly thereof to the surface (not shown) which is desired to be cleaned.
With reference to FIG. 1-B, it is seen that a safety means 85 for preventing cleaning fluid from draining from the first fluid passageway 81 is associated with the first end 62 of handle 61. Preferably, safety means 85 comprises a safety check valve 86 disposed proximate the first end 62 of handle 61. Safety check valve 85 may be biased into a first position, as shown in FIG. 1-B to seal the first end 82 of the first fluid passageway 81, which is adjacent the safety check valve 86, in which position the safety check valve 86 prevents transmission of cleaning fluid outwardly of handle 61. Safety check valve 86 further prevents cleaning fluid from draining outwardly of the second end 83 of the first fluid passageway 81, which is disposed proximate the second end 63 of handle 61. Thus, were cleaning fluid cartridge means 64 to be removed from handle 61, the sealing of the first end 82 of fluid passageway 81, in conjunction with surface tension and/or capillary action associated with the cleaning fluid disposed in first fluid passageway 81, would prevent the cleaning fluid from draining from the second end 83 of the first fluid passageway. It should be noted that safety check valve 86 is preferably spring loaded. A plastic helical spring 87 may bias a sealing disk 88, via shaft member 89 affixed to sealing disk 88, against the first end 62 of handle 61. The safety check valve 86 is movable to a second open position to allow cleaning fluid to be pumped outwardly of the safety check valve 86 upon the cleaning fluid being pumped through the first fluid passageway 81. Thus, upon the fluid pressure of the cleaning fluid disposed within first fluid passageway 81 exceeding the biasing force of the spring 87 of safety check valve 86, sealing disk 88 moves in a direction toward the mop head 77 to allow the cleaning fluid to pass into either second fluid passageway 84 or 84'.
With reference to FIG. 1-A, it is been that handle 61 may be provided with a safety switch means 90, which has a first locked position wherein the pump actuation means 67 is not operable and a second operating position wherein the pump actuation means 67 may be operated. In this regard, pump actuation means 67 may comprise a movable member, or trigger member 91 disposed within a slotted opening 92 in handle 61, which is operatively engageable with pump means 66 to exert a force upon pump means 66. Preferably, trigger member 91 is operatively engageable with the pump means 66 via a movable linkage 93 to exert a force upon the pump means 66, as will be hereinafter described in greater detail. Trigger member 91 may be pivoted about pivot point 94 disposed within handle 61, and may have a curved lower surface 95 which may be engaged by a human operator grasping handle 61 with at least one finger against surface 95, whereby trigger member 91 may be depressed and pivoted about pivot point 94 in the direction shown by arrow 96.
Still with reference to FIG. 1-A, it is seen that safety switch means 90 may include a button, or switch, member 97 affixed to an elongate engagement member 98. Button member 97 is disposed within a slot 99 formed in handle 61, and is retained within slot 99 in any suitable manner, such as by pins 100 which engage the underside of elongate engagement member 98 to secure engagement member 98 between pins 100 and the interior of housing 61. Safety switch means 90 may further have a first loading position wherein the pump actuation means 67 is not operable and the housing door is movable to allow the cleaning fluid cartridge means 64 to be inserted within the housing, upon door 70 being opened. A second locked position is provided by safety switch means 90 wherein the pump actuation means 67 is not operable and the housing door 70 is not movable. Further, safety switch means 90 may be provided with a third operating position wherein the pump actuation means 67 is operable and the housing door 70 is not movable, whereby trigger means 91 may be depressed, but door 70 may not be opened while cleaning system 60 is being utilized with trigger member 91 being depressed. As shown in FIG. 1-A in solid lines, the elongate engagement member 98 of safety switch means 90 is shown disposed in the second locked position wherein the pump actuation means 67, or trigger member 91, is not operable and the housing door is not movable. This second locked position corresponds to switch 97 being disposed within the center of slot 99 as illustrated in FIG. 1-A. It should be noted that end 101 of elongate engagement member 98 is disposed over a notch 102 formed in trigger member 91, whereby upon exerting a force on trigger member 91 in the direction shown by arrow 96, notch 102 would abut against end 101 of elongate engagement member 98. The other end 103 of elongate engagement member 98 is shown disposed in an abutting relationship with a stop member 104 provided to door 70 of housing 69. Were an operator to attempt to pivot door 70 downwardly in the direction shown by arrow 105, the end 103 of elongate engagement member 98 would abut against stop means 104, whereby the door could not be opened.
Still with reference to FIG. 1-A, the previously described first loading position of safety switch means 90 would correspond to movement of button, or switch, member 97 to its furthermost position within slot 99 toward trigger member 91, as shown by dotted lines 106. In this first loading position, movement of trigger 91 would once again be prevented by the abutment of notch 102 against end 101 of elongate engagement member 98. The movement of elongate engagement member 98 into the first loading position would cause end 103 of elongate engagement member 98 to move away from stop means 104, whereby the door 70 could be swung open to allow a cleaning fluid cartridge means 64 to either be unloaded from housing 69, or to allow a new cleaning fluid cartridge means 64 to be inserted within housing 69.
When the button member 97 of safety switch means 90 is moved to its furthermost position within slot 99 toward the housing 69, the end 101 of elongate engagement member 98 would not abut against notch 102 in trigger member 91, whereby trigger member 91 could be depressed. In this operating position, end 103 of elongate engagement member 98 would be in a complete abutting relationship with stop means 104 as shown by dotted lines 107. Thus, while cleaning system 61 is utilized and trigger member 91 is being depressed, an operator would not be able to gain access to the interior of housing 69.
The advantages of having a safety switch means 90, such as the three position slide switch of button, or switch, member 97 and elongate engagement member 98, provides important safety factors, particularly when the cleaning fluid utilized in cleaning fluid cartridge means 64 is an acid type solution. When an operator is either loading or unloading a cleaning fluid cartridge means 64, the pump means 66 cannot be actuated in that movement of trigger member 91 is restrained, thus preventing accidental discharge of cleaning fluid, as described in connection with the first loading position. When cleaning system 61 has the safety switch means 90 disposed in the second locked position, previously described, an operator may safely carry the cleaning system 61 and accidental movement of trigger member 91 is precluded. Accidental opening of door 70 is likewise prevented, which could result in the cleaning fluid cartridge means 64 falling from housing 69 and possibly splashing on the floor or the operator. Cleaning fluid can only be pumped from the cleaning system 60 when the safety switch means 90 is disposed in the third operating position, at which time accidental opening of door 70 is precluded, as well as movement of cleaning fluid cartridge means 64 from housing 69 is likewise precluded.
Still with reference to FIG. 1-A, trigger member 91 preferably has a first operating position wherein a force sufficient to actuate the pump means 66 is generated and transmitted to the pump means 66, shown as dashed lines 91a; a second non-operating position wherein a pre-load force not sufficient to actuate the pump means 66 is generated and transmitted to the pump means 66; and a third non-operating position wherein the pre-load force is relieved to allow a cleaning fluid cartridge means to be disposed at the second end of handle 61, shown as dashed lines 91b. The first operating position of trigger member 91 corresponds to when trigger member 91 has been depressed in the direction shown by arrow 96 whereby movable linkage 93 has exerted a force upon pump means 66. In this regard, and further with reference to FIGS. 3 and 4, it is seen that movable linkage 93 may comprise a pivotable swing arm 110 and an end cap member 111, as seen in FIGS. 3 and 4. Swing arm 110 and end cap member 111 have a common pivot point, or shaft, 112, and swing arm 110 is in turn pivoted about shaft 113 associated with housing 61. Swing arm 110 has a camming surface 114 which is in sliding engagement with surfaces 115 of trigger member 91, whereby upon movement of trigger member 91 in the direction shown by arrow 96, camming surface 114 slides on surfaces 115 and swing arm 110 pivots about shaft 113. This in turn causes movement of end cap member 111 in the direction shown by arrow 116 as end cap member 111 pivots about shaft 113. As the trigger member 91 is depressed, tip 117 of camming surface 114 of swing arm 110 will engage notch 102 in trigger member 91 and thus will reach the end of its travel. Preferably, swing arm 110 is comprised of two spaced plate members having the configuration shown in FIG. 1-A, whereby first fluid passageway 81 may pass through the space between the two plate members and not interfere with the movement of swing arm 110.
Still with reference to FIGS. 1-A and FIGS; 3-4, it is seen that the interior of handle 61 may be provided with two sets of spaced track members 118, 119, the track members 118 and 119 appearing in dotted lines in FIG. 3. The movement of end cap member 111 in the direction shown by arrow 116 is thus obtained by the sliding engagement of a plurality of guide members 120 mounted on end cap member 111, being restrained by the track members 118 and end cap member 111 riding along or on track members 119. End cap member 111 may further be provided with a nozzle receiveng cavity and pressure transmitting member 121 which engages the pump means 66 of cleaning fluid cartridge means 64 as will be hereinafter described. End cap member 111 further includes a means for receiving 122 the second end 83 of the first fluid passageway 81. Preferably, receiving means 122 is an annular shaped cavity in which the second end 83 of tubing 81 is fixedly secured, and the annular shaped cavity 123 is in fluid communication with the nozzle receiving cavity 121 as by a passageway 124.
Referring now to FIG. 1-A, it should be noted that trigger member 91 is illustrated in the second non-operating position wherein a pre-load force not sufficient to actuate the pump means 66 is generated and transmitted to the pump means 66 via movable linkage 93. As shown in FIG. 1-A, trigger member 91 is provided with a means for releasably maintaining 125 the trigger member 91 in the second non-operating position. The means for releasably maintaining trigger member 91 in this position may comprise two spaced, flexible arms 126 each having an outwardly extending lip 127 which extends outwardly and overlies a rail member 128. Lips 127 may each have a bevelled surface 127A underneath, as will be hereinafter described. In this regard, two spaced rail members 128 are provided, and they may be integral extensions of the track members 119 previously described. Upon abutment of lip members 127 with the rail members 128, downward movement of trigger member 91 is selectively precluded. However, when lip members 127 engage and abut against rail members 128, trigger member 91 is still causing movement of end cap member 111 to a limited degree via the abutment of cam surface 114 of swing arm 110 against surface 115 of trigger member 91. This force, or pre-load force, resulting from the movement of end cap member 111 against pump means 66 is not enough force to actuate the pump means 66, but assists the trigger member 91 to reassume its second nonoperating position after the actuation of pump means 66. When trigger member 91 has reached the limit of its upward travel in the direction shown by arrow 96, trigger member 91 is in its first operating position previously described.
Still with reference to FIG. 1-A, upon grasping trigger member 91 and pulling it downwardly with a sufficient force, the flexible arms 126 are forced inwardly by the sliding engagement of bevelled surfaces 127A of lip members 127 against the tops of rail members 128. Releasable maintaining means 129, for maintaining the trigger member 91 in its third non-operating position may preferably comprise a pair of spaced arm members 130 having outwardly engageable lip members 131 which abut against rail members 128 to prevent trigger member 91 from being pulled completely downwardly out of handle 61. When trigger member 91 has been pulled downwardly until lip members 131 engage rail members 128, the camming surface 114 of swing arm 110 likewise moves downwardly and causes longitudinal movement of end cap member 111 away from pump means 66 to thus allow either a cleaning fluid cartridge means 64, including pump means 66, to be inserted or removed from housing 69. After a new cleaning fluid cartridge means 64 has been inserted within housing 69, trigger member 91 is pushed upwardly in the direction shown by arrow 96 until arm members 126 spring outwardly whereby lip members 127 once again engage rail members 128. Further upward movement of trigger member 91 is precluded by the abutment of notch 102 of trigger member 91 against the elongate engagement member as previously described. It should be noted that pump actuation means 67, including linkage 93 and safety switch 90, could be manufactured as a single unit and then press-fitted into handle 61.
Turning now to FIG. 2, FIG. 2A, and FIG. 2B, the cleaning fluid cartridge means 64 and pump means 66 of the present invention will be described in greater detail. Pump means 66 may comprise a pump chamber 135 defined by an upper wall 136 and a flexible side wall 137 interconnecting the upper wall 136 to the cleaning fluid cartridge means 64. A fluid passageway 138 having first and second ends 139, 140 passes through the pump chamber 135 in fluid communication between the cleaning fluid cartridge means 64 and to the handle 61, or nozzle receiving cavity 121 of end cap member 111, as shown in FIG. 1-A. Upon movement of the pump actuation means, or trigger member 91, cleaning fluid is pumped from the cleaning fluid cartridge means 64 into the handle 61 as will be hereinafter described in greater detail. Preferably, pump chamber 135 further includes a lower end wall 141, with flexible side wall 137 disposed between upper and lower walls 136, 141. It should be noted that if lower end wall 141 is not utilized, flexible side wall 137 could be extended, as shown by dotted lines 142 in FIG. 2, to connect to the fluid cartridge means 64. Pump means 66 further comprises a stiff flange 66a to connect nozzle member 160 thereto and a stiff support flange or pump support 66b.
Still with reference to FIG. 2, the upper and lower end walls 136, 141 of pump chamber 135, preferably each comprise an annular disk 143 having an outer diameter 144 and an inner diameter 145. Each annular disk 143 is in a configuration generally described as a truncated cone configuration, wherein each disk 143 tapers upwardly or downwardly at an acute angle from the outer diameter 144 to the inner diameter 145. Preferably, the angle θ falls within a range of from 10° to 35°, with angles of from 15° to 28° being particularly preferred. The outer diameter of each annular disk 143 is joined to the flexible side wall 137, and as shown in FIG. 2, the inner diameter 145 of one of the annular disks 143 is joined to the cleaning fluid cartridge means 64. If the pump chamber is only comprised of the upper wall 136 and the flexible side wall 137, the outer diameter 144 of upper wall 136 is joined to flexible side wall 137, and the lower end of flexible side wall 137 is joined to the cleaning fluid cartridge means 64. Pump means 66 is thus a unique type of bellows comprising two Belville washers (143) and an integral connecting band (137).
Further, as shown in FIG. 2, FIG. 2A, and FIG. 2B, valve means 146, 147 are disposed in the inner diameter of each annular disk 143, within passages 139 and 140, respectively, and preferably each valve means 146, 147 comprises a check valve. Preferably, valve means 146 is a spring-biased check valve 148, having a sealing member, or sealing disk, 149 biased downwardly toward pump chamber 135, as by a spring member 150 having an integral flange member 150a connected in a snap fit to a shoulder of nozzle member 160. Spring member 150 exerts a biasing force upon a shaft member 151 integral with the sealing disk 149 due to the engagement of spring 150 within groove 151a of shaft 151, as illustrated in FIGS. 2A and 2B, and shaft 151 may also be secured to the end of the spring member 150 as at 152, as shown in FIG. 2. This valve means 146 is similar in construction to the safety check valve 86 described in connection with FIG. 1-B. Check valve 147 may preferably be a clapper check valve 153 which is freely movable within the inner diameter 145 of the annular disk 143 of lower end wall 141. Clapper check valve 153 may have a plurality of wedge members 154 disposed about its outer surface which prevent clapper check valve 153 from passing upwardly into pump chamber 135. Clapper check valve 153 is also provided with a tapered sealing surface 155 disposed about its outer upper circumference, in that clapper check valve 153 has a generally circular cross sectional configuration when viewed from the top of the pump chamber 135. Sealing surface 155 also serves to prevent clapper check valve 153 from falling into cleaning fluid cartrdige means 64. The travel of valve 153 within diameter 145 is thus limited to a distance "D", as illustrated in FIG. 2A. It should be noted that were lower end wall 141 not to be utilized as previously described, an equivalent chamber as shown in FIG. 2 formed by the inner diameter 145 of lower end wall 141 would be provided to cleaning fluid cartridge means 64 in order for clapper valve 153 to properly operate. It should also be noted that different types of check valves could be utilized for valve means 146, 147 as long as the desired sealing effect is provided for the pump chamber 135, as will be hereinafter described in greater detail. It should further be noted that pump means 66, and its pump chamber 135 are preferably formed integrally with cleaning fluid cartridge means 64; however, it should be apparent to one of ordinary skill in the art that a connection, such as a threaded connection, could be provided between pump chamber 135 and cleaning fluid cartridge means 64 to enable the pump means 66, or pump chamber 135, to be removably secured to the cleaning fluid cartridge means 64.
Pump means 66 is further provided with a nozzle member 160, of any suitable shape, which nozzle member mates with the nozzle receiving cavity 121 of end cap member 111, as previously described in connection with FIGS. 1-A and 4. When the pump means 66 is formed as an integral component with the cleaning fluid cartridge means 64, nozzle member 160 may be provided with a closure tip 161 which is removably mounted to nozzle member 160 as by a frangible connection at 162, whereby closure tip 161 remains on the pump means 66 and cleaning fluid cartridge means 64 while it is being stored. When it is desired to insert the cleaning fluid cartridge means 64 and pump means 66 into the cleaning system 60, the closure tip 161 is removed from nozzle member 160. Preferably, all of the components of the cleaning fluid cartridge means 64 and pump means 66, previously described, are manufactured of a suitable plastic material; however, valve means 146, 147 could also be manufactured of a suitable corrosion-resistant metallic material. In the preferred embodiment, however, spring member 150 is plastic to eliminate deterioration of a metal spring member caused by the acidic cleaning solution. Plastic coil spring check valve 146 is thus able to function in an eighteen percent (18%) hydrochloric acid (HCL) solution without deterioration or significant creep.
Still with reference to FIG. 2, FIG. 2A, and FIG. 2B, when check valve 146 is in its open position, as illustrated in FIG. 2A, cleaning fluid from within pump chamber 135 may pass through the fluid passageway 138 from cleaning fluid cartridge means 64 and into nozzle member 160, and then into first fluid passageway 81 disposed within handle 61.
Preferably, the inner diameter 145 of one annular disk 143 is larger than the inner diameter 145 of the other annular disk 143. As shown in FIGS. 2, 2A, and 2B, the inner diameter 145 of the annular disk 143 which is joined to the cleaning fluid cartridge means 64 is smaller than the inner diameter of the annular disk 143 which forms upper end wall 136. If cleaning system 60 is provided with the safety check valve 86 at the first end 62 of handle 61, it is possible to delete check valve 146 disposed in the upper end of pump chamber 135 in that its sealing action is provided by the safety check valve 86, as will be apparent from the description of the operation of pump means 66 as will be hereinafter described in greater detail.
Still with reference to FIGS. 2, 2A, and 2B, the cleaning fluid cartridge means 64 will be described in greater detail. As shown in FIG. 2, cleaning fluid cartridge means is preferably a flexible plastic bottle 165 having a plurality of wall surfaces 166-169 having varying wall thicknesses. For example, wall 166 is thicker than the upper portion of wall 167, whose thickness becomes thinner as wall 167 approaches the intersection between wall 167 and 168. Wall 168 is thinner at its intersection with the lower end of wall 167, and in turn becomes thicker as it approaches its intersection with lower wall 169. Further, wall 169 is thicker than wall 168 and the lower portion of wall 167. It has been found that by varying the wall thicknesses of the walls associated with cleaning fluid cartridge means 64, when cleaning fluid cartridge means 64 is a flexible bottle, satisfactory evacuation of the cleaning fluid contained within bottle 165 is obtained upon successive actuations of pump means 66, in that the various wall surfaces of bottle 165 collapse upon one another due to the pumping out of cleaning fluid from bottle 165 from the suction force created by pump means 66 as will be hereinafter described in greater detail. As seen in FIG. 2, bottle 165 generally has the configuration substantially that of a truncated cone. Alternatively, cleaning fluid cartridge means 64 could be a flexible plastic bag or film pouch which is formed integral with pump means 66, or is secured thereto in any suitable manner, such as by an ultra sonic seal. Further, due to the collapsing of the walls of cleaning fluid cartridge means 64, it should be noted that the pump means 66 will pump fluid when the handle is disposed in any angular orientation, in that the operation of pump means 66 does not rely upon gravity forces for successful operation.
With reference now to FIGS. 2, 2A, 2B, and 5-A, 5-B, 5-C and 1-A, the operation of cleaning system 61 will be described, including a feature of the present invention wherein a means for maintaining the pumping of cleaning fluid from the cleaning fluid cartridge means 64 is obtained after operation of the pump actuation means 67 has ceased movement to apply a force to the pump means 66. With reference to FIGS. 1-A and 5-A, it should be noted that pump support walls 74 are flexibly associated with handle 61, as by flexibly mounting one pump support wall 74 to the interior of housing 69, and flexibly mounting the lower support wall 74 to the interior surface of door 70. Pump support walls 74 may be provided with the requisite flexibility, to be hereinafter described, as by:manufacturing them of a flexible plastic material; joining the support walls 74 along housing 69 and door 70 in a continuous integral connection; having the support walls 74 have a reduced wall thickness at their intersection with capsule 64; or in any other suitable fashion so that the support walls 74 can flex and not be completely rigid. In general, a force is transmitted to the upper end wall 136 of pump chamber 135, as by depressing trigger member 91, which causes longitudinal movement of end cap member 111 upon nozzle 160, which in turn transmits a force to pump chamber 135 in the direction shown by arrow 170 in FIGS. 2 and 2A. The fluid, whether air or cleaning fluid, contained in pump chamber 135 is then compressed. This compression would cause check valve 147 to assume a sealed position within inner diameter 145 of the annular disk 143 which forms lower end wall 141, as illustrated in FIG. 2A. The pressure build-up within pump chamber 135 then causes the spring-biased check valve 146 to open, as further illustrtaed in FIG. 2A, and the fluid contained within pump chamber 135 is pumped through nozzle 160, and into first fluid passageway 81 of handle 61 as previously described, and then out of the first end 62 of handle 61. Upon release of trigger member 91, pump chamber 135 would seek to assume its original configuration as shown in FIG. 2. Check valve 146 would close and a partial vacuum would be created within pump chamber 135 whereby fluid contained in fluid cartridge means 64 would be sucked through check valve 147 into pump chamber 135, as illustrated in FIG. 2B. Successive actuations of trigger member 91 causes all air, if any, in pump chamber 135 and/or cleaning fluid cartridge means 64 to be expelled, whereupon cleaning fluid fills pump chamber 135 and the first fluid passageway 81 up to the safety check valve 86 in handle 61. Thereafter, each time trigger member 91 is depressed, cleaning fluid will be pumped from, or sucked out of, cleaning fluid cartridge means 64.
By utilizing a flexible and expandable pump chamber 135 which is expanded upon operation of the pump actuation means 67, and utilizing a biased support structure 74 which cooperates with the pump chamber 135, cleaning system 60 will continue to pump cleaning fluid from the pump chamber 135 and outwardly of safety check valve 86 after trigger member 91 has been depressed to its maximum upward travel and/or assumed its second non-operating position previously described in connection with FIG. 1-A. It should be noted that the biased support structure 74 biases pump chamber 135 against the force exerted upon the pump chamber 135 by the pump actuation means 67. This means for maintaining the pumping of cleaning fluid from the cleaning fluid cartridge means 64 after operation of the pump actuation means 67 is an important feature of the present invention in that a delayed discharge of cleaning fluid may be provided. In a suitation where an operator of the cleaning system 60 is using the cleaning system 60 to clean a bathroom fixture, or other surface desired to be cleaned, the operator is able to move, or depress, the pump actuation means 67, while at the same time moving the handle in a direction across the surface to be cleaned to spray the cleaning fluid onto the desired surface. In other words, the operator does not have to be constantly actuating the cleaning system 60. For example, the operator could depress trigger means 91 whereby during the depression of trigger member 91, cleaning fluid would be expelled from handle 61 during that step. For approximately one second thereafter, cleaning fluid will continue to be pumped from the cleaning system 60, whereby the operator may merely move the handle 61 to direct the cleaning fluid to the surface to be cleaned. In situations wherein an operator is cleaning a multitude of bathroom fixtures, such as a member of a cleaning staff for a hospital, it is a significant advantage to reduce the number of times the operator must depress the trigger member 91.
With reference to FIGS. 5-A through 5-C, the foregoing means for maintaining the pumping of cleaning fluid from the cleaning fluid cartridge means 64 after operation of the pump actuation means 67 has ceased movement to apply a force to the pump means 66, will be described in greater detail. Throughout FIGS. 5-A through 5-C, pump chamber 135, as previously described in connection with FIGS. 2, 2A, and 2B, including flexible side wall 137 and upper and lower end walls 136, 141 are shown. Further, the flexible pump support walls 74 are also illustrated. The arrow A of FIG. 5-A illustrates the length of flexible and expandable pump chamber 135 at its rest position when disposed in cleaning system 61 with pump actuation means 67, or trigger member 91 being disposed in the position illustrated in FIG. 1-A. Arrow F represents the pre-load force on pump means 66, or pump chamber 135, as previously described. With reference to FIG. 5-B, the configuration of flexible and expandable pump chamber 135 is illustrated after pump chamber 135 has been compressed due to the transmission of the force from the depression of trigger member 91 which is transmitted to pump chamber 135 via swing arm 110, end cap member 111, and nozzle 160, as previously described. The arrow E denotes the pump chamber stroke length due to the force applied by the pump actuation means 67, and the resulting movement of end cap member 111. Letter B denotes the pump length immediately after actuation of pump actuation means 67, or the depression of trigger member 91. Letter G denotes the expansion of pump chamber 135 due to the flexibility of the flexible side wall 137 of pump chamber 135, as well as the flexing of upper and lower end walls 136 and 141 of pump chamber 135. The expansion is caused by the pressure build-up within pump chamber 135 from the fluid contained within pump chamber 135 and initially confined therein by check valves 146 and 147. After valves 146 and 147 are opened, pressure within cartridge 135 is maintained by pressure drop across the exit hole. It should be noted that immediately after actuation of trigger member 91, the force exerted upon pump chamber 135 has caused the flexing, or movement, of the flexible pump chamber support walls 74, and the pump support flex distance is denoted by letter D.
With reference to FIG. 5-C, the arrow C denotes the pump length when delivery of the cleaning fluid has ceased and the trigger member is still depressed. Arrow E once again represents the pump stroke length supplied by the movement of end cap member 111 from the depression of trigger member 91, and arrow D represents the movement of the flexible pump chamber support walls 74 as they reassume their normal disposition as illustrated in FIG. 5-A. Even though trigger member 91 has ceased to be pressed, cleaning fluid is expelled from the pump chamber 135 because of the forces exerted by the contraction of pump chamber 135, in particular the contraction of the flexible side wall 135, and the biasing force exerted by flexible pump chamber support walls 74 upon pump chamber 135. It is believed that the delayed or continuous discharge feature of the present invention (continuous discharge of fluid for approximately one second after trigger member 91 has ceased to be pressed) is thus supplied by energy stored within the pump chamber 135 by the expansion of the flexible side wall 137 and by the spring deflection of the flexible pump chamber support walls 74. It is further believed that another factor affecting the delayed discharge of the cleaning fluid from the cleaning system 60 is the fluid pressure drop across the exit hole, or safety check valve 86 associated with first fluid passageway 81, in that this pressure drop is a function of the viscosity of the cleaning fluid and the diameter of the exit hole of the cleaning system 60.
It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials or embodiment shown and described, as obvious modifications and equivalents will be apparent to one skilled in the art; for example, the flexible and expandable pump chamber could be comprised of a series of pump chambers rather than a single pump chamber; or the pump chamber could be actuated by a pulling motion rather than a pushing motion. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.
|
A cleaning system utilizing a hollow bodied, disposable dispensing capsule or package comprising a storage chamber and integral dispensing chamber made of a plastic material. The package is connected to the system handle via a conical protrusion on the package closure. An orifice separating the two chambers is provided with a movable, inlet clapper valve, the dispensing chamber outlet orifice being normally closed by a spring urged valve. Deformation of the elastic walls of the bellows shaped dispensing chamber dispenses a discrete amount of liquid to the system handle without relying on gravity. Compression of the dispensing chamber reduces the volume thereof, closes the inlet clapper valve, and opens the outlet valve to dispense the product. The conically shaped storage chamber provides for ready pumping and evacuation of cleaning fluid therefrom, the flexible walls collapsing inward as a result of the vacuum created by the decompression of the dispensing chamber.
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to pet treats and especially to means for dispensing edible pet treats in a manner to be attractive to dogs and other domestic pets.
2. Problem Presented
Edible pet treats made from rawhide, natural bone, or various other hard materials such as jerky, nylon, polyurethane, plastic and other synthetic materials are commonly used to satisfy a dog's instinctive urge to chew, reduce plaque build-up and massage gums. Additionally dogs, cats, and other domestic pets often play with non-edible toys. Examples of such toys are balls, ropes for throw and fetch, and plastic and plush toys with noise-making devices inside them which grunt or squeak when squeezed.
The problem presented by these toys is that pets have a desire and tendency to chew on items they come in contact with, which means a relatively short life span for any soft pet toy, such as plush or plastic toys with squeakers in them.
It would be desirable to extend the life of a pet plush toy by combining it with an attractive, edible pet treat that the pet would chew on and consume rather than pulling and chewing on the plush toy. Accordingly, there is a need for a toy which appeals to pets, is long-lasting, satisfies a pet's need to chew, and at the same time cleans the pet's teeth.
OBJECTS AND SUMMARY OF THE INVENTION
The present invention sets forth a pet treat dispensing system incorporating a non-edible, interactive pet toy and means in the non-edible pet toy for removably mounting or attaching an edible pet treat to place the edible treat in an exposed position so that it will be attractive to the pet and will be the pet's first choice for chewing. The attaching means allow for replacement of the edible pet treat to allow for a variety of treats and/or to extend the life of the toy by replacing the pet treat when it becomes worn or consumed, and, therefore less attractive for chewing than the toy would be.
Accordingly, it is an object of the present invention to provide a pet toy which has a means for mounting an edible pet treat in an exposed position to provide easy access for chewing by a pet.
Another object of the present invention is to provide a plush toy having a sound means or other pet attracting means which can be combined with an edible pet treat to provide a composite item for a pet, such as a dog or a cat, which will be attractive to the pet visually, for play purposes and from a consumption point of view.
It is another object of the present invention to provide a plush toy which is configured to hold large pieces of rawhide which can be used and consumed by a dog in preference to pulling, gnawing or chewing on the plush toy.
Another object of the present invention is to provide a plush toy and pet treat wherein the plush toy has means for removably mounting the pet treat.
Still another object of the present invention is to provide a plush toy for pets configured to removably hold a rawhide retriever roll to be consumed by a dog.
Yet another object of the invention is to provide a relatively durable and long-lasting toy which satisfies a dog's chewing urges and has play value for the dog.
A further object of the invention is to provide a fun pet treat dispenser which is relatively inexpensive, non-toxic, and which can accommodate a wide variety of pet treats that can be held and dispensed.
Yet another object of the invention is to provide a pet treat dispenser which has play value, is attractive, and which enables the pet owner to easily dispense pet treats.
A further object of the present invention is to provide a pet treat dispenser which retains a pet treat in a plush toy so as to reduce the contact of the edible treat with stainable surfaces in the home, such as rugs, carpets, or furniture.
It is another object of the present invention to provide a pet treat dispenser plush toy which can be used as a toy when there is no treat to dispense.
It is yet another object of the present invention to provide a plush toy which dispenses pet treats and which is durable and longer lasting than ordinary plush toys for pets.
A still further object of the invention is to provide a method for dispensing a pet treat by placing the treat in retainer means mounted to a plush toy.
Yet another object of the invention is to provide a method of dispensing pet treats in such a way that the treat is kept elevated and off the floor or furniture, by being securely held in a plush toy.
A further object of the invention is to provide a method of removably mounting an edible treat on a plush toy, which treat may be easily removed or replaced.
These and other objects are accomplished by providing a pet treat dispenser which is improved as compared to commercially available dispensers and pet toys, as it comprises a plush toy having fastening means for removably retaining a pet treat. In another aspect of the invention, there is disclosed a method of dispensing a pet treat by placing a treat in a plush toy having fastening means for removably retaining said pet treat.
These, and various other and further features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference may be had to the detailed description of the preferred embodiments taken in connection with the accompanying drawings, in which:
FIG. 1 is a front view of a pet treat dispenser according to the invention.
FIG. 2 is a back view of the pet treat dispenser of FIG. 1 .
FIG. 3 is a top view of the pet treat dispenser of FIG. 1 .
FIG. 4 is a bottom view of the pet treat dispenser of FIG. 1 .
FIG. 5 is a right side view of the dispenser of FIG. 1 .
FIG. 6 is a left side view of the dispenser of FIG. 1 .
FIG. 7 is a front view of a second embodiment of a pet treat dispenser according to the invention.
FIG. 8 is a back view of the pet treat dispenser of FIG. 7 .
FIG. 9 is a top view of the pet treat dispenser of FIG. 7 .
FIG. 10 is a bottom view of the pet treat dispenser of FIG. 7 .
FIG. 11 is a right side view of the dispenser of FIG. 7 .
FIG. 12 is a left side view of the dispenser of FIG. 7 .
FIG. 13 is a back view of the pet treat dispenser of FIG. 7 showing alternate means for removably attaching a pet treat.
FIG. 14 is a cross-sectional view through lines 14 — 14 of FIG. 13 .
FIG. 15 is a partial view showing another alternate means for removably attaching a pet treat;
Similar numerals refer to similar parts throughout the figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the FIGS. 1 through 15 , a pet treat dispenser, indicated generally by reference number 100 , is made of a plush material, preferably in the shape of an animal. The figure is formed of a flexible, plush fabric outer covering that is stuffed with a resilient, densely packed stuffing or padding material. While not critical to the invention, it is clear that the pet treat dispenser may be made of suitable materials other than plush fabric, for instance, of rubber or plastic or combinations thereof, and may be shaped to any desired appearance and configuration to appeal to pets. For example, the dispenser may be in the configuration of balls, bones, rings, rolls, retrieving objects, twists, or any other actual, novelty, or abstract shape which will pique a pet's interest.
The drawings show a pet treat dispenser, indicated generally by reference numeral 100 , which comprises a plush toy 110 such as a panda bear shown in FIGS. 1–6 , or a monkey 120 , shown in FIGS. 7–14 . Referring now to FIGS. 1–6 , the panda 110 has articulated arms 114 , on which is fastened retainer means 116 . It is contemplated that the retaining means 116 may be formed of any suitable material, such as elastic bands, rubber bands, nylon stickers or other elastic material, or adhesive means such as VELCRO®. All such materials must be flexible and soft enough not to damage the pet's teeth, and have no hard components which may detach or break into sharp fragments which the pet may ingest while playing or chewing on the treat.
The retaining means 116 is of sufficient length to encircle the pet treat at least once, and preferably is long enough to wrap around a pet treat two or more times to secure the pet treat in the arms of the plush toy treat dispenser. The retaining means are adjustable to fit virtually any size pet treat.
As shown in FIGS. 1–12 , the elastic retaining means 116 form loops fastened to each hand, preferably on the palm side, or to other parts of the pet treat dispenser, so as to hold one, two, or more separate pet treats, for instance, to hold a pet treat in both hands, or to hold two pet treats, one in each hand. Retaining means 116 may also be formed to connect both arms 114 of the plush toy, not shown, so as to hold a pet treat in both arms.
The first and second ends of the elastic retaining means are fixedly attached either to the same anchor point on an appendage of the plush toy or to different anchor points. In use, the user stretches the elastic band to loop it around the pet chew so as to retain it in position.
One or multiple elastic loops may be attached to each palm of the toy. Providing multiple retaining means enhances the stability of the plush toy. As shown in FIGS. 1–6 , one arm of the plush toy animal may be raised with respect to the second arm in a resting position, so that the elastic loops secured to the arms of the toy engage the pet treat to hold it in an upright position. The treat has a reclining orientation in the upright use position, with the treat disposed at an angle across the body of the toy figure. One end of the pet treat leans against one leg of the toy figure to stabilize the toy figure in the use position and to assist in supporting the toy in an upright position.
The pet treat is preferably a rolled rawhide pet chew treat 130 for dogs, or other animals. The pet treat is, of course, not limited to rawhide pet chews, but may comprise other types, configurations, and compositions. The pet treat 130 need not be a cylindrical retriever roll but may comprise a wide variety of treats as long as they are capable of being held within the retaining means 116 connected to the pet treat dispenser 100 . As the arms 114 of the plush pet treat dispenser 100 are articulated, the arms 114 may be moved up, down, and sideways; or the arms 114 may be raised or lowered above and below the head or feet of the plush toy. The arms 114 of the plush toy 110 may assume different positions, thus enabling the pet treat 130 to be retained in different positions with the pet treat 130 exposed for easy access by the pet.
The pet treat, generally indicated at 130 , preferably consists of a roll of rawhide which is preferably sized and dimensioned to be compatible with the size of the plush toy 110 , 120 , so that it can be, in effect, grasped or hugged by the toy 110 , 120 , so as to stabilize the pet treat 130 and, at the same time, still provide access to the pet for consumption. The pet can easily grab, chomp or gnaw, or pull and tug at the edible treat. Pet treats of different sizes and configurations may be placed and removably retained in the pet treat dispenser 100 by varying the length, width, and thickness of the retaining means 116 , so as to hold pet treats 130 of varying sizes and shapes which are suitable for pets of different breeds and sizes. The pet treat 130 is ideally designed so that the pet can easily hold it in its mouth, but cannot easily swallow it whole.
The plush toy 110 , 120 , can be moved and manipulated with respect to the pet treat 130 so that the pet treat 130 is, in effect, held at a distance from any stainable surface when the plush toy 100 is placed in its normal resting position, therefore reducing the likelihood that the pet treat 130 will stain any nearby surface.
The pet treat 130 is readily detachable from the arm 114 for independent use by the pet, yet easily re-attachable for use with the toy 100 .
As shown in FIG. 1 , the weight of the pet treat secured to the toy figure assists in maintaining the toy stationary and stable.
FIGS. 7–12 show a second embodiment of the pet treat dispenser 100 of the invention. In this case, a plush toy in the shape of a monkey 120 is shown, in which each of the arms 122 is articulated. In this embodiment, each arm 122 has separate resilient, elastic retainer means 124 to hold the pet treat and to enable the hands 126 at the end of the arms 122 to wrap around and hold the pet treat 130 . In this embodiment, the retaining means 124 comprises two elastic bands on each hand 126 to retain the pet treat 130 .
Again, in this embodiment the pet treat 130 is shown as a cylindrical roll of rawhide chew. Needless to say, various other types of plush toys can be used as long as they are capable of attaching the pet treat 130 to the toy 120 and positioning the pet treat 130 so that it is retained at a distance from any stainable surface that the toy pet treat dispenser 100 is placed upon.
When consuming the pet treat, the dog sinks its teeth into the rawhide chew and rubs the chew against its gums while savoring the latent flavor. This exercises the dog's teeth, jaws and gums, and also clean the dog's teeth by the abrasive wiping, chewing, and gnawing action of the rawhide pet treat 130 against the surface of the teeth and gums. Tarter or plaque on the pet's teeth is reduced by the action of chewing and rubbing of the chew against the teeth. The dog has a sustained interest in the pet treat and its toy dispenser, resulting in a prolonged chewing time with a beneficial increase in the abrasive effect on the dog's teeth surfaces. This helps control plaque and tartar build-up which can lead to gum disease and bad breath. Also, as the pet treat dispenser of the invention attracts and retains the pet's attention, it reduces a pet's destructive chewing.
Referring to FIGS. 13 through 15 , the retaining means may comprise a hook and loop type fastener, such as that sold under the trademark Velcro® or some other such type fastener, having a hook component 142 and a loop 144 component which forms a reattachable connection. A hook and loop type fastener may be used to attach/detach pet treats to the toy or to attach/detach several surfaces of the same article to the toy. The hook component 142 consists of a fabric backing 145 which contains a plurality of tiny, resilient, upstanding hook-shaped elements 150 . The loop component 144 of the Velcro® type fastener comprises a fabric backing 145 containing a plurality of upstanding loops 148 on its surface. When the hook component 142 and the loop component 144 are pressed together to close the fastener, the hooks 150 entangle the loops 148 and interlock, thus retaining the pet treat 130 in position. The hooks 150 and loops 148 may be disengaged by gradually peeling the components apart, so that the hooks release the loops, detaching the pet treat 130 .
Referring to FIGS. 13 and 14 , the toy's right and left hands 126 have strips of mating Velcro® type hook and loop fabric on its palm side. The hook and loop fastener strips are attached by adhesive or stitching. The dimensions of the hook and loop fastener strip will vary depending on the size of the pet chew and the size of the animal. Referring to FIG. 14 , the retaining means may comprise one hand with two portions of hook and loop fasteners on it. Alternatively, the retaining means may instead fasten, as shown in FIG. 15 , using one long strip of hook and loop fastener attached to the arm of the toy, the fastener having hook components 150 on both sides of the fabric backing 146 so as to wrap around the pet chew at least once to hold it in place. When the hook and loop type fabric strip is folded over onto itself, it forms an interior surface covered with Velcro so that it can be removably attached to itself. Each strip may be folded over on itself to any desired degree depending on how tight or lose the user wants to secure the pet treat.
To provide additional stimulation for the pet, the pet treat dispenser may include a sound means, such as a squeaker or rattle, or other pet attracting means, not shown, which may be located at a location 112 inside the head or body of the plush toy. The sound means preferably emits a sound which is attractive to the pet. In combination with the edible pet treat, the plush toy including sound means provides an attractive pet treat dispenser which is attractive to the pet visually, and which has sustained play value.
It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. For instance, the plush toy may take the form of various configurations and sizes, and may represent stuffed animals, or other objects. Rather, the invention as claimed extends to many possible variations not specifically detailed. All such variations and modifications are intended to be included in the scope of the invention as described herein.
|
A pet treat dispensing system comprising a non-edible, interactive pet toy having fastening means therein for removably mounting and retaining an edible pet treat in an exposed position for easy access by a pet, wherein the treat is kept at a distance from stainable surfaces when the toy is in the upright position.
| 0
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to vapor recovery apparatus and, in particular, to using recovered vapor for power generation.
2. Description of Related Art
Since the passage of the Clean Air Act, the Congress of the United States has required all persons or organizations handling hydrocarbons or chemicals whose vapors may pollute the air to install means to recover and prevent the contamination of the air by such vapors. Such contaminants can include vapors of gasoline, methylene chloride and other organic compounds.
Such vapors are generated and displaced into the atmosphere when all types of tanks are filled with liquid hydrocarbons or liquid chemicals. Such tanks may be large storage tanks, railroad car tanks, truck tanks, underground storage tanks for gasoline stations and fuel tanks on trucks, buses and automobiles. When these various types of tanks are filled with liquid hydrocarbons or liquid chemicals, vapors escape into the atmosphere and, as is well known, such vapors become a source of smog, which under certain ambient conditions produce dangerous fog conditions and so pollute the atmosphere that they produce dangerous environmental health hazards for human beings.
Known vapor recovery systems have used closed refrigeration cycles to cool a medium that is then used to condense vapors. Condensate can be drained to a decanter to separate heavy and light constituents, such as gasoline and water. The condensing coils for such units are periodically warmed or defrosted to prevent a build up of ice and frost that may block the passage of vapors through the condensing unit. See for example, U.S. Pat. Nos. 4,027,495; 4,068,710; 4,077,789; and 5,291,738.
Such recovery units are typically designed to handle the peak flow of vapors that may be experienced during a course of a work day. To accommodate the peak load, the recovery units are engineered with a relatively high capacity, which still may not be sufficient condense highly volatile vapors.
A disadvantage with vapor recovery systems is the energy required to run these recovery systems. Moreover, certain highly volatile vapors can only be condensed after a high expenditure of energy. Accordingly, the environmental benefits of performing vapor recovery is partially offset by the additional energy consumed to run the recovery systems.
Many industries are economically dependent on inexpensive and abundant electrical power. Many utilities will charge a rate that depends upon the peak usage or the time when the peak usage occurs. For this reason, some industries have invested in cogeneration, wherein a modest private plant for generating electricity will supplement the power from a utility to reduce the peak demand and thereby reduce the rate charged for power. Depending upon the size of the plant, some cogeneration systems can actually return power to the utility lines to earn a credit.
While in principal, a cogeneration plant can be powered by the uncondensed vapor from a vapor recovery unit, the supply of vapor tends to be sporadic and will lack a constancy that will allow cogeneration to occur in a practical way.
Such a cogeneration system may employ a generator driven by an engine that is designed to be powered by a fossil fuel. When the engine is an internal combustion engine, regulating the air/fuel ratio can be difficult when the fuel source is the uncondensed vapor from a vapor recovery unit. The uncondensed vapor can include a variety of vapors whose constituent components cannot be known in advance. Therefore, regulating the speed and power of the engine can be difficult, when the nature of the fuel, and the fuel to air ratio may vary significantly.
Furthermore, one cannot be certain in advance that the combination of a vapor recovery unit and cogeneration system will succeed in providing a net environmental benefit. In particular, the engine exhaust may introduce significant pollutants that should not be exhausted to the atmosphere.
Accordingly, there is a need to recover vapors using a combination of effective techniques such as condensing vapors, as well as using those vapors that were not condensed, in a power generation system.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a system for recovering and utilizing vapor from a source of vapor. The system has a vapor holder for storing a quantity of vapor from the source of vapor. Also included is a condensing means coupled to the vapor holder for receiving and condensing at least partially, vapor from the vapor holder. The system also has an engine, and a generator driven by the engine for generating electrical power. The engine has an engine intake coupled to the condensing means and an exhaust outlet. This engine is powered at least partially, by output from the condensing means.
In accordance with another aspect of the invention, a system for recovering and utilizing vapor from a source of vapor includes a condensing means for receiving and condensing at least partially, vapor from the source of vapor. Also included is an engine having an engine intake coupled to the condensing means, as well as a generator driven by the engine for generating electrical power. The engine is powered at least partially, by output from the condensing means. The system also has a fuel adjustment means and a fuel sensor means. The fuel adjustment means has a control input and is coupled between the engine and the condensing means for adjusting fuel concentration into the engine intake in response to a signal on the control input. The fuel sensor means is coupled to the engine intake (a) for sensing concentration of at least some constituents of vapor at the engine intake, and (b) for applying a signal to the control input of the fuel adjustment means corresponding thereto.
In accordance with still another aspect of the invention, a system for recovering and utilizing vapor from a source of vapor, has a condensing means for receiving and condensing at least partially, vapor from the source of vapor. Also included is an engine coupled to the condensing means and having an exhaust outlet for conducting exhaust from the engine. The engine is powered at least partially by output from the condensing means and drives a generator for generating electrical power. The system also includes an exhaust sensor means coupled to the exhaust outlet for providing an exhaust signal signifying concentration of at least some constituents of the exhaust at the exhaust outlet.
By employing systems of the foregoing type, vapor can be effectively recovered and utilized. In a preferred embodiment, vapor can be stored in a vapor holder, which is a vessel fitted with a flexible membrane or bag that can accommodate the varying volume of vapor to be stored. Consequently, the vapor can then be delivered at a relatively constant rate. Preferably, any engine driven by the vapor can be started or stopped should the supply in the vapor holder become relatively high or low.
In any event, the vapor can be preferably passed through a pre-cooler and a finishing condenser, both containing coils that conduct a refrigerant. Vapors condensed in these two units can be delivered to a decanter that can separate water from other more volatile liquids.
Vapors that were not condensed either because of their high volatility or because of an inadequate capacity to condense, may in the preferred embodiment, be re-heated and passed through a flame arrester to an electrical power generation system. These incoming vapors can be blended with air by means of a preferred modulating valve that is controlled by a fuel sensor, to establish a proper air/fuel ratio. The preferred fuel sensor employs an infrared detector tuned to sense concentration of a particular hydrocarbon, such as butane. The engine can drive a preferred induction generator to return power to utility lines.
Preferably, the engine exhaust can be sampled, cooled by a radiator, and delivered to a continuous emissions monitor. This monitor can have an infrared sensor tuned to a specific hydrocarbon, such as propane.
The preferred system is integrated by linking the engine coolant system to a thermal transfer system employing a vessel filled with a heated medium. The medium heated by the engine coolant system can be circulated to perform a variety of tasks. For example, the medium can be used to defrost the pre-cooler and finishing condenser, as well as the decanter. Also, the medium can be used to re-heat the uncondensed vapors delivered from the finishing condenser to the engine.
Also in the preferred embodiment, various operating parameters can be measured and provided as inputs to a programmable logic controller. This controller can use some of the input signals as feedback for controlling the system components. In other cases, the controller will simply record the parameters to keep a record of system performance.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is an elevational view of a system in accordance with the principles of the present invention;
FIG. 2 is a schematic diagram of the vapor recovery portion of the system of FIG. 1; and
FIG. 3 is a schematic diagram of the engine/generator portion of the system of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 2, a vapor holder 10 is shown as a vessel fitted with a flexible membrane or bag 12 to contain a variable volume of vapor. In one embodiment, holder 10 had a volume of 6,000 cubic feet, but different volumes may be used in other embodiments. A source of vapor 14 shown flowing into conduit 16 , can fill holder 10 . As membrane 12 moves, its position is detected by four position sensors 18 , 20 , 22 and 24 , herein referred to as a storage sensor means. Sensor 18 indicates an excessively high volume of vapor in holder 10 and may alert an operator at a loading station to cease supplying vapor from source 14 . Sensor 24 indicates an unusually low level in holder 10 and may indicate a leak, and is therefore considered an alarm. Sensor 20 indicates a modestly high volume in holder 10 and may be used to call for consumption, by starting the engine to be described hereinafter. Sensor 22 indicates a modestly low volume in holder 10 and can signal the above noted engine to stop.
Sensors 18 - 24 are transducers that respond to a mechanical input by producing electrical outputs, shown applied to a control means 26 . Control means 26 is a signal processor that can respond to a variety of input signals to produce various output signals for controlling the system described herein. Preferably, control means 26 is a programmable logic controller, which is a microprocessor-based system having a variety of input and output cards to deal with a variety of analog and digital signals. To this end, control means 26 will include a number of analog to digital and digital to analog converters. Control means 26 may also include timers to produce a delayed response to various inputs. In other embodiments, control means 26 may be a different type of computer, or may be built from discrete logic circuits. Control means 26 is shown with a plurality of other inputs and outputs, indicated as dotted lines. These dotted lines indicate an electrical signal to/from the variety of transducers illustrated in this and other diagrams.
Conduit 16 a shown fitted with an analyzer 28 that can sense its hydrocarbon content. For example, analyzer 28 may include a infrared light source tuned to detect a specific substance such as propane, butane, etc. This analyzer is employed for the purpose of reporting the hydrocarbon content and is not part of a feedback loop.
Conduit 16 a shown feeding a precooler 30 , which is part of a condensing means. Precooler 30 is shown with an internal baffle 32 positioned to create a descending upstream path and an ascending downstream path. Refrigerant circulating through coil 34 , located in the ascending downstream path, can reduce the temperature at the outlet of precooler 30 to about 35° F., although other temperatures can be established instead. The temperature at the bottom and outlet of precooler 30 can be sensed by sensors 36 and 38 , respectively. These sensors 36 and 38 are coupled to the previously mentioned control means 26 .
The output of precooler 30 flows through conduit 40 to a finishing condenser 42 , which is also part of the condensing means. Condenser 42 also has a baffle 44 to again create a descending upstream path and an ascending downstream path. Refrigerant circulating through coil 46 , located in the ascending upstream path, can reduce the temperature at the outlet of condenser 42 to about −40° F., although other temperatures may be employed in alternate embodiments. Temperature at the bottom and outlet of condenser 42 can be sensed by sensors 48 and 50 , respectively. Sensors 48 and 50 are coupled to the previously mentioned control means 26 . The refrigeration system for providing refrigerant to coils 34 and 46 is conventional and is not specifically described in this diagram.
The condensate falling onto the floors of units 30 and 42 drain through conduits 52 and 54 , respectively, to a decanter 56 . This condensate initially flows to one side of a weir 58 , which allows water to descend and eventually overflow through pipe 60 . Lighter hydrocarbon condensate will flow over the weir to the right side of decanter 56 . Three sensors 61 , 62 and 64 are used to detect whether the level of condensate in decanter 56 is too high, modestly high, or modestly low. Sensor 65 senses the temperature inside the decanter. Sensors 61 - 65 provide output signals to previously mentioned control means 26 .
Condensate from decanter 56 can be pumped by pump 66 to a storage tank (not shown), especially when sensor 61 indicates the condensate level in decanter 56 is excessively high. Pump 66 is controlled by transducer 68 , which receives its controlling input from previously mentioned control means 26 .
The line 76 has a valve 78 that can be opened to drain into decanter 56 liquid (for example, gasoline) that may have inadvertently spilled into holder 10 , Pump 66 can then be used to send this spillage to the storage tank.
Condensate in decanter 56 can also be withdrawn by pump 70 , which is controlled by a transducer 72 under the control of control means 26 . Pump 70 delivers condensate to spray heads 74 , which are also referred to herein as a saturating means. As explained further hereinafter, these spray heads can increase the concentration of fuel leaving finishing condenser 42 , when the vapor concentration is inadequate for the purposes to be described presently.
A thermal means is shown herein employing a vessel 80 filled with a medium such as a 60/40 mix of glycol and water. Vessel 80 is fitted with a temperature sensor 82 and a level sensor 84 to send monitoring signals to previously mentioned control means 26 . Vessel 80 can be heated by an electrical heater 86 , which is controlled by transducer 88 , under the influence of control means 26 . In one embodiment the medium in vessel 80 was regulated to a temperature of 130° F. At times, vessel 80 will need to be purged by nitrogen gas, which can be admitted through purge valve 90 .
The outlet of vessel 80 is drawn by pump 92 , which is under the control of transducer 94 and control means 26 . Pump 92 delivers heated liquid to heating coil 96 of reheater 98 , before returning through line 100 to vessel 80 . Reheater 98 is coupled to the outlet of condenser 42 in order to increase the temperature of vapor therefrom before delivery through conduit 99 to the engine to be described hereinafter.
The discharge from pump 92 can also circulate through condenser 42 when defrost valve 102 is opened by transducer 104 , under the influence of control means 26 . Valve 102 can be programmed to open periodically according to a schedule pre-programmed in control means 26 . For example, the defrost cycle can occur daily for about two hours. With valve 102 open, heated liquid can flow through defrost coil 106 , located in the descending upstream path of condenser 42 . Heated liquid can also flow through the defrost coils 108 mounted at the body of condenser 42 and at its outlet drain 54 . As before, coils 106 and 108 drain through line 100 to vessel 80 .
The discharge of pump 92 can also flow through defrost valve 110 under the control of transducer 112 and control means 26 . When valve 110 is open, heated liquid can flow through coils 114 and 116 . Coil 114 can defrost the liquid in decanter 56 , while coil 116 can heat the body of decanter 56 . Again, both coils 114 and 116 drain along line 100 to vessel 80 .
It will be noted by circuit 118 that the liquid of vessel 80 can circulate through another system, which will be described herein as a coolant system.
Referring to FIG. 3, previously mentioned conduit 99 is shown connected to detonation arrester 120 . Operating parameters of arrester 120 are monitored by transducer 122 which forwards its output to previously mentioned control means 26 (FIG. 2 ). The output of arrester 120 is coupled to a shut off valve 124 , which is operated by actuator 126 . Actuator 126 is operated by transducer 131 , under the control of the control means 26 . Valve 124 is used to shut down the system, not to regulate flow rates.
Shut off valve 124 feeds one inlet of modulating valve 132 , whose other inlet draws ambient air through filter 134 . The actuator 136 of modulating valve 132 is controlled by transducer 138 , under the influence of a control input from previously mentioned control means 26 . Actuator 136 is able to change the proportion of flow from the two inlets of modulating valve 132 to adjust the fuel/air ratio in engine intake 140 , and thereby act as a fuel adjustment means.
The fuel blend arriving in engine intake 140 is sensed by a fuel sensor means 141 . Means 141 employs an infrared sensor that is tuned to measure the butane in intake 140 , although other substances can be measured using different sensing means. Control means 26 (FIG. 2) senses the fuel concentration by means of transducer 144 and feeds back a control signal through transducer 138 to control the modulating valve 132 . Consequently, the control means can operate to maintain a relatively fixed concentration of fuel in engine intake 140 . In a preferred embodiment, the fuel concentration is compared to a target value to produce an error signal, which is integrated over time to produce a feedback signal for controlling the fuel adjustment means 136 , 138 .
Engine intake 140 connects to the intake manifold of engine 142 . Engine 142 may be a naturally aspirated, internal combustion, piston engine, although other engine types may be employed in different embodiments. In one embodiment engine 142 was rated at about 230 horsepower and included a microprocessor-controlled throttle that kept engine speed at at least 1,825 rpm, although other speeds and horsepower ratings are contemplated, depending upon the desired capacity and throughput.
Engine 142 has a number of sensors such as sensor 158 for measuring various operating parameters of engine 142 , such as the pressure and temperature of oil and coolant, engine speed, etc. These parameters are sent as signals to previously mentioned control means 26 . Transducer 161 is a receiver that relays control signals sent from control means 26 in order to control operating parameters of engine 142 , such as engine speed. Sensor 163 connects to a vapor detector 164 to send an alarm to the control means 26 indicating the danger of a fire or explosion due to high vapor concentrations in the engine room.
Engine 142 has an exhaust outlet 146 that delivers its exhaust through spark arrester 148 and muffler 150 before being released through stack 152 . The stack temperature is measured by transducer 154 , which delivers an output to previously mentioned control means 26 . Blower 156 sends ambient air to mix with the exhaust arriving at the inlet to spark arrester 148 , and thereby act as a mixing means. Blower 156 will dilute the exhaust to reduce its temperature and thereby reduce the danger of ignition, which can be important in a division 1 explosion proof rated area.
Engine 142 has a coolant system with a coolant outlet that connects to a radiator means, shown herein as radiator 158 . Radiator 158 is cooled by an electric fan 160 controlled by transducer 162 , in response to signals from the previously mentioned control means 26 . Radiator 158 can be bypassed by valve 164 in response to temperature regulator 166 , in order to keep the output temperature on line 167 at a regulated value, for example 130° F. Line 167 is shown passing through circuit 118 . As previously mentioned, circuit 118 circulates through vessel 80 (FIG. 2 ).
Coolant returning from circuit 118 passes through one side of heat exchanger 168 before returning to the coolant inlet of engine 142 . The other side of exchanger 168 receives oil from an oil outlet of engine 142 in order to cool the oil. Oil leaving exchanger 168 passes through oil filter 170 before returning to an oil inlet of engine 142 . Engine oil temperature is measured by transducer 172 , which forwards its measurement to the previously mentioned control means 26 .
A sample of the exhaust from exhaust outlet 146 is drawn from sampling line 174 and cooled by cooler 176 , a radiator positioned next to radiator 158 so both can be cooled by the same fan 160 . The cooled exhaust sample from cooler 176 is delivered to an exhaust sensor means 178 .
Sensor means 178 can include an infrared sensor tuned to detect a specific hydrocarbon in the exhaust, for example, propane. Sensor means 178 can also include other types of sensors including an oxygen sensor. In one embodiment, sensor means 178 forwarded its measurement through transducer 180 to the previously mentioned control means 26 , which acts to shut down engine 142 if the propane level exceeds 10%. Sensor means 178 includes an inlet chamber with internal spiral corrugations to swirl the incoming exhaust and thereby centrifugally remove water droplets.
Sensor means 178 acts as a continuous emission monitoring system (CEMS) for recording emissions from the engine 142 . The exhaust signal from transducer 180 is monitored by control means 26 to perform a five-minute average. These five-minute averages are later converted to a one hour average. This data is kept as a record that can be printed out through the control means 26 for the purpose of documenting emissions compliance.
The output shaft 182 of engine 142 drives an induction generator 184 . Various operating parameters of the generator 184 (speed, voltage, current, temperature, etc.) can be monitored by transducers such as transducer 186 , whose output signal is sent to previously mentioned control means 26 . Also, transducer 187 is a receiver that relays control signals from previously mentioned control means 26 , in order to control operating parameters of the generator 184 . Generator 184 can be rated to deliver 125 kW, at 200 A and 60 Hz, although this rating can vary depending upon the system capacity or other requirements. It is highly desirable to keep the rating of generator 184 such that it will demand only approximately 30% to 40% of the rated horsepower of the engine 142 . A phase sequence relay 188 connected to generator 184 performs the conventional phase sequencing under the control of transducer 190 in accordance with signals from the previously mentioned control means 26 .
Three phase output power is provided by generator 184 on lines 192 to a switching means 194 . Switching means 194 can interrupt lines 192 when the output from generator 184 is low (when the motor is running slowly or stopped), or when a thermal overload is detected. Also, switching means 194 can be switched off under the influence of receiver 196 , which is controlled by control means 26 . Power transferred through switching means 194 can be measured by power meter 198 , whose measurement is sent through transmitter 199 to previously mentioned control means 26 .
Referring to FIG. 1, the present system is shown installed atop a pair of lifting beams 202 . A first compartment 204 and second compartment 206 are positively pressurized by a fan 208 , which draws remote air down through stack 210 for that purpose. Compartment 204 contains a compressor 212 and air cooled condenser 214 that provide refrigerant to the previously mentioned pre-cooler 30 and finishing condenser 42 (FIGS. 1 and 2 ). Compartment 204 also contains the previously mentioned control means and other electrical equipment.
Compartment 206 contains previously mentioned engine 142 and generator 184 . The previously mentioned spark arrester 148 and muffler 150 are shown projecting above compartment 206 . The previously mentioned fan/radiator combination 158 , 160 is shown mounted between compartment 206 and a third compartment 214 . Vapor source inlet 14 is shown feeding into compartment 214 , which contains the previously mentioned precooler 30 and finishing condenser 42 . The output of finishing condenser 42 is shown connecting to reheater 98 .
It will be appreciated that different physical arrangements may be implemented. For example, the various components can be arranged in a different spatial order. Alternatively, the various components can be arranged as separate modules that may be interconnected by appropriate ducts, pipes, lines, etc.
To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly described. The system illustrated in FIG. 1 can be installed near a source of vapor that feeds inlet 14 . This vapor source can be vapors that are displaced when a gasoline tanker truck is filled, or vapors from some other process. Vapors produced in quantity can be stored in vapor holder 10 (FIG. 2 ), whose membrane 12 rises as the volume of stored vapors increases. As the stored vapors increase, eventually sensor 20 signals control means 26 , which then attempts to start engine 142 .
First, valve 128 (FIG. 3) is opened to cause transducer 126 to open the shut off valve 124 , thus providing a fuel path to engine 142 . Engine 142 is cranked for a predetermined amount of time, while engine speed is monitored. If engine speed does not rise to level indicating a start, the cranking ceases and shut off valve 124 is closed again. Control means 26 will repeat this procedure two more times, if necessary.
If the engine does start, a partial vacuum is drawn through engine intake 140 , which is communicated through conduit 99 , units 30 and 42 , and conduit 16 , which connects to vapor holder 10 . Consequently, vapor is drawn from holder 10 , and possibly from vapor source 14 into precooler 30 . Refrigerant circulating through coil 34 essentially causes the water vapor present in the vapor stream to condense and drain through pipe 52 to a position behind weir 58 in decanter 56 . Since the temperature of vapor leaving through conduit 40 is only about 35° F., the more volatile vapors are not condensed and are instead delivered to finishing condenser 42 .
In finishing condenser 42 , refrigerant circulating through coil 46 reduces the temperature to about −40° F. to condense the more volatile vapors. These condensed vapors drain through pipe 54 to a position behind weir 58 in decanter 56 . Accordingly, decanter 56 has a combination of water and liquid hydrocarbons behind weir 58 . Since the water is heavier, it descends and discharges through overflow pipe 60 . The incoming liquid hydrocarbons eventually spill over weir 58 .
At times, vapor source 14 will result from the displacement caused by the loading of a truck that normally handles such distillates as diesel fuel, home heating oil, kerosene, jet fuel, and other less volatile liquids. In that case, vapor holder 10 will have insufficient combustible vapor for eventually running engine 142 . For this reason, pump 70 will normally be activated whenever engine 142 is running. This causes a return of condensed hydrocarbons back to the saturating spray heads 74 in finishing condenser 42 . Spray heads 74 will atomize the returning liquid into a fine mist that can be easily combusted by engine 142 . In some embodiments pump 70 can be started manually, or when sensor 28 detects a low hydrocarbon vapor content in conduit 16 . In cases where a more volatile vapor is being handled (e.g., gasoline vapors) the saturating spray heads 74 may not be used at all.
The liquid medium in vessel 80 has been warmed by regulated electric heater 86 , or by the engine coolant flowing through circuit 118 . Whenever engine 142 is running, pump 92 also runs to circulate the heated medium in vessel 80 through warming coil 96 of reheater 98 . This increases the temperature of the rather cold vapor that would otherwise come from finishing condenser 42 . This warming of the output of condenser 42 allows for easier combustion in engine 142 .
After passing through flame arrester 120 (FIG. 3 ), fuel is mixed with air at modulating valve 132 . Modulating valve 132 determines the balance between fuel and air, based on the hydrocarbon measurements performed by fuel adjustment sensor 141 . Preferably, an infrared sensor in sensor 141 detects the level of butane in conduit 140 and compares that measurement to a target value. The difference from this target value is time integrated in control means 26 (FIG. 2) to produce a feedback signal that is applied through transducer 138 to the actuator 136 of the modulating valve 132 .
As the engine warms up, electric fan 160 will eventually be turned on by control means 26 when the temperature of engine 142 rises sufficiently, as measured by one of the transducers, such as transducer 158 . Engine coolant is kept at a temperature of 130° F., under the regulation of bypass valve 164 . This coolant flow is used to cool oil by circulating through heat exchanger 168 . The coolant flow diverted through circuit 118 also works to bring the temperature of the medium in vessel 80 (FIG. 2) to a temperature of about 130° F., without the need for electric heater 86 .
The exhaust from engine 142 flows from outlet 146 , mixes with cooling air from blower 156 , and passes through spark arrester 148 and muffler 150 before being discharged through stack 152 .
As engine 142 reaches a speed of at least 1825 rpm, generator 184 may now be able to produce a power output that is sufficient to deliver power to the utility lines 200 . If the operating parameters of generator 184 , as measured by transducer 186 , are favorable, switch means 194 may be closed by means of transducer 196 , under the control of control means 26 . Once switch means 194 is closed, the power output is measured by power meter 198 .
Since generator 184 is an induction generator, its power output can be increased if needed by increasing its speed. When increased speed is needed, control means 26 sends appropriate signals through transducer 161 , requesting the microprocessor-controlled throttle of engine 142 to increase the engine speed appropriately. In the preferred design, the throughput of vapor is limited by the capacity of engine 142 . Typically, precooler 30 and finishing condenser 42 can deliver more fuel (either as uncondensed vapor or by spraying condensed liquid by means of spray head 74 in condenser 42 ) than engine 142 can handle without reaching an unacceptably high speed.
Control means 26 has a timer for periodically scheduling a defrost cycle. In some embodiments, defrosting may occur for two hours once every day. When a defrost cycle is initiated, valves 102 and 110 (FIG. 2) are opened by transducers 104 and 112 , respectively, under the influence of control means 26 . Consequently, pump 92 causes heated medium to flow through coils 106 , 108 , 114 , and 116 . As a result, ice that may have formed at condenser 42 or decanter 56 will be melted. At the end of the defrost cycle, valves 102 and 110 will be closed by control means 26 .
Since the delivery of vapors from source 14 can be sporadic, storage in vapor holder 10 will allow a more continuous delivery of vapor through conduit 16 into precooler 30 . At times however, vapor holder 10 will be depleted to the point that level sensor 22 signals a low condition to control means 26 . In response, control means 26 sends a command through a transducer, such as transducer 161 , to stop engine 142 (FIG. 3 ). Also, control means 26 will send a signal through transducer 131 to close valve 128 , which causes actuator 126 to close the shut off valve 124 in order to stop the delivery of fuel to engine 142 . Shut off valve 124 can also close under emergency conditions. For example, vapor detector 164 , or a smoke or fire detector, may produce an alarm signal that closes valve 124 under such conditions.
It is appreciated that various modifications may be implemented with respect to the above described, preferred embodiment. While an internal combustion, piston engine is illustrated, in other embodiments other types of engines may be used, including turbine engines. While vapor condensation is performed in two stages herein, in other embodiments the condensation can be performed in a fewer or greater number of stages. While a specific topology is shown for routing a coolant and heating medium, in other embodiments that topology can be arranged in a variety of ways to include different serial or parallel connections, or to include independent systems. Specifically, in some embodiments the defrosting system can be separate from the engine coolant system. While a weir is shown for separating water, in other embodiments different types of separation systems can be used, including centrifugal separation. A plurality of independent control systems, each using one of a variety of technologies, can be used instead of the single control means disclosed herein. Also, a variety of valves may be used that are controlled in a variety of ways including hydraulically, electrically, pneumatically, etc. Furthermore, a greater or lesser number of operating parameters can be measured in comparison to those measured in this disclosure.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
|
A system for recovering and utilizing vapor from a source of vapor has a vapor holder for storing a quantity of vapor from the source of vapor. Also included is a condenser coupled to the vapor holder for receiving and condensing at least partially, vapor from the vapor holder. The system also has an engine and a generator driven by the engine for generating electrical power. The engine has an engine intake coupled to the condenser and an exhaust outlet. This engine is powered at least partially, by output from the condensing apparatus. The system also has a fuel adjustment apparatus and a fuel sensor apparatus. The fuel adjustment apparatus has a control input and is coupled between the engine and the condensing apparatus for adjusting fuel concentration into the engine intake in response to a signal on the control input. The fuel sensor apparatus is coupled to the engine intake (a) for sensing concentration of at least some constituents of vapor at the engine intake, and (b) for applying a signal to the control input of the fuel adjustment apparatus corresponding thereto. The system also includes an exhaust sensor apparatus coupled to the exhaust outlet for providing an exhaust signal signifying concentration of at least some constituents of the exhaust at the exhaust outlet.
| 5
|
CROSS REFERENCE TO RELATED APPLICATIONS
Reference is made to the following copending applications filed concurrently herewith: application Ser. No. 131,163 entitled "Process Unit Incorporating A Charging Device" in the name of Alan C. R. Howard et al. application Ser. No. 131,075 entitled "Process Unit For An Imaging Apparatus" in the name of Alan C. R. Howard et al.; application Ser. No. 131,074 entitled "Process Unit For An Imaging Apparatus" in the name of Alan C. R. Howard et al; application Ser. No. 130,920 entitled "Electrostatographic Reproducing Machine and Process Unit Therefore" in the name of David M. Newbury; application Ser. No. 131,073 entitled "Fiber Traps in Copiers" in the name of Philip R. Thompson. Reference is also made to copending application Ser. No. 038,093 entitled "Process Unit For An Imaging Apparatus" filed Apr. 14, 1987 in the name of Robert A. Carter.
BACKGROUND OF THE INVENTION
This invention relates to a process unit adapted to be removably mounted in a main assembly of an electrostatographic reproducing machine, the unit comprising a housing and an imaging member inside the housing. The invention further relates to an electrostatographic reproducing machine employing such a process unit.
In the art of electrostatographic reproduction there is a trend to incorporate the imaging member, i.e. the photoreceptor, together with other process means such as a charge corotron, a development device, and a cleaning device in a removable process unit or so-called cassette as disclosed for example, in U.S. Pat. No. 3,985,436 to Tanaka et al. The use of such a cassette enables the easy replacement of those parts of the copying machine which are most likely to deteriorate with use, especially the photoreceptor, but also the development and cleaning systems as well as the charge corotron wire. A further advantage of containing the major process elements within a cassette is that interchangeable cassettes may be used in a given copying machine to provide different development characteristics or different coloured development.
A problem with the cassette disclosed in U.S. Pat. No. 3,985,436 is that when it is removed from the main assembly of the copying machine the part of the imaging member where image transfer occurs in the copying machine is unprotected and is therefore susceptible to damage or contamination, and also to light exposure which can result in premature deterioration of the photosensitive material on the imaging member. Needless to say, these adverse affects are likely to impair the quality of image formation.
PRIOR ART
With a view to overcoming this problem it has been proposed to provide a cassette with a retractable cover for shielding and protecting the imaging member. For example, U.S. Pat. No. 4,470,689 to Nomura et al discloses a cassette with a movable cover mounted below the cassette housing, but integral therewith. An actuating device is included whereby the cover is automatically rotated to a closed position to shield the imaging member when the cassette is removed from the main assembly of the copying machine, and when the cassete is inserted into the main assembly the cover is automatically rotated to an open position to expose the imaging member at the area where image transfer occurs. The arrangement is such that the cover remains open during normal operation of the machine.
A similar protection cover for a process unit is described in U.S. Pat. No. 4,462,677 to Onoda wherein the cover is moved from a protective position to an open position in response to another operation of the main apparatus such as for example opening the machine to remove a paper jam. These arrangements suffer the drawback that they employ relatively elaborate mounting and actuating mechanisms for the covers which are likely to result in increased cost and diminished reliability.
U.S. Pat. No. 4,609,276 to Mitzutani illustrates similar process units for use in image formation apparatus. FIGS. 10A through 10G illustrate several alternative arrangements for a process unit to contain various process means. FIG. 10G illustrates such a unit which in addition to including an imaging drum, charging device and developer also includes a transfer discharger and a protective cover. In this regard attention is also directed to the discussion in Onoda of FIGS. 13A to 13F at column 8, lines 35 to 64 and Nomura et al of FIGS. 15A to 15F at column 8 lines 15 to 45 concerning the inclusion of a transfer discharger in the process unit.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention there is provided a process unit adapted to be removably mounted in a main assembly of an electrostatographic reproducing machine, the process unit comprising a housing, an imaging member inside the housing, the housing having an aperture through which a copy sheet may enter the process unit for transferring an image from the imaging member to the copy sheet when the process unit is installed in the main assembly, and means providing an opaque cover which is arranged normally to adopt a closed position covering the aperture, the cover means being adapted to be displaced from the closed position by the action of an entering copy sheet bearing against it thereby enabling the copy sheet to enter the process unit.
With this process unit it is intended that the copy sheet actually enters the unit itself through an aperture provided in the unit housing. Image transfer from the imaging member to the copy sheet can thus be effected within the interior of the process unit. This is advantageous because the aperture need only be relatively narrow to enable a copy sheet to enter, thus dispensing with the need for elaborate cover mechanisms of the kind found in the prior art. By contrast, the process unit of the present invention uses only a very simple cover member, for example in the form of a resilient flap or a brush, which is readily displaced by the action of an entering copy sheet bearing against it.
Suitably the transfer charging device is included as part of the process unit and, more especially, as part of the unit housing. In this case the transfer charging device itself shields and protects the imaging member from light exposure, damage, and contamination when the unit is removed from the main assembly of the copying machine.
An additional advantage of having the transfer charging device integral with the unit housing is that the transfer charging device will be replaced automatically whenever the process unit is exchanged for a fresh one without having to change the transfer charging device separately.
According to a further aspect of the invention there is provided an electrostatographic copying machine employing a process unit in accordance with the first aspect of the invention.
In one embodiment, a guide member formed integrally with the housing is also included for guiding copy sheets to the aperture. This guide member may comprise an extended portion of the transfer charging device.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a schematic cross section of a process unit having an integral transfer corotron in accordance with the invention,
FIG. 2 is a schematic cross section of the process unit taken on the line II--II in FIG. 1,
FIG. 3 is a cross section showing detail of a latch mechanism for retaining the corotron in the process unit taken on the line III--III in FIG. 2, and
FIG. 4 is a schematic view in cross section of a reproducing machine having a process cassette according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
It is noted that for the sake of clarity the Figures are not drawn to scale. In particular, in FIG. 2, the dimensions in the vertical direction have been exaggerated. The same features are denoted by the same reference numerals in each of the Figures.
The process unit or cassette 1 shown in FIG. 1 is designed to be removably mounted in the main assembly of a xerographic copier as described, for example, in the aforementioned U.S. Patents and also in our copending U.S. patent application Ser. No. 038,093 filed Apr. 14, 1987, entitled Process Unit For An Imaging Apparatus in the name of Robert A. Carter commonly assigned to the assignee of the present invention.
The cassette 1 comprises a housing 2 made for example, primarily of polystyrene which encloses an imaging member in the form of a belt photoreceptor 3 in addition to various process means, in particular a development device 4, a cleaner 5, and a charge corotron 6. The belt photoreceptor is an endless flexible belt 3 having a photosensitive surface. In the arrangement shown, when the cassette 1 is removed from the main assembly 100 of the copier the belt is only loosely retained in the cassette, but when the cassette is inserted into the main assembly of the copying machine the photoreceptor belt is supported in an operative position by a member (not shown) forming part of the main assembly. A cassette having this kind of loosely retained photoreceptor arrangement forms the subect of our above referenced copending U.S. patent application Ser. No. 038,093 to which reference is invited for further details.
Returning to the present FIG. 1, a transfer charging device 7 is included in the cassette housing in the vicinity of the photoreceptor belt at the area where a toner image is to be transferred from the belt to a copy sheet. The technique of actually transferring a toner image is well known to those skilled in the art and no further details need be given here. The transfer charging device 7 is in the form of a corotron having an outer shield 8 which, as is conventional, is substantially U-shaped and made for example of stainless steel. A corona wire 9 extends the full length of the shield 8 and is spaced apart from the walls thereof in the usual manner.
At its upper end the shield has extended portions 10 and 11 on its left- and right-hand sides respectively, as viewed in the drawing. These portions 10 and 11 define the path which a copy sheet follows as it passes through the cassette for the purposes of having a toner image transferred thereto, as described in more detail below.
The manner in which the transfer corotron 7 is fixed to the cassette housing 2 will now be described.
As shown in FIG. 2, the corotron 7 has end caps 21, 22 fastened to opposite ends of shield 8. The end caps 21, 22 are made of a plastics material. End cap 21 has a projecting pin extending from its side faces both into and out of the plane of FIG. 2. The pin 23 is accommodated in sockets 24 formed integrally in the cassette housing 2. Two such sockets 24 are provied, one on each side of the end cap 21. At the opposite end of the corotron 7, the other end cap 22 has a projecting tab 25 which engages in a latch mechanism 26 as shown more clearly in FIG. 3. The tab 25 is held by two jaws 27a, 27b of the latch which are biased together by an inverted keyhole-shaped spring 28. The spring 28 is held in place by pairs of tabs 29a, 29b; 30a, 30b formed integrally on the inward face of the jaws 27a, 27b. The upper portion of each jaw 27a, 27b is provided with a protruding post 31 a, 31b with an enlarged head 33a, 33b extending from the outward face. The posts 31a, 31b are accommodated in slots 32a, 32b respectively in the cassette housing, thus providing a pivotal mounting for the jaws. The enlarged heads 33a, 33b which act to retain the latch in its own plane are present on the outside of the cassette housing as can be seen most clearly in FIG. 2. The latch is also held in place by two bail bars 34a, 34b formed on a recessed portion of the internal wall of the cassette housing 2. The bail bars 34a, 34b are both joined to the cassette housing at each of their two ends, thereby providing a slot between the bars and the cassette housing through which the jaws 27a, 27b are threaded, thereby limiting their pivotal movement as well as holding them in their own plane (see FIG. 3). When the cassette is outside the main assembly of the copying machine the jaws 27a, 27b of the latch 26 are closed to support the corotron as shown in FIG. 3. However, the latch is adapted to be opened automatically to release the corotron when the cassette is inserted into the main assembly of a copying machine, which enables the corotron to be located accurately relative to the photoreceptor when it is in the operative position in the machine and also enables the corotron to be hinged open about pivot pin 23 to allow for clearance of jammed copy sheets. These features are the subject of our above referenced copending patent applications Ser. Nos. 131,163 and 131,074 to which reference is inited for further details. It is noted, however, that it is not necessary for the transfer corotron 7 to have a hinge and latch mounting as described above. Instead the transfer corotron 7 may for example simply be fixed rigidly at each of its two ends to the side walls of the cassette housing 2.
As can be seen from the Figures, the outside of the corotron shield 8 forms part of the external wall of the housing 2.
An aperture 14 is present between the right-hand extension 11 of corotron shield 8 and the main part of the cassette housing to enable a copy sheet to enter the process unit for the purpose of transferring an image thereto from the photoreceptor belt 3 in the vicinity of the transfer corotron when the cassette is inserted into the main assembly of the copying machine. The aperture 14 is in the form of a slot extending substantially the full width of the cassette but being relatively narrow, for example 2 mm wide. An opaque cover 21 in the form of a resilient flap is located over the aperture 14. The cover flap 21, which may suitably be made of a polyester or polycarbonate material is secured by adhesive to the underside of the main part of the housing 2 at the downstream side relative to the direction of travel of a copy sheet entering the cassette. The downstream side of the flap, which is free, extends a short way into the process unit and by virtue of its inherent resilience bears lightly against the upper side of the ramp portion 17 of the corotron shield extension 11.
The path which a copy sheet follows as it passes through the cassette for image transfer purposes is denoted by an arrow in FIG. 1. The external wall portion 15 of the main part of the cassette housing is shaped so as to deflect and guide the approaching copy sheets towards the aperture 14. Furthermore, the extreme right-hand side of the extended portion 11 of corotron shield 8 has a steeply downturned lip 16 adjoining the less steeply inclined ramp portion 17. The downturned lip 16 and ramp portion 17 thus also act to guide approaching copy sheets towards the aperture 14.
As an approaching copy sheet arrives and bears against the cover flap 21 it causes the flap to yield under its own flexibility and so the cover is raised slightly at the area of the ramp portion 17 permitting the copy sheet to pass by and enter the cassette through the aperture 14.
As the copy sheet enters the cassette it follows the path defined between the photoreceptor belt 3 and the ramp portion 17 of the corotron shield extension 11. The copy sheet then passes over the main part (i.e. the shield 8 and the wire 9) of the transfer corotron 7 where the toner image is transferred from the photoreceptor belt to the copy sheet itself in known manner. From there the copy sheet traverses the slightly upwardly inclined ramp 18 forming part of the shield extension 10 on the left hand side of the corotron 7, and thence to aperture 20 in the cassette housing where the copy sheets exits the cassette for further processing, in particular for the toner image to be fixed permanently to the copy sheet using techniques well known to persons skilled in the art. When the trail edge of the copy sheet leaves the aperture 14 the cover flap 21 reverts to its initial rest position bearing against the ramp portion 17 of cororon shield extension 11 by virtue of its own resilience, thereby re-closing the aperture 14 until the next copy sheet arrives.
Referring now to FIG. 4, there is shown schematically a xerographic printing machine 110 having the removable process unit 1 of the present invention in its operational position in the main assembly 100. The machine includes an endless flexible photoreceptor belt 1 mounted for rotation in the clockwise direction as shown about support rollers 111a and 111b to carry the photosensitive imaging surface 112 of the belt 3 sequentially through a series of xerographic processing stations, namely a charging station 114, an imaging station 116, a development station 118, a transfer station 120, and a cleaning station 122.
The charging station 114 comprises a corotron 6 which deposits a uniform electrostatic charge on the photoreceptor belt 3. The photoreceptor belt 3, the charge corotron 6, the developer device 4, the transfer corotron 7, and the blade cleaner 5 may all be incorporated in a process cassette 1 adapted to be removably mounted in the main assembly 100 of the xerographic copier as described in aforementioned copending application Ser. No. 038,093.
An original document D to be reproduced is positioned on a platen 124 and is illuminated in known manner a narrow strip at a time by a light source comprising a tungsten halogen lamp 126. Light from the lamp is concentrated by an elliptical reflector 125 to cast a narrow strip of light on to the side of the original document D facing the platen 124. Document D thus exposed is imaged on to the photoreceptor 1 via a system of mirrors M1 to M6 and a focusing lens 127. The optical image selectively discharges the photoreceptor in image configuration, whereby an electrostatic latent image of the original document is laid down on the belt surface at imaging station 116. In order to copy the whole original document the lamp 126, the reflector 125, and mirror M1 are mounted on a full rate carriage (not shown) which travels laterally at a given speed directly below the platen and thereby scans the whole document. Because of the folded optical path the mirrors M2 and M3 are mounted on another carriage (not shown) which travels laterally at half the speed of the full rate carriage in order to maintain the optical path constant. The photoreceptor 1 is also in motion whereby the image is laid down strip by strip to reproduce the whole of the original document as an image on the photoreceptor.
By varying the speed of the scan carriages relative to the photoreceptor belt 1 it is possible to alter the size of the image along the length of the belt, i.e. in the scanning direction. In full size copying, that is to say with unity magnification, the speed of the full rate carriage and the speed of the photoreceptor belt are equal. Increasing the speed of the scan carriage makes the image shorter, i.e. reduction, and decreasing the speed of the scan carriage makes the image longer, i.e. magnification.
The image size can also be varied in the direction orthogonal to the scan direction by moving the lens 127 along its optical axis closer to the original document i.e. closer to mirrors M2 and M3, for magnification greater than unity, and away from the mirrors M2 and M3 for reduction, i.e. magnification less than unity. When the lens 127 is moved, the length of the optical path between the lens and the photoreceptor, i.e. the image distance, is also varied by moving mirrors M4 and M5 in unison to ensure that the image is properly focuse on the photoreceptor 1. For this purpose mirrors M4 and M5 are suitably mounted on a further carriage (not shown).
At the development station 118, a magnetic brush developer device with a developer roll 128 develops the electrostatic latent image into visible form. Here, toner is dispensed from a hopper (not shown) into developer housing 129 which contains a two-component developer mixture comprising a magnetically attractable carrier and the toner, which is deposited on the charged area of belt 1 by a developer roll 128.
The developed image is transferred at transfer station 120 from the belt to a sheet of copy paper according to the practice of the present invention. The copy paper is delivered into contact with the belt in synchronous relation to the image from a paper supply system 131 in which a stack of paper copy sheets 132 is stored on a tray 133. The top sheet of the stack in the tray is brought, as required, into feeding engagement with a top sheet separator/feeder 134. Sheet feeder 134 feeds the top copy sheet of the stack towards the photoreceptor around a 180° path via two sets of nip roll pairs 135 and 136. The path followed by the copy sheets through the aperture in the cassette is denoted by a broken line. At the transfer station 120 transfer corotron 7 provides the electric field to assist in the transfer of the toner particles thereto.
The copy sheet bearing the developed image is then stripped from the belt 1 and subsequently conveyed to a fusing station 138 which comprises a heated roll fuser 139 to which release oil may be applied in known manner. The image is fixed to the copy sheet by the heat and pressure in the nip between the two rolls 139 and 140 of the fuser. The final copy is fed by the fuser rolls into catch tray 141 via two further nip roll pairs 142 and 143.
After transfer of the developed image from the belt some toner particles usually remain on the surface of the belt, and these are removed at the cleaning station 122 by a cleaner blade 5 which scrapes residual toner from the belt. The toner particles thus removed fall into a receptacle 145 below. Also, any electrostatic charges remaining on the belt are discharged by exposure to an erase lamp 146 which provides an even distribution of light across the photoreceptor surface. The photoreceptor is then ready to be charged again the the charging corotron 6 as the first step in the next copy cycle.
The patents and applications referred to herein are hereby specifically and totally incorporated herein by reference.
From the foregoing it will be evident that various modifications may be made within the scope of the present invention. For example, instead of a flexible flap the cover for the aperture in the cassette housing may be formed by a brush. Also, instead of a flexible belt the imaging member may comprise a photoreceptor drum as commonly used in xerographic machines. Moreover, apart from the transfer cororon, the cassette may enclose additional or alternative processing means to those described above. In addition, while the invention has been illustrated with respect to copying apparatus it will be understood that it may be used in printer apparatus where a light beam such as a laser beam may be used to selectively discharge portions of the photoconductor. All such modifications and embodiments as may readily occur to the artisan are intended to be within the scope of the appended claim.
|
A process unit which can be removably mounted in a main assembly of an electrostatographic copying machine has a housing enclosing an imaging member and, optionally, other processing means such as a development device, a cleaner, and a charge corotron. The transfer corotron, for transferring a toner image from the photoreceptor to a copy sheet is preferably incorporated in the cassette housing. An aperture is present in the housing adjacent corotron so that a copy sheet can enter the unit to have an image transferred thereto from the photoreceptor. A simple resilient cover flap is provided over the aperture which protects the imaging member from contamination, physical damage, and light exposure when the cassette is removed from the main assembly of the copier. The flap is readily displaced as an entering copy sheet bears against it, thus enabling a copy sheet to pass. As the trail edge of the copy sheet leaves the aperture the resilient flap reverts to its former position in which it closes the aperture until the arrival of a subsequent copy sheet. Instead of a resilient flap the cover may be formed by a brush.
| 6
|
FIELD OF THE INVENTION
This invention relates to a method and apparatus for refilling disposable ink cartridges of ink jet printheads from ink reservoirs located off-board the printhead carriages. The pressure in ink lines connecting the off board reservoirs to the cartridges is monitored prior to and during a refill operation so that refilling is prohibited or stopped if an ink line is open to atmospheric pressure.
BACKGROUND OF THE INVENTION
To reduce printhead carriage mass so as to obtain high carriage accelerations and velocities, ink jet printers are provided with ink reservoirs located off-board the carriages, ink in these reservoirs being used to replenish ink drawn from the printhead cartridge reservoirs during printing. The refill may take place continuously or intermittently. For continuous refilling, the off-board reservoirs may be connected via hoses to the printhead cartridges as shown for example in U.S. Pat. No. 5,369,429. For intermittent refilling as shown in U.S. Pat. Nos. 5,136,305, 4,967,207 and 4,968,998, the printheads are moved to a refill station where the printhead cartridges are refilled with ink from the off-board reservoirs.
Ink leakage is a particular concern in network printers using the intermittent type refill system. Such printers are frequently left running unattended for extended periods of time and, generally speaking, have larger off-board ink reservoirs. Therefore, the potential for catastrophic ink spillage exists if a leak should occur during a period when the printer is running unattended.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a refill system for intermittently refilling a cartridge reservoir of an ink jet printer from an off-board ink supply, the system providing checks for catastrophic and slow leaks prior to initiating each refill operation.
Another object of the invention is to provide a refill system for intermittently refilling the cartridge reservoir of an ink jet printer from an off-board ink supply via an ink flow path, the refill system being characterized in that the ink flow path is monitored for leaks both before and during each refill operation.
A further object of the invention is to provide a refill system for intermittently refilling the cartridge reservoir of an ink jet printer from an off-board ink supply via an ink flow path, the system being characterized in that, after each refill operation, ink is purged from the ink flow path and the path is vented to the atmosphere.
According to the invention, a refill system for intermittently refilling the cartridge reservoir of an ink jet printer from an off-board ink supply comprises an ink flow path connected to the ink supply for dispensing ink into the cartridge reservoir; a pressure detector; an air pump; a pressure control valve for selectively connecting the ink flow path and the ink supply to the air pump; a controller responsive to the pressure detector for controlling the pump and the pressure control valve to apply air at a test pressure from the pump to the ink flow path to check for leaks in the ink flow path, and apply air at an ink feed pressure from the pump to the ink supply to feed ink from the ink supply through the ink flow path to the cartridge reservoir. A dispensing valve blocks the ink flow path during the interval the test pressure is being applied and vents the ink flow path to the atmosphere after a refill operation is completed. The control valve is a multiport valve having positions for connecting the ink flow path to the atmosphere or to the pump, and positions for applying atmospheric pressure or pressure from the pump to the off-board ink supply.
In accordance with one aspect of the invention, the air displacement required to raise the pressure in the ink flow path from atmospheric pressure to the ink flow pressure is measured and utilized as an indication of the volume of ink in the off-board ink supply prior to initiating an ink transfer.
In accordance with a further aspect of the invention, an ink level sensor is provided in the cartridge reservoir for sensing the level of ink therein. During a refill operation the controller monitors the ink level sensor to determine if the ink level is continuously rising. If the ink level is not continuously rising, the refill operation is terminated and an indicator is set. In an alternative embodiment, one of two indicators may be set depending on the saved indication of the volume of ink in the off-board ink supply prior to initiating the ink transfer.
Other objects and advantages of the invention will become obvious upon consideration of the following description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates an ink supply system according to the invention;
FIG. 2 is a sectional view of a pressure sensor suitable for use in the ink supply system;
FIG. 3 is a block diagram illustrating electrical connections between components of the ink supply system;
FIGS. 4A-4D illustrate four positions of a control valve used to control pressure in the system; and,
FIGS. 5A and 5B illustrate a dispensing valve in a dispensing position (FIG. 5A) and a venting position (FIG. 5 B).
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates an ink supply system 10 for replenishing the ink supply in a single, preferably foam-filled, ink reservoir 12 of a printhead cartridge 14 . The cartridge 14 is conventional and is mounted in a conventional manner on a printhead carriage 16 slidable back and forth on a support shaft 17 so that the cartridge may be moved back and forth during printing or moved to a refill station (not shown) when the supply of ink in reservoir 12 must be replenished.
Ink supply system 10 comprises a pump or pressure source 18 , an off-board ink reservoir 20 , a pressure control valve 22 , a dispensing valve 24 and a pressure sensor 26 . Pressure source 18 may, for example, comprise a pump or bellows 28 and an electric drive motor 30 for alternately expanding and contracting the bellows, but other pressure sources may be used provided they may be controlled as subsequently described to vary the pressure in an air line 32 connected to the chamber 29 of the bellows.
The off-board reservoir 20 may also be of conventional design but preferably comprises an air-tight rigid hollow shell 34 having therein a bladder or sac 36 filled with ink. The shell is provided with first and second openings 38 , 40 which are sealed by elastic barriers that are pierceable by hollow needles (not shown). One needle connects with an air line 42 and the other needle connects with an ink flow path, comprising lines 44 and 64 , through a check valve 45 . When cartridge reservoir 12 requires refilling, a positive pressure is applied via line 42 to the interior region of shell 34 between the shell and bladder 36 so that ink is forced out of the bladder through check valve 45 and through the ink flow path 44 , 64 .
The control valve 22 is preferably a multi-port ball valve having input ports 50 and 52 vented to atmosphere, an input port 54 connected to the air line 32 , and first and second output ports 56 and 58 . Output port 56 is connected via the air line 42 to the region between the shell 34 and bladder 36 . Output port 58 is connected via an air/ink line 60 to a T-connector 62 having arms connecting the ink output line 44 of the ink reservoir 20 to an ink line 64 which conveys ink from the reservoir to an input port 70 of dispensing valve 24 . Because the greatest exposure to ink loss is through lines 44 , 60 and 62 in the region near T-connector 62 , the sections of these lines which are below the top of reservoir 20 are strengthened to increase leak resistance.
Valve 22 has a handle 48 that is driven or stepped between four positions by electro mechanical or other drive means so as to connect the input ports of the valve to its output ports via two air passages 55 , 57 in ball 59 . The connections may be made in any one of four configurations as shown in FIGS. 4A-4D. Handle 48 is biased so that when it is not driven, valve 22 returns to the state shown in FIG. 4 D. By way of example only, handle 48 may be driven by a spring biased rotary stepper motor.
Valve 24 is a ball valve having a handle 74 that is driven or stepped between two positions (FIGS. 5A and 5B) by electro-mechanical or other drive means so as to selectively connect one of the valve input ports 68 or 70 to the output port 72 via one of two passages 69 , 71 in ball 73 . Input port 68 is vented to atmosphere and input port 70 is connected to the reservoir 20 via ink lines 64 and 44 . The ink line dispensing segment 46 is connected to the output port 72 . Handle 74 is biased so that when the handle is not driven, the dispensing line 46 is connected to atmosphere via passage 69 and input port 68 as shown in (FIG. 5 B).
Pressure sensor 26 is provided to sense the pressure in air line 32 . As illustrated in FIG. 2, the pressure sensor 26 is a low-cost digital sensor including a flexible membrane 76 which divides the interior of a housing 78 into first and second chambers 80 and 82 . Chamber 80 connects with air line 32 via an opening 84 so that air pressure in line 32 acts against the membrane 76 . A flexible electrical contact 86 is disposed within chamber 82 and connected at one end in cantilever fashion to an electrical terminal 88 . The contact 86 engages the flexible membrane 76 so that as the pressure in line 32 varies the pressure in chamber 80 to move the membrane, the free end surface 90 of the contact wipes across a plurality of arcuately disposed stationary electrical contacts 92 , 94 held within a non-conductive stationary frame 96 .
Membrane 76 is capable of moving contact 86 so that the contact end surface 90 may move over a range from below contact 92 to above contact 94 . Pressure sensor 26 , in combination with a microprocessor controller 100 (FIG. 3) monitors line 32 for three different pressures or, more accurately, three different pressure ranges. The first pressure is atmospheric pressure. When the pressure in line 32 and chamber 80 is at atmospheric pressure the surface 90 is below contact 92 so that there is no electrical connection through the sensor.
The second pressure range, referred to herein as the ‘low’ or ink feed pressure is on the order of 5 to 10 inches of water. The low pressure, when admitted to the reservoir 20 via valve 22 and line 42 , is adequate to force ink at the desired rate from reservoir 20 to the cartridge 14 via valve 24 . When the pressure in line 32 is in the ‘low’ pressure range, contact surface 90 ranges in position (moving counterclockwise) from just engaging the lower edge of contact 92 to a position just engaging the lower edge of contact 94 .
The third pressure range, referred to herein as the ‘high’ or test pressure range, is on the order of two to three times the low pressure and is used to check the system for leaks. A pressure of this magnitude causes membrane 76 to move contact 86 counterclockwise from the low to the high pressure range. While in the ‘high’ pressure range, contact surface 90 ranges in position (moving counterclockwise from the ‘low’ position) from no longer engaging the upper edge of contact 92 to a position no longer engaging the upper edge of contact 94 .
At pressures above the range of the high pressure, contact end surface 90 moves above contact 94 so that there is no electrical connection through the sensor.
The arcuate length of surface 90 is greater than the arcuate distance of frame 96 between contacts 92 and 94 so that the surface 90 may bridge or simultaneously engage both contacts. The purpose of this bridging is to allow the controller 100 to distinguish between, on one hand, a pressure between the high and low pressures, and on the other hand, atmospheric pressure or a pressure higher than the high pressure. Without bridging, all three conditions would result in the same output signal from the sensor.
By providing the contact bridging, only atmospheric pressure and a pressure higher than the high pressure result in the same output indication from the sensor, and the controller can determine which is the correct pressure by considering the previous pressure indication. Each time the controller 100 determines a pressure, it saves an indication of the pressure, and by comparing a previous indication with a current indication the controller can determine if the correct pressure is atmospheric or higher than the high pressure. For example, if the controller samples the sensor by applying a signal to terminal 88 , and no output signal is produced at either contact 92 or 94 , the pressure may be either atmospheric or higher than the high pressure. The previous saved indication is examined and if it indicated a high pressure then the current pressure must be higher than the high pressure, but if the saved indication indicated a low pressure then the current pressure must be atmospheric pressure.
The printhead cartridge 14 has therein an ink level sensor 98 . Sensor 98 may be a variable sensor having a capacitance which varies according to the level of ink in the foam-filled ink reservoir 12 . The controller 100 (FIG. 3) samples the sensor 98 on the order of every 100 ms and includes an analog-to-digital. converter 101 for digitizing the feedback signal from the sensor. The controller compares the digitized value with two reference values to determine when the reservoir 12 is ‘empty’, that is, when the ink level is so low that the reservoir should be refilled, or full. As subsequently explained, the feedback signal from sensor 98 is also monitored during intervals when ink should be flowing into the reservoir 12 and serves as a way for detecting when the off-board reservoir 20 is empty. Preferably, the sensor 98 is connected to controller 100 via contacts on a conventional flex circuit 99 so that the sensor feedback signal is lost if the cartridge 14 is removed from the carrier 16 . This permits detection of the removal of the cartridge during a refill operation so that ink loss may be minimized by terminating the refill operation as later described.
As shown in FIG. 3, the cartridge ink level sensor 98 , pressure sensor 26 , the drive motors for valves 22 and 24 , and bellows drive motor 30 are connected to the controller 100 . The controller may be the microprocessor which controls operation of the printer and is of conventional design. Periodically, the controller samples the level sensor 98 in the printhead cartridge 14 and when the sensor indicates that the cartridge requires refilling, the controller controls a carriage drive mechanism 102 which moves carriage 16 and the cartridge to a refill station (not shown), slides open a sliding cover 15 on the cartridge, and establishes a connection between the dispensing line 46 and the reservoir 12 , after which the controller initiates a refill operation. The drive mechanism and refill station are not shown but they may take any one of many forms known in the art. The cartridge, for example, may have an ink input opening closed by a valve as shown in the patents mentioned above, so that the sliding cover is not required.
A refill operation is initiated when controller 100 determines that the reservoir 12 is empty and the cartridge 14 is positioned at the refill station. Prior to initiation of a refill operation the system is in an initial or reset state wherein bellows drive motor 30 is off, the valve 22 is in the position shown in FIG. 4D so that line 42 is connected to the ambient atmosphere via passage 57 and the valve port 52 , and dispensing valve 24 is in the position shown in FIG. 5B so that the dispensing line 46 is connected to ambient atmosphere via passage 69 and valve port 68 . There is no ink in any of the lines or connections 32 , 42 , 44 , 46 , 60 and 64 , except for possibly a small amount of ink in the region of the T-connection 62 . The refill operation is carried out in five phases.
Phase I.
In phase I, the integrity of the system is checked to determine if there are any leaks in the ink lines 44 and 64 or their connections, or if there is no off-board supply of ink connected to the system. The controller 100 sets valve 22 to the position shown in FIG. 4B so that communication is established between line 32 and lines 60 , 44 and 64 . Next, the controller energizes motor 30 for a fixed interval of time or for a fixed number of strokes. Since valve 24 is still in the position shown in FIG. 5B, the downstream end of line 64 is blocked by the valve so that operation of bellows 28 builds up the pressure in lines 32 , 60 , 44 and 64 . The check valve 45 prevents air from entering bladder 36 during this time.
The motor 30 is energized for an interval of time T 1 , or for a fixed number of strokes of bellows 28 sufficient to raise the pressure in the lines to the high pressure. It is possible that the high pressure may be achieved even though there is a slow leak in the system. Therefore, after the interval T 1 has elapsed, the controller waits for a second interval T 2 . At the end of interval T 2 the controller samples the output of pressure sensor 26 to determine if the high pressure is still being maintained in the lines.
The intervals T 1 and T 2 will vary depending on such factors as bellows volume and stroke length and the internal volume of the portion of the system being tested.
If the high pressure is not maintained until the end of interval T 2 , there must be a leak in the system. The controller 100 terminates the refill operation and sets a visual or audible indicator 104 (FIG. 3) to signal that service intervention is required. On the other hand, if the system is still at the high pressure the controller advances to phase II of the refill operation.
Phase II.
This phase releases the high pressure used to test the integrity of the ink lines and their connections. The phase is initiated when the controller sets valve 22 to the position shown in FIG. 4 A. This connects lines 60 , 44 and 64 to atmosphere through passage 55 and valve port 55 thus releasing the high pressure in these lines. At the same time, air under the high pressure is trapped in line 32 .
Next the controller moves valve 22 to the position shown in FIG. 4C thereby connecting the interior of shell 34 to line 32 via line 42 and passage 55 in the valve. This releases the air under high pressure trapped in line 32 . Because the free air volume of shell 34 is much greater than the volume of line 32 , the pressure in line 32 drops to some value which is insignificantly above atmospheric pressure.
Phase III.
This phase tests the ability of the system to maintain the low pressure level necessary for causing the feeding of ink from reservoir 20 to the dispensing line 46 . Controller 100 energizes pump drive motor 30 and begins monitoring the pressure by sampling pressure sensor 26 . The pump motor is energized for an interval of time T 3 or until the sensor indicates that the low pressure has been reached, whichever comes first. The air displacement (pump motor on time or number of pump strokes) required to reach the low pressure level is saved in a memory in controller 100 as an indication of the ink level in the off-board reservoir 20 . If the minimum air displacement is required, the reservoir 20 is full but if the maximum air displacement is required the reservoir is empty or almost empty. A value somewhere between the maximum and minimum can be used to infer, by interpolation, the current ink level or capacity of the reservoir 20 .
The controller 100 repetitively samples sensor 26 while the pump motor is energized. If the pressure in line 32 reaches the desired pressure within the interval T 3 then a check is made for a slow leak in the air line 42 and its connections. The energizing of the pump motor and the sampling of the pressure sensor are terminated either when the pressure in line 32 reaches the low pressure or when the interval T 3 has elapsed. Then, after an interval T 4 the pressure sensor is again sampled. If the line 32 is still at the low pressure, it means that there is no leak and phase IV of the refill operation is initiated.
If, at the end of interval T 4 , the pressure in line 32 has dropped below the low level, it means that there is a leak in line 42 or its connections. The indicator 104 is energized to signal that operator intervention is required and the refill operation is aborted by jumping to Phase V described below.
If the pressure in line 32 never reaches the low pressure during the interval T 3 , it probably means that reservoir 20 is not installed. The refill operation is aborted by jumping to Phase V and an indicator is energized to signal the operator. This indicator may be the indicator 104 but preferably it is a different indicator 106 so the operator may immediately discern the problem.
Phase IV.
The actual refill or transfer of ink from off-board reservoir 20 to printhead cartridge reservoir 12 takes place during phase IV. Dispensing valve 24 is set to the position shown in FIG. 5A so that the dispensing line 46 communicates with ink line 64 through passage 71 and valve port 70 . Control valve 22 was set to the position shown in FIG. 4C during phase III and is still in that position so as soon as valve 24 is set, the low pressure in lines 32 and 42 and in shell 34 forces ink from bladder 36 so that it flows through lines 44 and 64 , valve 24 and line 46 to the cartridge reservoir 12 .
As the ink flows from the bladder, the pressure in lines 32 and 42 and shell 34 gradually drops. The controller 100 periodically samples the pressure sensor 26 during phase IV and, when the sensor produces an indication that the pressure has dropped below the low pressure, the controller energizes pump motor 30 to bring the system back to the low pressure level. Referring to FIG. 2, the pump is energized when contact surface 90 moves below contact 92 and the energizing continues until the contact surface 90 has been moved counterclockwise to bridge between contact 92 and the lower edge of contact 94 .
The refill operation continues for a fixed interval of time T 5 or until the level sensor 98 indicates to the controller 100 that the cartridge reservoir 12 is full.
The interval T 5 is the time it should take to refill an empty cartridge if the refill system is operating normally and there is no leakage or blockage of the ink flow path.
During the interval T 5 the controller 100 repetitively samples the level sensor 98 which should indicate rising levels of ink in cartridge reservoir 12 if ink is flowing from the off-board reservoir 20 into the cartridge reservoir. If the sampling of sensor 98 does not indicate a rising ink level in reservoir 12 and if the air displacement required to bring the system to the low pressure during Phase III exceeded a threshold value (indicating a low level of ink in reservoir 20 ) the controller sets indicator 106 to signal an operator that the off-board reservoir 20 is empty. In this case printing may be continued until the ink in cartridge reservoir 12 is exhausted. On the other hand, if the sampling of level sensor 98 does not indicate a rising ink level in reservoir 12 but the air displacement required to bring the system to the low pressure during Phase III did not exceed the threshold value (indicating an adequate level of ink in reservoir 20 ) indicator 104 is turned on to signal that operator intervention or a service call is required.
As previously stated, the pump 18 is intermittently actuated during Phase 4 to bring the system pressure back to the low level. During the entire Phase 4 the time between pump actuations and the time (or number of actuations) required to return the system to the low pressure level are closely monitored by controller 100 . If pressure is lost too soon or if it takes too long to bring the system back to the low pressure level, the ink is flowing at an unusually high rate. This indicates a leak. Indicator 104 is actuated to signal that operator intervention is required, Phase IV is terminated and Phase V is initiated.
On the other hand, if the pressure drops too slowly the ink is flowing at too slow a rate. This indicates a blockage. Again, indicator 104 is actuated, Phase IV is terminated and Phase V is initiated.
Phase V.
Phase V is carried out after a successful refill operation or when the refill operation is aborted. During Phase V the system is depressurized and the lines are purged of ink. Control valve 22 is permitted to return to the position shown in FIG. 4D so that the pressure in reservoir 20 and line 42 is relieved by venting to the atmosphere through outlet 52 . Valve 22 is then set to the position shown in FIG. 4B so that line 32 communicates with line 60 through passage 57 . Pump 18 is energized for a fixed interval of time sufficient to drive ink in lines 60 and 64 through dispensing valve 24 , fill tube 46 and into the cartridge reservoir 12 . Pump 18 is then stopped and control valve 22 is returned to the position shown in FIG. 4A thereby relieving the pressure in lines 44 , 46 , 60 and 64 and valve 24 . Finally, dispensing valve 24 is permitted to return to the position shown in FIG. 5B so that line 46 is open to the atmosphere through port 68 and ink in the fill tube drains into the cartridge reservoir.
A small volume of ink remains in line 44 until the next refill operation. This volume may be adjusted or selected by proper selection of the length and/or diameter of line 44 . An adequate volume must exist such that the ink remains in a fluid state after air trapped in lines 60 and 64 becomes saturated with water vapor from the ink trapped in line 44 . If the ink volume in line 44 is at least 1% of the air volume in lines 60 and 64 , less than 1% of the water in the trapped ink will be lost as water vapor.
The invention may be adapted for use in color printers having three ink supplies 20 for refilling each of three printhead cartridge reservoirs 12 with inks of different colors. The cartridge reservoirs may be contained within a single cartridge or each reservoir may be in a different cartridge. If more than one printhead cartridge is used, the apparatus described above may be duplicated for each cartridge, or another multiport valve, similar to control valve 22 , may be provided between the pressure detector 26 and the existing control valve 22 , allowing use of a single pump and pressure detector for all cartridges.
If plural reservoirs are provided in a single cartridge, the control valve 22 must have an additional output for each reservoir and the dispensing valve 24 must have an additional output for each cartridge reservoir.
From the foregoing description it is evident that the ink supply system of the present invention provides many advantages over the prior art. Prior to each cartridge refill operation the system is checked for leaks using air rather than ink, thus reducing ink loss if there is a leak in the system. Because the system is tested at high pressure relative to its operating pressure, potential causes of ink leakage may be detected before actual ink loss occurs. In the event of a leak the source of the leak may be determined with air by turning the system on one or more times while examining lines, connections, etc. This avoids the necessity of repeating an earlier failing condition with its attendant loss of ink.
If electrical power is lost during a refill operation, the system automatically returns to the initial state. The bias on the handle of valve 22 returns the valve to the position shown in FIG. 4D so that the pressure in reservoir 20 and line 42 is relieved, and the bias on the handle of valve 24 returns this valve to the position shown in FIG. 5B so that dispensing line 46 is vented to the atmosphere to permit any ink therein to drain into cartridge reservoir 12 .
Although some ink may be lost if an ink line should break or fall off while ink is being pumped, the pumping operation is aborted within a small fraction of a second, thereby reducing ink loss, and the system is returned to its initial state. The pumping operation is also aborted to reduce ink loss if the printhead cartridge 14 is removed during a refill operation.
Finally, the ink supply system monitors the presence of the off-board reservoir and the presence of an adequate supply of ink therein, and informs an operator when the reservoir requires attention.
|
A system for intermittently refilling the cartridge reservoir in an ink jet printer from an off-board ink supply tests the ink flow path prior to initiating a refill operation. Air at a pressure greater than the ink feed pressure is applied to the ink flow path to check the integrity of the system. After venting the system to the atmosphere, a slow leak check is made by closing the system, pressurizing it at the feed pressure, turning off the pressure source and, after a short interval, checking the pressure to see if the feed pressure is being maintained. If the integrity check or the slow leak test should fail, the refill operation is aborted and an indicator is set to alert an operator that intervention is required. During the interval the system is being raised from atmospheric to feed pressure, the air displacement is measured and saved as an indication of whether the amount of ink in the off-board supply exceeds a given level. As ink is being transferred into the reservoir, the ink level in the reservoir is monitored. When the ink level does not rise, or rises too slowly, the saved air displacement is used to determine whether to abort the refill operation and indicate a system problem, or set an indicator to signal that the off-board ink supply is exhausted. A controller measures the air displacement by measuring the time, or counting the number of pump strokes, required to raise the system pressure from atmospheric to feed pressure.
| 1
|
FIELD OF THE INVENTION
This invention relates to a dazzling light device, and more particularly to a light device incorporated with lamp shades to produce a dazzling light effect.
BACKGROUND OF THE INVENTION
Light devices are well used for many years by human being to assist in walking or working at a dark area. The light device comprises a shell and a lighting element (also known as a bulb or a light emitting diode) secured within the shell. When the light device is activated, the light reflects through the reflecting surface of the shell to enhance illumination.
The traditional light devices can only provide illumination without any decorating effect to attract consumers.
Thus, the inventor has derived the present invention to provide a light device, which is attractive.
SUMMARY OF THE INVENTION
It is the primary objective of the present invention to provide a dazzling light device, which attracts people's eyesight.
It is another objective of the present invention to provide a dazzling light device, which produces a dazzling light effect.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a first embodiment of the present invention;
FIG. 2 is a cross-sectional view of a second embodiment of the present invention;
FIG. 3 is a cross-sectional view of a third embodiment of the present invention;
FIG. 4 is a cross-sectional view of a fourth embodiment of the present invention;
FIG. 5 is a cross-sectional view of a fifth embodiment of the present invention;
FIG. 6 is a cross-sectional view of a sixth embodiment of the present invention; and
FIG. 7 is a cross-sectional view of a seventh embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention comprises a shell 1 , a gem stone 2 and one or several lighting members 3 .
The shell 1 comprises a holding section 11 . (In this embodiment, the holding section 11 is consisted of a number of ribs.) The lighting member 3 is secured on the inner wall of the shell 1 .
The gem stone 2 (diamond will be taken as an example in this embodiment) is secured by the holding section 11 to stay in the shell 1 firmly, and is cut in various angle surfaces 21 . Due to the transparent character, the light will reflect or refract from various angles.
When the lighting member 3 is activated to illuminate, the gem stone 2 will reflect or refract the light from all of its cutting surfaces 21 and perform multiple reflections or refractions to produce dazzling light effect.
A second embodiment of the present invention, as shown in FIG. 2 , the lighting member 3 A is relocated in the holding section 11 of the shell 1 and behind the gem stone 2 . The lighting member 3 A will shine the bottom of the gem stone 2 , and the gem stone 2 will reflect or refract the light from all of its cutting surfaces 21 . The illumination will produce a different effect.
For the above two embodiments, the gem stone 2 may reflect or refract light from an outside light source without the requirement of lighting members 3 in the shell 1 to produce the same dazzling light effect.
A third embodiment is illustrated in FIG. 3 , which comprises other than the shell 1 A, the gem stone 2 and the lighting member 3 A, a connecting ring 4 and a first lamp shade 5 .
The shell 1 A comprises a holding section 11 A on the inner wall, a notch 12 A at the outer ridge, and a transmission device 13 A corresponding to the notch 12 A. The transmission device 13 A has a transmission wheel 131 A seating on the notch 12 A. The transmission device 13 A is best to be a motor. The shell 1 A is provided with a supporting section 14 A secured on the inner edge corresponding to the notch 12 A. The supporting section 14 A is an auxiliary wheel in this embodiment.
The connecting ring 4 comprises a gear 41 on its outer edge adapted to mesh with the transmission device 13 A, and is connected with the first lamp shade 5 at the inner edge of the connecting ring 4 . A trough 42 is formed between the inner edge and the outer edge of the connecting ring 4 .
The first lamp shade 5 is made of transparent material having a protuberance surface 51 at one side with a plurality of refracting surfaces 52 .
The first lamp shade 5 is fastened into the trough 42 of the connecting ring 4 with the gear 41 meshing with the transmission wheel 131 A of the transmission device 13 A. The connecting ring 4 is driven to rotate in relation to the gem stone 2 by the transmission wheel 131 A of the transmission device 13 A. The cutting surfaces 21 of the gem stone 2 reflect or refract the light to the refracting surfaces 52 of the protuberance surface 51 of the first lamp shade 5 to produce multiple reflections or refractions.
A fourth embodiment of the present invention, as shown in FIG. 4 , is to add a second lamp shade 6 which is mounted on a second notch 12 B of a shell 1 B, and a second transmission device 13 B is also secured to the shell 1 B with another transmission wheel 131 B extending into the second notch 12 B. The inner wall of the shell 1 B is also formed with a supporting section 14 B. The supporting section 14 B is an auxiliary wheel in this embodiment.
The second lamp shade 6 is connected to the connecting ring 4 at its outer edge. The gear 41 of the connecting ring 4 meshes with the transmission wheel 131 B of the transmission device 13 B, thus the second lamp shade 6 may be rotated with respect to the first lamp shade 5 .
To practice, the two transmission devices 13 B link the first lamp shade 5 and the second lamp shade 6 to rotate in an opposing direction.
A fifth embodiment of the present invention, as shown in FIG. 5 , comprises a shell 1 C having a sliding trough 12 C. The shell 1 C is provided with a transmission device 13 C at its outer edge. The transmission device 13 C comprises a leading screw as its spindle. The connecting ring 4 A connected with the first lamp shade 5 has a sleeve 41 A extending from its outer edge. The sleeve 41 A is formed with inner threads therein. The connecting ring 4 A extends outwardly from the sliding trough 12 C to connect with the spindle of the transmission device 13 C, while the connecting ring 4 A is formed with at least one pivoting hole 42 A at its outer edge in relation to the sleeve 41 A for insertion of a guiding rod 15 pivotally connected to the inner wall of the shell 1 C.
When the spindle of the transmission device 13 C rotates, the connecting ring 4 A links the sleeve 41 A and the first lamp shade 5 to slide along the guiding rod 15 in a linear direction in relation to the gem stone 2 . This distance change will produce a different lighting effect as well.
A sixth embodiment, as shown in FIG. 6 , other than fifth embodiment is to add a unit of a second lamp shade 6 and a second connecting ring 4 A to the shell 1 C. The second lamp shade 6 and the second connecting ring 4 A are driven by the transmission device 13 C. Each connecting ring 4 A is provided with the sleeve 41 A and the pivoting hole ( 42 A) to receive the spindle of the transmission device 13 C and the guiding rod ( 15 ) therein.
In practice, when the transmission device 13 C is activated, the first lamp shade 5 and the second lamp shade 6 are linked to move in a linear direction in relation to the gem stone 2 . This makes the light provide an even dazzling effect. The first lamp shade 5 and the second lamp shade 6 of this embodiment are linked by the transmission device 13 C to move closer or farther in an opposite direction.
A seventh embodiment of the present invention as shown in FIG. 7 , comprises a shell 1 D. The shell 1 D is consisted of a first shell 11 D and a second shell 12 D. Both the first shell 11 D and the second shell 12 D comprise reflecting surfaces 111 D and 112 D at the inner walls, respectively. The shell 11 D further comprises a shade 7 with a protuberance surface 71 thereon. The protuberance surface 71 has a plurality of refracting surfaces 72 . When the lighting member 3 A shines the gem stone 2 , the light reflects or refracts from the gem stone 2 to the reflecting surfaces 111 D and 112 D of the first shell 11 D and the second shell 12 D and makes multiple reflections of the light through the reflecting surfaces 111 D and 112 D before the light goes to the shade 7 which makes another reflection and refraction through the refracting surfaces 72 .
|
A dazzling light device includes a shell, a gem stone and one or several lighting members. The shell comprises a holding section to hold the gem stone therein. The lighting member shines light to the gem stone which then refracts or reflects light from various angles to produce dazzling light. By rotating or moving lamp shades in relation to the gem stone, the light produces different dazzling effect.
| 5
|
FIELD OF THE INVENTION
This invention relates to automoated machines for supplying molded plastic six-pack or eight-pack carriers to upstanding necked containers such as bottles, to form a carrying assembly for hand transport of the carriers with the bottles held by their necks after the molded plastic article is pressed over the bottle caps. More particularly, the present invention is directed to a machine or apparatus which functions automatically and without the necessity for complex and intricate synchronizing means to assure proper positioning and assembly of the carriers relative to the individual bottles.
BACKGROUND OF THE INVENTION
In current use today to facilitate packaging and transport of a plurality of containers such as bottles, cans and the like, are molded plastic container carriers of modified sheet form which bear a plurality of openings through which portions of the bottles or can protrude such that they are frictionally gripped. In the case of bottles, the carriers are provided with spaced holes or openings generally sized to the necks of the bottles and being stretched or otherwise deformed locally to permit the carriers to move downward onto the bottlenecks such that the bottle caps and the upper portions of the necks protrude through the holes with carrier portions at the necks frictionally gripping the bottles beneath the enlarged caps.
Various machines or production apparatus have been devised for automatically effecting the assembly of the carriers to a grouped number of bottles to form an easily transportable, hand carried package. One such machine forms the subject matter of U.S. Pat. No. 3,967,807 to Eugene F. Doucette issuing Feb. 25, 1975. The applicator machine of that patent is highly complex and fully automated, requiring synchronous movement of many different parts. A plurality of stacks of nested carriers are arranged on a turret. The turret is rotated to place the individual stacks, one at a time as needed directly overlying a hopper. The nested stacks are then released into the hopper where they are frictionally maintained and prevented from discharging through the bottom of the hopper. A plurality of worm gears constitute drive mechanisms to pull off the carriers, one at a time in a continuous fashion, and drop them onto an inclined carrier delivery conveyor belt. A gating mechanism at the bottom, exit end of the conveyor belt holds the carriers in a position such that its lead end extends downstream of the conveyor and in the path of movement of the tops of the bottle containers as they are transported on a horizontally oriented endless conveyor mechanism. The bottle containers are brought to a first assembly station by means of a container conveyor belt, and, at that station, the containers come into contact with a first pair of star wheels. The star wheels are positioned on opposite sides of the conveyor belt and operate to position the containers substantially perfectly so as to fit the indentations on the carriers. The exit end of the carrier conveyor is also at this assembly station such that, as the bottles move along the conveyor, the tops of the bottles grab the front end of the carrier presently at the exit of the carrier conveyor and pull the entire carrier out of the gate, whereby it is properly fitted to the tops of six or eight bottles, depending upon whether the machine is arranged for forming six-packs or eight-packs.
Thereafter, the containers with the carrier riding on the tops of the bottles pass to a final assembly station, which includes an applicator wheel. The application wheel is provided with indentations on its periphery at positions corresponding to the tops of the containers which pass beneath the wheel which is rotated about a horizontal axis and which overlies the containers and the carrier. The wheel is pivotably mounted and biased downwardly so as not to crush the bottles in case there is misregistration between the indented portions of the application wheel and the tops of the containers.
A second pair of star wheels insure alignment of the bottle containers at the final assembly station with the indented portions of the application wheel. The star wheels are positioned just below and slightly in advance of the application wheel. As the bottles carrying the carrier pass beneath the application wheel, the wheel forces the carrier downwardly, and the bottle tops are projected through small diameter openings within the carrier, such that the carrier grips the necks of the bottles just below the bottle caps.
While the machine of the referred to patent operates adequately to place the molded carrier onto the multiple bottles to create carrying packages in six-pack or eight-pack form, the machine is highly complicated due to the necessity for synchronously moving the bottles and the carrier and for insuring that synchronism, once initiated, continues throughout the various stations of the machine.
It is therefore a primary object of the present invention to provide an improved simplified and low cost carrier applicator for bottle containers, in which there is no necessity to synchronously drive the bottles, the carrier or the applicator wheel, and in which any synchronization to effect container and carrier assembly is achieved by the components themselves.
SUMMARY OF THE INVENTION
The present invention comprises an improvement in a machine which forcibly applies the series of molded plastic carriers having rows of aligned holes therein onto a series of upright container bottle moving along a horizontal bottle path. The machine includes a hopper which supports at least one stack of carriers above the bottle path and means for removing in serial fashion the carriers from the bottom of the stack and feeding them along a corresponding carrier path leading from the carrier stack towards the underlying bottle movement path and intersecting the same. The movement of the bottles causes the tops of the bottles to pull the carriers over and across the tops of the bottles passing thereunder. An applicator wheel is mounted for rotation about a horizontal axis, positioned above the bottles and the carrier and downstream of the intersection of the carrier and bottle paths. Means are provided for forcibly applying the wheel into peripheral contact with the carriers to press the carriers onto the bottles to the extent that the bottle tops project through the holes to form six-pack or eight-pack assemblies.
The improvement resides in employing a gravity chute which is longitudinally aligned with the bottle path and is inclinded downwardly and away from the at least one carrier stack and terminates in an open discharge end just above the top of the bottle moving along the bottle path. The bottle path is formed by a horizontal powered conveyor means positioned beneath the chute with its discharge end terminating upstream of the discharge end of the gravity chute and having a table whose top is aligned with the horizontal powered conveyor means and which extends downstream therefrom from the discharge end of the horizontal powered conveyor means to a point underlying the applicator wheel. Further, individual open top cartons of predetermined size carry a predetermined number of upright bottles in row and column positions within the cartons corresponding to the position and spacing of the holes within the carriers such that regardless of random movement of the cartons of bottles along the horizontal bottle path as determined by the horizontal powered conveyor means, the cartons are moved over the table beneath the discharge end of the chute and to the applicator wheel in end to end contact solely by the force of cartons discharging onto the table top from the powered conveyor means, such that carriers are always in proper alignment with the upright bottles. Thus, multi-bottle carrier packs are readily assembled with the carrier portions encircling the bottle necks and with the carriers embracing a selected group of container bottles.
The applicator wheel preferably comprises a hollow drum having an open peripheral network including circumferentially spaced members contacting portions of the carriers on opposite sides of given carrier holes. These members may comprise a plurality of transversely extending parallel rods joined to respective discs at opposite ends and forming said open network. Further, longitudinally spaced rubber bands may resiliently encircle the plurality of rods and be laterally spaced in conformance to the rows of holes on the carriers to effect pressing contact by the drum on the carriers at both longitudinal and lateral opposed sides of the carrier holes.
At least one taper plate may be fixedly cantilever mounted adjacent to the discharge end of the gravity chute and extend at a slight downward inclination in the direction of movement of the carriers, the bottles and the cartons with the taper plate having a leading end positioned above the carriers and a trailing end in slight pressing contact with the leading end of the carriers as they discharge onto the top of the bottles to facilitate proper disposition of the carriers onto the bottles. Preferably, the hopper includes transverse side by side duplicate carrier stacking compartments, a pair of oscillating vacuum cups selectively subjected to vacuum pressure are movable into and out of the carrier stack compartments and forcibly remove the lowermost carriers from the stack and place onto the chute bottom wall to form a series of end to end abutting carriers gravity fed to the discharge end of the chute. A cam operated vacuum pressure relief operatively driven by the shaft bearing the vacuum cup arms acts to interrupt the application of vacuum pressure to the vacuum cups at the moment the cups move the lowermost carriers of the stack into contact with the supply end of the chute to assure the serial feed of carriers to the area of intersection of the carrier path and the bottle path.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a simplified self-synchronizing bottle applicator machine of the present invention forming one embodiment of the present invention.
FIG. 2 is a top plan view of a portion of the machine of FIG. 1, showing the carrier hopper and the carrier gravity chute.
FIG. 3 is an enlarged, vertical sectional view of a portion of the machine shown in FIG. 2 taken about line 3--3, as seen from the side opposite that of FIG. 1.
FIG. 4 is a vertical sectional view of a portion of the machine shown in FIG. 2 taken about line 4--4.
FIG. 5 is an exploded perspective view of the carrier hopper and the supply end of the carrier gravity chute of the machine of FIG. 1.
FIG. 8 is an enlarged, top plan view of the portion of the machine shown in FIG. 1 bearing the applicator wheel.
FIG. 6 is an enlarged, side elevational view of a portion of the machine shown in FIG. 8, partially in section and partially broken away.
FIG. 7 is a front elevational view of the machine of FIG. 1.
FIG. 9 is a perspective view of a carton of 24 bottle containers in four six-pack groups bearing carriers with the forward two of the carriers pressed onto the necks of the bottles by the applicator wheel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, there is shown generally at 10 an applicator machine or apparatus forming a preferred embodiment of the present invention, the machine functioning to dispense six or eight-pack bottle carriers 14 from a stack and apply the carriers 14 to bottles 16 carried within open top cartons 30 and with the carriers and bottles moving along intersecting paths. The machine indicated at 10 comprises, in terms of major parts, a frame indicated generally at 12 including a table 18 with the top 18a of the table being aligned with the upper run of an endless conveyor belt 22, at its discharge end 22a. The belt 22 is driven by a suitable drive mechanism indicated generally at 20. A hopper 24 is frame mounted at the rear of the machine and is integral at its lower end with an inclined, carrier gravity chute 26 whose discharge end 26a overlies and is somewhat spaced vertically from the top 18a of table 18. At the discharge end of the table 18, remote from belt 22 there is provided an applicator wheel 28 which functions to press the individual carriers 14 downward over the tops of the bottles 16 at this point in the movement of the bottles which are confined within cartons 30. The bottles 16 are borne in the individual cartons 30 as best seen in FIG. 9, the carton 30 moving from left to right in FIG. 1 on the upper run of the conveyor belt 22 and discharging onto the front end of table 18. As indicated in FIG. 9, each carton 30 is of standard size, being open at its top and bearing twenty-four bottles in this case. This permits the creation of four six-packs by applying four carriers 14 to the bottles 16. In that respect the bottles 16 are aligned four abreast in six longitudinal rows from the front end 30a of the carton to the rear end 30b of that carton. The bottles 16 are provided with closures or caps as at 32 and the bottles 16 and are of the necked variety including necks 16a which threadably or otherwise bear the caps 32. The carriers 14, which are illustrative only of one form which these articles can take, are of molded plastic sheet material including a flat center portion as at 14a and an integral tapered skirt 14b about the complete periphery. The flat central portion 14a is perforated as at 34 in two laterally spaced, longitudinal rows of three holes each, the holes taking a form of star cut outs defining radially inwardly projecting lips 36 which are spaced diametrically from each other a distance which is smaller than the diameter of the bottle caps 32. Thus, the lips 36 are deformed when the carriers are pressed downwardly to the extent that the caps 32 borne by the necks 16a project through the holes 34. This is seen in FIG. 9 as the transition from the position shown for the carriers 14 with respect to the last three transverse rows of bottles in contrast to the first three adjacent the leading end 30a of the carton 30. Further, hand gripping holes 38 may be provided within the carrier to assist lifting of each completed carrier and bottle assembly or carrying package for removal from the carton.
An important aspect of the present invention is the utilization of the endless conveyor belt 22 and the cartons 30 for advancing the bottles to the carrier applying station at the right hand end of the machine, FIG. 1. Further, it is additionally important to note that the endless conveyor belt 22 does not extend the full length of the machine but terminates at some distance upstream of the discharge end 26a of the carrier gravity chute 26. In that respect, as seen in FIG. 6, the table 18 bears a plurality of elongated rollers 40 which rotate about axles 42 which axels span between laterally opposed C beams 44 to define the table top 18a. The cartons 30 bearing the bottles 16 are thus caused to move by force application, from one carton to another, created by the cartons 30 discharging from the right hand end 22a of the conveyor belt 22. Regardless of how the cartons 30 are spaced on the endless conveyor belt 22, the dead space created by the termination of the endless conveyor belt 22 upstream of the discharge end 26a of the gravity chute insures that the cartons 30 downstream of the conveyor belt 22 will be in abutment with each other, and therefore not only will the cartons 30 be aligned, but the aligned bottles carried by the cartons 30, correspond to the end to end abutting line of carriers 14 being fed to the area of intersection of the bottle and carrier paths.
Frame 12 is made up of a series of laterally spaced columns 46 which, in addition to support table 18 at the right hand end at the front of the machine. Certain of the multiple columns 46 are connected to longitudinal beams 48 to form a framework to support the endless conveyor belt 22 for rotation in a clockwise direction, FIG. 1. Cartons 30 which are loaded onto the rear of the machine, that is, at the left, FIG. 1, onto the top run of the conveyor belt 22, move towards the discharge end 22a of the belt 26 adjacent table 18. The conveyor drive mechanism 20 comprises a conveyor drive motor 52, a transmission mechanism 54, and chain drive element 45, all supported by the frame 12. This assembly drives the conveyor belt 22 at a desired speed. There is no necessity to correlate the speed of the conveyor belt 22 to any of the other driven elements of the machine. The columns 46 at the rear of the machine act to support at a vertical height well above table 18, the hopper 24 and the supply end of the gravity chute 26. In that respect, frame 12 includes a set of first horizontal beams or bars 60, FIG. 3, intermediate of the conveyor belt 22 and the upper ends of left end columns 46, and second set of horizontal beams or bars 62 at the extreme upper ends of those columns 46. These members define a support platform for the components associated with the hopper and the upper end of the gravity chute 26. The frame members as well as the other major components of the machine may be formed of metal and may be welded to each each other to form a rigid assembly. The chute 26 is formed of sheet metal including laterally opposed sidewalls as at 64 an integral bottom wall 66 and bears a plurality of doors as at 68 hinged to one of the sidewalls 64 by suitable hinges as at 70, FIG. 2. This permits access to the interior of the chute 26 should the individual carriers as at 14 become stuck and fail to slide by gravity down the upper surface of bottom wall 66 as seen in FIG. 3.
Further, the hopper 24 is integrally joined to the upper end 26b of the chute 26. The sheet metal hopper includes oppposed vertical sidewalls 72, a rear wall 74 which spans therebetween and a front wall 76 of reduced height. Further, the hopper 24 acts to support two stacks of carriers 14 within individual stacking compartments as at 78 and 80, the compartments being separated by a central vertical separating wall 82. The bottom of the hopper 24 opens to the bottom wall 66 of the gravity chute 26. Further, there is provided a vertical separating wall 82 within the chute 26 and which extends the full length of the same so as to maintain separate carrier paths for the carriers 14 as they slide down chute 26 after being dispensed from respective carrier stacks within hopper compartments 78 and 80. The sidewalls 72 of the hopper 24 are of generally modified L-shaped configuration and being wider at the bottom than they are at the top. Further, the rear wall 74 bears rectangular openings or slots as at 86 for each compartment which are aligned with elongated rectangular openings or slots 88 within the bottom wall 66 of the chute 26. The purpose of these openings is to permit a pair of suction cups as at 90, FIG. 3, to penetrate into respective compartments interiors and to contact the bottom of the lowermost carriers 14 of respective stacks and to pull the lowermost carriers downwardly to a position where they contact the bottom wall 66 of the chute. The suction is terminated for cups 90 and the cups are separated from the carriers. The carriers 14 are permitted to slide by gravity down the chute in two separate parallel rows, end to end, for the discharge serially at the discharge end 26a of the gravity chute. The front wall 76 of the hopper bears a rectangular opening 89 within its lower end to permit access to the interior of the cute at this point should the need arise.
The carriers in nested fashion form two separate stacks within respective compartments 78 and 80 as seen in FIG. 3, with one edge of the lowermost carrier 14 contacting the upper end of the bottom wall 66 of the conveyor chute 26, FIG. 3. The carriers in nested fashion are frictionally restrained and prevented from falling onto the bottom wall 66 of the conveyor by means of spring friction plates 94 forming a portion basket tension adjustors 95, the spring friction plates being fixed at their upper ends as at 94a to the rear of hopper front wall 76.
The spring friction members 94 are cantilevered with their free ends 94b pressed against the edges of the stacked carriers, at the bottom of the stack, which face the front wall 76 of the hopper. Sufficient frictional force is maintained to prevent inadvertent gravity drop. Adjustment screws 96 are screws threaded to the front wall 76 and project therethrough so that by rotating the screws, the spring friction plates 94 are compressed to a greater degree against the edge of lowermost carriers of the stacks when the two stacks are loaded in the manner of FIG. 3.
As noted previously, the supply end 26b of the chute overlies a rectangular opening 98 defined by the transversely spaced bars or beams 62, FIG. 2. A shaft 100 straddles, transversely, opposed beams 62 and is mounted for rotation about its axis by means of bearing blocks 102 at each end. The blocks 102 are fixed to opposite bars or beams 62 and the shaft 100 is thus rotatable about its axis. Vacuum cup arms 104 are fixed to the shaft 100 at longitudinally spaced positions aligned with openings 88 and 86. The arms bear at their outboard ends the vacuum cups 90 to which vacuum pressure is selectively supplied by way of tubing or hose 106. A crank mechanism indicated generally at 108 includes a link 110 attached at one end to a short length crank arm 112 fixed to shaft 100 and at its other end to a second crank arm 114. Crank arm 114 is fixed to and projects radially from one end of shaft 116. Rotation of shaft 116 about its axis, cause the oscillation of the vacuum cup arms 104 between position wherein the vacuum cups 90 contact the lowermost carriers 14 to a position where the lowermost carriers are transferred into full surface contact with the bottom wall 66 of chute 26 adjacent its upper end.
Shaft 116 is supported appropriately by paired bearing blocks 117, beneath the transverse frame bars or beams 62, the bearing blocks 117 being mounted on one of the beams 62 and a short length beam 62a, respectively. The shaft 116 is driven by means of an air drive motor 118 which is mounted to the short length beam 62a. It drives the shaft 116 through a chain and sprocket drive mechanism 120. Mounted to a plate 124 supported in turn by the intermediate beams or bars 60 of the frame member 12 is a combined air compressor and vacuum pump indicated at 126. This is the source of vacuum pressure for the paired vacuum cups 90 through their supply lines 106. Further, positive air pressure from the combined compressor/vacuum pump 126 is supplied to the air motor 118 through its supply line 128. Lines 106 which lead from the vacuum source portion of the compressor/vacuum pump unit 126 normally permit vacuum pressure to exist at all times within the vacuum cups 90. However, to effect the timed release of the carriers from the stacks within compartments 78 and 80 of the hopper 24, there is provided a vacuum release mechanism indicated generally 130. This mechanism is best seen in FIG. 4. The mechanism consists of a metal strip 132 of rectangular configuration being pivotably mounted to bar 62 at one end as by way of screw 134. The opposite end, which extends just beyond shaft 100, carries an elongated slot 136 at right angles to its longitudinal axis, through which passes an adjustment screw 138, screw 138 being screwed into bar 62 and acting to lock the strip 132 in a desired angular orientation with respect to bar 62 and at a predetermined distance from the axis of rotation of shaft 100. The strip 132 bears a rocker arm as at 140 which is pivoted near its center by way of a screw 142. A blocker 144 mounted to the side of strip 132 bears a compression spring 146 on one face thereof, the compression spring 146 abutting the lower surface 140 of the rocker arm 140 beneath shaft 100. A portion 148 of the upper surface of the rocker arm 140 acts as a cam follower face and is in contact with the periphery of a cam 150 carried by the shaft 100 and being rotatable therewith. A cam radial protrusion 152 is borne by the cam at one circumferential position, and the cam 150 is mounted relative to the shaft 100 such that during the oscillation of the vacuum cup arms 104, at a predetermined angular position of those arm 104 and the cups 90 carried thereby, as for instance when the cups 90 pass downward to the point where they are just above or in line with the openings 88 within the bottom wall 66 of the chute 26, the radial projection 152 of cam 150 presses on the cam follower face 148 of the rocker arm 140 to cause the rocker arm, FIG. 4 to pivot counterclockwise. A vacuum relief valve indicated generally at 153 is mounted beneath the right end of the rocker arm 140, the valve comprising a valve body 154 bearing an air passage 156 which is normally closed off by a movable valve member 158 which acts to seat upon the open end of the passage 156 within the valve body 154. A vacuum line 160 leads to the valve body 154 from the vacuum pressure side of the compressor/vacuum pump unit 126. Momentarily when the rocker arm 140 is rotated counterclockwise against the bias of the compression spring 146, the movable valve member 158 moves away from the valve such to release the vacuum pressure within line 160 from the source which is also common to the vacuum cups via their lines 106.
From the above, it may be seen, therefore, that manually stacks of carriers 14 are provided within the respective compartments 70 and 80 of the hopper 24. The lowermost carriers 14 are prevented from dropping out of the hopper onto the upper end of the chute 26. However, the vacuum pressure applied by way of cups 90 overcomes the frictional restraint provided by the tension or frictional force exerted on the edges of the carrier and permits the applied suction force to pull off the lowermost carriers 14 and deposit them on the upper face of the bottom wall 66 of the chute, with vacuum cut off occurring at the moment of contact of the bottom wall of the chute by the lowermost carrier of each of the stacks, by way of the vacuum release valve 153.
Turning next particularly to FIGS. 6, 7 and 8, the make up of right hand end or front of the machine, FIG. 1, and the operation of the elements carried thereby may be readily appreciated. As cartons 30 of bottles 26 pass under the discharge end 26a of the gravity chute 26, the bottles 16 tend to pull in succeeding order the carriers 14 from the cute 26 on each side of the vertical divider wall 84 of that chute. Proper vertical height of the discharge end 26a of the chute 26 is important. Also adjustment of that height may be required, depending upon the height of the bottle containers 16 to be packaged. In that respect, the frame column members 46 adjacent the discharge end 26a of the chute 26 bear on opposite sides of the machine vertical adjustment strips 170, these strips 170 being slotted longitudinally at 171 through which slot 171 project adjustment screws 172 for each of the strips permitting the strips to be raised or lowered and fixed at adjustable vertical positions on the columns 46. The strips 170 bear between them a transverse shaft or rod 174. The rod 174 in turn bears arms 176 which are pivotably attached, at their lower ends, to respective opposed sidewalls 64 of the chute 26. Thus, the discharge end 26a of the chute 26 may be raised or lowered and locked at a vertical adjustable position to insure that the carrier properly fall onto the bottles 16 when the top of the leading bottle catches the skirt of the projecting portion of the carrier 14.
Further, to insure that a single carrier is gravity deposited on the tops of the bottles 16, there is provided keeper plates 180 which are cantilever mounted and being slightly inclined to the horizontal. They are fixed between the vertical columns 46 at the discharge end 16a of the chute 26, just downstream from the point of discharge. The plates 180 extend from and are fixed via a transverse rod 188 to paired vertical adjusting strips 182 which include elongated slots at 184 and through which pass adjustment screws 186. The plates 182 are carried on the inside walls of given columns 46 on opposite sides of the machine. There are individual keeper plates 180 for each of the two flow paths for the carriers 14 lying on opposite sides of the vertical dividing wall 84 of chute 26. The inclined plates 180 terminate in curved ends 180a which are fixed to transverse shaft 188 which is coupled at its ends to the opposed adjustment strips 182. The screws 186 which are threaded to the vertical columns 46 on opposite sides may be loosened and the keeper plates 180 may be adjusted vertically so that the leading edge 180b is above the top of the carrier 14 as it exits from chute 26. The trailing edge 180b should be located in the path of carrier 14 to apply light pressure to the carriers 14 at the point where they pass beneath the edge of this member. This insures that only one carrier 14 is placed on the bottles 16 at a time and holds the carriers in place when they are on the bottles as they move into contact with the applicator wheel 28 downstream from the trailing edge 180b.
The applicator wheel 28 takes the form of a hollow drum consisting of laterally opposed discs 190 being joined at the disc periphery by parallel circumferentially spaced rods as at 192. The ends of the rods 192 pass through drilled holes or the like within discs 190. The rods form an open peripheral network. The wheel 28 is mounted for rotation about its axis by means of a shaft 194 which projects through sleeve bearings 196 which are borne by bearing blocks 198 fixed on the outboard ends of a pair of applicator wheel support arms 200. Each arm 200 is pivotably mounted at its inboard end to given columns 46 at their upper ends, FIGS. 6, 7. Bolts 202 project through the arms 200 and mounting plates 204 which may be welded to the sides of the columns 46 and which project horizontally outwardly therefrom and at right angles thereto.
Further, to one side of the machine, there is further fixed a lower beam as at 206 which is welded at one end to a given column 46 and which projects horizontally at right angles to the axis of the column 46 parallel one of the plates 204 and generally in line therewith. At the end of the bars 206 remote from the column 46 to which they are attached, the bar 206 supports a sleeve or cylinder 208 which rotatably carries one end of a wheel height adjustment rod 210, the rods 210 bearing a threaded nut 212 which is fixed as by welding, to the side of respective bars 200, the wheel height adjustment rod being threaded throughout its length as at 214 and being threaded to the nut 212. The end of the wheel height adjustment rod 210, opposite the sleeve 208 bears a handle as at 216 such that by rotation of the wheel height adjustment rod handle, the rod 210 coupled to one of the bars or arms 200, the applicator wheel 28 is raised or lowered, the arm 200 pivoting about the axes of bolt 202. Axel 194 may be spring mounted to beam 200 to permit axel shift under compressive force to prevent damage to the carriers by contact of wheel periphery.
As may be appreciated, sufficient effort is required by the applicator wheel 28 rods 192 in contact with the individual carriers 14 to force the carriers 14 at their holes over the bottle caps or closures as may be seen in the partial vertical sectional view of FIG. 6 and onto the bottle necks. The rods 192 are set at circmferentially spaced distances coinciding with the spaces between the holes through which the bottle necks and caps protrude and are appropriately spaced so that simultaneously two laterally aligned carriers 14 are pressed down over the tops of the bottles. In sequence, initially, the first pair of such carriers 14 are coupled to the bottles 16 at the front of a given carton 30 as it passes through this station, then, in succeeding fashion, the last pair of carriers 14 are joined to the remaining bottles 26 of the cartons.
To insure proper lateral position of the cartons 30 with respect to the table rollers 40, appropriate vertical guide plates as at 220 may be provided, as shown in dotted lines FIG. 7. The plates 220 are supported by means of brackets as at 222 fixed to the tops of the C bars 44 supporting the rollers 40. Preferably, the guide plates 220 are laterally adjustable on the brackets 222 so that the lateral gap between these members can be widened or narrowed, depending upon the carton and bottle dimensions.
It is believed that the nature and operation of the machine is clear from the description above. However, the simplified machine or apparatus of the present invention permits simple adjustments to correlate the operation of the several components to the speed of movement of the cartons 30 of bottles 16 through the machine as fed by the endless conveyor belt 22. Preferably, the speed of the air motor 118 should be regulated by an air regulator (not shown) to permit the speed of the movement the vacuum cup arms to be is fast enough to keep a sufficient number of carriers 14 in the chute 26 when the cartons or cases 30 are moving through at maximum speed. The wheel height adjustment rod 210 is regulated by the operation of handle 216, adjusts the pressure of the applicator wheel 28 on the carriers 14. The pressure should be only enough to snap the carriers 14 downwardly onto the bottle necks as per FIG. 6. Applied positive air pressure may be applied to carriers as they start down the chute. The invention appropriately permits adjustment of the height of the discharge end of chute 26 to overt the carriers 14 properly to the top of the bottles. The chute height at this point should be approximately 1/4 of an inch over the top of the bottles 16. The cam actuated vacuum release valve 153 permits release of the carriers by the suction cups 90 at the proper time in the hopper. Adjustment may be required during machine operation. The adjustment of the cam 150 should be such that there is no bounce by the carriers 14 when they hit the bottom wall 66 of the chute 26. Further, the vacuum cup arms may be adjusted so that the vacuum cups 90 hit the center of the carriers 14, i.e., the arms may be made adjustable axially relative to the shaft 100 with which they rotate.
Further, it is preferred that a microswitch 222 be employed near the top of chute 26, FIG. 1. Microswitch 222 senses the backup of carriers 14 to the supply end 26b of chute 26, thus acting to cut off operation of the air motor 118. Once started however, the machine operates as long as carriers 14 are supplied and the carriers 14 are removed from the gravity chute 26 automatically by the horizontal movement of the bottle filled cartons 30. Appropriately, an electrical control center as at 224, FIG. 1, may be provided for controlling the conveyor drive motor 52 and providing energization for the electrical motor driving the combined compressor/vacuum pump 126.
Further, in order to effect proper compression of the carrier down over the tops of the bottles 16 and partially down the necks of the same, heavy rubber bands 226 may be provided about the periphery of the applicator wheel 28 held by the rods 192 and spaced as desired transversely between the discs 190 forming the sides of the wheel 28. The rubber bands provide longitudinal compression force on the carriers 14 adjacent the holes 34. Care must be taken to insure that the rubber bands 226 are not aligned, however, with the holes within the carriers and the tops of the bottles to insure that the rods and bands effect proper compression of the carriers onto the bottle tops to complete a six-pack or eight-pack assembly as desired.
|
An endless horizontal conveyor discharges cartons of necked bottles onto a horizontal tabletop aligned with the endless conveyor insuring carton-to-carton movement of the bottles beneath the discharge end of a gravity chute feeding a series of bottle carriers, individually supplied to the gravity chute from a nested carrier stack onto bottles. The carriers are pulled onto the bottles by movement of the cartons and the bottles carried thereby. A keeper plate adjacent the discharge end of the gravity chute and downstream therefrom insures contact between the tops of the leading end bottles in each carton and the leading end of the carrier. Movement of the carton-contained bottles pulls the carriers from the chute and deposits the carriers in proper position overlying the tops of the bottles to form six-pack or eight-pack groups. An applicator wheel downstream of the chute discharge area for the carrier presses the carriers downwardly to force the bottle tops to penetrate through given holes into the carriers corresponding to the bottle position to cause the carriers to frictionally grip the bottle necks below the bottle caps. No positive drive synchronization is required for the carton conveyor, the means for feeding the carriers from the stack within the hopper to the gravity chute or the applicator wheel for pressing the carrier downwardly onto the bottle necks.
| 1
|
This is a continuation of application Ser. No. 10/356,740 filed Feb. 3, 2003; the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a jetting head capable of ejecting various kinds of liquid in the form of droplets for use in an ink jet printer, a display manufacturing apparatus, an electrode forming apparatus, a biochip manufacturing apparatus, etc., and more particularly, to a jetting apparatus having a plurality of flexible flat cables to be used for supplying drive signals from a head driver to a jetting head.
As a jetting apparatus having a jetting head capable of ejecting liquid in the form of a liquid droplet, for example, there has been proposed an ink jet printer in which ink droplets are ejected to record an image or the like on recording paper, an electrode forming apparatus in which an electrode material in a liquid form is ejected onto a substrate to thereby form electrodes, a biochip manufacturing apparatus in which biological samples are ejected to manufacture biochips, or a micropipette for ejecting a predetermined amount of a sample into a vessel.
For instance, in an ink jet printer employing piezoelectric elements as drive elements for ejecting ink, a plurality of piezoelectric elements, which are provided so as to correspond to a plurality of nozzles of a print head, are selectively activated, whereby ink droplets are ejected from the nozzles in accordance with the dynamic pressure generated by the respective piezoelectric elements. Dots are formed on recording paper by causing the ink droplets to adhere to the recording paper, thus effecting printing operation.
Here, the piezoelectric elements are provided so as to correspond to nozzles to be used for ejecting ink droplets. The piezoelectric elements are actuated by a drive signal supplied from a head driver mounted in the print head, thereby ejecting ink droplets.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a device and a method for driving a jetting head designed to readily retain predetermined bias voltages of respective piezoelectric elements through use of a simple, compact configuration and at low cost
In order to achieve the above object, according to the invention, there is provided a head driving device, which drives a plurality of pressure generating elements for generating pressure fluctuation in a jetted object contained in each of associated pressure chambers formed in a jetting head of a jetting apparatus to eject the jetted object from each of nozzles communicated with the associated pressure chambers, the head driving device comprising:
a head driver, which generates a drive signal which is selectively applied to at least one of the pressure generating elements to be driven; and
a bias potential provider, which selectively applies a bias potential to at least one of the pressure generating elements not to be driven.
In such a configuration, the non-actuated pressure generating elements are held at the bias potential. Accordingly, the voltage applied to both electrodes of the non-actuated pressure generating elements becomes substantially zero. Hence, power draw is reduced, and a voltage drop stemming from spontaneous discharge of the pressure generating elements becomes smaller. Hence, a power loss is diminished.
Further, occurrence of discharge due to a potential difference between pressure generating elements to be driven and pressure generating elements not to be driven is also reduced. In addition, a further increase in arrangement density of a head can be attained without involvement of an operation for providing insulation between the electrodes of the pressure generating elements.
Preferably, the bias potential is a reference potential of the drive signal.
Preferably, the bias potential provider includes a potential applier which applies the bias potential, and a charger which charges the potential applier with a drive potential of the drive signal.
Here, it is preferable that the charger includes a transistor which applies the drive potential to the potential applier, and a switcher which supplies the drive signal to a base terminal of the transistor during a time period in which the drive signal deactivates the pressure generating elements.
In such a configuration, the transistor is turned on by the supplied drive signal to charge the potential applier with the bias potential.
Here, it is further preferable that the switcher continuously supplies the drive signal before and after a jetting operation is performed.
Specifically, the drive signal is supplied to discharge the potential applier after the jetting operation is performed.
Before the jetting operation, since the potential applier is gradually charged to reach the bias potential by the continuous supply of the drive signal, there is prevented occurrence of faulty operations of respective pressure generating elements, which would otherwise be caused by a sudden increase in the potential of the ground-side electrodes before commencement of the jetting operation.
After the jetting operation, since the potential applier is gradually discharged by the continuous supply of the drive signal, there is prevented occurrence of faulty operations of the respective pressure generating elements, which would otherwise be caused by a sudden drop in the voltage of the ground-side electrodes after completion of the jetting operation.
Further, it is preferable that: the head driver is mounted on the jetting head; and the switcher is embodied by a part of a switching circuit included in the head driver which selectively applies the drive signal to the at least one pressure generating elements to be driven.
In such a configuration, the switcher is provided by utilizing a surplus unused section of an existing switching circuit of the head driver mounted on a jetting head, thereby curtailing the cost of parts. Further, a space to be used for mounting the switcher is not particularly required, thus rendering the apparatus compact.
According to the invention, there is also provided a method of driving a jetting head provided with pressure generating elements, the method comprising steps of:
generating a drive signal selectively applied to at least one of the pressure generating elements to be driven to eject jetted objects; and
applying a bias potential from a potential applier to at least one of the pressure generating elements not to be driven.
Preferably, the driving method further comprises a step of charging the potential applier with a drive potential of the drive signal.
Here, it is preferable that the charging step is performed during a time period in which the drive signal deactivates the pressure generating elements.
It is further preferable that the charging step is performed during a time period in which the drive signal deactivates the pressure generating elements.
According to the invention, there is also provided a head driving device, which drives a plurality of pressure generating elements for generating pressure fluctuation in a jetted object contained in each of associated pressure chambers formed in a jetting head of a jetting apparatus to eject the jetted object from each of nozzles communicated with the associated pressure chambers, the head driving device comprising:
a head driver, which generates a drive signal which is selectively applied to at least one of the pressure generating elements to be driven;
a bias potential provider, which applies a bias potential to respective ground-side electrodes of the pressure generating elements; and
an IC package, in which the head driver and the bias potential provider are provided.
In such a configuration, the ground-side electrodes of the pressure generating elements are held at the bias potential.
Accordingly, the voltage to be applied across both electrodes of the pressure generating elements is reduced. Therefore, power consumption is diminished, and a voltage drop stemming from spontaneous discharge of the pressure generating elements is small, thereby reducing a power loss.
Further, since the voltage to be applied to the pressure generating elements becomes relatively low, electric discharge stemming from a voltage difference between pressure generating elements to be driven and pressure generating elements not to be driven is also reduced in addition, a further increase in arrangement density of the pressure generating elements can be attained without involvement of an operation for providing insulation between the electrodes of the pressure generating elements, even when pressure generating elements eventually assume a lower withstand voltage.
Since the head driver and the bias potential provider are provided integrally within an IC package, a reduction in packing, wiring, and connection space can be attained.
Preferably, the bias potential is a reference potential of the drive signal.
In such a configuration, the voltage applied to across electrodes of the pressure generating elements becomes substantially zero. Hence, a voltage drop stemming from spontaneous discharge of the pressure generating elements becomes smaller, thereby reducing a power loss.
Preferably, the head driving device further comprising:
a capacitor, having a capacitance which is sufficiently greater than a total electrostatic capacitance of the pressure generating elements, the capacitor provided with a first terminal which is electrically connected to the ground-side electrodes and a second terminal which is grounded; and
a control resistor, which electrically connects the first terminal of the capacitor and the bias potential provider.
In such a configuration, the capacitor is charged with a bias potential output from the bias potential provider by way of the control resistor. In a case where an amplifier is provided in the bias potential provider, since the charging voltage of the capacitor is applied to the pressure generating elements, it is not necessary to provide an amplifier of a high speed operable type. A low-speed, small-capacity amplifier can be used, thereby curtailing cost of such an amplifier.
Due to the existence of the control resistor, the charging and discharged currents substantially do not flow into the amplifier of the bias potential provider, but flow into the condenser. Hence, the amount of heat dissipated by the amplifier is reduced.
Here, it is preferable that the bias potential provider charges the capacitor with a potential according to a data signal inputted to the bias potential provider, so that the charged potential is applied to the ground-side electrodes of the pressure generating elements as the bias potential.
Further, it is preferable that the bias potential provider discharges the capacitor according to a data signal inputted to the bias potential provider, so that the ground-side electrodes of the pressure generating elements are discharged.
In such a configuration, due to the existence of the control resistor, a large discharged electric current does not flow into the bias potential provider, thereby lowering the amount of heat dissipated by e.g., an amplifier of the bias potential provider.
Further, it is preferable that the data signal is inputted to the head driver to generate the drive signal.
In such a configuration, a data signal can be input from a common connection terminal of an IC package constituting the head driver and the bias potential provider. Accordingly, inputting a data signal individually to the head driver and to the bias potential provider is not required, thereby reducing the wiring and connection space.
Further, it is preferable that the head driving device further comprises a temperature detector, which detects a temperature of the jetting head. The data signal corresponds to the bias potential which is determined by the detected temperature.
Alternatively, it is preferable that the number of bits forming the data signal is less than the number of a signal inputted to the head driver to generate the drive signal.
The setting accuracy of the bias potential output from the bias potential provider may be lower than the drive signal of the head driver. In such a case, a D/A converter to be incorporated in the bias potential provider can be embodied by a more compact and less-expensive D/A converter.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein:
FIG. 1 is a block diagram showing a head driving device according to a first embodiment of the invention;
FIG. 2 is a timing chart showing operation of the head driving device to be performed at commencement of printing operation;
FIG. 3 is a timing chart showing operation of the head driving device to be performed during the course of printing operation;
FIG. 4 is a timing chart showing operation of the head driving device to be performed at the end of the printing operation;
FIG. 5 is a fragmentary circuit diagram showing an exemplary configuration of an analog switch in the head driving device;
FIG. 6 is a block diagram showing a head driving device according to a second embodiment of the invention;
FIG. 7 is a block diagram showing a head driving device according to a third embodiment of the invention;
FIG. 8 is a timing chart showing a relationship between a drive signal of a head driver and a bias voltage in the head driving device shown in FIG. 7 ;
FIG. 9 is a flowchart showing operation of the head driving device shown in FIG. 7 to be performed when the device is activated;
FIG. 10A is a timing chart showing a drive signal of the head driver of the head driving device shown in FIG. 7 ;
FIG. 10B is a timing chart showing a bias voltage of the bias potential supplier of the head driving device shown in FIG. 7 ;
FIG. 11 is a flowchart showing operation of the head driving device shown In FIG. 7 to be performed at commencement of printing operation; and
FIG. 12 is a flowchart showing operation of the head driving device shown in FIG. 7 to be performed when the device is deactivated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the invention will be described by reference to the accompanying drawings. The embodiments to be described hereinbelow are preferred specific embodiments of the invention, and hence technically-preferable limitations are imposed on the embodiments. However, the scope of the invention is not limited to the embodiments unless the following descriptions include descriptions which particularly specify the invention.
As shown in FIG. 1 , a head driving device 10 according to a first embodiment of the invention comprises: piezoelectric elements 11 provided so as to correspond to a plurality of nozzles of an ink jet printer; a head driver 12 for supplying a drive signal to electrodes 11 a of the respective piezoelectric elements 11 ; a current amplifier 13 and a switcher 14 , both being interposed between the head driver 12 and the respective piezoelectric elements 11 ; and a bias potential provider 20 for applying an intermediate potential to ground-side electrodes 11 b of the piezoelectric elements 11 .
A row of nozzles are actually provided on a per-color basis in a print head of the ink jet printer 10 , and the piezoelectric elements 11 are provided for each of the rows of nozzles.
The piezoelectric elements 11 are embodied by, e.g., elements exhibiting the piezoelectric effect and formed so as to become displaced by a voltage applied across the electrodes 11 a and 11 b.
The piezoelectric elements 11 remain charged in the vicinity of an intermediate potential Vc at all times. The piezoelectric elements 11 are arranged so as to eject ink droplets from nozzles by applying pressure to the ink stored in corresponding nozzles when performing discharging operation in accordance with a drive signal COM output from the head driver 12 .
The head driver 12 is embodied as a driver IC and generates a drive signal COM to be sent to the print head which is placed in, e.g., a main unit of the printer.
The current amplifier 13 is formed from two transistors 15 , 16 . Of the transistors, a collector of the first transistor 15 is connected to a constant voltage power sour (e.g., +42V DC power supply), and a base of the same is connected to one output terminal of the head driver 12 . Further, an emitter of the first transistor 15 is connected to an input terminal of the switcher 14 . As a result, in accordance with a signal output from the head driver 12 , a constant voltage Vcc is supplied to the piezoelectric elements 11 via the switcher 14 .
An emitter of a second transistor 16 is connected to an input terminal of the switcher 14 . A base of the second transistor 16 is connected to a second output terminal of the head driver 12 . Further, a collector of the second transistor 16 is connected to ground. As a result, in accordance with a signal output from the head driver 12 , the piezoelectric elements 11 are caused to discharge by way of the switcher 14 .
Upon receipt of a control signal, the switcher 14 is turned on at a timing at which a corresponding piezoelectric element 11 is to be activated, thereby outputting the drive signal COM to that piezoelectric element 11 .
The switcher 14 is actually formed as a so-called transmission gate for activating or deactivating the respective piezoelectric elements 11 .
The bias potential provider 20 is constituted of a capacitor 21 serving as a potential applier, and a charger 22 .
The capacitor 21 is an electrolytic capacitor. One end of the capacitor 21 is connected to the ground-side common electrodes 11 b of the piezoelectric elements 11 , and the other end of the capacitor 21 is connected to ground such that a charging voltage of the capacitor; i.e., an intermediate potential Vc, is applied to the grounded elements 11 b of the respective piezoelectric elements 11 .
The capacitance of the capacitor 21 is selected so as to assume sufficient capacitance with respect to a total amount of electrostatic capacitance of all the piezoelectric elements 11 (a total of several microfarads; e.g., approximately 1.4 μF); that is, hundreds of microfarads to thousands of microfarads, so that the stable intermediate potential can be supplied to the respective piezoelectric elements 11 . Here, a device other than a capacitor may be employed as the potential applier.
The charger 22 comprises a transistor 23 serving as a switching element; a resistor 24 ; a capacitor 25 ; and an analog switch 26 .
An emitter of the transistor 23 is connected to one end of the capacitor 21 , and a collector of the same is connected to a constant voltage power supply Vcc.
In lieu of the transistor 23 , any of various types of switching elements; for example, an FET, a thyristor, and a TRIAC, may also be employed.
The resistor 24 is connected to a point located between the emitter of the transistor 23 and the ground. The capacitor 25 is connected to a point located between the base of the transistor 23 and the ground.
Further, the analog switch 26 is connected to a point located between the base of the transistor 23 , and the emitter of the first transistor 15 and the emitter of the second transistor 16 , where the transistors 15 , 16 belong to the current amplifier 13 .
Upon receipt of an activation/deactivation control signal output from the control section of the printer main unit, the analog switch 26 is activated by, for example, a high-level control signal or deactivated by, for example, a low-level control signal.
The control signal is set so as to be brought to a high level during a non-driving period of the drive signal COM output from the head driver 12 via the current amplifier 13 ; that is, a period of an intermediate potential, and so as to be brought to a low level during a driving period of the drive signal.
The control signal is set so as to become continuously high at the commencement or end of printing operation.
The head driving device 10 of the embodiment is constructed in the manner set forth and operates in the following manner in accordance with a head driving method of the invention.
First, the operation of the head driving device 10 to be performed at start of printing operation of the ink jet printer (e.g., activation of the ink jet printer) will be described.
At the time of commencement of printing operation, the drive signal COM output from the head driver 12 via the current amplifier 13 increases gradually.
As a result, in accordance with the drive signal COM, an electric current flows from the first transistor 15 of the current amplifier 13 to the electrodes 11 a of the piezoelectric elements 11 via the switcher 14 . As indicated by solid line “a” shown in FIG. 2 , the electrodes 11 a of the piezoelectric elements 11 gradually increase in potential up to the intermediate potential Vc; e.g., after a period of 20 μsec.
At this time, as a result of activation of the analog switch 26 , the drive signal COM is applied to the base of the transistor 23 of the charger 22 , thereby activating the transistor 23 .
As a result, a constant voltage output from the constant voltage power supply Vcc is applied to the capacitor 21 , thereby gradually charging the capacitor 21 . Accordingly, a charging voltage of the capacitor 21 gradually increases up to the intermediate potential Vc. As indicated by dashed lines “b” shown in FIG. 2 , the ground-side electrodes 11 b of the piezoelectric elements 11 also gradually increase in potential, thus reaching the intermediate potential Vc.
In this way, the ground-side electrodes 11 b of the piezoelectric elements 11 reach the intermediate potential in the same manner as do the electrodes 11 a to be activated by the drive signal COM. Hence, a potential difference between the electrodes 11 a , 11 b of the piezoelectric elements is suppressed to a low level. Accordingly, since the potential difference is lower than the intermediate potential Vc of the drive signal COM, there is prevented ejection of ink droplets, which would otherwise be caused by faulty operation of the piezoelectric elements 11 .
Operation of the head driving device 10 to be performed during printing operation of the ink jet printer will now be described. As shown in FIG. 3 , when the drive signal COM is higher than the intermediate potential, the electrodes 11 a of the piezoelectric elements 11 are charged by way of the first transistor 15 of the current amplifier 13 in accordance with fluctuations in the drive signal COM. When the drive signal COM is lower than the intermediate potential, the electrodes 11 a of the piezoelectric elements 11 discharge an electric current via the second transistor 16 of the current amplifier 13 . As a result, the piezoelectric elements 11 operate in accordance with the drive signal COM, thereby ejecting ink droplets.
At that time, as shown in FIG. 3 , the analog switch 26 is activated only during the non-driving period of the drive signal COM (i.e., when the potential of the drive signal becomes the intermediate potential). Hence, the charger 22 always charges the capacitor 21 of the bias potential provider 20 with the intermediate potential.
As a result, the intermediate potential Vc is applied to the common electrodes 11 b of the piezoelectric elements 11 from the capacitor 21 . Hence, the electrodes 11 b are always held at the intermediate potential Vc as indicated in dashed lines “b” shown in FIG. 3 .
Operation of the head driving device 10 to be performed at the end of the printing operation of the ink jet printer (e.g., when the ink jet printer is deactivated) will now be described.
At the time of completion of printing operation, the drive signal COM to be output from the head driver 12 to the current amplifier 13 is discharged from the electrodes 11 a of the piezoelectric elements 11 via the second transistor 16 of the current amplifier 13 , whereby the electrodes 11 a fall to zero potential.
At this time, the analog switch 26 is turned on, whereby the drive signal COM is applied to the base of the transistor 23 of the charger 21 . However, since the drive signal COM is in the midst of a gradual fall, the transistor 23 remains deactivated.
The capacitor 21 of the bias potential provider 20 is grounded via the resistor 24 . Therefore, the capacitor 21 is gradually discharged. Since the charging voltage of the capacitor 21 falls to zero, the electrodes 11 b of the piezoelectric elements 11 also gradually fall in potential, as indicated by dashed lines “b” shown in FIG. 4 , to thereby reach zero.
The ground-side electrodes 11 b of the piezoelectric elements 11 gradually reach zero potential as in the case of the electrodes 11 a to be activated by the drive signal COM. Therefore, a potential difference between the electrodes 11 a , 11 b of the piezoelectric elements is suppressed to a low level. Accordingly, the potential difference is lower than the intermediate potential Vc of the drive signal COM, and hence there is prevented ejection of ink droplets, which would otherwise be caused by faulty operation of the piezoelectric elements 11 .
In this way, the power to be dissipated by the piezoelectric elements 11 is diminished, and a voltage drop stemming from spontaneous discharge of the piezoelectric elements is small, which in turn reduces a power loss.
A potential difference between the piezoelectric elements 11 to be driven and the piezoelectric elements 11 not to be driven becomes small. Hence, even when these piezoelectric elements 11 are located adjacent to each other, electric discharge arising between the piezoelectric elements 11 is diminished. Moreover, even when the withstand voltage of each of the piezoelectric elements 11 becomes lower as a result of an increase in arrangement density, providing insulation between the piezoelectric elements 11 is unnecessary. Hence, an increase in arrangement density of a head can be achieved easily.
Since the capacitor 21 is charged by utilization of a head drive voltage, a specific power supply circuit to be used for producing the intermediate potential Vc is not required.
FIG. 5 shows an exemplary configuration of a switcher which can be used in place of the analog switch 26 .
As shown in FIG. 5 , a switcher 30 comprises, in lieu of the analog switch 26 , a transistor 31 connected to a point located between the base of the transistor 23 , the emitter of the first transistor 15 , and the emitter of the second transistor 16 , both transistors 15 , 16 belonging to the current amplifier 13 ; and a transistor 32 connected to a point located between the base of the transistor 31 and the ground by way of a resistor 33 .
A resistor 34 is connected to the base and emitter of the transistor 31 .
An activation/deactivation control signal output from the control section of the printer main unit is input to the base of the transistor 32 .
By the switcher 30 of such a configuration, as a result of a high-level control signal being input to the base of the transistor 32 , the drive signal COM flows to the ground via the resistors 33 , 34 , thereby applying a voltage to the base of the transistor 31 . Thus, the transistor 31 is activated.
As a result of a low-level control signal being input to the base of the transistor 32 , the potential of the base of the transistor 31 and the potential of the emitter of the transistor 31 are held at the same potential, and consequently the transistor 31 is deactivated.
Activation and deactivation of the switcher 30 are controlled by the control signal in the same manner as employed for the analog switch 26 .
As shown in FIG. 6 , a head driving device 40 according to a second embodiment of the invention is substantially identical in configuration with the head driving device 10 shown in FIG. 1 . Those constituent elements which are the same as those of the head driving device 10 are assigned the same reference numerals, and their explanations are omitted.
As in the case of the head driving device 10 shown in FIG. 1 , the head driver 12 , the current amplifier 13 , the switcher 14 , and the bias potential provider 20 are mounted on a print head 41 (or a carriage supporting a print head 17 ).
The analog switch 26 of the bias potential provider 20 is constituted by utilization of an unused switching section of the switcher 14 mounted on the print head 41 .
The head driving device 40 of such a configuration operates in the same manner as does the head driving device 10 shown in FIG. 1 . Since the analog switch 26 utilizes an unused switch section of the switcher 14 , a smaller number of parts are required, whereby the cost of parts and an assembly cost can be reduced.
In the above embodiments, the charger 22 is constituted of the transistor 23 , the resistor 24 , the capacitor 25 , and the analog switch 26 . However, the charger is not limited to such a circuit. A charger of another arbitrary configuration can also be used, so long as the circuit can supply a constant voltage from the constant voltage power supply Vcc to the capacitor 21 .
As shown in FIG. 7 , a head driving device 100 according to a third embodiment of the invention comprises: piezoelectric elements 11 provided so as to correspond to a plurality of nozzles of an ink jet printer; a head driver 12 for supplying a drive signal to electrodes 11 a of the respective piezoelectric elements 11 ; a current amplifier 13 and a switcher 14 , both being interposed between the head driver 12 and the respective piezoelectric elements 11 ; a bias potential provider 20 for applying a predetermined bias voltage to ground-side electrodes 11 b of the piezoelectric elements 11 ; a control resistor 121 ; and a capacitor 122 . Those constituent elements which are the same as those of the head driving devices according to the above embodiments are assigned the same reference numerals, and their explanations are omitted.
The head driver 12 is embodied as a driver IC 130 and generates a drive signal COM to be sent to the print head placed in, e.g., a main unit of the printer.
In this case, the head driver 12 is constituted of a latch 12 a ; a D/A converter 12 b ; and an amplifier 12 c.
In this embodiment, the latch 12 a is arranged so as to receive 10-bit data signals DATA 0 to DATA 9 output from the control section of the printer main unit, and a clock signal is input to a clock terminal CLK 1 of the latch 12 a.
In accordance with the data signals DATA 0 to DATA 9 input to the D/A converter 12 b by way of the latch 12 a , the D/A converter 12 b outputs an analog signal corresponding to a drive voltage through D/A conversion.
Further, the amplifier 12 c amplifies the analog signal output from the D/A converter 12 b , to thereby produce a predetermined drive voltage waveform.
The bias potential provider 20 is formed from a latch 123 , a D/A converter 124 , and an amplifier 125 in the same manner as is the head driver 12 .
In the case of the illustrated embodiment, the latch 123 receives the 10-bit data signals DATA 0 to DATA 9 output from the control section of the printer main unit of the ink jet printer, and a clock signal is input to a clock terminal CLK 2 of the latch 123 .
In accordance with the data signals DATA 0 to DATA 9 input by way of the latch 123 , through D/A conversion the D/A converter 124 outputs an analog voltage corresponding to the bias voltage.
Further, the amplifier 125 amplifies an analog voltage output from the D/A converter 124 , thus producing a predetermined bias voltage.
The bias potential provider 20 constituted of the latch 123 , the D/A converter 124 , and the amplifier 125 is housed in the driver IC 130 constituting the head driver 12 and embodied as a single IC package.
In this way, the bias potential provider 20 outputs, to the ground-side electrodes 11 b of the piezoelectric elements 11 , a predetermined bias voltage Vb, preferably a voltage substantially equal to the intermediate potential Vc of the drive signal COM output from the head driver 12 , as shown in FIG. 8 .
The control resistor 121 is a so-called coupling resistor and charges the capacitor 122 with the bias voltage Vb output from the bias potential provider 20 . At the time of discharging operation of the capacitor 122 , the control resistor 121 limits the current discharged from the capacitor 122 .
The control resistor 121 is set to hundreds of ohms (e.g., 200 Ω) so as to enable smooth charging of the capacitor 122 and to effectively limit a discharge current.
The capacitor 122 is an electrolytic capacitor. One end of the capacitor 122 is connected to the ground-side common electrodes 11 b of the piezoelectric elements 11 , and the other end of the capacitor 122 is grounded such that a charging voltage of the capacitor; i.e., the bias voltage Vb, is applied to the common electrodes 11 b of the respective piezoelectric elements 11 .
The capacitance of the capacitor 122 is selected so as to assume sufficient capacitance with respect to a total amount of electrostatic capacitance of all the piezoelectric elements 11 (a total of several microfarads; e.g., approximately 1.4 μF); that is, thousands of microfarads (e.g., approximately 3300 μF) so that the stable bias voltage Vb can be supplied to the respective piezoelectric elements 11 .
The head driving device 100 of the embodiment is constructed in the manner set forth and operates in the following manner.
First, operation to be performed at the time of activation of the ink jet printer will be described in accordance with a flowchart shown in FIG. 9 .
When the ink jet printer is activated, the control section of the printer main unit detects a head temperature (step A 1 ), and calculatively determines an intermediate voltage Vc 1 corresponding to the thus-detected temperature (step A 2 ). Incidentally, the temperature detected in the step A 1 may be a temperature in the vicinity of the print head, an environmental temperature of the printer, or the like.
Subsequently, the control section of the printer main unit activates all nozzles of the printer head (step A 3 ). In step A 4 , the control section gradually increases digital values represented by the data signals DATA 0 to DATA 9 while delivering a clock signal to the cock terminal CLK 1 , thus controlling the D/A converter of the head driver 12 .
As a result, by way of the switcher 14 an electric current flows from the first transistor 15 of the current amplifier 13 in response to the drive signal COM, thereby charging the electrodes 11 a of the piezoelectric elements 11 . As indicated by reference symbol A shown in FIG. 10A , the electrodes 11 a of the piezoelectric elements 11 increase up to the intermediate potential Vc 1 .
Subsequently, the control section of the printer main unit outputs a digital value of the intermediate potential Vc 1 in the form of the data signals DATA 0 to DATA 9 (step A 5 ). In step A 6 , the control section outputs one dock pulse to the CLK 2 terminal of the latch 123 of the bias potential provider 20 , thereby controlling the D/A converter 124 of the bias potential provider 20 .
As a result, the bias potential provider 20 applies a bias voltage Vb (=Vc 1 ) to the capacitor 122 by way of the control resistor 121 , thus charging the capacitor 122 . The charging voltage of the capacitor 20 gradually increases up to the intermediate potential Vc 1 in accordance with a time constant defined by the control resistor 121 and the capacitor 122 . As indicated by reference symbol B shown in FIG. 10B , the potential of the ground-side electrodes 11 b of the piezoelectric elements 11 gradually increases and finally reaches the intermediate potential Vc 1 . Accordingly, a potential difference between the electrodes 11 a , 11 b of the piezoelectric elements becomes substantially zero. At this point, the operation of the printer driver to be performed at the activation is completed.
The bias voltage Vb stored in the capacitor 122 is applied to the ground-side electrodes 11 b of the piezoelectric elements 11 . Hence, the amplifier 125 of the bias potential provider 20 does not need to be a high-speed operable type; an amplifier which outputs a small electric current will be sufficient.
Next, the operation of the head driving device to be performed at the commencement of printing operation will now be described by reference to a flowchart shown in FIG. 11 . In accordance with the flowchart shown in FIG. 11 , when commencement of printing operation of the ink jet printer is instructed, the control section of the printer main unit detects a temperature (step B 1 ), and calculatively determines an intermediate voltage Vc 2 corresponding to the thus-detected temperature (step B 2 ). Incidentally, the temperature detected in the step B 1 may be a temperature in the vicinity of the print head, an environmental temperature of the printer, or the like.
Subsequently, the control section of the printer main unit activates all the nozzles of the printer head (step B 3 ). In step B 4 , the digital value represented by the data signals DATA 0 to DATA 9 is caused to change gradually. As a result of the clock signal being input to the dock terminal CLK 1 , the D/A converter 12 b of the head driver 12 is controlled.
As a result, when Vc 1 <Vc 2 , an electric current flows into the electrodes 11 a of the piezoelectric elements 11 from the first transistor 15 of the current amplifier 13 by way of the switcher 14 in accordance with the drive signal COM, thereby charging the electrodes 11 a . As indicated by reference symbol C shown in FIG. 10A , the voltage of the electrodes 11 a reaches the intermediate potential Vc 2 . When Vc 1 >Vc 2 , an electric current is discharged from the electrodes 11 a of the piezoelectric elements 11 by way of the second transistor 16 of the current amplifier 13 , whereby the piezoelectric elements 11 are operated in accordance with drive signal COM, thus ejecting ink droplets.
Subsequently, the control section of the printer main unit outputs a digital value of the intermediate potential Vc 2 in the form of the data signals DATA 0 to DATA 9 (step B 5 ). In step B 6 , the control section outputs one clock pulse to a CLK 2 terminal of the latch 123 of the bias potential provider 20 , thus controlling the D/A converter 124 of the bias potential provider 20 .
As a result, the bias potential provider 20 applies the bias voltage Vb (=Vc 2 ) to the capacitor 122 by way of the control resistor 121 , thereby charging the capacitor 122 . Eventually, a charging voltage of the capacitor 20 gradually changes up to the intermediate voltage Vc on the basis of the time constant defined by the control resistor 121 and the capacitor 122 . As indicated by reference symbol D shown in FIG. 10B , the potential of the ground-side electrodes 11 b of the piezoelectric elements 11 also changes gradually, to thereby reach the intermediate potential Vc 2 . Accordingly, a potential difference between the electrodes 11 a , 11 b of the piezoelectric elements becomes substantially zero. At this point, the operation of the head driving device to be performed at the commencement of the printing operation is completed.
When printing operation is performed in this state, the electrodes 11 a of the piezoelectric elements 11 are charged by way of the first transistor 15 of the current amplifier 13 in accordance with variations in the drive signal COM during a period in which the voltage of the drive signal COM is increasing. During a period in which the voltage of the drive signal COM is decreasing, the electrodes 11 a of the piezoelectric elements 11 discharge an electric current by way of the second transistor 16 of the current amplifier 13 . As a result, the piezoelectric elements 11 operate in accordance with the drive signal COM, thereby ejecting ink droplets.
Next, the operation of the head driving device to be performed at the deactivation will be described in accordance with a flowchart shown in FIG. 12 . When the deactivation of the ink jet printer is instructed, the control section of the printer main unit activates all the nozzles of the printer head (step C 1 ). In step C 2 , the control section sets the data signals DATA 0 to DATA 9 to zero. In step C 3 , one dock pulse is provided to the dock terminal CLK 2 of the latch 123 of the bias potential provider 20 .
As a result, the D/A converter 124 of the bias potential provider 20 outputs an analog signal corresponding to a bias voltage Vb=0. Hence, the amplifier 125 outputs a zero bias voltage.
Eventually, the capacitor 122 is discharged. The electric current discharged from the capacitor 122 is gradually discharged from the bias potential provider 20 to the ground while passing through the control resistor 121 . In association with this discharging operation, the potential of the ground-side electrodes 11 b of the piezoelectric elements 11 also falls to zero as indicated by symbol E shown in FIG. 10B .
Subsequently, after elapse of a preset given period of time required for causing the capacitor 122 to discharge (step C 4 ), the control section of the printer main unit gradually decreases the digital value represented by the data signals DATA 0 to DATA 9 (step C 5 ). The control section controls the D/A converter of the head driver 12 by inputting a clock signal to the clock terminal CLK 1 .
As a result, an electric current flows from the electrodes 11 a of the piezoelectric elements 11 to the ground by way of the switcher 14 and the second transistor 16 of the current amplifier 13 . As indicated by reference symbol F shown in FIG. 10A , the potential of the electrodes 11 a of the piezoelectric elements 11 falls to zero.
As a result of the potential of the electrodes 11 a of the piezoelectric elements 11 and that of the electrodes 11 b of the same having dropped to zero, the operation of the head driving device to be performed at the deactivation is completed, and subsequently power is turned off.
In this way, the potential of the ground-side electrodes 11 b of the respective piezoelectric elements 11 is held at the bias voltage Vb; preferably, the intermediate potential Vc, by the charging voltage of the capacitor 122 supplied from the bias potential provider 20 . Hence, the potential difference between the electrodes 11 a , 11 b of the piezoelectric elements 11 is held at substantially zero. When piezoelectric elements to be driven and piezoelectric elements not to be driven are located adjacent to each other, a potential difference across the electrodes 11 a of the piezoelectric elements 11 is also held substantially at zero.
A voltage drop stemming from self-discharge of the piezoelectric elements 11 is small, thereby diminishing a power loss.
A potential difference between the piezoelectric elements 11 to be driven and the piezoelectric elements 11 not to be driven becomes low. Hence, even when these piezoelectric elements 11 are located adjacent to each other, electric discharge arising between the piezoelectric elements 11 is diminished. Moreover, even when the withstand voltage of each of the piezoelectric elements 11 becomes lower as a result of an increase in arrangement density, provision of insulation between the piezoelectric elements 11 is not required. Hence, an increase in arrangement density of a head can be easily achieved.
The bias potential provider 20 is constituted integrally with the head driver 12 as a single driver IC 130 . Hence, only a small packing space is required. Moreover, both data signals to be input to the bias potential provider 20 and those to be input to the head driver 12 are 10-bit common data signals. Hence, smaller wiring and connection space is sufficient.
A bias voltage of the bias potential provider 20 is applied to the capacitor 122 by way of the control resistor 121 . The amplifier 125 of the bias potential provider 20 does not need to be a high-speed operable type; a low-cost, small-capacity amplifier can be employed.
The electric current discharged from the capacitor 122 is limited by the control resistor 121 , thereby preventing flow of a large electric current into the bias potential provider 20 . Hence, the amount of heat dissipated by the amplifier 125 of the bias potential provider 20 can be greatly reduced.
In the embodiment, the bias potential provider 20 outputs a bias voltage Vb equal to the intermediate voltage Vc of the drive signal COM output from the head driver 12 . However, the bias potential provider 20 may output a bias voltage Vb offset from the intermediate voltage Vc.
In this case, a potential between the electrodes 11 a , 11 b of the piezoelectric elements 11 does not become substantially zero However, when compared with a case where the bias voltage is not employed, the potential difference becomes smaller, thereby reducing power to be consumed by the piezoelectric elements. Moreover, a voltage drop stemming from spontaneous discharge of the piezoelectric elements becomes smaller, thereby reducing a power loss. Occurrence of electric discharge resulting from a potential difference between the piezoelectric elements to be driven and the piezoelectric elements not to be driven is also diminished. Even when the piezoelectric elements are made compact and their withstand voltages become lower, the piezoelectric elements can cope with the drive signal. Hence, the arrangement density of the piezoelectric elements can be made increased further without involvement of an operation for providing insulation between electrodes of the piezoelectric elements.
In the embodiments, the 10-bit data signals DATA 0 to DATA 9 are input to the bias potential provider 20 , as in the case of the head driver 12 . However, data signals of smaller bits may also be employed.
In this case, the bias voltage may be in the vicinity of an intermediate voltage of the drive signal. Further, the bias voltage may also be less accurate than the drive signal. Hence, for example, an 8-bit data signal may be employed, so long as the maximum value and resolution of the bias voltage are halved. Accordingly, use of an 8-bit latch 123 and an 8-bit D/A converter 124 leads to cost reduction.
Although all the nozzles are turned on in step A 3 shown in FIG. 9 , in step B 3 shown in FIG. 11 , and in step C 1 shown in FIG. 12 , all the nozzles may be deactivated. In this case, substantially no current flows through the two transistors 15 , 16 of the current amplifier 13 , thus yielding the same result. Moreover, activation or deactivation of the nozzles does not need to be determined. However, in this case, there arises a problem of failure to determine an electric current to flow in a charging/discharging process.
In the above embodiments, the piezoelectric elements 11 are embodied by elements exhibiting the piezoelectric effect. However, other elements; e.g., electrostrictive elements or magnetostrictive elements, may be employed.
The invention can be also applied to display manufacturing apparatuses, electrode forming apparatuses, biochip manufacturing apparatuses, or various types of liquid jetting apparatuses, as well as ink jet printers. Furthermore, the invention can be also applied to a jetting apparatus in which any kinds of gas is selected as a jetted object.
|
There is disclosed a head driving device which drives a plurality of pressure generating elements for generating pressure fluctuation in a jetted object contained in each of associated pressure chambers formed in a jetting head of a jetting apparatus to eject the jetted object from each of nozzles communicated with the associated pressure chambers. In the device, a head driver generates a drive signal which is selectively applied to at least one of the pressure generating elements to be driven. A bias potential provider selectively applies a bias potential to at least one of the pressure generating elements not to be driven.
| 1
|
FIELD OF THE INVENTION
[0001] The present invention relates to a detection apparatus, and particularly to a biochemical detection apparatus. The biochemical detection apparatus is capable of performing detection for an environmental parameter or a biological parameter by a biochemical sheet and an electronic computing device without time and location limitations.
BACKGROUND OF THE INVENTION
[0002] In the early years, when detection for an environmental parameter such as the amount of a metal component of a contaminant or a pH value in the environment, or for a biological parameter such as blood sugar in the human body, is performed by a biochemical sheet, the object under test, i.e., the contaminant or blood sugar, is mixed with a reactant on the biochemical sheet to produce a change. A precision apparatus or manual means is the applied to identify or determine whether the object under test satisfies a standard.
[0003] The above manual means for detecting an object under test is time saving. However, the change after a reaction of the object under test may vary due to the observation and determination of different individuals, leading to unstable outcomes that cannot be relied upon as a reference standard in the subsequent detection. Further, conventional biochemical sheets used for specific detection are more costly. Once the number of times of detection gets large, the amount of biochemical sheets used is increased to inevitably increase investment costs of a business entrepreneur.
[0004] Therefore, a method of an optical image extending apparatus is proposed to improve the determination method performed by manual means. With an optical lens disposed, an image capturing unit captures an image of a change result in a biochemical sheet, and the image is further extended and determined. The accuracy and efficiency of such method are higher than those of the determination method by manual means.
[0005] However, current commercially available optical image extending apparatuses not only have sophisticated and complex components and higher costs, but also have an excessively large overall volume such that they are not readily portable and hence quite inconvenient. Thus, these optical image extending apparatuses may not be applied to immediately detect an object under test, such as the amount of a metal component or a pH value of the environment or a biological parameter of the human body. Therefore, there is a need for a solution that solves the drawbacks of high costs and the incapability of immediate detection due to poor portability of a conventional optical image extending apparatus.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a biochemical detection apparatus incorporating an electronic computing device and a low-cost and readily portable optical device having a small volume. Thus, the biochemical detection apparatus of the present invention is capable of immediately detecting an environmental parameter such as the amount of a metal component of a contaminant in the environment or a pH value, or a biological parameter such as blood sugar in the human body.
[0007] According to the above object, the present invention provides a biochemical detection apparatus including an electronic computing device and an optical device. The electronic computing device includes at least one display unit, and at least one image capturing unit coplanar with the display unit. The optical device includes a main body. The main body includes an accommodating device provided in the main body, an insertion slot in communication with the accommodating space, an optical lens in communication with the accommodating space, and an opening in communication with the accommodating space. The optical lens and the opening are disposed on a same plane of the main body, and the optical lens is located above the image capturing unit.
[0008] The biochemical detection apparatus further includes a biochemical sheet inserted in the insertion slot. The biochemical sheet includes a test area and a calibration area disposed at one end thereof. The test area and the calibration area are located above the image capturing unit.
[0009] The present invention provides features below.
[0010] 1. In the present invention, the optical device is a readily portable and low-cost structure having a small volume. Thus, a user may immediately apply the present invention to a fluid or a gas in the environment to detect the amount of a metal component of a contaminant, a pH value, or the presence of contamination, or to detect an object under test such as a biological fluid in the human body, including blood, urine or saliva to conveniently monitor the level of a special an analyte (e.g., glucose, cholesterol, ketone or a specific protein) existing in the fluid. To put to application, an object under test is added to the test area of the biochemical sheet to allow the object under test to mix with a biochemical reactant on the test area. The biochemical sheet is then inserted into the insertion slot to cause the test area to align with the optical lens, so as to allow the image capturing unit to scan a change result of the test area, and to perform image extension and determination. The detection result is displayed on the display unit immediately for the user to determine detection data of the object under test, thereby solving the drawbacks of high costs and the incapability of immediate detection due to poor portability of an expensive conventional apparatus.
[0011] 2. Through an application program, the electronic computing device of the present invention divides a part of the display unit into a light emitting area, and locates the light emitting area below the opening of the main body to have the illumination from the light emitting area serve as a main light source for the image capturing unit to capture an image of the test area. The light beams of the light emitting area further irradiate into the accommodating space through the opening to provide the image capturing unit with sufficient light beams for scanning and facilitating the observation of the change result of the test area.
[0012] 3. Through the application program, the electronic computing device of the present invention simultaneously divides the display unit into the light emitting area and a display area. Thus, the user is allowed to at the same time observe the change result of the test area through the display area while the image capturing unit scans the change result of the test area.
[0013] 4. In the present invention, one end of the biochemical sheet is simultaneously embedded with the test area and the calibration area. Thus, the user may directly compare the change result of the test area with a comparison reference object at the calibration area to determine the difference between the change result and the comparison reference object, which is distinct from the drawback of the test area and the calibration area belonging to two different objects and being more costly and inconvenient in a conventional solution.
[0014] 5. When detection is performed using the biochemical sheet, the detection result can be manually observed. Alternatively, the image capturing unit is controlled through the application program to cause the image capturing unit to automatically scan the change result of the test area and the comparison reference object. A difference between the change result of the test area and the comparison reference object is then automatically calculated, and the calculated result is displayed on the display area.
[0015] 6. In the present invention, a focusing target object is embedded in the calibration area to allow the image capturing unit to perform preceding operations including focusing, image alignment and light source adjustment to enhance the detection accuracy.
[0016] 7. The electronic computing device of the present invention may store the calculated result to a database to serve for data statistics, data analysis and subsequent remote support applications.
[0017] 8. In the present invention, with the optical lens disposed between the test area and the image capturing unit, the image capturing unit is allowed to scan the change result of the test area through the properties of the optical lens to provide image extension. Thus, the test area is capable of detecting the object under test with the biochemical reactant in a quite small area, thereby reducing the area that the test area requires and reducing the object amount under test, increasing the amount of detection and reducing investment costs of the business entrepreneur.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an exploded perspective view of an electronic computing device and an optical device of the present invention;
[0019] FIG. 2 is an exploded perspective view of an optical device and a biochemical sheet of the present invention;
[0020] FIG. 3 is a perspective sectional view of an optical device and a biochemical sheet of the present invention;
[0021] FIG. 4A is a planar view of an assembly of an electronic computing device, an optical device and a biochemical sheet of the present invention;
[0022] FIG. 4B is a sectional view of FIG. 4A along 4 B- 4 B;
[0023] FIG. 5 is a schematic diagram of a biochemical detection apparatus of the present invention in another application form;
[0024] FIG. 6 is a planar view of a fixing member according to a first embodiment of the present invention;
[0025] FIG. 7 is a perspective view of a fixing member according to a second embodiment of the present invention; and
[0026] FIG. 8 is a perspective view of an electronic computing device in another form and an optical device of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] Referring to FIG. 1 to FIG. 3 showing a biochemical detection apparatus 1 of the present invention, the biochemical detection apparatus 1 includes an electronic computing device 2 and an optical device 3 . The electronic computing device 2 includes at least one display unit 20 , and at least one image capturing unit 21 coplanar with the display unit 20 . The optical device 3 includes a main body 30 , which includes an accommodating space 300 provided in the main body 30 , an insertion slot 301 in communication with the accommodating space 300 , an optical lens 302 in communication with the accommodating space 300 , and an opening 303 in communication with the accommodating space 300 . The optical lens 302 and the opening 303 are disposed on a same plane of the main body 30 , and the optical lens 302 is located above the image capturing unit 21 . In an embodiment of the present invention, the electronic computing device 2 may a handheld smart mobile device with a computing function, or may be an electronic computing device such as a laptop computer 6 or a tablet computer shown in FIG. 8 . Further, the display unit 20 and the image capturing unit 21 are located at a same front side. More specifically, the display unit 20 and the image capturing unit 21 may be implemented as a screen and a lens at a front side, respectively. Alternatively, the display unit 20 and the image capturing unit 21 may be implemented as a screen and a lens at a rear side, respectively. In the embodiment of the present invention, for example but not limited to, the optical lens 302 is a convex lens.
[0028] Referring to FIG. 4A and FIG. 4B , the biochemical detection apparatus 1 of the present invention further includes a biochemical sheet 4 . The biochemical sheet 4 , inserted in the insertion slot 301 of the main body 30 , includes a test area 40 and a calibration area 41 at one end thereof. The test area 40 and the calibration area 41 are accommodated in the accommodating space 300 , and are located above the image capturing unit 21 for the image capturing unit 21 to scan. The optical device 3 of the present invention is a readily portable structure having a small volume and a low cost. To put to application, an object under test is added to the test area 40 of the biochemical sheet 4 to allow the object under test to mix with a biochemical reactant on the test area 40 . The biochemical sheet 4 is then inserted into the insertion slot 301 to cause the test area 40 to align with the optical lens 302 , so as to allow the image capturing unit 21 to scan a change result of the test area 40 , and to perform image extension and a determination. The detection result is displayed on the display unit 20 immediately for the user to determine detection data of the object under test, thereby solving the drawbacks of high costs and the incapability of immediate detection due to poor portability of an expensive conventional optical image extending apparatus. The biochemical reactant on the test area 40 of the present invention is applicable to a fluid or a gas in the environment to detect the amount of a metal component of a contaminant, a pH value, or the presence of contamination, or to detect an object under test, e.g., blood sugar in a biological fluid including blood, urine saliva of the human body to conveniently monitor the level of a special an analyte (e.g., glucose, cholesterol, ketone or a specific protein) existing in the fluid.
[0029] In the present invention, the optical lens 302 is disposed between the test area 40 and the image capturing unit 21 . Thus, the image capturing unit 21 provides image extension through the properties of the optical lens 302 , such that the test area 40 is allowed to detect the object under test using the biochemical reactant having a quite small area, thereby reducing the area that the test area requires and reducing the object amount under test , increasing the amount of detection and reducing investment costs of a business entrepreneur.
[0030] In the present invention, when the test area 40 and the calibration area 41 at one end of the biochemical sheet 4 are accommodated in the accommodating space 300 , depending on actual conditions, the electronic computing device 2 may include an application program (not shown) electrically connected to the image capturing unit 21 . Through the application program, the electronic computing device 2 of the present invention divides one part of the display unit 20 into a light emitting area 200 , and locates the light emitting area 200 below the opening 303 of the main body 30 to have the illumination provided by the light emitting area 200 to serve as a main light source for the image capturing unit 21 to capture an image of the test area 40 . Further, light beams from the light emitting area 200 irradiate into the accommodating space 300 through the opening 303 to provide the image capturing unit 21 with sufficient light beams for scanning and facilitating the observation for a change result of the test area 40 . Alternatively, as shown in FIG. 5 , depending on actual conditions, the main body 30 includes a through hole 304 , which is located at one side of the main body 30 opposite the optical lens 302 and is in communication with the accommodating space 300 . The user may additionally apply an external light source such as a torch 5 to utilize illumination of the external light source as the main light source for the image capturing unit 21 to capture an image of the test area 40 . The light beams from the external light source irradiate into the accommodating space 300 through the through hole 304 to provide the image capturing unit 21 with more sufficient light beams for scanning a change result of the test area 40 . Further, when the illumination of the light emitting area 200 serves as the main light source for the image capturing unit 21 to capture the change result of the test area 40 , the external light source may also serve as an auxiliary light source for the image capturing unit 21 to capture the change result of the test area 40 .
[0031] As previous described, in the present invention, the light emitting area 200 on the display unit 20 provides a lighting function. Further, through the control of the application program, the shape of the light emitting area 200 may be made to be consistent with the shape of the main body 30 , so as to allow the optical lens 302 of the main body 30 to align with a center point of the image capturing unit 21 .
[0032] Further, the application program may control a position of the display unit 20 to form a display area 201 , which is located at a center part of the display unit 20 . The electronic computing device 2 of the present invention may simultaneously divide the display unit 20 into the light emitting area 200 and the display area 201 through the application program, hence allowing the user to at the same time observe the change result of the test area 40 while the image capturing unit 21 scans the change result of the test area 40 . Alternatively, through the control of the application program, the display unit 20 is caused to form the light emitting area 200 or the display area 201 at different time points, e.g., the display unit 20 activates only the light emitting area 200 during the detection, and activates the display area 201 to display the detection result after the detection is complete.
[0033] In one embodiment of the present invention, the main body 30 may be provided as a housing having better reflectivity. When light beams enter the accommodating space 300 , the light beams are less likely absorbed by the main body 30 . Thus, more light beams can be reflected to the test area 40 and the calibration area 41 , such that the image capturing unit 21 is provided with more sufficient light beams for scanning the change result of the object under test mixed with the biochemical reactant on the biochemical sheet 4 .
[0034] The calibration area 41 includes at least one comparison reference object (not shown). The comparison reference object is comparison reference data that is embedded in the calibration area 41 according to the type of the object under test to be detected. More specifically, to detect an amount of a metal component or a pH value, corresponding data such a comparison value or a form is embedded into the calibration area 41 to serve as a comparison standard for the current detection. To detect blood sugar in blood, urine or saliva, corresponding data is similarly embedded into the calibration area 41 , and so forth.
[0035] The present invention is suitable for various types of electronic computing devices. However, these electronic computing devices in different brands or models may have different screen display or brightness parameter settings, or numerous data settings (e.g. color temperature and white balance) of the image capturing unit 21 may also be different. Further, assuming that the image capturing unit 21 adopts non-automatic focusing and the precision levels by which the user operates and inserts the biochemical sheet 4 are different, undesired effects of image recognition and determination errors may be resulted if preceding calibration operations are not provided before the application of the biochemical sheet 4 . Therefore, the calibration area 41 of the present invention further includes at least one focusing target object (not shown), which is embedded into the calibration area 41 . Before the biochemical sheet 4 is inserted, calibration operations including insertion alignment, image focusing and white balance are first performed for the image capturing unit 21 of the electronic computing device 2 to enhance the detection accuracy. In one embodiment, the focusing target object may be implemented as a calibration object in form of a plurality of thick/thin strips or grids for aligning an object or a light source or calibrating white balance.
[0036] As previously described, one end of the biochemical sheet 4 is simultaneously embedded with the test area 40 and the calibration area 41 , so that the user may directly compare the change result of the test area 40 with the comparison reference object at the calibration area 41 , which is distinct from the drawback of the test area 40 and the calibration area 41 belonging to two different objects and being more costly and inconvenient of a conventional solution. It should be noted that, the comparison reference object or the focusing target object may be stored in the electronic computing device 2 . Further, the focusing target object may be an identification password of the manufacturer of the biochemical sheet 4 , hence allowing only predetermined biochemical sheets 4 to be activated and used for detection by the electronic computing device 2 .
[0037] Further, when detection is performed using the biochemical sheet 4 , the change result of the test area 40 can be manually observed. Alternatively, the image capturing unit 21 is controlled by the application program to cause the image capturing unit 21 to automatically scan the change result of the test area 40 and the comparison reference object. A difference between the change result of the test area 40 and the comparison reference object is then automatically calculated, and the calculated result is displayed on the display area 201 of the display unit 20 .
[0038] Further, the electronic computing device 2 includes a database (not shown) electrically connected to the application program. The calculated result of the application program may be stored in the database to serve for data statistics and data analysis purposes, or to serve for subsequent support applications after a connection is established with a remote server.
[0039] Referring to FIG. 6 and FIG. 7 , the optical device 3 includes a fixing member for fixing the main body 30 on the electronic computing device 2 . The fixing member is coplanar with the optical lens 302 and the opening 303 of the main body 30 , and is located between the optical lens 302 and the opening 303 . The fixing member may be implemented by an adhesive film 31 , a rubber band 31 a, or a clamping tool (not shown). In the present invention, the optical device 3 is fixed on the electronic computing device 2 using the fixing member, so as to prevent the electronic computing device 2 or the optical device 3 from human impacts that may dislocate the electronic computing device 2 or the optical device 3 .
|
A biochemical detection apparatus includes an electronic computing device and an optical device. The optical device includes a main body. The main body includes an accommodating space provided in the main body, and an insertion slot, an optical lens and an opening that are in communication with the accommodating space. The optical lens and the opening are disposed on a same plane of the main body, and the optical lens is located above an image capturing unit of the electronic computing device. The optical device may be installed at a handheld electronic computing device commonly carried by an individual, and is capable of immediately performing detection for an environmental parameter or a biological parameter by a biochemical sheet. The optical device having a simple structure is small in volume, convenient and low in cost, and may replace expensive precision detection apparatuses.
| 7
|
This application is a continuation, of application Ser. No. 08/311,537, filed Sep. 23,1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to ceramics, and more particularly to improving the properties of ceramic zirconia.
2. Description of the Previously Published Art Because of its toughness, wear resistance, harness, low thermal conductivity, and other properties, zirconia (ZrO 2 ) has found numerous ceramic applications. Typical of these uses (e.g., in gasoline or diesel engines) are wear buttons for valve tappets; valve seats; oxygen sensor sleeves; piston caps (for diesels), and precombustion chamber elements (for diesels). Typical non-auto engine uses include grinding balls, dies, check valves and the like.
As described in my related patent, U.S. Pat. No. 4,891,343, of Jan. 2, 1990, tetragonal zirconia, the most commonly used form of zirconia, can exist at room temperature, but is meltable and under stress tends to transform to the monoclinic form, with increase in volume and loss of various important properties.
Various modifications and/or treatments of zirconia have been tried in efforts to minimize conversion of tetragonal to the monoclinic form. One approach is to add a stabilizer containing expensive dysprosia (Dy 2 O 3 ) to the tetragonal zirconia.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a stabilized tetragonal zirconia which is cost effective. Properties of this stabilized tetragonal zirconia include improved: flexural strength, low temperature stability; fracture toughness; hardness; improved resistance to thermal shock, abrasion and erosion; and others.
It is a further object to stabilize ceramic zirconia without the use of expensive stabilizers, such as dysprosia.
It is also an object to provide shaped zirconia ceramics of superior thermal and mechanical properties.
These and further objects of the invention are achived by addition of small amounts of various stabilizers to tetragonal zirconia. In one example, the stabilizer is a mixture of Nd 2 O 3 , Y 2 O 3 , and CeO 2 . In another example, the stabilizer is a mixture of Y 2 O 3 and CeO 2 , without Nd 2 O 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As recognized by one skilled in the art, the preferred starting particle size of ZrO 2 powder is a tradeoff between finer sizes for increased reactivity sintering and larger sizes for easier powder handling during processing. In the invention described herein, the ZrO 2 powder preferably used has an average particle size below about 20,000 Angstrom units since the smaller, more reactive particle size aids sintering. For zirconia particles sizes below 200 Angstrom units, the present stabilizer system may become somewhat less effective, since material this fine is fairly stable, as discussed in 69 Jour. Phys. Chem, 1238 (1965). It may be noted that zirconia at 200 Angstrom units, so far as is known, is not available commercially in non-agglomerated form. Thus, the zirconia average particle size of less than 20,000 Angstrom units or above 200 Angstrom units is a preferred material. In such commercial powders, the zirconia is in the monoclinic form, except for the finest particles, which may be in the tetragonal form. On sintering, the stabilizers diffuse into the zirconia and changes it to the tetragonal form.
In the invention described herein, yttria and ceria are the preferred stabilizers. Yttria and ceria sources include the preferred nitrates, as well as other soluble salts such as oxalates, acetates, chlorides, etc. The stabilizers can also be added simply as oxides, in which case the calcination step described below to decompose the salts can be omitted. Solvents for the stabilizers in salt form include the preferred, i.e., low cost water, as well as other solvents such as isopropyl alcohol, acetone, etc. When all the materials are in oxide form, their solubility becomes irrelevant, and the liquid simply becomes a dispersion medium.
The zirconia can be admixed with the stabilizers in any conventional high shear mixer to form a slurry. It is preferred to have the slurry mixture carry at least about 70 weight % solids loading. Substantially any of the conventional processes such as spray, tumble, or pay drying may be used for drying the zirconia/additive slurry.
When the stabilizers are added in salt form, calcining is used to decompose the salts. The calcining temperature may vary in the range of from about 800° to 900° C. for about one hour.
The ZrO 2 powder, which has either a calcined salt, dried oxide or a mixture of the two, is milled for a period of time sufficient to provide complete homogeneity. The milling time will also depend on the particle size desired in the product.
The dry powder can be pressed into greenware shapes for sintering, e.g., at pressures of 8,000-15,0000 p.s.i. as conventionally used.
Sintering is the final step, and this should be carried in a furnace with the product exposed to air, preferably at about 1530° C. for about one hour. Higher temperatures could be used, but the grain size would adversely increase.
In addition to the yttria/ceria stabilizer described above, the other stabilizer adds Nd 2 O 3 to the yttria/ceria slurry. Any of these stabilizers are substantially cheaper to use than prior art stabilizers such as those described in my prior patent.
Table 1 below illustrates the ranges for the two types of stabilized ZrO 2 compositions according to the invention.
TABLE 1______________________________________Stabilized Zirconia Compositions Mole Percent Type 1 Type 2 Preferred PreferredIngredient Range Range______________________________________ZrO.sub.2 89.15-93.5 88.4-92.50Ceo.sub.2 5.5-7.0 6.0-8.93Y.sub.2 O.sub.3 1.0-1.5 1.0-2.0Nd.sub.2 O.sub.3 N/A 0.3-1.3______________________________________
Having described the basic aspects of the invention, the following examples are given to illustrate specific embodiments of stabilized zirconia compositions according to the invention.
EXAMPLE 1
This example describes the preparation of a stabilized zirconia composition according to the present invention.
The following ingredients were assembled:
ZrO 2 =112.9 g., 92.01 mole percent, average particle size about 1.2. μm;
Nd 2 O 3 =1.15 g, 0.34 mole percent;
Y 2 O 3 =2.26 g, 1.0 mole percent (from Y (NO 3 ) 3 ); and
CeO 2 =11.4 g, 6.65 mole percent (from Ce(NO 3 ) 4 ).
The nitrates were mixed in 1000 ml water with stirring for about two hours until completely dissolved, at which time the Nd 2 O 3 was added to form a slurry. The monoclinic zirconia powder (Z-Tech Corp. New Hampshire) was then added to the solution, and the slurry thoroughly mixed in a 1/2-liter plastic jar with 1/2 inch alumina balls. The slurry was then dried under a heat lamp to form a powder. The powder was calcined at 800°-900° C. for 1 hour, as described above, to decompose the nitrates to the oxide form. The calcined powder was milled a dry ball mill for ten (10) hours, and the processed powder was dry-pressed into a ceramic shape (0.24×0.15 inch cross section) and sintered in a furnace, in air, at 1530° C. for 2 hours.
EXAMPLES 2-4
Examples 2-4 were carried out by the same general procedure of Example 1 but using the ingredients set forth in Table 1 above. The precise amounts of the ingredients used are shown in Table 2.
RESULTS
The products from Examples 1-4 were analyzed using the conventional test procedures described below and the results are reported in Table 2.
1. Flexural strength: Four-point bend test. The specimens/bars were tested under the following conditions:
Spans: Inner=0.5". Outer=1.0".
Cross head speed: 0.02 in/min
Width of the bar (approx.)=0.1900 inches.
Thickness of the bar (approx.)=0.1300 inches.
Machine: Instron.
2. Low temperature stability: This test is performed in an autoclave maintained at 200° C. The water vapor pressure was 100 p.s.i. (this was generated by addition of approximately 3-4 ml of water at room temperature). The samples were held under the above conditions for 250 hours. The testing for degradation in strength was done using a dye penetrant and later tested for flexural strength.
3. Fracture toughness: This was measured using the indentation and the pre-notched beam technique. The experiments were done at 10-20 kg load.
4. Hardness: Vickers hardness was measured using 1 kg load.
5. Thermal shock: The theory of thermal shock evaluation is described by Hassellman in J. Amer. Ceram. Soc., Vol 52, No. 11 pages 600-604 (1969). Following Hassellman's technique the samples were heated to the desired temperature and equilibrated at that temperature for ten minutes before they were instantaneously quenched into the room temperature bath (at 25° C.) which was agitated vigorously when the sample was placed in the bath to maintain the bath at its constant temperature. The difference between the heated temperature and the room temperature quench is reported as the delta temperature in the thermal shock value in Table 2 through which the sample survived.
6. Thermal expansion: An Orton Dilatometer was used.
TABLE 2______________________________________ Influence of Stabilizers on Zirconia Mole PercentIngredient Ex. 1 Ex. 2 Ex. 3 Ex. 4______________________________________ZrO.sub.2 92.01 92.26.sup.1 90.7 88.37Y.sub.2 O.sub.3 1.0 1.1 2.0 1.80CeO.sub.2 6.65 6.63 6.0 8.93Nd.sub.2 O.sub.3 0.34 NA 1.3 0.9Flexural 655 (95,000) 655 (95,000) 680 (98,626) 670 (97,175)strength,MPa (psi)Low Temp. excellent excellent excellent excellentstabilityFracturetoughness, 10.0 10.0 9.5 9.8MPa m.sup.1/2Hardness,Kg/mm.sup.2 1150 1150 1150 1150Thermalshock 225 225 225 225(Hasselmen)Thermal 11.0 11.0 10.8 10.8expansion,×10.sup.-6 /°C.Elastic 172 172 172 172Modulus,GPa______________________________________ .sup.1 This composition also contained 0.01% inert materials to bring the percentages to 100.0%
It is understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of this invention.
|
The invention is directed to improved stabilized zirconia compositions and the processes for making the same. Low cost stabilizers, in the form of ceria/yttria or ceria/yttria/noedynium mixtures, are used to maintain zirconia in tetragonal form at room temperature without tending to convert back to monoclinic form at increased temperatures or while under stress.
| 2
|
RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Application No. 61/206,483, which is hereby incorporated by reference herein in its entirety.
GOVERNMENT INTERESTS
[0002] This invention was made with government support under contract number W909MY-08-C-0025, awarded by the Department of Defense. The government has certain rights in this invention.
FIELD OF THE INVENTION
[0003] The invention relates to fuel cells and with more particularity to manifolds for fuel cell systems.
BACKGROUND OF THE INVENTION
[0004] Manifolds are used to route and distribute air and fuel into various components of a fuel cell system. Current fuel cell systems utilize manifolds that are rigidly coupled to the fuel cell tubes. Therefore, current manifold designs are not adapted for portable applications in that current manifold designs are undesirably large, are not designed for mass manufacturability, and are not robust, shock, vibration, and thermal transitions.
[0005] For example, current manifolds do not allow fuel cell components to flex or comply to allow for variations in the position of fuel cell tubes relative to each other or relative to other fuel cell components. Further, rigid manifold connections do not allow for variations in fuel cell components for example structural variations, shape, straightness, or other toleranced dimensions that can vary during manufacturing. Rigid manifolds can restrict the packaging design and manufacturing options and can undesirably increase the overall size of portable fuel cells. Still further, current manifolds are not adapted for portability and current manifolds are not configured to manage thermal expansion differences between component materials. Therefore, there is a need for a fuel cell manifold that is compliant and that allows variations in the position of fuel cell tubes relative to each other and relative to other fuel cell components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a plan view of one embodiment of a fuel cell system including a manifold member in accordance with an exemplary embodiment of the present disclosure;
[0007] FIG. 2 is a side view and
[0008] FIG. 3 is a sectional view of the manifold member coupled to a plurality of fuel cell tubes of the fuel cell system of FIG. 1 ;
[0009] FIG. 4 is a perspective view of a fuel cell system including a manifold member in accordance with another embodiment of the present disclosure;
[0010] FIG. 5 is a plan view of the manifold of FIG. 4 with a lid removed detailing the plurality of outlets;
[0011] FIG. 6 is a plan view of the lid of FIG. 5 ;
[0012] FIG. 7 is a side view of a interconnecting member including a backpressure control member of the fuel cell system of FIG. 4 ;
[0013] FIG. 8 is a partial view of an end of a fuel cell system having a plurality of fuel cell tubes;
[0014] FIG. 9 is a partial perspective view of the manifold member connected to the plurality of fuel cell tubes of FIG. 4 ;
[0015] FIG. 10 is a partial sectional view showing one embodiment of a manifold member coupled to a fuel cell tubes;
[0016] FIG. 11 is a partial sectional view showing one embodiment of a compliant manifold coupled to a fuel cell tube;
[0017] FIG. 12 is a partial sectional view showing one embodiment of a compliant manifold having steps that engage and locate the reactor and fuel cell tube; and
[0018] FIG. 13 is a prospective view of a fuel cell tube.
SUMMARY
[0019] A solid oxide fuel cell module includes a manifold member comprising a plurality of openings. The solid oxide fuel cell module further includes a plurality of fuel cell tube units. The solid oxide fuel cell module further includes a fuel cell tube unit to manifold interconnect member providing a fluid flow channel between the manifold member and the plurality of tubes, wherein the fuel cell tube unit to manifold interconnect member comprises a polymer material.
DETAILED DESCRIPTION
[0020] Fuel cell systems in accordance with exemplary embodiments are described herein. In one embodiment, a manifold member distributes gas to multiple fuel cell tubes of the fuel cell system. The manifold member is connected to each of the fuel cell tubes such that a substantially gas-tight seal is maintained between an inner chamber of each fuel cell tube and an inner chamber of the manifold member. In one embodiment, a resilient interconnecting member couples the manifold to the fuel cell tubes. The resilient member allows for movement of the plurality of fuel cell tubes connected to the manifold member relative to other fuel cell components. The resilient member can dampen oscillations and reduce mechanical stresses on components of the fuel cell system due to movement of fuel cell components relative to each other. Movement of fuel cell components relative to each other can be caused by external forces on the fuel cell system (for example, vibrational movement), by thermal expansion mismatch between fuel cell system components and by fluid flow within the fuel cell system. Further, the resilient member can adapt to manufacturing variations in, for example, tube size and tube position and the resilient member can facilitate simplified manifold-to-tube assembly.
[0021] FIGS. 1-13 generally depict a fuel cell system 15 . Referring to FIGS. 3 and 13 , the fuel cell system 15 includes a fuel feed tube 20 and a fuel cell tube 18 . The fuel cell tubes extend in thermally insulated walls 11 . The fuel cell tube 18 and the fuel feed tube 20 together are a fuel cell tube unit 21 . The fuel feed tube 20 is disposed within an inlet portion 17 of the fuel cell tube 18 . Unreformed fuel enters an inlet portion 19 of the fuel feed tube 20 . The unreformed fuel is routed through the fuel feed tube 20 to an internal fuel reformer 52 where the fuel is reformed and the resulting reformed fuel is heated during the exothermic reformation reactions (for an exemplary fuel cell system having an internal fuel reformer, see U.S. Pat. No. 7,547,484 entitled SOLID OXIDE FUEL CELL WITH INTERNAL FUEL PROCESSING which is hereby incorporated by reference in its entirety. The fuel reformation reaction occurs downstream from the inlet portion 19 of the fuel cell tube 18 .
[0022] The fuel cell tubes 18 each comprises an anode layer, an electrolyte layer, and a cathode layer at an active portion 50 that generates electromotive force at the active portion 50 at operating temperatures in the range of 600 to 950 degrees Celsius. However, only the active portion 50 of the fuel cell tube 18 contains the anode layer, the electrolyte layer, and the cathode layer, and therefore, only a portion of the fuel cell tube 18 requires high operating temperatures for generating electromotive force. Therefore, the operating temperatures proximate the inlet portion 19 of the fuel cell tube 20 is less than 250 degrees Celsius, and in an exemplary embodiment, the operating temperature proximate the inlet portion 19 of the fuel cell tube 20 is between about 100 degrees Celsius and 250 degrees Celsius. Thus, low-temperature materials such as the flexible materials described for the interconnect member 30 be utilized to couple the fuel cell tubes 18 to the manifold member 10 .
[0023] The exemplary fuel cell tube 18 is a solid oxide fuel cell that is advantageously relatively lightweight and that can operate providing high power to mass ratio. As an example, the tube can be 1 mm-30 mm in diameter and can be heated rapidly. An example of a suitable fuel cell is disclosed in U.S. Pat. No. 6,749,799 to Crumm et al, entitled METHOD FOR PREPARATION OF SOLID STATE ELECTROCHEMICAL DEVICE which is hereby incorporated by reference in its entirety. Other material combinations for the anode layer, the cathode layer, and the electrolyte layer as well as other cross-section geometries (triangular, square, polygonal, etc.) will be readily apparent to those skilled in the art given the benefit of the disclosure.
[0024] The manifold member 10 can input fuel in one or more inlet openings and substantially evenly distribute fuel among multiple fuel cell tubes 18 of the fuel cell system 15 . The manifold member 10 can distribute fuel substantially evenly utilizing backpressure control members. Referring to FIG. 7 , in one embodiment, the backpressure control member 26 is disposed at a fuel inlet end of an interconnecting member 30 and has an orifice with a selected cross-sectional area to create a predetermined amount of backpressure to substantially evenly distribute fuel to each of the fuel cell tubes 18 . In one embodiment, backpressure control members are disposed within the plurality of fuel cell tubes. The cross-sectional area can be calibrated to create a selected amount of backpressure to regulate fuel flow from the manifold member 10 into each of the fuel cell tubes 18 of the fuel cell system 15 . The amount of backpressure desired for a specific backpressure control member can vary based on, for example, the travel path of fuel within the fuel cell system, the number of fuel cell tubes, and the width and length of the fuel cell tubes.
[0025] In one embodiment, the backpressure control member can provide functionality in addition to providing a calibrated cross-sectional area for creating a selected amount of backpressure. For example, in one embodiment, a current collector (not shown) disposed within the fuel cell tube 18 can have a calibrated cross-sectional area providing pneumatic resistance to create a selected amount of backpressure. Additionally, in another aspect, the backpressure control members may be integral with the fuel cell tubes 18 , that is, the fuel cell tubes 18 may have a calibrated cross-sectional area to provide a selected amount of pneumatic resistance.
[0026] The back pressure control member can reduce variability due to downstream pneumatic pressure thereby providing substantially uniforms fuel flow through each of the fuel cell tubes. For example, a fuel cell stack can operate at a nominal operating pressure of 2+/−0.5 inches (or a 25% variance range) without a back pressure control member. Back pressure control members tolerance to provide a 5+/−0.05 inches of back pressure can be added to the fuel cell stack with the nominal operating pressure of 2+/−0.5 inches thereby providing a fuel cell with a back pressure of 7+/−0.55 inches (or a 7.9% variance range).
[0027] In one embodiment, the fuel reforming reactor 52 disposed within the fuel cell tube 18 can have a calibrated cross-sectional area to create a selected amount of backpressure. In one embodiment, the backpressure control member can comprise multiple components within the fuel cell tube. For example, a fuel reforming reactor disposed within a fuel feed tube and a current collector can each have calibrated cross sectional areas to create a selected amount of backpressure such that the fuel is substantially evenly distributed among the fuel cell tubes.
[0028] Referring to FIGS. 1-3 , the manifold member 10 includes a manifold head 12 having an inlet 14 and a plurality of outlets 16 . The manifold member 10 comprises interconnecting members 30 to maintain gas-tights seals between an inner chamber of the manifold member 10 and an inner chamber each of the fuel cell tubes 18 . In one embodiment, the manifold member 10 may be utilized for coupling a plurality of fuel cell tubes 18 of the fuel cell system 15 to a fuel source such that the input of fuel into each of the plurality of fuel cell tubes 18 is substantially balanced. As shown in FIG. 3 , the plurality of fuel cell tubes 18 are received in and sealed relative to the plurality of outlets 16 of the manifold head 12 . In this manner, fuel introduced into the manifold member 10 passes to the plurality of fuel cell tubes 18 without escaping into an ambient portion of the fuel cell system 15 . In one aspect, and as shown in FIG. 3 , the plurality of fuel cell tubes 18 may be connected with the plurality of fuel feed tubes 20 that are inserted into and gas-tight coupled with the plurality of fuel cell tubes 18 . By integrating steps into the region of the manifold that is associated with the fuel cell tube, the fuel feed tubes and/or similar structures, the manifold member is further able to provide a support and provide a substantially gas tight fit between the manifold and each of the tubes to avoid leaking.
[0029] In one embodiment, the interconnecting members 30 comprise a flexible silicone-base polymer configured maintain a gas tight seal with the end of the fuel cell tube at temperatures above 100 degrees Celsius and more specifically temperatures of about 200 degrees Celsius to about 250 degrees Celsius. Other exemplary materials for interconnect members are described below:
[0000]
TABLE 1
Young's Elasticity Modulus
Material
Gpa
Rubber
0.01-0.1
LD Polyethylene
0.2
HD Polyethylene
0.8
Polystyrene
1.5-2
Nylon
3
Graphite
1.5
Cork
0.03
Polycarbonate
0.7
Polyurathane Elastomer
0.25
Silicone Polymer
0.01-0.1
[0030] Table 1 includes exemplary interconnecting member 30 material and associated Young's Elasticity Moduli for each material including rubber, low density (‘LD’) polyethylene, high density (“HD”) polyethylene, nylone, graphite, cork, polycarbonate, polyurethane elastomer, and silicone polymers. Other exemplary materials can further include other elastomers, natural rubber and synthetic rubber (e.g., nytrol), natural latex and synthetic latex (vinyl acetate, styrene-butadiene, and acrylates). The exemplary interconnect members can comprise a modulus of elasticity that is less than or equal to one tenth a modulus of elasticity of a portion of the fuel cell tube unit 21 contacting the manifold member. In one embodiment, the polymer material comprises an elastic modulus of less than 3 GPA, and more specifically less than 0.8 GPA. In one embodiment, the interconnect member comprises material having and elastic modulus of less than 0.1 GPA, for example silicone-based polymers, rubber and like materials.
[0031] The fuel cell manifold member 10 may have various shapes including, for example, a ring shape or a disc shape as shown in the figures. For example, the fuel cell tubes 18 may be positioned in any of a number of configuration including tube rays, tube bundles, and individual tubes. Further, it should be realized that various shapes and positions of the outlets 16 may be utilized. For example, the outlets 16 may be arranged in various patterns and formations to direct fuel to fuel cell tubes 18 configured in various positions.
[0032] Referring to FIG. 4 , in another aspect, a lid 22 may be removably connected to a top of the manifold head 12 to allow access into an interior of the manifold member 10 to simplify manufacturing through coupling of the manifold member 10 to a fuel cell as well as allow for replacement of various components of the fuel cell system. The manifold member 10 may also include an external circuit board (not shown) that may be attached to a top of the manifold head 12 .
[0033] The manifold member 10 may also include an active cooling mechanism associated with the manifold to regulate a temperature of the manifold. Various active cooling mechanisms including fans and blowers may be utilized to maintain a temperature range of the manifold 10 .
[0034] Referring to FIGS. 4-9 , there is shown a second embodiment of a manifold member 10 . The second embodiment of the manifold member 10 may include a plurality of interconnecting members 30 coupled in each of the plurality of outlets 16 and connected with the plurality of fuel cell tubes 18 . The plurality of interconnecting members 30 are flexible or “mechanically compliant” The term “mechanically compliant” as used herein, refers to the ability of the manifold member 10 to move relative to the plurality of fuel cell tubes 18 such that shocks and movements associated with the manifold member 10 may be absorbed by the interconnecting members 30 . As with the previously described embodiment, the manifold member 10 may include backpressure control members 28 , shown in FIG. 7 associated with each of the interconnecting members 30 for balancing the fuel flow into the plurality of fuel cell tubes 18 . The backpressure control members 28 may include a precision orifice or a precision orifice packaged in a cartridge, as well as a flow restrictor that is a capillary tube.
[0035] Referring to FIGS. 10-11 there are shown various structures of the plurality of interconnecting members 30 . In the depicted embodiment of FIG. 10 , the interconnecting member 30 is connected to the outlet member 16 and to the fuel feed tube 20 . In the embodiment depicted in FIG. 12 , the interconnecting member 30 is connected to the outlet member 16 and to the fuel cell tube 18 . A backpressure control member 28 , such as a precision orifice, may also be positioned within the interconnecting member 30 . In the embodiment depicted in FIG. 12 , the interconnecting member 30 includes stepped portions 31 to locate the fuel cell tube 18 and fuel feed tube 20 . In this manner the fuel feed tube 20 may be positioned longitudinally and radially with respect to the fuel cell tube 18 . It should be realized that the interconnecting member 30 may include various numbers of stepped portions 31 . For example, one of the steps shown in FIG. 11 may be removed such that either the fuel cell tube 18 or fuel feed tube 20 is positioned longitudinally with respect to the outlet member 16 . Alternatively, the step portions may allow the fuel cell tube or similar structure can to be integrated directly into the manifold member. Although the exemplary tube is shown in which both external and internal diameters are stepped in alternate embodiment, the tube can have an a continuously decreasing internal diameter, a stepped in diameter with a constant outer diameter, a lip or shoulder or other features to facilitate substantially gas tight connections with the fuel cell tubes and the fuel feed tubes.
[0036] The manifold member 10 as described above has a compact shape and design that allows for positioning of a manifold member 10 closely to the fuel cell tubes 18 and allows for the mounting of circuit boards 24 outside of a hot zone of the fuel cell system 15 . Additionally, the fuel cell system 15 provides passive fuel distribution and flow control such that a substantially similar amount of fuel is routed to each of the fuel cell tubes 18 .
[0037] Further, the manifold member 10 also provides a mechanically compliant manifold member 10 allowing variations in the position of the manifold member 10 relative to the fuel cell tubes 18 . The fuel cell system 15 includes internal reformers 52 that heat fuel inside the fuel cell tubes 18 , thereby allowing a low-temperature seal between the fuel cell tubes and the manifold member 10 .
[0038] The 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 limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.
|
A solid oxide fuel cell module includes a manifold member comprising a plurality of openings. The solid oxide fuel cell module further includes a plurality of fuel cell tube units. The solid oxide fuel cell module further includes a fuel cell tube unit to manifold interconnect member providing a fluid flow channel between the manifold member and the plurality of tubes, wherein the fuel cell tube unit to manifold interconnect member comprises a polymer material.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The following application claims benefit of U.S. Provisional Application No. 60982312, filed Oct. 24, 2007, which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] Putting is a very complicated and misunderstood part of the game of golf. Many factors go into becoming a proficient putter. Much of the confusion connected to putting derives from poor aim. Though, golfers do not intentionally aim incorrectly, an average of 97% (based on valid studies) of the current golfing population aims incorrectly. Accordingly, individualized putters and putter-fitting systems that account for an individual golfer's particular aiming quirks or foibles would be of great benefit.
SUMMARY OF THE INVENTION
[0003] A putter fitting method and system comprising a laser configured to deflect a laser beam off of a putter at address and strike a scoring map in such a way so as to indicate the any error's in a golfer's aim. The method and system may further comprise determining physical alterations to the golfer's putter in order to correct the aim errors. Such changes may be to the hosel (neck), hosel offset, hosel type, head shape, loft, line combination, length or the like. These changes may be suggested automatically, for example, by a computer program, based on the location of the laser strike, or by a human fitting professional.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a schematic diagram of a putter fitting system according to an embodiment of the present disclosure.
[0005] FIG. 2 is a schematic diagram of a putter fitting system according to an embodiment of the present disclosure
DETAILED DESCRIPTION
[0006] According to one embodiment, the present disclosure provides a putter fitting system that corrects for inaccurate aim by providing a fitting system that allows putters to be custom-fit to an individual golfer's particular needs. For the purposes of the present disclosure, the term “golfer” is used to refer to the person who is aiming the putter. The term “fitting professional” is used to refer to a person or entity (artificial or real) that provides suggestions to the golfer. In some cases the golfer and fitting professional may be the same person. Furthermore, the term “fitting professional” is not intended to require any type of professional knowledge, certification, or degree. Unless stated otherwise, the term “putter” is used to refer to a specific type of golf club that is used to putt the ball.
[0007] In one embodiment, the system described herein evaluates a golfer's putting aim (or aim and stroke, as described below) and provides suggested changes to individual variables in the putter so as to enable the golfer to optimize his or her putting ability. Putter variables include, but are not limited to, the alteration, replacement, or other modification to: hosels (necks), hosel offsets, hosel types, head shapes, lofts, line combinations (i.e., aiming guides or marks that can be drawn, machined, or otherwise provided on the top of the putter to help the golfer line up his or her shot), shaft lengths, grip sizes, grip types, and the like. Typically, these variables elicit a specific aiming response in an individual golfer. Changing one or more of these variables will typically produce an altered aiming response in the golfer.
[0008] According to one embodiment the evaluation process includes providing a system having a putter with a reflective surface on its face, a laser configured to direct a laser beam towards the face of the putter, and a scoring map on to which the laser beam is directed after being reflected by the putter face. The laser may be situated within a target that is intended to simulate, for the golfer, the cup into which the golf ball is to be putted. In this embodiment, a golfer who wishes to have his or her aim evaluated so that appropriate physical changes can be made to his or her putter (or to help him or her purchase a putter that is best suited for his or her particular aiming quirks), addresses a ball placed a given distance away from the laser as he or she normally would to putt the ball into the cup. It shall be understood that the “golf ball” that the golfer addresses with his or her putter need not be an actual golf ball, but could, instead be a representation of a golf ball, or some other object that provides a sufficient visual representation so as to allow the golfer to address the “golf ball” with his or her normal stance and (his or her believed) proper alignment. In some cases the target may be a cup-sized objective, a simulation thereof, or any other suitable target. Exemplary distances between the golf ball and the laser may be those distance at which one would normally putt the ball, e.g., between 0-3 ft, 0-6 ft, 0-12 ft, 0-36 ft, 3-18 ft, or any other suitable or desirable distance. The golfer aligns his or her putter behind the golf ball in the alignment that he or she believes is the alignment that, upon stroking the ball, would result in putting the ball at or into the target. As stated above, the putter face contains a mirror or otherwise suitably reflective surface situated thereon such that, after the golfer perceives that he or she is correctly aimed, the golf ball can be removed, and the laser beam is able to rebound or deflect off of the reflective surface on the putter face and strike the scoring map, thereby indicating the true aim of the player. Aim contains both lateral (putter face angle) and vertical (effective loft) elements. The particular position where the laser hits the mirror indicates to the fitting professional the necessary change in one or more physical variables of the putter to correct the aim response. The golfer can then be provided with a putter that includes one or more modifications suggested by the fitting professional as a result of the laser-assisted putter alignment test. This process is executed until the putter's variations correspond to the golfer's ability to correctly aim the putter towards the identified aiming point.
[0009] The scoring map may take the form of a mobile or immobile backdrop, wall, vertical surface, electronic monitor, computer screen, or the like. For the purposes of the present disclosure, the scoring map may also be referred to herein as a backdrop or panel. The scoring map may or may not have markings on it to help identify the golfer's aiming issues and/or provide suggestions regarding putter modifications. Accordingly, the present disclosure provides a process that allows for the evaluation of the laser aim response during a fitting session. This laser aim response is accurate and definable.
[0010] According to one embodiment, the scoring map is physically divided into small quadrants, which may or may not be visible to the golfer or the fitting professional. When the laser strikes the scoring map, it hits a physical location on the scoring map which is associated with one or more of these quadrants. Each quadrant may be assigned a code. The panel may be of any suitable size. For example, a 36″×28″ size panel has been found to be useful an embodiment of the presently disclosed invention. Suitable detection methods for evaluating which quadrant has been hit include photo cells within the backdrop or a camera system, for example placed directly behind the backdrop. Each quadrant may then be indicative of or associated with a particular aiming disparity, which can then be corrected by one or more physical changes to the golfer's putter.
[0011] In some embodiments, the putter fitting system includes a program that identifies the hit response and makes a recommendation for a change to the putter, for example, by recommending a different hosel, loft angle, aiming line, or combination thereof. The recommendation may be automatically generated by the program, or the program may simply alert the golfer or fitting professional that a change is indicated. If the program simply provides an alert, the fitting professional may then suggest alterations to the club based on some or all of the data generated by the fitting system. In an automated system (one in which the program makes suggestions), the program may be provided with putter-fitting rules. In some embodiments, these putter fitting rules may be provided by one or more fitting professionals based on real data, data modeling, past experience, general knowledge, belief, or the like. The program may also incorporate a learning program, which enables it to generate its own rules over time, based on cumulated data. Accordingly, the program may be designed to gain speed and accuracy over time to become smarter and more proficient.
[0012] It should be understood that this putter fitting system is not limited to one particular company's products, but could encompass variables from other company products and variations. In some embodiments, it may be preferably for the system to use an interchangeable component system. Such a component system could have calibrated variables that are quantifiable and known by the program, thereby increasing the likelihood of generating accurate suggestions to improve the golfer's aim response. In some embodiments, each variable in the system may have an identifying code so the fitting professional can accurately change the variables, i.e., putter head #1, loft plate 3 deg, hosel=L2 2 deg flat, line combination=one line middle bottom, length=34 inches.
[0013] After identifying a first aim response and providing a first putter recommendation, the system could be designed to repeat the process until the desired aim is achieved.
[0014] According to yet another embodiment, the backdrop evaluation system could be directly linked to a motion based system to evaluate the dynamic motion of the putter with its corresponding aim response. The program could evaluate the aim and motion of the putter and recommend physical changes in the variables necessary for better dynamic movement.
[0015] It is noted that according to some embodiments, the present system reviews the golfer's aim without requiring the golfer to hit the ball. Accordingly, unlike any method of putter fitting that evaluates ball flight (or roll), some embodiments of the presently described putter fitting method are independent of and do not rely on the golfer's ability to read the green, but instead, look only at the golfer's ability to aim at the desired target. Furthermore, the system described herein is rather inexpensive to build and set up and can be transported easily.
[0016] All patents and publications referenced or mentioned herein are indicative of the levels of skill of those skilled in the art to which the invention pertains, and each such referenced patent or publication is hereby incorporated by reference to the same extent as if it had been incorporated by reference in its entirety individually or set forth herein in its entirety. Applicants reserve the right to physically incorporate into this specification any and all materials and information from any such cited patents or publications. The specific methods and compositions described herein are representative of preferred embodiments and are exemplary and not intended as limitations on the scope of the invention. Other objects, aspects, and embodiments will occur to those skilled in the art upon consideration of this specification, and are encompassed within the spirit of the invention as defined by the scope of the claims. It will be readily apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. The invention illustratively described herein suitably may be practiced in the absence of any element or elements, or limitation or limitations, which is not specifically disclosed herein as essential. The methods and processes illustratively described herein suitably may be practiced in differing orders of steps, and that they are not necessarily restricted to the orders of steps indicated herein or in the claims. As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “a host cell” includes a plurality (for example, a culture or population) of such host cells, and so forth.
[0017] Under no circumstances may the patent be interpreted to be limited to the specific examples or embodiments or methods specifically disclosed herein. Under no circumstances may the patent be interpreted to be limited by any statement made by any Examiner or any other official or employee of the Patent and Trademark Office unless such statement is specifically and without qualification or reservation expressly adopted in a responsive writing by Applicants.
[0018] The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intent in the use of such terms and expressions to exclude any equivalent of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention as claimed. Thus, it will be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.
[0019] The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein. In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.
|
A putter fitting method and system comprising a laser configured to deflect a laser beam off of a putter at address and strike a scoring map in such a way so as to indicate the any error's in a golfer's aim. The method and system may further comprise determining physical alterations to the golfer's putter in order to correct the aim errors. Such changes may be to the hosels (neck), hosel offset, hosel types, head shape, loft, line combination, length or the like. These changes may be suggested automatically, for example, by a computer program, based on the location of the laser strike, or by a fitting professional.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 15/015,025, filed Feb. 3, 2016, entitled METHOD OF MAINTAINING PRINTHEADS USING WIPERS MOVING IN OPPOSITE DIRECTIONS, which is a continuation of U.S. application Ser. No. 14/712,742 filed on May 14, 2015, now issued U.S. Pat. No. 9,283,764, which is a continuation of U.S. application Ser. No. 14/473,806 filed on Aug. 29, 2014, now issued U.S. Pat. No. 9,061,531, which claims priority to U.S. Provisional Application No. 61/904, 983, filed Nov. 15, 2013, the contents of each of which are incorporated by reference herein for all purposes.
[0002] This application is related to U.S. application Ser. No. 14/473,811, filed Aug. 29, 2014, now issued U.S. Pat. No. 9,242,493, and to U.S. application Ser. No. 14/473,814, filed Aug. 29, 2014, now issued U.S. Pat. No. 9,193,194, the contents of each of which are incorporated by reference herein for all purposes.
FIELD OF THE INVENTION
[0003] This invention relates to a printer module and high-speed printers comprising one or more of such printer module(s). It has been developed for printing onto media webs, and particularly for use in conjunction with existing web feed mechanisms, such as those installed in offset printing presses.
BACKGROUND OF THE INVENTION
[0004] Inkjet printing is well suited to the SOHO (small office, home office) printer market. Increasingly, inkjet printing is expanding into other markets, such as label and wideformat printing. High-speed web printing is becoming a significant commercial sector for the inkjet printing market. High-speed inkjet web printing is especially competitive with traditional offset printing presses over relatively short print runs, because digital printing does not require the initial set-up time and cost of preparing offset printing plates. In a digital inkjet web printer, it is possible to print, for example, thousands of labels on-demand.
[0005] Hitherto, the present Assignee has described a number of inkjet web printers employing Memjet® pagewidth printing technology. Memjet® pagewidth printers employ one or more fixed printhead(s) while print media, such as a media web, are fed continuously past the printhead(s). This arrangement vastly increases print speeds compared to traditional scanning printhead technologies.
[0006] US 2011/0279530 (the contents of which are herein incorporated by reference) describes a benchtop web printer suitable for printing labels. The benchtop printer includes a single multi-color pagewidth printhead, an integrated web feed mechanism and a maintenance station. The maintenance station comprises individual liftable modules which cross the media feed path in order to perform printhead maintenance. A disadvantage of this arrangement is that a media web must be broken in order to perform printhead maintenance. This maintenance regime therefore places limitations on the types and lengths of print jobs that may be performed.
[0007] US 2012/0092419 (the contents of which are herein incorporated by reference) describes an industrial web printer comprised of a plurality of monochrome pagewidth printheads aligned with each other in a media feed direction. The printheads are mounted on a common housing connected to a scissor lift mechanism. The scissor lift mechanism enables the printheads to be lifted and lowered relative to the media web. In order to perform printhead maintenance, the printheads are lifted, a maintenance assembly is slid laterally underneath the printheads and the printheads lowered onto the maintenance assembly. In this way, printhead maintenance may be performed without breaking the media web. However, a disadvantage of the printer described in US 2012/0092419 is its relatively high cost as well as difficulties in scaling the printer for printing onto wider media widths.
[0008] US 8,485,656 (the contents of which are herein incorporated by reference) describes a wide format printer comprising a plurality of staggered overlapping printheads. Each printhead is maintained by a respective rotatable maintenance carousel positioned opposite its respective printhead. Each carousel crosses the media path in order to perform printhead maintenance, which necessitates breaking the media web.
[0009] It would be desirable to provide a relatively low-cost, high-speed inkjet web printer, which does not require breaking the media web in order to perform printhead maintenance. It would further be desirable to provide an inkjet web printer, which is readily scalable to wider media widths (e.g. widths greater than about 210 mm). It would further be desirable to provide a high-speed inkjet web printer, which is amenable to retrofitting into existing web feed arrangements, such as those used in offset printing presses. Such a retrofitted printer is an attractive proposition for commercial printing presses having a number of offset printing lines and, moreover, promotes uptake of digital web printing at a relatively low cost.
SUMMARY OF THE INVENTION
[0010] In a first aspect, there is provided a modular printer comprising:
[0000] (a) a media feed path defining a media feed direction;
(b) a first printer module suspended over the media feed path, the first printer module comprising:
[0011] a first printhead extending transversely with respect to the media feed direction;
[0012] a first maintenance sled positioned at a first side of the first printhead relative to the media feed direction, the first maintenance sled being slidable towards the first printhead parallel with the media feed direction;
[0000] (c) a second printer module suspended over the media feed path and at least partially overlapping the first printer module in the media feed direction, the second printer module comprising:
[0013] a second printhead extending transversely with respect to the media feed direction, the second printhead at least partially overlapping the first printhead in the media feed direction; and
[0014] a second maintenance sled positioned at an opposite second side of the second printhead relative to the media feed direction, the second maintenance sled being slidable toward the second printhead parallel with the media feed direction,
[0000] wherein the first and second printheads are relatively proximal to each other with respect to the media feed direction, and the first and second maintenance assemblies are relatively distal from each other with respect to the media feed direction.
[0015] As used herein, the term “printhead” generally refers to a non-traversing printhead which is stationary during printing, as opposed to conventional scanning printheads which traverse across the media path printing in swathes.
[0016] The modular printer according to the first aspect advantageously enables printing onto relatively wide media webs using a readily scalable arrangement of first and second printer modules. In principle, the range of printable media widths is virtually limitless, simply by placing the first and second printer modules in an alternating overlapping arrangement across the media feed path.
[0017] In this modular arrangement, the width of the print zone is minimized by placing the printheads relatively proximal and the maintenance stations relatively distal. This arrangement maximizes print quality whilst enabling a versatile maintenance regime. Typically, a distance between the first and second printheads in the media feed direction is from 10 to 200 mm or from 20 to 100 mm. Correspondingly, the width of the print zone is in the range of 10 to 200 mm or 20 to 100 mm. The width of the print zone is defined in a direction parallel to the media feed direction.
[0018] Preferably, the first and second maintenance assemblies are configured to move in opposite directions—that is, towards each other and towards respective first and second printheads. In other words, the first maintenance sled may move in the same direction as the media feed direction, while the second maintenance sled moves in the opposite direction. Alternatively, the first maintenance sled may move in an opposite direction to the media feed direction, while the second maintenance sled moves in the same direction as the media feed direction.
[0019] Preferably, the first and second printheads are each mounted in a respective printhead cartridge, which may be user-replaceable. The printhead cartridge may comprise, for example, ink couplings and an ink feed arrangement in addition to the printhead. The printheads may be multi-color printheads or monochrome printheads.
[0020] Preferably, the printhead cartridges are identical and replaceable in each of the first and second printer modules. Providing identical, replaceable printhead cartridges in the first and second printer modules minimizes printhead cartridge production costs and is convenient for end-users.
[0021] The first and second printer modules may be the same or different from each other. Identical first and second printer modules have the advantage of reducing production costs of the printer modules. However, identical first and second printer modules require the same relative orientation of the printhead cartridge and the maintenance station. Since printheads typically have asymmetrical color planes with respect to the media feed direction, identical first and second printer modules require printhead cartridges in the first printer module to print “forwards” (e.g. CMYK) and printhead cartridges in the second printer modules to print “backwards” (e.g. KYMC). Although such a configuration is technically possible using appropriate controller firmware, in practice it is difficult to ensure consistent print quality across the media width when some printheads are printing “forwards” and some printheads are printing “backwards”. For example, the different effects of overprinting and underprinting are difficult to compensate when the color plane order is reversed.
[0022] Therefore, the printhead cartridges are preferably all oriented identically with respect to the media feed direction, such that all printheads print with the same color plane sequence. The corollary is that the first and second printer modules are preferably non-identical by virtue of the different orientations of the printheads relative to the maintenance assemblies in the first and second printer modules.
[0023] Preferably, the first and second printer modules comprise respective lift mechanisms for lifting a respective printhead cartridge relative to the media feed path. Lifting the printhead cartridges relative to the media feed path enables the printheads to be maintained without breaking the media web.
[0024] Preferably, the first and second printer modules each comprise a respective print bar carriage, the print bar carriage being slidably received within the housing and liftable relative to the housing.
[0025] Preferably, each print bar carriage carries a respective printhead cartridge.
[0026] Preferably, each print bar carriage carries a respective ink manifold, the ink manifold having at least one coupling for mating with and supplying ink to a respective printhead cartridge.
[0027] Preferably, in the first aspect, the print zone has a length greater than 216 mm and up to about 2000 mm, the length of the print zone being defined in a direction transverse to the media feed direction. In some embodiments, the print zone has a length greater than 300 mm, greater than 400 mm or greater than 500 mm. Hence, the modular printer is capable of printing onto wideformat media—that is media wider than standard A4 or US letter-sized media.
[0028] The first and second printer modules may be fixedly mounted to, for example, a gantry suspended over the media feed path. Typically, the first and second printer modules comprise rigid mounting beams configured for mounting the printer modules over the media feed path.
[0029] In a second aspect, there is provided a printer assembly comprising:
[0030] a housing comprising a pair of opposite sidewalls, each sidewall defining a respective referencing slot;
[0031] a pair of first stops, each first stop being positioned towards a lower end of a respective referencing slot defined in a respective sidewall of the housing, each first stop defining a first datum surface;
[0032] a print bar carriage slidably received within the housing, the print bar carriage comprising:
a chassis; a printhead supported by the chassis; and a pair of lugs, each lug extending outwardly from opposite sides of the chassis, each lug being received in a respective referencing slot of the housing, and each lug being slidably movable within its respective referencing slot; and
[0036] a lift mechanism for lifting the print bar carriage relative to the housing,
[0000] wherein the first datum surfaces define a printing position of the print bar carriage, the print bar carriage being in the printing position when each lug is in abutting engagement with its respective first datum surface.
[0037] The printer assembly according to the second aspect advantageously enables the printing position of the liftable print bar carriage to be defined with reference to a housing in which the print bar carriage is slidably received. In particular, the lugs, referencing slots and stops provide a compact design without any special modifications required to the printhead. Each of the printer modules described in connection with the first aspect may comprise a printer assembly according to the second aspect.
[0038] Typically, the stops have adjustable heights enabling facile user adjustment of the printing position height (e.g. for use with different media thicknesses) without requiring internal access to each printer assembly. Once the printer assembly has been installed by suspending over a media feed path (e.g. by mounting to a rigid overhead cantilever beam or gantry), the stops may then be used to control the height of the printing position relative to the media and, hence, the “pen-to-paper spacing” (PPS) or “throw distance” of ejected ink droplets.
[0039] Preferably, the printhead is mounted between opposite side panels of the chassis and each lug extends outwardly from a respective side panel.
[0040] Preferably, each first stop is mounted to an outer (external) surface of a respective sidewall of the housing. Externally mounted stops avoid any interference between the datum referencing for the printhead and a sliding maintenance sled for maintaining the printhead. Furthermore, externally mounted stops facilitate user accessibility in situ when the printer assembly is installed.
[0041] Preferably, each first stop is adjustably mounted relative to its respective sidewall to provide a plurality of different printing positions. Suitable means for providing adjustable mounting of each first stop will be readily apparent to the person skilled in the art. For example, a slider mechanism or a screw mechanism may be used for manual stop height adjustment. Alternatively, a range of predetermined stop heights may be provided using one or more detents in combination with a slider mechanism, as is known in the art.
[0042] Preferably, the housing comprises one or more upper mounting plates or beams for fixedly mounting the printer assembly on a support, so as to suspend the printer assembly over a media path.
[0043] Preferably, the lift mechanism comprises a rack and pinion mechanism.
[0044] Preferably, the carriage comprises a pair of racks and a shaft is rotatably mounted between the sidewalls of the housing, wherein a pair of pinions are fixedly mounted about the shaft, each pinion being engaged with a respective rack.
[0045] Preferably, the housing defines a guide slot engaged with part of the carriage, said guide slot constraining movement of the carriage relative to the housing.
[0046] Preferably, the guide slot is laterally spaced from one of the referencing slots and extends parallel therewith.
[0047] Preferably, a first sidewall of the housing has a respective guide slot and the carriage comprises a plurality of rotatably mounted first bearings, each first bearing travelling within the guide slot.
[0048] Preferably, the plurality of first bearings are rotatably mounted to a bracket fixed to a side panel of the chassis.
[0049] Preferably, the first bearings are aligned with each other and parallel with the racks.
[0050] Preferably, the printer assembly further comprises:
a track fixed to the housing, the track extending transversely with respect to the referencing slots; a maintenance sled mounted on the track; a transport mechanism for transporting the maintenance sled along the track; and a controller for coordinating the lift mechanism and the transport mechanism, the controller being configured to provide:
the printing position in which the maintenance sled is laterally displaced out of alignment with the printhead; and a maintenance position in which at least part of the maintenance sled is aligned with the printhead,
wherein the printhead is raised in the maintenance position relative to the printing position.
[0057] The printer assembly may be configured into the maintenance position (e.g. a capping position of a wiping position) by lifting the print bar using the lift mechanism, transporting the maintenance sled parallel with the media feed direction towards the printhead, and lowering the print bar such that the printhead is engaged with a suitable maintenance module (e.g. capper or wiper). The printer assembly may be configured into the printing position by lifting the print bar using the lift mechanism, transporting the maintenance sled away from the printhead, and lowering the print bar such that the printhead is in the printing position, the printing position being lower than the maintenance position.
[0058] Preferably, the maintenance sled comprises at least one of:
a capper module for capping the printhead; and a wiper module for wiping the printhead.
[0061] Preferably, the capper module comprises a pair of second stops disposed at either end of a perimeter capper, each second stop defining a second datum surface.
[0062] Preferably, landing zones are defined at either longitudinal end of the printhead for abutting engagement with the second datum surfaces in a capping position.
[0063] As described in US 2011/0279524, the contents of which are herein incorporated by reference, the perimeter capper may comprise an internal wick element positioned for capturing ink during spitting and/or priming operations. The wick element is placed accurately in close proximity with (but not in contact with) the printhead, such that a fluidic bridge (“ink bridge”) can form between the printhead and the wicking element. Accordingly, the second datum surfaces and landing zones are employed for accurate positioning of the perimeter capper, which is preferably of the type described in US 2011/0279524.
[0064] Preferably, the wiper module is resiliently mounted on the maintenance sled. Resilient mounting of the wiper module allows a degree of tolerance in the positioning of the printhead relative to the wiper in a wiping position. Typically, the wiping position is less critical than the capping position and may be controlled using suitable sensors and/or timers on the lift mechanism, rather than via datums.
[0065] Preferably, the wiper module comprises a rotatably mounted wiper roller, the wiper roller being coextensive with the printhead. A suitable maintenance sled comprising a wiper roller and perimeter capper, which may be adapted for use in connection with the present printer assembly, is described in US 2012/0092419, the contents of which are incorporated herein by reference.
[0066] In a third aspect, there is provided a printer assembly comprising:
[0067] a housing comprising a pair of opposite first and second sidewalls extending along a nominal x-axis, the first sidewall having a guide slot extending along a z-axis, the guide slot being defined between opposite first bearing surfaces;
[0068] a shaft rotatably mounted between the sidewalls, the shaft extending along ay-axis;
[0069] first and second pinions fixedly mounted at either end of the shaft for rotation therewith;
[0070] a print bar carriage slidably received within the housing, the print bar carriage comprising:
a chassis; first and second parallel racks fixed to the chassis, each rack being engaged with a respective pinion to define a rack-and-pinion lift mechanism; a set of first bearings rotatably mounted at a first side of the chassis, each first bearing being received in the guide slot; and a printhead supported by the chassis; and
[0075] a drive motor operatively connected to the shaft for rotating the shaft and thereby lifting the print bar carriage relative to the housing along the z-axis via the rack-and-pinion lift mechanism,
[0000] wherein, during sliding movement of the print bar carriage, the set of first bearings travels within the guide slot and bear against the first guide surfaces to constrain rotational movement of the print bar carriage.
[0076] The printer assembly according to the third aspect advantageously provides a rigid framework for raising and lowering the print bar carriage with highly accurate positioning. In particular, cooperation of the first bearings with the guide slot of the rigid housing provides excellent constraint of undesirable printhead rotation. Each of the first and second printer modules described in connection with the first aspect may comprise a printer assembly according to the third aspect.
[0077] Raising and lowering a print bar introduces significant rotational forces due to the intrinsic moment of the print bar about the lift axis. By way of contrast, U.S. Pat. No. 8,353,566 describes a rack-and-pinion lift mechanism whereby a pair of brackets are slidably mounted on a complementary pair of guide posts. Each bracket has a rack connected to a print bar enabling the print bar to be raised and lowered via rotation of a shaft having a pair of pinions engaged with the racks. A disadvantage of the lift mechanism described in U.S. Pat. No. 8,353,566 is that the elongate guide posts inevitably lack true parallelism, which is problematic for printhead positioning as well as operation of the lift mechanism. U.S. Pat. No. 8,353,566 attempts to address this problem by allowing a degree of play in the bracket mountings and relying solely on datums in the lowered position for correcting misalignments in theta y during lifting/lowering. However, the prior art arrangement inevitably results in undue wearing of the lift mechanism and, moreover, does not ensure accurate positioning of the printhead in the printing position. The printer assembly according to the third aspect ensures smooth lifting and lowering of the printhead with minimal wear and accurate printhead placement in the printing position.
[0078] Preferably, the carriage comprises a second bearing rotatably mounted to an inner surface of the second sidewall, wherein the second bearing bears against a second bearing surface of the print bar carriage, said second bearing surface extending along the z-axis. The first and second bearings, therefore, cooperate to constrain rotational movement of the print bar carriage in theta z as well as theta y.
[0079] Preferably, the second bearing surface is defined by a non-toothed surface of the second rack. Typically, the non-toothed surface is opposite a toothed surface of the second rack, the toothed surface being intermeshed with the second pinion.
[0080] Preferably, the shaft and pinions cooperate with the parallel racks to constrain rotational movement of the print bar about the x-axis. Thus, the print bar carriage is preferably constrained in theta x, theta y and theta z during lifting and lowering.
[0081] Preferably, the chassis comprises first and second opposite side panels, the set of first bearings being rotatably mounted to a bracket fixed to the first side panel of the chassis.
[0082] Preferably, the housing comprises a track extending transversely with respect to the referencing slots, wherein the printer assembly further comprises:
[0083] a maintenance sled mounted on the track;
[0084] a transport mechanism for transporting the maintenance sled along the track; and
[0085] a controller for coordinating the lift mechanism and the transport mechanism, the controller being configured to provide:
the printing position in which the maintenance sled is laterally displaced out of alignment with the printhead; and a maintenance position in which at least part of the maintenance sled is aligned with the printhead,
wherein the printhead is raised in the maintenance position relative to the printing position.
[0088] Preferably, the transport mechanism comprises an endless drive belt tensioned about a plurality of pulleys, the maintenance sled being attached to the drive belt for movement therewith.
[0089] Preferably, the bracket is configured to avoid contact with the drive belt in the printing position. Preferably, the bracket is L-shaped or U-shaped.
[0090] Preferably, each sidewall of the housing comprises a pair of first stops, each first stop defining a first datum surface, each first stop being positioned towards a lower end of a respective referencing slot defined in each sidewall, each referencing slot being laterally spaced from and parallel with the guide slot; and
[0091] the print bar carriage comprises a pair of lugs, each lug extending outwardly from opposite sides of the chassis, each lug being received in a respective referencing slot of the housing, and each lug being slidably movable within its respective referencing slot,
[0000] wherein the first datum surfaces define a printing position of the print bar carriage, the print bar carriage being in the printing position when each lug is in abutting engagement with its respective first datum surface.
[0092] Preferably, the print bar carriage comprises a chassis having opposite side panels, the printhead being mounted between the side panels, and wherein each lug extends outwardly from a respective side panel.
[0093] Preferably, each first stop is mounted to an outer surface of a respective sidewall of the housing.
[0094] Preferably, each first stop is adjustably mounted relative to its respective sidewall to provide a plurality of different printing positions.
[0095] Preferably, the maintenance sled comprises at least one of: a capper module for capping the printhead; and a wiper module for wiping the printhead.
[0096] Preferably, the capper module comprises a pair of second stops disposed at either end of a perimeter capper, each second stop defining a second datum surface.
[0097] Preferably, landing zones are defined at either longitudinal end of the printhead for abutting engagement with the second datum surfaces in a capping position.
[0098] Preferably, the wiper module is resiliently mounted on the maintenance sled.
[0099] Preferably, the wiper module comprises a rotatably mounted wiper roller, the wiper roller being coextensive with the printhead.
[0100] It will be appreciated that preferred and other embodiments described herein may be applicable to any one or more of the first, second and third aspects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0101] Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:
[0102] FIG. 1 is a perspective of a printer module according to the present invention;
[0103] FIG. 2 is a perspective of the printer module with mounting beams removed;
[0104] FIG. 3 is a perspective of the printer module configured in a printing position with mounting beams removed;
[0105] FIG. 4 is a perspective of the printer module configured in a maintenance position with mounting beams removed;
[0106] FIG. 5 is an exploded perspective of the printer module;
[0107] FIG. 6 is a perspective of a print bar carriage;
[0108] FIG. 7 is an exploded perspective of the print bar carriage;
[0109] FIG. 8 is schematic system control block diagram;
[0110] FIG. 9 is a perspective of the printer module in a printing position with mounting beams, a housing sidewall and print bar chassis side panels removed;
[0111] FIG. 10 is a side view showing engagement of a guide slot with first bearings in a raised position;
[0112] FIG. 11 is a side view showing engagement of a guide slot with first bearings in a printing position;
[0113] FIG. 12 is a top plan view of the printer module with mounting beams removed;
[0114] FIG. 13 is a perspective of the printer module in a maintenance position with mounting beams, a housing sidewall and print bar chassis side panels removed;
[0115] FIG. 14 is a rear view of a printhead cartridge and maintenance sled;
[0116] FIG. 15 is a perspective of the maintenance sled;
[0117] FIG. 16 is a perspective of the maintenance sled and transport mechanism;
[0118] FIG. 17 is a perspective of the maintenance sled and transport mechanism with drive belt removed; and
[0119] FIG. 18 is a top plan view of a modular printer according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Printer Module Overview
[0120] Referring to FIG. 1 , there is shown a printer assembly in the form of a printer module 1 comprising a housing 10 having a first sidewall 12 and an opposite second sidewall 14 . The first and second sidewalls 12 and 14 are connected via upper mounting beams 15 and 17 , and lower connecting beams 19 and 21 to provide a rigid framework for housing a print engine comprised of a print bar carriage 100 and maintenance sled 200 (see FIG. 5 ). Each of the mounting beams 15 and 17 has mounting fixtures 18 for mounting the printer module 1 to a gantry or cantilever beam (not shown). Thus, the printer module 1 is configured for suspending over a print media path. Print media, such as a media web, may be fed past the printer module 1 using, for example, suitable feed rollers as is known in the art. The housing 10 has no base to facilitate feeding of the media web past a lower portion of the printer module 1 .
[0121] The print bar carriage 100 is slidably received within the housing 10 enabling lifting and lowering of the print bar carriage relative to the housing 10 using a lift mechanism. As shown in FIGS. 1 and 2 , the print bar carriage 100 is raised in a transition position; as shown in FIG. 3 , the print bar carriage 100 is lowered in a printing position; and as shown in FIG. 4 , the print bar carriage 100 is raised in a maintenance position.
[0122] Referring briefly to FIGS. 6 and 7 , the print bar carriage 100 comprises an ink manifold 101 and printhead cartridge 102 , such as a replaceable Memjet® printhead cartridge, mounted on a chassis 104 for printing onto print media in a single pass. (For a detailed description of the printhead cartridge 102 , reference is made to U.S. Pat. Nos. 8,540,353; 8,025,383 and 7,845,778, the contents of which are incorporated herein by reference). The ink manifold 101 is configured for supplying ink to and receiving ink from the printhead cartridge 102 via a pair of couplings, such as the couplings described in U.S. Pat. No. 8,540,353, the contents of which are herein incorporated by reference. The ink manifold 101 forms part of an ink delivery system (not shown) in fluid communication with the printhead 105 . The printhead cartridge 102 comprises a printhead 105 mounted to a lower surface thereof ( FIG. 14 ), which requires periodic maintenance. Maintenance may be required to wipe nozzles free of ink and debris, to unblock nozzles which have become blocked with ink or to minimize evaporation of ink by capping the printhead 105 .
[0123] Referring to FIGS. 2 to 4 , the maintenance sled 200 is slidable along a nominal x-axis of the printer module 1 using a transport mechanism (described below), the x-axis being defined as an axis parallel to a media feed direction. Maintenance modules in the form of a capper module 202 and a wiper module 204 are mounted on the maintenance sled 200 for performing respective capping and wiping operations on the printhead.
[0124] In order to perform a capping or wiping operation, the print bar carriage 100 is raised to its transition position ( FIGS. 1 and 2 ), the maintenance sled is moved along the x-axis so as to be positioned below the printhead 105 , and the print bar carriage lowered onto either the capper module 202 or the wiper module 204 ( FIG. 4 ). Of course, the precise positioning of the maintenance sled 200 relative to the printhead 105 will depend on whether a capping or wiping operation is being performed. Generally, the printhead 105 is maintained in a capped state during idle periods.
[0125] In order to perform printing, the print bar carriage 100 is raised to its transition position and the maintenance sled 200 is laterally displaced to one side of the printhead 105 by slidably moving the maintenance sled along the x-axis ( FIGS. 1 and 2 ). Once the maintenance sled 200 has been laterally displaced from the printhead 105 , the print bar carriage 100 is lowered to a printing position ( FIG. 3 ), which is the lowest position of the print bar carriage.
[0126] Referring to FIG. 8 , a controller 500 is employed to coordinate various operations of a media feed mechanism 501 ; an ink delivery system 502 which delivers ink to the printhead; a print bar system 503 comprising the print bar carriage 100 , printhead 105 and lift mechanism; and a maintenance system 504 comprising the maintenance sled 200 , transport mechanism and maintenance modules. The ink delivery system 502 may be of the type described in U.S. Pat. No. 8,485,619, the contents of which are incorporated herein by reference. For example, the ink delivery system 502 may be a circulatory system having an ink container, which delivers ink to inlet ports 105 of the printhead cartridge 102 and receives ink from outlet ports 107 of the printhead cartridge. Various printing, purging, pressure priming and depriming operations may be coordinated via a pump and valve arrangement of the ink delivery system, as described in U.S. Pat. No. 8,485,619. However, it will of course be appreciated that other ink delivery systems may be used, as known in the art. The controller 500 coordinates all maintenance and printing operations via suitable signal communication with the ink delivery system 502 and maintenance system 504 , as well as the print bar system 503 and media feed mechanism 501 .
Lift Mechanism
[0127] The print bar carriage 100 is slidably liftable relative to the housing 10 (along a nominal z-axis) using a rack-and-pinion lift mechanism. Referring initially to FIG. 7 , the rack-and-pinion lift mechanism comprises first and second toothed racks 110 and 112 fixedly mounted to respective first and second side panels 114 and 116 of the chassis 104 . The chassis 104 further comprises an end panel 118 and a base panel 120 interconnecting the side panels 114 and 116 to provide a rigid framework which ensures parallelism of the side panels and, therefore, parallelism of the racks 110 and 112 mounted to the side panels. As best shown in FIGS. 3, 5 and 9 , a shaft 25 is rotatably mounted between the sidewalls 12 and 14 of the housing 10 . First and second toothed pinions 26 and 28 are fixedly mounted about the shaft 25 at opposite ends thereof for rotation with the shaft. The first and second pinions 26 and 28 are intermeshed with respective first and second racks 110 and 112 to provide the rack-and-pinion lift mechanism.
[0128] Rotation of the shaft 25 is driven by a lift motor 30 , which is engaged with the shaft via a worm gear arrangement. The worm gear arrangement comprises a worm 32 connected to the lift motor 30 and an intermeshing worm wheel 34 mounted about the shaft 25 adjacent the second pinion 28 ( FIG. 9 ). Hence, the lift motor 30 is used to rotate the 25 shaft in either direction to perform either lifting or lowering of the print bar carriage 100 via the rack-and-pinion lift mechanism.
Constraint of Print Bar Carriage Movement
[0129] As described above, the print bar carriage 100 is lifted and lowered by actuation of the lift motor 30 operatively connected to the rack-and-pinion lift mechanism. In order to provide a smooth and reliable lift mechanism, it is preferable to constrain any rotational movement of the print bar carriage about the y-axis of the printer module 1 . As viewed in FIG. 10 , the print bar carriage 100 experiences a clockwise rotational biasing force about the pinion 26 due to the weight of the print bar carriage 100 indicated by arrow W.
[0130] In order to constrain any rotational movement, a pair of first bearings 150 A and 150 B are rotatably mounted to the first side panel 114 of the chassis 104 via a mounting bracket 152 . The first bearings 150 A and 150 B are received in a guide slot 47 defined by the first sidewall 12 of the housing 10 and a guide bracket 49 fixed to an outer surface of the first sidewall 12 . The guide slot 47 extends along the z-axis of the printer module 1 and is laterally displaced from a referencing slot 40 (described below) extending parallel therewith.
[0131] The guide bracket 49 defines a pair of opposite first bearing surfaces 50 A and 50 B extending along opposite longitudinal sides of the guide slot 47 . The first bearing surfaces 50 A and 50 B provide a reaction force to the intrinsic rotational bias of the print bar carriage 100 . The first bearings 150 A and 150 B, aligned parallel with the guide slot 47 , travel within the guide slot along the z-axis and bear against respective bearing surfaces 50 A and 50 B during lifting and lowering of the print bar carriage 100 . In practice, a marginal degree of clearance (e.g. 0.01 to 0.1 mm) between the first bearings and the first bearing surfaces allows the upper first bearing 150 A to bear against the right-hand first bearing surface 50 A and the lower first bearing 150 B to bear against the left-hand first bearing surface 50 B (as viewed in FIG. 10 ) with the rotational bias of the print bar carriage 100 .
[0132] FIG. 11 is a side view of the first bearings 150 and guide slot 47 when the print bar carriage 100 is in its lowermost printing position. With the print bar carriage 100 supported by the first stops 36 in this lowermost position, the rotational bias of the print bar carriage is reversed.
[0133] Referring to FIGS. 12 and 13 , a second bearing 60 is rotatably mounted to an inner surface of the second sidewall 14 of the housing 10 via a mounting block 62 . The second bearing 60 is positioned to bear against a non-toothed surface of the second rack 112 . The non-toothed surface is opposite the toothed surface of the second rack 112 and defines a second bearing surface 155 for the second bearing 60 to bear against during lifting and lowering of the print bar carriage 100 . FIG. 13 has the second sidewall 14 and second side panel 116 removed to show the engagement of the second bearing 60 with the second bearing surface 155 more clearly.
[0134] The first bearings 150 and the second bearing 60 cooperate with their respective first bearing surfaces 50 and second bearing surface 155 to constrain rotational movement of the print bar carriage 100 about the y- and z-axes (theta y and theta z) during lifting and lowering. This constraint of rotational movement minimizes any undue wearing of the rack-and-pinion mechanism upon repeated lifting and lowering of the print bar carriage 100 .
Datum Arrangements
[0135] Referring to FIGS. 1 to 4 , the printing position of the print bar carriage 100 is defined by a pair of first stops 36 mounted to the outer surfaces of the first and second sidewalls 12 and 14 . Each of the first stops 36 is positioned towards a lower end of respective referencing slots 40 defined in respective sidewalls 12 and 14 of the housing 10 . The chassis 104 has a pair of lugs 130 extending outwardly from respective side panels 114 and 116 , and the lugs are received in respective referencing slots 40 of the housing 10 . The lugs 130 are slidably movable along the z-axis within their respective referencing slots 40 . The first stops 36 define respective first datum surfaces 37 for abutting engagement with respective lugs 130 in the printing position ( FIG. 3 ). When each of the lugs 130 has been lowered into abutting engagement with its respective abutment surface 37 , the print bar carriage 100 is in its printing position.
[0136] During lifting and lowering, the print bar carriage 100 may bow in the z-axis, causing one of the lugs to engage with its respective abutment surface before the other lug. In order to accommodate potential bowing of the print bar carriage 100 , the controller 500 receives feedback from the lift motor 30 —when the lift motor experiences a sharp increase in resistance, corresponding to one of the lugs engaging with its respective abutment surface, the controller instructs the motor to continue for a predetermined period to ensure that the other lugs also engages with its respective abutment surface. In this way, seating of the print bar carriage 100 in its printing position is ensured with each lowering operation.
[0137] The first stops 36 are each slidably mounted to respective sidewalls 12 and 14 to provide adjustable printing positions. Accordingly, after installation of the printer module 1 , users are able to adjust the printing position of the printhead in order to optimize print quality, for example, when printing onto different media thicknesses. Each of the stops 36 is secured into position, after sliding adjustment of the stop, via a respective pair of locking screws 45 .
[0138] The printing position of the print bar carriage 100 is critical for controlling the throw distance of ejected ink droplets (otherwise known in the art as the “pen-to-paper spacing” (PPS)) and, as described above, the first datum surfaces 37 provide accurate control of this distance in combination with the lugs 130 attached to the chassis 104 .
[0139] Since the capper module 202 typically comprises an internal wick element (not shown), which should be positioned in close proximity to but not touching the printhead 105 during capping (see US2011/0279524, the contents of which are incorporated herein by reference), it is important to control the printhead-capper distance when the print bar carriage 100 is positioned in the capping position.
[0140] Referring to FIG. 14 , the capper module 202 comprises a perimeter capper 210 , extending a length of the printhead 105 , having resiliently deformable sidewalls defining an internal cavity. The capper module 202 further comprises a pair of seconds stops 212 positioned at either end of the perimeter capper 210 . The second stops 212 define respective second datum surfaces 214 for abutting engagement with respective landing zones 215 defined by the printhead cartridge 102 at either end of the printhead 105 . When the print bar carriage 100 is lowered into the capping position ( FIG. 4 ), the landing zones 215 abut with the second datum surfaces 214 to define the capping position.
[0141] Hence, the printing position of the print bar carriage 100 is controlled by abutting engagement of the lugs 130 with the first datum surfaces 37 ; and the capping position of the print bar carriage 100 is controlled by abutting engagement of the landing zones 215 with the second datum surfaces 214 .
Maintenance Sled and Transport Mechanism
[0142] As described above in connection with FIGS. 1 to 4 , the maintenance sled 200 is slidable towards and away from the printhead 105 in a direction parallel with the media feed direction. Referring to FIG. 15 , the maintenance sled comprise a sled frame 201 on which is mounted the capper module 202 and the wiper module 204 (collectively known herein as “maintenance modules”).
[0143] As described above the capper module 202 is fixedly mounted to the sled frame 201 , while the wiper module 204 is resiliently mounted to the sled frame via coil springs 217 , which bias the wiper module towards the printhead 105 during wiping operations. The wiper module 204 comprises a wiper roller 218 having a microfiber surface, which is configured to wipe ink and debris from the printhead 105 when rotated or translated in contact therewith. A metal transfer roller (not shown in FIG. 15 ) is in permanent contact with the microfiber wiper roller 218 to receive ink carrying entrained debris from the wiper roller. For a more detailed description of the wiper module, reference is made to US 2012/0092419, the contents of which are incorporated herein by reference.
[0144] The distance between the wiper roller 218 and the printhead 105 during wiping is less critical than the capping distance. Accordingly, the biasing of the wiper module 204 via the springs 217 is sufficient to provide a suitable wiping force without accurate control of the printhead position during wiping operations.
[0145] The maintenance sled 200 is slidably mounted between the sidewalls 12 and 14 of the housing 10 to enable sliding movement along the x-axis of the printer module 1 . Referring briefly to FIG. 5 , a sled guide 65 is fixedly mounted to an inner surface of the second sidewall 14 and extends along the x-axis. The sled guide 65 receives a set of sled bearings 222 rotatably mounted to a second side of the sled frame 291 .
[0146] Turning to FIGS. 16 and 17 , a rail 67 is fixedly mounted to an inner surface of the first sidewall 12 and extends along the x-axis. A sled carriage 69 is slidably mounted on the rail 67 for movement therealong. The sled carriage 69 is connected to a sled mount 224 fixed to the sled frame 201 . Hence, the maintenance sled 200 is slidable along a track defined by the sled guide 65 and the rail 67 .
[0147] Movement of the sled carriage 69 along the rail 67 is driven by a transport mechanism comprised of a transport motor 70 operatively connected to a drive pulley 72 , and an endless drive belt 73 tensioned between the drive pulley 72 and idler pulleys 74 A, 74 B and 74 C. A first idler pulley 74 A is mounted to the first sidewall 12 at one end of the rail 67 , while second and third idler pulleys 74 B and 74 C are mounted to the first sidewall 12 at the other end of the rail 67 . The idler pulleys 74 A, 74 B and 74 C serve to steer the drive belt 73 between the two ends of the rail 67 and around the drive pulley 72 .
[0148] As shown in FIG. 16 , the drive belt 73 has a toothed inner surface engaged with the sled mount 224 . Thus, movement of the drive belt 73 , driven by the transport motor 70 , causes the maintenance sled 200 to move along the x-axis of the printer module 1 , either towards or away from the print bar carriage 100 .
Modular Printer Comprising Array of Printer Modules
[0149] Referring to FIG. 18 , and having described the printer module 1 in detail, there is shown in plan view a modular printer 600 comprising three printer modules A, B and C arranged in a staggered overlapping array. The printer modules A, B and C are mounted to a gantry (not shown) extending over a media web 602 so that each printer module is suspended over the web. The media feed direction is indicated by the arrow M. With this staggered overlapping arrangement, it is possible to print onto relatively wide media widths; in principle, the modular printer 600 may comprise any number of printer modules from, for example, 2 to 10 modules.
[0150] Each printer module overlaps with at least one neighboring printer module in the media feed direction M With suitable timing and control of nozzle firing in each printer module, an image may be printed seamlessly onto the web 602 using each of the overlapping modules. An analogous arrangement of staggered overlapping printheads, albeit with a different maintenance arrangement, was described in U.S. Pat. No. 8,485,656, the contents of which are incorporated herein by reference.
[0151] In the modular arrangement shown in FIG. 18 , the printer modules A, B and C are oriented such that the printhead cartridges 102 are relatively proximal to each other and the maintenance sleds 200 relatively distal from each other with respect to the media feed direction. In other words, the middle printer module B has it orientation reversed compared to the two outer printer modules A and C. This arrangement positions the printheads 105 in relatively close proximity and, therefore, minimizes the width of the print zone. (As used herein, the width of the print zone is defined parallel with the media feed direction, while the length of the print zone is defined perpendicular to the media feed direction). Thus, in order to perform maintenance on all printer modules simultaneously, the maintenance sled 200 of printer module B moves in an opposite direction to the maintenance sleds 200 of printer modules A and C. In other words, all maintenance sleds 200 move towards the print zone in order to perform maintenance operations on their respective printheads 105 . This arrangement of printer modules enables high print quality by minimizing the width of the print zone and, furthermore, enables printhead maintenance without breaking the media web 602 .
[0152] Still referring to FIG. 18 , it should be noted that printer module B is similar, but not identical to printer modules A and C. Printer modules A and C are identical to the printer module 1 described above and has the ink manifold 101 relatively proximal to the maintenance sled 200 in the printing position, as shown. However, printer module B is subtly different than printer modules A and C inasmuch as the ink manifold 101 of printer module B is relatively distal from the maintenance sled 200 in the printing position, as shown. This subtle difference enables all printhead cartridges 102 , and thereby all printheads 105 , to be oriented identically with respect to the media feed direction M. Accordingly, all printheads 105 , having a predetermined order of color channels, print in the same directional sense and the same firing order of color channels. Therefore, any print artifacts arising from overprinting or underprinting during multi-color printing are minimized.
[0153] It will, of course, be appreciated that the present invention has been described by way of example only and that modifications of detail may be made within the scope of the invention, which is defined in the accompanying claims.
|
A method of wiping a plurality of printheads positioned in a staggered overlapping arrangement across a width of a media feed path, each printhead having a respective wiper associated therewith. The wipers for neighboring printheads are moved in opposite directions with respect to each other.
| 1
|
This application claims the benefit of U.S. Provisional Application No. 60/035,506, filed Jan. 15, 1997.
BACKGROUND
This invention relates to bruxism measurement devices and more particularly to an intraoral appliance for quantifying the extent of wear due to the grinding action of teeth.
Bruxism has generally been defined as the nonfunctional clenching, grinding, gritting, gnashing, and clicking of the teeth. Bruxism can occur while a person is awake or asleep. When the phenomenon occurs during sleep, it is called nocturnal bruxism. Even when it occurs during waking hours, the bruxist is often not conscious of the activity. Biting force exerted during bruxism often significantly exceeds peak biting force exerted during normal chewing. Biting forces exceeding 700 pounds have been measured during bruxing events. Chronic bruxism may result in musculoskeletal pain, headaches, and damage to the teeth and/or the temporomandibular joint.
The symptoms of bruxism include: clicking or grinding noises detected by a sleeping partner, wear facets on a bruxist's tooth surfaces, jaw pain, headaches, damage to teeth or dental work, and over development of the jaw muscles. When bruxism is severe, it may be accurately diagnosed by the presence of jaw pain and over development of the jaw muscles. When bruxism is less severe, it may be difficult to diagnose. For example, wear facets are often detected by a dentist during a dental examination, but may have resulted from bruxing during a previous period of the patient's life. Because nocturnal bruxism is a subconscious activity, bruxists may not be aware of their bruxing and may not believe that they brux even when presented with strong circumstantial evidence.
The primary treatment for nocturnal bruxism is the use of intraoral occlusal splints or "mouth guards," which are generally semi-rigid plastic covers for the upper or lower teeth. Occlusal splints are generally fabricated for a specific individual from an impression taken of the individual's teeth. While the splints protect the teeth from wear due to bruxism, research indicates that they may exacerbate or reduce the bruxism itself depending on the particularities of the situation.
Occlusal splints are relatively expensive sometimes costing a bruxist more than $500. Occlusal splints also present numerous inconveniences to the user. They require frequent cleaning, are difficult to clean, require periodic replacement, inhibit speech, and are frequently lost. For couples sleeping together, occlusal splints are far from romantic. Some users perceive that occlusal splints accelerate tooth decay. As a result of these and other perceived disadvantages, without compelling evidence of current bruxism, dentists and patients are reluctant to procure an occlusal splint.
It is the object of this invention to provide an incontrovertible, inexpensive, and convenient means for measuring the severity of bruxism.
SUMMARY
The invention consists of a bruxism measurement device including a thin shell formed to fit closely over either the upper or lower teeth. The shell is thin enough that it does not interfere substantially with the normal occlusal action of the user's teeth. It is thin enough and fits tightly enough that the device is comfortable and does not interfere with normal speech, breathing, or tongue motion.
The shell consists of one or more layers of material. In a preferred embodiment, an outer layer, nearest the occlusal interface, wears away when substantial bruxing occurs, revealing an inner layer of material. This inner layer of material is optically distinguishable from the outer layer, so that the location and severity of the bruxism can be determined.
Because the jaw muscle opens in a combination of linear and angular motions, the shell may be tapered from the front of the mouth to the rear of the mouth so that the teeth meet in a normal bite pattern when the shell is worn.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying drawings, where:
FIG. 1 is an overall perspective view of an embodiment of the invention comprising multiple layers of material;
FIG. 2 is a perspective view of a portion of the shell in FIG. 1 showing a worn region revealing the inner layer of material;
FIG. 3 is a cross-sectional view of the shell in FIGS. 1 and 2 and of a corresponding tooth.
FIG. 4a is a diagram of the human jaw, tooth, and skull system in a closed position;
FIG. 4b is a diagram of the human jaw, tooth, and skull system in an open position;
FIG. 5 is a perspective view of an embodiment of the invention showing an alphanumeric identification code; and
FIG. 6 is a perspective view of an embodiment of the invention showing an alphanumeric code.
FIG. 7 is a top view of a disc of material, from which a shell may be formed, showing a grid pattern.
DETAILED DESCRIPTION
In use, at least one shell is formed to fit a particular patient. The patient may then wear a shell over a predetermined period. The shell may then be examined and the wear quantified.
In a preferred embodiment of the invention, the shell 10 in FIG. 1 is formed to fit the upper, or maxillary, teeth. The shell fits closely over the tooth 30 in FIG. 3, including a portion of the sides of the tooth. Because the sides of at least some teeth are narrower at the gum line than at their widest point, the shell "snaps" lightly over the teeth and is retained elastically.
The shell is preferably fabricated by forming a thin sheet of heated polymeric material over a pattern made from the patient's teeth. This forming may be accomplished by a pressure or vacuum forming machine such as the BioStar pressure forming machine manufactured by Schedu Dental.
The shell is made from a material that is easily deformed in order to snap over the teeth, but that is not so stiff that the forces exerted by the shell on the teeth cause discomfort. In a preferred embodiment the shell is formed from polyvinylchloride, with a thickness before forming of approximately 0.5 mm.
In a preferred embodiment, the shell consists of a plurality of layers, each layer distinguishable from the adjacent layers. In another preferred embodiment, each of the layers is a different color so that the regions of wear can be detected and measured optically.
The outermost layer of the shell, the one visible when the shell is engaged on the teeth, is preferably tooth colored, so that the shell is not easily noticed by observers.
In a multi-layered embodiment, when a particular region of the shell is worn away, an underlying layer is exposed. FIG. 2 shows an embodiment of the invention in which the outer layer 20 is worn away revealing an inner layer 21. When a two-layer shell is used, the extent of bruxism is indicated by the area of the worn regions. When using a shell consisting of three or more layers, the depth of wear may also be easily determined from the observed wear patterns and used to refine the measure.
In a preferred embodiment, the shell 10 in FIG. 3, is formed from two layers of polyvinylchloride. The outermost layer 20 is 0.075 mm thick and the innermost layer 21 is 0.425 mm thick. The outermost layer is ivory colored and the innermost layer is orange colored.
In another preferred embodiment the shell is formed from two layers. The innermost layer is 0.425 mm thick and is orange-colored polyvinylchloride. The outermost layer consists of a 0.075 mm thick layer of white ink or paint applied to the innermost layer. Other color and material combinations are possible.
In another preferred embodiment, the outer layer is non-wetting for a phosphorescent or fluorescent dye; and the inner layer is wetting for the dye. When the outer layer is worn through, an inner layer is exposed which can be wet by a dye. The regions of wear may then be distinguished optically by first dipping the shell in the dye, and then observing the fluorescence or phosphorescence in the image.
In another preferred embodiment, the outer layer is opaque to ultraviolet--UV--light, and the inner layer is made of a phosphorescent material. When exposed to UV light, the worn regions of the shell will be illuminated.
In another preferred embodiment, the shell is translucent. In this embodiment, regions of wear will transmit more light than regions of non-wear. Wear may therefore be observed by illuminating the shell from one side and observing differences in the amount of transmitted light from the other side.
The effect of a two-layer shell need not be accomplished with two distinct materials. In a preferred embodiment one "layer" may be the surface finish of the shell with the inner "layer" the underlying material. In a preferred embodiment, a shiny finish on the outer surface of the shell is worn away by the bruxing action, creating dull spots on the shell. These dull spots may be detected visually.
The optically distinguishable layers allow for electronic imaging and automated measurement of the worn regions of the shell. In a preferred embodiment, the layers of the shell are made of materials that are distinguishable by standard red-green-blue--i.e., RGB--digital imaging.
In a preferred embodiment, the outermost layer of the shell includes a dull finish to avoid reflections and the resulting bright spots in an optical image, which could be confused with worn regions of the shell when automatically analyzing a digital image.
The human jaw is a complex joint involving both linear and angular motions when opening and closing. In FIG. 4, jaw 41, skull 40, and jaw joint 41 are shown schematically. When the jaw opens, there is both vertical linear translation and angular rotation. Let L be the length from front to back of the set of occlusal surfaces of the teeth. Let A be the angle with respect to the upper teeth that the jaw assumes when open. This angle is called the Frankford Mandibular Angle. When the upper and lower teeth are in contact, the angle A is zero by definition. If the jaw opened only linearly, i.e., if A remained zero as the jaw opened, then the introduction of a shell of constant thickness between the upper and lower teeth would not disturb the normal occlusal pattern of the teeth. However, few individuals have jaws with this characteristic. Humans more frequently have a visually noticeable jaw angle, A, when the jaw is fully open. When the jaw is open to accommodate a shell thickness of approximately 0.50 mm, the value of A may be as much as 0.50 degrees. As a result, when a shell of constant thickness is introduced between the upper and lower teeth, the teeth closest to the jaw joint may make contact with the shell, while the teeth distal from the jaw joint do not make contact. In effect, the jaw is "wedged open" by the shell. In a preferred embodiment, the shell 10 in FIG. 5 is tapered from front to rear so that the thickness 50 is greater than the thickness 51. This taper allows for contact between the teeth and the shell along its entire length, and gives rise to a more natural occlusal pattern. The difference between thickness 50 and thickness 51 is approximately equal to L multiplied by the Sine of the angle A. For L equal to 50 mm, and A equal to 0.25 degrees, when the jaw is open to accommodate a shell of thickness 51, the difference between thicknesses 51 and 50 is approximately 0.22 mm. In a preferred embodiment, the taper is continuous from front to rear.
Although shells are preferably formed for each particular patient, shells for different patients look alike and are difficult to distinguish from one another. Without some identification means, the only way to positively verify a match between shell and patient is to test the fit. Testing the fit requires subsequent sterilization in the event of a mismatch and is perceived by the patient to be unprofessional. Furthermore, for an agent analyzing the wear of the shell, verifying the identity of a shell by testing the fit may not be possible because the patient may not be present. To avoid these problems, the invention includes a coded identification label on the shell. In a preferred embodiment, the shell 60 in FIG. 6 includes an alphanumeric identification code 61. This code uniquely identifies the patient, the prescribing dentist, and the ordinal rank of the shell among those formed for the patient.
In a preferred embodiment, the tapered thickness of the shell is obtained by forming the shell from a flat disc that is also initially tapered. Because a thermal forming process gives rise to deformation and stretching of the material, the thickness of the shell may differ from the initial thickness of the disc from which the shell is formed. In a preferred embodiment, a grid pattern is included on one side of the disc 70 in FIG. 7. This pattern gives a visual indication of the amount of stretching that occurs during forming. If the grid remains geometrically regular after forming, the thickness of the shell is tapered proportionally to the taper of the original disc. If, in contrast, the grid is irregular, then the taper of the shell may be disproportionate to that of the original disc of material. This information may be used in at least two ways. First, if the deformation is very irregular, the shell may be rejected and another formed. Second, an estimate of the amount of stretching revealed by the grid may be used to correct the estimate of the severity of the wear. For example, an indication of wear in a more highly stretched, and therefore thinner, region of the shell is less severe than wear in a thicker region of the shell.
The human mouth contains many types of bacteria, some of which are harmful. In a preferred embodiment, the shell includes a disinfectant coating to inhibit the growth of harmful bacteria.
Over a prolonged period of use, the shell may develop an unpleasant taste and odor. In a preferred embodiment, the shell includes a mint flavor and scent. Other flavors and scents, such as cinnamon or citrus, are possible.
The foregoing discussion should be understood as illustrative and should not be considered to be limiting in any sense. While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing form the spirit and scope of the invention as defined by the claims.
|
A bruxism monitoring device comprising a thin shell formed to the shape of and elastically retained to one or more teeth, said shell further comprising: a plurality of layers having mutually distinguishable colors, each color distinguishable from the colors of adjacent layers; and a material thickness that is greater anteriorly than posteriorly. The outer layer of the shell, when worn away by grinding action, reveals an inner layer. The regions of wear may be analyzed to determine the extent of the bruxing activity.
| 0
|
This is a division of application Ser. No. 07/378,437, filed on July 10, 1989 now U.S. Pat. No. 4,979,956.
BACKGROUND OF THE INVENTION
The present invention relates to a device for repairing severed or lacerated tendons and ligaments and, more particularly, the invention relates to a device having a flat band body constructed of resilient synthetic textile fiber and capable of receiving a suture element secured thereto at opposite ends of the body. Also contemplated by the invention are methods of anastomosing ends of severed or lacerated tendons and ligaments along an interface of approximated ends, by placing a device intratendonously, in the case of a tendon, or in juxtaposition, in the case of a ligament, bridging or spanning approximated ends, and suturing together either the tendon and the device or the ligament and the device. The objective is to provide a device and method for restoring tendons and ligaments, as nearly as possible, to their pre-damaged condition.
The successful repair of tendons, particularly hand flexor tendons, has been a problem for surgeons for many years. The past and current approach most commonly used by surgeons to achieve tendon repair is to anastomose severed tendons by using one of a variety of suturing techniques. A number of such techniques are commonly known and referred to as Bunnell, Kessler, Klienert, Tsuge and Becker, to name but a few. These techniques, while useful, are not entirely satisfactory because they allow surgeons to achieve successful repairs in only about 70% of the patients treated. Therefore, in view of the history of suture techniques which have been proposed and implemented from time to time by surgeons without any real improvement in repair strength or surgical result, the need for an improved device and method of anastomosis were clearly evident.
In addition to the foregoing suturing techniques most often used in tendon repair, in an effort to overcome the deficiencies encountered in the straight suturing approach, other devices and approaches have recently been tried to effect tendon repair. A typical device encountered might be one like that disclosed in U.S. Pat. No. 4,469,101. The teaching embodied in this patent specifies a structure having an open network or mesh of helically formed members to define a hollow tubular device wherein opposing ends of a lacerated tendon are introduced and brought into contact within the tube. The opposite ends of the tube are then sutured to the outer tendon wall and the contacting tendon ends are allowed to heal. Another device typically encountered in tendon repair might be one like that disclosed in U.S. Pat. No. 4,501,029. This patent provides a continuous solid wall tubular device having in communication therewith a number of transversely extending passages. The tube is inserted between a replacement tendon and the tendon sheath. After blood supply from the sheath to the replacement tendon is established through the tubular passages, free movement of the tendon is established within the sheath. A third device encountered might be the plastic prosthetic tendon disclosed in U.S. Pat. No. 3,176,316. This patent provides a prosthesis having a solid central segment and hollow tubular ends comprising a mesh network wherein ends of a tendon are introduced and the prosthesis is sutured to the tendon.
There are certain disadvantages associated with each of the aforementioned tendon repair techniques and devices which the present inventive device and method either overcome or substantially lessen. Specifically, through the use of suturing techniques alone, irritations are minimized since sutures are buried inside the endotendon, but the strength of the anastomosis is not strong enough to allow aggressive mobility during healing. Consequently, there often occurs dehiscence of the suture leading to separation of approximated tendon ends, tissue ingrowth and slow or incomplete tendon healing. Inherent in the tubular mesh devices which are sutured to the tendon at ends of the devices is the exposure of a large amount of synthetic material on the outside of the epitenon which can cause excessive irritations. These irritations frequenty lead to adhesions between the injured tendon and the tendon surrounding which leads to retarded healing. The inventive device offers a minimum of irritation since it is substantially buried inside the endotendon, yet it offers higher strength of the anastomosed tendon compared to repairs using sutures. Lastly, the present device is one of structural simplicity which avoids both the complex geometry presented in the solid wall tubular device having a series of selectively positioned blood conveying passageways and the need to precisely locate such a prosthesis in the body to assure an adequate blood supply to the replacement tendon.
It should be understood that, while much of the foregoing discussion is directed toward tendon repair, the teachings encountered are also generally applicable to the repair of damaged ligaments. Clearly, there exists a need for a repair device which fosters superior mechanical repair properties and better healing characteristics than is currently found in the relevant surgical field. The present inventive device and method satisfies the need and, hence, advances the art field of tendon and ligament repair.
SUMMARY OF THE INVENTION
The present invention relates to a device used for repairing severed connective tissue of tendons and ligaments by approximating ends of the severed tissue and comprises an elongated body portion having a flat band structure with the body portion at opposite ends adapted to be connected to at least one needle bearing suture. The body structure may be a non-woven fabric, a composite reinforced with chopped fiber, a polymer sheet or a fabric which can be selected from a class of warp knits, weaves, nets and braids. The preferred braided fabric would be a triaxial braid or a flat band triaxial tube having either a monocomponent or bicomponent fiber element selected from a polymeric grouping and may include an elastomeric component. The preferred polymer for a monocomponent device body would be polyethylene terepthalate while for a bicomponent device the preferred polymers for the device body would be polyethylene terepthalate and polyester/polyether block copolymer. A suture or sutures may be lock stitched to opposite ends of the device body and may be incorporated into the body structure axially in either a longitudinal direction or in a bias direction. Additionaly, a suture or sutures may be sewn into the body. The device body and associated suture or sutures may be covered with one or more gel coatings selected from a class of hydrogels with a preferred coating being crosslinked calcium alginate. The body portion may assume a number of shapes but either a rectangle or a polygon, having ends tapered substantially to a point, is preferred. The ends of the body portion are preferably sealed to maintain edge integrity.
Also contemplated within the scope of the present invention are methods for repairing severed connective tissue of tendons and ligaments utilizing the inventive device heretofore described. Specifically, one method comprises the steps of creating a slot in the tissue of each opposing end of a severed tendon, where severance occured, inserting a first end of the device into one of the incised slots, inserting a second end of the device into the other of the incised slots, approximating opposing ends of the severed tissue, enclosing the device and therewithin bridging the ends, and suturing the tendon and the device together, passing sutures through the tendon and the implanted device along at least a portion of the length of the device, to anastomose the tendon along approximated ends of the severed connective tissue. A second method, relating to the repair of severed connective tissue of a ligament, comprises the steps of providing at least one inventive device, approximating opposing ends of the severed tissue, juxtaposing the ligament and the device with the device spanning approximated ends, and suturing the ligament and the device together, passing sutures through the ligament and the juxtaposed device along at least a portion of the length of the device, to anastomose the ligament along approximated ends of the severed connective tissue. In each of the methods, suturing will span at least the approximated ends and, preferably, suturing will be performed along substantially the entire length of the device.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific results obtained by its use, reference should be made to the corresponding drawings and descriptive matter in which there is illustrated and described typical embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged schematic representation of a tendon and ligament repair device, in accordance with the principles of the present invention, illustrating a flat band triaxial braid fabric structure having a single bias suture incorporated into the fabric body with the suture lock stitched to the body at opposite ends of the body.
FIG. 2 schematically illustrates a severed tendon, drawn at reduced scale, with slots incised in the tendon ends, before implantation of the repair device.
FIG. 3 is similar to FIG. 2, but with tendon ends approximated, and schematically illustrates the tendon repair device of FIG. 1 located within the endotendon prior to suturing.
FIG. 4 is similar to FIG. 3 and illustrates a completed repair showing suture penetration of both tendon and fabric body uniting tendon and device.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 4.
FIG. 6 is an enlarged schematic alternate embodiment of the invention showing in phantom a ligament with approximated ends and a flat band triaxial braid fabric structure, in place but prior to suturing, with a single axial suture incorporated into the fabric body with the suture lock stitched to the body at opposite ends thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The description herein presented refers to the accompanying drawings in which like reference numerals refer to like parts throughout the several views, and in which, referring to FIG. 1, there is illustrated a repair device 10 of the present invention. The device has an elongated body portion 12 of flat band structural configuration, preferably a triaxial braid with the braid schematically designated as 11, and at a first end 14 and at a second end 16 a suture 18, having needles 20 and 22 at opposite ends, is connected or anchored to the body ends by a locking stitches 24 and 26. It should be understood that many types of knots or locking stitches, such as a double throw suture locking stitch, would be suitable to anchor the suture to the body portion. Locking the suture to the body could be accomplished at any time, as desired. The device shown in FIG. 1, it should be remembered, is a schematic representation and, therein depicted, the device has a flat band triaxial braid fabric structure with a single bias suture braided into the fabric body. It should also be understood that more than one suture could be attached to or incorporated into the fabric body and locked to the body ends. Furthermore, a suture or sutures could be sewn or stitched to the body along the body length instead of being braided into the body. In the preferred form of the device, the lock stitching of the suture to the ends of the braid body prevents the braid structure from bunching during insertion into tissue. The stitching also serves to center the suture pull of the device, thereby easing the insertion of the device into connective tissue. Also contemplated within the scope of the invention is a suture or sutures not incorporated into the fabric body per se but merely locked to one or both of the body ends. The ends 14 and 16 may be sealed along edges 28 and 30 to maintain edge integrity. Edge sealing may be accomplished using an ultrasonic sealing process or other means of heat treatment to keep edges from unraveling or separating.
The device body portion may be structurally configured as a non-woven fabric, a polymer reinforced with chopped fiber, a polymer sheet, a warp knit, a weave, a net or a braid. The construction of the desired flat band fabric into any one of these body portion structural configurations would be within the skill of those who manufacture textile products. A preferred structure would be a braid, preferably a triaxial braid. A flat band or flattened triaxial tube is within the scope of the invention. A triaxially-braided fabric, such as the ones schematically depicted in FIG. 1 and FIG. 6, and the methods of manufacturing them in different configurations, namely, flat bands, flat tubes, tubes, patches and strips, to name but a few, are well known to those skilled in the art of manufacturing braided polymeric articles. The triaxial braid may consist of a monocomponent fiber selected from a group of polymers consisting of polyethylene terepthalate, polyethylene, polypropylene, polyaramid, polyamide, polyetheretherketone, polyester/polyether block copolymer, liquid crystal polymeric fiber, nylon and carbon. The preferred polymer would be polyethylene terepthalate. The triaxial braid may also have a bicomponent fiber makeup with its components selected from the same polymer grouping. One of the components of the bicomponent braid should be elastomeric with the preferred elastomer being polyester/polyether block copolymer. The preferred bicomponent braid comprises a first component of polyethylene terepthalate and a second component of polyester/polyether block copolymer.
The device may be coated to improve the ease of surgical installation and to minimize irritation to tissue during healing. The suture or sutures could also be coated to minimize adhesions formed during healing. The coating could be a gel, specifically a hydrogel, selected from the group consisting of sodium alginate, hyaluronic acid, crosslinked hyaluronic acid, crosslinked calcium alginate and a calcium alginate crosslinked hyaluronic acid mixture. The preferred lubricious coating for the device and sutures is crosslinked calcium alginate.
The device body as shown in FIG. 1 defines a polygon having opposed longitudinal ends each tapering to a point with the points, preferably, lying along the central longitudinal axis. The body may, however, as is shown in FIG. 6, take a rectangular shape. Other flat band structural shapes would be suitable and are within the scope of the present invention.
Turning to FIG. 2 through FIG. 5, in FIG. 2 there is shown severed connective tissue of a tendon 32 having separated ends 34 and 36. In each end 34 and 36, slots 38 and 40 have been incised within the endotendon using a suitable blade or cutting device (not shown). Each slot 38 and 40 will preferably be configured to conform substantially to one half the size of the repair device 10. FIG. 3 shows device 10 located within slots 38 and 40, suture 18 at opposite ends 14 and 16 of device 10 passing through tendon 32, and separated tissue ends 34 and 36 approximated as shown at 42. Device 10 is closed within the approximated tissue, bridging ends 34 and 36 which are in contact along joint 42. FIG. 4 and FIG. 5 depict a completed repair wherein the tendon and the device have been sutured together and the suture ends tied at 44. Suturing of the device into the tendon can be accomplished in many different ways. Thus, the device does not restrict the personal suturing preference of different surgeons. Anastomosis of the tendon will occur along approximated ends at 42. Suturing should span at least the approximated ends and, preferably suturing should be performed along substantially the entire length of the implanted device 10.
Turning to FIG. 6, there is schematically shown an alternate embodiment of the invention. Here depicted is a rectangular flat band repair device 46 having a triaxially braided fabric structure 11' and a suture 18', bearing needles 20' and 22', incorporated into elongated body portion 48 and axially oriented in a longitudinal direction. At first and second ends 50 and 52, suture 18' is affixed to the body ends by locking stitches 24' and 26'. As aforementioned in respect to the device 10, many types of knots or locking stitches would be suitable to affix the suture to the body portion and stitching could be accomplished when desired, namely, at time of manufacture or by a surgeon prior to device use. Lock stitching would be particularly useful, in addition to ease in installation, that is, prevention of fabric bunching, to keep the suture from being pulled through the fabric. More than one suture could be used and attached to or incorporated into the body fabric. Additionally, a suture might be sewn to the body along the length of the body rather than being braided into the body. The ends 50 and 52 may be sealed along edges 54 and 56 to maintain edge integrity, as in the case of device 10. All of the other structural features associated with device 10 are equally suitable for device 46.
In FIG. 6, device 46 is shown to be particularly useful in the repair of severed connective tissue of a ligament, illustrated in phantom and designated as 58. It should be understood, however, that a device of rectangular configuration would be equally useful in tendon repair and slots 38 and 40, as shown in FIG. 2, could assume a rectangular shape. Likewise, device 10 would be equally suitable in the repair of a ligament. Device 46, as provided in FIG. 6, is shown positioned alongside ligament 58 having severed ends approximated at 60. The device spans the approximated ends. It should be understood that more than one device could be used for the repair. While a completed repair is not shown in FIG. 6, a suturing technique like that shown in FIG. 4, and other techniques described in respect thereto, could be used to suture together ligament 58 and device 46. Anastomosis of the ligament will occur along approximated tissue ends at 60. Suturing should span at least the approximated ends and, preferably, suturing should be performed along substantially the entire length of device 46. In each of the repair techniques, namely, tendon and ligament, devices 10 and 46 are biocompatible and can be made from permanent, non-body absorbable materials, or from resorbable materials.
As heretofore mentioned, braiding can be accomplished using known technology and the inventive device can be manufactured using existing braiding machines modified to incorporate longitudinal fibers into the braided structures. By way of example, and not to be construed as limiting the invention, a 0.07 inch wide monocomponent polyethylene terepthalate device 10 can be braided on a 32-carrier triaxial braider using 70 denier white polyethylene terepthalate type 52 multifilament yarns and a single green 4-0 polyethylene terepthalate suture. The finished product is composed of 31 polyethylene terepthalate yarns and one 4-0 polyethylene terepthalate suture on the bias and 16 polyethylene terepthalate yarns on the longitudinal axis. In another example, a 0.07 inch wide bicomponent device 10 can be braided on a 24-carrier triaxial braider using 220 denier polyester/polyether block copolymer monofilaments, 70 denier white polyethylene terepthalate type 52 multifilament yarns, and a single green 4-0 polyethylene terepthalate suture. The finished construction is composed of 23 polyethylene terepthalate yarns and one 4-0 polyethylene terepthalate suture on the bias, and 12 polyester/polyether block copolymer fibers on the longitudinal axis. It should be understood that wider or narrower devices could be manufactured. The device is made from safe materials that surgeons are comfortable implanting and the device can easily be made in a variety of sizes to address different soft tissue repair situations. Device needles could be swaged onto the suture ends of affixed by other suitable means. Laboratory testing of a repair device used to anastomose explanted canine and bovine tendon has demonstrated that the initial strength of the repair junction is approximately twice the strength of tendon repairs made using conventional suturing techniques.
While in accordance with provisions of the statutes there is described herein specific embodiments of the invention, those skilled in the art will understand that changes may be made in the form of the invention covered by the claims appended hereto without departing from the scope and spirit thereof, and that certain features of the invention may sometimes be used to an advantage without corresponding use of the other features.
|
A device, suitable for use in repairing a lacerated or severed tendon, particularly a hand flexor tendon, having a flat band body with opposite ends of the body designed to anchor connecting sutures. The device also finds applicability in the repair of lacerated or severed ligaments. Also disclosed is a method of repairing a severed tendon by implanting a flat band device suturing together the device and the tendon to effect an anastomosis along approximated ends of the severed tendon. Further disclosed is a method of repairing a lacerated or severed ligament.
| 3
|
This is a continuation of application Ser. No. 635,012, filed Nov. 25, 1975, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to the pyrolytic deposition of silicon nitride onto a heated substrate and to substrates having uniform films of silicon nitride deposited thereon. More particularly, this invention relates to the deposition of silicon nitride by reacting a halosilane with ammonia in an evacuated system.
Silicon nitride (Si 3 N 4 ) is a dense, chemically inert, dielectric material of extreme hardness, low thermal conductivity and high resistance to molecular diffusion. These properties have made silicon nitride an attractive and valuable material for a wide range of applications. For example, it is useful in the fabrication of semiconductor devices as oxidation masks, capacitor dielectrics for bit storage, masking layers, polish retarders, etc.
Various methods for depositing silicon nitride are known, but while the processes described in the prior art are functional in certain applications, they present drawbacks in other areas. For example, it has been found to be extremely difficult to deposit silicon nitride onto semiconductor substrates in a manner that will allow a good growth rate, uniform deposition, and a high quality coating in an economical process.
Thus, the deposition of silicon nitride by the reaction of either silane or dichlorosilane with ammonia at a pressure of about 1 atmosphere is conventional. However, the aforementioned processes are not completely satisfactory for depositing silicon nitride on semiconductor substrates because of the high cost of the equipment, over-all processing costs including the necessity of employing a carrier gas, and low throughput. Furthermore, these processes result in poor thickness uniformity on individual wafers and from wafer-to-wafer.
Accordingly, E. Tanikawa et al in "Chemical Vapor Deposition In An Evacuated System", C.V.D. 4th International Conference, ECS, G. F. Wakefield and J. M. Blocher, ed., 261-273 (1973) describe the reaction of silane and ammonia in an evacuated system to deposit silicon nitride on silicon wafers. However, wafers treated according to this process have been found to have a thicker ring of silicon nitride around the edge of the wafer together with silicon or silicon nitride dust and boat marks on the wafers. Furthermore, for best results, wafer size and spacing in the furnace must be uniform in carrying out the deposition.
It has now been found in accordance with this invention that silicon nitride can be deposited to provide surprisingly unexpected results by employing a halosilane as a reactant and carrying out the process in a vacuum.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved method for the pyrolytic deposition of silicon nitride.
It is a further object of this invention to provide an economical process for the deposition of silicon nitride characterized by high through-put.
It is another object of this invention to provide uniform and continuous coatings of silicon nitride which are free from defects.
It is still another object of this invention to provide improved yields of semiconductor devices made from silicon wafers having silicon nitride deposited thereon.
In accordance with this invention, silicon nitride is pyrolytically deposited upon a substrate by contacting a mixture of a halosilane and ammonia with a substrate in a vacuum at an elevated temperature.
The process of this invention will be better understood by reference to the following description of the invention and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an apparatus for use in the process of this invention.
FIG. 2 is an isometric view, partly broken away, of a furnace tube loaded with wafers and suitable for use in the practice of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the Figures, there is shown a furnace tube 10 heated by resistance heat coils 12 adjusted to give the desired temperature as described in detail below.
A gas panel generally referred to as 14 leads to the inlet end of furnace tube 10. This gas panel contains a source of halosilane 16, nitrogen 18 and ammonia 20, which are admitted to the furnace tube by opening valves 22, 24, 26 and 28. The halosilane is any monohalogenated or polyhalogenated silane, including the chlorosilanes, fluorosilanes, bromosilanes and iodosilanes. Preferably chlorosilanes such as chlorosilane, dichlorosilane, trichlorosilane and silicon tetrachloride are employed. The flow of gases is controlled by flow meter valves 30, 32 and 34. An end cap 36 is in engagement with furnace tube 10 to provide a vacuum seal within the tube, and the pressure is read by vacuum gauge 38. Exhaust 40 serves to vent by-products and unreacted starting materials from the tube. As shown, the furnace tube holds a quartz boat 42 loaded with a plurality of silicon wafers 44, which are positioned with their broad surfaces perpendicular to the cylindrical axis of the tube. The wafer positioning is clearer in FIG. 2. Preferably, a spacing of 50 to 500 mils between wafer surfaces is employed, with as many wafers as can be accommodated by the tube being processed at one time. While the type of wafer positioning shown in the drawings provides for maximum utilization of the tube, other means of positioning the wafers are contemplated. Furthermore, the process can be carried out in different types of vacuum apparatus.
In carrying out the process of this invention, the furnace tube is heated to the appropriate temperature for the particular halosilane and purged with nitrogen. Then the boat containing silicon wafers is loaded into the tube. The selected temperature should be high enough to give an acceptable growth rate while minimizing the competitive thermal decomposition of the halosilane to produce silicon. Generally a temperature between about 650° C. and 1000° C. is employed.
Another feature of this invention is that a temperature ramp can be established within the furnace tube. Thus, there can be a temperature variation along the tube, up to 100° C., and preferably from 10° C. to 50° C., with the lowest temperature being near the gas inlet end of the tube and the highest temperature near the opposite end of the tube. It has been found that utilizing a temperature ramp allows more flexibility in optimizing down-the-boat uniformity and deposition rate. Higher temperatures increase both the deposition rate and the source gas depletion. Source gas depletion decreases wafer uniformity down the boat. Since higher deposition rates are desirable to increase throughput, one compensates for source gas depletion by temperature ramping, with the more depleted end at the highest temperature.
After the boat has been loaded into the tube and the desired temperature achieved, a vacuum less than 50μ is established. Then, ammonia and halosilane are admitted to the tube, bringing the pressure to from about 300 millitor to about 10 torr. The flow is regulated so that the mole ratio of ammonia to halosilane is from about 1 to 500:1. Furthermore, the ammonia is metered into the furnace tube at a rate between about 0.01 and 10 cc/sec, while the halosilane is metered into the tube at a rate between about 0.01 and about 0.5 cc/sec. It has been found that the growth of silicon nitride under these conditions is about 5 to 100 A°/minute; the process is continued until the desired thickness is deposited on the wafers. For most semiconductor applications, 200-2000 A° thick layers are desired, but the process of the invention is suitable to deposit layers of any thickness.
The silicon nitride layers produced according to this process have been found to have many advantages over those produced by prior art processes. Thus, the peripheral ring of thicker nitride found on wafers treated with silane and ammonia under vacuum is eliminated. Furthermore, silicon or silicon nitride dust formation and boats marks found in the aforementioned silane process were reduced to an insignificant level. Since the silicon nitride layers are uniform, more devices can be made from semiconductor wafers treated in accordance with this invention, further enhancing the attractiveness of the process.
The following example will serve to illustrate the practice of this invention.
EXAMPLE 1
One hundred fifteen precleaned 3-inch diameter silicon wafers were loaded into a three-rail quartz boat 16 inches long with 3/32 inch wafer spacing; in accordance with standard diffusion techniques, five dummy wafers were placed at each end of the boat. Then the boat was placed in a 101 mm outside diameter quartz tube in a thermco furnace. The temperature profile of the furnace was ramped so that thermocouple measurements at three equidistant points covering the center 20 inches of the furnace gave readings of 730° C., 750° C. and 770° C. respectively, with the lowest temperature at the end adjacent to the gas inlet. The furnace was evacuated to less than 50μ and purged with nitrogen for ten minutes at a pressure of 2 torr. Then the nitrogen was turned off and the system pumped down to a pressure less than 50μ. Ammonia was injected at a flow rate of 0.24 cc/sec for one minute. Then dichlorosilane was injected at a flow rate of 0.02 cc/sec while continuing the injection of ammonia. After 60 minutes, the dichlorosilane flow was terminated and the ammonia flow was terminated one minute later. These flow rates correspond to a molar ratio of ammonia to dichlorosilane of about 12 to 1. Then the furnace was pumped to a pressure of less than 50μ and purged with nitrogen for five minutes at a pressure of 2 torr. The vacuum valve was closed and the system back-filled with nitrogen. The boat was unloaded and the wafers evaluated. They were found to have a 1000A° thick layer of silicon nitride which was uniform from wafer to wafer ±10%, and around the wafer ±1%; the wafers exhibited no haziness and no boat marks.
|
Silicon nitride is pyrolytically deposited by the reaction of a halosilane with ammonia in an evacuated system. The process is particularly useful in providing uniform layers of silicon nitride on silicon wafers to be used in the fabrication of semiconductor devices.
| 2
|
BACKGROUND OF THE INVENTION
This invention relates to tank valves for tank-type toilets and more particularly to a tank valve adapted to regulate and minimize the amount of water utilized in flushing.
Conservation of water has become recognized as of late to be of considerable importance, especially in urban areas. While perhaps this concern was precipitated in recent years by extended periods of drought, the concern with water conservation is now recognized as an ever-present one in conjunction with a general spirit of conservation of all natural resources.
A major source of over-consumption of water is the tank-type toilet which is used almost universally. The tank of a tank-type toilet provides a reservoir of water typically 5 to 8 gallons. Such toilets contain a tank valve which sits upon a valve seat disposed in the exit port at the bottom of the tank. When the toilet lever is manually actuated, the tank valve is lifted off the valve seat permitting the water in the tank to drain through the exit port to the toilet. The tank valve is designed to contain an air pocket and therefore remains open during flushing/draining due to the buoyancy resulting from the air pocket. Thus the valve resists closure despite the downward movement of the water level in the tank. It is not until the water level drops to a level adjacent the valve seat that the tank valve, now without water to buoy it, drops back in place over the valve seat, thereby closing the exit port. A float attachment in the tank being downwardly displaced as the water level recedes with flushing, actuates a water inlet valve which fills the tank with water. Return of the float to a predetermined position, caused by the rising water level in the tank, closes the inlet water valve.
It is known, however, that satisfactory toilet operation does not in most cases, especially where simply liquid waste is involved, require flushing with the full complement of water contained in the toilet tank. Hence, water conservation can be practiced by regulating the amount of water used in flushing. Of course, when solid waste is involved, it is desirable to then employ the full tank of water during flushing.
To this end, there have been a number of prior art devices attempting to achieve regulating flushing. Thus, for example, U.S. Pat. No. 3,733,618 to Weigand, issued May 22, 1973 utilizes a check valve on the flush valve for bleeding air therefrom and thereby hasten its closure of the valve seat. Similarly, U.S. Pat. No. 3,858,250 to Coglitore, issued Jan. 7, 1975, describes a plastic tube for bleeding air from the tank valve to a point above the water level in the tank; U.S. Pat. No. 2,883,675 to Hartman, issued Apr. 28, 1959, describing a flush tank valve whose byoyancy can be regulated; and U.S. Pat. No. 2,940,084 to Fabbi, et al., is issued June 14, 1960, describing a double flush valve assembly.
Examples of tank valves may be found in U.S. Pat. No. 2,015,614 to Burnes, issued Sept. 24, 1935; U.S. Pat. No. 3,086,218 to Gross, issued Apr. 23, 1963; and U.S. Pat. No. 3,187,348 to Gresham, issued June 8, 1965. In the patent to Gross there is disclosed a ball-type tank valve having a 1/8-inch hole in the stem thereof to provide stability to the valve to insure proper seating of the valve in the valve seat after complete flushing. In the Burnes Patent, a bulb-type valve is described having an air escape port therein to permit the valve to be weighted with water by the time the tank water has almost run out so as to obtain proper seating of the valve.
The prior art methods and devices for operating tank-type toilet to regulate the amount of water used in flushing suffer from the disadvantage of being relatively complicated and/or requiring substantial alteration of the tank valve assembly or the linkage used in manual actuation thereof.
SUMMARY OF THE INVENTION
It is accordingly the primary object of this invention to provide a tank valve which selectively permits flushing without the need for using the entire complement of water contained in the toilet tank.
A further object is to provide such a tank valve of simple construction and easily adapted to conventional tank-type toilets.
A still further object is to provide such a tank valve wherein the bouyancy of the valve is easily controlled to permit flushing with less than all of the tank water.
In accordance with this invention, a tank valve for use in a conventional tank-type toilet having an exit port at the bottom thereof and a valve seat with an opening therein for connecting the interior of the tank to the exit port is comprised of a closed upper portion and a lower portion having a cavity therein. The closed upper portion is adapted to extend across the valve seat with a predetermined appropriate surface area adapted to face the valve seat and close the opening in the valve seat when engaged therewith. The lower portion extends downwardly from adjacent the predetermined surface area and is adapted to extend within the opening of the valve seat. The lower portion has a downwardly facing opening at the bottom thereof in communication with the cavity and the cavity is of a size such that when substantially filled with air it provides a buoyancy force to the valve, when opened with respect to the valve seat, sufficient to delay the descent of the valve for a period during which water can be substantially emptied from the tank.
The lower portion has a vent hole in its surface extending into the cavity which is adapted to vent air outwardly from the cavity. The hole is located at a predetermined distance above the downwardly facing opening in the lower portion such that, as air is vented from the cavity, sufficient water enters the cavity to reduce the buoyancy of the valve and permit it to descend and close the opening in the valve seat before the tank has emptied, e.g., while the valve is still surrounded by water.
Once this position of the vent hole in the cavity is established, of course, the position of the hole can be made anywhere further away or above the opening in the bottom of the lower portion. A preferred position is one substantially the furthest distance above the opening. Where the upper portion contains a flange around the perimeter thereof, the vent hole can be placed at the interconnection of the flange with the lower portion.
The vent hole can be made at an angle with respect to the bottom portion if desired. In one embodiment of this invention the hole is made at an angle such that when the valve is opened with respect to the valve seat the vent hole is in a horizontal direction relative to the water level in the tank. The use of an angular hole is designed to afford the least impeded route for air expelled from the valve cavity.
The rate at which air is expelled from the cavity determines the duration of the time that the valve is open and, therefore, the amount of water allowed to drain before re-closure. The rate of expelling air is determined by the size of the vent hole provided in the lower portion of the valve. This size, of course, may be widely varied according to any desired predetermined amount of water required for flushing.
The tank valve is manually actuated and removable from the valve seat by a chain and lever connected thereto which lever is usually connected to a handle external of the tank. The valve may be further connected to a pipe in the toilet tank, typically the overflow pipe, by suitable hinges which allow for movement of the valve away from and toward the valve seat. Such valves are well-known in the art as "flapper valves."
Where it it desired to completely drain the tank water during flushing, e.g, for solid disposal, it is merely necessary to maintain and hold the external handle in whatever position causes the tank valve to assume a position above the valve seat until the draining is complete. The manual force thus serves to counteract the normal urge, as a result of venting, for the tank valve to close.
This self-venting of the tank valve can be seen to permit closure of the exit port prior to complete draining of the toilet tank; in contrast, the standard tank valve, due to its buoyancy resulting from the unreleased air pocket within the cavity, with not close until the water lever in the tank recedes to the valve seat.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view of a toilet tank having the vented tank valve of the invention mounted therein;
FIG. 2 is a fragmentary perspective partly in section of a flapper-type tank valve having hole vent means therein;
FIG. 3 is a vertical section view of a full toilet tank with the tank valve in a closed position;
FIG. 4 is a vertical section view showing a toilet tank, containing the tank valve of the invention, during flushing;
FIG. 5 is a fragmentary perspective view of an adapter means for converting conventional toilets for use with a vented tank valve of the invention; and
FIG. 6 is a vertical section view of another embodiment of the tank valve of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, a typical conventional toilet tank 10 is shown. The tank has a rear wall 11, a front wall 12, side walls 13, a removable top 14 and bottom wall 15. Located within the tank is a water supply 16 and a water supply valve 17 controlled by float 18 in a known manner. Tube 19 extends down into or slightly above overflow pipe 20.
Delivery pipe 21 is connected to the toilet bowl (not shown) and is connected by a suitable coupling 22 and washer 23 to the valve seat 24 which is in the outlet opening 25 in the bottom wall 15 of tank 10.
Tank valve 26 is of the flapper-type and is connected to overflow pipe 20 at hinges 27 by any known means. The tank valve comprises an upper portion 28, and lower portion 29 which is hollow and has a downwardly directed opening 30 at the base thereof. Upper portion 28 has a flange 28a around the perimeter thereof and appropriate levers 31 to engage hinges 27 and thereby allow pivotal movement of tank valve 26 around the hinges. Upper portion 28 has means 32 thereon to connect with chain 33. Chain 33 is connected to lever arm 34 which is actuated by flush handle 35 on the front wall 12 of tank 10.
In operation, flush handle 35 is raised or depressed (depending upon the particular linkage system utilized) to raise lever 34 so as to raise tank valve 26 to a position above valve seat 24 and thereby open exit port 36. Water 80 exits tank 10 through exit port 36 and through delivery pipe 21. In conventional flapper tank valve operation, the air contained in the cavity of the valve causes the valve to be buoyed in surrounding water 80 as the water flows out of the tank. As a result, the conventional valve remains open until the water recedes to a level near the valve seat at which point the valve is no longer supported by its buoyancy and descends and seats on the valve seat and closes the exit port.
As the water level drops in tank 10, float 18 descends and opens water inlet valve 17, and after tank valve 26 closes the exit port, water refills the tank from delivery pipe 16 until float 18 returns to a pre-determined position.
Referring to FIG. 2, there is shown tank valve 26 of the invention. As shown, the tank valve is of the flapper-type and has an upper portion 28 adapted to cover and close the valve seat with a predetermined surface area. Adjacent to this surface is lower portion 29 adapted to extend within the valve seat. Upper portion 28 is shown with a flange 28a around the perimeter thereof.
Tank valve 26 has appropriate lever arms 31 adapted to engage hinges 27 and thereby allow pivotal movement of the tank valve 26 about the hinges. Hinges 27 are shown here as attached by appropriate means to overflow pipe 20.
Lower portion 29 is hollow and therefore contains cavity 37 therein. Opening 30 defines the entrance to the hollow portion or cavity 37 and is located at the base of the lower portion 29. Lower portion 29 contains a vent hole 38 in the surface extending through the wall of the valve into cavity 37. The size and position of vent hole 38 is discussed hereinafter.
FIGS. 3 and 4 illustrate the operation and utility of the present invention. FIG. 3 shows conventional tank 10 with a full complement of water 80 wherein. Tank valve 26 is shown containing vent hole 38 in lower portion 29. Thus, prior to flushing, lower portion 29 sits within seat valve seat 24 and within exit port 36. Upper portion 28 rests over valve seat 24 to close it and prevent water from exiting through port 36.
As shown in FIG. 4, manual actuation of the flush handle causes lever 34 to rise. Chain 33 attached thereto and attaching means 32 located on tank valve 26 causes the valve to rise to a pre-determined position above valve seat 24 as shown by the dotted-line valve A. Water 80 begins to drain through exit port 36. With a conventional toilet, the tank valve contains air trapped in the cavity of the valve which keeps the valve buoyant until all the water drains from the tank. The present invention enables air 40 to be vented in a controlled manner from cavity 37 through vent hole 38 to reduce the buoyant forces progressively. In this manner tank valve 26 is caused to drop as shown by the solid-valve B and engage and close valve seat 24 even while tank valve 26 remains in surrounding water. This final seated position is shown by valve C. Thus, flushing is achieved without being required to utilize all the water contained in the tank 10.
The position of vent hole 38 relative to the opening 30 in the bottom of lower portion 29 is determined according to the following criteria. The vent hole 38 is placed in a position such that a sufficient amount of air contained in cavity 37 is expelled or vented therefrom to reduce the buoyancy of the valve to an extent which enables tank valve 26 to drop and engage valve seat 24 while still in surrounding water which would otherwise buoy the tank valve, i.e., before the tank empties. Thus, the position of vent hole 38 in the surface of lower portion 29 is determined by the extent of flooding of the cavity of the valve that is required to cause the valve to close prematurely.
Once a position of vent hole 38 is established which causes premature closing of the valve other positions which enable additional venting can also be utilized. As shown in FIG. 4, the axis of the vent hole in the initial stage of flushing (dotted-line valve A) can be positioned such that the venting of air from the cavity is facilitated. That is, the angle with respect to the central axis of the valve is such that the vent hole faces in a substantially horizontal direction.
The size of vent hole 38 is varied to control the rate at which air is bled or vented from cavity 37 and accordingly the time period for discharge of water from the tank. Thus the size will determine how much water is allowed to drain from tank 10 before the tank valve closes over exit port 36. Typically, the size is chosen to allow only one-half the water in the tank to drain in a standard flush. To empty more than this amount it is merely necessary to actuate and maintain the flush handle so as to keep the tank valve 26 raised for a period of time sufficient to enable all of the water to leave the tank.
In a conventional toilet tank a total time of about 8-10 seconds is needed to drain the contents of tank 10. Thus, by way of example, the hole size could be selected to cause a partial flush by shortening the valve cycle to be about 4-5 seconds. This of course would result in about only one-half the water content of tank 10 being discharged. In a typical flapper-type valve having a conical or tapering float member of about 1 3/4 inches in length and tapering cavity diameter of 1 1/2 inches, a vent hole, by way of example, having a diameter of about thirty-one thousandths (0.031) of an inch will permit closure in about 4 to 5 seconds. Lower portion 29 may of course contain a plurality of vent holes to achieve the desired rate of bleed. The tank valve 26 may be made of any material suitable for toilets, but is typically made from a rubber-like material or soft plastic material.
FIG. 5 shows an adapter means 41 which can be fitted over overflow pipe 20 and to which a tank valve of this invention of the flapper-type can be attached thereto at hinges 27 to become pivotally movable thereon. Adapter means comprises a resilient ring member 42 which is threadably tightened by screw 43.
FIG. 6 shows an embodiment of this invention wherein the tank valve 44 is a modified ball-type valve as opposed to a flapper-type tank valve. The tank valve is comprised of a hollow body portion 160 shown with a flat flange perimeter 61 which essentially divides the body portion into an upper portion 45 and a lower portion 46. The valve contains a cavity 47 therein opening at the base of lower portion 46 at opening 48. Means are attached to the top of the tank valve to which a chain 49 or other suitable lifting connection can be attached. Vent hole 51 is located on the surface of lower portion 46 and extends into cavity 47 to allow air to be vented therefrom. It will be noted that upper portion 45 as shown contains only a minimal void or hollow area. It is found that in modifying conventional ball valves it is generally not possible to place the vent hole high enough in the lower portion to vent sufficient air, and hence permit sufficient water to enter cavity 47, to close the valve prematurely, i.e., before the water in the tank is drained. This owes generally to the larger void volume of such valves. Hence in a preferred embodiment for such valves it is desirable to decrease this overall void volume such that a vent hole in the lower portion can permit premature closing of the valve. As shown, this can be accomplished by constructing the tank valve so as to eliminate the void volume in the upper portion. Typically, flooding (caused by venting air from the cavity) approaching 90% of the volume of the tank valve cavity is necessary to cause premature closing. Since in conventional ball-type valves this would require a vent hole in the upper portion it is therefore preferred to construct the valve such that the predominant void volume resides in the lower portion, i.e., the portion which is adapted to extend within the opening of the valve seat.
In a preferred emboidment of a tank valve of the invention, the vent hole is located at or near the underside intersection of the lower portion and the flange surroudning upper portion such as shown in FIG. 2. The upper portion, of course, serves to prevent water from entering through the vent hole while the tank valve is closed.
The invention further comprises a method for adapting conventional tank valves to permit premature closure thereof by placing a hole in the lower hollow portion of the valve as described herinabove with respect to the valve itself.
Thus the present invention can be seen as providing a simple yet highly effective device for regulating and limiting the amount of water utilized in flushing a tank-type toilet. As such, this tank valve can lead to a significant conservation, and savings, of domestic water supplies, especially in those areas where water is limited. In contrast to prior art devices having a similar purpose, the tank valve of this invention is unique in that the means for expelling the air is positioned in a manner whereby there is no fear of water prematurely entering therein nor resort to complicated devices to insure such a condition.
Since flapper-type valves are the most commonly utilized today it will be appreciated that the present invention is ideally suited therefore. The flapper-type valve according to this invention comprises a hollow circular body portion having a downwardly facing opening at the bottom thereof defining the entrance to the cavity. A flat circular flange extends laterally around the perimeter of the body portion. The flange sits on the valve seat to close the opening therein and serves to divide the body portion into upper and lower portions. The lower portion is adapted to extend into the opening in the valve seat when the flange covers the seat. Means are included for pivotally mounting the valve for movement about a predetermined pivotal axis offset from and at an angle to the central axis of the valve. As with non-flapper valves the vent hole is located in this lower portion, preferably adjacent to the interconnection of the lower portion with the underside of the flange to permit premature closing at some predetermined time. As with non-flapper valves, the axis of the vent hole can be disposed at a predetermined angle to the central axis of the valve extending through the upper and lower portions.
While this invention has been described with respect to certain preferred embodiments, it will be appreciated by those skilled in the art that various modifications and alterations may be made without departing from the scope and spirit of this invention as defined by the appended claims.
|
Disclosed herein is a tank valve for tank-type toilets comprised of a closed upper portion adapted to extend across the opening of a valve seat, and a hollow lower portion extending downwardly from adjacent the upper portion and adapted to extend within the opening of the valve seat. The lower portion is provided with a vent hole to permit air to escape therefrom to counteract the normal buoyancy of the tank valve. Such an arrangement allows the tank valve to close and terminate the flush without having to utilize the entire supply of flush water contained in the toilet tank.
| 4
|
BACKGROUND OF THE INVENTION
This invention relates broadly to methods and apparatus for removing previously applied floor tile mastic, and particularly with the removal of such mastic materials where those materials may contain asbestos or other hazardous waste.
For many years, the floors of various kinds of buildings such as schools, grocery stores, hospitals, factories and the like have been covered by floor tile so as to present an easily maintained decorative surface. The floor tile is typically composed of a matrix of particles and/or fibers bonded together by a continuous resinous component. The continuous component is typically a bituminous or vinyl base material. The particulate and/or fibrous filler can include a wide variety of materials including particles composed of the same or other resinous materials, extenders such as gypsum and mica, softening agents such as oils and waxes, and fibrous components to enhance the cohesive properties of the tile such as fiberglass and asbestos. Use of asbestos in floor tile has largely been curtailed due to the hazard presented by such substances. Nevertheless, a significant amount of tile already present in the environment does contain such asbestos fibers.
From time-to-time, it becomes desirable to replace an existant tile floor, or portions thereof, due to wear, to change of decorating colors, to go to a wholly new type of floor covering such as carpeting, or merely to eliminate the hazard presented by the asbestos containing materials. The removal of the tile from the floor can be done mechanically by inserting a tool between the floor tile and the floor. Typically, such a removal causes the tile to be broken into a number of pieces which is of little or no concern unless the tile contains asbestos fibers. Where the tile is asbestos fiber containing, such breaking of the tile might permit airborne release of asbestos fibers. Such removal of the tile also disturbs the mastic which bonds the tile to the floor. Such mastic may be contaminated with or otherwise contain asbestos fibers which again may be released into the air during such activity.
A number of statutes and agency regulations have been adopted to deal with the removal of asbestos containing floor tile to prevent the release of the asbestos into the environment. These statutes and regulations generally require that the work area be isolated from the environment, typically by the installation of plastic sheeting acting as a particulate barrier. Workers within the work area must be dressed in protective gear and wear respirators to prevent their own exposure to the material. Appropriate decontamination areas must be provided for the workers. The removed material must be disposed of in a compliant manner in order to minimize release of the asbestos into the environment. All of these steps substantially increase the time and cost of the removal of such tile. The complete removal of the mastic is further complicated by its tenacity to the floor itself thereby tempting many to delay the removal of such materials until absolutely required.
While certain advancements in the removal of asbestos tile have been developed such as those disclosed in U.S. Pat. No. 4,983,809, there has been little consideration for the development of a low cost means of removing asbestos containing or contaminated tile mastic from a floor subsequent to the tile removal. It is therefore a primary object of the present invention to provide a method and apparatus for removing tile mastic from a floor subsequent to the removal of the tile itself in a manner which eliminates the release of asbestos particles into the air.
SUMMARY OF THE INVENTION
In accordance with the present invention, a movable enclosure is provided which can be quickly and easily positioned to encompass any selected area of a floor where the safe removal of asbestos containing floor tile mastic is desired. The selected area of the floor within the enclosure is then contacted with a quantity of liquid sufficient to wet the asbestos containing material in the selected area. A flow of air is established into the enclosure adjacent to the floor and out of the enclosure through a filter means. The floor tile mastic on the floor is then scoured while the flow of air is continuing. The amount of liquid and air into and out of the enclosure is monitored continuously to insure the adequacy thereof. The scouring of the floor mastic is immediately inhibited in the event the amount of liquid or air falls below certain preselected values.
Most conveniently, this process is carried on by a single unit apparatus for removing floor tile mastic from a floor. The apparatus comprises a platform and support means for supporting the platform above a floor having floor tile mastic thereon. A motor means is mounted on the platform and a scouring means is coupled to the motor means for movement with respect to the platform and the floor. A conduit means is provided for supplying liquid to the floor in the vicinity of the scouring means. A shroud means surrounds the scouring means, and a plenum means is coupled to the shroud means to define a chamber through which air can be drawn. A vacuum means coupled to the plenum means draws air between the shroud means and the floor, and through the plenum means. A filter means coupled to the vacuum means filters the air passing through the plenum means. A first control means coupled to the conduit means and the motor means inhibits the operation of the motor means in the absence of liquid supplied to the floor in the vicinity of the scouring means. A second control means is coupled to the vacuum means and to the motor means for inhibiting operation of the motor means in the absence of a flow of air through the filter means.
One feature of the present invention is the provision of a small area movable enclosure within which all work is confined. The work within the movable enclosure is directed by workers, all of whom are located outside the enclosure area. This feature has the advantage of removing the worker from the hazardous material area thereby eliminating the need for awkward and bulky clothing, decontamination areas, and so forth. The removal of the worker from the hazardous work area permits a more timely and low cost removal of the mastic from the floor.
Another feature of the present invention is the control means for inhibiting the operation of the motor means in the absence of an adequate liquid supply to the floor. This feature has the advantage of insuring that any asbestos fiber or other potentially harmful material in the floor tile mastic will be thoroughly wetted with liquid thereby significantly reducing the chance for airborne release of the material. In a preferred embodiment, a liquid level alarm means is provided which can alert the operator of a low level of liquid thereby permitting the operator to replenish the same in advance of any difficulty.
Yet another feature of the present invention is a control means for inhibiting the operation of the motor means in the absence of an adequate flow of air through the filter means. This feature insures that any airborne release of material will be confined within the enclosure and will be drawn through the filtering means which is a high efficiency particulate (HEPA) filter system. Thus, the floor tile mastic removing apparatus cannot be operated unless the filtering equipment is operational to prevent release of asbestos fibers into the environment.
In the preferred embodiment, the second control means includes a plurality of manometers measuring the vacuum on either side of the filter means and circuit means for determining the efficiency of the filtering means. Such a control means directly ties the continual operation of the apparatus to the filtering efficiency thereby assuring that workers are not exposed to any hazardous situation. The control means also alerts the operator in advance of the need for maintenance of the filtering system of the equipment prior to any significant degradation in filtering performance.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived. The detailed description particularly refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view partially broken away of an apparatus constructed in accordance with the present invention.
FIG. 2 is an elevation view of the face of the electrical control panel.
FIG. 3 is a schematic line diagram showing the various control means for the present apparatus.
FIG. 4 is a perspective view of an alternative embodiment of the present invention.
FIG. 5 is an elevation view of the control panel on the embodiment shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A floor tile mastic removal apparatus 10 is shown in FIG. 1 positioned on a floor 12. The apparatus 10 comprises a main platform 14 supported on a trailing leaf suspension system of known design on a pair of wheels 18 (only one of which is shown). A motor 20 is fixed to the platform by a plurality of fasteners 22 such that the driven shaft 24 of the motor projects downwardly to engage spur gear 26 within gear housing 27. The spur gear 26 engages one or more driven gears 28 each of which are keyed for rotation about a corresponding driven shaft 30. A lower end of the driven shaft 30 is fixed to a driving spider 32 which is in turn connected to a drive head 34 through wobble plate 36. The drive head 34 includes a plurality of downwardly facing cups 38 adapted to receive replaceable scouring elements 40.
An inner shroud 42 projects downwardly from the platform to surround the spider 32 and wobble plate 36. An outer shroud 44 projects downwardly from the platform 14 to surround the inner shroud 42 and the area of the scouring head 34. A skirt 46 surrounds the lower perimeter 45 of shroud 44 and is vertically movable with respect to shroud 44 over a limited distance by virtue of an elastic band 47 confining the space between the skirt 46 and the shroud 44 around the entire circumference of shroud 44 and skirt 46 with a retaining chain 48.
The space existent between inner shroud 42 and outer shroud 44 defines a plenum 50 through which air can be drawn upwardly past the gear enclosing portion 27 of platform 14 to an enclosed volume or chamber 51 extending from front wall 52 rearwardly to a rear wall 54. The chamber 51 is further defined by side walls 56 and 58, and is completed by platform 14, a forward top wall 60, a rearward top wall 62 and a vertical partition wall 64 joining walls 60 and 62.
A vacuum means 69 having an exhaust outlet 66 rests on and is coupled to the top wall 62. The vacuum means 64 draws air through an opening 63 in top wall 62. The air is drawn below the skirt 46 in the direction of arrow "A" upward through plenum 50, into the chamber 51, into contact with and through filter 68. The filter 68 is a high efficiency particulate (HEPA) filter certified for use in connection with the handling of asbestos materials and intended to retain any airborne asbestos particles within the enclosed chamber 51. It will be appreciated that the filter 68 is a replaceable element which must be maintained in suitable working order for the apparatus 10 to perform the intended function. The volume of air drawn upward by the vacuum means 64 must be sufficient to insure an inward flow of air around the entire perimeter of skirt 46 during operation of the apparatus 10 thereby inhibiting any outward dispersal of particulate matter or airborne materials.
A liquid reservoir 70 is mounted to surround the forward perimeter of motor 20 and includes a cap 72 to permit the introduction of liquid into the reservoir. In general, the liquid employed in the operation of the present invention is merely water but can include certain surfactants which might enhance the fiber wetting capacity of the water but at the same time not adversely affect the character of the scouring elements 40 as they work on the mastic on floor 12. A control valve 74 controls the delivery of liquid from the reservoir 70 to conduit 76. The conduit 76 projects downwardly from valve 74 into the immediate vicinity of the drive head 34 to supply liquid to the floor in the vicinity of the scouring operation.
The apparatus 10 is manually directed to a desired location through the use of a handle 80 fixed to platform 14 by means of standards 82. An electrical control housing 84 is fixed to standards 82 and contains the various electrical control circuitry for the apparatus. An instrument panel 86 is provided immediately adjacent to handles 80 so as to be within the convenient reach of an operator and to be positioned for easy and continuous reference by the operator.
The control panel 86 is shown in FIG. 2 while the circuitry below that panel is shown in FIG. 3. A main on/off power switch 88 connects the circuit with an outside source of power through power input jack 89. The main power switch includes an emergency stop push button 90 connected to the main power switch 88 to allow quick shut-off of the apparatus 10 in the event of an emergency. When the main power switch 88 is turned on, power is permitted to flow to a logic display power supply 92, with switch 94 controlling the delivery of power to motor 20, and switch 96 controlling the delivery of power to motor 98 of the vacuum means 64.
The switch 94 controlling power to motor 20 is actuated by start push button 100 and by stop push button 102. The delivery of power to the motor 98 by switch 96 is similarly controlled by start push button 104 and by stop push button 106. It is to be noted that with the main power switch 88 on, power can be delivered directly to motor 98 through actuation of the start push button 104. On the other hand, actuation of start push button 100 will not deliver power to motor 20 unless relays 108 and 110 are appropriately actuated.
Relay 110 is connected to a first control means 112 which is in turn connected through display 114 to a water level sensor 116 located within reservoir 70. The flow of water from reservoir 70 is controlled by valve control 118 and light signals 120 and 122, which are respectively green and red, indicate the delivery of water from reservoir 70 through conduit 76. As long as sensor 116 senses an adequate display of water within reservoir 70 and valve control 118 is situated so as to guarantee a flow of water, then relay 110 is maintained in a closed position permitting power to flow through to motor 20. In the event the valve control is moved to a position providing an inadequate flow of liquid or sensor 116 senses an inadequate supply of liquid, then relay 110 opens depriving motor 20 of power and sounding alarm 124.
Relay 108 is connected to a second control means 126 which is in turn connected through displays 128 and 130 to manometer sensors 132 and 134. Sensor 132 is located within chamber 51 to sense that pressure within that chamber and provide information to the display 128 relative to that pressure. The display 128 includes a visual read out 136 of the pressure as well as red and green lights 138 and 140 indicating unsatisfactory and satisfactory performance, respectively.
In a similar manner, sensor 134 is situated within the housing of the vacuum means 64 above filter 68 to sense the air pressure on the opposite side of filter 68 from that sensed by sensor 132. Display 130 coupled to sensor 134 includes a visual display 142 of the pressure within the housing of vacuum means 64 and red and green lights 144 and 146 indicating satisfactory and unsatisfactory performance of the vacuum means 64, respectively.
An output from display 128 and 130 is coupled to the control means 126 providing the control means with the information relating to the pressure on both sides of filter 68. As long as the vacuum in enclosure 51 is adequate and the difference in vacuum between enclosure 51 and vacuum means 64 is not so large as to indicate the need for a change of filter 68, then relay 108 is maintained in a closed position. In the event that either sensor 132 or 134 senses too small a vacuum, or the difference in vacuum sensed indicates a need for a change in filter 68, then relay 108 is opened depriving motor 20 of power and alarm 124 is actuated.
A second embodiment of a floor tile mastic removal apparatus 210 is shown in FIG. 4. The apparatus 210 comprises a main platform 214 supported on a plurality of wheels 218. A motor is situated within housing 219 which is fixed to the platform 214. The driven shaft of the motor is coupled to a flexible shaft 223 which extends outwardly to a scouring head 234 within shroud 244. The scouring head 234 includes a single replaceable scouring element 240. The shroud 244 includes a handle 280 which is used to move the scouring head 234 to a desired work location remote from the platform 214.
The space existent between the scouring element 240 and shroud 244 defines a plenum through which air can be drawn through vacuum line 250 to an enclosed volume or chamber 251 on platform 214. A vacuum means 264 having an exhaust outlet 266 rests on and is coupled to the top of chamber 251. The vacuum means 264 draws air in the chamber 251 into contact with and through a filter, a high efficiency particulate (HEPA) filter certified for use in connection with the handling of asbestos materials and intended to retain any airborne asbestos particles within the enclosed chamber 251. It will be appreciated that the filter is a replaceable element which must be maintained in suitable working order for the apparatus 210 to perform the intended function. The volume of air handled by the vacuum means 264 must be sufficient to insure an inward flow of air around the entire perimeter of shroud 244 during operation of the apparatus 210 thereby inhibiting any outward dispersal of particulate matter or airborne materials.
A liquid reservoir 270 is mounted on platform 214 and includes means 215 for pressurizing the liquid reservoir 270 and a cap 272 to permit the introduction of liquid into the reservoir. A conduit 276 extends from the reservoir 270 to a valve 274 in the immediate vicinity of the scouring head 234 to supply liquid to the floor in the vicinity of the scouring operation. The control valve 274 controls the delivery of liquid from the reservoir 270 through conduit 276.
An electrical control unit 284 is fixed to housing 219 and contains the various electrical control circuitry for the apparatus. An instrument panel 286 is provided within the convenient reach of, and for easy and continuous reference by, the operator. The electrical control panel 286, shown in FIG. 5, is coupled to circuitry similar to that shown in FIG. 3. A main on/off power switch 288 connects the circuit with an outside source of power. When the main power switch 288 is turned on, power is permitted to flow to the circuitry within housing 219 including switch 294 controlling the delivery of power to the motor driving the flexible shaft 223 coupled to the scouring head 234. It is to be noted that with the main power switch 288 on, power can be delivered directly to the motor driving the vacuum means 264. On the other hand, the delivery of power to the motor driving the flexible shaft 223 coupled to the scouring head 234 will not occur unless relays or other control means similar that discussed in connection with the first embodiment of the invention are appropriately actuated.
A first control means is provided which is connected through display 314 to a water level sensor located within reservoir 270. The flow of water from reservoir 270 through conduit 276 controlled by valve control 274 is indicated by light 320. In the event the valve 274 is moved to a position providing an inadequate flow of liquid or an inadequate supply of liquid is indicated to exist within reservoir 270, power is prevented from flowing to the motor driving the flexible shaft 223 and an alarm is sounded.
A second control means is provided which is connected through display 328 to manometer sensors located within chamber 251 and within the housing of the vacuum means 264 to sense the air pressure on the opposite sides of the HEPA filter. The display 328 indicates the pressure within the chamber 251. In the event that either sensor senses too small a vacuum, or the difference in vacuum sensed indicates a need for a change in filter, then power is prevented from flowing to the motor driving the flexible shaft 223 and an alarm is sounded.
Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and as defined in the following claims.
|
Apparatus for removing floor tile mastic from a floor includes a scouring unit enclosed within a shroud coupled to a plenum through which air can be drawn by a vacuum unit including a HEPA filter. Water or other liquid is delivered from a reservoir to the region of the scouring unit to wet any asbestos fibers in the floor tile mastic. The liquid supply and the flow of air through the filter are monitored and the operation of the scouring unit is inhibited at any time the supply of liquid or the flow of air falls below selected values.
| 8
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods and apparatus for welding by use of high frequency electrical resistance heating and, more particularly, to the welding of brake webs to brake tables to form brake shoes.
2. Description of the Prior Art
Traditionally, brake shoes have been formed by a series of projection welds between the brake table and the brake web. This has been accomplished by providing projections on a flat plate or table to concentrate the power flowing through the web. The web and the table are rolled together and resistance welded at the projections. The projections provide the metal that forms the weld to hold the brake shoe together. In the present invention, there are no projections. In the present invention, each brake web has a die break which can be defined as a small angular projection of metal which has been left by the die in the machine which stamps out the curved web pieces from flat metal plate. During welding the die brake melts and is forced into contact with heated metal of the brake table to provide most of the metal for the weld.
If one were to attempt to utilize the old method of resistance welding to form a continuous weld as is formed in the brake shoe of the present invention, two deleterious conditions would occur. First, the tremendous amount of heat required would melt so much of the web metal that the outer radius of the web would lose its shape thereby distorting the final brake shoe. In addition, the heat required would melt so much of the metal in the brake table that the thickness of the metal in the table under the web table interface would be greatly reduced. The combination of these two effects would result in a brake shoe that had a weaker web table weld interface than a brake shoe made by a series of projection welds of the same type.
By using a high voltage radio frequency current, a continuous weld of fused metal from the table and the web can be produced without any of the deleterious effects that occur in the prior art. Since the use of high frequency (200,000 Hz or more) versus the low frequency (60 Hz) prior art resistance welding brings about current densities in the order of 1 million watts per cubic inch at the weld point between the web and the table heating can be localized. When the localized heating is coupled with a rapid controlled advance of the weld point, the amount of fusion between the web and the table and the resultant melting thereof can be very closely controlled. The weld of the present invention uses only the die brake on the web, which is about 0.017 inches, as the metal utilized for fusion. Therefore, the dimensions of both the table and the web remain relatively unchanged.
It is not desirable to use arc welding in making brake shoes since this requires fillet welds on either side of the web-table interface. These fillets (usually 3/16") may impinge on the rivet holes which are placed relatively close to the web to enable the braking material to be riveted on the brake shoe. Also, in a brake shoe with two webs, as is the case in the preferred embodiments discussed below, it is difficult to position two weld electrodes within the space between the two webs. In addition, the extra cost of slow weld speeds, weld wire and shield gas must be considered.
As will be better described below, the welds produced by the present invention are of superior strength when compared to the prior art resistance welding methods.
There are many examples of prior art devices which utilize radio frequency welding to form various continuous welds of strips and the like. U.S. Pat. No. 2,821,619, issued Jan. 28, 1958 to W. C. Rudd discloses the basic method of using high frequency electrical resistance to weld a continuous strip for a metal flange.
U.S. Pat. No. 3,513,284, issued May 19, 1970 to J. N. Snyder discloses an apparatus which uses high frequency resistance heating for welding an edge of a web member to the face of a flange member to form a long structural shape. This apparatus cannot be used for the welding of short sections as is the apparatus of the present invention.
U.S. Pat. No. 3,375,344, issued Mar. 26, 1968 to F. Kohler et al discloses a method and apparatus for simultaneously welding elongated metal members together at two spaced weld points using high frequency electrical current. Again, the apparatus disclosed is used to weld structural shapes out of long strips of metal and not short pieces as in the present invention.
U.S. Pat. No. 3,391,267, issued July 2, 1968 to W. C. Rudd also shows an apparatus for welding long strips to form structural shapes such as I beams. This patent also discloses a method of welding finite length flange sections to the web as long as the flange sections are in end to end contact. If this were not the case, as the patent points out, there would be weld interruptions or irregularities in the weld seam and a foot or more of the welded beam structure would have to be cut off and wasted where the trailing and leading ends of the successive strip pieces pass through the welding zone. In the present invention, the entire weld length may be no more than 14 inches and the method described below must be used to insure that a high quality weld is formed almost to the end of the brake table brake web interface.
SUMMARY OF THE INVENTION
It is an object of this invention to provide high frequency resistance heating apparatus which will efficiently concentrate heat along the weld path of a relatively short flange member to which is welded the edge of a relatively short curved web member.
Another object of this invention is to provide improved high frequency resistance heating apparatus which will permit the welding of brake shoes more rapidly than presently known brake shoe welding apparatus.
It is an additional object of this invention to provide a high frequency resistance heating apparatus which will efficiently concentrate heat along the weld path of a relatively short brake table to which is welded simultaneously the edges of two curved web member having a relatively short length.
It is a further object of this invention to provide a high frequency resistance welding apparatus and method which will permit the welding of relatively short flange and web pieces which produce a high quality weld almost to the end of the flange web interface.
It is yet another object of this invention to provide an automotive brake shoe having at least one web which has superior weld strength at the web table interface compared to prior art resistance welded automotive brake shoes.
It is a still another object of this invention to provide a high frequency resistance welding apparatus which will simultaneously weld a brake table and a brake web to one another while simultaneously shaping the brake table to conform to the correct curvature required for the brake shoe.
It is yet another object of this invention to provide a high frequency welding apparatus in which the forces used to force the brake table into contact with an electrical conductor are transmitted mechanically through a pivoting arrangement to cause a second conductor to contact the brake web prior to welding.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of certain preferred embodiments thereof which in conjunction with the accompanying drawings in which:
FIG. 1 illustrates a schematic of the automatic welding apparatus of the present invention;
FIG. 2 illustrates a brake web welded by the method and apparatus of the present invention;
FIG. 3 is an elevational view of the hold down method of the present invention;
FIG. 4 is an end on view of the apparatus of FIG. 3;
FIG. 5 is a cut away view of the brake shoes mounted on the fixture of FIG. 3 showing various positions of rotation of the fixture;
FIG. 6 is an elevational view of the apparatus for transferring electrical power to the brake shoes;
FIG. 7 is a isometric view of the preferred brake shoe of the present invention; and
FIG. 8 is a sectional view of the brake web of the present invention prior to welding.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a schematic view of the radio frequency welding system of the present invention which is generally denoted as 10. As indicated above, radio frequency welding systems are well known in the prior art. These welding systems generally consist of a radio frequency oscillator power supply 12 which feeds a radio frequency transformer 14 through primary conductors 16 and 18. Secondary conductors 20 and 22 convey the power from the transformer to the workpieces. In the present invention, the secondary conductors 20 and 22 are connected to both the brake web 24 and the brake table 26 respectively via a web ring contactor 27 and a table contactor 29.
Specifically, the conductors consist of a brake table conductor 22 which conducts power directly from the transformer to the table contactor 29 then to the brake table 26 and a web ring conductor 20 which conducts power to a web ring contactor 27 and then into a web contactor ring 28 which abuts the brake shoe web 24.
In the preferred embodiment, the radio frequency oscillator 12 and the radio frequency transformer 14 are situated in close proximity to minimize the length of the primary conductors 16 and 18. It has been found that power losses are greatly reduced if the length of the conductors 16 and 18 are kept at a minimum. Similarly, the location of the fixture for holding the brake web and the brake table for welding is located in close proximity to the radio frequency transformer 14 to minimize the length of the secondary conductors 20 and 22. In the preferred embodiment both the primary and secondary conductors are made of copper. Additional details of the secondary conductor will be described more fully below.
In the preferred embodiment, the oscillator 12 is a 150,000 kilowatt oscillator that converts 480 volt, 60 cycle alternating current to 1,300 volt, 300,000 cycle alternating current. The preferred frequency for operation will always be in the high frequency range between 200,000 cycles and 500,000 cycles.
The preferred brake table contactor 29 and the web ring 28 engage the brake shoe web 24 and the brake shoe table 26 after they have been located on a fixture 30. The fixture 30 has at least one slot 32 therein to receive and index the brake web 24. The fixture 30 also has a locating element 34 which stops the brake shoe table 26 when it is being fed onto the fixture and correctly positions it with respect to the brake web 24 to insure that the brake web and brake table are welded together in a proper position. In the preferred embodiment, the brake table 26 is initially flat although this is not necessary. The brake web, on the other hand, has a curvature equal to the desired curvature of the finished brake shoe. Thus, when the brake table and brake web are fed into the fixture such that one end of brake table 26 abuts one end of brake web 24, a diverging gap will be produced with its vertex at the abutting point between the brake table and the brake web. It is necessary to maintain a diverging gap during the welding operation since the power from the radio frequency oscillator will be concentrated at the vertex between the brake shoe table and web causing the heating thereof and consequent welding.
As can be seen in FIG. 3, a finger like hold down fixture 36 is provided. The hold down fixture 36 is positioned with respect to the contact area between web 24 and table 26 such that when welding is started and fixture 30 rotates in the direction marked A on FIG. 3, the hold down fixture provides initial deflection of the brake table to insure that after welding the finished brake shoe has the correct curvature. The hold down fixture 36 need be provided for only 2 or 3 inches beyond the weld point since by that distance the weld between the brake web 24 and the brake table 26 is strong enough after cooling to keep those two parts together. If the hold down fixture 36 were not provided, the weld would tear immediately after the brake web and brake table pass beyond the forge wheel 38. If two brake webs 24 are utilized, as is the case with the preferred brake shoe shown in FIG. 7, two hold down fixtures similar to that shown in FIG. 5 would be used and the hold down fixtures would be positioned along the brake table outboard of the webs.
In addition, FIG. 3 shows the support means for the forge wheel 38 and the hold down fixture 36. The support means consists of a frame 81 which may be mounted to the base of the support structure for the entire machine. A forge wheel support arm 82 is pivotally mounted to the support 81 to allow the forge wheel 38 to move in the vertical direction. The forge wheel 38 can be moved vertically up and down by a hydraulic system (not shown). The hold down fixture 36 is also pivotally mounted on the support structure 81. In the preferred embodiment, a bolt 84 is threaded through the arm 82 to contact the hold down fixture 36. The bolt 84 transmits the hydraulic force applied to forge wheel 38 to the hold down fixture 36 to insure clamping between the brake table 26 and the brake web 24. The bolt 84 may be adjusted in the vertical direction to insure proper engagement of the hold down fixture 36. A spring 86 is provided to lift the hold down fixture 36 out of engagement with the brake shoe when the forge wheel 38 moves in the vertical direction out of engagement with the brake shoe table 26.
FIG. 5 shows two brake shoes mounted on fixture 30. In the preferred embodiment, the method of welding the brake web 24 to the brake shoe table 26 involves automatically feeding the web and table onto the fixture 30, welding the two pieces together as fixture 30 rotates in the A direction and removing the finished brake shoe after welding is completed. As the weld ends on brake shoe 40 the fixture rotates slightly, as will be described below, to accommodate the loading of the brake web and brake table for brake shoe 42.
As can be seen in FIG. 5, the web 24 for brake shoe 40 is loaded onto the stationary fixture 30 when point one is at the arrow. The fixture 30 clamps the web 24 and then rotates so that point two is at the arrow and then the table 26 is fed in to stop 34. Rotation at this time is delayed until after the forge wheel 38 is lowered against the table 26. This action also forces it into contact with the contactor 29 at the end of the secondary conductor 20.
The power builds up taking between 0.05 and 2 seconds until reaching the operating levels set forth above. On reaching the operating level, fixture 30 again begins to rotate so that a continuous forge weld is formed between the brake web 24 and the brake table 26. This welding continues until point three is at the arrow on FIG. 5 at which time the rotation of fixture 30 is stopped. In the preferred method of welding the brake web to the brake table, the power is maintained for a predetermined time, approximately 0.05 to 2 seconds, after fixture 30 has stopped rotating. After this time delay, the power is shut off and decays exponentially and, upon reaching a relatively low level after approximately 0.05 to 2 seconds, rotation of the fixture 30 again begins to where point four is at the arrow, the forge wheel is retracted and the web 24 and brake shoe 42 is loaded. After this time, the brake shoe 40 is removed from the fixture 30 while the fixture rotates between points four and five. Point five would be the point at which the table for brake shoe 42 is loaded and the point at which welding between the brake shoe web 24 and the brake table 26 and brake shoe 42 begins. The welding of brake shoe 42 would continue until point six is at the arrow. The process would then be continually repeated as set forth above to enable the high speed welding of the brake shoes.
The above described method, including time delays, for welding the brake web 24 to the brake table 26 results in an excellent weld as close as approximately 1/2 inch from the end of the brake table. The prior art has mainly concerned itself of long structural shapes such as "I" beams or tubing whereas the present invention teaches a method for welding relatively short finite parts with a typical embodiment having a weld of 16 inches. The length of the time delay must be accurately predetermined to insure the strength of the weld at the beginning and end of the finite length described above. A short time delay will cause a weak start on the weld. Too long a time delay will cause excessive melting of the web cross section which not only will produce a weak weld but also cause the metal to flow along the sides of the brake web and brake table interface which would cause drop like projections 25 shown in FIG. 2. These drop like projections, if extending along the brake table surface for too great a distance, would cause interference during other operations such as riveting the brake lining to the brake shoe. In the present invention, these drop like projections are minimized and extend no more than 1/8 inch along the brake table surface. This is well within the limits required to avoid interference during brake shoe lining assembly.
FIG. 6 provides a detailed view of the method for conducting power to the brake web 24 and the brake table 26. Power is conveyed from the high frequency transformer 14 through the secondary conductors 20 and 22. The secondary conductors 20 and 22 are composed of a first flexible portion 46 and 48 respectively and a second rigid portion 50 and 52 respectively. The rigid portions 50 and 52 are pivotally connected by a clamp support 54 which has two pivot points 56 and 58. The rigid conductor 50 pivots about point 56 and the rigid conductor 52 pivots about point 58. A spring 60 is positioned between rigid conductor 50 and 52 at an end thereof away from the welding area. The spring 60 acts to move the table contactor 29 which is attached to rigid conductor 52 into engagement with the table 26. The spring also moves the web ring contactor 27 which is attached to rigid conductor 50 into engagement with the web ring 28. The no load height adjustment screw 64 is provided to adjust the height of the table contactors 29 so that the table can feed over the contactors before the forge wheel is brought down. In addition, the adjustment screw provides a preload force therebetween the web ring and the web ring contactor. The force of table 26 against the table contactor 29 pivots contactor 52 around pivot point 58 pressing spring 60 which, in turn, pivots rigid conductor 50 about pivot point 56 forcing the web ring contactor 27 into engagement with the web ring 28 with greater force than achieved with the preload screw.
In the preferred embodiment, the web ring 28 contacts the brake shoe web over the entire radial length of the web. The web ring 28 rotates with fixture 30 as the web is rotated past the weld point between the web 24 and table 26. At any point after the loading of the webs onto fixture 30, the web ring contactor 28 is forced into positive electrical contact by pneumatic, mechanical or hydraulic means (not shown) located within fixture 30. A high contact force between the web ring 28 and the web 24 is required to insure no arcing between the contacting surfaces. This arcing may occur because of the lubricant film which is present on all of the electrical contact surfaces due to the design of the machine. It has been found that a contact force of 25 to 40 pounds per square inch between the contacts is required to insure no arcing between contacting surfaces. If arcing were to occur, the life of the electrical contacts would be substantially reduced. In addition, contact forces of between 25 and 40 pounds per square help overcome minor surface irregularities between the contacting surfaces which also would contribute to arcing problems.
The initial load between the web ring contactor 27 and the web ring 28 can vary between the slight gap, consequently no force, and 1/2 pound per square inch. As stated above, a pressure of between 25 and 40 pounds per square inch is required to insure positive electrical contact. Since the welding system described herein requires positive electrical contact to insure induction of electrical power without arcing, the term "contact" used herein denotes contact between conductors with a pressure of between 25 and 40 pounds per square inch rather than mere touching.
The flexible conductors 46 and 48 are tied into the rigid contactors 50 and 52 respectively in the area of the pivot points 56 and 58 which enables the use of flexible conductors which flex only about 2 degrees at the ends connected to the rigid conductors 50 and 52 while motion at the end of conductors 50 and 52 may be as much as 1/2 inch. In the preferred embodiment, layers of copper sheet soldered together at their ends are used to form flexible conductors 46 and 48. It should be noted that insulation (not shown) separates flexible conductors 46 and 48 and rigid conductors 50 and 52. This prevents arcing of power between the conductors and the resultant short circuit effects. In the preferred embodiment, the conductors are separated by sheets of Teflon, a registered trademark of the E. I. DuPont Company, approximately 1/8 inch thick. The Teflon insulation would be present at all points between the conductors. In addition, the clamp support 54 with its pivot points 56 and 58 is made out of a non electrically conductive material. In the preferred embodiment, the support assembly 54 is machined out of Delrin block.
FIGS. 2 and 7 show brake shoes 72 and 74 which are welded by the apparatus and method of the present invention. The only difference between FIGS. 2 and 7 is that FIG. 2 shows a brake shoe having one web 24 and FIG. 7 shows a brake shoe having two webs 78 and 80. In both cases, webs 24 are welded to the brake tables 26 by a continuous weld produced by radio frequency current. The above description deals mainly with the welding of one web to a brake table. If it is desired to weld two webs simultaneously to a brake table, the schematic of FIG. 2 would have to have a mirror image about the center line of the brake table 26. This would mean that a second set of oscillators, transformers, primary conductors, secondary conductors and table and web contactors would be required. One fixture 30 and one forge wheel 38 could be utilized to handle either one or two webs.
If two webs were desired, there would have to be two table contactors 29 each located outboard of its adjacent web. Two web ring contactors 27 and two web rings 28. would be required. The web ring 28 would also be located on the outboard side of each web 24. The web ring 28 could theoretically be located on the inside of the webs 24 except that in practice the room between the two webs is usually sufficient to permit insertion of two contactors.
In the preferred embodiment, the brake shoe webs 24 and the brake shoe tables 26 are fed onto fixture 30 automatically. This automatic feeder could be either air or hydraulically operated in that a pusher arm (not shown) would push each web into engagement with the web fixture 30 while a similar pusher arm would push the brake table 26 against the stop on the fixture 30. Due to the high voltage required and the high current densities involved in the above welding process, it would not be safe to feed the brake webs and brake tables by hand. The use of an automatic feeder and the indexing described above for making the radio frequency weld easily lends itself to electronic controls that enable the whole process to be fully automated. Thus, the apparatus of the present invention is able to produce far more brake shoes in a given time than were possible with several semi-automatic operated machines of the prior art. Specifically, an entire brake shoe can be loaded, welded and removed from the machine in 6 to 8 seconds.
Welds produced by the apparatus and method described above, being continuous, provide a far superior bonding between the brake web 24 and the brake table 26. Destructor tests run on brake shoes manufactured by the method of the present invention have failed by shearing the material of the brake table approximately 1/2 inch from the weld joint over the whole length of the weld. In contrast, brake shoes manufactured under the prior art resistance welding failed by shearing the weld at each of the projection welds. An additional advantage of a continuous weld is that no reinforcement arc welding of defective projection welds is necessary as was performed under the prior art when a poor weld was detected. This was done because one defective projection would substantially reduce the strength of the joint between the brake table and the brake web. The brake shoe of the present invention, having a continuous weld made with high voltage, high energy would not suffer from a defective weld in one small area. Surface impurities on the web or table decompose and are flushed out in the metal expulsion. The increased strength of the brake shoe produced by the present invention is due to the fact that 70 to 80% of the cross section of the web has fusion and this 70 to 80% continues for the entire weld length. To obtain the same effect in the area of the projection welds of the prior art, an excessive amount of weld heat would have had to been used.
An additional advantage of utilizing the high power density inherent with radio frequency welding is that the 70 to 80% weld across the thickness of the web is achieved without distorting the brake shoe table as much as the prior art. The table stays flat along its width to within 0.020". Also, the prior art projection welded brake shoes had humps due to the welded projections which could not always be taken out by a "coining" operation.
FIG. 8 shows a cross section of the brake web 24 prior to the welding operation of the present invention. As is the case with most brake webs and brake tables, it has been stamped out of a flat plate which has a thickness in the preferred embodiment of about 0.320 inches. As can be seen from the figure, a die brake, or projection 66 remains after the stamping operation. In the prior art the die break would encourage misalignment of the table to the webs by causing the table projections to shift to the side before meeting. Utilizing a high frequency method of welding, the die brake acts to concentrate the current at the vertex between the brake web 24 and brake table 26 and further provide metal to form the weld between the brake web and the brake table. While the above welding method does not require a projection 66 for success, the die brake 66 enhances the weldability of the brake table and the brake web rather than being deleterious as it was in the prior art.
It will be apparent that the invention herein disclosed is well calculated to achieve the benefits and advantages hereinabove set forth, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the spirit hereof.
|
A method and apparatus for welding an edge surface of a curved metal brake shoe web to a metal brake shoe table surface. The metal brake shoe table surface has a greater radius of curvature than the brake shoe web edge. The brake shoe table is positioned in longitudinal alignment with the brake shoe web with one end portion of the table surface abutting the brake shoe web surface over a predetermined distance and with the table surface diverging away from the brake shoe web edge surface forming a vertex where the surfaces abut. The abutting surfaces are pressed together at the vertex thereby moving the diverging surface of the brake shoe table into contact with a first conductor which is spaced from the vertex. A positive electrical connection is provided between the brake shoe web and the second conductor. The second conductor is mechanically interlocked with the first conductor so that the pressure on the first conductor by the pressing action causes the positive electrical connection between the second conductor and the web. A high frequency alternating potential is then provided to the electrodes contacting the table and the web to induce current to flow therebetween and thereby heat the interfacing surfaces in the area of the vertex. The brake shoe table and the brake shoe web are rotated together along a curvelinear path while pressure and the high frequency heating is maintained. This results in the welding together of the interfacing surfaces.
| 5
|
CROSS-REFERENCES TO RELATED PATENT APPLICATIONS
This is a Continuation Application of application Ser. No. 11/873,282, filed Oct. 16, 2007; which is a Continuation Application of application Ser. No. 10/612,013, filed Jul. 3, 2003, and issued on Nov. 6, 2007, as U.S. Pat. No. 7,292,657; which is a Continuation Application of application Ser. No. 09/703,649, filed Nov. 2, 2000, and issued Jan. 20, 2004, as U.S. Pat. No. 6,680,975; which is a Continuation Application of application Ser. No. 08/024,305, filed Mar. 1, 1993, and issued on Jul. 17, 2001, as U.S. Pat. No. 6,263,026; the disclosures of which are incorporated herein by reference. One (1) Reissue application Ser. No. 10/609,438, filed on Jul. 1, 2003, of U.S. Pat. No. 6,263,026 has been abandoned. Continuation application Ser. No. 12/338,647, filed Dec. 18, 2008 is a Continuation Application of Ser. No. 11/873,282, filed Oct. 16, 2007. Continuation application Ser. Nos. 12/343,797, 12/343,839, and 12/343,898, all filed on Dec. 24, 2008, are Continuation Applications of Ser. No. 11/873,282, filed Oct. 16, 2007.
FIELD OF THE INVENTION
The present invention relates to a signal compressing system. A system according to the present invention is particularly suited for compressing image signals. The present disclosure is based on the disclosure in Korean Patent Application No. 92-3398 filed Feb. 29, 1992, which disclosure is incorporated herein by reference.
BACKGROUND OF THE INVENTION
Image signals may be compressed by motion-compensated interframe discrete cosine transform (DCT) coding such as is defined by a MPEG (Moving Picture Expert Group) international standard. This form of signal compression has attracted much attention in the field of high definition television (HDTV).
FIG. 1 is a block diagram of such a conventional motion-compensated interframe DCT coder. In the shown coder, an image signal is divided into a plurality of sub-blocks. The sub-blocks are all of the same size, for example 8×8, 16×16, . . . A motion estimator 40 produces a motion vector, defined by the difference between the current image signal and a one-frame delayed image signal, output by a frame memory 30 . The motion vector is supplied to a motion compensator 50 which compensates the delayed image signal from the frame memory 30 on the basis of the motion vector. A first adder 8 a serves to produce the difference between the present frame and the delayed, motion compensated frame. A discrete cosine transform portion 10 processes the difference signal, output by the first adder 8 a , for a sub-block. The motion estimator 40 determines the motion vector by using a block matching algorithm.
The discrete cosine transformed signal is quantized by a quantizer 20 . The image signal is scanned in a zig-zag manner to produce a runlength coded version thereof. The runlength coded signal comprises a plurality of strings which include a series of “0”s, representing the run length, and an amplitude value of any value except “0”.
The runlength coded signal is dequantized by a dequantizer 21 , inversely zig-zag scanned and inversely discrete cosine transformed by an inverse discrete cosine transforming portion 11 . The transformed image signal is added to the motion-compensated estimate error signal by a second adder 8 b . As a result the image signal is decoded into a signal corresponding to the original image signal.
Refresh switches RSW 1 , RSW 2 are arranged between the adders 8 a , 8 b and the motion compensator 40 so as to provide the original image signal free from externally induced errors.
The runlength coded signal is also supplied to a variable length coder 60 which applies a variable length coding to the runlength coded image signal. The variable length coded signal is then output through a FIFO transfer buffer 70 as a coded image signal.
In motion-compensated adaptive DCT coding, the interframe signal can be easily estimated or coded by way of motion compensation, thereby obtaining a high coding efficiency, since the image signal has a relatively high correlation along the time axis. That is, according to the afore-mentioned method, the coding efficiency is high because most of the energy of a discrete cosine transformed signal is compressed at the lower end of its spectrum, resulting in long runs of “0”s in the runlength coded signal.
However, the scanning regime of the aforementioned method does not take account of differences in the spectrum of the motion-compensated interframe DCT signal with time.
A method is known wherein one of a plurality of reference modes is previously selected on the basis of the difference between the present block and that of a previous frame and the image signal is scanned by way of a scanning pattern under the selected mode and suitably quantized. With such a method, however, three modes are employed to compute the energies of the intermediate and high frequency components of the image signal in accordance with the interframe or the intraframe modes in order to determine the appropriate mode. This mode determining procedure is undesirably complicated.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a signal compressing system, comprising coding means for scanning an input signal according to a plurality of different scanning patterns to provided coded versions thereof and selection means for selecting a said scanning pattern which produces efficient coding according to a predetermined criterion and outputting a scanning pattern signal identifying the selected scanning pattern.
Preferably, the input signal is an inherently two-dimensional signal, for example, an image signal.
Preferably, the coding means codes the input signal according to a runlength coding regime.
Preferably, the system includes a variable length coder to variably length code the coded signal, produced by scanning according to the selected scanning pattern.
Preferably, the system includes discrete cosine transformer means to produce said input signal. The transformer means may be a motion-compensated interframe adaptive discrete cosine transformer.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the present invention will now be described, by way of example, with reference to FIGS. 2 and 3 of the accompanying drawings, in which:
FIG. 1 is a block diagram of a conventional adaptive interframe DCT coding system employing a motion compensating technique;
FIG. 2 is a block diagram of a coding system embodying the present invention;
FIGS. 3A-3H show various possible scanning patterns according to the present invention; and
FIG. 4 is a block diagram of a decoding system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 2 , an input signal is divided into equal-sized sub-blocks, for example, 8×8, 16×16, . . . A motion estimator 40 determines a motion vector by comparing the current frame and a one frame delayed signal from a frame memory 30 .
The motion vector is supplied to a motion compensator 60 which, in turn, compensates the delayed frame signal for movement. A first adder 8 a produces a difference signal representing the difference between the present frame and the delayed, motion-compensated frame. A DCT coder 10 DCT-codes the difference signal. The DCT coded image signal is quantized by a quantizer 20 and then dequantized by a dequantizer 21 . The dequantized signal is supplied to a second adder 8 b , via IDCT 11 , which adds it to the output of the motion compensator 11 . This produces a signal corresponding to the original image signal.
The output of the motion compensator 50 is applied to the adders 8 a , 8 b by refresh switches RSW 2 and RSW 1 , respectively.
The quantized image signal is also supplied to a multi-scanner 80 which scans it according to a plurality of predetermined patterns.
A scanner pattern selector 90 selects the scanning pattern which produces the minimum number of bits to represent the current sub-block. The scanning pattern selector also produces selection data which identifies the selected scanning pattern.
The image signal output by the scanning pattern selector 90 is variable length coded by a variable length coder 60 . The variable length coder 60 compresses the image signal output by the scanning pattern selector 90 . The variable length coder 60 operates such that a large proportion of the data samples are each represented by a small number of bits while a small proportion of the data samples are each represented by a large number of bits.
When a discrete cosine transformed image signal is quantized and runlength coded, the number of “0”s is increased over all, while the number of “0”s decreases as the magnitude of the signal increases. Accordingly, data compression is achieved because “0” can be represented by only a few bits and “255” can be represented by a relatively large number of bits.
Both the variable length coded signal and the selection data are supplied to a multiplexer MUX 1 which multiplexes the variable length coded signal and the selection data, and optionally additional information such as teletext.
Since the variable length coded signal has data words of different lengths, a transfer buffer 70 is employed to temporarily store the multiplexed signal and output it at a constant rate.
The original image signal is reconstructed at a remote station by performing the appropriate inverse scanning of the runlength coded signal in accordance with the multiplexed scanning pattern selection data.
FIG. 4 shows a decoding system at a remote station that receives and extracts the encoded data. In FIG. 4 , demultiplexer 100 receives coded data and, in an operation inverse to that performed at the coding system, extracts the variable length encoded data, the scanning pattern information and the additional information that had been multiplexed together at the coding system. Variable length decoder 110 variable length decodes the variable length encoded data, and scanner 120 receives the variable length decoded data and reconstructs the original sub-block using a scanning pattern indicated by the extracted scanning pattern selection signal. The scanner would necessarily have to select one from a plurality pattern that was available for encoding. Using components having the same margin as dequantizers 21 and IDCT 11 in the encoder system, dequantizer 120 dequantizes the signal output from the scanner 120 , and inverse discrete cosine transformer 140 performs an inverse discrete cosine transform function on the output of dequantizer 130 , to output decoded data.
FIGS. 3A to 3H show possible scanning patterns employed by the multi-scanner 80 . Additional scanning patterns will be apparent to those skilled in the art. However, if the number of patterns becomes too large, the coding efficiency is degraded as the selection data word becomes longer.
As described above, according to the present invention, the quantized image signal is scanned according to various scanning patterns, and then the most efficient pattern is selected.
A suitable measure of efficiency is the number of bits required to runlength code the image signal.
|
A multi-scanner scans a signal according to several different patterns. A scanning pattern selector determines which scanning pattern produced the most efficient coding result, for example, for runlength coding, and outputs a coded signal, coded most efficiently, and a selection signal which identifies the scanning pattern found to be most efficient.
| 7
|
BACKGROUND
[0001] The present disclosure relates to a three-phase solid bowl screw centrifuge, or three-phase decanter having a rotatable drum, a screw arranged in the drum, a solid material discharge located at a first axial end of the drum, and two liquid outlets located at a second axial end of the drum. A first of the liquid outlets is for a lighter liquid phase and a second of the liquid outlets is for a heavier liquid phase. One of the liquid outlets includes a skimmer disk arranged in a skimmer chamber and the other of the liquid outlets is formed as an over flow. The present disclosure also relates to a method for operating or controlling the separating process by a centrifuge as just described.
[0002] With respect to the state of the art, the following documents are relevant: U.S. Pat. No. 3,623,656, International Patent Document WO 03/074 185 A1; German Patent Documents DE 195 00 600 C1, DE 102 23 802 A1, DE 38 22 983 A1; International Patent Document WO 02/062483 A1; and, German Patent Document DE 26 17 692 A1.
[0003] U.S. Pat. No. 3,623,656 shows a three-phase decanter by which two liquid phases and one solid phase can be discharged from the drum. When the machine is stopped, the liquid outlets can be adjusted by a conversion.
[0004] International Patent Document WO 03/074 185 A1 shows a three-phase decanter by which also two liquid phases and one solid phase can be discharged from the drum. The outflow quantity of the heavier liquid phase can be adjusted by a weir.
[0005] German Patent Document DE 38 22 983 A1 illustrates a three-phase decanter by which also two liquid phases and one solid phase can be discharged from the drum, one liquid phase being discharged through a weir and the other being discharged through a skimmer disk.
[0006] German Patent Documents DE 195 00 600 C1 and DE 102 23 802 A1 indicate two-phase decanters where the liquid is discharged by a skimmer disk, or centripetal, from a chamber.
[0007] International Patent Document WO 02/062483 A1 shows a method of operating a solid bowl screw centrifuge.
[0008] German Patent Document DE 26 17 692 A1 discloses a solid bowl screw centrifuge having several disk stacks consisting of separating disks and several screw areas.
[0009] In the case of three-phase separating decanters, as a rule, conversion parts are available for the adaptation to the respective product characteristics or for the adaptation of the process to the respective situations.
[0010] If, for example, during the process of obtaining olive oil in a three-phase operation, the product characteristics of the olive change from the start to the end of the harvest, it may be necessary to stop the processing, to remove the rotor and to install other regulating disks and/or regulating tubes. This is time-consuming and cost-intensive.
[0011] It has been suggested to regulate the heavier phase by a non-rotating throttle disk arranged outside the drum and to discharge the lighter phase by a skimmer disk, or centripetal pump. Although this construction has been successful, it requires at least the use of a displaceable throttle disk from a constructive point of view.
[0012] However, by varying the throttling at the skimmer disk, or centripetal pump, alone, the process cannot be sufficiently adjusted to the product characteristics, in order to avoid a conversion.
[0013] With respect to the above, the present disclosure relates to reducing the constructive expenditures for creating a three-phase decanter that is easily adaptable to changing product characteristics and of indicating an advantageous method for its operation.
[0014] The present disclosure relates to a three-phase solid bowl screw centrifuge comprised as follows.
[0015] A rotatable drum, a screw arranged in the drum, a solid material discharge located at a first axial end of the drum, and two liquid outlets located at a second axial end of the drum. A first of the liquid outlets is for a lighter liquid phase and a second of the liquid outlets is for a heavier liquid phase. One of the liquid outlets includes a skimmer disk arranged in a skimmer chamber and the other of the liquid outlets is formed as an overflow. Two regulating disks are located in front of the skimmer disk and extend radially from an outside of the drum toward an inside of the drum. A siphon disk extends between the regulating disks and into the skimmer chamber from an interior circumference of the skimmer chamber to an exterior circumference of the skimmer chamber. An annular chamber is formed during an operation and is located between the siphon disk and the skimmer disk. The siphon disk and skimmer disk act as axial boundaries for an axial area, and the annular chamber is further located between an inside radius of the lighter liquid phase in the axial area and an inner wall of the skimmer chamber in the axial area. A fluid feed pipe leads into the annular chamber to change a pressure on the annular chamber and to change at least one of a separation zone between the lighter and heavier phases and/or a pool depth in the drum. A feed pipe and a removal pipe for feeding fluid to the chamber and removing it from the chamber may also be provided.
[0016] As a result of a change of pressure in the annular chamber, as required, in connection with a throttling effect onto the skimmer disk, or centripetal pump, the separating zone in the drum can easily be shifted, which also results in a change of the liquid level. A conversion, which would otherwise be required as a result of changes of the characteristics of the product, as a rule, can be eliminated by utilizing the given regulating range. The constructive expenditures for providing the annular chamber are low.
[0017] As suggested above, the annular chamber, preferably, has a fluid pipe for feeding a fluid, particularly a gas, into the annular chamber, as a device for changing the pressure in the annular chamber.
[0018] The overflow for the other phase can be implemented by radial discharge pipes, which penetrate the drum shell or the drum lid.
[0019] This basic construction can be implemented particularly in two variants. In one variant, the heavier liquid phase is discharged through the discharge pipe and the lighter liquid phase is discharged through the skimmer disk, or centripetal pump. In the other variant, the lighter liquid phase is discharged through the discharge pipe and the heavier liquid phase is discharged through the skimmer disk. Both variants permit a good controlling of the process but result in different regulating characteristics.
[0020] The present disclosure also relates to a process for operating a three-phase solid bowl screw centrifuge. The regulating of the separating operation in the drum takes place in a very simple manner by changing the pressure in the annular chamber as the manipulated variable. This variant may be preferred because a simple and good regulating of the separating operation becomes possible.
[0021] As an alternative, it is also conceivable that the regulating of the separating operation in the drum takes place by changing the rotational speed of the drum as the manipulated variable.
[0022] The regulating of the separating operation in the drum may also take place as a function of the concentration in the solid phase or in one or both discharged liquid phases as the controlled variable.
[0023] The embodiments of the present disclosure are also suitable for the phase separation when obtaining hydrometals, such as cobalt, nickel, copper.
[0024] When obtaining hydrometals, such as cobalt, nickel, copper, the emulsion formation cannot be avoided during the extraction. The extraction, as well as the emulsion, includes three phases: an organic phase; an aqueous phase; and a solids phase. The open sedimentation tanks of the extraction are susceptible to contamination from the air. These different dust concentrations lead to a density difference of the individual phases in the emulsion. The decanter, according to the present disclosure, provides a remedy.
[0025] In order to meet these dynamic process demands, the separating diameter within the decanter can be adapted on-line by an increase of pressure into the annular chamber. As a result, the emulsion is cleanly separated into three phases. The use of a centrifuge according to the present disclosure for the emulsion separation when obtaining hydrometals, such as cobalt, nickel, copper, therefore offers considerable advantages.
[0026] Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a sectional view of a first embodiment of a three-phase solid bowl screw centrifuge, according to the present disclosure.
[0028] FIG. 2 is a schematic sectional view of a partial area of the solid bowl centrifuge of FIG. 1 in a first operating condition.
[0029] FIG. 3 is a schematic sectional view of a partial area of the solid bowl centrifuge of FIG. 1 in a second operating condition.
[0030] FIG. 4 is a diagram illustrating the operating behavior and the controllability of separating and clarifying processes by the solid bowl centrifuge of FIG. 1 , according to the present disclosure.
[0031] FIG. 5 is a sectional view of a second embodiment of a three-phase solid bowl screw centrifuge, according to the present disclosure.
[0032] FIG. 6 is a schematic sectional view of a partial area of the solid bowl centrifuge of FIG. 5 in a first operating condition.
[0033] FIG. 7 is a schematic sectional view of a partial area of the solid bowl centrifuge of FIG. 5 in a second operating condition.
[0034] FIG. 8 is a diagram illustrating the operating behavior and the controllability of separating and clarifying processes by the solid bowl centrifuge of FIG. 5 , according to the present disclosure.
DETAILED DESCRIPTION
[0035] FIGS. 1 and 5 illustrate parts of first and second embodiments of three-phase solid bowl screw centrifuges, according to the present disclosure, which have a rotatably disposed drum 1 , for example, on bearings 17 . Drum 1 has a horizontal axis of rotation and a rotatable screw 2 which is arranged in the drum 1 . Screw 2 has a screw body 3 on which a circulating screw blade 4 is arranged. During an operation, the drum 1 and the screw 2 rotate at different rotational speeds n, m, respectively, about the same axis of rotation, as seen at diameter D 0 in FIG. 1 . A bearing 16 is arranged between the drum 1 and the screw body 3 . A second bearing of the screw 2 is situated on a solids discharge side (not shown).
[0036] Drum 1 as well as the screw 2 tapers at one of its ends, for example, conically. At the tapering end of the drum 1 , a solids discharge 24 is arranged for a solid phase S transported to this end of the drum 1 by the screw 2 . Two liquid phases, LL and HL, a lighter and a heavier density of a liquid phase, respectively, which can be mutually separated in a centrifugal field, are discharged from the drum 1 in an area of an opposite cylindrical end of the drum 1 , which is closed by a drum lid 5 .
[0037] For example, in a transition area to the tapering section, a baffle plate 18 can be arranged on the screw body 3 .
[0038] Further, for example, an inlet pipe 19 extends from the cylindrical end of the drum 1 into the drum 1 . This inlet pipe 19 leads into a distributing device 20 by way of which a product is guided into the drum 1 .
[0039] The drum lid 5 has several breakthroughs or openings 21 , 22 axially penetrating the drum lid 5 . Preferably between four and eight such openings are formed on a circle of a defined diameter in the drum lid 5 and are distributed along the circumference.
[0040] Some of these openings, for example, first openings 21 , are constructed in the form of recesses closed on one side, or, formed in the manner of pocket holes, and are used for discharging the heavier liquid phase HL. Other openings, for example, second openings 22 . are used for discharging the lighter liquid phase LL.
[0041] For an implementation, a separating-plate-like separating weir 6 is disposed in front of some of the openings, for example, the first openings 21 . The separating weir 6 is further developed and arranged such that only the heavy phase HL is discharged by way of an outer radius of this separating weir 6 in all provided operating conditions. In contrast, the second openings 22 have no such separating weir 6 .
[0042] To this extent, the constructions of the embodiments of FIGS. 1 and 5 are essentially identical.
[0043] However, a difference between the embodiments of FIGS. 1 and 5 is that areas of the drum or decanter 1 arranged behind the first and the second openings 21 , 22 , 25 , 26 are quasi “exchanged” in relation to the separating weir 6 which is situated in front of the openings leading to the centripetal pump, or skimmer disk 9 .
[0044] This difference will be explained later herein.
[0045] According to FIG. 1 , the heavier liquid phase HL, collecting radially farther to an outside of the drum 1 , is guided by way of the separating weir 6 on the drum lid 5 into a discharge space 7 adjoining the separating weir 6 along a portion of a circumference of the separating weir 6 . The discharge space 7 is formed by the openings 21 themselves. Discharge pipes 8 , penetrating a drum shell, project into the discharge spaces 7 . An inner radius, to which the respective discharge pipe 8 extends, also determines a discharge radius for the heavier liquid phase HL.
[0046] During the operation or during a running process, this discharge radius for the heavier phase HL is not variable. It can be changed or pre-adjusted when the drum 1 is stopped by exchanging the discharge pipe 8 or small tube for one of a different length.
[0047] In contrast, the discharge of the lighter liquid phase LL, after the passage through the second openings 22 , takes place by centripetal pump, or skimmer disk 9 . Skimmer disk 9 which is arranged in a skimmer chamber 10 , or centripetal chamber, connected in front of the drum shell. The skimmer chamber 10 axially adjoins a drum interior and its inside diameter is equal to or, preferably, smaller than the inside diameter of the drum 1 in its cylindrical area. The light liquid phase LL is discharged from the drum through skimmer disk 9 and a discharge duct 23 adjoining this skimmer disk 9 .
[0048] Toward the drum interior, see FIGS. 2 and 3 , in the skimmer chamber 10 , two regulating disks 11 , 12 , which may be of the same inside diameter are disposed in front of the skimmer disk 9 . The regulating disks 11 , 12 extend radially from an outside of the drum 1 toward an inside of the drum 1 . A siphon disk 13 dips between these two regulating disks 11 , 12 and extends in the skimmer chamber 10 from its inner circumference to the outside. The outside diameter of the siphon disk 13 is situated on a larger radius relative to the axis of rotation, at D o , of the drum 1 than an inside diameter of the two regulating disks 11 , 12 .
[0049] The regulating disk 11 facing the separating weir 6 defines an overflow diameter for the light liquid phase LL.
[0050] An annular chamber 14 is formed during an operation and is located between the siphon disk 13 and the skimmer disk 9 , which form axial boundaries for an axial area, and the annular chamber 14 is further located between an inner radius of the lighter liquid phase LL in this axial area and an inner shell or inner wall of the skimmer chamber 10 in this axial area.
[0051] A fluid feeding pipe 15 , through which a fluid, such as a gas, can be guided from the outside of the drum 1 into the annular chamber 14 , leads into this annular chamber 14 .
[0052] In this manner, it becomes possible to change the pressure in the annular chamber 14 , which also causes a change of the radius of the lighter liquid phase LL and thus has an effect on a separating diameter D_separate in the drum 1 . It thereby becomes easily possible to influence two quantities: a pool depth, which is an inside radius of the drum 1 minus a radius at a line D_level position, for example, see FIG. 3 ; and, a separating zone Z between the lighter liquid phase LL and the heavier liquid phase HL. This is possible during the operation only by influencing or changing the pressure in the annular chamber 14 .
[0053] As a result of the selection of the diameter of the regulating disks 11 , 12 or their exchange, the overflow diameter of the lighter phase LL can be pre-adjusted.
[0054] When the pressure in the annular chamber 14 is increased, the liquid level to the center, or pool depth, rises in the interior of the drum 1 . Analogously, a diameter of the separating zone Z is displaced farther toward the outside, for example, compare FIGS. 2 and 3 .
[0055] As a result, a layer thickness of the lighter phase LL, for example, a broken vertical line, becomes greater and the flow-off velocity becomes lower, that is, a longer sedimentation time. The degree of clarification of the lighter phase LL is thereby increased or becomes better.
[0056] Since the separating zone Z moves toward the outside, the degree of clarification of the heavier phase HL, for example, a horizontal broken line, has the tendency to become poorer. The crosswise hatching indicates a mixed phase area or a separating zone Z area.
[0057] For the most part, the outflow pressure of the lighter phase LL, i.e., the skimmer disk 9 pressure can be varied independently of the chamber pressure.
[0058] When, for example, a concentration of the heavy phase HL, or mixed phase, increases, the pressure in the annular chamber 14 rises in order to shift the separating zone Z in the drum interior farther toward the outside to a greater radius. As a rule, this causes a greater layer thickness and a better degree of clarification of the lighter phase LL or a better phase separation.
[0059] The above-described behavior tendency is shown in the diagram of FIG. 4 .
[0060] The diagram of FIG. 4 shows the diameters of the outflow for the light and the heavy liquid phases LL, HL, respectively. It also shows the D_level position in the drum 1 , and the separating diameter D_separate, as a function of the pressure in the annular chamber 14 .
[0061] The diagram of FIG. 4 shows the behavior at a constant rotational speed.
[0062] Because of the change of pressure, the liquid filling in the drum 1 is not constant. In each case, D indicates the diameter in the drum on both sides of the axis of rotation. Diameter D_pipes, that is, diameter discharge pipes and D_separating weir are each kept constant during the operation, although they are variable, for example, by an exchange. The inside diameter of the drum and the inside diameter of the solids discharge, as a rule, are also not variable by a conversion. The diameter on which the separating zone Z is situated, i.e., the separating diameter, increases with the pressure. In contrast, the liquid level D_level position falls inversely proportionally to the pressure.
[0063] FIGS. 2 and 3 schematically illustrate the conditions in the drum 1 at different pressures.
[0064] It is also conceivable to fixedly define a pressure in the annular chamber 14 during the operation and then achieve a change of the separating diameter D_separate in the drum 1 only by changing the rotational drum speed. This change of the rotational speed can take place, for example, as a function of a concentration measurement of the product inflow or outflow.
[0065] However, in the case of this type of control, the regulating range is smaller and can also only be used if a changing of the rotational drum speed during the operation is permissible. The diameter of the separating zone D_separate will then increase with the rotational speed (not shown).
[0066] FIG. 5 illustrates the second embodiment, according to the present disclosure. Here, the heavier liquid phase HL is discharged by way of the regulating disk arrangement, i.e., disks 12 , 13 and the skimmer disk 9 . The lighter liquid phase LL is discharged by way of the discharge pipe 8 , which is achieved in that there the separating-plate-like separating weir 6 is arranged in front of the continuous two openings 26 which are open on both sides. The separating weir 6 thereby guides the heavy liquid phase HL to the skimmer disk 9 , whereas the lighter phase LL is discharged by way of the discharge pipes 8 in the first openings 25 , which are of a pocket hole type or are closed at one end.
[0067] In the annular chamber 14 , the pressure thereby acts upon the heavier liquid phase HL.
[0068] When the pressure in the annular chamber 14 is increased in the embodiment of FIG. 5 , on the drum side of the siphon disk 13 , the inside diameter of the heavier phase HL shifts to the center, and the separating zone diameter shifts farther toward the interior or is reduced. This has the result that the layer thickness of the lighter phase LL becomes smaller and that the outflow velocity is increased. The degree of clarification of the lighter phase LL is thereby reduced. FIG. 6 shows the higher-pressure condition, and FIG. 7 shows the condition after a lowering of pressure in the annular chamber 14 .
[0069] Since the separating zone Z moves farther toward the inside, in contrast, the degree of clarification of the heavier phase HL becomes better.
[0070] The concentration distribution of any of the discharged phases, for example, is preferably used as the controlled variable.
[0071] When, for example, the pressure of the heavy liquid phase HL rises in the light liquid phase LL, the pressure is reduced in order to shift the separating zone Z in the drum interior farther toward the outside to a larger radius. As a rule, this causes a larger layer thickness and a better degree of clarification of the lighter phase LL.
[0072] FIG. 8 illustrates the corresponding control behavior by an example analogous to FIG. 4 . The different diameters are again entered as a function of the pressure in the annular chamber 14 .
[0073] Here, it is also conceivable to fixedly define a pressure in the annular chamber 14 during the operation and to achieve a change of the separating diameter in the drum I solely by changing the rotational speed of the drum 1 . This change of the rotational speed can take place, for example, as a function of a concentration measurement of the product inflow or outflow.
[0074] However, in the case of this type of the control, the control range is smaller and can also be used only when a changing of the rotational drum speed during the operation is permitted.
[0075] Although the present disclosure has been described and illustrated in detail, it is to be clearly understood that this is done by way of illustration and example only and is not to be taken by way of limitation. The scope of the present disclosure is to be limited only by the terms of the appended claims.
|
A three-phase solid bowl screw centrifuge has a rotatable drum ( 1 ) and a screw ( 2 ) arranged in the drum ( 1 ). In this case, at least one solid material discharge is arranged at one axial end of the drum ( 1 ) and at least two or more liquid outlets for liquid phases of different densities—a lighter liquid phase and a heavier liquid phase—are arranged at its other axial end. The one liquid outlet also has a skimmer disc and the other liquid outlet is formed as an overflow weir, the skimmer disc being preceded by two regulating discs ( 11, 12 ) of the same inside diameter, which extend radially from the outside inwards and between which there enters a siphon disc ( 13 ), which in the skimming chamber ( 10 ) extends from the inner circumference of the latter outwards. This has the effect of forming an annular chamber ( 14 ), which is assigned a means for changing the pressure in the annular chamber ( 14 ).
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
A hydralically operated clutch modulator for modulating the rate of engagement of a hydraulic clutch is provided.
2. Description of the Prior Art
Numerous prior art patents exist that attempt to provide clutch engagement modulation. There are patents, such as U.S. Pat. No. 3,351,170 to E. Hengstler, which show hydraulic clutch packs downstream of a modulating valve interposed between the clutches and a hydraulic fluid supply pump have been investigated and found operatively different when compared to the instant invention.
Prior art devices are also known where pressure is provided behind a poppet valve equivalent to pressure provided to the clutch packs until the clutch packs are fully pressurized. When fully pressurized the poppet valve also closes preventing further pressure buildup in the clutch packs. This is a rather typical embodiment but it does not allow for flow past the modulator valve (or the poppet valve) to the torque converter as does the instant invention.
BRIEF SUMMARY OF THE INVENTION
A clutch modulator valve for use in a vehicle equipped with a torque converter transmission engageable through a hydraulic clutch pack incorporates a direction selector spool valve for selectively directing fluid flow from a source of fluid pressure to one of either a forward or reverse clutch pack in order to lock up the hydraulic clutch of a vehicle in a smooth, rapid manner. A first area of a modulator valve spool is subjected to pump pressure at all times while a second area is exposed to forward clutch pack feed line pressure as the selector spool is moved to a forward position. A third modulator valve spool area is subjected to a reverse clutch pack feed line pressure when the selector spool valve is moved to a reverse direction position. The modulator valve spool continuously cycles from a closed position to an open position at a very rapid rate responsive to pressure differentials between the first area and alternatively the second or third areas. A spring in cooperation with fluid pressure urges the modulator valve spool to a closed position while the fluid pressure seen by the first area urges the modulator valve spool off its seat. Metered fluid flow is directed to the second area or alternatively to the third area whereas fluid to the first area is unencumbered.
A dump valve is provided that allows the clutch pack fluid lines to go to dump without interrupting fluid flow through the modulator valve from the pump to the torque converter.
Also provided in this cluth modulator valve is a regulator valve for regulating the downstream system pressure between the clutch modulator and the torque converter.
In the clutch modulator herein described the object is to provide a device that will control the lock up rate of a hydraulic clutch while permitting the passage of fluid to a downstream torque converter.
Also advantageous is to provide, in the same clutch modulator, potential for rapidly energizing alternatively a forward and a reverse clutch to provide rapid reversals in vehicle direction with minimum operator effort. Harsh clutch engagement can be tempered in prior art devices by modulating or accurately controlling the pressure rise in the appropriate clutch pack, however, this fine control is subject to operator error and occupies a substantial amount of time causing inefficient tractor operation.
A further significant advantage and object of this invention is to provide a clutch modulator with a dump valve that can dump both the forward and reverse clutch pack pressure heads without interrupting fluid flow from the pump to the torque converter even though the clutch modulator is interposed therebetween.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of the modulator valve assembly;
FIG. 2 is a cross sectional view through plane 2--2 of FIG. 1;
FIG. 3A is a cross sectional view through plane 3--3 of FIG. 1;
FIG. 3B is an enlarged view of a portion of FIG. 3A;
FIG. 4 represents a circuit incorporating one modulator valve assembly sectioned to correspond to FIGS. 2 and 3.
DETAILED DESCRIPTION OF THE INVENTION
The modulator valve assembly, generally 10 in FIG. 1 includes a modulator valve body 12, a fluid supply port 14 which may receive fluid from a hydraulic pump 16 of an appropriate type. A dump valve spool 20 protrudes from the modulator valve body. A first external conduit 22 shown in a broken line representation allows fluid communication from forward modulator fluid source port 24 to forward modulator control port 26. A second external conduit 30 allows fluid communication between a reverse modulator fluid source port 32 and a reverse modulator control port 34. First and second flow restrictions 36 and 40, allowing restricted passage of fluid in one direction and uninterrupted fluid passage in a second direction, are interposed in first and second external conduits 22 and 30 respectively.
Examination of FIGS. 1, 2 and 3 together will yield a clear understanding of the passages and spools in the modulator valve assembly. The modulator valve body 12 in FIG. 2 shows clearly a direction selector spool 38 comprising a shaft 42 having three lands 44, 46, and 50 for controlling fluid flow through the modulator valve assembly. One end of the shaft 42 is equipped with a detent portion 52 comprising three detent grooves which may be engaged by a pair of spring biased detent ball devices 54 and 56. A retainer 60 is threaded into the shaft 42 to position a limiting flange 62 which may limit the travel of the shaft in the selector valve bore 64 by contacting the decreased bore diameter ledge.
The dump valve spool 20 is slideably carried in dump valve bore 70. This spool is provided with a decreased diameter portion 72 through which a first radial passage 74 is formed. A second radial passage 76 is formed in the lower portion of the dump valve spool and is connected to the first radial passage by a longitudinal passage 80. In an undumped position as is shown in FIG. 2 fluid entering the internal passages of the dump valve spool 20 is prevented from passing therethrough as the openings of the second radial passage are blocked by the walls of the bore 70.
Both the dump valve spool 20 and the direction selector spool 38 are equipped with apertures at their upper ends for accommodating control linkages which are not shown but would be conventional.
The fluid passages shown in FIG. 2 include the supply port passage 82. This supply port passage feeds a distribution passage 84 which passes around the decreased diameter portion 72 of the dump valve spool 20 and continues into the bore 64 of the direction selector spool 38 between first 44 and second 46 lands thereof.
Item 86 is a plug.
A forward clutch supply passage 90 connects a forward clutch supply port 92 to a forward modulator fluid source port 24. A reverse clutch supply passage 96 connects a reverse clutch supply port 100 to a reverse modulator fluid source port 32.
A first drain passage 104 and a second drain passage 106 are provided. The second drain passage 106 may receive fluid through the dump valve spool 20 when it is displaced in its bore 70 such that second radial passage 76 is uncovered.
FIG. 3 is a section view through plane 3--3 of FIG. 1 showing operational equipment. The modulator valve body 12 is provided with a modulator spool bore 110 for receiving a modulator spool 112 slideably therein. A modulator spool guide 114 having an aperture 116 is maintained in axial alignment in the modulator spool bore 110 by an apertured end cap 120. A snap ring 122 is maintained in a groove in the modulator spool guide. A spring 124 urges the modulator spool 112 against seat 126.
The aligned apertures of the end cap 120 and the modulator spool guide 114 correspond to the forward modulator control port 26. The reverse modulator control port 34 communicates with the modulator spool bore 110.
Supply port passage 82 is continuous to a torque converter supply port 130 when the modulator spool 112 is off seat 126.
A regulator poppet 132 carried in a poppet bore 134 is urged by poppet spring 136 against seat 140. Orifice 142 opens into cavity 144 which is also occupied by movable dampening pin 146. The regulator poppet controls fluid pressure on the torque converter side of the modulator spool by acting responsive to pressure in regulator passage 150. When the regulator poppet 132 is unseated fluid may flow to reservoir 152 via passage 154.
The operation of the modulator valve assembly can best be understood through a perusal of FIG. 4. In this figure the clutch modulator assembly is divided into two cross sectional pieces corresponding to the FIG. 2 and 3 section views. This is done so that the operation of the valve can be easily envisioned. The valve assembly of course is only a single body as shown in the first three figures. Components shown include a forward clutch pack 156 and a reverse clutch pack 160 of conventional design including a plurality of friction discs and a piston operating in a cylinder that when pressurized locks up the clutch discs. Forward and reverse, 162 and 164, clutch pack supply lines are connected respectively to ports 92 and 100. First drain line 166 and second drain line 168 allow the first and second drain passages 104 and 106 to pass to the reservoir 152.
Hydraulic pump 16 supplies fluid to supply port passage 82 via conduit 170.
As stated earlier external conduit 22, including first flow restriction 36 provides communication between the forward modulator fluid source port 24 and the forward modulator control port 26. Likewise external conduit 30, including restriction 40, allows communication between the reverse modulator fluid source port 32 and the reverse modulator control port 34.
The torque converter 172 receives fluid from the torque converter supply port 130 via conduit 174. Passage 154 from the regulator poppet portion of the clutch modulator assembly drains to tank 152 via conduit 176.
OPERATION
With the direction selector spool 38 in a neutral position as shown hydraulic fluid from the pump 16 flows to the torque converter 172 past the unseated modulator spool. The torque converter is always provided with fluid from the pump. The pressure will be limited by the regulator poppet 132 to a preset maximum torque converter system pressure. Excess pressure will be relieved by the regulator poppet and directed to the reservoir 152.
When the direction selector spool 38 is indexed to the forward position (upwardly in the selector valve bore 64) access to the first drain passage 104 is blocked and fluid from the pump will fill the forward clutch pack 156 and at the same time flow through external conduit 22 from fluid source port 24 to control port 26. As fluid fills the forward clutch pack the modulator spool 112 is urged towards its seat 126 creating a pressure drop from supply port passage 82 (chamber A) to the torque converter supply port 130 (chamber B). This increase in chamber A pressure results in a corresponding increase in forward clutch pack pressure and modulator spool pressure due to pressure acting on area 180 of the modulator spool 172. Since the modulator spool has more pressure urging it to close due to the combined forces of pressure on area 180 and the added force supplied by spring 124, than it does to open based on pressure on area 182, it generates an even greater pressure drop from chamber A to chamber B. This regulating will continue until full pressure is realized at the clutch and a balance is reached at the modulator spool. The modulator spool 112 will be balanced to a point that allows fluid flow from the pump 16 to the torque converter 172 to be uninterrupted. This is possible as the modulator spool nose is tapered to present a varying surface area 182, as constrained by the seat 126.
The shape of the modulator spool nose is shown in the enlarged auxiliary view of FIG. 3. The seat 126 presents a square corner between the torque converter supply port 130 and the supply port passage 82. The modulator spool nose 182 comprises a relatively flat surface formed with a beveled edge 186 which presents the varying surface area with respect to the seat 126 as the spool moves vertically in the bore as shown.
The combined force of the spring 124 and pressure on area 180 exceeds the area 182 when the modulator spool is unseated thus urging the modulator spool towards its seat. However, the pressure on area 182 increases due to the pressure drop generated by the tapered nose profile of the modulator spool as it approaches its seat 126 until the force seen by area 182 is equal to the combined spring and hydraulic forces. The modulator spool will continually vacilate between various degrees of openness thus allowing fluid passage to the torque converter.
This adjusting of the modulator spool controls the buildup of pressure in the clutch pack allowing very rapid engagement without a harsh, instantaneous grabbing of the clutch.
To change direction from forward to reverse the reverse clutch pack needs to be engaged immediately after pressure locking up the forward clutch pack is relieved. The direction selector spool 38 is moved downwardly in its bore to the reverse position. The forward clutch pack 156, is drained to the reservoir 152 via fluid conduits 162, 92, 104, 166 as is the modulator spool from area 180 through 26, 36 (the unrestricted check valve side thereof), 22, 24, 104, 166. The pressure is relieved in the forward clutch pack before pressure buildup is initiated in the reverse clutch pack. This is accomplished through the placement of lands 44 and 46 on the direction selector spool 38 relative to forward and reverse clutch supply passages 92 and 100 respectively. It can be seen by looking at the drawing FIGS. 2 and 4 that as the direction selector spool 38 is moved from forward to reverse it passes through neutral where, supply port 92 communicates directly with first drain passage 104 while the fluid supply through the distributor passage 192 is blocked. This is necessary to prevent accidental pressure buildup in both clutch packs at the same time which may be deleterious to the vehicle drive line.
Of course the same protection is provided when going from reverse to forward due to the placement of the direction selector spool lands. The rise rate of the reverse clutch pack 160 pressure is controlled in the same manner as the rise rate of the forward clutch pack as explained above. Specifically second drain passage 106 is blocked by second land 46 and fluid from the pump 16 will fill the reverse clutch pack 160 and at the same time flow to the reverse modulator control port 34 through external conduit 30. As fluid fills the reverse clutch pack the modulator spool 112, due to fluid pressure acting on annular area 184 and the force of the spring, is urged toward its seat 126 creating a pressure drop from supply port passage 82 (chamber A) to the torque converter supply port 130 (chamber B). This increase in chamber A pressure results in a corresponding increase in reverse clutch pack pressure and modulator spool pressure due to the pressure acting on annular area 184 of the modulator spool 172. Once this modulating action is initiated the activity of the modulator spool here controlling the reverse clutch pack engagement, will proceed as set forth above in the description of the forward clutch pack engagement.
The dump valve spool 20, which operates as a clutch pressure unloading valve has been incorporated into the modulator valve assembly. This dump valve spool allows fluid to be drained from an engaged clutch pack through second drain passage 106 via second drain line 168 to reservoir 152 without allowing fluid from the pump to go directly to the reservoir and thus detrimentally interrupting the flow to the torque converter during an emergency stop. The dump valve lands, an upper being 186 and a lower being 190, are so spaced relative to lands of the bore 70 as to first close off communication from supply port passage 82 to distributor passage 192 then open communication between the engaged clutch pack and the reservoir. This ensures uninterrupted pump flow to the torque converter.
The operation of the regulator poppet 132 is relatively straight forward. It will be unseated when fluid pressure in chamber B exceeds torque converter capacity. When unseated, fluid will flow directly to the reservoir 152 via conduit 176. The regulator poppet action is dampened by the dampening system comprised of the movable dampening pin 146 operating in cavity or bore 144 which is opened via orifice 142 to chamber B pressure. Before the poppet is unseated the dampening pin 146 will be partially displaced outwardly from bore 144 until it reaches the extreme of its travel. This will be followed by the unseating of the poppet 132 which will be resisted by the poppet spring 136 force and dampened by the restricted flow of fluid outward from bore 144 through orifice 142 as the dampening pin is moved inwardly through the bore 144 displacing fluid therefrom. When the regulator poppet is re-seated the dampening pin will generally remain at the extreme of its travel maximizing the volume capacity of the cavity or bore 144 as even nominal fluid pressure in cavity B will urge the pin outwardly of the bore.
A typical instance where the regulator poppet will be unseated would be when full pump pressure and flow is being delivered to chamber B as the drive selector spool is held in neutral or moved from forward to reverse through neutral. The option of the pump 16 being a variable displacement pump or a fixed displacement pump will of course be determined of the amount of time the regulator spool is unseated allowing excess fluid pressure to go to dump.
Thus it has been shown that there has been provided a clutch modulator displaying all the advantages and objects as set forth above. While the invention has been described in conjunction with specific embodiments thereof it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.
|
Modulated hydraulic clutch pack engagement is provided in a single valve body which includes a drive direction selector spool, a dump valve, a pressure modulating spool, a downstream system pressure regulator and a provision for continuous flow to a downstream torque converter. The modulator spool interrupts communication between a first and second chamber. Fluid pressure develops in the first chamber in response to selector spool initiation of clutch pack fill line pressure. A pressure differential is generated between the first and second chambers resulting in modulator spool displacement allowing equalization of chamber pressures. Metered flow to the back side of the modulator spool generates pressure that reseats the spool with the aid of spring pressure. Pressure then builds in the first chamber. The modulation is repeated rapidly resulting in the clutch pack being fully pressurized, however, the modulator will continue to regulate fluid to be supplied to the torque converter.
The dump pedal allows dumping of the pressurized clutch pack without interrupting flow between the supply pump and the torque converter.
| 5
|
FIELD OF THE INVENTION
The present invention relates to a method for matching of a repair paint to texture properties, and optionally colour, of a paint film on a substrate to be repaired.
BACKGROUND OF THE INVENTION
Repairing painted surfaces requires that the repair paint visually matches the originally applied paint film. To this end, the colour of the original paint film is measured and subsequently a paint composition is determined having substantially the same colour within a predetermined tolerance. This can be done by searching a suitable paint composition in a databank or a suitable paint composition can be calculated based on the colorimetric data of the paint components.
To allow easy formulation of matching paints in any colour, toners are often used. Toners are compositions of base colours comprising all ingredients which make up a complete paint. These toners can be mixed to obtain a paint of a colour, which after being applied and dried as a paint film, matches the colour of the paint originally coating the substrate. Based on the colorimetric data of the individual toners, the colorimetric features of mixtures can be predicted by calculation, taking into account the concentrations of the toners used. Alternatively, paint compositions can be formulated on basis of other types of modules, such as pigment concentrates, binder modules, effect modules, components comprising flop-controllers, etc.
Besides colour, a paint film shows numerous further visual properties. Particularly when effect pigments, such as for example aluminum flake pigments or pearlescent pigments, are used, the look of a paint film is not of a uniform colour, but shows texture. This can include phenomena as coarseness, glints, micro-brilliance, cloudiness, mottle, speckle, sparkle or glitter. In the following, texture is defined as the visible surface structure in the plane of the paint film depending on the size and organization of small constituent parts of a material. In this context, texture does not include roughness of the paint film but only the visual irregularities in the plane of the paint film. Structures smaller than the resolution of the human eye, contribute to “colour”, whereas larger structures generally also contribute to “texture”.
Also particles which are not directly observable by themselves, can contribute to the overall visual appearance of a paint film. Des-orienters are an example of such particles. Effect pigments are generally flakes tending to take a horizontal orientation in a cured film. To prevent this, and to obtain more variation in flake orientation, spherical particles are used, referred to as des-orienters. Using des-orienters in a metallic paint, results in more glitter.
Hitherto, the texture of the paint film to be repaired was judged by the eye, e.g., by comparing it with samples on a sample fan. The results of such approach are strongly dependent on the skills of the practitioner and are often not satisfying.
In practice, a colour specialist wanting to match a textured paint, first selects one or more effect modules or toners to obtain a matching texture effect. Meanwhile or subsequently, colourant modules or toners are selected to obtain a colour match. The result is compared with the original paint and iteratively adjusted if correction appears to be necessary. Selecting the right effect modules is difficult and requires a trial and error approach or accurate computer analysis of the effect pigments in the paint to be matched.
EP-A 637 731 discloses a method for reproducing texture properties of a paint film. The reproduced paint is formulated on basis of concentrations of paint modules. The formulation is selected from a database or formulations with given texture properties. If this does not result in a satisfying match, corrections can be made by interpolation between two close matches.
WO 01/25737 discloses a method of combined colour and texture matching, using a digital imaging device, such as a CCD camera, to determine the texture.
A matching paint is determined by searching in a databank of colour formulations linked to texture data.
US 2001/0036309 discloses a method of measuring micro-brilliance and using it for matching a repair paint with an original paint on, e.g., an automobile. The method includes measurement of colour as well as micro-brilliance, a specific type of texture. A colour formula with a matching micro-brilliance is selected from a databank of paint formulas. Consequently, the obtained micro-brilliance texture is acceptably matching. However, the colour is not necessarily matching evenly well. Hence, the colour formula needs to be iteratively adjusted until the colour match is also acceptable. In this prior art system, colour formulas that initially do not have the right texture are not taken into consideration, although these formulas could still be viable candidates as a formulation to start with. Furthermore, this prior art method does not assure that the texture remains intact during the adjustments of the colour formulas.
SUMMARY OF THE INVENTION
The object of the invention is to improve matching of repair paints with paint originally applied on a substrate to give more accurate results in a faster and more reliable way, preferably without the need to build up a database of complete formulations with specified texture data.
The object of the invention is achieved by a method for matching a repair paint to texture properties of a paint film on a substrate to be repaired, the repair paint being formulated on basis of concentrations of paint modules characterized in that each paint module is associated to specified texture data, and in that a calculational texture model using the texture date of the paint modules to calculate a repair paint with matching texture properties.
These texture data can for instance include the particle size distribution of the effect pigments in the toner, and the optical contrast, defined as the difference in lightness, between the effect pigment and the other toner pigments present in the toner.
Surprisingly it was found that a matching texture can be obtained by mixing toners selected from a limited range of toners showing particular pre-determined texture parameters, and that a computer can be used to calculate a matching mixture of texture toners.
Preferably, the paint is also matched with the colour properties of the original paint. It has unexpectedly been found that by simultaneously matching colour and texture, the overall visual match appears to be improved, even if the colour match per se is a bit less.
An alternative embodiment of the present invention, involves using a database of colour formulations, from which a best match is selected which subsequently further optimized using the calculation texture model by adapting the toner concentrations to obtain a closer texture match or combined colour and texture match. The adaptations can be small or can require removal of one or more toners or adding one or more new toners to the selected formulation.
The invention also relates to a method for repairing a paint film on a substrate and to a method for matching of a repair paint to texture properties of a paint film on a substrate to be repaired using paint modules with specified texture data, which are used to calculate a combination of paint modules matching the required texture properties, mixing the modules as calculated and applying the resulting paint on the substrate to be refinished. This embodiment enables automated selection of effect toners, which was not possible hitherto. As a result, no inherently inaccurate visual assessment of a colour specialist is required.
Texture can be imaged by means of a digital imaging device, such as a CCD camera. Subsequently, image analysis software can be used to translate the image into one or more texture parameters. Suitable image processing software is for instance Optimas or Image ProPlus, both commercially available from Media Cybernetics, MacScope, available from Mitani Corporation, or Matlab, available from The MathWorks Inc.
DETAILED DESCRIPTION OF THE INVENTION
Measuring Texture
In order to extract a texture parameter from a digital image, a set of representative car colours is collected and judged visually using a reference scale that covers the whole texture parameter range. An algorithm is derived that extracts texture parameter values from the images of the set of car colours that closely correlate to the visual assessments.
The texture parameter “coarseness” describes the visual surface roughness of a sample: a coating shows coarseness when it exhibits a clear pattern of dark and light areas. Not only the ratio between dark and light areas, which for a black and white image can be expressed in a gray value standard deviation, is of importance, but also the size of the areas. For example, the drawings in FIG. 1 have the same gray value standard deviation, but clearly differ in pattern.
To extract coarseness, the following algorithm can be used:
Take a CCD image of N×N pixels. The gray value standard deviation GVSTD is determined at several scales X: At the smallest scale X=1 it is calculated per individual pixel. At the second smallest scale it is calculated over the average gray values of squares of 2×2 pixels (X=4). At the third smallest scale squares of 4×4 pixels are used, so X=16. This is repeated up to the maximum scale of N×N pixels (X=N 2 ).
The gray value standard deviation GVSTD can be described as a function of the scale X using:
GVSTD
=
A
+
B
X
C
(
1
)
With GVSTD and X being known, parameters A, B, and C can be calculated by fitting.
The A, B and C parameters can be correlated to a visual coarseness value VC by:
VC=α 1 +α 2 *A+α 3 *B+α 4 *C (2)
The values for the α 1 , α 2 , α 3 and α 4 have been pre-determined before by comparison with a set of panels of representative car colours. These reference colours are judged by the eye and accorded a value according to a reference scale. Judging is done by a number of people and the accorded values are averaged per panel. For each of these reference colours, the measured VC should be equal to the value according to the reference scale for visual judgment. The parameters α 1 , α 2 , α 3 and α 4 are found by minimizing the difference between observed and measured values for all used panels in the set of representative car colours. To find equal values for the α 1 , α 2 , α 3 and α 4 parameters for all panels of the set of representative car colours, the square value of the difference between the reference scale value and the visual coarseness value VC is calculated for each panel. The sum of all these square values Σ all panels (visual judgment panel i −VC panel i ) 2 is subsequently minimized, resulting in values for α 1 , α 2 , α 3 and α 4 . With these parameters being known, the coarseness of any car paint film can be determined.
The aforementioned method to correlate the coarseness to visual assessments by using the theoretical model (2) can be done in general for any texture parameter for any observation and illumination condition for any particular model. This particular model can include any physical parameter (like particle size, flake composition, etc.), colour parameter (like CIE Lab parameters, etc.) or image parameters (like grey value standard deviation, etc.).
An alternative way to measure texture, in particular so-called micro-brilliance, with a digital imaging device and image analysis software is disclosed in US 2001/0036309, herein incorporated by reference.
The parameter ‘glints’ is another texture parameter, which describes the perception of bright tiny light spots on the surface of an effect coating under directional illumination conditions that switch on and off when you change the viewing angle. Glints is best observed in direct sun light, i.e. with a cloudless sky, from less than one meter. Even when the observation conditions are the same, some effect coatings show many bright glints, whereas other effect coatings show few or even no glints at all. A glint scale has been designed with which an observer can visually inspect the effect coating, and express the glints aspect as a number. Some effect coatings will have a small glints value, others a large glints value. In this way, the texture aspect “glint” of a coating can be observed in a quantitative way.
The texture parameter “glint” can be described more specifically by making the distinction between glint intensity and glint size. Glint intensity is the light intensity or light intensity distribution of the bright tiny light spots. Glint size is the area or area distribution of the spots.
A second way to make a further distinction between glints is by their colour or colour distribution.
A glint is visible only in a given range of mutual orientations of illumination direction, observation direction and sample orientation. As a consequence, a third way to characterize glints is to determine the range of illumination angles (or the distribution thereof) for which a glint is visible to the human eye, given a certain observation angle and sample orientation. Similarly, the range of observation angles (or the distribution thereof) for which a glint is visible to the human eye can be used given a fixed illumination angle and sample orientation, or the range of sample orientations (or the distribution thereof) for which a glint is visible to the human eye, can be used given a fixed observation angle and a fixed illumination angle.
Measuring Colour
Generally, texture matching will be combined with colour matching. To match a colour, the colour has to be measured first. Colours can be measured with the aid of colour meters, such as spectrophotometers or tri-stimulus meters. The measured signals can be used for the determination of a paint formula with a matching colour. US patent application US 2001/0036309 describes a method of measuring colour with the aid of a multi-angle spectrophotometer and using the measured data to search for a colour formula in a databank. U.S. Pat. No. 4,813,000 discloses measuring a selected colour with the aid of a tri-stimulus colour analyser and using the measured chromaticity data to search for a colour formula in a databank. WO 01/25737 discloses how to measure colour with a digital imaging device such as a scanner or a digital camera.
After measuring the texture properties, and optionally also the colour, a matching paint formulation is calculated. To this end, the texture, and optionally colour, of paint formulations is predicted.
Predicting Texture on Basis of Concentrations of Paint Modules
A suitable repair paint is formulated as a mixture of a number of paint modules, e.g., toners, selected from a set of modules. Texture parameters of the modules have been predetermined. Based on these parameters, a mixture can be calculated showing a desired texture parameter. This way, a formulation for a repair paint can be calculated having a texture which closely matches the texture of the original paint film.
The texture of a colour formula can be expressed in visual texture properties like coarseness, sparkling, glints, or micro-brilliance, but also in physical texture properties like particle size, particle size distribution, particle shape, particle colour, and the number of particles, a particle being, e.g., an effect pigment, or a couple of effect particles which cannot directly be distinguished visually or in the image, such as de-orienters.
A texture parameter T of a single colour formula containing V toners each having a texture property c i can be written as:
T i =( c 1 ,c 2 , . . . , c v ) (3)
T i is preferably a visual property, like coarseness, but could also be a physical texture property. For example, a coarseness model for a formulation of a number of v toners could be written as a function of Kubelka-Munk k and s values and the toner concentrations c, measured an optical geometry g and wavelength λ:
T coarseness =( k 1 λg ,k 2 λg , . . . , k v λg ,s 1 λg ,s 2 λg , . . . , s v λg ,c 1 ,c 2 , . . . , c v ) (4)
In this example, the coarseness model uses the same parameters as the colour model (K and S values). This is not always necessary for texture models: a more generic example shows that T i could be dependent on specific texture properties of the toners:
T coarseness =( A 1 ,A 2 , . . . , A v ,B 1 ,B 2 , . . . , B v ,c 1 ,c 2 , . . . , c v ) (5)
where A j is for example the particle area or area distribution of the specific toners, and B j is the particle shape (e.g. major axis length or circularity) of the specific toners. T i can be a visual property like coarseness T coarseness , but can also be, e.g., the overall particle area or area distribution of the colour formula or the overall particle shape in the colour formula.
The texture of a standard paint, e.g., the paint for a car to be repaired, can be expressed in a number texture parameters T i ST . When the texture of this standard paint is to be matched, calculational methods such as for example the least squares method can be used to minimize the following expression by changing the toner concentrations:
X 2 = ∑ i = 1 I { T i ( c 1 , c 2 , … , c v ) - T i ST } 2 ( 6 )
by using a non-linear optimization algorithm like the Marquardt-Levenberg algorithm (as described in Numerical Recipes in Pascal, W. H. Press, B. P. Flannery, S. A. Teukolsky, and W. T Vetterling. Cambridge University Press, 1989). This means that for a single paint formula the toner concentrations are varied in such a way that the theoretical texture differences between the colour formula and a specified target colour is minimized (i.e. X 2 from equation (6) is minimized).
Coarseness
The following is an example of a calculational model for predicting the coarseness of a paint film based on pre-determined coarseness data of paint modules used to formulate the paint. The following general function can be defined to predict the coarseness of a calculated colour formula as the sum of a number of predictors x, each with a weigh factor β:
F=Σβ i *x i (7)
A possible predictor x is for instance the concentration of a toner used in the colour formulation. In Table 1 an example of a colour formula is given:
TABLE 1
Toner
Concentration
Q065 (pigment free binder module)
0.23
Q110 (toner with a solid pigment)
0.17
Q160 (toner with a solid pigment)
0.20
Q811E (toner wit metallic pigment)
0.30
Q811U (toner wit metallic pigment)
0.05
Q951F (toner wit pearlescent pigment)
0.05
Three Possible Predictors x are:
CONCS=Concentration Solids: 0.17+0.20
CONCM=Concentration Metallics: 0.30+0.05
CONCP=Concentration Pearls: 0.05
In this case, the predictors relate to toner types (solids, metallics, pearlescents, etc.). Alternatively, predictors can be used relating to individual toners, but this would generally result in a very large number of predictors. Another option is to use predictors relating to concentrations of solids with a low scattering coefficient (CONCSL), solids with a high scattering coefficient (CONCSH), fine metallics (CONCMF), medium metallics (CONCMM), coarse metallics (CONCMC), pearlescents with a low scattering coefficient (CONCPL), pearlescents with a high scattering coefficient (CONCPH), des-orienter (CONCQ), etc.
It was found that scattering is a good indicator for coarseness. To avoid too many predictors, one can take the sum over the colourant concentrations times the colourant scattering coefficients averaged over the 16 wavelengths at 25°, 45° and 110°. For the metallics in this case this would be for 25°:
SUMMS1=0.30*Average S 25 Q 811 E+ 0.05*Average S 25 Q 811 U (8a)
And for the other angles:
SUMMS2=0.30*Average S 45 Q 811 E+ 0.05*Average S 45 Q 811 U
SUMMS3=0.30*Average S 110 Q 811 E+ 0.05*Average S 110 Q 811 U
Wherein “AverageS 25 Q811E” is the average value of the scattering coefficient over the 16 wavelengths at 25° for toner Q811E and “AverageS 25 Q811U” is the average value of the scattering coefficient over the 16 wavelengths at 25° for toner Q811U, weighed by their respective concentrations as shown in Table 1.
The same can be done for the absorption coefficient. For the metallics in this case this would be for 250:
SUMMK1=0.30*Average K 25 Q 811 E+ 0.05*Average K 25 Q 811 U (8b)
The predictors SUMMS1, SUMMS2, SUMMS3, SUMMK1, SUMMK2, and SUMMK3 are used in equation (7).
Additionally or alternatively, the L, a, b, Munsell chroma and Munsell hue values of the colour at the three angles can be used as predictor. Other predictors that can be thought of are ratio S to K and vice versa, splitting the wavelength domain into two (SUMMS1A and SUMMS1B) or four (SUMMS1A, SUMMS1B, SUMMS1C and SUMMS1D) parts instead of averaging over the whole range, and defining a sort of contrast predictor ([constant−{S/K} solid ]/{S/K} solid ). The number of possible combinations seems countless; however, many are highly correlated.
Generally a number of 6 coarseness classes or categories are defined. Because these categories are used, a logistic regression is applied to predict the coarseness instead of a linear model, the latter would suggest a continuous scale. The function can be written as:
ln ( p ( y ≤ y i ) ( 1 - p ( y ≤ y i ) = α i + F , i = 1 … 5 ( 9 )
with α being the boundaries between categories.
The chance on a certain coarseness value can be calculated as follows:
P (coarseness value=1)= p ( y≦y 1 )
P (coarseness value=2)= p ( y≦y 2 )− p ( y≦y 1 )
P (coarseness value=3)= p ( y≦y 3 )− p ( y≦y 2 )
P (coarseness value=4)= p ( y≦y 4 )− p ( y≦y 3 )
P (coarseness value=5)= p ( y≦y 5 )− p ( y≦y 4 )
P (coarseness value=6)=1 −p ( y≦y 5 )
FIG. 2 shows an example of a chance distribution. As coarseness value either the median, mode or Σi*P(i) with i=1 to 6 is taken.
The values for the α's and β's are pre-determined by comparison with a set of panels of representative car colours. These reference colours are judged by the eye and accorded a value according to a reference scale. This is done by a number of people and the accorded values are averaged per panel. For each of these reference colours, the predicted coarseness value should be equal to the value according to the reference scale for visual judgment. The parameters are found by minimizing the difference between observed and measured values for all used panels in the set of representative car colours. With these parameters being known, the coarseness of any car paint film can be predicted.
Glints
A glints model has been designed in order to predict the glint number of an effect coating, based on only the concentrations of the various toners used in the paint. The model may be used when trying to match an original colour, e.g., of a car to be refinished. In that case, the model can make sure that also the glint aspect of the original car colour is matched.
In order to make these predictions, the glint model requires a number of input parameters:
the illumination and observation angles. This means the angle from which the light source (for example, the sun) is shining on the coating, and the angle at which the observer is looking to it. Also the distance from which the light source is shining, and the distance between observer and coating are relevant. The intensity of the light source is also needed. And finally, the angular scope of detector/observer's eye and light source, as seen from the coating. Sizes and thicknesses and number of flake particles inside effect toners. The orientations in which the flakes for each toner are lying in a coating The absorption and scattering (K&S) values of the non-effect toners, and the refractive index of the non-effect toners. These are used to calculate how the coating absorbs light.
First the colour and intensity of the background, i.e. the coating surrounding glints, are calculated. This is important, because the human eye can detect a tiny light source like a glint better when it has a dark surrounding than when it has a lighter surrounding. The background colour is calculated based on the absorption and scattering (K&S) values of the non-effect toners, under the assumption that all light falling on an effect coating is either absorbed or reflected by a flake at some depth in the coating. The various contributions from flakes at several depths in the coating are all taken into account.
After calculating the background colour and intensity, it is calculated how intense a glint should be, in order to make it visible for the human eye, against the calculated background. The calculation is done as described in the article of hardy, J. Opt. Soc. Am 57 (1967) 44-47. Next, it is calculated how many flakes under one square centimeter of coating surface have the right orientation and depth in the coating, such that the light reflected from them is intense enough to be visible against the background. This number is called N and is found by multiplying four terms. The first term accounts for the fact that glints are more easily recognizable against a darker background, and deals with light absorption by solid pigments. The second term accounts for the dependence on viewing/illumination angle. The third term accounts for the concentration of flakes in the coating, and the fourth term calculates the fraction of flakes that have the correct orientation in order to make them visible as glint.
Now using the psychologically based Weber law that human perception is often based on the logarithm of stimulus, the logarithm of N is correlated with the visually observed glint scale numbers. The Weber law is described in M. W. Levine, Fundamentals of Sensation and Perception, 3 ed., Oxford University Press, New York, 2000. Now using the psychologically based Weber law that human perception is often based on the logarithm of stimulus, the logarithm of N is correlated with the visually observed glint scale numbers.
Matching Colour on Basis of Concentrations of Paint Modules
Colour formulas can be determined in a number of ways, i.e. by means of search procedures, calculations, or combinations of the two. For example, use may be made of a databank comprising colour formulas having colorimetric data linked thereto. Using the calculated colorimetric data of the measured selected colour, the most closely matching colour formula can be found. Alternatively, it is possible to use a databank having colour formulas with spectral data linked thereto. Known calculation methods can be used to calculate the colorimetric data of the colour formulas and compare them. Also, a databank can be used in which the absorption and reflection data, the so-called K and S data, of pigments are stored. Using K and S data in combination with pigment concentrations makes it possible to calculate the colour formula of which the colorimetric data most closely match the colorimetric data of the measured selected colour. The methods in question have been described in detail in D. B. Judd et al., Colour in Business, Science and Industry . It is possible to combine the aforesaid search and calculation methods.
Colour can be expressed by the paint film reflection as a function of wavelength of visible light. Alternatively, colour can be expressed in accordance with the so-called CIE Lab system, as defined by the Commission International d'Eclairage, or similar systems, such as the CIE Luv, CIE XYZ systems or the Munsell system. In paint films comprising effect pigments, the measured reflection R is dependent on the optical geometry, which is defined by the angle of observation and the angle of illumination. The theoretical reflection R gλ at a wavelength λ and at optical geometry g of a colour formulation composed by a number of v toners, can be written as a function of the colorimetric parameters c of each toner:
R gλ =( c 1 ,c 2 , . . . c v ) (10)
Alternatively, the L,a,b values of a paint formula can be written in a similar way.
This colour formula contains V toners, g measuring geometries, and λ wavelengths per geometry. Generally, g=1 in case of solid colours without effect pigments, and λ=16 when the wavelength range is between 400 and 700 nm and the wavelength interval is 20 nm. For paints comprising effect pigments, g is usually about 3.
In accordance with the Kubelka Munk model (the hiding version) the reflection R KM is defined by the following formula:
∑ i = 1 V c i · K g λ i ∑ V i = 1 c i · S g λ i = ( 1 - R g λ KM ) 2 2 R g λ KM ( 11 )
in which K i gλ is the absorption factor at wavelength λ and optical geometry g of toner i and S i gλ is the scattering factor at wavelength λ and optical geometry g of toner i. Hence, a similar formula as equation (4) is obtained:
R gλ (K 1 gλ ,K 2 gλ , . . . , K V gλ ,S 1 gλ ,S 2 gλ , . . . , S V gλ ,c 1 ,c 2 , . . . , c v ) (12)
In order to match a standard colour (e.g. the colour of the car to be repaired) expressed in reflection values R ST gλ , for example the least squares method can be used to minimize the following expression:
X 2 = ∑ g = 1 G ∑ λ = 1 Λ { R g λ ( c 1 , c 2 , … , c v ) - R g λ ST } 2 ( 13 )
by using a non-linear optimization algorithm like the Marquardt-Levenberg algorithm. This means that for a single colour formula the toner concentrations are varied in such a way that the theoretical colour difference between the colour formula and a specified target colour is minimized (i.e. X 2 from equation (13) is minimized). The concentrations c i of V different toners in one colour formula are estimated by fitting the c i parameters in the following equation using fixed K and S values for each toner:
R gλ (fit parameters:c 1 ,c 2 , . . . , c V ;fixed:K 1 gλ ,K 2 gλ , . . . , K V gλ ,S 1 gλ ,S 2 gλ , . . . , S V gλ ) (14)
This way of representing colour formulation also incorporates the cases for which toners are omitted from or added to a colour formula: this can be achieved by setting the accompanied toner concentrations to zero, or removing the parameter respectively.
Combined Colour and Texture Matching
The preferred way to cope with texture parameters is to match a paint based on colour and texture simultaneously. To this end, a combined colour and texture model “RT” has to be defined. This can for example be done by combining equations 6 and 13, i.e. by adding them up and defining a weigh factor α, ranging between 0 and 1:
X
2
=
(
1
-
α
)
·
∑
g
=
1
G
∑
λ
=
1
Λ
{
R
g
λ
(
c
1
,
c
2
,
…
,
c
v
)
-
R
g
λ
ST
}
2
+
α
·
∑
i
=
1
I
{
T
i
(
c
1
,
c
2
,
…
,
c
v
)
-
T
i
ST
}
2
(
15
)
Equation (15) is minimized by using a non-linear optimization algorithm like the Marquardt-Levenberg algorithm. The fit parameters are the toner concentrations, and the fixed parameters are the K and S values from the colour model and the texture parameters from the texture model.
The weigh factor α can be used to set the priority between colour and texture. If the colour match is given more priority than the texture match, then α is less than 0.5, while if the texture match is given more priority, then α is more than 0.5. The higher the value of α, the more important the role of texture. The factor α can be kept constant for all colour formulas, but can also be varied for each separate colour formula.
An alternative way to deal with texture is using texture as a constraint during a more or less standard colour formulation. This means that equation (13) is solved instead of equation (15), but during the estimation the toner concentrations are not allowed to vary in such a way that the texture parameter differences T i (c 1 , c 2 , . . . , c v )−T i ST exceed predetermined upper and lower limits.
FIG. 3 shows a schematic example how to use equation (15), dividing X 2 in a colour part and a texture part:
X 2 =(1−α)· X Color 2 +α·X Texture 2 (16)
FIG. 3 shows graphically the function of equation 16 for a specific colour formula. When the formula is matched on colour only (α=0) then X 2 colour (dark blue line) is in this particular case lower than the colour acceptance threshold (pink line) which means that the colour is visually acceptable according to the average colour specialist. However, X 2 texture (yellow line) is quite large and in this particular case larger than the texture threshold (cyan line), which means that the texture is visually not acceptable for the average colour specialist. When, on the other hand, a match is based on texture only (α=1) then the colour is not acceptable while the texture is acceptable. To obtain a satisfactory match, both X 2 colour and X 2 texture must be lower than the corresponding thresholds. This is achieved in this particular example when 0.2≦α≦0.6. It is emphasized that this is just an example. There will always be colour formulas for which either the colour and/or texture will or cannot become lower than their visual thresholds. This is for example the case when the toners have not been selected correctly.
There are different ways to deal with the weighing factor α. One way is to set α to a fixed value that on average enables the best combined colour and texture match. A more preferred way is to determine an optimum value α specifically for each separate colour formula.
The invention is further explained by the following example.
Example
A dark gray effect coating (“standard”) was measured at three angles (25°, 45° and 110°) with a ColourChecker. Table 2 shows the measurement results.
TABLE 2
“Standard”
L*
a*
b*
25°
26.71
−1.57
−4.59
45°
10.73
0.9
−2.54
110°
4.62
1.73
−0.44
As texture property the coarseness was measured and indexed at 0.91.
An effort was made to match on colour only (“colour”) and on colour and texture (“coltex”). For both calculations the same set of colourants was used. Recipes were sprayed out and samples measurements. Recipes are given in Tables 3, colour measurements results in Tables 4 and 5. For “colour” the coarseness value was 2.24 and for “coltex” 1.23, coarseness differences with the standard are given in Table 6.
TABLE 3
Recipes “Colour” and “ColTex”
“Colour”
“ColTex”
Colourant
Amount (part by weight)
Amount (part by weight)
Toner A
3.22
2.85
Toner B
47.92
53.30
Toner C
3.00
0.00
Toner D
4.39
5.82
Toner E
15.07
13.52
Toner F
12.89
11.39
Toner G
7.87
8.06
Toner H
5.64
5.07
TABLE 4
“Colour”
ΔL*
Δa*
Δb*
25°
−0.56
−0.31
0.01
45°
0.09
−0.24
−0.02
110°
0.21
0.11
0.36
TABLE 5
“ColTex”
ΔL*
Δa*
Δb*
25°
−0.58
−0.75
−0.35
45°
0.2
−0.46
−0.3
110°
0.23
−0.11
0.03
TABLE 6
ΔCoarseness “Colour” and “ColTex”
(criterion ΔCoarseness ≦ 0.8)
“Colour”
“ColTex”
ΔCoarseness
1.33
0.32
Using the weight averaged ΔEcmc (WADE), “colour” scores 0.46 and “coltex” 0.68. This example shows the added value of texture matching: the texture of “coltex” matches the texture of “standard”, is a bit more off in colour than “colour”, but satisfies the requirement WADE<1.
|
A method for matching colour properties and texture properties of a repair paint to colour properties and texture properties of a paint film on a substrate to be repaired is provided. In the method, the texture of the paint film is imaged with a digital imaging device, the imaged texture is analyzed using image analysis software, texture data is calculated, and the repair paint is formulated on the basis of the concentrations of paint modules, wherein each paint module is associated to specified texture data and colour data.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to the French application 1554713 filed May 26, 2015, which applications are incorporated herein by reference and made a part hereof.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns the field of lighting modules and notably lighting modules for communicating motor vehicles.
2. Description of the Related Art
When communication/detection devices are used in a motor vehicle, a dedicated module is usually installed, for example, behind the windshield or in the bumper.
These communication/detection devices can employ various technologies (infrared, electromagnetic, etc.) in order to detect some obstacles or to communicate with other vehicles (e.g. transmission of information relating to speed, braking, roadholding, etc.).
These communication/detection devices can generate disabling mechanical integration constraints because of their bulk and the necessity to supply these devices with electrical power.
Thus, there exists a requirement to simplify (or even to eliminate) the mechanical integration constraints of these devices.
Moreover, the communication/detection devices can suffer from a limited communication/detection range. If this range can be linked to a power of the communication means (e.g. an emitter of visible light), it is difficult to envisage increasing the overall power of these communication means installed on the vehicle: indeed, these communication means could dazzle other road users if the overall power used were too great.
Thus there exists a requirement to increase the range of the communication/detection devices used in a vehicle without this increasing the overall power of those means.
SUMMARY OF THE INVENTION
The present invention improves on the situation.
To this end, the present invention proposes a light-emitting device, notably a lighting and/or signaling device for a motor vehicle, including:
at least one first light source intended to emit a first modulated light beam coding information;
at least one second light source intended to emit a second modulated light beam coding information;
a control device adapted:
to determine, on receiving information to be transmitted via the light-emitting device, if a first light beam intended to be emitted by the first source should be modulated to code the information to be transmitted and/or if a second beam intended to be emitted by the second source should be modulated to code the information to be transmitted, the determination depending on information relating to the local solar illumination; as a function of the determination, to modulate the first light beam and/or the energization second light beam to code the information to be transmitted.
The determination step effected by the controller makes it possible to choose via which light source the information to be transmitted will be emitted. Indeed, the variation of the energization signal of the light sources can make it possible to cause those sources to blink and thus can make it possible to code information in the form of light variations.
The fact of choosing the light source to be used for such transmission (and thus choosing which energization signal to modify) can make it possible to determine the most relevant source for such transmission (e.g. main beams when turned on, DRL when the other lights are turned off). This determination therefore makes it possible to guarantee an optimum transmission quality.
The controller can be adapted to control all of the actions necessary to implement the invention.
The controller can advantageously be adapted:
on reception of information to be transmitted via the light-emitting device, to determine if a first energization signal of the at least one first source should be modified to code the information to be transmitted and/or if a second energization signal of the at least one second source should be modified to code the information to be transmitted, the determination depending on at least one item of information relating to energization of the first source:
as a function of the determination, to modify the first energization signal and/or the second energization signal to code the information to be transmitted.
It is therefore clear that in this embodiment the information relating to the local solar illumination is determined by the presence of an energization signal of the first source. For example, if the first source is intended to provide a daylight running lights (DRL) function, the presence of an energization signal of this first source makes it possible to determine that this occurs during daylight hours and that there is therefore local solar illumination. Alternatively, if the first source is intended to provide a nighttime signaling or lighting function, for example a high beam function, the presence of an energization signal of that first source makes it possible to determine that it is nighttime and therefore that there is no local solar illumination.
In one particular embodiment, the first light source or the second light source may include a semiconductor chip, notably an LED (light-emitting diode). Indeed, the light variations of semiconductor chips can be very rapid and the coding of information by blinking light can then can be imperceptible to the human eye whilst being detectable by appropriate measuring tools.
The semiconductor chips may be arranged as a single electronic component, for example a two-chip or multichip LED.
Moreover, the first light source may be adapted to emit visible light while the second light source may be adapted to emit infrared light.
Thus, the second light source may serve as transmission means when the first source is not lit (e.g. daylight driving with no high beams) or the first source is weakly lit (e.g. on standby). This second source then makes possible transmission that is invisible to the human eye.
The control device may for example include means for detecting energization of the first source, the information relating to the local solar illumination depending on the detection.
In addition to this or instead of this, the control device may include a solar sensor.
In one embodiment, the control device may be adapted to command, as a function of the determination, the emission of a single light beam by a single one of the first and second light sources and to modulate, as a function of the determination, the light beam to code the information to be transmitted.
Where necessary, the control device may be adapted to command the turning off of the other of the first and second light sources during the emission of the single light beam during daylight hours.
In one embodiment of the invention in which the first light source emits visible light and the second source infrared light, the control device is adapted to command, at night, the emission of a visible light beam by the first light source to provide a lighting and/or signaling function and to modulate that visible light beam to code the information to be transmitted, the infrared diode being kept turned off by the control device.
The control device may equally be adapted to command, as a function of the determination, the emission of a first light beam by the first light source and a second light beam by the second light source and to modulate, as a function of the determination, a single one of the first and second light beams to code the information to be transmitted.
Where necessary, the control device is adapted to command the simultaneous emission of the first and second light beams.
In one embodiment of the invention in which the first light source emits visible light and the second source infrared light, the control device is adapted to command, during daylight hours, the emission of a visible light beam by the first light source to provide a lighting and/or signaling function and to command the emission of an infrared light beam by the second light source and to modulate that infrared light beam to code the information to be transmitted.
Moreover, the controller may be configured to effect the modification of the first energization signal at a first coding frequency lower than a second coding frequency used to effect the modification of the second energization signal.
Indeed, the transmission performance (i.e. transmission errors, transmission range, etc.) of the various light sources may be different. In particular, it is found that transmission performance is higher for infrared light sources compared to visible light sources. This being so, it is possible to use a higher transmission (and therefore coding) frequency for the sources that offer higher performance.
In one embodiment of the invention, the device may include at least one headlight assembly. The first light source and/or the second light source may then be installed in the headlight assembly.
This installation makes it possible to simplify the mechanical installation constraints and, for example, to combine the existing lighting/signaling devices (i.e. headlights, position lights, reversing lights, fog lights, DRL, turn indicators, etc.) with the transmission/detection devices.
For example, the controller may be adapted to determine that the second energization signal must be modified if the energization of the first source is below a predetermined threshold.
Thus if it is determined that the first source is not powerful enough, it is possible to use instead or in addition the second light source as transmission/detection device.
Moreover, the controller may be adapted to determine that the first energization signal must not be modified if the energization of the first source is below a predetermined threshold.
Thus if it is determined that the first source is not powerful enough, it is possible to use instead the second light source as transmission/detection device.
The device may advantageously further include an optical device having a focus. The first light source and the second light source can then be installed in the vicinity of the focus.
In one particular embodiment, the device may further include a reflector. The first light source and the second light source can then be installed facing the reflector.
This installation makes it possible to produce a compact system combining lighting/signaling device and transmission/detection device. Moreover, the direction of the light emitted by each of the light sources may be reflected in the same direction without it being necessary to install a plurality of reflectors.
The device may further include:
a waveguide;
a reflector.
The first light source and the second light source can then be installed facing the waveguide and the waveguide can be installed facing the reflector.
Similarly, the device may further include:
a primary optical device having two light entry faces and one light exit face;
a secondary optical device having a focus.
The first light source and the second light source are then each installed facing one of the light entry faces of the primary optical device.
The exit face of the primary device is then installed at the focus of the secondary optical device.
In one embodiment, a frequency for coding the information to be transmitted on modification of the first signal and/or the second signal may be greater than 25 Hz.
Thus any blinking of the light source is imperceptible to the human eye.
Moreover, the controller may be configured to reduce the coding frequency of information should at least one of the following conditions apply:
an error rate during a preceding transmission has exceeded a predetermined value;
information is received relating to a presence of rain or fog.
Thus if the environmental conditions are not favorable, it is possible to reduce the coding frequency to render the transmission more robust.
The present invention is further directed to a light-emitting device, notably lighting and/or signaling device for a motor vehicle, including:
a light source;
a controller adapted:
to modify an energization signal of the light source to code information to be transmitted, the modification of the signal including multiplication of the energization signal with a coding signal including forms repeated in the signal, the forms having a given temporal extension and an amplitude, on reception of a command, to reduce the temporal extension of the forms and to increase the amplitude of the forms in the signal.
For example, the forms repeated in the signal may be pulses or similar forms (triangular, Gaussian, part-sinusoidal, etc. forms).
The amplitude of these forms is often the maximum value of these forms during their temporal extension (excluding interference or noise in the signal linked to the coding, for example).
The conjoint reduction of the temporal extension of the forms and the increase of the amplitude make it possible to increase the power of the light pulses emitted by the light sources (and therefore the transmission range of the sources) at the same time as avoiding dazzling a road user.
In one embodiment, the controller may be adapted to modify the energization signal in accordance with a Manchester code.
Indeed, that code having a zero average coding signal makes it possible to produce a light source having an apparently constant lighting power. Moreover, that code makes it possible to prevent synchronization losses. Moreover, it is robust against interference.
Moreover, the reduction of the temporal extension may be a function of the increase of the amplitude.
This “function” may be based on calibration of the luminous power of the light source as a function of the received electrical power. Indeed, the response is not necessarily linear.
Of course, the reduction of the temporal extension may be proportional to the increase of the amplitude.
On this assumption, it is possible to produce simple control devices of relatively low cost because the linearity of the response of the lighting power as a function of the electrical power is, to the first order, a reliable approximation.
In one embodiment, the coding signal including a coding frequency, the coding frequency is retained on reducing the temporal extension of the forms.
Indeed, the fact that the temporal extension of the forms repeated in the signal is reduced does not necessarily mean that the frequency of appearance of those forms is increased. This point is demonstrated by FIG. 3 b below.
These and other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Other features and advantages of the invention will become more apparent on reading the following description. The latter is purely illustrative and must be read in conjunction with the appended drawings, in which:
FIG. 1 shows communication between two motor vehicles in one particular embodiment of the invention;
FIGS. 2 a and 2 b show light-emitting devices, notably lighting and/or signaling devices for motor vehicles in two embodiments of the invention; and
FIGS. 3 a and 3 b show energization signals of lighting devices in accordance with some embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows communication between two motor vehicles 100 , 102 in one particular embodiment of the invention.
During travel in a motor vehicle 100 , 102 , it may be useful for that motor vehicle 100 , 102 to interact with its near environment: possible obstacles, nearby cars, road signs, etc.
Indeed, these interactions can make it possible for the motor vehicle 100 , 102 to adapt the driving conditions offered to the driver of the motor vehicle 100 , 102 . Without this being limiting on the invention, these interactions may include:
the reception/transmission from a road sign of the maximum speed allowed on a road in order for the motor vehicle 100 , 102 to be able to configure a speed “limiter” of the motor vehicle 100 , 102 ;
the reception/transmission of the current driving speed of the vehicle/other nearby motor vehicles 100 , 102 in order to adapt the current speed to the average speed of the other motor vehicles 100 , 102 ;
the estimation of the distances of other motor vehicles 100 , 102 ;
the reception/transmission of sudden braking information in order for the other motor vehicles 100 , 102 to be able to act accordingly (e.g. braking and turning on of emergency lights);
etc.
As indicated above, it is advantageously possible to use the existing lighting or signaling devices (e.g. LED headlights 101 a , daylight running lights (DRL) 101 b , position lights, fog lights 101 c or 102 b , in the rear lights 102 a , etc.) in order to serve as emitters of the communication/detection devices.
The combination of the existing lighting or signaling devices 101 a , 101 b , 101 c , 102 b , 102 a and the emitters of the communication/detection devices therefore makes it possible to gain a significant amount of space and to reduce the mechanical installation constraints.
Thus if the existing lighting or signaling devices 101 a , 101 b , 101 c , 102 b , 102 a are turned on (e.g. the driver has wanted their headlights to be turned on), it is possible to cause these lighting or signaling devices 101 a , 101 b , 101 c , 102 b , 102 a to blink at a high frequency in order to be able to transmit information and thus to be able to cause these lighting or signaling devices 101 a , 101 b , 101 c , 102 b , 102 a to operate as emitters of communication/detection devices.
Of course, the blinking of these lighting or signaling devices 101 a , 101 b , 101 c , 102 b , 102 a must be sufficiently fast to prevent the human eye detecting this blinking or for the latter to cause visual fatigue. This being so, the blinking frequency used is advantageously higher than the reciprocal of the retinal persistence time (>=25 Hz).
It is possible for the type of lighting or signaling devices 101 a , 101 b , 101 c , 102 b , 102 a used to limit the blinking frequency: indeed, some bulbs/LED or other semiconductor emitter chips may have maximum frequencies beyond which the lighting or signaling device 101 a , 101 b , 101 c , 102 b , 102 a deteriorates or beyond which the blinking is no longer visible (the lighting or signaling device 101 a , 101 b , 101 c , 102 b , 102 a then emitting light continuously).
Nevertheless, and for LED or other semiconductor emitting chips, it is common for them to be able to blink at frequencies of the order of a few hundred Hertz (e.g. 100 Hz, 200 Hz, 500 Hz).
If it is advantageous to cause the lighting or signaling devices 101 a , 101 b , 101 c , 102 b , 102 a to blink at frequencies close to their maximum blinking frequency (e.g. 10% below their maximum blinking frequency) (the speed of transmission of the data then being at a maximum), that frequency may be dynamically reduced under certain conditions:
presence of fog or rain (information obtained via the rain detectors on the windshield, for example, via the turning on of the windshield wipers by the driver, via meteorological data from the internet, etc.)
error relates detected during a preceding transmission above a predetermined threshold;
etc.
The dynamic reduction of the frequency therefore makes it possible for the communication/detection channel to continue to be reliable despite the fact that the transmission conditions are deteriorating.
Instead of or in addition to this frequency reduction, it is possible to introduce an error corrector code into the transmission or to strengthen the error corrector code that exists already.
The blinking may be complete blinking of the light source (i.e. a time period during which the source is emitting, a time period during which the source is not emitting), but this blinking may also be a partial blinking (i.e. variation of the luminous intensity of the light source between two non-zero values). In order to produce this blinking, it is possible to combine with the supply voltage of the light source an information signal of appropriate frequency (i.e. a few hundred Hertz as mentioned above).
Moreover, the frequency may be variable as a function of the light source used. Indeed, it is found that the quality of the transmission can be better for infrared light sources (for example). This being so, the frequency used may be higher for this type of light sources.
FIGS. 2 a and 2 b show light-emitting devices, notably lighting and/or signaling devices 200 for motor vehicles in two embodiments of the invention.
In FIG. 2 a , the vehicle lighting device 200 comprises:
a housing 201 (including a transparent or at least translucent front part);
a set of high-power lighting diode(s) 202 that can operate as low beams (for example);
a first reflector 205 adapted to direct the light rays coming from the lighting diodes 202 toward the transparent/translucent part of the housing 201 ;
a set of signaling diode(s) 203 (of lower power than the lighting diodes 202 ) that can operate as daylight running lights (for example);
a second reflector 204 adapted to direct the light rays coming from the signaling diodes 203 toward the transparent/translucent part of the housing 201 .
In this embodiment, it is possible to use the set of lighting diode(s) 202 as communication/detection devices when this set of lighting diode(s) 202 is energized (i.e. when the low beams are necessary for driving and/or activated by the driver). If this set of lighting diode(s) 202 is not energized, it is then possible to energize the daylight running lights (the set of signaling diode(s) 203 ) and to use the latter lights as communication/detection devices.
This being so, there are activated communication/detection devices in the lighting device 200 at all times (day and night).
Of course, the daylight running lights may be outside the headlight assembly or housing 201 .
In FIG. 2 b , the vehicle lighting device 200 comprises:
a housing 201 (including a transparent or at least translucent front part);
a set of high-power lighting diode(s) 202 that can operate as low beam or high beam (for example);
a set of high-power infrared (IR) diode(s) 206 ;
an optional waveguide (or light guide) 207 ;
a first reflector 205 adapted to direct toward the transparent/translucent part of the housing 201 the light/IR rays coming from the lighting diodes 202 and the infrared diodes 206 (where necessary, the light/IR rays pass through the waveguide 207 before being reflected at the first reflector 205 );
a set of signaling diode(s) 203 (of lower power than the lighting diodes 202 ) that can operate as daylight running lights (for example);
a second reflector 204 adapted to direct the light rays coming from the signaling diodes 203 toward the transparent/translucent part of the housing 201 .
In this embodiment it is possible to use the set of lighting diode(s) 202 as communication/detection devices when this set of lighting diode(s) 202 is energized (i.e. when the low beams are necessary for driving and/or activated by the driver).
The waveguide 207 is optional in this embodiment. Thus it is possible to dispense with it by positioning the two sets of diode(s), the lighting diodes 202 and the infrared diodes 206 side by side, for example, close to the optical center of the first reflector 205 .
In addition to this or instead of this, when this set of lighting diode(s) 202 is not energized, it is possible to use the set of IR or infrared diode(s) 206 as communication/detection devices.
Assuming that the set of IR or infrared diode(s) 206 is used in addition to the set of lighting diode(s) 202 as communication/detection devices, it is possible:
for these two sets of diodes 206 , 202 to transmit the same information simultaneously;
for one of the two sets of diodes 206 or 202 to transmit a portion of the information to be transmitted while the second set of diodes 206 or 202 transmits the complementary portion;
for one of the two sets of diodes 206 or 202 to transmit the information to be transmitted while the second set of diodes 206 or 202 transmits an error corrector code for that same information.
Thus if the low beams are not being used, the set of IR or infrared diode(s) 206 can make it possible to transmit information without that transmission being visible to road users and without it being necessary to turn on the (visible) lights of the motor vehicle 100 , 102 to enable this transmission.
Of course, it is possible to combine the embodiments shown in FIGS. 2 a and 2 b.
The set or sets of diodes 206 or 202 used as emitters of a communication/detection device may be chosen by a control circuit, either integrated into the lighting device 200 or not. That control circuit (not shown) therefore receives the information to be transmitted via an interface provided for this purpose and determines the set or sets of diodes 206 or 202 to be caused to blink.
This circuit may be, for example:
a processor in the form of a computer program adapted to interpret instructions, or
an electronic circuit card the operation of which is defined in the silicon, or again
a programmable electronic chip such as an FPGA (Field-Programmable Gate Array).
Moreover, it is equally possible for the visible light beam emitted by the lighting diode 202 to be masked for certain areas in space (e.g. masking of the high beams to avoid dazzling a driver approaching in the opposite direction) whereas the infrared beam emitted by the infrared diode 206 is not masked in those areas. This is notably possible using a mask blocking only some wavelengths or providing, at least in part, different optical paths for the different beams (the masking occurring on an optical path on which the beams are separate).
By way of nonlimiting illustration, the various visible light sources in a vehicle may be:
at the front:
“low beam” lights; “high beam” lights; DRL; “sidelights”; laser spotlights; position lights (marking lights);
at the rear:
position lights; stoplights; foglights; reversing lights.
FIGS. 3 a and 3 b show energization signals of light-emitting devices in accordance with some embodiments of the invention.
In the embodiment shown in FIG. 3 a , the energization or pulse signal 300 of the light-emitting device is not a constant current: here the energization signal is a pulse energization signal with period 2 t 0 and amplitude A 0 .
This pulse signal 300 notably enables so-called Manchester coding of the information to be transmitted.
For example, before any transmission of information begins, it is possible to emit a standard pattern 301 shared at least by the emitter and the receiver. This standard pattern 301 enables the receiver to recognize a start of transmission and to synchronize its internal clock to the clock of the emitter.
Following on from this standard pattern 301 , the information bits are coded over a period, the part of the signal 302 corresponding for example to a 0 bit and the part of the signal 303 corresponding for example to a 1 bit.
The average amplitude of the signal is A 0 /2. Accordingly, if the required amplitude for the lighting or signaling device is A 1 (i.e. no blinking), the value is A 0 is chosen as being twice the amplitude of A 1 when blinking is activated by the control circuit.
Moreover, there may arise situations in which the amplitude A 0 cannot provide a sufficient transmission distance (the distance effectively depending on this amplitude): this is notably the case if the sets of diodes used as communication/detection devices are not intended to cast light far from the vehicle, but only intended to be seen (e.g. the daylight running lights, stop lights, position lights, etc.). On these assumptions, it is possible for the energization amplitude of these sets of diodes to be increased by a factor N (e.g. by a factor of two as shown in FIG. 3 b ).
To prevent the luminous intensity perceived by the driver (or any other person) increasing, it is then possible to reduce the periods of emission of light by the same factor N (e.g. t 0 /2 as shown in FIG. 3 b ). Because the efficacy of the emitter can decrease when the amplitude A 0 increases, it must be taken into consideration with the aim of guaranteeing a constant luminous intensity perceived by the driver.
Therefore, in the embodiment shown in FIG. 3 b , the energization signal 300 of the light-emitting device is a pulse energization signal with period 2 t 0 and amplitude 2 A 0 . The pattern 301 is then converted into the pattern 311 . Moreover, the bits are coded using the signal parts 312 and 313 .
Of course, the factor N can take numerous values such as 3, 4, 5 or 6. This factor N can be adapted as a function of the necessary transmission distance imperatives and/or as a function of the inherent characteristics of the light source (e.g. maximum voltage or intensity).
Of course, the present invention is not limited to the embodiments described above by way of example; it is encompasses other variants.
For example, it is possible to use any code for the transmission of the data other than the Manchester code described above. For example, it is possible to use a differential Manchester code, a Miller code, an NRZ (Non Return to Zero) code, an NRZI (Non Return to Zero Inverted) code, an NRZM (Non Return to Zero Mark) code, an RZ (Return to Zero) code or any other code. Of course, if the list of the listed codes contains only so-called two-level (of amplitude) codes, it is equally possible to use codes having more levels (e.g. AMI, Bipolar, BHDn, B8ZS, HDB3, MLT-3, etc.).
Moreover, the diodes of the description may be replaced by lasers or laser diodes. Using lasers or laser diodes makes directional communication possible and makes it possible to increase the communication range for an equivalent power.
While the system, apparatus, process and method herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise system, apparatus, process and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.
|
A light-emitting device, notably a lighting and/or signaling device for a motor vehicle, including at least one first light source intended to emit a first modulated light beam coding information; at least one second light source intended to emit a second modulated light beam coding information; a control device adapted: to determine, on receiving information to be transmitted via the light-emitting device, if a first light beam intended to be emitted by the first source should be modulated to code the information to be transmitted and/or if a second beam intended to be emitted by the second source should be modulated to code the information to be transmitted, the determination depending on information relating to the local solar illumination; as a function of the determination, to modulate the first light beam and/or the energization second light beam to code the information to be transmitted.
| 1
|
BACKGROUND OF THE INVENTION
The present invention relates to the hardware of digital systems, and in particular, it relates to a method and respective hardware logic circuit for implementing partially programmable Finite State Machines.
Developing a complex VLSI-chip is, despite all the verification tools like simulation and formal verification, still an error prone process. Experience shows that usually, there are some errors after the silicon has been built, i.e., the chip is present in hardware form. Typically, those errors are located in the control logic of the chip and not in the data flow logic.
Finite State Machines are the main prior art means to implement the control logic of a digital design. There are numerous tools available, which support the design of such machines. Typically the bugs are associated with the FSMs and it would be highly desirable to make those machines programmable. Full programmability is possible using RAM based techniques; however, the circuit costs are usually prohibitive.
Prior art Finite State Machines (FSM) on the one hand are widely used to implement said control logic. Errors occurring in the state machine cannot be repaired in prior art. After having recognized that an error is present, the chip/circuit logic must be corrected and the hardware must be newly built in silicon.
Another approach to implement the control logic is highly theoretic and not reduced to useful practice until now. This approach would include using fully programmable RAM-based techniques, which generates, however, much too high cost.
Thus, hard-wired technology is preferred to implement said error-prone control logic, and hardware developers suffer from longer development periods required to repeat the “Cementation” of the control logic into silicon “hard wiring”.
The principle of a “hard wired” finite state machine is shown in FIG. 1 :
It consists essentially of a state register 10 , which holds the current state and two functions of 12 , and nf 14 to calculate the outputs and the next state, respectively. The functions “nf” for the next state function and “of” for the current output may be implemented as combinational logic as shown in FIG. 1 or with a RAM as mentioned above.
The U.S. Pat. No. 5,825,199 discloses the need for providing a reprogrammable state machine. Further, general requirements are set up which should be fulfilled with such reprogrammable state machine, as are:
It should be implemented using a minimal amount of silicon real estate,
the mechanism should have a minimal affect on the timing and performance of the state machine since state machines are very critical in timing, and the programming mechanism should be flexible in that it should allow for the reprogramming of the behavior of the state machine arbitrarily within the limits of state bits, inputs and outputs, and using a reasonable number of logic terms.
Further, in said prior art document, it is disclosed that the improved reprogrammable state machine comprises a programmable logic unit in form of a programmable logic array (PLA), which preferably represents a standard sum of products PLA. This is preferred since it represents the best compromise between silicon area and flexibility. Further, the possibility is disclosed, to use a programmable random access memory (RAM) based PLA, which, however, is stated to be time critical in performance.
Further, a vague and insufficiently enabling teaching is given including a ROM, a RAM and a control unit which produce an output, respectively, which is fed at the input of a state machine programmable logic. The control unit is said to be used for loading the RAM unit with the modified values for the state transitions and/or output transitions for each state, which needs to be modified, i.e. corrected due to an error, which has occurred and been detected. This teaching, however, does not represent an enabling disclosure because the state machine reprogrammable logic cannot already include the corrected output signal, as:
a) it is fully unclear, how an error state is detected and controlled, b) it is not at all disclosed how a corrected output value may appear at the output of the state machine, and c) the internal details of the reprogrammable logic of the state machine, which are highly relevant in the underlying context, are not at all disclosed.
Thus, although the before-mentioned U.S. patent has disclosed the need for a reprogrammable state machine of the above-mentioned hardwired type, it does not offer a solution to this problem.
BRIEF SUMMARY OF THE INVENTION
It is thus an objective of the present invention to provide a partly reprogrammable Finite State Machine (FSM), which can be reprogrammed in a limited way such that no costly new physical re-build of the chip including said FSM is required.
According to the broadest aspect of the present invention a partly reprogrammable state machine is disclosed, comprising a state register holding the current state and two functions of, and nf, comprising combinational logic to calculate the outputs and the next state, respectively, said combinational functions being representable in a “sum of products form”, which is characterized by further comprising
a) means for disabling a predetermined number of product terms associated with said “sum of product form”, each product term corresponding to a given state and a given input vector setting, b) means for enabling a predetermined respective number of new product terms each generating a correct output signal corresponding to a given error state and a given error input bit vector, c) whereby said disabling and/or enabling means are provided in a form which allows activation thereof in case a product term was tested to include a bug.
Consequently, the inventive idea allows advantageously to have a FSM with limited programmability which avoids the huge circuit costs associated with RAM based techniques, but which allows to reprogram the behaviour of the FSM in a limited way. This is sufficient, because experience shows that no full programmability of the FSM is required to fix the bugs in the control logic.
Therefore the inventive idea comprises to supplement a hardwired state machine in the following way:
1. allow that each hardwired product term could be disabled, and 2. add programmable product terms which allow to add new behavior to the state machine. Scan-Only Shift Register Latches (SRLs) are preferably used to program the required behavior of those programmable product terms.
The present invention exploits the knowledge that a full programmability of the Finite State Machine (FSM) is not required to cope with the bugs found. In most cases those bugs can be fixed with a small amount of logic; the behavior needs only to be changed slightly. Therefore a new approach is proposed which provides a limited programmability but which avoids the large circuit sizes required for RAM based Finite State Machine implementations.
Further, when the means for disabling a predetermined number of product terms comprises a control SRL, the output of which connects to an AND gate, the input signals of which further comprises signal lines associated with the error state (S 1 ) and the respective input vector (I 1 , I 2 , I 3 ), then an advantageous implementation is provided for a small number of product terms to be corrected.
Further, when the means for disabling a predetermined number of product terms comprises a respective number of disable registers, each associated with a respective decoder, then an advantageous implementation is provided for a larger number (e.g. more than 30) of product terms to be corrected.
When further the means for enabling a new product term comprises
a) an input mask register, b) an input compare register, c) a state compare register, d) an output register, which holds the corrected output signals,
then an advantageous implementation is found for correcting an error-comprising product term.
The same applies for including the next state register, when said state machine further comprises a next state register, which holds the output signals for the next state.
When said state machine further comprises:
a) a means for disabling an error-comprising OTHERWISE logic, and b) a means for enabling a new corrected “OTHERWISE” logic, which comprises logic reflecting enabled new product terms, the inventive approach and the advantages associated with can be extended to situations which include “OTHERWISE” logic branches in the high-level hardware design tool.
When further the means for disabling a predetermined number of product terms, the means for enabling a predetermined respective number of new product terms and a corrected output signal vector is programmed in a content addressable memory (CAM), whereby the error state and the error input vector is used as a search argument into said content addressable memory (CAM), then an alternative way to solve the underlying problem is found.
When, further, a Random Access Memory (RAM) comprises the logic creating a corrected output vector, and a RAM address generation logic is provided for selectively accessing respective RAM entries, and a state machine select logic is provided for selecting between activation of either the regular state machine or the RAM for generating the desired output vector, a further alternative way to solve the underlying problem is found.
When further, the RAM comprises a plurality of compartments, each of them comprising said input mask logic, input compare logic, next state logic and correct product term output signal logic, respectively, then, an advantageous implementation is found for the RAM-alternative.
Thus, many digital circuit chips can take profit by the present invention, and so do the computer systems—small or large in performance—in which such chips are incorporated.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
These and other objects will be apparent to one skilled in the art from the following detailed description of the invention taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic representation illustrating the principle structure of a prior art Finite State Machine (FSM);
FIG. 2 is a prior art state table description;
FIG. 3 is a block diagram representation illustrating the relationship between state tables and “sum of products”;
FIG. 4 is a state table illustration of the basic inventional approach;
FIG. 5 is a block diagram representation illustrating an enable SRL for activating and deactivating a product term according to a preferred embodiment of the invention;
FIG. 6 is an alternative representation preferably used according to a preferred embodiment of the invention;
FIG. 7 is a schematic representation illustrating the inventive principle of providing a programmable product term (PPT) according to a preferred embodiment of the invention;
FIG. 8 is a continuation of FIG. 7 ;
FIG. 9 is a prior art representation of prior art otherwise statement and implementation;
FIG. 10 is an overview schematic representation of disabling an otherwise term according to a preferred embodiment of the invention;
FIG. 11 is an overview schematic representation illustrating a programmable otherwise (PO) according to a preferred embodiment of the invention;
FIG. 12 is an overview representation illustrating a combination of PPT and PO according to a preferred embodiment of the invention;
FIG. 13 is an overview representation illustrating the inputs/outputs of the circuit used in a combined PPT/PO-circuit according to a preferred embodiment of the invention;
FIG. 14 is a schematic representation showing the connection of the PPT/PO-circuit to the FSM, according to a preferred embodiment of the invention;
FIG. 15 is a schematic representation illustrating an alternative using a repair CAM according to a further preferred embodiment of the invention;
FIG. 16 shows a further inventive, alternative embodiment using a repair RAM;
FIG. 17 shows details of FIG. 16 ;
FIG. 18 shows further details of FIG. 16 .
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 , the general form of a prior art Finite State machine is depicted with a number of i inputs, o outputs, s state signals and s next state signals.
With general reference to the figures and with special reference now to FIGS. 2 and 3 the usual FSM description using state table is shortly introduced, as this mode of description is also used for the present invention.
State Machines are either drawn as state diagrams or are represented using state tables. In the following, state table representations are used to illustrate the ideas. Although the presentation assumes that combinational functions are represented in the sum of products form (disjunctive Normal form), however, the same ideas could be easily applied if combinational functions are represented in the product of sums form (conjunctive Normal form) or in any multilevel representation.
In FIG. 2 an extract of a FSM using a state table description is shown. In the first column the current state is shown, in the next two columns the input and the output vector are shown, and in the fourth column the next state is shown. In the example given there are 3 input signals and 2 output signals. A ‘0’ in the input vector column represents that the input signal must be used in the inverted form, a ‘1’ represents that the input signal must be used in it's true form and a ‘.’ represents that this input signal is don't care. Similarly, a ‘0’ for an output signal means that the output must be low, a ‘1’ indicates that the output must be high, and a ‘.’ represents that the value is “don't care” for the corresponding state input vector combination.
In FIG. 3 the prior art relationship between a row in the state table and the corresponding product term (e.g. row 3 and product term Sm_pt 3 ) and one output signal (e.g. o 1 ) and the corresponding sum of products is shown. Every row in the state table represents a product term. It should be noted that combinational functions can be represented as a sum of product terms. To ease the description it is assumed without loss of generality that there exists a state decoder, which generates for each state Sm of the FSM a corresponding signal Sm_Dec, which gets active if and only if the FSM is in state Sm. The inputs of each product term are then a state decode signal Sm_Dec, and the relevant input signals representing a row in the state table. E.g.: Sm_pt 3 would be fed by the state decode signal Sm_dec and the input signals I 1 (in inverted form) and I 3 . I 2 is don't care and therefore not fed into this product term.
For a given output function those product terms are summed-up in an OR gate 36 , if there is a ‘1’ in the output of the corresponding row in the state table. Thus, only product terms Sm_pt 1 and Sm_pt 3 are fed into OR gate 36 .
With reference to FIG. 4 , the basic inventional approach is illustrated, i.e., to
a) deactivate - 40 -, i.e., to disable a product term and/or to b) activate - 42 - or - 44 - a programmable product term.
With reference to FIG. 5 , the above-mentioned measure a) is preferably done by adding an “Enable means” for every product term. Preferably, this is a shift-only latch 50 , the output of which is connected to an AND gate 52 , the input signals of which further comprises the signal lines associated with the state decode Sm_Dec and the respective input vector (I 1 , I 2 , I 3 ), as this was basically shown and described above with reference to FIG. 3 . When switched to “OFF”, a product term is disabled, as a ‘0’ is output from the AND gate 52 and fed as an input into the OR gate 36 , see FIG. 3 . When switched to “ON” a term is enabled (which is the default case). This approach can be done as long as the number of terms is quite small, as e.g., up to a plurality of about 15 to 30 product terms which are envisaged to be reprogrammable. For higher number of product terms an alternative, preferred implementation is provided by the present invention, as illustrated next with reference to FIG. 6 .
A predetermined set of j programmable “Disable Registers” 60 A, . . . 60 E are connected to a respective number of decoders 62 A, . . . 62 E. Each decoder generates n decode signals, where n represents the number of product terms of the machine. Each Decode signal Disable_Pt_k is fed into a NOR gate 64 .
The output of said NOR gate 64 is fed to an AND gate 52 , the function of which was already described above in FIG. 5 description.
An example is assumed, in which a number of n=256 product terms exist. Thus, 8 bits are necessary to code said number of 256 product terms. The decoder 62 A, . . . 62 E decodes which product term was written into the respective disable register 60 A, . . . 60 E, and the respective decoder signal gets active.
Thus, a particular product term is identified by said decoder output signal and can be treated as it was described before. In case, product term PT 7 and product term PT 19 must be corrected, the value 7 would be written into register 60 A and the value 19 into register 60 E. The NOR gate 64 would get an active Disable_PT_ 7 from decoder 62 A. All other inputs to NOR gate 64 would be inactive. NOR Gate 64 would thus disable the product term. The decoder 62 E would activate Disable_PT_ 17 , which would feed the corresponding NOR Gate for product term 17 (not shown).
The number of j=5 disable registers is provided to disable up to j=5 product terms, which are to be deactivated according to the invention. The number of j=5 is exemplary only, and can be adapted to the specific experience a chip producer has, saying a given state machine shows in 99% of all cases no more than j=5 wrong product terms. Thus, in such situation, 99% of cases can be covered and can be corrected according to the invention. In many cases, a number of j=2 disable registers is sufficient per FSM.
Next, with reference to FIG. 7 it will be described how a programmable product term can be generated according to an inventive embodiment. In a generalized product term it must be possible to ‘connect’ each state decode and each input signal in either true or inverted form to the AND-gate. Also it must be possible that Don't care input signals are not ‘connected’ at all to the AND-gate. ‘Connect’ is meant from a logical point of view. In the following, the circuit means to implement those ‘connections’ will be described.
The facilities required are an Input Mask Register 70 , an Input Compare Register 71 , and a State Compare Register 72 with respective post-connected circuit comprising an AND gate 75 , a compare logic 76 and 77 . A post-connected AND gate 78 is provided for determining that a particular state is present, together with a particular input vector setting, as described above.
It should be noted that the AND gate 75 exists in vectorized form (i instances). These AND gates generate a modified Input Vector in which all input signals, which are don't care, are inactive. This is achieved thru the setup of the Input Mask register. Each bit in this register, for which the corresponding input is either a ‘1’ or a ‘0’ in the state table is set to ‘1’. All bits in the register for which the corresponding input is a don't care in the state table, are set to 0.
The resulting modified input vector is now compared with the value in the Input Compare (Cmp) Register in the CMP 76 logic. The CMP logic 76 generates a True output if and only if both input vectors fed to it are bit for bit identical. The bits in the Input Cmp register are setup such that for each ‘1’ in the input vector in the state table the corresponding bit in the Input Cmp register is set to a ‘1’ also. All other bits are set to ‘0’.
In a similar way the s bits of the current state vector are compared in a CMP circuit 77 with a State Cmp Register. The output of the CMP circuit 77 gets active, if and only if those two vectors are identical. Therefore this output represents a state decode. The outputs of the CMP circuit 76 and 77 are fed into an AND circuit 78 , which produces a product term. Since this form of a product term can realize any kind of product term possible in the FSM, it is called a generalized product term (GPT). Thru programming of the registers in FIG. 7 the GPT gets personalized.
In order to effect output signals (next state signals) this GPT must be ‘connected’ to some of the OR gates implementing the output (next state) functions. This is achieved with the means of FIG. 8 .
An output register is needed in which each bit defines if the GPT has an effect (logical connected) to the output signal or not. If the GPT should activate output k, then the corresponding bit in the output register 73 must be set to 1. The output of AND gate 79 gets active, which in turn activates output k. If bit k in the output register is 0, then the AND gate 79 is inactive; the GPT has no effect on output k. For each output signal an individual latch and AND gate 79 is required. The same holds for the next state signals.
The logic circuit comprised of the GPT, the output register and the next state register is called a “programmable product term” (PPT). This is shown in FIG. 8 a . Thru personalization of the output and/or the next state register in the PPT any output/next state signal can be modified if the GPT get active.
In short, a GPT is a general form of a Boolean function of a product term. The PPT activates the ‘wires’ from the GPT to the output/next state signals. In the default state the PPT is inactive, the output and next state registers are loaded with zeros. This means effectively that there is no ‘wire’ from the GPT to any output/next state signal.
Thus, as reveals from the above, a product term can be disabled, and a new exchangeable, free programmable product term may be activated, instead, in order to “repair” errors in the silicon of the FSM.
A preferred additional feature of the present invention consists in disabling and adding a new, correct, ie, “repairing” so-called “Otherwise”-term.
An important design element in a prior art state table-based designer toolbox is the so-called “OTHERWISE” expression. This design element is provided by most state-of-the-art development tools and is thus advantageous to be able to be implemented in a form which is also able to be repaired, if necessary. This circuitry allows to succinctly identify the rest of all precisely defined states and input settings—in FIG. 9 exemplarily depicted as Sm_PT_ 1 , Sm_Pt_ 2 , and Sm_Pt_ 3 . This “logic “OTHERWISE” rest” can then be implemented in a well defined path of the FSM, thus providing a consistent logic behavior without “gaps”.
FIG. 9 , which expresses state-of-the-art circuitry—shows the state table syntax in the above part, and the circuit implementation in the bottom part. What reveals from the bottom part of the drawing is that a NOR gate 90 is fed with said signals Sm_PT_ 1 , Sm_Pt_ 2 , and Sm_Pt_ 3 . When none of them is TRUE, then the NOR gate 90 generates a TRUE control signal at its output meaning that the OTHERWISE case is present. This control signal is added with the Sm_Dec signal, decoding a given particular, exemplary state Sm, in AND gate 92 . To implement partial programmability for FSMs using Otherwise the following tasks must be solved:
An ‘erroneous’ Otherwise term must be disabled; If an additional state transition is required for a state (a PPT is activated for that state), then the Otherwise term for that state must be modified.
If a state was implemented without an Otherwise term and an Otherwise term is needed after silicon was built, then the capability to activate a programmable Otherwise for that state must be provided.
FIG. 10 illustrates, how a hardwired OTHERWISE term must be augmented in a partly programmable FSM. The first element is an “Ena_Otherwise” latch 94 , which allows to completely deactivate the Otherwise function, similar to the latch used in FIG. 5 . The next change is required for NOR gate 90 . If in FIG. 10 , row 4 is added to the FSM, then a PPT must be personalized such that a product term for this new row 4 gets active. Obviously the corresponding GPT_Active signal of that PPT must be connected to NOR gate 90 . Since it is not known at the time the silicon is produced, which PPT implements which additional state transition functions, all GPT_Active signals of all PPTs must be connected to NOR gate 90 .
It should be noted that the GPT_ACTIVE signals of activated PPTs, which do not belong to state Sm, do not change the behavior of the Sm_Otherwise signal, even if they are fed as inputs into NOR gate 90 . This is due to the influence of the state decode signal (e.g. Sm_Dec) of AND gate 92 and the state decode signals fed into AND gate 78 (FIG. 7 ). If the PPTs belong to different states then those state decodes are never active at the same time.
With reference to FIG. 11 a preferred implementation of a programmable “otherwise” circuit is shown. Such a programmable otherwise is needed, if in the ‘original’ transition no Otherwise statement existed for state Sm.
As in FIG. 7 a state compare register 110 and a CMP logic 113 is provided, which is fed by the current state and by the State CMP register. The current state Sm is used also to control a multiplexer 111 such that the multiplexer 111 drives the value of the Sm_No_PT_Active input to the output. At the output of AND gate 114 the signal Sm_Otherwise gets active, if and only if the current state is Sm and no product term for state Sm is active. The signal Sm_Otherwise is then used in a similar way as the GPT_ACTIVE signal in a PPT to modify the output vector and next state vector bits via the output register 116 , 117 and the AND gates 118 , 119 .
FIG. 12 illustrates a combination circuitry for Programmable Product Terms (PPT) and Programmable Otherwise (PO).
The circuitry required for combining PPT and PO easily is achieved by simply making a superposition of the PPT and the PO circuitry. A simple latch and a multiplexer are needed to activate either function. For the details it can thus be made reference back to the above description and respective drawings.
FIG. 13 is an overview representation illustrating the various inputs and outputs of a combination circuit including PPT and PO facility according to FIG. 12 . Inputs are Input vector and current state vector, and a plurality of control signals Si_No_PT_active saying that for a state Si no product term is active.
Output is the respective output vector for the current state and the next state, as well as a GPT_Active control signal obtained from the output of AND gate 78 , see back to FIG. 7 .
FIG. 14 serves as an overview illustration of the connection of the inventive PPT/PO-circuit 140 described above to the prior art FSM 142 , according to a preferred embodiment of the invention.
Circuit means 141 are depicted that allow that each hardwired product term can be disabled, and means 140 are depicted that add programmable product terms which allow to add new behavior to the state machine.
Scan-Only SRLs are preferably used to program the required behavior of those programmable product terms. As reveals from the drawing, the inventive circuits can be easily added to prior art logic concepts which are denoted by circle 142 .
With reference to FIG. 15 an alternative solution to the inventive technical problem is disclosed. In this alternative, basically, the same inventive idea is followed, but instead of hardwired logic, which is added in the above-described embodiment to generate new corrected product terms or a new corrected “otherwise”, a Content Addressable Memory (CAM), thus referred to as a Repair-CAM 154 , is introduced. It comprises the corrected output bits required for error-free behavior of the FSM. The control logic required to know, under which circumstances the Repair-CAM is used for generating the corrected output bit values, is basically the same as described before. In so far, reference is made to the above description, where applicable.
In more detail, the state vector 155 and the above mentioned inputs 156 , see FIG. 15 , are used as search arguments into the Repair-CAM 154 . If there is a row in the Repair CAM which matches the search argument, the Repair-CAM supplies the Next State vector and the outputs for the FSM, depicted with “nf” and of”, again.
In order to do that a Multiplexer (MUX)-Select signal 157 is supplied by the Repair CAM, which gets only active if the search argument is found in the Repair-CAM. If said MUX_Select signal 157 is active, the multiplexers 150 and 152 select the outputs of the Repair CAM, via lines 158 , and 159 , respectively. If the MUX_Select signal is inactive, then the correct outputs of the nf and of functions are selected.
The inventive principles can be applied in a broad field of hardware technology. As Content Addressable Memories (CAM) are not available in all technologies, a similar implementation as disclosed above uses the concept of a Repair-RAM instead of a Repair CAM.
With reference to FIG. 16 three basic components are shown. The hardwired FSM, depicted by a broken-line frame 164 with “nf” and “of” areas, further a Repair RAM 160 , which takes over control of the state machine in case the original hardwired machine behaves erroneously, and a RAM address generation+FSM select logic, depicted in block 162 . Said logic 162 controls two multiplexers 150 and 152 , as above, which determine, if the hardwired FSM or the Repair RAM drive the next state and the outputs.
With this structure the density advantage of a RAM compared to the Shift-Register Latches (SRLs) used in programmable product terms could be advantageously taken profit from. In such a structure, if one of the state transitions or outputs of a state has an error, then all the logic associated with that state will be disabled, and the Repair RAM 160 will completely control all the outputs and state transitions belonging to that state. The Repair RAM 160 is preferably organized like a cache in several compartments, and every compartment covers one of the rows belonging to one state. This preferred embodiment is further shown in FIG. 17 .
With reference to FIG. 17 , the Repair RAM 160 is depicted at the bottom part of the drawing. It comprises a predetermined number k of compartments. The number k is determined by the largest number of state transitions in a state; e.g., in FIG. 2 there are defined a number of 3 state transitions for state Sm, and a number of 2 transitions for state Sn. Therefore, k would have to be 3.
Each compartment comprises an Input Mask field 170 , an Input Compare field 172 , a Next State field 174 and an Output field 176 . A Mask and Compare logic 178 is connected to respective ones of above mentioned Inputs and to a respective Input mask field and Input Compare field. The compare logic 178 works basically in the same way as the corresponding logic in the PPT hard wired embodiment mentioned above. Thus, only with some small amount of separately provided logic an “Otherwise” function can be implemented additionally, as well.
FIG. 18 shows the logic block 162 (see FIG. 16 ) details required for the address generation for the Repair-RAM. It selects, which of the state machines, the hardwired, or the Repair-RAM FSM, will drive the outputs for current and the next state.
The Repair RAM Address Generation logic 162 comprises one or a plurality of State Compare Registers 180 , 181 , which are loaded with the value of the particular state, which must be corrected. For every State Compare Register 180 , 181 , a Compare logic 182 , 183 is output-connected, which compares the current state with the value of its respective State Compare Register. If both match, then the Repair RAM must take over control, as it was indicated earlier above.
In particular, via an OR-Gate 184 a “Select-Repair-RAM”-signal gets active which controls the multiplexer in FIG. 16 such, that the Repair-RAM drives outputs and next state signals. Further, the signals from the Compare logic 182 , 183 are fed into a RAM Address Encode logic 185 , which converts the 1 -of-n code of the plurality of n “generate Address of x” i.e., “Gen_Addr_x” signals into a binary encoded address.
Since most of the Finite State Machines are generated by program tools, which use either a state diagram or a state table as an input, there is no time-consuming effort required for a designer to add the new inventive elements. All necessary is to specify of correction circuits, i.e., how many PPTs, or how many additional states in the Repair-RAM case the developer considers to add to his state machine. For all the rest of design work, the prior art FSM design tool takes care. Thus, with a careful choice, which should be a good compromise between additional costs and correction potential, the FSM comprising hardware can be brought quicker and cheaper to market.
While the preferred embodiment of the invention has been illustrated and described herein, it is to be understood that the invention is not limited to the precise construction herein disclosed, and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.
|
A method and respective hardware logic circuit for implementing partially programmable Finite State Machines in the hardware of digital systems which use finite state machines to implement the control logic of the hardware design. In order to provide a partly reprogrammable Finite State Machine (FSM), which can be reprogrammed in a limited way such that no costly new physical re-build of the chip including said FSM is required, a hardwired FSM includes circuit means that allow that each hardwired product term to be disabled, and further includes means that add programmable product terms which allow adding new behavior to the state machine. Scan-Only SRLs are preferably used to program the required behavior of those programmable product terms.
| 6
|
BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates to a simplified phonograph capable of being started by a shock imparted thereto. More particularly, the present invention concerns a device into which the simplified phonograph hereof is incorporated. Even more particularly, the present invention concerns a phonograph which is suitable for being incorporated in a toy, such as a laughing bag or a talking doll, and which is capable of generating sounds when any exterior force or shock is imparted to the toy.
II. Description of the Prior Art
Hitherto, simplified phonographs of shock starting type have been provided. These conventional phonographs, generally, can be classified into two major types. First, there is the phonograph wherein a starting lead switch is correlated with a weight means. The other type of phonograph contemplates a link mechanism which is correlated to a weight means.
The first type of phonographs has proven to be not only of somewhat high cost, due to the fact that it necessitates the use of two switch contacts and a complicated weight means construction, but, also, has a considerably delicate lead switch mechanism. Consequently, the first type of phonograph is unsatisfactory as a simplified phonograph for toys due to malfunctions and low acceptance or yield rate.
In case of the second or other type, the link mechanisms of the device are, by their inherent nature complicated and too big to be received in a small casing. Thus, where used, they not only give rise to a cumbersome appearance, but, also, are ineffective. Most important, though, there is great difficulty in incorporating such phonographs into small size toys.
Yet, the mechanical starting system of the second type does display advantageous features, such as, correct and firm function and low production cost. These advantages are suitable for simplified phonographs of the type under consideration.
SUMMARY OF THE INVENTION
The present invention seeks to house a simplified phonograph having a mechanical starting means in a casing and thereby to provide a device having a compact body.
An object of the present invention is to provide a shock starting device of simple construction and low cost.
Another object of the present invention is to provide a shock starting device which does not limit the scope of appropriate application of the simplified phonograph into which the present starting device is incorporated.
According to the present invention, a shock starting simplified phonograph comprises a weight means and a means correlated with said weight means for lifting a sound transmitting member. The weight means, lifting means and transmitting member are installed in a casing. This enables the outside appearance and size of the phonograph utilizing this invention to be entirely the same as that of an ordinary phonograph. Thus, the application of the device of the present invention is not adversely limited, in any respect.
Further, on account of any exterior action, other than the shock exerted from the outside, there exists no possible chance of the device misstarting.
Lifting up of the sound transmitter of the present invention is performed in a merely mechanical manner, and therefore, the device functions very steadily and can be manufactured at a low cost.
For a more complete understanding of the present invention, reference is made to the following detailed description and accompanying drawing. In the drawing, like reference characters refer to like parts throughout the several views, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side cross-sectional view of the device of the present invention;
FIG. 2 is a cross-sectional view of the device, similar to FIG. 1, but the lifting means being in the lifted position;
FIG. 3 is a partially cut-away top plan view of the device hereof;
FIG. 4 is a top plan view of the present device with the housing removed, and
FIG. 5 is an exploded, perspective view of another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing, and as noted above, FIG. 1 depicts a simplified phonograph in cross-section showing the device hereof in the course of sound reproduction and FIG. 2 is similar to FIG. 1, but shows a tone arm in a return mode toward a starting point or position.
As shown in these figures, a casing 1 of a phonograph comprises a chassis 1a and housing 1b. A turn table 17 is rotatably supported on a base plate of the chassis 1a. A record disc 3 rests on the turn table 17.
A battery magazine 18 houses a battery 19. The battery 19 powers the turn table to effectuate movement thereof.
A motor 2 is vertically mounted on a middle deck or plate of the chassis 1a. The motor 2 includes an output shaft 2a which extends downwardly. The output shaft passes over the middle plate, as shown. The motor 2 has an upper bearing for receiving an upper end of the output shaft. The upper bearing is firmly held in the housing 1b, as shown.
The peripheral side of the output shaft 2a is faced with the peripheral side surface of the turn table 17. An endless belt 20, made of a resilient material, is extended between and around the peripheries of the turn table 17 and the output shaft 2a.
A speaker unit 15 is supported at one end thereof above the middle deck of the chassis 1a by a pair of supporting posts 21. The posts 21 extend upwardly from the middle deck.
The speaker unit 15 comprises a sound transmitting member 13 and a speaker 14. One end portion of the sound transmitting member is configured similarly to a bifurcated yoke (FIG. 4). The end portion of the member 13 is supported on the posts 21 at the tip ends of the two arms of the bifurcated yoke. The end portion of the member 13 is, thus, capable of being swung in an upward and downward direction. As shown in FIGS. 1, 2 and 4, the middle deck of the chassis 1a, also, swingably supports thereon a tone arm 9. A pickup 4, which carries a downwardly directed reproduction stylus 5 is carried on the free end of the tone arm. The stylus 5, as shown, is directed toward the record disc 3.
The middle deck has an oblong aperture 22 formed therein along the locus of the swing motion of the pickup 4, so that the reproduction stylus may engage the record disc 3. The pickup 4 extends downward through the aperture 22 to the upper face of the record disc 3. The tone arm 9 is urged, by means of a return spring 6, laterally toward the starting point of reproduction 7 of the record disc 3 and also upwardly toward the speaker unit 15.
The other end part of portion of the sound transmitter 13 of the speaker unit, opposite the bifurcated end supported by the supporting posts 21, detachably rides on the pickup 4 of the tone arm 9. This urges the top of the pickup 4 downward, conjointly with a stylus force spring 12, to the upper face of the record disc 3.
The pickup 4, also, swingably travels during its sound reproduction while being kept in sliding contact with the lower face of the sound transmitter member 13.
As shown in the drawings, an electric switch 11 breaks the electric circuit, when the pickup 4 reaches the terminal or end point of sound reproduction 10, such that the supply of electricity to the motor 2 is cut off. This stops rotation of the record disc 3.
As shown in FIGS. 1 to 3, the housing 1b comprises a speaker housing 1c. Disposed within and substantially centrally of the housing 1c is a weight means W. The weight means W is suspended from the top face of the speaker house 1c and is swingable about a shaft 23. The shaft 23 is disposed on the lower face of the top plate of the speaker house 1c and projects downward up to the interior space of a cone of the speaker 14.
A bracket 23' for supporting the weight means W thereon is attached concentrically about the shaft 23 for relative rotation therebetween. The bracket is configured as a pair of bifurcated arms, as shown in FIG. 3. A tip end of one of the branched arms of the bracket carries the weight means W. The tip end of the other arm carries a cam piece 24, while the upper rim of the arm constitutes a cam surface.
Both the weight means W and the cam piece 24 take their positions upto the inside of a conical cavity defined by the peripheral wall of the speaker 14.
A projection 25 extends radially and inwardly from the top rim of the side wall of the speaker so as to be laid on the locus of the rotational motion of the cam 24 about the shaft 23.
Both the weight means W and the cam piece 24 are resiliently biased by means of a coil spring 26 assembled about the shaft 23 such that the cam is normally prevented from contacting the projection 25 absent any shock tending to move the projection toward the counter direction against the bias exerted upon the device.
A stopper 27 restrains the cam 24 against the resilient force of the coil spring.
In this embodiment of the invention, the cam 24 and the projection 25 comprise a means for lifting the sound transmitting member 13 through the speaker 14.
The lifting action is performed in an entirely mechanical manner without relying on any electrical means.
When an exterior shock of appropriate extent is imparted to this kind of device, the weight means W will swingably rotate in a direction shown by the dot arrow line (FIG. 3) against the resilient force of the spring 26. Then, the cam piece 24, also, will rotate through the motion of the bracket in the same direction.
The rotation of the cam piece 24, caused by the inertial force of the weight means W, will scoop up the projection 25 of the speaker 14. Then, the speaker 14, together with the sound transmitting member 13, is lifted pivotally and raised about the supporting posts 21 against the resilient force imparted by the stylus force spring 12. Thus, the pickup 4 is released from the stylus force given by the spring 12.
Although the pickup 4 is adjusted to hold the switch 11 "OFF", i.e., opened at the terminal point 10 of sound reproduction, the reproduction stylus 5, upon removal of the stylus force, will move upward away from the engagement with the record groove. Then, the pickup 4 will move laterally, by means of the return spring 6, in a direction toward the starting point 7 of sound reproduction. Next, the switch 11 will be closed, since there is no restraining force given by the pickup 4 to keep the two contact blades away from each other. Thus, electricity is supplied to the motor 2 so as to rotate the turn table 17 and record disc 3 carried thereon.
Since the weight means W is always resiliently urged in the same direction by the spring 26, the weight means W and the cam 24 will move back to their initial position where they were positioned before the shock was applied to the device. Consequently, the projection 25 is released from the upward lifting force of the cam piece 24, which, in turn, causes descent of the speaker 14 and the sound transmitter 13 under the downward resilient force of the spring 12 to impart necessary stylus force.
Hence, it becomes possible for the pickup 4 to be imparted with the necessary stylus force at the starting point 7 of sound reproduction and the reproduction stylus 5 is able to engage the recording groove.
In this manner, the starting of sound reproduction can be effected by application of a certain extent of shock to the device.
FIG. 5 shows another embodiment of the present invention, wherein a weight means W is swingably mounted on an upper surface of the battery magazine 18.
According to this embodiment, a speaker unit 15 is situated so as to extend over the portion wherein the locus of swing motion of the weight means W is entirely encompassed. The weight means W has, as an integral part thereof, within its locus of swing, an upwardly facing cam surface 24'.
The speaker unit 15 has a downwardly projected portion 14' which at its lower peripheral marginal rim, faces and engages the cam surface 24' such that the cam surface 24' may push up the projected portion 14', when the weight means W is swung in a direction as shown by a dot arrow line in the drawing.
In this manner, the speaker unit 15 is lifted by the movement of the weight means W due to the inertia caused by an applied shock. When the shock occurs the pickup 4 is released from the needle pressure which has been applied thereto.
Other constructions and functions of the device of this embodiment, such as spring 26 attached to the weight means W and so on, are entirely similar in principle to those of the aforesaid embodiment, so further explanation will not be repeated.
In the present embodiment, both the cam surface 24' and the protruding portion 14' at the lower peripheral rim of the speaker constitute the lifting means 16.
|
A weight means disposed in a casing of a phonograph is capable of being swung and urged normally in a predetermined direction. The weight means is associated with a lifting means. The lifting means is able to mechanically lift a sound transmitting member to move it in a direction away from a record disc against which, said transmitting member is urged under stylus force by means of a stylus force spring.
According to this simple and correct mechanism, the stylus force exerted on the sound transmitting member is released by means of a shock without fail. Hence, a pickup will return to a starting point of sound reproduction by a return spring. The weight means is then able to return to its original location so that the necessary stylus force may be imparted again to the pickup through the sound transmitting member.
| 6
|
TECHNICAL FIELD
The present invention relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides a downhole electrical power generator.
BACKGROUND
A wide variety of downhole well tools may be utilized which are electrically powered. For example, flow control devices, sensors, samplers, packers, instrumentation within well tools, telemetry devices, etc. are available, and others may be developed in the future, which use electricity in performing their respective functions.
In the past, the most common methods of supplying electrical power to well tools were use of batteries and electrical lines extending to a remote location, such as the earth's surface. Unfortunately, some batteries cannot operate for an extended period of time at downhole temperatures, and those that can must still be replaced periodically. Electrical lines extending for long distances can interfere with flow or access if they are positioned within a tubing string, and they can be damaged if they are positioned inside or outside of the tubing string.
Therefore, it may be seen that it would be very beneficial to be able to generate electrical power downhole, e.g., in relatively close proximity to a well tool which consumes the electrical power. This would preferably eliminate the need for batteries, or at least provide a means of charging the batteries downhole, and would preferably eliminate the need for transmitting electrical power over long distances.
SUMMARY
In carrying out the principles of the present invention, a downhole electrical power generator is provided which solves at least one problem in the art. An example is described below in which flow through a tubular string is used to vibrate a flow restricting device, thereby displacing magnets relative to one or more electrical coils.
In one aspect of the invention, a downhole electrical power generating system is provided which includes a flow restricting device for variably restricting flow through an opening. The restricting device vibrates in response to flow through the opening, with the restricting device thereby alternately increasing and decreasing flow through the opening. An electricity generating device generates electricity in response to vibration of the restricting device.
In another aspect of the invention, a downhole electrical power generating system is provided which includes a flow restricting device which vibrates in response to flow through an opening, thereby alternately increasing and decreasing flow through the opening. A pressure differential across the restricting device variably biases the restricting device to increasingly restrict flow through the opening. The pressure differential alternately increases and decreases in response to respective alternate increasing and decreasing flow through the opening. An electricity generating device generates electricity in response to vibration of the restricting device.
These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic partially cross-sectional view of a downhole electrical power generating system embodying principles of the present invention; and
FIG. 2 is an enlarged scale schematic cross-sectional view of an electrical power generator which may be used in the system of FIG. 1 .
DETAILED DESCRIPTION
Representatively illustrated in FIG. 1 is a downhole electrical power generating system 10 which embodies principles of the present invention. In the following description of the system 10 and other apparatus and methods described herein, directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present invention. The embodiments are described merely as examples of useful applications of the principles of the invention, which is not limited to any specific details of these embodiments.
As depicted in FIG. 1 , a tubular string 12 (such as a production, injection, drill, test or coiled tubing string) has been installed in a wellbore 14 . An electrical power generator 16 is interconnected in the tubular string 12 . The generator 16 generates electrical power from flow of fluid (represented by arrow 18 ) through an internal flow passage 20 of the tubular string 12 .
The fluid 18 is shown in FIG. 1 as flowing upwardly through the tubular string 12 (as if the fluid is being produced), but it should be clearly understood that a particular direction of flow is not necessary in keeping with the principles of the invention. The fluid 18 could flow downwardly (as if being injected) or in any other direction. Furthermore, the fluid 18 could flow through other passages (such as an annulus 22 formed radially between the tubular string 12 and the wellbore 14 ) to generate electricity, if desired.
The generator 16 is illustrated in FIG. 1 as being electrically connected to various well tools 24 , 26 , 28 via lines 30 external to the tubular string 12 . These lines 30 could instead, or in addition, be positioned within the tubular string 12 or in a sidewall of the tubular string. As another alternative, the well tools 24 , 26 , 28 (or any combination of them) could be integrally formed with the generator 16 , for example, so that the lines 30 may not be used at all, or the lines could be integral to the construction of the generator and well tool(s).
The well tool 24 is depicted in FIG. 1 as being an electrically set packer. For example, electrical power supplied via the lines 30 could be used to initiate burning of a propellant to generate pressure to set the packer, or the electrical power could be used to operate a valve to control application of pressure to a setting mechanism, etc.
The well tool 26 could be any type of well tool, such as a sensor, flow control device, sampler, telemetry device, etc. The well tool 26 could also be representative of instrumentation for another well tool, such as a control module, actuator, etc. for operating another well tool. As another alternative, the well tool 26 could be one or more batteries used to store electrical power for operating other well tools.
The well tool 28 is depicted in FIG. 1 as being a flow control device, such as a sliding sleeve valve or variable choke. The well tool 28 is used to control flow between the passage 20 and the annulus 22 . Alternatively, the well tool 28 could be a flow control device which controls flow in the passage 20 , such as a safety valve.
Although certain types of well tools 24 , 26 , 28 are described above as being operated using electrical power generated by the generator 16 , it should be clearly understood that the invention is not limited to use of the generator 16 with any particular type of well tool. The invention is also not limited to any particular type of well installation or configuration.
Referring additionally now to FIG. 2 an enlarged scale schematic cross-sectional view of the generator 16 is representatively illustrated. The generator 16 is shown apart from the remainder of the system 10 , it being understood that in use the generator would preferably be interconnected in the tubular string 12 at upper and lower end connections 32 , 34 so that the passage 20 extends through the generator.
Accordingly, in the system 10 the fluid 18 flows upwardly through the passage 20 in the generator 16 . The fluid 18 could flow in another direction (such as downwardly through the passage 20 , etc.) if the generator 16 is used in another system.
The passage 20 extends through a generally tubular housing 36 of the generator 16 . The housing 36 may be a single tubular member or it may be an assembly of separate components.
Note that the housing 36 includes a flow diverter 38 in the form of a venturi in the passage 20 . As the fluid 18 flows through the diverter 38 , a pressure differential is created, in a manner well understood by those skilled in the art. Pressure in the passage 20 upstream of the diverter 38 will, therefore, be greater than pressure downstream of the diverter.
The housing 36 also includes openings 40 formed through its sidewall downstream of the diverter 38 , and openings 42 formed through its sidewall upstream of the restriction. An annulus 44 formed between the housing 36 and an outer housing 46 is in communication with each of the openings 40 , 42 . Thus, instead of flowing directly through the diverter 38 , a portion of the fluid 18 is induced by the pressure differential in the passage 20 to flow through the openings 42 upstream of the diverter 38 to the chamber 44 , and from the chamber through the openings 40 back into the passage 20 downstream of the diverter.
Note that it is not necessary for the diverter 38 to include a restriction in the passage 20 in order to divert the portion of the fluid 18 to flow through the annulus 44 . For example, the diverter 38 could instead include an enlarged flow area (such as, provided by an annular recess) in the passage 20 at the openings 40 , so that a pressure reduction is created in the annulus 44 via the openings 40 , thereby drawing fluid into the chamber from the passage via the openings 42 upstream of the enlarged flow area. In this manner, the pressure differential may be created in the passage 20 without restricting flow or access through the passage.
A flow restricting device 48 is positioned in the chamber 44 . The device 48 operates to variably restrict flow through the openings 40 , for example, by varying an unobstructed flow area through the openings. The device 48 is illustrated as a sleeve, but other configurations, such as needles, cages, plugs, etc., could be used in keeping with the principles of the invention.
As depicted in FIG. 2 , the openings 40 are fully open, permitting relatively unobstructed flow through the openings. If, however, the device 48 is displaced upwardly, the flow area through the openings 40 will be increasingly obstructed, thereby increasingly restricting flow through the openings.
The device 48 has an outwardly extending annular projection 50 formed thereon which restricts flow through the chamber 44 . Because of this restriction, another pressure differential is created in the chamber 44 between upstream and downstream sides of the projection 50 . As the fluid 18 flows through the chamber 44 , the pressure differential across the projection 50 biases the device 48 in an upward direction, that is, in a direction which operates to increasingly restrict flow through the openings 40 .
Upward displacement of the device 48 is resisted by a biasing device 52 , such as a coil spring, gas charge, etc. The biasing device 52 applies a downwardly directed biasing force to the device 48 , that is, in a direction which operates to decreasingly restrict flow through the openings 40 .
If the force applied to the device 48 due to the pressure differential across the projection 50 exceeds the biasing force applied by the biasing device 52 , the device 48 will displace upward and increasingly restrict flow through the openings 40 . If the biasing force applied by the biasing device 52 to the device 48 exceeds the force due to the pressure differential across the projection 50 , the device 48 will displace downward and decreasingly restrict flow through the openings 40 .
Note that if flow through the openings 40 is increasingly restricted, then the pressure differential across the projection 50 will decrease and less upward force will be applied to the device 48 . If flow through the openings is less restricted, then the pressure differential across the projection 50 will increase and more upward force will be applied to the device 48 .
Thus, as the device 48 displaces upward, flow through the openings 40 is further restricted, but less upward force is applied to the device. As the device 48 displaces downward, flow through the openings 40 is less restricted, but more upward force is applied to the device. Preferably, this alternating of increasing and decreasing forces applied to the device 48 causes a vibratory up and down displacement of the device relative to the housing 36 .
An electrical power generating device 54 uses this vibratory displacement of the device 48 to generate electricity. As depicted in FIG. 2 , the generating device 54 includes a stack of annular shaped permanent magnets 56 carried on the device 48 , and a coil 58 carried on the housing 36 .
Of course, these positions of the magnets 56 and coil 58 could be reversed, and other types of generating devices may be used in keeping with the principles of the invention. For example, any of the generating devices described in U.S. Pat. No. 6,504,258, in U.S. published application no. 2002/0096887, or in U.S. application Ser. Nos. 10/826,952 10/825,350 and 10/658,899 could be used in place of the generating device 54 . The entire disclosures of the above-mentioned patent and pending applications are incorporated herein by this reference.
It will be readily appreciated by those skilled in the art that as the magnets 56 displace relative to the coil 58 electrical power is generated in the coil. Since the device 48 displaces alternately upward and downward relative to the housing 36 , alternating polarities of electrical power are generated in the coil 58 and, thus, the generating device 54 produces alternating current. This alternating current may be converted to direct current, if desired, using techniques well known to those skilled in the art.
Note that the generator 16 could be used to produce electrical power even if the fluid 18 were to flow downwardly through the passage 20 , for example, by inverting the generator in the tubular string 12 . Thus, the invention is not limited to the specific configuration of the generator 16 described above.
It may be desirable to be able to regulate the vibration of the device 48 , or to stop displacement of the device altogether. For example, damage to the generating device 54 might be prevented, or its longevity may be improved, by limiting the amplitude and/or frequency of the vibratory displacement of the device 48 . For this purpose, the generating device 54 may include one or more additional coils or dampening devices 60 , 62 which may be energized with electrical power to vary the amplitude and/or frequency of displacement of the device 48 .
The electrical power to energize the dampening devices 60 , 62 may have been previously produced by the generating device 54 and stored in batteries or another storage device (not shown in FIG. 2 ). When energized, magnetic fields produced by the dampening devices 60 , 62 can dampen the vibratory displacement of the device 48 and, if strong enough, even prevent such displacement.
Note that, instead of the annulus 44 being formed between the housing 36 and outer housing 46 , the annulus 44 could be the annulus 22 , in which case the outer housing 46 may not be used at all. Thus, the portion of the fluid 18 could be diverted from the passage 20 to the annulus 22 via the openings 42 , and then return to the passage via the openings 40 . As another alternative, the fluid 18 could flow from the annulus 22 into the passage 20 via the openings 40 , without first being diverted from the passage to the annulus via the openings 42 . In this alternative, the diverter 38 , openings 42 and outer housing 46 would not be used, and the device 48 would create a pressure differential in the annulus 22 due to the fluid 18 flowing past the projection 50 in the annulus.
Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the invention, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to the specific embodiments, and such changes are contemplated by the principles of the present invention. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents.
|
A downhole electrical power generator. A downhole electrical power generating system includes a flow restricting device which variably restricts flow through an opening, the restricting device vibrating in response to flow through the opening and the restricting device thereby alternately increasing and decreasing flow through the opening; and an electricity generating device which generates electricity in response to vibration of the restricting device. Another downhole electrical power generating system includes a flow restricting device which vibrates in response to flow through an opening, the restricting device thereby alternately increasing and decreasing flow through the opening, a pressure differential across the restricting device variably biasing the restricting device to increasingly restrict flow through the opening, and the pressure differential alternately increasing and decreasing in response to respective alternate increasing and decreasing flow through the opening; and an electricity generating device which generates electricity in response to vibration of the restricting device.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device for propelling a pipe from a vertical shaft, and more particularly, to a device for exerting propelling power to small bore pipes such as water supply and drainage pipes, gas pipes and cable laying pipes to force them into the ground from the vertical shaft.
2. Description of the Prior Art
Conventionally, a plurality of hydraulic jacks are used for a device for propelling pipes from vertical shafts. The respective hydraulic jacks forming a propelling device are provided to contact on one end a reacting shaft wall of the vertical shaft and on the other end the end of the pipe. The pipe in the vertical shaft is forced into the ground by the operation of the hydraulic jack.
Now, when one operative stroke of the hydraulic jack is made equal to or longer than the length of the pipe, the pipe can be forced from the interior to the exterior of the vertical shaft by only one operation of the hydraulic jack. On the other hand, since the length of the hydraulic jack has to be equal to or longer than that of the pipe, the size of the shaft, i.e., the distance between the reacting shaft wall and the shaft wall surface opposed thereto must be at least 2 times the length of the pipe.
Thus, a problem is encountered in a lot of labor and cost needed for forming the vertical shaft.
On the other hand, when one operative stroke of the hydraulic jack is shorter than the length of the pipe, the size of the vertical shaft can be made less than that in the case of said jack having the operative stroke equal to or longer than the length of the pipe. In this case, however, the pipe cannot be forced into the ground unless a strut is interposed between the pipe and the hydraulic jack. That is, the pipe must be propelled through said strut by extending a rod of the hydraulic jack to force a portion of the pipe into the ground and then withdraw the rod so that said strut is disposed between the pipe end and the rod end of each hydraulic jack to operate again the hydraulic jack. Depending upon the size of said operative stroke must be further reciprocated the rod and added another strut to force the pipe into the ground.
Thus, though the labor and cost needed for forming the vertical shaft can be reduced, troublesome operations such as arrangement of a plurality of struts are added conversely. The efficiency of operation is then obliged to be degraded.
Also, a plurality of said conventional hydraulic jacks are arranged in the form of a box spaced from each other in the circumferential direction of the pipe between the pipe to be propelled and the reacting shaft wall. Thus, measuring instruments such as a propelling error measuring instrument applying laser to the measurement cannot be installed and operated on the pipe axis between the jacks so that troubles take place in measuring the propelling direction of the pipes sequentially forced into the ground to present problems that the operative space in the vertical shaft is narrowed or the vertical shaft must be expanded.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to overcome said conventional problems. That is, the present invention aims to enable pipes to be propelled from a small-dimensioned vertical shaft without interposing any struts while providing a sufficient operative space within the vertical shaft.
A pipe propelling device according to the present invention comprises fundamentally two sets of jack assemblies supported spaced from each other in the vertical shaft and extending laterally of said vertical shaft, each jack assembly comprising a plurality of first stage jacks having a rod end contacting said reacting shaft wall and at least one second stage jack having cylinders connected to the respective cylinders of the first stage jacks and directing the rod end forward in the direction of propelling said pipe.
According to the present invention, the total length of the jack assembly prior to the propulsion of pipe can be minimized while the operative stroke of the jack assembly can be made longer than the length of the pipe by extending operatively said first and second stage jacks.
Accordingly, the size of the vertical shaft can be minimized and further the pipe can be forced entirely into the ground by one operation of the jack assembly without interposing the strut, thereby the efficiency of operation can be remarkably improved.
Further, the present device is made of two sets of jack assemblies spaced from each other, and portions at which the pipes to be propelled against the respective jack assemblies are limited only to the rod end of the second stage jack so that the jacks are not arranged in the form of a box like prior ones. Thus, an instrument for measuring the direction of propelling the pipe forced into the ground can be disposed easily between the jack assemblies or rods.
Also, a gap between the rod end of the second stage jack and the reacting shaft wall can be lessened by locating the front end of said first stage jack in front of the rod end of said second stage jack when all said jacks are under the contracted condition. Consequently, the pipe prior to the propulsion can be arranged closer toward said reacting shaft wall and thus the lateral length of the vertical shaft can be set shorter.
Further, only one first stage jack can be formed with a port connected directly to a pressurized liquid supply source by interconnecting liquid chambers for extruding and returning the first stage jack and liquid chambers for extruding and returning the second stage jack respectively through pressurized liquid pipe paths. Thus, compared with the case in which ports communicating to the pressurized liquid supply source are provided in the respective jacks, the number of pipings can be lessened, and damages due to mutual friction of the pipings can be prevented. Since the cylinders of the first and second stage jacks are interconnected, the first and second stage jack cylinders are moved always integrally with each other. Thereby, no friction takes place between the pipings for these cylinders.
Further, by disposing a push ring connected to the second stage jack to be pivoted about said jack can be adjusted the moving speed of both jacks in the contracting operation of the second stage jack forming a part of each assembly to be approximately equal to each other.
The other objects and features of the present invention will become apparent from the following description of a preferred embodiment of the invention with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view showing a pipe propelling device according to the present invention;
FIG. 2 is a left side view showing the pipe propelling device under the completely contracted condition;
FIG. 3 is a left side view showing the pipe propelling device under the extended condition; and
FIG. 4 is a longitudinal sectional view of the pipe propelling device as viewed from the side, showing schematically a pressurized liquid pipe path.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a pipe propelling device 10 according to the present invention comprises two sets of jack assemblies 12, 14 spaced from each other in a vertical shaft and extending laterally (in the direction of propelling the pipe) of the vertical shaft. Both jack assemblies are slidably mounted on a pair of frames 16 disposed on the bottom of the vertical shaft and extending laterally. The frames 16 are made of H-type steel and interconnected by a plurality of connecting members 18 made of H-type steel arranged longitudinally spaced from each other. Also, the frames 16 are on the rear ends fixed by bolts to a box-like reacting support 20 fixed to the reacting shaft wall of the vertical shaft (see FIGS. 2 and 3).
As shown in FIGS. 1 to 3, each jack assembly comprises a pair of first stage jacks 22, 24 arranged spaced from each other vertically and a second stage jack 26 disposed between the first stage jacks, said first and second stage jacks being interconnected by connecting means 28. The first stage jacks 22, 24 have the same operative stroke and total length.
The first stage jacks 22, 24 have respectively the rod ends 22a, 24a connected to the reacting support 20, and a rod end 26a of the second stage jack 26 are directed forward in the direction of propulsion. Further, a cylinder 26b of the second stage jack extends through the reacting support 20 from the front portion to the rear portion. Thus, the front ends of the cylinders 22b, 24b of the first stage jacks are arranged to be located in front of the rod end 26a of the second stage jack so that a gap between said reacting shaft wall and the rod end 26a of the second stage jack can be lessened, compared with the case of arranging said front ends reversely, provided the second stage jack 26, when subjected to extending operation, needs to be able to extend the rod end 26a forward more than the front ends of cylinders 22b, 24b of the first stage jacks. By such an arrangement, a pipe 30 disposed in front of the rod end 26a to be propelled can be located nearer said reacting shaft wall, and thus the lateral length of the vertical shaft can be set small. In consideration of this point of view, the total length of the second stage jack under the completely contracted condition is preferably shorter than that of the first stage jack under the completely contracted condition. Further, by providing the multiple stage jack like the embodiment shown in the drawings, the second stage jack 26 can be obtained the short total length under the contracted condition, but the large operative stroke.
The connecting means 28 comprises steel blocks 28a, 28b in which the cylinders 22b, 24b of the first stage jacks 22, 24 fit firmly and a steel block 28c in which the cylinder 26b of the second stage jack 26 fits firmly. The blocks 28a, 28c and 28b, 28c are respectively fixed to each other by a plurality of bolts 31, and further between the respective blocks are arranged keys 32 to prevent positively slippage between the first and second stage jacks.
Further, a plurality of pairs other than one pair of the first stage jacks in each jack assembly may be provided and the quantity of the second stage jack may be at least one, provided it is preferable that to give stable thrust to the pipe 30 and propel the pipe 30 efficiently, the respective first stage jacks have the equal capacity, i.e., produced thrust and further the sum of these capacities is equal to the capacity of the second stage jack or to the sum of these capacities when the second stage jacks are plural.
To the second stage jacks in both jack assemblies is connected a push ring 34 for transmitting thrust to the pipe 30. This push ring 34 is arranged on the connecting member 18 of the frame 16 and mounted slidably on a pair of supports 36 extending laterally. The longitudinal dimension of the push ring is maximized in the intermediate position between two sets of jack assemblies 12, 14 and decreased gradually from said intermediate position toward the respective jack assemblies. Also, the push ring 34 is provided with a hole 38 for passing laser beam or the like to measure the direction of propelling the pipe 30.
For the extruding and returning operations of the respective jacks are provided ports communicating to liquid chambers for the extrusion and return in the cylinders. Though pressurized liquid supply pipes may be connected to the respective ports, it is preferable, as shown in FIG. 4, that the extruding and returning liquid chambers of the first stage jacks 22, 24 are connected respectively to the extruding and returning liquid chambers of the second stage jack 26 through pressurized liquid pipe paths.
Extruding and returning ports corresponding to holes for supplying pressurized liquid are provided in the rod ends 22a of the upper first stage jacks.
The extruding pressurized liquid pipe path is made of a path 44 communicating to an extruding liquid chamber 42 in front of a piston 40 from said extruding port through a rod 39 and the piston 40 of the first stage jack, a conduit 48 communicating to the liquid chamber 42 and an extruding liquid chamber 46 in the inner rear portion of the cylinder 26b of the second stage jack, a path 54 extending from the liquid chamber 46 through a piston portion 50a of a first rod 50 of the second stage jack to communicate to an extruding liquid chamber 52 of the first rod 50, a path 60 extending from the liquid chamber 46 through the piston portion 50a of the first rod, a rod portion 50b communicating to the piston portion and a piston portion 50c communicating to the rod portion and received in a hollow portion of a second rod 56 to communicate to an extruding liquid chamber 58 in front of the piston portion 50c and a conduit 64 communicating to the liquid chamber 46 and an extruding liquid chamber 62 in the inner front portion of the cylinder 24b of the lower first stage jack. Further, referring to said capacity again, the sum of pressure receiving areas of both first stage jack pistons respectively in the extrusion and return is equal to the pressure receiving areas of the piston portions 50a, 50c and rear portion of the second rod 56 of the second stage jack.
When pressurized liquid is supplied to said extruding port through a pressurized liquid supplying conduit 66 connected to a pressurized liquid supply source (not shown), the cylinders 22b, 24b, the first rod 50 and the second rod 56 are simultaneously started to move forward in the propelling direction.
On the other hand, the returning pressurized liquid pipe path is made of a path 70 communicating to a returning liquid chamber 68 behind the piston 40 from said returning port through the rod 39 of the first stage jack, a conduit 74 communicating to the liquid chamber 68 and a returning liquid chamber 72 in the inner front portion of the cylinder 26b of the second stage jack, a path 78 communicating to a returning liquid chamber 76 of the second rod from the liquid chamer 72 through the piston portion 50a and the rod portion 50b of the first rod and a conduit 82 communicating to the liquid chamber 72 and a liquid chamber 80 in the inner rear portion of the cylinder 24b of the lower first stage jack.
When pressurized liquid is supplied to said returning port through a pressurized liquid supplying conduit 84 connected to the pressurized liquid supply source, the cylinders 22b, 24b, the first rod 50 and the second rod 56 are started to move simultaneously backward in the propelling direction.
When said first and second stage jacks are operatively extended and contracted, the connecting means 28 slides on the frame 16 with a pair of lower projecting ends of the block 28b contacting the frame 16, and the push ring 34 and the pipe 30 contacting the push ring on the end slide on the support 36.
Further, the extruding conduits 48, 64 and the returning conduits 74, 82 can be formed to extend respectively through the block 28c, a part of the connecting means 28 for said first and second stage jacks or, as shown in FIG. 4, a path extending through the block 28c may be provided to which said conduit communicates. In either case, since said first and second stage jacks are fixed to each other in these cylinders, each conduit is never affected by the extending and contracting operations. Also, by forming the pressurized liquid pipe path in such a manner, damages of pipings due to friction between pipings are not needed to be taken into consideration.
In the extending and contracting operations of all jacks, particularly in the returning operation of contraction, each jack may not retreat with equal speed due to the fitting condition of a packing for preventing pressurized liquid from leakage, dimensional error or the like. To avoid such a phenomenon as far as possible, the push ring 34 is preferably connected to the second stage jack 26 through a connecting portion 86 to permit pivoting about said jack.
As shown in FIG. 4, the connecting portion 86 comprises a socket 88 provided in the push ring 34 and a slip-out preventing member 92 received in the socket and fixed to a reduced diameter portion 90 of the second stage jack rod end 26a having the outer diameter converging forward in said propelling direction to prevent the reduced diameter portion 90 from slipping out of said socket. The reduced diameter portion 90 is formed on the front end with threads onto which is screwed the nut-like slip-out preventing member 92. Also, the slip-out preventing member 92 is received in a recess 94 communicating to the socket 88, and a slight gap is provided between the wall surface of the recess and the slip-out preventing member 92.
Accordingly, when speed difference between both second stage jacks 26 is produced when said both jacks 26 are contracted backward in the propelling direction after the pipe 30 is propelled, the push ring 34 is allowed to pivot in the reduced diameter portion 90 within the range of the gap between the socket 88 and the reduced diameter portion 90 or between the slip-out preventing member 92 and the wall surface of the recess 94. Thereby, the push ring 34 is inclined and one of the second stage jack rod ends 26a regulates the retreat movement of the other second stage jack rod end 26a so that both rod ends 26a will move with approximately equal speed.
Instead of above-mentioned construction, said connecting portion may be formed such that the socket 88 has the inner diameter converging forward in said propelling direction and the reduced diameter portion 90 has the constant outer diameter.
The connecting portion having such a construction may be also applied between the first stage jack rod ends 22a, 24a and a base member 96 mounted on the reacting support 20 (see FIG. 4).
Thus, when the frame 16 supporting the jack assemblies 12, 14 is not extended straight, but bent slightly irregularly in the lateral or longitudinal direction, the respective jack assemblies during movement can swing as a whole with respect to the reacting support 20 thus said reacting shaft wall. Thereby, damages of the device caused by said irregularity can be prevented and the propulsion of the pipe can be maintained. Also, by applying said connecting portion, compared with a ball joint used in place of that, the shorter axial length of the jack will do, working and mounting are easily carried out and further the number of parts is reduced.
|
A pipe propelling device comprises two sets of jack assemblies spaced from each other and arranged in the direction of propelling the pipe in a vertical shaft having a reacting shaft wall so that the small diameter pipe such as water supply and drainage pipes, gas pipes and cable laying pipes can be propelled from the interior to the exterior of the vertical shaft by the extension of two sets of the jack assemblies. To reduce the dimension of the vertical shaft due to propel the pipe, eliminate the interposition of a strut in propelling the pipe and secure an operative space in the vertical shaft, the jack assemblies comprise a plurality of first stage jacks connected to the reacting shaft wall and at least one second stage jack, a cylinder of the second stage jack being connected to cylinders of the first stage jacks.
| 4
|
FIELD OF THE INVENTION
The present invention relates to a tire with improved resistance to sidewall damage such as splitting or puncture. More particularly, the present invention provides a tire with tread features positioned along the sidewall in a manner that improves the protection of the sidewall against damage when contacting obstacles during operation of the tire.
BACKGROUND OF THE INVENTION
Operating a tire in aggressive environments such as off road conditions provides challenges in protecting the tire from damage. Obstacles such as rocks, trees, and other features provide threats to the tire not only along the tread region but also along the sidewall. While the tread region is designed to be in contact with the ground surface and is therefore constructed from compositions intended for this purpose, the sidewalls are generally not designed to be ground contacting. Instead, the sidewalls of a tire typically include a relatively thin layer of rubber material that covers certain structural elements, such as e.g., the cords of a tire carcass, which extend between and through the sidewalls of the tire. This rubber material is conventionally created from a composition not designed for ground contact but rather for flexibility so that the sidewalls can withstand the repeated flexing of the tire that occurs as it rotates through the contact patch. In addition, this sidewall rubber is typically not as thick as the tread rubber. As such, the sidewalls generally have less resistance than the tread to splitting or other puncture damage that can occur when the tire is contacted with an obstacle along the ground surface.
Certain tires are intended for more rugged applications where encounters with obstacles that may split or otherwise damage the sidewall can be frequent. For example, for recreational and emergency off-road applications, tires may be subjected to repeated contact with obstacles that can split the sidewall and damage or even deflate a pneumatic tire. Of course, for such tires, it is generally desirable to increase their capability to resist sidewall damage such as splitting, puncture, rupture, or other sidewall damaging events caused by contact during tire use.
Features can be added along the sidewall to help resist certain sidewall damage. Lugs, blocks, and/or other tread features can be added about the sidewall to protect it from aggression by remaining between a dangerous obstacle and the sidewall as the tire interacts with the obstacle during operation. The addition of features along the sidewall adds material, complexity, and expense to a tire. Such features can also unfavorably reduce the flexibility of the sidewall. Therefore, it is desirable to optimize the size and positioning of such features particularly when not all portions of the sidewall necessarily need protection. Also, such features along the sidewall can significantly alter the appearance of the tire. Consequently, aesthetic concerns play a significant role in determining the shape and location of features added to the sidewall.
Accordingly, a tire with improved resistance to sidewall damage from obstacles encountered during tire operation is needed. More particularly, a tire with protective features positioned along the sidewall in a manner that improves resistance to splitting, puncture, and other potential damage would be useful. A tire having such features while also satisfying aesthetic considerations would also be particularly useful.
SUMMARY OF THE INVENTION
Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In one exemplary embodiment, a tire having improved protection against obstacles damaging the sidewall is provided. The tire defines an equator and has tread blocks and tread grooves positioned along a shoulder of the tire. The tire includes a plurality of block-based tread features located along the sidewall of the tire. The block-based tread features are positioned along the tire based upon the radial position of the equator, LPN, and a first area in which an obstacle would move along the sidewall of the tire if the obstacle slipped off a tread block as the tire moved past the obstacle. A plurality of groove-based tread features are located along the sidewall of the tire. The groove-based tread features are positioned along the tire based upon the radial position of LPN, LPG, and a second area in which an obstacle would move along the sidewall of the tire if the obstacle slipped off a tread block as the tire moved past the obstacle.
In certain embodiments, the groove-based tread feature and the block-based tread feature each have a thickness in the range of about 3 mm to about 15 mm. The groove-based tread features can be positioned closer to the summit of the tire than the block-based features. The position of the block-based tread feature along the sidewall of the tire may be coextensive with a block-based contact region defined by the equator, LPN, and the first area. Similarly, the position of the groove-based tread feature along the sidewall of the tire may be coextensive with a groove-based contact region defined by the LPN, LPG, and the second area. The radial depth of the groove-based tread feature can extend beyond LPN, especially when the thickness of the groove-based tread feature is less than 3 mm. The radial depth of the block-based tread feature can also extend beyond the equator, especially when the thickness of the block-based tread feature is less than 3 mm.
Preferably, in certain embodiments, the distance along the radial direction between the top and the bottom of the groove-based feature is at least 10 mm. Similarly, the distance along the radial direction between the top and the bottom of the block-based feature is preferably at least 10 mm in certain embodiments.
The first area and second area can be determined using the following equations:
r = ( L o - R θ ) 2 + H o 2 α = θ + arctan H o L o - R θ
where:
R=radius of the tire θ=the amount of the tire's rotation L o =the initial horizontal position of the obstacle P 0 relative to the tire center O H o =the initial vertical position of the obstacle P 0 relative to the tire center O r=the radial coordinate of the obstacle α=the angular coordinate of the obstacle
Alternatively, the first area and second area can be determined experimentally. LPN and LPG can be determined experimentally or can be determined by mathematical modeling.
In certain embodiments, the groove-based features and the block-based features are staggered along the circumferential direction of the sidewall. In still other embodiments, the groove-based features and the block-based features may have different thicknesses.
In still another exemplary embodiment of the present invention, a tire having improved protection against obstacles damaging the sidewall is provided. The tire has an equator, a summit, and defines radial directions. The tire has tread blocks and tread grooves positioned along a shoulder of the tire. The tire comprises a plurality of block-based tread features located along the sidewall of the tire. The block-based features are positioned radially below respective tread blocks located along the shoulder of the tire. A plurality of groove-based tread features are located along the sidewall of the tire. The groove-based features are positioned radially below respective tread grooves located along the shoulder of the tire. The groove-based tread features are positioned closer to the summit of the tire than the block-based tread features.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
FIG. 1 illustrates an exemplary trace along the sidewall of a tire that is represented schematically.
FIGS. 2A through 2C illustrate a sectional views of a tire schematic for purposes described in the specification below.
FIG. 3A is a side view of an exemplary tire showing traces along the sidewall of the tire as well as a circles positioned at the equator, LPN, LPG, and the rim seating location as described below.
FIGS. 3B and 3C are close-up views of a portion of the sidewall of the exemplary tire shown in FIG. 3A .
FIG. 4 illustrates a portion of a representative sidewall for purposes of further describing an exemplary procedure for positioning tread features along the sidewall.
DETAILED DESCRIPTION OF THE INVENTION
For purposes of describing the invention, reference now will be made in detail to embodiments and aspects of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, from the teachings disclosed herein, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
As used herein, the following terms are defined as follows:
Radial refers to directions perpendicular to the axis of rotation of the tire.
LPN refers to the radial position at which an obstacle would first contact the sidewall of the tire if the obstacle slipped off an edge of a tread block as the tire rotates along its path after making contact with the obstacle.
LPG refers to the radial position at which the obstacle would first contact the sidewall of the tire if the obstacle slipped off an edge of a tread groove as the tire rotates along its path after making contact with the obstacle.
Equator refers to the radial location along the sidewall at which the tire is widest as viewed in a cross section taken along a plane perpendicular to the circumferential direction of the tire.
Trace refers to the path a point of contact of an obstacle would make along the sidewall of a tire as the tire rotated past, and in a non-deforming contact with, the obstacle.
As a tire rolls along a surface during operation, the sidewall may come into contact with an obstacle capable of damaging the sidewall by splitting or puncturing. For purposes of describing the invention, assume that such an obstacle can be represented by a single point of contact that begins along the tread region of the tire and then moves along the tire sidewall as the tire rotates. As the tire rolls past such an obstacle, the point of contact with the obstacle will follow a path—referred to herein as a trace—along the sidewall of the tire. By way of example, assuming that the sidewall is flat and undamaged by contact with the obstacle, this trace can be characterized mathematically by the following equations:
r = ( L o - R θ ) 2 + H o 2
α = θ + arctan H o L o - R θ ( 1 ) & ( 2 )
where:
R=radius of the tire θ=the amount of the tire's rotation L o =the initial horizontal position of the obstacle P 0 relative to the tire center O H o =the initial vertical position of the obstacle P 0 relative to the tire center O r=the radial coordinate of the obstacle α=the angular coordinate of the obstacle
Accordingly, as illustrated in FIG. 1A , assuming an obstacle initially contacts tire 100 at point P 0 along the tread region 105 , trace T illustrates the path that the obstacle will make along the sidewall 110 of the tire 100 as calculated using equations 1 and 2. Equations 1 and 2 are provided by way of example. Other mathematical models may be used for determining the trace or such can be determined experimentally as well.
One mode of sidewall splitting that can occur is when a tire initially rolls into contact with an obstacle and the tire subsequently slips off the obstacle. For example, as tire 100 encounters an obstacle in its path, initial contact may occur between tread region 105 and the obstacle. However, as tire 100 rotates, the tread region 105 may slip off the obstacle leading to undesired contact with the sidewall 110 . Accordingly, an important step in improving the resistance of sidewall 110 to damage is to determine where the obstacle will make contact with sidewall 110 when such a slip occurs. The location will likely be different depending upon whether the obstacle slips off the edge of a tread block or the edge of a tread groove.
Referring now to FIG. 2A , point N represents the edge of a tread block 160 ( FIG. 3A ) and point G represents the edge of a tread groove 170 ( FIG. 3A ) within tread region 105 . If the obstacle slips off point N (i.e. an edge of a tread block 160 ), then LPN represents the radial position along sidewall 110 at which the obstacle will land or first make contact with sidewall 110 . If the obstacles slips off point G (i.e. an edge of a tread groove 170 ), then LPG represents the radial position along sidewall 110 at which the obstacle will first make contact with sidewall 110 .
The radial position of LPG or LPN can be determined mathematically or by experiment. For example, FIGS. 2B and 2C provide an exemplary illustration of a numerical method for determining LPN and LPG, respectively. First, beginning with FIG. 2B , a straight line 10 is drawn that passes through point N and point G. Next, a straight line 20 is constructed tangent to the tire carcass 115 at the location where line 10 passes through carcass 115 . Straight line 30 is then drawn perpendicular to line 20 and through the point where lines 10 and 20 intersect. Length 40 represents the distance along sidewall 110 from point N to line 30 . Length 50 is equal to length 40 and represents the distance of LPN from line 30 along sidewall 110 . Similarly, the position of LPG can be determined as shown in FIG. 2C . Length 60 represents the distance along sidewall 110 from point G to line 30 . Length 70 is equal to length 60 and represents the distance of LPG from line 30 along the sidewall 110 .
The final positions of LPG and LPN as calculated using the above technique may need to be adjusted based on the particular construction of the tire and/or the off-road conditions anticipated during its use. It has been determined that the final positions of LPN and LPG may be located at about −15 mm to +5 mm along sidewall 110 from the positions calculated using the technique shown in FIGS. 2B and 2C . As previously stated, the positions of LPG and LPN can be determined by other methods as well. For example, experiments can be conducted to determine the actual location along sidewall 110 at which an obstacle makes contact after slipping off tread groove 170 or tread block 160 .
FIG. 3A is a side view of tire 100 with sidewall 110 and tread region 105 shown in more detail. Using the calculation of LPN and LPG, circles 140 and 150 have been superimposed onto sidewall 110 . Circle 140 represents the circumferential position of LPN about the sidewall 110 of tire 100 while circle 150 represents the circumferential position of LPG about the sidewall 110 . LPG's circle 150 will always be located closer to the tread region 105 than LPN's circle 140 . Circle 130 represents the position of the equator of tire 110 . Circle 120 represents the location on tire 100 where a rim would be received. Tread region 105 of tire 100 also includes tread blocks 160 and tread grooves 170 along the tire shoulder as shown. Blocks and grooves having shapes and sizes other than as shown in FIG. 3A may also be used with the present invention as well.
Using equations 1 and 2 above, the traces for an obstacle slipping off the edges of a tread block 160 and a tread groove 170 have been calculated and superimposed onto sidewall 110 . More specifically, as shown in FIGS. 3A thru 3 C, trace 180 brackets a tread groove 170 between ends 175 and defines an area within which an obstacle would move if the obstacle started anywhere in the groove 170 as tire 100 rotates into contact with, and then past, the obstacle. Similarly, trace 190 brackets a tread block 160 with ends 165 and defines an area within which an obstacle would move if the obstacle started anywhere on the tread block 160 as the tire 100 rotates into contact with, and then past, the obstacle. More specifically, referring now to FIG. 3B , if an obstacle slips off of tread groove 170 during operation, the obstacle will move between the curves of groove-based trace 180 . Similarly, referring to FIG. 3C , if an obstacle slips off of tread block 160 during operation, the obstacle will move between the curves of block-based trace 190 .
Accordingly, traces 180 and 190 along with circles 120 , 130 , and 140 assist in identifying one ore more contact regions of concern for splitting or puncture of sidewall 110 during operation of tire 100 . Consequently, these contact regions represent preferred locations for the consideration of adding protection such as the addition of tread features to sidewall 110 . Aesthetic considerations can also be applied using the identification of these contact regions.
For example, referring to FIG. 3B , groove-based contact region 200 (represented by cross-hatching) denotes a preferred position for adding a tread feature to protect sidewall 110 against an obstacle that slips off of a groove 170 . Contact region 200 is bounded by trace 180 , LPN circle 140 , and LPG circle 150 . The thickness of the tread feature (i.e. the height of the tread feature above the surrounding sidewall 110 ) to be added at contact region 200 is determined by how much improvement in performance is desired. Normally, such a tread feature should be in the range of about 3 mm to about 15 mm in thickness. Thicker features will provide more protection but at increased cost in materials and the addition of weight to the tire. It may also generate excessive heat that may damage the tire during prolonged operations. Thinner features, i.e., less than 3 mm can also be used but it may be desirable to extend the bottom of the tread feature (line b) beyond LPN circle 140 to provide additional protection. Regardless, preferably the distance between top of the tread feature (line a) and the bottom of the tread feature (line b) should be at least about 10 mm along the radial direction and need not be precisely located at circles 140 and 150 , respectively.
Similarly, block-based contact region 210 (represented by cross-hatching) in FIG. 3C indicates a preferred position for adding a tread feature to protect against an obstacle that slips off of a tread block 160 . Region 210 is bounded by trace 190 , equator circle 130 , and LPN circle 140 . Again, the thickness of the tread feature is preferably in the range of about 3 mm to about 15 mm depending upon the amount of protection desired. Features less than 3 mm in thickness may require moving the bottom of the feature (line B) beyond the equator circle 130 so as to provide additional protection. Preferably the distance between the top of the tread feature (line A) and the bottom of the tread feature (line B) should be at least about 10 mm along the radial direction.
Depending upon the relative widths of tread blocks and grooves for a particular tire construction, the addition of tread features as described above may result in overlap. For example, if tread features are positioned coextensive with the contact region 210 for each of the tread blocks 160 on tire 100 , a continuous rib or ring will be formed on sidewall 110 . While such a feature may offer much protection to the sidewall 105 , a solid ring may not be satisfactory from an aesthetic perspective or from the standpoint of mud traction. It may also generate excessive heat that may damage the tire during prolonged operations. Accordingly, using information provided by identifying the contact regions as described above, tread features may be staggered or otherwise shaped and manipulated along the sidewall in order to optimize sidewall protection while also addressing other concerns such as aesthetics, mud traction, and heat generation. In addition, tread features may be positioned coextensive or somewhat offset from the contact regions while still providing sidewall protection based on knowing the location of the anticipated contact regions.
FIG. 4 represents a portion of a tire 400 having tread blocks 460 and tread grooves 470 . Also shown is trace 480 based on the edges of groove 470 and trace 490 based on the edges of block 460 . Using the methods described above, groove-based tread features 500 have been positioned radially below grooves 470 to protect sidewall 410 from obstacles slipping off the grooves. Similarly, block-based tread features 510 have been positioned radially below blocks 460 to protect sidewall 410 from obstacles slipping off the blocks. In order to improve aesthetic appeal, features 500 and 510 have been shaped and staggered as shown in FIG. 4 . Other shapes and orientations may be applied. However, the positioning of such features is informed using the methods described herein.
While the present subject matter has been described in detail with respect to specific exemplary embodiments and methods thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.
|
A tire with improved resistance to sidewall damage such as splitting or puncture is provided. More particularly, the present invention provides a tire with tread features positioned along the sidewall in a manner that improves the protection of the sidewall against damage when contacting obstacles during operation of the tire.
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for reducing or eliminating the problem of edge overdrying which occurs during the drying process in the manufacture of paper. It also includes a paper machine drying cylinder which is suitably coated to achieve this objective.
2. Description of the Prior Art
Conventional paper machine drying sections comprise a large number (40 to 60) of rotating, steam-heated cast iron cylinders arranged in two tiers. Paper is dried to solids content around 93% by alternately pressing the top and bottom sides of the paper web against these cylinders as it passes through the dryer in a serpentine fashion. The tendency of overdrying the paper edges is a common problem which affects almost all newsprint, fine paper and specialty grade paper machines. Without any compensation for this effect, the typical cross-machine direction (CD) moisture profile of the paper is non-uniform because of the lower moisture content of the edges of the sheet.
Non-uniform CD moisture profiles lead to non-uniform CD paper properties. In particular, problems with dimensional stability, cockle, curl, grainy edges, and damaged fibers may arise. These are undesirable in the final papermaking steps as well as in the final printing and converting operations. Overdried edges are also problematic in another way, namely they are a cause of web breaks that lead to decreased machine productivity.
There are a number of factors which combine to create the problem of overdried edges. The relative importance of these factors varies from machine to machine. Starting with the forming and pressing operations, a low basis weight (dry mass) or a low moisture content at the edge of the production section will invariably result in overdried edges.
In the drying section, the passage of the cool, wet paper on the steam-heated cylinders reduces the cylinder surface temperature. However at the cylinder edges, where there is no contact with paper, the temperature can be considerably higher than in the paper covered areas. Heat flows by conduction from the overheated cylinder edges towards the paper, resulting in localized overdrying in at least several inches of the paper edges. In addition to overdrying resulting from heat transfer phenomena, mass transfer considerations are also important. The improved ventilation and decreased humidity of the ventilating air at the dryer edges (compared to the central portion) may also lead to overdried paper edges, although in this case the problem is generally less localized. Improper operation of the cylinders especially with respect to steam condensate removal can cause non-uniform CD moisture profiles, but not restricted necessarily to the paper edges.
In some cases, overdried edges are cut off and returned to the pulper, which decreases productivity. Some commonly used operational type of solutions to the problem of overdried edges are modification of the basis weight and/or moisture profile coming out of the forming and pressing sections, and CD moisture profile control methods such as remoisturizing. Although the formation of a sheet with heavier edges will result in a uniform moisture profile, it does so by producing a non-uniform dry basis weight which results in non-uniform CD properties. The high cost of furnish is a further deterrent to this solution. The production of a non-uniform moisture profile after the press section through the use of steam showers means that expensive equipment and control systems must be purchased and installed in a physically constrained area. The wetter sheet edges often lead to sheet breaks. Finally, the use of profiling water showers in the dryer section is an expensive, maintenance intensive option which increases the steam usage in the dryer section and often leads to wrinkles at the paper edges.
The concept of using insulating material on the interior peripheral surface at both ends of the drying cylinder to prevent overdrying of the paper web edges is described for example in U.S. Pat. No. 4,379,369; in this example the insulation is held in place by adhesive or vulcanizing. Despite the fact that several companies offer an internally installed drying cylinder insulation system to prevent edge overdrying using either spring-loaded rods or an adhesive to secure the insulation, only a few installations are known to have been made to date. The use of such insulators has not become popular for a number of reasons. Paper machine operators are hesitant to install equipment inside a cylinder since it can not be easily inspected and has the potential of causing severe damage to the cylinder. As well, even though the inside surface of the cylinder is insulated, heat can still conduct through the thick (1 to 2 inch) cast iron wall of the cylinder resulting in high temperatures at the cylinder edges.
The installation of various foil, fabric or sheet material on the outside surface edges of the cylinder for the purpose of preventing edge overdrying is described, for example, in U.S. Pat. Nos. 4,192,080, 4,639,291 and 4,639,292. The material is secured to the cylinder surface with glue. The disadvantages of this technique include the non-permanent method of attachment, the large fabric thickness and/or number of treated cylinders required to accomplish the desired effect, and the lack of ability to vary the degree of surface temperature correction. There are no known commercial users of this technique.
Numerous patents describe the insulation by various means of the drying cylinder end faces, rather than of the cylinder periphery at the ends (e.g. U.S. Pat. Nos. 4,450,631 and 4,399,169). Unlike the present invention, the purpose of those patents is to prevent heat loss from the end plates of the drying cylinders; however with the advent of enclosed dryer sections this is now rarely a concern.
Other approaches to preventing paper edge overdrying include tightening the dryer felt at the center, modifying the CD permeability of the dryer felt (e.g. Canadian patent 960,543), and altering the traditional design of the cast iron drying cylinder. With respect to this last approach, the prior art describes, for example, cylinders with internal compartments at the ends that are heated with lower temperature fluid than the rest of the cylinder (Canadian patent 886,644), and cylinders with grooves or channels to allow condensate build-up near the ends (Japanese Kokai 159,390/81). Some of these methods are difficult or impossible to retrofit to existing paper machine drying sections.
Coatings are utilized for a variety of reasons on many types of paper machine rolls, although the prior art does not appear to describe any applications of coatings for paper machine drying cylinders. In all cases known to the applicants, the coating is applied across the entire width of a roll in a uniform fashion and is thus unable to address the problem of surface temperature non-uniformity. The usual intent is to improve the adhesion/release properties, surface finish, or corrosion/wear resistance. Several examples of coatings on rolls described in the prior art are given below.
U.S. Pat. Nos. 4,748,736 and 5,167,068 describe methods of coating a roll with metallic/ceramic surface with adhesion/release properties suitable for replacing the conventionally used granite press rolls. The coating of a roll, especially press and calender rolls, with a resilient polymer followed by a wear resistant layer to control hardness/wear resistance is described in U.S. Pat. No. 5,176,940. U.S. Pat. Nos. 5,252,185 and 5,171,404 describe a thermally applied tungsten carbide or chromium carbide coating on a heated calender roll to provide an abrasive resistant surface. U.S. Pat. Nos. 5,353,521 and 5,272,821 describe the coating of a heated impulse drying roll surface to lower its thermal diffusivity, where impulse drying is that process where a wet paper web passes through a press nip with one of the rolls heated to a high (200° C. to 400° C.) temperature. After impulse drying the sheet solids content is typically 40% to 60%. The low thermal diffusivity of the roll is said to suppress sheet delamination (sheet splitting) by substantially reducing the extent of energy transfer in the later stages of the impulse drying process, thereby reducing the energy available for flash evaporation.
U.S. Pat. No. 5,223,099 describes a method of combining a roll coating and an external heating device such that the heating radiation penetrates through the paper to the roll face, but does not heat the roll at a depth greater than the roll face. The invention is to be used for example on a press or calender roll, with the particular objective of being able to better control the detachment of the web from the roll surface by controlling the surface temperature.
For rolls used in the tissue rather than papermaking industry, full-face thermal spray coatings of molybdenum or stainless steel for Yankee tissue drying cylinders have been used for about 15 years to prevent corrosion and wear.
For rolls not used in the paper industry, U.S. Pat. No. 4,912,835 describes a thermally sprayed cermet coating on rolls used in the manufacture of metal sheets, with the objective of providing the right coefficient of friction and durability to enhance productivity.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to obviate the disadvantages of the prior art and to provide a simple and efficient solution to the problem of overdried paper edges by applying a thin ceramic coating onto the circumferential exterior surface of paper drying cylinders near the cylinder edges, thereby forming a thermal barrier coating at the edges which decreases paper drying rate at said edges and reduces or eliminates paper edge overdrying.
Another object is to control the drying temperature at the edge of the cylinder by providing a thermal barrier coating which is suitably graded in the cross-direction of the cylinder.
Other objects and advantages of the invention will become apparent from the following description thereof.
The solution to the problem of overdried paper edges according to the present invention involves the surface application of a thin ceramic layer to the edges of drying cylinders in order to physically engineer the heat transfer characteristics of the cylinders. Specifically, this new approach involves the thermal spraying of a ceramic thermal barrier coating (TBC) on the edges of the drying cylinder not covered by paper and also for a certain distance under the area where the paper runs on the cylinder. This creates a thermal insulation and reduces the heat transferred to the paper edges from the overheated cylinder edges.
The thickness of the coating is preferably graded in the cross-direction of the cylinder, so that there is no step change in thickness and no significant gradient change in temperature across the cylinder. The TBC thickness required to effect the desired reduction in dryer cylinder surface temperature depends on the non-uniformity of the dryer surface temperature profile; typically a temperature reduction of the order of 6° C. per 100 μm thickness of TBC can be expected. The graded coating is thickest at the outer edge where overheating is greatest.
Moreover, there is preferably provided a bond coat between the cylinder surface and the TBC to reduce the stress caused by the difference in thermal expansion of the cylinder base material and the ceramic coating. This bond coat usually consists of a material whose thermal expansion closely matches the thermal expansion of the ceramic coating, and preferably has a low porosity to prevent diffusion of oxygen or other chemicals into the base material of the cylinder, normally cast iron. This bond coat will generally have a thickness from about 20 to 100 μ and preferably 50-60 μm, and will usually be a metal alloy such as an alloy of nickel, chromium or cobalt. For example an alloy made of Ni and containing 5% Al is particularly suitable as the bond coat. Also, it is desirable that the bond coat should have a surface roughness of 7-12 μm to provide a satisfactory adhesion between the bond coat and the ceramic coating. The bond coat is usually applied onto the cylinder by thermal spraying such as plasma spraying. The cylinder is usually sandblasted prior to the bond coat application.
The ceramic coating itself will be selected from suitable ceramic materials such as titanium oxide, zirconium oxide, aluminum oxide and chromium oxide. A particularly preferred material is a partially stabilized zirconia, such as ZrO 2 partially stabilized with Y 2 O 3 . The thickness of the ceramic coating is normally varied between 0 and 400 μm depending on the surface temperature drop required in the cross direction of the cylinder.
Preferably the ceramic coating has 10%-30% porosity to reduce the thermal conductivity of the coating and prevent propagation of stress induced cracks and the surface roughness of the ceramic coating is maintained generally below 7 μm to avoid damage to the paper contacting the cylinder. Such ceramic coatings are usually applied to the surface of the cylinder or onto the surface of the bond coat, by thermal spraying, such as plasma spaying which may be carried out by means of a plasma torch. Preferably the ceramic coating is applied in multiple passes of the plasma torch, each pass depositing a ceramic layer 10-50 μm thick. Obviously a paper machine drying cylinder having such ceramic coating or TBC near the edges of the cylinder is part of the present invention.
There are many advantages to the solution described herein. This modern approach does not require disassembly of the dryer cans, has no risk of detachment and yet can be removed, if necessary. There are no moving parts or operating costs. This invention requires no control package, water/steam supply, maintenance or special care by mill personnel once installed. It is easily optimized, and does not mark the paper. Rather than masking the problem or correcting it after it occurs, this solution prevents the formation of overdried edges by lowering the dryer cylinder edge temperature. This lowers the heat transfer to the paper and decreases the drying rate at the edges.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention will now be described with reference to the appended drawings, in which:
FIG. 1 represents a partial schematic view, in perspective, of a paper machine drying cylinder, coated at one of its edges with a ceramic coating in accordance with the present invention;
FIG. 2 is a view along section 2--2 of FIG. 1, showing the coating on an enlarged scale; and
FIG. 3 represents a graph showing the variation of drying cylinder surface temperature with and without ceramic coating and the thickness of the coating as a function of distance from the cylinder edge.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention is illustrated, but not limited by the appended drawings where the same reference numbers are used to describe the same parts in all figures.
Referring to FIG. 1, it illustrates a paper machine drying cylinder 10 with a TBC ceramic coating 12 applied on the circumferential external surface 14 near the edge or extremity 16 of the drying cylinder 10. The paper sheet 18 passes on the cylinder surface 14 so that the edge 20 of the sheet stays on top of the TBC.
The preferred coating 12 consists of two distinct layers 22 and 24 and is applied on the circumferential outer surface 14 near the drying cylinder extremity 16, as shown in FIG. 2, which is not drawn to scale. The first layer 22 which is applied directly onto the prepared surface 14 of the cylinder 10 in a uniformly thick layer, is the bond coat. The second layer 24 is a thermal barrier coating (TBC) which is applied on top of the bond coat 22 in a graded fashion. The characteristics of the coating 12 which are critical in determining the coating's performance include: (i) thickness of bond and TBC layers; (ii) porosity of bond and TBC layers; (iii) adhesion strength; (iv) surface roughness; and (v) thermal insulating characteristics.
As mentioned above, prior to the application of the thermal barrier coating 24, a bond coat 22 may be used. The bond coat 22 is applied directly on the surface 14 of the drying cylinder 10 in order to reduce the stress in the coating caused by the difference in the thermal expansion of the cylinder's base material (cast iron) and the ceramic layer. The bond coating 22 composition can consist of a variety of nickel and/or cobalt based alloys. The preferred material for this application is Ni containing 5% Al. The bond coat should be made of a material whose thermal expansion closely matches the thermal expansion of the ceramic TBC layer. Furthermore, the preferred bond layer is resistant to oxidation and corrosion in the operating environment. The preferred bond layer for this application is a Ni-5% Al, however, other nickel, chromium and cobalt alloys could be used. The preferred thickness of the bond layer is 60 μm, however, the thickness could be varied from about 20-100 μm. The porosity of the bond layer should be as low as possible to prevent diffusion of oxygen or other chemicals into the base material. The adhesion of the bond layer to the cast iron base material is improved by sandblasting and cleaning the cast iron prior to the application of the bond layer. The bond coat is usually applied onto the cylinder by thermal spraying, such as plasma spraying.
A wide variety of ceramics could be used as thermal barriers. The oxides of metals such as titanium, zirconium, aluminum and chromium are relatively inexpensive and, therefore, their application as thermal barrier coatings is economically feasible. The preferred material is partially stabilized zirconia (ZrO 2 ). Zirconia has very low thermal conductivity and good wear resistance. As such, zirconia is the material of choice for thermal barrier coatings used in the aerospace and gas turbine industries. However, zirconia exhibits three well-defined polymorphs: the monoclinic, tetragonal, and cubic phases. The monoclinic phase is stable up to about 1170° C. where it transforms to the tetragonal phase. At 2370° C. the tetragonal phase transforms to the cubic phase. The concern is that as the zirconia is being sprayed it is heated to temperatures near its melting point (2680° C.). Upon cooling it transforms back to its monoclinic phase and grows in volume by 3 to 5%. This expansion can result in cracking and coating detachment. Thus additives, such as calcia (CaO), magnesia (MgO), yttria (Y 2 O 3 ), or ceria (CeO 2 ) must be mixed with the zirconia to stabilize the material in either the tetragonal or the cubic phase. The material preferred for this application is ZrO 2 -8%Y 2 O 3 .
The preferred TCB layer has 10%-30% porosity. The porosity is used to reduce the thermal conductivity of the TBC layer and to prevent the propagation of stress-induced cracks. The thickness of the TBC ceramic layer can be varied according to the temperature drop required. The reduction in surface temperature which can be obtained using ZrO 2 -8%Y 2 O 3 TBC with 20% porosity, at the heat flux and surface temperature which is typical of an operating drying cylinder, has been measured at 6° C. per 100 μm of TBC thickness. The preferred thickness of the TBC layer is varied between 0 and 400 μm depending on the surface temperature drop required in the cross direction profile of the drying cylinder.
The preferred surface roughness of the bond layer is 7-12 μm which is controlled by selecting suitable size powders for spraying and optimizing the spraying parameters. The roughness of the bond layer is important in determining the adhesion strength between the bond layer and the TBC layer. The preferred adhesion of the TBC layer is in excess of 8 MPa. The surface roughness of the TBC layer is maintained below 7 μm by controlling the size of the powders used and the operating parameters during spraying. Excessive surface roughness of the TBC layer may damage the paper contacting the cylinder.
Both the bond coat and the ceramic coating can be applied on dryer cylinders using a number of thermal spraying technologies, such as, plasma spraying, high-velocity oxy-fuel (H.V.O.F.), and flame spraying. The preferred application process for the purpose of the present invention is plasma spraying. In the preferred coating application process, the plasma torch is attached to a torch moving mechanism. During spraying, the mechanism moves the torch across the length of the cylinder in a preprogrammed routine, while the cylinder is rotated. The duration of spraying, the spraying rate, the rotational velocity of the cylinder, and the linear velocity of the moving torch are controlled to obtain the desired coating thickness. The coating is applied in multiple passes, each pass depositing a bond layer of 20-100 μm thick or a TBC layer 10-50 μm thick.
In the preferred coating application process, the plasma torch is used to generate a jet whose temperature is in excess of 5000° C. and whose velocity is in excess of 100 m/sec. The selected powder is fed into the plasma jet through a powder feeder and a powder injector. The powder is entrained by the plasma jet, where it is melted and accelerated towards the cylinder's surface. On the cylinder, the powder splats, cools and solidifies into a TBC layer.
The number of cylinders to be treated depends on the extent of the edge overdrying problem, the operating characteristics of the particular dryer, and the corrected temperature profile after the coating application. The number will typically range from 2 to 10, with a coating applied at each extremity of the cylinder. The width of cylinder coated depends on the area of the cylinder which is overheated and the distance of the paper from the cylinder edge.
FIG. 3 represents a graphical illustration of results achieved with the present invention in an example which is described below.
EXAMPLE
FIG. 3 shows the non-uniform temperature profile (line A) of a typical drying cylinder as measured in a mill environment. Line B shows an example of a temperature profile achieved with a TBC of the present invention and line C shows the TBC thickness required to achieve this profile, based on laboratory results. In this example it can be seen that the coating thickness varies from about 225 microns at the edge of the cylinder to 0 microns 18 inches from the edge.
It should be understood that the invention is not limited to the specific embodiments described above, but that many modifications obvious to those skilled in the art can be made without departing from the spirit of the invention and the scope of the following claims.
|
The invention overcomes the problem of paper edge overdrying during the paper drying process on paper machine drying cylinders. It comprises applying a thin ceramic coating onto the circumferential exterior surface of the cylinder near the cylinder edges, thereby forming a thermal barrier coating which decreases paper drying rate at said edges and reduces or eliminates paper edge overdrying.
| 3
|
BACKGROUND AND SUMMARY OF INVENTION
This invention relates to a locking device for excavating equipment and, more particularly, to a device including a C-shaped clamp member and a wedge member useful in securing an adapter to the lip of a shovel dipper bucket, etc.
This invention is related to the co-pending application of Frederick C. Hahn and Larren F. Jones, Ser. No. 112,160, filed Jan. 16, 1980 to which reference may be made for additional details of construction not specified here.
For years, workers in the excavating tooth fastening art have been entrigued by the idea of using corrugated pins and locks to develop greater holding power in the lock. In this connection, reference may be made to co-owned U.S. Pat. Nos. 3,126,654 and 4,061,432. In some instances, the art workers have gone to a ratchet type of corrugation--see U.S. Pat. No. 3,722,932--because of the ease of installation but the greater resistance to inadvertent disassembly. However, conventional ratchets as seen in the '932 patent are unsatisfactory because when it does comes time to disassemble, this is very difficult.
The mutually exclusive problems of good, strong holding power during operation yet easy disassembly when desired have been reconciled according to the instant invention which makes use of a unique lock engaging the ratchet which is partly metal and partly resilient material such as rubber and which is conveniently upsetable when disassembly is indicated.
DETAILED DESCRIPTION
The invention is described in conjunction with an illustrative embodiment in the accompanying drawing, in which
FIG. 1 is a fragmentary perspective view of a dipper lip equipped with an adapter and showing the inventive lock in the process of assembly;
FIG. 2 is a view similar to FIG. 1 but showing the lock installed in place with the lock parts in section to show engagement thereof and in which the lock is in the process of being disassembled;
FIG. 3 is a fragmentary side elevational view, partially broken away showing the working parts of the inventive lock;
FIG. 4 is an enlarged sectional view taken along the sight line 4--4 of FIG. 3;
FIG. 5 is a front elevational view of the arcuate lock portion of the invention; and
FIG. 6 is a fragmentary perspective view of the top portion of the C-clamp showing the locking shoulders which releasably restrain the arcuate lock member in position until disassembly is indicated.
In the illustration given and with reference first to FIG. 1, the numeral 10 designates generally a portion of the lip of an excavating machine such as the shovel dipper, drag line bucket, etc., and which is equipped with a plurality of spaced apart openings slightly rearward of the forward edge of the lip--one of which is indicated at 11. Straddling the lip 11 is an adapter 12 equipped with the usual forwardly projecting nose 13 for the receipt of a point (not shown). For the purpose of straddling the lip 10, the adapter 12 is equipped with rearwardly extending legs 14 and 15 each of which is equipped with a lock receiving opening as at 16 and 17, respectively. In FIG. 1, a C-shaped clamp member 18 shown installed in the aligned openings 16, 11, 17.
Cooperating with the clamp member 18 in locking the adapter 12 in place on the lip 10 is a wedge member 19 and a lock member generally designated 20. The way the members 18-20 are assembled can be appreciated from a consideration of FIG. 3.
In FIG. 3, it is seen that the wedge member 19 is equipped with a rear face 21 on which are provided a plurality of serrations in the form of ratchet teeth 22. The wedge shape is developed by longitudinally tapering the front wall 23 relative to the rear face 21. As can be appreciated from a consideration of FIG. 4, the ratchet teeth 22 are narrower than the wedge 19 and are rearwardly tapered so as to sit within a correspondingly contoured slot 24 in the clamp member 18.
Referring again to FIG. 3, it will be noted that the clamp member 18 adjacent the upper end thereof is equipped with an arcuate passageway 25 in which is received the lock member 20. The lock member 20 has a forward portion as at 20a which is constructed of metal and terminates in a sloping face to develop a contour corresponding to that of the ratchet teeth. The rear portion 20b of the lock member 20 is constructed of resilient material such as rubber and is suitably bonded to the forward portion 20a. The rear portion 20b is seen in a temporary holding position by virtue of shoulders 26 provided within the passageway 25.
Referring now to FIG. 2, it will be seen that a screwdriver S is in the process of being inserted within the upper end 27 of the passageway 25 for the purpose of dislodging the resilient portion 20b from its "held" position under the shoulders 26. By bending the resilient portion 20b to the dotted line position designated 28 in FIG. 3, the lock between the lock member 20 and the wedge member 19 is released so that the lock member 20 can move further into the passageway 25 when the wedge member 19 is moved upwardly--as by applying force to the bottom thereof as at 19a by a sledge, hammer, etc.
The C-shaped clamp member 18 is reversible by virtue of being symmetrical about a mid-plane and is equipped with a lower passageway 25' (see FIG. 6) should the member 18 be inserted in reverse fashion from that shown in FIG. 3.
In the operation of the invention, the lock member 20 is normally inserted into the C-shaped clamp member 18 from the front, i.e., into the slot 24 defined between the sidewalls or flutes 29. This insures that the resilient portion 20b will engage the shoulders 26 with minimum of difficulty. This disposes the forward portion 20a between the flutes 29 and serves as a ratchet or pawl for the ratchet teeth 22 of the wedge member 19. Thereafter the wedge member 19 is inserted in the fashion depicted in FIG. 1 with the lock member 20 sliding along the sloping portions of the teeth 22 until the wedge member 19 is fully engaged. During this operation, the resilient portion 20b is alternately compressed and relaxed, the compression being implemented by virtue of bores 30 (see FIG. 5) within the resilient portion 20b. Simultaneous with the foregoing, the flutes 29 not only serve to guide the wedge member 19 but by lateral confinement serve to stabilize the movement into a linear downward movement and thus insure proper engagement of the lock member 20 therewith. The arrangement of the teeth 22 and the flutes 29 (see FIG. 4) in what might be considered a trapezoidal shape makes for an effective lock irrespective of dimensional variations arising out of casting techniques. Further, it is advantageous to undercut the teeth 22 slightly as at 22a (see FIG. 3) which avoids the possibility of build-up of material within the spaces between adjacent teeth and which might impair the seat between the teeth of the lock member 20. Thus, each time the wedge member 19 is to be reinstalled, it can be quickly cleaned of clinging debris by means of a wire brush or like available tool.
When removal of the adapter 12 is indicated, the previously referred to operation depicted in FIG. 2 is performed. The screwdriver S is inserted into the slot 31 (see FIG. 6) developed between the shoulders 26 so as to engage the upper end of the lock member 20 and pivot it to the dotted line position designated 28 wherein the resilient portion 20b now is disposed in the passageway enlargement 25a (see FIG. 6).
After the wedge member 19 has been removed, the lock member 20 is readily pushed back into the locking position shown in FIG. 3. The relaxed configuration of the lock member 20 is that illustrated in solid line in FIG. 3 wherein the resilient portion 20b is defined by essentially flat front and rear surfaces as contrasted to the arcuate front and rear surfaces of the forward metal portion 20a. This also facilitates the insertion of the lock member 20 into the passageway 25 at the time of initial assembly.
While in the foregoing specification a detailed description of an embodiment of the invention has been set down for the purpose of illustration, many variations in the details hereingiven may be made by those skilled in the art without departing from the spirit and scope of the invention.
|
A locking device for excavating equipment including a C-clamp member and a wedge member, the wedge member having ratchet-type teeth held in position against the C-clamp member by means of an arcuate lock which itself is resiliently mounted within the C-clamp member.
| 4
|
FIELD OF INVENTION
The present invention relates to a screening device for the separation of solid particulate material usually in the form of wood fibres, particularly in the recycling of newsprint.
BACKGROUND TO THE INVENTION
A significant proportion of newsprint is recycled. In a typical operation, the newsprint is pulped, screened to remove large containments, deinked, further screened to remove smaller containments, dewatered and then forwarded to stock make-up for a paper making machine.
During the screening operations, a variety of contaminants associated with the incoming newsprint are removed with generally larger and heavier contaminants being removed before smaller and lighter contaminants. For smooth and continuous operation of the recycling plant, it is essential that the screening operation further function efficiently. Unfortunately certain filters used in such operation are prone to plugging and screen wear.
Particulars problems have been encountered with a form of rotary screen filter which comprises a housing with which is fed the pulp for decontamination, a horizontal rotor which deems to circulate the pulp within the housing, and a circular accepts screen basket through which the decontaminated pulp is removed. The rejects fraction is slurried within the housing and is dumped from time to time.
The rotor is hollow and has external foils which assist both in circulation of the slurry within the housing and in expelling the accepts fraction through the screen basket. In proper operation, the screen feed is removed from the inlet by the foils past the screen basket through which the accepts fraction passes with the remainder moving past the rotor. The slurry is recirculated through the rotor interior and back for another pass. Such internal recycle is essential to ensure a proper separation of an accepts fraction from the rejects fraction.
However, heavy materials tend to build up on the interior surface of the rotor until eventually recirculation stops and the screen plugs. Attempting to close off the ends of the rotor and stop recirculation was not satisfactory, in that the coarse rejects particles simply rotate with the rotor foils and produce excessive wear of the screen.
A search in the facilities of the United States Patent and Trademark Office has located the following U.S. Pat. Nos. as the closest prior art:
1,134,304
2,621,793
4,238,324
4,287,055
4,316,768
4,697,982
This prior art describes a variety of screening devices for screening pulps but none addresses the plugging problem encountered with the horizontal hollow rotor screening device referred to above, nor do they suggest solutions to that problem.
SUMMARY OF INVENTION
In accordance with the present invention, the prior art plugging problem described above is overcome by modifying the structure of the rotor. In this regard, the internal wall of the rotor is structured so as to be outwardly tapered from the upstream end towards the downstream end and the hub supports which connect the rotor shell to the rotor hub and are located adjacent the downstream end of the rotor are elongate and are arranged at an angle to the axis of the rotor.
These modifications achieve a two-fold effect. The offset angle and vane-like shape of the hub supports creates pumping action within the rotor to pull material through the interior of the rotor, thereby assisting the rotor foil arrangement in creating recirculation. The sloping surface of the tapered or conical shape of the interior wall of the rotor causes heavy materials tending to accumulate at the wall under the centrifugal action of rotation of the rotor to slide towards the vanes, which then eject these heavy materials back into the feed chamber.
With this rotor arrangement, the screen filter has operated satisfactorily in the commercial facilities of the assignee without any noticeable build up of solids in the rotor interior and with only a minimal degree of screen wear.
Accordingly, in one aspect of the present invention, there is provided a rotary filter for separating an accepts fraction from a rejects fraction in an aqueous slurry of particulate material. The filter comprises housing means, inlet means to the housing for feeding the aqueous slurry thereto, outlet means from the housing for removing an accepts fraction therefrom, and screen means mounted in the housing in operative rotation to the outlet means and to permit the accepts fraction to pass therethrough and to prevent the rejects fraction from passing therethrough.
Rotor means is mounted within the housing adjacent the screen means for rotation about a generally horizontal axis. The rotor comprises a hollow cylindrical body, a hub and hub supports joining the hollow cylindrical body of the hub. The hollow cylindrical body has an internal surface which increases in diameter from a minimum diameter at one end to a maximum diameter. The hub and hub supports are located adjacent another end of the hollow cylindrical body with the hub supports being elongate in the axial direction of the rotor means and each being offset at an angle from the axis of the hollow cylindrical body.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic flow sheet of a typical newsprint processing and deinking plant for the recycle of newsprint;
FIG. 2 is a longitudinal sectional view of a screening device provided in accordance with one embodiment of the invention;
FIGS. 3 and 4 are perspective and end views respectively of the rotor used in the screening device of FIG. 2;
FIG. 5 is a close-up perspective view with parts cut-away for clarity, of the rotor used in the screening device of FIG. 2; and
FIG. 6 is a plan view of the rotor used in the screening device of FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIG. 1 of the drawings, a newsprint recycle plant 10 comprises a pulping station 12 to which the newsprint and other paper products are fed by line 14 and wherein the paper products are repulped with chemicals fed by line 16. The repulped material is fed by line 18 to a series of coarse filters 20 to remove a coarse fraction comprising heavy contaminants.
In the filtration operation 20, the pulp slurry is subjected to primary, secondary and tertiary screening in appropriate filters respectively to remove the heavy contaminants, with each screening providing an accepts fraction and a rejects fraction, with the accepts fraction being forwarded to a preceding screening except in the case of that for the primary screening and the rejects fraction being forwarded to a succeeding screening, except in the case of that produced in the tertiary screening.
The tertiary filter, therefore, has the heaviest load of the coarse and heavy particles and only a relatively minor proportion of the slurry comprises the desired paper pulp particles. It is this tertiary filter with which the present invention is concerned and which, prior to the invention, was the major screen plugging problem. Details of the construction of that filter are described below with respect to FIGS. 2 to 6.
The rejects fraction, containing the coarse and heavy contaminants separated from the slurry, is dumped from the tertiary filter by line 22. The accepts fraction, containing desired paper pulp particles, passes from the coarse filters 20 by line 24 to a deinking station 26 wherein ink is removed from the pulp in any desired manner.
Following deinking, the pulp slurry is forwarded by line 28 to fine filters 30 to remove small and heavy contaminants by line 32 to provide a pulp slurry in line 34 sufficiently purified for reuse in papermaking. The pulp slurry is forwarded to stock preparation at 36 with diluent water fed by line 38. The resultant slurry is forwarded by line 40 to a paper-making machine.
As mentioned above, the present invention is concerned specifically with the structure of the tertiary filter employed in the coarse filter 20. The tertiary filter is designed to run continuously, to carry a heavy load of contaminants and, prior to the present invention, was prone to plugging, requiring plant shutdown and filter clean-out. The structure of one embodiment of filter 22 is illustrated in FIGS. 2 to 6.
Referring now to FIGS. 2 to 6, a screening device comprises an enclosed housing 50 which is of generally cylindrical shape and which is mounted on suitable supports 52 and 54 with its axis horizontal.
The housing 50 has an inlet 56 for receipt of an aqueous slurry of solid particles into a feed chamber 58 within the housing 50 for the recovery of cellulosic pulp fibres therefrom as an accepts fraction.
The housing 50 also has an outlet 60 through which the accepts fraction is removed from the housing 50. A circular screen or basket 62 is mounted within the housing 50 to permit the accepts fraction to pass therethrough to the outlet 60. The screen basket 62 is dimensioned to permit the small particle accepts fraction to pass therethrough while preventing the coarse and heavy contaminants from passing through.
The accepts fraction generally contains not only the desired cellulosic fibres but also some small dimensioned contaminants. These are removed at a later processing stage, as described above with respect to FIG. 1.
The housing 50 has two further outlets 63 and 65 through which the rejects fraction is removed from time-to-time, the bulk of the rejects being removed through outlet pipe 63 while lighter rejects are removed through outlet pipe 65.
Mounted for rotation within the housing 50 is a rotor 64. The rotor 64 is of generally cylindrical shape and is positioned with its axis horizontal generally on the axis of the housing 50. The rotor 64 has a mounting hub 66 which is received on a drive shaft 67 extending to the exterior of the housing 50 and is operably connected to a drive rotor (not shown) in conventional manner. The rotor 64 is rotated in a clockwise manner as viewed from the rear end, as seen in FIG. 4.
The rotor 64 comprises a hollow cylindrical body 68 which is supported by the hub 66 by a plurality of vane-like elongate hub supports 70. The rotor 64 is positioned in the housing to be opposite to and in operative rotation to the screen basket 62. Provided on the external surface of the hollow cylindrical body 68 are a series of impellers or foils 72 (omitted in FIGS. 5 and 6 for clarity), which serve to induce circulation of the slurry from the feed chamber 58 past the stationary screen basket 62 to an anterior chamber 74, so that a slurry of the accepts fraction can pass through the screen basket 62. The rejects fraction accumulates in the anterior chamber 74 and is discharged therefrom from time to time through pipes 63 and 65.
The hollow cylindrical body 68 has a passageway 76 through which the slurry is recirculated to the feed chamber 58. Hence, the slurry is continuously received in the feed chamber 58 and is continuously recycled within the housing 50 first past the screen basket 62 for removal of a slurry of accepts particles to the anterior chamber 74 and back through the passageway 76 to the feed chamber 58.
This continuous recirculation is desirable having regard to the nature of the solids being processed and the relatively small quantity of particles of accepts size present therein. Not all such particles pass through the screen basket 62 at a single pass and continuous movement of the rejects heavy particles past the screen is desirable to avoid excessive abrasion.
In the conventional tertiary filter employed prior to the modification of the present invention, the hollow cylindrical body 68 had an inside diameter which was of the same dimension and the whole length of the passageway 76 and the hub supports 70 comprised four rectangular supports. As mentioned above, such unit was subject to plugging.
In accordance with the present invention, to avoid this plugging problem, two modifications have been made to the rotor 64. A first modification was to remove the rectangular hub supports and replace them by axially elongate vane-like hub supports 70. In the illustrated embodiment, there are six such hub supports, equally angularly displaced from one another at an angle of 60°. However, any desired number of such vanes 70, such as four, may be employed, commensurate with obtaining an adequate flow of slurry through the downstream and of the passageway 76, usually equally angularly offset from one another.
In addition to being axially elongate, the vanes 70 also are angularly offset by an angle B from the axis of the rotor 64 as most clearly seen in FIG. 6. This offset angle and the rotation of the rotor 64 create a pumping effect in the passageway 76 to assist the foils 72 in the recirculation of the slurry within the housing 50. The pumping action achieved by the vanes 70 may be sufficient to effect circulation of the slurry within the housing, permitting the impellers or foils 72 to be omitted and a continuous outer surface of the rotor body 68 to be employed.
The angle of offset of the axis of the vane 70 with respect to the axis of the rotor 64 may vary, depending on the exterior to which pumping is desired and generally may vary from about 10° to about 30°, and adequate results have been achieved with six such hub vanes 70 each offset at an angle of approximately 20°.
The other modification to the rotor 64 is to provide the inner wall 78 of the hollow cylindrical body 68 of a conical shape, whereby the diameter of the passageway 76 increases from a minimum at the upstream end 80 with respect to slurry flow through the passageway, in regular manner to a maximum diameter adjacent the hub supports 70. The effect of this tapering of the wall 78 is to prevent heavier particles from accumulating against the wall 78 under the centrifugal force tended to be applied thereto by rotation of the rotor as the slurry passes through the passageway. Instead, the slope of the wall in the direction of the flow of the slurry tends to urge the particles to slide downstream towards the hub vanes 70, for ejection back into the feed chamber 58.
Since making the two modifications approximately six months ago, the assignees testing filter 22 at its commercial newsprint recycling plant 10 at Thorold, Ontario, Canada has operated continuously with no sign of plugging on the interior of the rotor, or build up of heavy debris on the screen basket, with only a minimal wear of the screen basket.
Prior to such modifications, plugging of the rotor and consequently of the screen was a regular occurrence and an attempt to overcome the problem by shutting off the ends of the passageway through the rotor only lead to excessive wear of the screen basket. The tertiary screen filter 100, modified as described herein, is now considered to operate satisfactorily in contrast to the generally unsatisfactory operation prior to such modifications.
SUMMARY OF DISCLOSURE
In summary of this disclosure, the present invention provides a modification to a recirculating slurry filter which enables improved operation to be achieved. Modifications are possible within the scope of this invention.
|
Aqueous slurries of particulate materials, particularly wood pulp slurries produced during the recycling of newsprint and other paper products, are processed to recover an accepts fraction in a rotary filter having a hollow cylindrical rotor. The rotor is modified to prevent plugging by outwardly tapering the inner wall of the rotor from its upstream towards a downstream end, so as to cause heavy particles tending to accumulate on the wall to flow towards the downstream end and not accumulate. At the downstream end, vane-like hub supports are provided angularly offset from the axis of the rotor to impart motion to the slurry passing through the rotor to assist in circulation of the slurry within the filter housing.
| 3
|
BACKGROUND
The present disclosure relates to transport of print media and particularly print media in sheet form as is employed in photocopiers and office printers. The disclosure particularly relates to digital image printing in print engines arranged for parallel processing, as for example, printing in plural print engines and for duplex printing on both sides of a print media sheet.
In print engines arranged for parallel processing, it is often the case that the transport of sheet print media will by-pass one or more print engines in order to print concurrently on another print engine. However, the transport path must also include a provision for reversing the direction and movement of the sheet print media for duplex printing. Thus, the transporters propelling the sheets for moving the sheet print media through the designated path must provide for bi directional movement. Heretofore, such bi directional print sheet media movement has been provided by individual transporters disposed in the media path with one transporter arranged to provide print sheet media movement in a forward direction such as for bypass and simplex printing, and another transporter disposed to arrange for print sheet media movement in the reverse direction such as for duplex printing. The transporters are typically each comprised of a series of nip rollers driven by a belt powered by an individual single direction of rotation drive motor. Thus, the functionality of bi directional print sheet media movement in a print engine has been somewhat complex and costly because of the need for plural print sheet media transporters.
It has therefore been desired to reduce the complexity and cost of a sheet transport digital print engine arrangement for parallel printing employing bypass capability and providing for duplex printing on opposite sides of print sheet media.
BRIEF DESCRIPTION
The present disclosure describes a print sheet media transporter for providing movement of sheets through a transport or printing path and particularly for bi directional transport in digital print engines. The single bi directional transporter employs a single drive motor rotating in one direction for driving a belt which is connected to a plurality of spaced drive rolls, each of which has idler rolls disposed on opposite sides thereof for rotating the idler rolls in opposite directions. The combination of the drive roll and oppositely disposed idler rolls forms a pair of nips which are capable of propelling the print sheet media in opposite directions when fed to the oppositely disposed nips. The bi directional print transporter of the present disclosure thus replaces two separately driven unidirectional print sheet media transporters thereby reducing the complexity and cost of the equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a digital printing arrangement with multiple print engines and illustrates the path of movement of the print sheet media for both printing and bypass transport;
FIG. 2 is a perspective view of the bi directional transporter of the present disclosure;
FIG. 3 is a perspective view of the transporter of FIG. 2 taken from the back or motor drive side thereof;
FIG. 4 is a view illustrating the bi directional paper paths through the transporter of FIG. 2 ;
FIG. 5 is a perspective view of two of the drive rolls and associated oppositely disposed idler rollers of the transporter of the present disclosure;
FIG. 6 is an enlarged detailed view of one of the drive rolls and idlers of FIG. 5 ;
FIGS. 7A and 7B are view similar to FIG. 6 showing the unidirectional nip arrangement of prior art print sheet media transporter;
FIG. 8 is a view similar to FIG. 1 showing the arrangement of the plural unidirectional print sheet media transporters of the prior art equipment;
FIG. 9 is a side view of the transporter of the present disclosure with the idler roller deck shown open; and,
FIG. 10 is a perspective view of the transporter of FIG. 9 in the open condition.
DETAILED DESCRIPTION
Referring to FIG. 8 , a known arrangement for a digital print engine is indicated generally at 1 and includes an incoming print sheet media path for the printing function in the engine 1 as denoted by the dashed line adjacent the black arrow 2 . The engine 1 includes a print media sheet bypass path indicated in dashed outline adjacent the black arrow 3 for bypassing the engine 1 and transporting the print sheet media outwardly through the discharge rollers 4 . For the printing function, the print sheet media is processed through the print engine and is subsequently fed along the path indicated in dashed outline adjacent the black arrow 5 . The print engine may include multiple print heads or photoreceptors indicated generally at 6 for marking primary colors to effect color printing. Upon completion of the printing function and movement along the path in the direction indicated by the arrow 5 , the print media is discharged through the rollers 4 in the case of simplex printing. For effecting duplex printing, the print sheet media is transported along the path shown in dashed outline in a reversed direction as indicated by the adjacent black arrow 7 for recycling through the path 2 and printing on the opposite side of the print sheet media. The transporters for effecting the movement of the print sheet media in either the printing or transport mode are shown in the box 8 which contains a plurality of transporters 9 , 10 arranged serially, with one of the transporters 9 operative for effecting movement of the print sheet media in the forward direction as denoted by the dashed arrow 11 . Whereas, the separate transporter 10 is operative for effecting movement of the print sheet media in the reverse direction indicated by the dashed arrow 12 for effecting duplex printing. Each of the transporters 9 , 10 has its own individual drive motor denoted 17 , 18 respectively.
Referring to FIG. 7A , the nip roller drive arrangement of the prior art transporter 9 of FIG. 8 is shown wherein the belt driven drive roll 13 cooperates with an idler roller 14 for propelling the print sheet media (paper) in the forward direction.
Referring to FIG. 7B , the nip roller arrangement of the prior art transporter 10 of FIG. 8 is shown wherein a motor driven drive roll 15 cooperates with an idler roll 16 for propelling the print sheet media (paper) in a reverse direction.
Referring FIG. 1 , a digital print engine indicated generally at 20 according to the present disclosure is operative to receive print sheet media from a sheet feeder (not shown) through entrance nip rollers 21 along a path indicated by dashed line adjacent the dashed black arrow 22 for feeding paper through the print engine and outputting the paper along the path indicated by the dashed outline denoted by the dashed black arrow 26 . The print engine 20 may include plural print heads or photoreceptors for color printing as indicated generally at 24 . The paper may either be discharged through the nip rollers 28 in the case of simplex printing or sent along a reverse path indicated by the dashed black arrow 30 and recycled along the path adjacent arrow 22 for duplex printing on the opposite side of the paper. The print engine 20 also includes a path for bypassing the printing function along a dashed outline path adjacent the black arrow denoted 32 wherein the paper proceeds directly from the inlet to the discharge rollers 28 . The print engine 20 has the single transporter enclosed in a dashed box indicated generally at 34 which is operative to effect the bi directional movement of the paper feed with a single drive motor 36 illustrated in FIG. 1 in the reduced size perspective view of the transporter 34 .
Referring to FIG. 2 , the bi directional transporter 34 of the present disclosure is shown with one single direction of rotation drive motor 36 for effecting the bi directional movement of the print sheet media through the mechanism.
Referring to FIG. 3 , the transporter 34 is shown in perspective view from the motor side with the cover removed to show the motor drive shaft 40 with a belt 42 engaged therewith for driving shaft pulleys 44 , 46 respectively. A second belt 47 is disposed over shaft pulley 46 and a third spaced shaft pulley 48 .
Referring to FIGS. 3 , 5 , 9 and 10 , the motor 36 of the bi directional transporter 34 is mounted on a plate 52 attached to a platform or deck 54 upon which the shafts driven by pulleys 44 , 46 , 48 are mounted. The shaft pulleys 46 , 48 respectively connected to drive shafts 56 , 58 which have mounted respectively thereon a plurality of axially spaced drive rolls 60 , 62 .
Each of the drive rolls 60 , 62 has disposed on opposite sides thereof idler rolls denoted respectively 62 , 64 for shaft 56 and 66 , 68 for shaft 58 . One set of idler rolls for shaft 58 is shown in greater detail in FIG. 6 in which the black arrows indicate the path of the bi directional paper feed.
The transporter 34 may have a modular construction wherein the idler rollers 64 , 68 for shafts 56 and 58 respectively and similarly for idler rollers provided on the shaft connected to pulley 44 are mounted on an upper platform 70 . The idler rollers 62 , 66 and similar idler rollers for the shaft 44 are mounted on a lower platform or deck 72 which platforms 70 , 72 may be opened from the drive roll deck 54 for jam clearance.
The present disclosure thus describes a bi directional feed sheet print media transporter which provides the bi directional movement of the print sheet media with only a single drive motor rotating in one direction. The transporter of the present disclosure thus provides less complexity and lower cost for a digital print engine employing sheet print media where bi directional sheet transport is required.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
|
A method and apparatus for bi-directionally transporting sheet stock in a marking engine by disposing idler rolls on opposite sides of a drive roll on movable idler roll decks for forming forward and reverse nips and feeding sheets from opposite directions into the nips and providing for moving the idler rolls away from opposite sides of the drive roll for jam clearance.
| 1
|
PRIOR ART
Patterning devices are known which produce jacquard-patterned knitted pile fabrics on crocheting galloon machines and which comprise a row of slide needles, a bar providing eye-pointed or feed needles for delivering knitting threads to the slide needles, at least one filling bearing, horizontally and vertically adjustable pile thread guides having several thread emerging openings situated in parallel to the longitudinal axis of the needles, one thread-selecting plate bar or sinker for each pile thread guide, the end of which that is adaptable to the thread emerging openings of the pile thread guide being provided with a thread "neck" for choosing the patterning pile thread and a vertically movable bar whereon all thread selecting plate bars are hingedly positioned and are lockable in a number of tilting or swinging positions which correspond to the number of thread emerging openings of the pile thread guide (German Pat. No. 119,275, U.S. Pat. No. 4,031,717). With the aid of this device, the pile threads tied up in a first wale are transported to the adjacent needle by means of the pile thread guide and the thread selecting plate bar lays only the pile thread intended for patterning, into the needle head of this needle. The patterning pile thread is developed by stitching it with the knitting thread during the return of the needle, while the nonpatterning pile threads remain tied up in the first wale as a so-called stationary filling or weft. In the following machine run, the pile thread guide is set back by two needle divisions and lowered to the level of the needle which makes it possible to bind the patterning pile thread which was selected during the first machine run by the thread selecting plate bar, again into the first wale. Since a pile sinker in the form of a plate bar is situated between the two indicated needles, the respective patterning pile thread is formed into a pile loop.
The disadvantage of the just described device, however, is that when more than two pile threads are used per wale, no reliable selection of the patterning pile thread can be achieved. Due to the fact that the pile threads not intended for patterning assume a not exactly defined flow extending from the last binding place in the fabric up to the respective emerging opening of the pile thread guide, adverse conditions occur; for instance, during the selection of the pile thread coming from the innermost emerging opening of the pile thread guide, which thread is intended as a patterning pile, the pull exerted upon the patterning pile thread, selected by the thread selecting sinkers, can sometimes cause the pile threads not intended for patterning to reach the vicinity of the open hook of the needle and becomed meshed together.
This negative effect increases with the increase in threads to be employed since, in such a case, a piercing of individual capillaries by the hook of the needle suffices to produce patterning errors or thread breakages.
OBJECT OF THE INVENTION
It is therefore, an object of the invention to eliminate such functioning disruptions and to increase the productivity as well as the patterning capacity of the machine.
DESCRIPTION OF THE INVENTION
The invention is based on the objective to provide in a patterning device constructed in the known manner, a reliable selection of the patterning pile thread and to make the described patterning device suitable for operating with more than two pile threads per wale.
To this end and in accordance with the invention, the thread selecting sinker is provided with at least one edge which diverts the non-patterning pile threads from the shaft of the needle that loops the patterning pile threads, the vertical range of movement of this edge reaches from the emergence of the ends of the pile thread guide located in its uppermost position, to the lower edge of the needle, while the horizontal range of movement of the edge reaches from one emerging opening of the pile thread guide up to the immediately adjacent thread emerging opening.
In accordance with another feature of the invention, the number of such edges corresponds to the number -- reduced by " 1" --of the thread emerging openings of the multiple pile thread guide.
In another embodiment of the invention, the non-patterning pile thread diverting edges are situated in unilaterally open recesses which are disposed between the thread neck and the side of the thread selecting sinker facing away from the filling placer.
In accordance with yet another feature of the invention, the side of the thread selecting sinker which faces away from the filling placer is provicded with the diverting edge.
EMBODIMENT EXAMPLE OF THE INVENTION:
The invention will now be described with reference to the accompanying drawing, wherein:
FIG. 1 is a partial cross-sectional view through a crocheting galloon machine provided with the patterning device of the invention;
FIG. 2 is a partial top view upon the stitch forming elements of the crocheting galloon machine provided with the patterning device of the invention, according to FIG. 1;
FIG. 3 is a section along line 3--3 of FIG. 2, in a reduced scale;
FIG. 4 is a section along 4--4 of FIG. 2, in a reduced scale;
FIG. 5 is the front view of the stitch forming elements of FIG. 2 in an enlarged scale; and
FIG. 6 is a side view of another embodiment of the thread selecting sinker of the invention.
The crocheting galloon machine is equipped with horizontally movable slide needles 1, controlled in a known manner by the taken-up loops, alone (see U.S. Pat. No. 4,043,153). The slide needles 1 are guided in the knocking over comb 2 and pass between the pile sinkers 4 which are affixed along the stationary bar 3 and are pointed downwardly. Directly ahead of the pile sinkers 4, are the multiple pile thread guides 5, disposed in a bar 6. The bar 6 is movable vertically as well as laterally in the direction of the row of needles as indicated by arrow A 1 . The thread emerging openings 7a, b, c of the pile thread guides 5 are disposed in an approximately horizontal plane. Above each multiple pile thread guide 5, one thread selecting sinker 9, respectively, is disposed on a guide bar 8 which is movable only in vertical direction. Each thread selecting sinker 9 is situated in its upper position above the multiple pile thread guide 5. The thread selecting sinker 9 is hingedly positioned intermediate its ends on the bar 8, so that its lower end with the thread neck 10 can be selectively coordinated to (disposed over) one of the thread emerging openings 7a, b, c, of the multiple pile thread guide 5 to lay the thread therefrom over the respective slide needle.
Known sinker positioning means are provided comprising spring biased positioner elements P having cam surfaces C disposed on appropriate mounting means M and which are rotatable to operate positioning arm A against spring S to position sinker 9, and lock members L 1 and L 2 cooperate to stabilize the pattern position of the sinker.
For a reliable selection of the desired patterning pile thread, the thread selecting sinker 9 is also provided with two edges 11, 12 which, if necessary, divert the non-patterning pile threads from the shaft of the needle 1 which loops the patterning pile threads. As the sinker 9 is depressed to loop the patterning pile, the vertical extension of the edges 11, 12 reaches during this time, from the emerging openings 7 of the pile thread guide 5 situated in its uppermost position, up to the lower edge of the needle and the horizontal extension reaches from one of the emerging openings 7a, 7b or 7c up to the immediately adjacent emerging opening.
It is noted that in the apparatus disclosed, the conventional warp thread layering member 13 and the filling thread layering member 14 are also provided, for producing the goods (FIG. 1).
In another embodiment of the thread selecting sinker 9a (FIG. 6), the diverting edge 12a is shortened in its horizontal and vertical extension on the side of the thread selecting sinker 9a that is facing away from the filling thread layering member 14. In order to avoid piercing the capillaries of the pile threads, the junction between the thread neck 10 and the directly adjacent recess of the thread selecting sinker 9 which contains the diverting edge 11a, is made round. Likewise, the junction between said recess and the edge 12a is also rounded and edge 12a is reduced in size; i.e. shortened.
At the start of the work cycle, the lower end of the thread selecting sinker 9 with the thread neck 10, may be located above the thread emerging opening of the desired patterning pile thread, for example thread emerging opening 7a, whereby the pile thread guide is in its raised position. The guide bar 8 sinks downward and the thread selecting sinker 9 grasps with its thread neck 10 the pile thread which, in this instant, comes from the thread emerging opening 7a, and presses the same on the shaft of the appropriate needle 1. During the return of the needle 1, this pile thread is then formed into a loop, while the pile threads which stem from the thread emerging openings 7b and 7c are not looped as they have not been pressed on the shaft of the needle.
If the pile thread coming from thread emerging openings 7b is to be looped, then the thread selecting sinker 9 stands with its neck 10 above the thread emerging opening 7b and presses the appropriate pile thread upon the shaft of the appertaining or coordinated needle 1. The pile thread coming from thread emerging opening 7a slides thereby, during the lowering of the thread selecting sinker 9, along the edge 11 into the recess of the thread selecting sinker 9, which assures the prevention of the pull exerted by the thread selecting sinker against the patterning pile thread, causing the pile thread coming from the thread emerging opening 7a to reach the vicinity of the needle hook 1 and become looped (FIGS. 2, 3 and 5).
If, however, the pile thread stemming from the thread emerging opening 7c is to be looped, the thread selecting sinker 9 with its neck 10 will be positioned above the thread emerging opening 7c and press the respective (appropriate) pile thread upon the shaft of the coordinated needle 1. The pile thread coming from thread emerging opening 7b slides thereby, during the lowering of the thread selecting sinker 9, along the edge 11 into the recess of the thread selecting sinker 9 and the pile thread which comes from the thread emerging opening 7a slides thereby, during the lowering of the thread selecting sinker 9, upwardly along edge 12 into the recess of the thread selecting sinker 9. As a result, the pile thread coming from the thread emerging opening 7a as well as the one coming from the thread emerging opening 7b, is diverted upwardly and sideways from the shaft of the respective needle 1 so that, with reliability, only the pile thread intended for patterning will be grasped by the hook during the return of the needle and become looped (FIGS. 2, 4 and 5).
|
The invention produces jacquard-patterned knitted pile fabrics on pile knitting machines, more particularly crocheting galloon machines in which sinkers for reliably selecting respective patterning pile thread are provided together with non pattern thread diverting surfaces.
| 3
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The subject invention is directed to a system and method for determining the buying power of an investment portfolio, and more particularly, to a system and method of determining a purchasing limit for a proposed transaction involving a financial instrument.
[0003] 2. Background of the Related Art
[0004] Investment managers, and in particular, those who are responsible for managing the portfolios of large institutional investors, buy and sell fixed income securities and equities, based upon the investment objectives set forth by the investors. For example, a particular institutional investor may wish to restrict certain types of assets from its portfolio. In such an instance, the investor may instruct its portfolio manager not to purchase corporate bonds or equities from certain corporations or industry sectors. Alternatively, a particular institutional investor may have the desire to limit a certain percentage of its assets under management to certain types of fixed income securities. For example, an institutional investor may designate that not more than five percent of its assets under management should be invested in agency-backed securities.
[0005] Investment objectives are generally conveyed from an investor to a portfolio manager in the form of a set of investment rules or guidelines. The investment rules are then used by the portfolio manager to develop compliance rules against which investment decisions or portfolios of investments are analyzed.
[0006] Compliance rules operate in two distinct ways. First, a compliance rule can affect a particular investment decision, such as the decision to purchase a large quantity of Treasury notes for inclusion in a particular portfolio. This decision could be governed by one or more compliance rules that would influence the decision before the investment is made. Such a rule is commonly referred to as a “front end” compliance rule. Alternatively, a compliance rule could affect the composition of a particular portfolio, such as by requiring a portfolio manger to sell a quantity of a particular type of fixed income security. For example, as a result of a change in interest rates, a compliance rule may be employed to instruct a portfolio manager to reduce the quantity of a certain class of Treasury notes within a particular portfolio. Such a compliance rule would affect the portfolio as a whole, rather than a particular investment decision, and is therefore commonly referred to as a “back end” compliance rule.
[0007] Compliance rules, whether related to front-end or back-end compliance, have been used by portfolio managers in computerized portfolio management systems. In the past, compliance rules set forth by institutional investors have been translated into computer readable statements. Such statements are then used to instruct a computer system to monitor investment decisions and the composition of portfolios as a whole, and to inform portfolio mangers whether particular investment decisions or portfolios of investments are in compliance with the investment objectives of particular investors. In this case, compliance rules are used to provide portfolio managers with information concerning purchasing limits for proposed transactions.
[0008] More particularly, prior to executing a trade involving a financial instrument, a portfolio manager will typically be interested in knowing the purchasing limit or buying power for a particular portfolio, or for a group of portfolios. That is, the portfolio manager would like to know how much of a particular financial instrument can be purchased for a given investment portfolio, without violating any compliance rules or limits, before the trade is executed. Without this information, a portfolio manager could enter a transaction request for a quantity of securities that may be in excess of a certain limit placed on the portfolio by the compliance guidelines. In such an instance, the portfolio manager would have to modify the transaction request so that it is acceptable. Without guidance from the system, this could take several attempts, making the task extremely inefficient. It would be beneficial therefore to provide a portfolio manager with transaction limit information, based upon compliance rules, prior to the execution of a trade to enable the manager to efficiently allocate available funds among one or more portfolios.
SUMMARY OF THE INVENTION
[0009] The subject invention is directed to a new and unique method of determining the buying power of an investment portfolio. The method basically includes the steps of providing a set of compliance rules for an investment portfolio, and applying the set of compliance rules to a proposed transaction to determine a transaction limit therefor. The proposed transaction preferably includes a financial instrument, and more preferably a fixed income security, such as, for example, Treasury bonds and notes, mortgage-backed securities, agency backed securities, etc. The compliance rules are generally based on portfolio guidelines defined by the investor and regulatory requirements imposed by a governmental entity.
[0010] In accordance with a preferred embodiment of the subject invention, the method includes the steps of providing a set of compliance rules for an investment portfolio, receiving a request to analyze a proposed transaction, and calculating a transaction limit for the proposed transaction based upon the set of compliance rules. Preferably, the step of calculating a transaction limit includes calculating a transaction limit for each compliance rule, and the method further comprises the step of sorting the compliance rules from most restrictive to least restrictive based upon the transaction limit calculated for each compliance rule. The method further includes the step of determining the buying power of the portfolio based upon the transaction limit associated with the most restrictive compliance rule. Preferably, the method further includes the step of determining whether the each compliance rule applies to the proposed transaction by testing each rule against the proposed transaction using a nominal transaction value, for example, one dollar. The invention further includes the step of determining that the buying power of the portfolio for the proposed transaction is zero if the nominal transaction value for the proposed transaction violates a compliance rule.
[0011] The subject invention is also directed to a system for determining the buying power of an investment portfolio. The system includes means for storing a set of compliance rules for an investment portfolio, means for receiving a request to analyze a proposed transaction, and means for calculating a transaction limit for the proposed transaction based upon the set of compliance rules. Preferably, the means for calculating a transaction limit is adapted and configured to calculate a transaction limit for each compliance rule, and the system further includes means for sorting the compliance rules from most restrictive to least restrictive based upon the transaction limit calculated for each compliance rule. Means are also provided for determining the buying power of the portfolio based upon the transaction limit associated with the most restrictive compliance rule. Additionally, the system includes means for determining whether each compliance rule applies to the proposed transaction, which means are adapted and configured to test each compliance rule against the proposed transaction using a nominal transaction value.
[0012] The subject invention is also directed to a method of determining the buying power of an investment portfolio that includes the steps of receiving a request to analyze a proposed transaction involving a security from a portfolio manager for a selected portfolio stored in a portfolio database, retrieving the selected portfolio from the portfolio database and accessing a set of compliance rules related to the selected portfolio from a rules database. The method further includes the steps of determining whether each compliance rule in the set of compliance rules related to the selected portfolio applies to the proposed transaction, calculating a transaction limit for the proposed transaction for each applicable compliance rule in the set of compliance rules and sorting each applicable compliance rule from most restrictive to least restrictive. The method further includes the step of specifying the buying power of the selected portfolio for the proposed transaction based on the transaction limit for the most restrictive of the applicable compliance rules.
[0013] These and other aspects of the system and method of the subject invention, including the ability to improve the buying power of a selected portfolio, will become more readily apparent to those having ordinary skill in the art from the following detailed description of the invention taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] So that those having ordinary skill in the art to which the present invention pertains will more readily understand how to make and use the method and system of the present invention, embodiments thereof will be described in detail hereinbelow with reference to the drawings, wherein:
[0015] FIG. 1 is a schematic diagram depicting the core functional components of the portfolio management system of the subject invention;
[0016] FIG. 2 is an illustration of a graphical display screen configured in accordance with a preferred embodiment of the subject invention; and
[0017] FIG. 3 is a process flow chart illustrating the iterative steps of a method configured in accordance with a preferred embodiment of the subject invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] Referring now to the drawings wherein like reference numerals identify similar elements or aspects of the system and method disclosed herein, there is illustrated in FIG. 1 a schematic representation of a computer-based portfolio management system constructed in accordance with a preferred embodiment of the present invention and designated generally by reference numeral 10 . Portfolio management system 10 features trade entry and portfolio management tools and is integrated with compliance and risk management modules. As described below, system 10 includes software and hardware arranged in a distributed computing network, including programs, operating systems, memory storage devices, input/output devices, data processors, servers with links to data communication systems, wireless or otherwise, such as those which take the form of a local or wide area network, and a plurality of data transceivers within the network.
[0019] Referring to FIG. 1 , portfolio management system 10 basically includes a graphical user interface 12 that interacts with a control program 14 associated with a data storage device or memory 16 and an analytical server 18 that comprises a plurality of processors 20 . The graphical user interface 12 is a data input/output device that incorporates user-friendly features presented on a display screen in a framed form having borders, multiple folders, toolbars with pull-down menus, embedded links to other screens and various other selectable features associated with animated graphical representations of depressible buttons. These features can be selected (i.e., “clicked on”) by the user via connected mouse, keyboard, and voice command or other commonly used tools for indicating a preference in a computerized graphical interface. The control program 14 contains an instruction set written in a conventional computing language such as HTML, C++ or Java, for coordinating the interactive relationship between graphical user interface 12 , memory 16 and the processors 20 of analytical server 18 .
[0020] In accordance with a preferred embodiment of the subject invention, the memory 16 contains a plurality of cooperative relational databases, including a portfolio database 22 , a rules database 24 and a securities database 26 . The portfolio database 22 stores a plurality of investment portfolios owned by individual or institutional investors. Each portfolio includes a plurality of investment products in the form of fixed income securities such as U.S. Treasury notes or bonds, municipal, corporate or agency bonds, mortgage backed securities or derivative instruments.
[0021] Rules database 24 stores a multiplicity of front-end and back-end compliance rules related to the portfolios stored in the portfolio database 22 . The compliance rules may relate to, among other things, duration guidelines indicating a targeted duration for a portfolio, asset allocation guidelines setting forth eligible types of investments, credit agent criteria for financial instruments (e.g., ratings supplied by S&P or Moody's), restricted securities which may not be added to a portfolio and other investment practices. Securities database 26 maintains the identifying and descriptive information about a security, including, for example, original issuer information, coupon/factor data, put/call information, cash flow data and payment processing information.
[0022] Referring now to FIG. 2 , there is illustrated a detailed illustration of a display screen of the graphical user interface 12 configured in accordance with a preferred embodiment of the subject invention and designated generally by reference numeral 100 . Display screen 100 serves as the control panel or “dashboard” for the trade entry system of portfolio management system 10 . The trade entry system, within which the “buying power” module of the subject invention is incorporated, is designed to maximize the quantity of information captured at trade time through the display screen 100 by adjusting for different security types and defaulting the value of certain data fields to minimize data input by portfolio managers.
[0023] The trade entry system retrieves security information from the securities database 26 to populate the various field of display screen 100 . For example, the following fields may be automatically populated with information from securities database 26 upon entry of the Asset ID or CUSIP in field 102 and transaction type in field 104 : security description (name, coupon and maturity date) in field 106 ; trade date in field 108 ; settlement date (defaults to convention based on security type) in field 110 ; price, yield, duration and convexity (defaults to previous end of day) in fields 112 , 114 , 116 and 118 , respectively; trading desk and broker in fields 120 and 122 , respectively. It is envisioned that display screen 100 could be modified to present additional information stored in the securities database 26 , including, for example, factor, principal, interest, net money, and current par.
[0024] With continuing reference to FIG. 2 , display screen 100 includes a portfolios table 124 containing information relating to portfolios stored in database 22 such as the portfolio name, duration, trade quantity, trade number, % NAV, buying power limit “BP Limit” and trade status, as well as commission information. Display screen 100 also provides access to several drop down boxes through a set of horizontally disposed click tabs spread across the viewing screen. For example, click tab 130 provides access to trade information, click tab 132 provides access to comments entered by a user, click tabs 134 and 136 provide access to information relating to security and analytics. Click tab 140 provides access to information concerning the “buying power” of a selected portfolio. In accordance with the subject invention, the buying power module enables a portfolio manager to determine a dollar limit or quantity for a proposed transaction involving a security using the compliance guidelines stored in the rules database 24 for a selected portfolio or group of portfolios stored in portfolio database 22 .
[0025] The buying power selection tab 140 opens a list box 142 that displays buying power information including a sorted list of compliance rules from rules database 24 which affect the buying power of a selected portfolio and the purchasing limit in dollars established by the rule. A rule description box 144 is located adjacent to the buying power message box 142 under buying power tab 140 that provides the detailed character strings that define each of the applicable compliance rules set forth in message box 142 to enable the portfolio manager to better understand the basis for the compliance rule.
[0026] Referring now to FIG. 3 , there is illustrated a process flow chart 200 depicting the iterative steps employed by the system to determine the buying power of a selected portfolio or group of portfolios in accordance with a preferred embodiment of the subject invention. In describing the process steps of flow chart 200 , reference will be made to the data presented in display screen 100 of FIG. 2 . Initially, at step 210 , the system receives a request to analyze a proposed transaction from a portfolio manager involving a fixed income security for a selected portfolio stored in database 22 , often referred to as a “what if” scenario analysis. For example, as shown in FIG. 2 , the portfolio manager enters a proposed buy request in field 104 for an asset backed security “ABS” referred to as “SCCMT — 94-2” in field 106 with an Asset ID designated in field 102 as “85333JBE6” in the amount of $11,192,000, for inclusion in a portfolio called “TGT-C”. The transaction amount is presented in the quantity column of portfolios table 124 . At such a time, the default fields of display screen 100 are populated with information from securities database 26 , including a price of $113.00, a yield of 2.886%, a duration of 2.627 and a convexity of 0.099, as displayed in fields 112 , 114 , 116 and 118 , respectively.
[0027] At step 220 , the system retrieves the selected portfolio from portfolio database 22 for use in the buying power calculation/determination. Then, at step 230 , the system accesses rules database 24 to retrieve the compliance rules associated with the selected portfolio. As shown in FIG. 2 , there are two compliance rules in message box 142 related to portfolio TGT-C. The first compliance rule relates to single issuer allocation, and more particularly, provides that securities from a single issuer must be less than or equal to 5% of the total value of the portfolio, unless the security is a Treasury, Agency or Government security. The second rule relates to sector allocation, and more particularly, provides that the value of asset backed securities must be less than or equal to 25% of the total value of the portfolio.
[0028] At step 240 , the system determines whether the compliance rules for the selected portfolio apply to the proposed transaction. More particularly, the system runs a subroutine 245 , which, at step 250 , applies each compliance rule associated with the selected portfolio to the proposed transaction using a nominal value, e.g., one dollar. At step 260 , the system determines whether the proposed transaction would violate a compliance violation based on the nominal transaction value. If there is a compliance violation using the nominal value, the system will indicate that the buying power of the selected portfolio for the proposed transaction is zero at step 270 . Alternatively, if each of the compliance rules associated with the selected portfolio are not violated by the proposed transaction and thus are applicable thereto, the system advances to step 280 to calculate the transaction limit for each applicable rule.
[0029] The methodology employed to calculate a transaction limit will vary depending upon the type of compliance rule. For example, if appropriate, the system can conduct an iterative hunt and peck routine, whereby after testing the nominal value against a compliance rule, the proposed transaction will be applied against the compliance rule using a value equal to the total available asset value of the selected portfolio. If that test does not result in a violation, then there would be no limit for the proposed transaction. Alternatively, if the total asset value test described above results in a compliance violation, the system will incrementally change the test value until the transaction limit is approached and obtained.
[0030] In other instances, where appropriate, the transaction limit can be calculated based on a percentage of the total asset value of a portfolio. For example, referring to FIG. 2 , the transaction limit for the single issuer allocation rule is $2,854,607.10. That is, based on the total asset value of portfolio TGT-C, no more than $2,854,607.10 of the analyzed asset backed security SCCMT — 94-2 can be added to the selected portfolio TGT-C. Similarly, the transaction limit for the sector allocation rule is $11,192,739.43. Thus, based on the total asset value of portfolio TGT-C, no more than $11,192,739.43 of the asset backed security SCCMT — 94-2 can be added to the selected portfolio TGT-C.
[0031] After the transaction limits for each applicable compliance rule are calculated at step 280 , the applicable compliance rules are sorted at step 290 in order from most restrictive to least restrictive based on transaction limits. Thus, as shown in message box 142 , the single issuer allocation rule is more restrictive than the sector allocation rule. This is apparent in the fact that the transaction limit for the single issuer allocation rule is less than the transaction limit for the sector allocation rule.
[0032] Finally, at step 300 , the system specifies the buying power for the selected portfolio based on the transaction limit for the most restrictive rule. In this case, as shown in the portfolios table 124 , the buying power for portfolio TGT-C, with respect to the proposed transaction involving the asset backed security SCCMT — 94-2, is $2,854,607.10, which is the transaction limit for the most restrictive compliance rule shown in message box 142 .
[0033] Once the portfolio manager determines the buying power for the portfolio with respect to the proposed transaction, the transaction may be executed though the trade entry system if that is desired. However, if the portfolio manager desires to increase the buying power of the portfolio for the proposed transaction, they can use the information provided by message box 142 and rules description box 144 to obtain an in depth understanding of the basis for the buying power determination. For example, the sector allocation rule description presented in box 144 indicates that in its current state, 5.4% of the total asset value of portfolio TGT-C is represented by asset backed securities, making the transaction limit 19.6% of the total asset value of the portfolio. Thus, using the rules descriptions, the portfolio manager can see why the transaction limit was calculated, which would allow them to identify alternative opportunities and decide what actions to take, so as to maximize the quantity of the analyzed security that can be purchased. The information will enable the portfolio manager to modify or adjust the composition of the portfolio to increase buying power for the desired transaction.
[0034] For example, in the case of the proposed transaction illustrated in FIG. 2 , if the selected portfolio contained less desirable SCCMT securities of a different rate and maturity than the more desirable SCCMT — 94-2 securities targeted by the proposed transaction, the portfolio manager could sell the less desirable securities to increase the buying power of the portfolio for the more desirable securities. Similarly, if the more restrictive rule was a sector allocation rule, the portfolio manager could sell off less desirable securities within the restricted sector to make room for more desirable securities, thereby increasing the buying power of the portfolio.
[0035] Although the system and method of the subject invention have been described with respect to preferred embodiments, those skilled in the art will readily appreciate that changes and modifications may be made thereto without departing from the spirit and scope of the subject invention as defined by the appended claims.
|
A system and method for determining the buying power of an investment portfolio are disclosed which involve providing a set of compliance rules for an investment portfolio, receiving a request to analyze a proposed transaction, and calculating a transaction limit for the proposed transaction based upon the set of compliance rules.
| 6
|
TECHNICAL FIELD
[0001] This invention relates to a curvilinear spa, and more particularly to curvilinear spa frame design to support a curvilinear spa shell.
BACKGROUND
[0002] Typical spas are designed around dimensional lumber and are usually very linear in shape. Some deviations do occur in certain models but only on one or two sides. Spas with very linear shell shapes require very linear frames that are easily constructed with dimensional lumber, like 2×4's or 2×2 lumber.
[0003] Typical linear spas are very plain looking, especially when the cover is on and they are not in use. Linear spas are not architecturally pleasing and cannot in and of themselves become a focal point for the customers' landscape architecture. Accordingly, many spa owners hide their spas with landscaping or put them inside structures such as gazebos.
[0004] It is therefore advantageous to provide the customer with a spa shell that is curvilinear in shape so that the spa is not just a box of hot water. A spa shell that has curvilinear sides necessarily requires a frame that among other things will remain square with handling and water pressure and that will fully support the bar top. Current linear spa frame designs are inadequate for a curvilinear spa shell design. A metal frame that follows the entire profile of the curvilinear spa is complex in shape and difficult to manufacture. Additionally, such a frame would be heavy. As a result, the cost associated with such a frame would be excessive.
SUMMARY
[0005] The present curvilinear spa frame invention addresses the need to provide a rigid frame to support a curvilinear spa shell design. The present invention includes a frame comprised of a bottom plate of shaped plywood or similar support material, to which can support a multiplicity of box sections aligned to be within the confines of the spa shell curves and provide stiffness for the completed frame in all directions. Atop these box sections would be affixed a multiplicity of curved pieces that form the top rail of the frame and support the spa bar top. The box sections can be given greater rigidity by the use of truss plates and associated assembly, by the use of sheet material as a stiffener or by any other fasteners.
[0006] In another embodiment of the present invention, sheet material can be used in conjunction with corresponding notches in the curved components to align the top and bottom of the frame.
[0007] The present invention provides a frame that will remain square regardless of handling and water pressure while fully supporting the bar top of the spa. It is another advantage of the present invention to fully support a curvilinear spa shell design without complicated frame components that can mimic the curvilinear shape of the bar top. It is yet another advantage of the present invention to have a frame support a curvilinear spa shell design by use of structural box elements that are not as complex in shape as the outline of the curvilinear spa shell. Another advantage of the present invention includes structural box frames that need not follow the entire circumference of the curvilinear spa outline. It is yet another advantage of the present invention that the frame components are easier to manufacture. It is another advantage of the present invention that interlocking sheet material and groove techniques or other known techniques can be utilized to make alignment of the curvilinear spa frame components easier resulting in rapid and reliable assembly and a stronger, more rigid frame. It is yet another advantage of the present invention that the bar top be supported adequately by the curvilinear top rail without necessarily requiring the use of non-standard lumber. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0008] [0008]FIG. 1 is an isometric view of a curvilinear spa.
[0009] [0009]FIG. 2 is an isometric view of a curvilinear spa frame.
[0010] [0010]FIG. 3 is a top view of the top rail of the spa frame.
[0011] [0011]FIG. 4A is an isometric view of another embodiment of the curvilinear spa
[0012] [0012]FIG. 4B is an isometric view of a box section with panel and interlocking groove.
[0013] [0013]FIG. 5 is a box section with truss.
[0014] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0015] [0015]FIG. 1 depicts an embodiment of a curvilinear spa 2 . Curvilinear spa 2 has an inner shell 4 that can hold water and includes support for spa users while experiencing the benefits of hydrotherapy. Bar top 6 substantially follows the contour of the curvilinear spa outline formed in part by the decorative siding 22 .
[0016] [0016]FIG. 2 depicts a curvilinear spa frame 8 that supports the curvilinear spa shell 4 . As depicted in FIG. 2, the curvilinear spa frame 8 includes a top rail 10 and a bottom rail 12 . The top rail 10 and bottom rail 12 substantially mimics the contour of the curvilinear spa 2 . The top rail 10 and bottom rail 12 can be made of any material suitable for supporting the weight associated with the use of the shell 4 , for example, wood, metal, composite materials like fiberglass, etc. The top rail 10 can be substantially the same shape as the bar top 6 and can support the weight associated with the bar top 6 . During assembly, the top rail 10 can be aligned with and become an anchor for the bar top 6 .
[0017] As depicted in FIG. 2, the bottom rail 12 can be supported by a bottom pedestal 14 or similar support structure. The bottom pedestal 14 is used to give additional stability to the frame and like the top and bottom rail, can be made of any material capable of supporting the weight of the spa, like wood, metal, composite materials like fiberglass, etc. For additional rigidity, bottom beam 16 can be secured to the opposing sides of the bottom pedestal 14 . Other similar fastening techniques can be utilized as well to secure the bottom rail 12 , top rail 10 and bottom pedestal 14 in a predetermined manner in order to facilitate assembly and rigidity.
[0018] As shown in FIG. 2, between top rail 10 and bottom rail 12 is a plurality of box sections 18 . Box sections 18 provide rigidity to the frame structure in addition to providing support to the top rail 10 . Box sections 18 are substantially linear and can be spaced intermittently substantially within the confines of the outer diameter of the curvilinear frame 8 thereby alleviating the need for more complex shaped support structures that follow the complex contours of the curvilinear spa frame 8 . Box sections 18 can be prefabricated and made of any material capable of supporting the weight associated with the spa 2 , like metal, wood, composite materials like fiberglass, etc.
[0019] [0019]FIG. 3 depicts a top view of the top rail 10 . Top rail 10 can be formed as one piece, or alternately, can be formed from a multiplicity of pieces, e.g., fabricated using a CNC machine. When the pieces are fastened, the top rail 10 is formed and becomes a structurally sound support member for the bar top 6 (not shown). If a multiplicity of overlapping pieces are utilized to fabricate top rail 10 , glue, staples, or other known fasteners can be used to create an integrated top rail 10 member.
[0020] [0020]FIGS. 4A and B depicts another embodiment of the curvilinear spa frame 8 that is easy to assemble and sufficiently rigid. As seen in FIG. 4A, the box sections 18 include a sheet 24 fastened in any known fashion to a rectangular structural member 26 . As depicted in FIG. 4B, use of the sheet 24 not only improves rigidity, but also assists with alignment of curvilinear spa frame components, e.g., the top rail 10 and bottom rail 12 . As depicted in FIG. 4B, the sheet 24 interlocks into notches in the top rail 10 and bottom rail 12 . As a result, box section 18 can be readily inserted into the appropriate position between top rail 10 and bottom rail 12 thereby facilitating alignment of the top rail 10 and bottom rail 12 . The notches can be located in various combinations of the top rail 10 and bottom rail 12 , as long as the box section 18 assists alignment of the spa frame curvilinear components, e.g., the top rail 10 to the curvilinear bottom rail 12 . Other fastening techniques can be utilized, e.g., predetermined placement of holes in the top and bottom rails with associated pegs on the top and bottom of the box section 12 (not shown). Additionally, strategic use of any modern fasteners, e.g., predetermined placement of pieces of sheet metal also may be used to ensure that corresponding box sections 18 are secured at corresponding predetermined locations in the curvilinear spa frame during assembly, thereby facilitating alignment of the curvilinear spa frame components. Those of skill in the art will appreciate the fact that many different types of interlocking construction can be utilized, e.g., pegs and holes, interlocking sheet material and notches, etc. The interlocking construction can be located on any and/or all curvilinear frame components to improve rigidity and increase ease of assembly. As depicted in FIG. 4A, additional supports 28 , in this case 2×2s, can be included in the curvilinear spa frame 8 as needed to increase rigidity.
[0021] To further increase structural rigidity, FIG. 5 depicts the use of truss plates 20 on box section 18 . If more rigidity is desired, additional truss plates 20 can be added. Typically, truss plates are made of sheets of galvanized steel and are secured into the box sections using pressure during fabrication.
[0022] Moreover, increasing the strength of the box sections 18 may advantageously reduce the number of box sections 18 required to maintain the rigidity associated with the spa 2 . To further reduce the number of box sections 18 required, additional supports 28 as depicted in FIG. 4A can be added.
[0023] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, additional structural members may be added to the curvilinear spa frame 8 to increase rigidity. Moreover, various fastener and bracing technologies can be incorporated into the curvilinear spa frame design, e.g., hangers and plates, angle braces and gussets to brace the fame along various axis, framing connectors, spacers, etc. Such components can be located, for example, between the box sections and the top rail 10 , or alternately between the box sections 18 and bottom rail 12 without departing from the spirit of the invention. Additionally, those of skill in the art will appreciate that depending on the size, shape and strength of each box section, more or less box sections 18 can be included into the curvilinear spa frame than discussed or depicted. Furthermore, box sections can be many shapes and sizes and can have a variety of interlocking mechanisms located on various sections of the spa frame, not just the top rail 10 and/or bottom rail 12 . Accordingly, other embodiments are within the scope of the following claims.
|
A curvilinear spa frame apparatus and method that provides support to a curvilinear spa shell design, including a frame comprising a top curvilinear rail, a bottom curvilinear rail, and one or more box sections aligned to be within the confines of the curvilinear spa shell providing stiffness for the completed frame. The box sections can include sheets that align with corresponding notches in the curvilinear spa frame increasing rigidity and facilitating alignment of the spa frame components during assembly.
| 4
|
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure pertains to slings for carrying and manipulating an object and, more particularly, to a sling adapted for use with firearms to accommodate rapid weapon deployment and use in a variety of tactical environments.
[0003] 2. Description of the Related Art
[0004] Slings are of ancient origin, devised generally of a loop of rope, strap, or a chain for supporting a load. While its history remains unknown, the sling is in widespread use in modern times in connection with a variety of manual and mechanical uses, including baby slings, arm slings, camera slings, musical instrument slings, and weapon slings.
[0005] When used manually, a properly designed sling will distribute the load for balance and comfort, and it will facilitate use of the load. For example, a baby sling holds the baby close to the caregiver in a manner that keeps the caregiver's hands free and avoids back strain while keeping the baby in a position to see the caregiver and be fed and comforted. Slings used for musical instruments are designed for load support and comfort while positioning the instrument so it can be played and, in some cases, so that music can be supported thereon for reading by the carrier.
[0006] Slings for weapons, and in particular rifles, shotguns, and long-barreled weapons, have been designed to provide not only hands-free support, but to facilitate bringing the weapon quickly into a ready-to-use position. Such designs include those disclosed in U.S. Pat. Nos. 3,211,351; 4,823,491; 5,810,219; 5,971,239; 6,260,748; 6,325,258; 6,536,153; 6,598,330; and D495,870.
[0007] One area of concern is accommodating rapid deployment and use, including retraction and retention of a weapon, such as a rifle. While prior slings attempt to address this issue with the use of adjustment devices or multifunctional sling mounts, such approaches can be complex, costly, and time consuming to implement in the filed and in some cases create noise that can interfere with the intended use.
[0008] In the past, designers have incorporated elastic elements into the sling to allow a weapon to be thrust away from the user's body. For example, a single elastic cord has been used, but in order to properly support the weight of the resting weapon, the elastic had to be thick and heavy. This is not preferred because if the elastic cord is too thick it will cut into the user's shoulder or trapezius, resulting in discomfort, possible injury, and inhibiting proper use of the weapon.
[0009] While a sling can incorporate a smaller one piece elastic cord, it will be too small and not support the weapon. The weight of the weapon will cause the elastic cord to stretch out, completely rending the elastic cord useless for its intended purpose. This describes most, if not all, of such type of stretchable slings on the market, which use elastic cord in only one side of the sling; this results in a less than ideal performance because the stretch is neither even nor uniform and in the fraction of a second that a user needs to reach out with the weapon, such as in hand-to-hand combat, the weapon can veer off to one side (the side without bungee) causing the user to miss the intended point of impact.
BRIEF SUMMARY
[0010] In accordance with the disclosed embodiments of the present disclosure, a sling is provided that includes a first strap having an elastic sidewall or tubular webbing enclosing a hollow interior and a pair of elastic cords attached to the strap and located inside the hollow interior of the strap, the first strap further comprising a first connector member on a first end of the first strap; and a second strap having an elastic sidewall or tubular webbing enclosing a hollow interior and a pair of elastic cords attached to the strap and located inside the hollow interior of the strap, the second strap further comprising a second connector member on a first end and releasably connectable to the first connector member of the first strap, the first and second straps each having second ends permanently coupled together.
[0011] As will be readily appreciated from the foregoing, the bungee sling of the present disclosure allows the sling to expand as well as contract in order to provide two completely separate functions:
[0012] Expand: the elastic bungee sling allows the user to evenly and accurately push his weapon away from the user's body (which could not be done with a traditional, fixed/non-bungee sling). Instances of this would be:
[0013] striking an opponent with the barrel or muzzle of the weapon, which helps subdue opponents and encourage compliance with verbal commands,
[0014] striking an opponent with any other part of the weapon, i.e. magazine, grip, etc., which is useful when an opponent is trying to gain control over a user's weapon, and
[0015] lengthening the reach of the weapon to push open a door without the user's body having to get physically closer to the door.
[0016] Shrink/Contract: when stretched or lengthened, the kinetic energy stored up in the lengthened elastic cords inside the sling urges the sling to shrink or contract back to its original length. This is useful to many users because it pulls the weapon back into the user's shoulder, providing a more solid shoulder mount and thus a more accurate shot. Again, this could not be done with a traditional, fixed/non-bungee sling.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0017] The foregoing and other features and advantages of the present disclosure will be more readily appreciated as the same become better understood from the following detailed description when taken in conjunction with the accompanying drawings, wherein:
[0018] FIGS. 1-48 illustrate the steps of a method of making a bungee sling in accordance with the present disclosure:
[0019] FIGS. 49 and 50 are isometric views of male and female buckle components used in the method illustrated in FIGS. 1-48 ;
[0020] FIG. 51 is a pictorial illustration of components used to make the bungee sling of the present disclosure; and
[0021] FIGS. 52A and 52B and pictorial illustrations of the sling supporting a weapon on a user's torso.
DETAILED DESCRIPTION
Cut Sheet
[0022] Part Number/PIN: S1018-X*
[0023] (*X=B (black), G (olive drab), T (coyote tan), or F (foliage green)
[0000]
Material/Item
Qty:
1.25. tubular webbing
35″
1.25. tubular webbing
49″
⅜. elastic cord
4 pieces (8″ lengths)
1.25. triglide
1
1.25. common loop
1
.Patent Pending. label
1
1.25. swivel connector
1
1.25. male QRB (Quick-Release Buckle)
1
1.25. female QRB (Quick-Release Buckle)
1
[0024] Material Identification/Nomenclature:
Procedure
[0025] 1. Cut all necessary pieces and begin below with the longer piece.
[0026] Longer Piece
[0027] 2. Sear one end of the longer webbing piece on both sides.
[0028] 3. Sew in the triglide at the recently seared end with a box X with no less than 6 thread passes at the top and bottom of the box X. The box X should be no longer than ¾ inch.
[0029] 4. Thread the free end through the common loop ( FIG. 4 ). IMPORTANT: It is essential to maintain proper orientation of triglide while threading the common loop!
[0030] 5. Thread the free end back through the triglide ( FIGS. 5-7 ).
[0031] 6. Insert elastic cords (2) into the open/non-seared end of the longer webbing piece. TIP: insert elastic cords into the tubular webbing a .finger length. or approx. 4 inches ( FIG. 9 ).
[0032] 7. Now sear this end (on both sides), sealing the elastic cords into the longer strap.
[0033] 8. Threading the webbing through the female part of the QRB making sure “good side” is facing out ( FIGS. 11-13 ). If needed, reference sample for proper orientation.
[0034] 9. Next, fold webbing under as seen below making sure fold does not exceed ¾ of an inch ( FIG. 14 ).
[0035] 10. Sew in the female part of the QRB with a box X with no less than 6 passes at the top and bottom of the box X ( FIG. 15 ).
[0036] 11. As far as possible, move elastic cords to the end of the strap ( FIGS. 16 & 17 ).
[0037] 12. Bartack elastic cords in place near the end of the strap ( FIGS. 18 & 19 ). TIP: Pinch elastic cords together during the first 2 thread passes to ensure elastic cords stays centered in the tubular webbing.
[0038] Sew two (2) bartacks ¼. apart with a minimum of 6 passes of thread per bartack.
[0039] 13. Mark the strap 8 inches from end of elastic cords ( FIG. 20 ).
[0040] 14. Compress tubular webbing onto the elastic cords (as seen in FIG. 21 ) until the chalk mark reaches the end of elastic cords. IMPORTANT: make sure that the tubular webbing does not twist and that it sits flat on the table. If webbing twists, the sling will not be comfortable.
[0041] 15. Bartack elastic cords in place near the end of the elastic cords ( FIG. 22 ). TIP: As performed above, pinch elastic cords together during the first 2 thread passes to ensure elastic cords stays centered in the tubular webbing. The longer piece is now complete.
[0042] Shorter Piece
[0043] 16. Insert bungee pieces (2) into one end of the shorter webbing piece.
[0044] 17. Sear this end (on both sides) as seen in FIG. 24 .
[0045] 18. Now sear the opposite end (on both sides), sealing the elastic cords into the longer strap ( FIG. 25 ).
[0046] 19. Take the end farthest from the elastic cords and thread the swivel connector onto the strap ( FIG. 26 ).
[0047] 20. Then thread the male part of the QRB as shown in FIGS. 27 & 28 .
[0048] 21. Next, thread the end of the strap back through the loop of the swivel connector as seen in FIG. 29 , to finally rest up against the male QRB ( FIGS. 30 & 31 ). IMPORTANT: The total distance between the inside edge of the male part of the QRB and the fold should be no longer than 2¾. ( FIG. 32 ).
[0049] 22. Sew a 2 inch box X into place ( FIG. 33 ). IMPORTANT: The box X can be no longer than 2″.
[0050] 23. To determine proper placement of label, fold strap at the swivel connector ( FIG. 34 ).
[0051] 24. Place label with the right-side edge lining up with the male part of the QRB ( FIG. 35 ). Make sure label is oriented properly (as seen below) and not upside down.
[0052] 25. Sew on label ( FIG. 37 ). IMPORTANT: Proper placement of label (without being twisted or crooked) is ESSENTIAL to Tactical Link.
[0053] 26. Next, mark the free end of strap 4½ inches from the end ( FIG. 38 ).
[0054] 27. Bartack elastic cords in place near the end of the elastic cords ( FIGS. 38 & 39 ) with 2 bartacks ¼ inch apart from each other. TIP: As performed above, pinch elastic cords together during the first 2 thread passes to ensure elastic cords stays centered in the tubular webbing.
[0055] 28. Compress elastic cords as far as possible toward the label, leaving a finger widths distance between end of the elastic cords and the edge of the label as seen in FIG. 40 .
[0056] 29. Bartack elastic cords in place near the end of the elastic cords ( FIGS. 41 & 42 ) with 2 bartacks ¼ inch apart from each other. TIP: As performed above, pinch elastic cords together during the first 2 thread passes to ensure elastic cords stays centered in the tubular webbing.
[0057] 30. With the label and triglide facing up, thread the free end of the strap up and into the opening of the common loop ( FIGS. 43-45 ).
[0058] 31. Fold the free end as seen below in FIGS. 46 and 47 .
[0059] 32. Fold under the free end until it touches the common loop ( FIG. 47 ). The width of the fold should be ½ inch (no larger than ¾ inch) as seen in FIG. 47 .
[0060] 33. Sew a ½ inch box X with 6 passes on the top and bottom ( FIG. 48 ).
[0061] 34. Clip any and all loose threads.
[0062] 35. Compare finished product to sample.
[0063] In use, the sling provides a single point of attachment to a weapon. It is to be understood however, that the concept of the present disclosure can be extended to slings providing multiple points of attachment. The user puts the sling strap over their head and rests it on the shoulder of use (left or right). The user thus dons the sling by placing an arm and shoulder (either dominant or non-dominant) through the sling (between the sling and the weapon) and up and over his head. Then they can bring the weapon up into firing position or bring it to striking position and use it to hit without risk of having it dropped or taken away. The user can use the same firing position (weapon mounted to either the dominant or non-dominant shoulder) and simply push the weapon forward to reach out and contact an opponent or object with the weapon's muzzle; or the user can turn the weapon across his body, i.e., barrel pointing to the left and the buttstock pointing to the right, and point the magazine or pistol grip toward the opponent or object and extend the weapon toward the person or object, such as to inflict injury and pain.
[0064] As will be readily appreciated from the foregoing, the bungee sling of the present disclosure allows the sling to expand as well as contract in order to provide two completely separate functions:
[0065] Expand: the elastic bungee sling allows the user to push his weapon away from the user's body (which could not be done with a traditional, fixed/non-bungee sling). Instances of this would be:
[0066] striking an opponent with the barrel or muzzle of the weapon, which helps subdue opponents and encourage compliance with verbal commands,
[0067] striking an opponent with any other part of the weapon, i.e. magazine, grip, etc., which is useful when an opponent is trying to gain control over a user's weapon, and
[0068] lengthening the reach of the weapon to push open a door without the user's body having to get physically closer to the door.
[0069] Shrink/Contract: when stretched or lengthened, the kinetic energy stored up in the lengthened elastic cords inside the sling urges the sling to shrink or contract back to its original length. This is useful to many users because it pulls the weapon back into the user's shoulder, providing a more solid shoulder mount and thus a more accurate shot. Again, this could not be done with a traditional, fixed/non-bungee sling.
[0070] It is to be understood, however, that other materials and finishes may be used as necessitated by a particular application. Hence, while representative embodiments of the present disclosure have been illustrated and described hereinabove, it is to be understood that various changes may be made therein without departing from the spirit and scope of the disclosure. Thus, the disclosure is to be limited only by the scope of the claims that follow.
[0071] All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.
[0072] From the foregoing it will be appreciated that, although specific embodiments of the disclosure have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the disclosure. For example, the concepts of the present disclosure are applicable to slings of multiple points of contact, such as 2-point and 3-point, as well as to connectors that are not necessarily swivel connectors. Accordingly, the disclosure is not limited except as by the appended claims.
|
A sling that includes a first strap having an elastic sidewall enclosing a hollow interior and a pair of elastic cords attached to the strap and located inside the hollow interior of the strap, the first strap further comprising a first connector member on a first end of the first strap; and a second strap having an elastic sidewall enclosing a hollow interior and a pair of elastic cords attached to the strap and located inside the hollow interior of the strap, the second strap further comprising a second connector member on a first end and releasably connectable to the first connector member of the first strap, the first and second straps each having second ends permanently coupled together.
| 5
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The subject matter of this application is related to the subject matter of British Patent Application No. GB 0416736.7, filed Jul. 27, 2004, priority to which is claimed under 35 U.S.C. § 119 and which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of this invention relate to the compensation of errors in the rotor position detector of an electrical machine and particularly, but not exclusively, of a switched reluctance machine.
[0004] 2. Description of Related Art
[0005] The characteristics and operation of switched reluctance systems are well known in the art and are described in, for example, “The characteristics, design and application of switched reluctance motors and drives” by Stephenson and Blake, PCIM'93, Nürnberg, 21-24 Jun. 1993, incorporated herein by reference. A general treatment of the drives can be found in various textbooks, e.g. “Electronic Control of Switched Reluctance Machines” by TJE Miller, Newnes, 2001, incorporated herein by reference. FIG. 1 shows a typical switched reluctance drive in schematic form, where the switched reluctance motor 12 drives a load 19 . The input DC power supply 11 can be either a battery or rectified and filtered AC mains. The DC voltage provided by the power supply 11 is switched across the phase windings 16 of the motor 12 by a power converter 13 under the control of the electronic control unit 14 . Current sensor 18 determines current in at least one of the phases.
[0006] The switching must be correctly synchronized to the angle of rotation of the rotor for proper operation of the drive. A rotor position transducer (‘rpt’) 15 is typically employed to supply signals corresponding to the angular position of the rotor. The rpt 15 is a device that outputs a binary signal having two transitions per machine phase period and is periodic with an electrical cycle of the machine. The transitions are indicative of events in the electrical cycle of the machine, for example occurrences of maximum and minimum inductance, or positions closely adjacent such events, in relation to which a control action is to take place.
[0007] Typically, a set of control laws is programmed into the control unit 14 and these laws are used to operate the drive in response to user demands such as speed or torque. The laws are frequently written in terms of control angles, e.g.: an angle at which excitation is applied to a phase winding; a second angle at which the excitation is removed from the phase; and a third angle describing the duration of any freewheeling period used. While techniques exist for determining these laws empirically for each drive during commissioning, it is more common for a prototype drive to be tested in detail, the control laws determined, and these laws programmed into successive models of the drive, on the assumption that the drives are sufficiently similar that the small differences in performance are insignificant. This procedure does, however, rely on the assumption that the rpt of each drive is accurately built and aligned.
[0008] Many different power converter topologies are known, several of which are discussed in the Stephenson paper cited above. One of the most common configurations is shown for a single phase of a polyphase system in FIG. 2 , in which the phase winding 16 of the machine is connected in series with two switching devices 21 and 22 across the busbars 26 and 27 . Busbars 26 and 27 are collectively described as the “DC link” of the converter. Energy recovery diodes 23 and 24 are connected to the winding to allow the winding current to flow back to the DC link when the switches 21 and 22 are opened. A resistor 28 is connected in series with the lower switch 22 to provide a current feedback signal. A capacitor 25 , known as the “DC link capacitor”, is connected across the DC link to source or sink any alternating component of the DC link current (i.e. the so-called “ripple current”) which cannot be drawn from or returned to the supply. In practical terms, the capacitor 25 may comprise several capacitors connected in series and/or parallel and, where parallel connection is used, some of the elements may be distributed throughout the converter. A polyphase system typically uses several “phase legs” of FIG. 2 connected in parallel to energize the phases of the electrical machine. Instead of the current-measuring resistor, an isolated and/or non-invasive current detector may be used.
[0009] The phase inductance cycle of a switched reluctance machine is the period of the variation of inductance for the, or each, phase, for example between maxima when the rotor poles and the relevant respective stator poles are fully aligned. An idealized form of the inductance curve for a phase is shown in FIG. 3 ( a ). In practice, the sharp corners at L min and L max are rounded due to flux fringing and to saturation of the magnetic circuits. The maximum value of inductance would also be current dependent. Nevertheless, this curve is useful to illustrate the general behavior of the machine. As explained in more detail in the Stephenson paper cited above, the maximum inductance region, L max , is centered around the rotor position where a pair of rotor poles are fully aligned with a pair of stator poles. This is shown for Phase A of a 3-phase, 6-pole stator, 4-pole rotor machine in FIG. 3 ( b ). Similarly, the minimum inductance region, L min , corresponds to the position where the interpolar axis on the rotor is aligned with the stator pole axis, as shown in FIG. 3 ( c ).
[0010] The performance of a switched reluctance machine depends, in part, on the accurate timing of phase energization with respect to rotor position. Detection of rotor position is conventionally achieved by using a rotor position transducer 15 , shown schematically in FIG. 1 , such as a rotating toothed disc mounted on the machine rotor, which co-operates with an optical or magnetic sensor mounted on the stator. A pulse train indicative of rotor position relative to the stator is generated and supplied to control circuitry, allowing accurate phase energization. Typically, a single sensor is used for 1- and 2-phase systems; three sensors for a 3-phase system; and either 4 or 2 sensors for a 4-phase system. Simpler arrangements using only one sensor are occasionally used in systems with three or more phases. Such types of position transducers have a much poorer resolution than, say, a resolver or encoder but are considerably less costly. While it is possible to use highly accurate sensors, the cost involved would have an impact on the overall cost of the drive, particularly in small, low-cost drives.
[0011] FIG. 4 shows in schematic form the essential components of such a rotor position transducer (rpt) for a 3-phase system. The vane 40 is proportioned so as to give an equal mark:space ratio on the outputs of the three sensors. The sensors are distributed around the perimeter of the vane at angles which correspond to the displacement angles of the inductance profiles of the phases, and are typically set relative to the stator poles to give rising and falling edges at L min and L max , respectively. This results in the signals from the sensors having relationships with the inductance profiles of the phases as shown in FIG. 5 . As stated above, the rpt 15 is a device that outputs a binary signal having two transitions per machine phase and is periodic with an electrical cycle of the machine. The transitions are indicative of events in the electrical cycle of the machine, for example occurrences of maximum and minimum inductance, or positions closely adjacent such events, in relation to which a control action is to take place. These signals are typically used by the control system to generate the correct instants for energization of the windings of the machine in accordance with the predetermined control laws. Since the performance of the machine is critically dependent on the accuracy of such energization, it is important that the components of the rpt are accurately made and aligned.
[0012] Several sources of error are commonly found in the rpt. Furthermore, the output of a batch of rpts is not consistent so that each should, ideally, be adjusted individually. The mark:space ratio of the vane obviously affects the mark:space ratio of the output signal, though the relationship is not entirely straightforward, since it is also affected by the properties of the type of sensor used in the rpt. For example, if the sensor is of the optical type, it will have a finite beam width. This will influence the signal differently, depending on whether the transition is from light transmitting to light blocking or vice versa. If the sensor is of the Hall-effect type, then the proximity of the incoming edge of the ferromagnetic vane will give rise to fringing of the magnetic flux and earlier switching than would be expected. In addition, both of these types of sensor can suffer from hysteresis effects, giving variations in signal output depending on the direction of rotation. In order to counter these effects, it is known to adjust the physical mark:space ratio of the vane so as to give a sensor output which is more nearly unity mark:space. It is also known to offset the alignment of the vane on the rotor in order to at least partially compensate for hysteresis, magnetization precision, beam-width and/or fringing effects. Nevertheless, it is not usually possible to compensate simultaneously for all the errors, so at least some errors usually remain in the output signals.
[0013] These errors, however, are only part of the problem. It will be evident from FIG. 4 that both the absolute position of a sensor relative to the stator and its position relative to the other sensors will affect the phase of the RPT A , RPT B and RPT C signals relative to the inductance profile of their phase. Methods have therefore been developed to reduce manufacturing errors in the placement of the sensor components, which are normally arrayed on a printed circuit board. For example, U.S. Pat. No. 5,877,568 and U.S. Pat. No. 6,661,140, both incorporated herein by reference, both disclose methods of improving the alignment of the sensors with the stator, though at the expense of additional components and manufacturing processes.
[0014] Similarly, the alignment of the vane relative to the rotor poles affects the phase relationship of the rpt signals with the respective inductance profiles. Among known methods for reducing this error is that disclosed in U.S. Pat. No. 5,786,646, incorporated herein by reference, which uses a specially designed clamp ring and appropriate tooling to fix the vane in a known relationship with the rotor poles.
[0015] These methods, while going at least some way to improving the quality of the rpt output, are expensive in terms of added components, manufacturing processes and/or set-up costs. While this may be acceptable in high-value drives manufactured in low volumes, it is not desirable for low-cost, high-volume drives as used in, e.g., domestic appliances or automotive systems. Nevertheless, such low-cost systems still require accurate rpt signals to produce the high output required of them. There is therefore a need for a method of compensating for the error in the rpt signals in a repeatable and cost-effective way.
SUMMARY OF THE INVENTION
[0016] Embodiments of the invention are particularly applicable for determining error in the output of a rotor position transducer providing binary signals and being arranged in relation to the rotor of an electrical machine to produce no more than two transitions in the binary signals in a phase inductance cycle.
[0017] The techniques discussed in this patent application are quite distinct from known compensations used in resolver or encoder systems. Such systems have high resolution over a mechanical revolution. Compensation for their circumferential misalignment to a shaft can be done by reading, say, the encoder output at two positions and noting the offset in its output, which may be a few counts of position, but can never be less than the resolution of the encoder. Embodiments of this invention, on the other hand, allow correction of an error which is much less than the resolution of the rpt (but still significant with respect to the performance of the drive system).
[0018] Embodiments of the invention may compare the results from several test runs of the drive with each other so as to determine the desired compensation of the rpt of the machine under test compared with the machine from which the control laws of the drive were determined. This comparison can be done at the end of the manufacturing process. The compensation can then be loaded into the control system of the drive so that, when the drive is operating normally in its intended application, the drive is controlled by signals from the rpt which are appropriately compensated.
[0019] Embodiments of the present invention are able to derive error from comparison of the test results to provide optimum performance for the specific application. The accuracy of the selected output compensation is, thus, dependent on the accuracy of the testing and not on the resolution of the rpt.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Embodiments of the invention will be described with respect to the figures, in which like reference numerals denote like elements, and in which:
[0021] FIG. 1 shows a typical prior art switched reluctance drive;
[0022] FIG. 2 shows a known topology of one phase of the converter of FIG. 1 ;
[0023] FIG. 3 ( a ) shows an idealized inductance profile of a switched reluctance machine as a function of rotor angle;
[0024] FIG. 3 ( b ) shows a schematic view of a switched reluctance machine with the rotor in the fully aligned (L max ) position for Phase A;
[0025] FIG. 3 ( c ) shows a schematic view of a switched reluctance machine with the rotor in the fully unaligned (L min ) position for Phase A;
[0026] FIG. 4 shows the elements of a rotor position transducer for a 3-phase system;
[0027] FIG. 5 shows the relationship between the inductance profiles and sensor signals for the transducer of FIG. 4 ;
[0028] FIG. 6 shows an apparatus according to one embodiment of the invention;
[0029] FIG. 7 shows a graph of peak phase current against rpt offset; and
[0030] FIG. 8 shows a graph of acceleration time against rpt offset.
DETAILED DESCRIPTION
[0031] An illustrative embodiment to be described uses a 3-phase switched reluctance drive in the motoring mode, but any phase number could be used, with the drive in either motoring or generating mode, i.e. producing output as a torque or force, or as electrical power, respectively.
[0032] Referring to FIG. 6 , a switched reluctance (‘SR’) drive as shown in FIG. 1 is set up to be run in association with an error detection unit 64 . The rpt 15 is as shown in FIG. 4 , typically with an output relationship to the inductance cycle for each phase of the machine as shown in FIG. 5 . The rpt has two transitions between binary output states in a phase inductance cycle, as shown in FIG. 5 , and the signals from the rpt are fed to the error detection unit as well as to the control system 14 of the drive. In some embodiments of the invention, the error detection unit is able to determine the current in at least one of the phases of the machine, by means of current sensor 18 . Signals from other current sensors associated with other phases may optionally be supplied to the error detection unit 64 .
[0033] FIG. 6 shows the motor connected to a load 19 . In practice, this load can be omitted for ease of test, or it can be a simple flywheel attached to the shaft to increase the inertia and reduce speed ripple, or it can be a conventional load which requires torque from the motor. In the latter case, the increased phase currents may allow more accurate determination of drive performance and hence more accurate determination of the desired compensation in the rpt. If the test is to be done in the generating mode, the load 19 must be capable of providing torque to the SR machine 12 .
[0034] In one embodiment of the invention, the machine 12 is run by its own power converter 13 under the control of the control unit 14 , responsive to signals from rpt 15 . The control unit implements the control laws programmed into the drive which are appropriate for a drive with a correctly constructed and aligned rpt. The control unit 14 is also able to accept a value of rpt compensation from the error detection unit 64 which is used to offset the control laws relative to the position signalled by the rpt. The drive system is operated against a known load and a selection of parameters, indicative of performance, is recorded by the error detection unit. The parameters included in the selection are determined in advance and may include some or all of the supply voltage, the DC link current, the phase current(s), the efficiency, the power factor seen by the supply, the harmonic voltages or currents injected back to the supply, the machine rate of change of output (e.g. acceleration), the machine output (e.g. torque), torque ripple, machine vibration, acoustic noise, temperature of machine component, etc. Other embodiments of the invention use a waveform as one of the parameters, e.g. a waveform of current, of torque ripple or of acoustic noise.
[0035] In a first test of the rpt 15 carried out according to a program running in the control unit 14 , the machine 12 is run using the control laws programmed into the algorithm. The output of the rpt 15 is used in an unmodified form as the rotor position feedback information. The error detection unit 64 is programmed to add a positive or a negative increment to the candidate rotor position compensation values produced before it is applied to the control laws. Subsequent tests use the output of the rpt 15 . For each setting of rpt output compensation, the chosen performance parameter (or set of parameters) is recorded for later comparison.
[0036] This process uses a series of different candidate values of rpt compensation. The error detection unit then assesses the results of the tests by comparing the parameter values to determine the candidate value of compensation which gives the “best” result. The choice of “best” result will be influenced by the particular application for the drive. For example, drive efficiency could be an appropriate parameter to maximize if the drive is supplied from a battery; peak current could be minimized if there is a limit imposed by the switching devices; time to reach a certain speed could be minimized if the acceleration of the drive is a critical parameter. Many other such comparisons e.g. temperature of the machine winding or some other component, vibration or acoustic noise, will be apparent to one skilled in the art.
[0037] The comparisons to produce the optimum compensation value may be done manually, e.g. by consulting a table containing the test results, but it is advantageous for embodiments of the invention to do the comparisons automatically by the error detection unit 64 . The compensation increment, and direction of the increment (positive and negative), is automatically set to produce a set of parameter values at the end of the tests. However, the compensation increment also is more adaptively determined in the test program, according to one embodiment, by monitoring the parameter value curve. Additionally to this, the monitoring may perform an iterative function to settle on an optimum value of parameter. To use an adaptive technique such as this, the error detection unit 64 optionally is loaded with a suitable genetic algorithm. The selected compensation value can then be transmitted to the control unit 14 through data bus 66 and stored in memory resident in the control unit 14 . When the drive system is subsequently operated in its intended application, the control unit uses the stored compensation value to compensate the output of the rpt and to enable improved performance from the drive.
[0038] Thus the apparatus shown in FIG. 6 can be used for a one-off analysis of a drive system at the end of its manufacture to determine the desired compensation in the rpt system. This is achieved without additional or specialized components. A permanently installed current sensor may not be required for the drive. Instead of the prior art methods of seeking to minimize the error in rpt signals, embodiments of the invention accept that the outputs of rpts are subject to variation and compensate for this so as to optimize the performance of the drive according to a chosen criterion. Embodiments of the present invention have the additional benefit of enabling the machine drive to be set up for optimum performance of a chosen parameter by compensating for the rpt output regardless of its inherent inaccuracy.
[0039] By way of illustration, FIG. 7 shows a graph of peak phase current against rpt offset as would be expected from test runs on an exemplary drive, if such test runs occurred, as described above. It is apparent from this curve that, to minimize the peak phase current, a value of around 2° should be chosen for the rpt error.
[0040] By way of further illustration, FIG. 8 shows the acceleration time between two chosen speeds for another exemplary drive. Again, the graph is as would be expected from test results from a series of tests with varying offset values used for the rpt signals, if such tests were run. In order to minimize the acceleration time, an offset of around −4° should be chosen. A value of compensation may be stored and used for all the phases to save time on analysis, or the selection process can be such that a second or more phases in the machine 12 are allocated compensation values which may be used in association with the individual phases or may be averaged. Similarly, the process can be carried out on only one transition of the rpt signal or on several or all, allowing either an average offset to be calculated or storage of the actual compensation associated with each signal edge.
[0041] The stored compensation value(s) derived from the rpt calibration carried out is then applied by the control unit to the actual rpt signal transitions to compensate for inherent variability in the rpt output and/or to set the rotor output to optimize a chosen parameter performance. It will be apparent to those skilled in the art of digital signal processing that the compensation of the rpt signals could be achieved in a variety of ways once the basic rpt calibration has been performed. This could include, for example, compensation of errors relating to both rising edges and falling edges in the rpt signal. The compensation for the error could be done in either the rotor angle domain or in the time domain and the choice between the two would be influenced by the particular control implementation used by the subject system. The ultimate goal, however, remains that of ensuring that the switches controlling the phase winding(s) are operated at the correct moments and that the operation is not compromised by any error in the rpt signal(s).
[0042] It will also be appreciated by those skilled in the art that the error detection unit 64 could, to a greater or lesser degree, be integrated with the control unit 14 of the drive (see FIG. 6 ). Thus, it may be possible to employ the processing power of the control unit to perform the desired calculations and to store the resulting values of rpt offset compensation. Such an embodiment may allow the drive to be re-calibrated in its application if the settings of the rpt were disturbed during maintenance or repair. The re-calibration exercise could provide a new set of values to be stored and subsequently used for compensation of the rpt output signals.
[0043] The skilled person will appreciate that variations of the disclosed arrangements are possible without departing from the invention, particularly in the details of the implementation of the algorithms in the error detection unit. It will be appreciated that it is possible to store different compensation values (or sets of compensation values) to optimize different parameters so that, for example, a drive could be compensated to maximize either peak acceleration or power factor, depending on a user-selected choice. It will also be apparent that, while techniques according to embodiments of the invention have been described in relation to a switched reluctance machine, they can be used in relation to any machine using rotor position information in its control.
[0044] Also, while the embodiments of the invention have been described in terms of a rotating machine, embodiments of the invention are equally applicable to a linear machine having a stator in the form of a track and a moving part moving along it. The word ‘rotor’ is used in the art to refer to the movable part of both rotating and linear machines and is to be construed herein in this way. Accordingly, the above description of several embodiments is made by way of example and not for the purposes of limitation.
|
An electrical machine has a rotor position transducer which provides output signals to a control system. The output signals contain errors due to component shortcomings and manufacturing imperfections. A method is disclosed which is able to determine the errors in the signals by successively running the machine with a series of assumed errors in the rpt signals and building up a set of test results. These results are subsequently compared with each other so as to determine the optimum value of corrections to the control system of the machine. The correction may be stored in the control system and used to improve the accuracy of the transducer output signals, thus improving the output of the machine.
| 7
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to and is a divisional of U.S. application Ser. No. 12/889,580 filed Sep. 24, 2010 which is a divisional of U.S. application Ser. No. 12/507,100 filed Jul. 22, 2009 which is a divisional of Ser. No. 11/371,940 filed on Mar. 10, 2006.
FIELD OF INVENTION
The present invention relates generally to the field of power electronics and, more particularly, to an optically turn-on and turn-off power thyristor.
BACKGROUND OF THE INVENTION
Compared to other semiconductor power switching devices like MOSFETs and IGBTs, the thyristor is generally known for its ability to sustain large current and its ability to be switched at high voltage. With a low on-state voltage drop for a given current density, a thyristor provides one of the lowest power dissipations among power semiconductor devices. A thyristor typically has four basic semiconductor layers, the emitter, base, drift and anode layers, respectively, with an alternative doping profile to form three junctions. Adjacent layers are oppositely doped with high doping on two outer layers and light doping on inner layers. When a voltage is applied between the anode electrode and cathode electrode, at least one junction is reverse biased to sustain a majority of the applied voltage, and the voltage is held mainly across the lightly doped drift layer until its breakdown.
A thyristor can be viewed as a pair of back-to-back coupled bipolar junction transistors. The lightly doped inner regions act as the base of two transistors. When a thyristor is under high voltage without protection, the leakage current across the lightly doped regions serves as the base current of the transistors and is amplified. When there are enough earners inside the inner layers, the device is turned on. The first method of turning on a thyristor is, in fact, to apply a voltage higher than its blocking value. When the applied voltage is high enough, the thyristor is turned on through the current gain of the leakage current. However, the turn-on voltage is not precisely controllable and high voltages sometimes induce damage inside the device through breakdowns. In practice, the leakage current diverting structures like the cathode short and the anode short are added in the design to enhance the voltage holding capability.
For more controllable turn-on switching, the carriers are injected from a gate electrode on one of the inner layers. Usually, the gate current is only injected over a portion of the base layer, so the conducting current of a thyristor is not fully spread over the whole layer initially. The thyristor will not be fully turned on until carriers spread across the layer by lateral diffusion. The time of carrier spreading depends on the lateral diffusion velocity, which limits the turn-on time. One way to circumvent the slow turn-on time is to inject the gate current over a large area. This may, in practice be implemented with inter-digitization of the gate electrodes and reduces the active cathode area for supporting high current.
An alternative approach for turning on a thyristor is to generate carriers locally inside the inner junctions through absorption of light. There have been several attempts in the prior art to use a photonic gate over the cathode area which permits light to pass through. Photo-generated carriers acting as the gate current injection in the base region start the turn-on process. With appropriate selection of the light wavelength, the depth of the light absorption across the device can be varied to fit different junction depths. Furthermore, a high level of illumination across the whole thyristor structure can instantaneously generate a high density of carriers across the whole device. The high density of carriers collapses the junction voltage and generates the current flow instantly without much delay from carriers being transported through the thyristor drift layer and the lateral diffusion from the gate electrode area to the main cathode area. Therefore, a light controlled thyristor has the advantages of shorter turn-on delay time and shorter turn-on time.
In practice, thyristors are employed in power circuits with high voltages and large currents. The trigger circuit to switch a thyristor through the gate electrode is difficult to isolate from high voltages. Instead of triggering through an electrical gate current, a high degree of electrical isolation between the power and trigger circuit may be achieved by switching with light through optical wave guide-like fibers.
Power MOSFETs and IGBTs will be switched off if the gates are turned off. Due to the self-sustaining effect of a thyristor, the current conduction of a thyristor will continue even after the gate is turned off. A thyristor does not need to maintain the gate injection like other power semiconductor devices. However, the gate of a thyristor loses control after the thyristor is switched on. To actively switch a thyristor from its on-state to the forward-blocking state can only be accomplished by reducing its current below a threshold or by reversal of the anode voltage. In an AC circuit, a thyristor is switched on and off in a cycle while the polarity of the voltage is alternative across the anode and cathode electrodes. However, it is not practical to switch polarity to reverse the anode voltage of a power device in many applications. Typically, the thyristor current is drained through a reverse gate current during turn-off.
In early attempts, the Gate Turn-Off thyristor (GTO) utilized an external control circuit to reverse the gate current and the MOS Controlled Thyristor (MCT) incorporates parallel MOSFETs to create emitter shorts. The external control circuit of a GTO diverts the current through the gate electrode and needs to carry a similar amount of current as a thyristor in order to switch off the thyristor. The diverted current is much larger than the turn-on gate current and this increases the difficulty of the control circuit design. Typically, the external current-diverting circuit of a GTO is much bigger in order to accommodate large thyristor current and there is basically no electrical isolation between the power and trigger circuits. On the other hand, a MCT uses MOSFETs to short the emitter and the base of a thyristor. Like the case of the external turn-off circuit of a GTO, MOSFETs in a MCT also need to take on the majority of the thyristor current. However, the current carrying capability of a MOSFET is limited by its surface channel and is much smaller than the bulk of a thyristor. Therefore, massively parallel MOSFET unit cells are integrated in order to carry large current. The MOSFETs occupy large real estates and limit the main conduction area of a MCT. Hence, MCTs have not been widely used for practical applications.
The limitation of the electronic switching-off of a thyristor is either due to the current carrying capability of MOSFETs to create emitter shorts or the limited current and speed of external current-diverting circuits. In addition, the electronic on-activation of a thyristor suffers slow turn-on and long delay due to the limited speed of carrier transport. A new control technique is needed to improve these short falls.
In earlier attempts, a photonic gate was employed in the light controlled thyristor to permit light. The illumination of light through the photonic gate generates carriers in the base region as the gate current injection to turn on the device. However, an external circuit is still employed for turning off a light controlled thyristor to divert the conducting current as a GTO. Various attempts with alternative electronic switching-off schemes also suffer similar shortfalls. Hence, the light controlled thyristor did not solve the whole problem that limits thyristors in many applications.
To improve the turn-off limitation of the light controlled thyristor, a photonic controllable switching structure was introduced on a thyristor. In O. S. F. Zucker et. al. (U.S. Pat. No. 6,218,682 B1, Apr. 17, 2001), the optically-activated thyristor adds an external shorting structure on top of a light activated thyristor. The shorting structure is electrically and mechanically bonded across the emitter and base region of a thyristor. The added shorting structure comprises a PN junction and has an optical aperture for introducing light. Furthermore, an aperture over the emitter region for permitting light is introduced to better utilize the wafer surface area for current conduction instead of separated photonic gates. Therefore, a high level of light illumination may be introduced through the aperture to generate high density carriers in the bulk of the thyristor to direct short the whole device for fast switching on. During the conducting state of the thyristor, the shorting PN junction is open and under the back bias. When light is introduced onto the shorting structure, the photo-generated carriers collapse the voltage and electrically short the cathode and the base of the thyristor to create emitter shorts. The illuminated shorting structure diverts the conducting current to bypass the emitter and then turns off the thyristor. However, the main thyristor structure and the shorting structure are fabricated separately on different semiconductor wafers. The wafer with the shorting structure is then diced and externally bonded on the main thyristor structure. In addition to the alignment of the optical fibers to apertures, additional alignment and bonding of the shorting structure to the main thyristor structure in the back end processing increase the complexity and cost of the fabrication.
Accordingly, there remains a need for an improved light activated thyristor. There remains a further need for a thyristor that is compact and monolithically integrated, so that the complexity and cost of fabrication may be greatly reduced to fit practical applications.
SUMMARY OF THE INVENTION
According to the present invention, a monolithic, high power thyristor on a semiconductor wafer is provided. The thyristor may incorporate photonic switching control. The monolithically integrated light activated thyristor comprises four alternatively doped layers of a basic thyristor structure, an emitter, a base, a drift and an anode layer, respectively, and additional two oppositely doped zones monolithically integrated on top of the emitter layer. The added two oppositely doped zones may be formed of the same or different semiconductor materials. According to one embodiment, the adjacent layers and zones of the monolithically integrated light activated thyristor are of the opposite doping and form an n-p-n-p-n-p structure.
During the on-state of the thyristor, the two oppositely doped zones on the top form a back-biased PN junction acting as a switching diode. The zone adjacent to the emitter layer with the opposite doping is electrically shorted with the emitter layer on the top surface to the cathode and the other is electrically connected to the base layer through interconnect over an insulating layer. Two apertures for permitting light control are formed by openings of the cathode electrode over the emitter region and of the floating gate over the junction of the switching diode. The construction of the monolithically integrated light activated thyristor is achieved through the processes of spatially doping and/or depositions on a single semiconductor wafer, without any external attachment of addition semiconductor devices.
The overall device consists of multiple cells of functionally identical units. In each unit device, there are two sets of optical apertures on the top surface: one is on the cathode acting as a gate for the turn-on process; the other is over the back-biased junction of the embedded switching diode acting as a switch to turn off the thyristor.
According to one embodiment, a method of activating the thyristor incorporates applying a voltage across the top emitter layer and the bottom anode layer of the semiconductor device. The turn-on process is achieved by illuminating light through the cathode aperture and photo-generating carriers on the base layer and the drift layer acting as the gate current injection. Furthermore, a high level illumination generates a high density of charged carriers to collapse the voltage across the blocking junction and turns on the whole device through direct current flow and/or lateral carrier diffusion. The device is kept on through the thyristor regenerative action even when the illumination is stopped.
According to another embodiments, an embedded back-biased switching diode structure incorporated on top of the emitter layer seizing as a turn-off switch between the cathode electrode and the base layer. When illuminating the aperture over the junction of the embedded switching diode, the photo-generated carriers collapse the back-biased junction and electrically short the base layer and the cathode. The current then bypasses the emitter layer to stop the injection through the emitter-base junction. Hence, the current diversion stops the thyristor regeneration effect and turns off the thyristor when the current is reduced below the holding level.
The light controlled turn-on and turn-off processes allow the electrical isolation of the trigger circuit from high voltages and have a capability of remote control through a light guiding scheme such as the utilization of optical fiber. Moreover, the present invention allows the turn-off switch diode structure to be monolithically integrated into the same semiconductor wafer during fabrication. The embedded switching diode can be incorporated in the fabrication process, without any bonding or integration of the external switching device in the back-end process. The present invention accordingly provides a better integration of power semiconductor devices in many circuits and reduces the complexity and cost of fabrication.
The above described features and advantages of the present invention will be more fully understood with reference to the detailed description, drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows, in cross section, a unit cell of an embodiment comprising a four layer thyristor structure, an embedded turn-off switching diode, and two separated optical apertures for turning on and off control with light beams, according to an embodiment of the present invention.
FIG. 2 shows, in cross section, a unit cell of the embodiment in a non-planar construction. The layer structure is formed through multiple steps of spatial doping processes and/or depositions and etching, according to an embodiment of the present invention.
FIGS. 3A and 3B show circuit representations according to an embodiment of the present invention.
FIGS. 4-17 show the various steps of a fabrication process, according to one example of an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to a high power, monolithically integrated thyristor-based device with a switching diode structure that incorporates optical on and off control.
The semiconductor devices described herein are based on the use of light to actively switch on and/or off, and are referred to by the generic name “light controlled thyristors” (LCTs) or “optically controlled thyristors” (OCTs). Optical activations involve illuminating a semiconductor device with light to create electron-hole pairs at the site of absorption and do not require the injection of carriers through carrier transport. Hence, the optical activation of the device may be faster than the injection, which is limited by drift velocity and lateral diffusion of carriers.
In addition to switching on, the present invention provides the ability to actively switch off a power semiconductor device with light. The underlying principle for switching off a thyristor is to create an electrical short across the emitter-base injection junction. The emitter short is accomplished by using light to illuminate the back-biased junction of the embedded-switching diode structure connecting the base layer and the cathode electrode. The selection of the optical wavelength of the activating light results in an ability to control the absorption length, and hence the volume and depth of the semiconductor material activated by the light. In addition, the carrier concentration in the switching junction may also be controlled by the amount of light.
The illuminating light may be generated by a separate circuit far from the power circuit. Light may be introduced into the device through an optical wave-guide, such as an optical fiber. The electrical isolation of the trigger circuit from the main power circuit may be realized by photonic switching on and off. Furthermore, the monolithic integration of switching-off diodes, according to an embodiment of the present invention, allows an optically controlled thyristor to be fabricated on a single semiconductor wafer and reduces the complexity and cost of fabrication.
According to an embodiment, an array of functionally identical unit cells is introduced onto a semiconductor wafer. The total number of unit cells may be varied to fit the requirement of applications with different layouts. An example of fabrication steps of a unit cell of the preferred embodiment is illustrated in FIGS. 4-17 .
Referring to FIG. 4 , beginning with a portion of a lightly doped n-type semiconductor wafer 200 , a n-type drift layer 204 is sandwiched by two p-type layers (the base layer 204 on the top and an anode layer 206 on the bottom). The two p-type layers and subsequent layers may be formed by diffusion, ion implantation, epitaxial growth, or any other appropriate technique. The p-type anode layer may be heavily doped and the p-type base layer may be lightly doped.
An additional n-type-emitter layer is then introduced onto the top p-type base layer 202 , as shown in FIGS. 5 and 6 . The profile of the emitter layer is formed by coating the top surface of the p-type base layer 202 with a masking layer of suitable choice for photo-resistance. The masking layer initially covers the whole surface, and portions are removed by the photo-lithographic technique to form a masking pattern 230 as shown in FIG. 5 . The covered areas of the masking pattern are for a plurality of cathode shorts and gate contacts. The top emitter layer 208 is then introduced by diffusion or ion implantation on the opening as shown in FIG. 6 . The resulting semiconductor body 200 has the basic n-p-n-p structure of a thyristor with a plurality of cathode shorts 207 and gate contacts 209 on the top surface. Various modifications may be made in terms of doping profile and layer thickness to optimize the device electronic properties such as maximum forward and/or reserve blocking voltage, switching characteristics, and other properties.
A second masking pattern 232 , as shown in FIG. 7 , covers portions of the top surface of the emitter layer 208 and has an opening for the introduction of an additional p-type doping zone 210 by diffusion or ion-implantation as shown in FIG. 8 . Subsequently, a third masking pattern 234 as shown in FIG. 9 may be introduced on top of the p-type zone to add a n-type doping zone 212 as shown in FIG. 10 . The last two oppositely doped zones, 210 and 212 , form a PN junction and that may act as a switching diode 211 for the turn-off process.
An insulating layer 214 is deposited to cover the top surface of the semiconductor body 200 as shown in FIG. 11 . The anode electrode 216 may be added by a contact metallization on the bottom surface as shown in FIG. 12 . For the top metallization, the insulating layer 214 on the top surface may be first masked with the pattern 236 as shown in FIG. 13 . The opening portions of the insulating layer are removed by etching. The top is then metallized to form the cathode electrode 224 , the gate electrode 226 and the cathode (n-type) end contact 228 of the switching diode as shown, for example, in the steps illustrated in FIGS. 14 and 15 . The n-type emitter layer 208 and the anode (p-type) zone 210 of the switching diode are electrically shorted by the cathode 224 . In addition, a plurality of the cathode-shorts 207 distributed on the cathode electrode 224 of a device suppress the gain of the parasitic top NPN transistor to improve the forward blocking voltage.
The insulating layer is transparent to light and two optical apertures 218 and 220 in each device unit resulted from the masked and un-etched areas on the top surface. The optical aperture 218 is an opening in the cathode electrode over the emitter layer for permitting turn-on light. The optical aperture 220 is over the junction area of the embedded switching diode 211 .
The gate 226 and the diode cathode contact 228 are linked by first masking the top surface with the pattern shown in FIG. 16 and interconnecting with subsequent metallization over the insulating layer as shown in FIG. 17 . The floating gate comprised of the interconnect 222 , the gate 226 and the diode cathode contact 228 is kept floating during operation and diverts the thyristor current when the embedded switching diode is shorted by light.
Another embodiment is shown in FIG. 2 with a non-planar construction. The layers of the embedded switch-off diode-structure may be deposited epitaxially or in poly-crystallized form, or wafer bonded on top of the emitter layer. The wafer bonding may involve bonding wafers together having the same and/or different materials. The non-planar construction may be fabricated by following a mesa etching processes. The top surface may also be smoothed through the standard planarization process or any other process. The deposited layers may be different semiconductor material from the underlying layers of the basic thyristor structure for selection of optical wavelength.
Having described planar and non-planar embodiments and associated methods of manufacturing, it will be understood by those having ordinary skill in the art that changes may be made to those embodiments without departing from the spirit and scope of the present invention.
In operation, the monolithically integrated light activated thyristor 200 in FIG. 17 may be connected to a circuit through the anode electrode 216 and the cathode electrode 224 , while the floating gate electrode 222 is kept floating. For a forward blocking operation, the anode electrode 216 may be forward biased relative to the cathode electrode 224 . Under high voltage, a small forward leakage current may pass through the device and multiple cathode-short regions 207 in a device provide a protection against premature turn-on through the leakage current gain. In addition, a voltage holding capability exists and may be enhanced through manipulation of resistivity across the embedded switching diode 211 . Illuminating light through the aperture 220 also may create cathode shorts through the change in resistivity of the embedded diode.
In the turn-on process, a light pulse is initially introduced through the turn-on aperture 218 , preferably via an optical fiber, to illuminate the main body of the thyristor 200 . The optical pulse generates a dense concentration of electrons and holes through absorption across the device. The photo-generated carriers, acting as the base current injection from the gate in the conventional thyristor, collapse the depletion region across the p-type base region 202 and the n-type drift region 204 . Shorting the n-type emitter layer 208 and the n-type drift layer 204 results in the forward conduction state.
The thyristor 200 stays on through regenerative action even after the light is turned off. The turn-on process, utilizing light activation, is relatively fast compared to electronic turn-on thyristors. To generate photo-carriers, the photon energy of the light pulse should be above the energy band gap of the semiconductor material in use. The penetration depth of the light in the device may be adjusted by varying the wavelength of the activation light such that the illuminating light reaches through the p-type base layer 202 and into the n-type drift layer 204 .
In an embodiment of the monolithically integrated light activated thyristor, the embedded switching diode 211 is comprised of the p-type region 210 and the n-type region 212 . The cathode electrode 224 lays over both the n-type emitter 208 and the anode (p-type) junction side 210 of the switching diode 211 . The p-type base layer 202 is electrically connected to the cathode (n-type) junction side 212 of the switching diode 211 through the floating gate 222 and is insulted with a dielectric layer from the p-type region 210 of the switching diode 211 and the n-type emitter region 208 . While the thyristor is under forward bias, the PN junction of the embedded switching diode 211 is back-biased, with high resistance.
To turn off the thyristor, the embedded switching diode 211 is illuminated with a through the turn-off aperture 220 . This results in the p-type base layer 202 being electrically shorted with the cathode electrode 224 . The emitter short results in current bypassing the n-type emitter region 208 . Subsequently, it terminates the self-injection into the p-type base layer 202 and turns of thyristor 200 .
In order to avoid unwanted carrier injection onto the p-type base layer 202 during the turn-off process, the illuminated light should have a shorter absorption depth compared to the turn-on light such that it does not reach the depth of the p-type base layer 202 . As mentioned above, an appropriate wavelength may be selected to fit the requirement. In addition, the deposition of different semiconductor materials also may accommodate different absorption wavelengths such that the thyristor structure is transparent to the turn-off light. The resistance of the switching diode 211 may be controlled by the amount of light introduced through the aperture 220 . To prevent the high dV/dt turn-on during the forward blocking state, a low level of light may be introduced onto the switching diode 211 to accommodate the rapid change of the anode voltage in a circuit. In addition to the cathode short 207 , a low level of illuminating light also lowers the resistance of the switching diode 211 to pass through the induced current flow due to the built-in capacitance of the thyristor 200 . The low level light may be turned off during the turn-on process so as to maintain the on-state voltage drop across the n-type emitter 208 and the p-type base 202 .
In summary, according to an embodiment of the present invention, during the forward blocking state of the thyristor 200 operated in a circuit, the resistance of the embedded switching diode 211 is modulated by low level light so that a resistive emitter-short is created to increase the dV/dt hold-off capability. The elimination of the low level light through the aperture 200 recovers the high resistive state of the switching diode 211 for the thyristor on state. To turn on the thyristor, a high level of illumination through the aperture 218 generates photo-carriers across the main body of the thyristor 200 and turn-on the device. To turn off the activated thyristor 200 , a high level light is introduced onto the embedded switching diode 211 through aperture 220 to create an electrical short between the p-type base layer and the cathode 224 to terminate the self-injection within the thyristor 200 and turn off the thyristor 200 . Once the thyristor 200 is turned off, the illumination of a low level light over the embedded switching diode 211 may be resumed to enhance the dV/dt hold-off capability in addition to the cathode short. FIGS. 3A and 3B depict potential schematics of this design according to an embodiment of the present invention. Referring to FIG. 3A , three devices are illustratively shown coupled together, respectively 300 , 305 and 310 . A N type region of device 300 is illustratively shown as coupled to respective P type regions of devices 305 and 310 . This node has been described herein as a floating gate node. A P type region of device 300 is shown as coupled to the cathode and one of the N type regions of device 310 . The other N type region of device 310 is shown coupled to the N type region of device 305 . The other P type region of device 305 is coupled to the anode. Referring to FIG. 3B , devices 320 , 325 and 330 respectively show electrical representations of devices 300 , 305 and 310 .
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
In particular, it be apparent that while particular semiconductor structures have been illustrated and while particular processing steps have been shown, numerous variations are possible and contemplated by the applicants. For example, it will be understood that the circuit shown in FIGS. 3A and 3B may be physically realized in an integrated semiconductor structure in many different ways. The Figures depict one way of implementing an embodiment of the invention in a semiconductor structure. However it will be understood that the semiconductor layering scheme may be changes, and the junction locations and profile, insulator layers and contacts may be changed for any reason. In addition, while silicon has generally be described, it will be understood that any other type of semiconductor structure may be implemented.
|
A monolithically integrated light-activated thyristor in an n-p-n-p-n-p sequence consists of a four-layered thyristor structure and an embedded back-biased PN junction structure as a turn-off switching diode. The turn-off switching diode is formed through structured doping processes and/or depositions on a single semiconductor wafer so that it is integrated monolithically without any external device or semiconductor materials. The thyristor can be switching on and off optically by two discrete light beams illuminated on separated openings of electrodes on the top surface of a semiconductor body. The carrier injection of the turning on process is achieved by illuminating the bulk of the thyristor with a high level light through the first aperture over the cathode to create high density charge carriers serving as the gate current injection and to electrically short the emitter and drift layer. The switching off of the thyristor is achieved by shorting the base layer and the cathode layer by illuminating the embedded back-biased PN junction of the TURN-OFF switching diode. The patterned doping profile and the interconnect between the emitter and the base region of the light activated thyristor makes possible a monolithic and/or plantar integrated fabrication of the semiconductor switching device on a single semiconductor wafer via the standard semiconductor fabrication process.
| 7
|
The present invention is a continuation-in-part of an application filed by us in the United States Patent and Trademark Office on Mar. 8, 1982 under Ser. No. 355,981 for Safety Relief Valve Soft Seat, now U.S. Pat. No. 4,446,886.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to pressure relief valves of the poppet or lift valve type and more particularly to an improved valve seat.
2. Description of the Prior Art
Pressure relief valves of the poppet or lift type generally comprise an elongated valve housing having an outlet port disposed at right angle to its inlet end. The inlet end is provided with a valve normally maintained seated on a seat intersecting the inlet passageway by a spring axially biasing the valve toward its seat in which excess pressure, above a predetermined limit, unseats the valve by compressing the spring.
One commonly used commercial design employs a precision ball valve disposed in a huddling chamber and seating on a finely ground metal seat. This type of relief valve enjoys the economy of manufacture of a precision ball valve member mated with a spherical lapped seat. While economical in manufacture these valves suffer from a relatively short service life due to a rapid deterioration of both the ball valve and the lapped seating surface as a result of mechanical impact while reseating.
This invention provides a greatly improved seating means through unique construction which provides all the economies of a spherical-shaped valve member with the bubble tight qualities of a resilient precision seat. Service life expectancies are on an order of magnitude greater than that of conventional metal ball valves and seats. The uniqueness of the design in part lies in the molding of an elastomer to a metal surface which then maintains the cylindrical precision of a seating lip. Further, the geometry of the seat lip is such that fluid pressure tends to move the resilient lip into bubble tight closure with the spherical valve member. Moreover the metal huddling chamber with limiting surface may be constructed of a material substantially softer than the ball valve member without adversely affecting service life thus permitting further economies in construction.
This invention is distinctive over the above referred to co-pending application by eliminating the sleeve member to which the resilient seal is bonded and bonds the resilient seal to the valve seat body with the latter being roll sealed in place thus further simplifying the valve and reducing its initial cost.
SUMMARY OF THE INVENTION
An elongated generally cylindrical valve housing, having a lateral exhaust port perpendicular to its axial inlet passageway, is provided with a spring urged plunger adjustably disposed axially in its other end portion bearing against a ball valve normally urged toward the housing inlet passageway. An improved seat member is disposed within the housing inlet passageway. The improved seat member is tubular in general configuration forming a huddling chamber at one end portion for the ball valve and defining a beveled annular inwardly converging ball valve stop surface intermediate its ends facing toward the ball valve for limiting movement of the ball valve toward the inlet pasageway. The other end portion of the seat member has a resilient ring seal bonded thereto. The ring seal has an annular surface projecting downstream adjacent the inwardly converging limit of the ball valve metallic stop seat formed by the annular converging surface. The downstream inner edge surface of the resilient ring seal forms a bubble tight seal with the ball valve when the latter is biased toward the inlet passageway in addition to cushioning movement of the ball valve toward its metallic seat.
The principal object of this invention is to provide an improved hard and soft seat assembly secured as a unit in the housing of a pressure relief poppet valve which includes an annular resilient seal disposed and held in place adjacent a ball valve stop surface forming a ring-like bubble tight concentric seal with the ball valve which cushions the shock of the ball valve with its metallic seat surface and materially increases the service life of the relief valve.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross sectional view, partially in elevation, of a pressure relief valve having the improved soft seat assembly installed therein;
FIG. 2 is a vertical cross sectional view, to a larger scale, of the relief valve soft seat assembly and its associated ball valve; and,
FIG. 3 is a diametric cross sectional view of the resilient seal, per se.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Like characters of reference designate like parts in those figures of the drawings in which they occur.
In the drawings:
The reference numeral 10 indicates a relief valve comprising a hollow elongated generally cylindrical valve housing 12 having an internally threaded lateral exhaust port 14. The inlet end of the valve housing threadedly receives inlet means 16 sealed by an O-ring 17 and having external threads 18 and internal threads 19 for connection with a line or fitting, not shown, containing fluid under pressure and forming a fluid inlet passageway 20. The other end portion of the valve housing 12 threadedly receives axially an adjusting screw 22 for adjusting the release pressure rating of the valve. The inward end of the adjusting screw bears against a spring keeper 23 mounted on one end of a helical spring 24 nested by a socket 26 formed in a spring guide 28 normally biasing a ball valve 30 to an inlet passageway closed position by the resilience of the spring.
Soft seat means 32, is nested by a socket 33 in the inward end portion of the inlet means 16, and forms a seat for the ball valve 30 for normally closing the inlet passageway 20. The inward end of the inlet means 16 terminates in a relatively thin annular wall 34 for the purposes presently explained. The soft seat means 32 comprises a generally cylindrical seat support member 35 having one end portion surrounded by the socket 33. Intermediate at its ends the periphery of the seat member 35 is provided with an annular groove 36. The inward end portion of the annular wall 34 is rolled into the groove 36 to anchor the seat member 35. The seat member 35 is centrally bored, as at 38, on a selected diameter smaller than the diameter of the ball valve 30, and is counterbored from its head end, as at 40, for receiving the ball valve 30 and forming an annular shoulder 42 perpendicular to the passageway axis. A portion of the annular shoulder 42 is cut away to form an inclined annular surface 44 converging upstream toward the axis of the inlet passageway 20 and facing toward the ball valve to form a stop and seat limiting movement of the ball valve 30 toward the housing inlet end. The wall at the downstream end of the seat member 35 is further bored to form an inclined surface 48 converging toward the inlet passageway and intersecting the counterbore 40 at substantially the horizontal diametric position of the ball valve 30 when seated in the seat member, as presently explained, thus defining a huddling chamber 50 for the ball valve. The other end portion of the seat member 35 is counterbored, as at 52, on a selected diameter which terminates in an inclined downstream converging surface 54 terminating adjacent but spaced upstream from the central bore 38.
The counterbore 52 and the converging surface 54 cooperatively receive a resilient seal ring 56 which is concentrically secured thereto by bonding, not shown. The seal ring 56 is preferably formed from rubber-like plastic material presently marketed under the trade names Viton or Vespel. The seal ring has an end surface 60 contiguously contacting the seat member surface 54 with the periphery of the seal ring closely nested by the counterbore 52. The innermost wall surface 62 of the resilient ring is substantially parallel with the longitudinal axis of the seat support 35 and defines a diameter of slightly smaller dimension that the bore 38 and this surface 62 intersects the resilient ring seal surface 60 on a relatively small radii 64 facing downstream toward the ball valve adjacent the upstream limit of the ball valve stop/seat surface 44. The seal 56 has a counterbore diameter 66 diametrically equal with the inlet means bore 21. The axial length of the wall surface defining the diameter 66 is substantially equal to one half the length of the seal and intersects a downstream inclined surface 68 substantially parallel with the seal end surface 60. The axial length of the resilient seal 56 is such that its upstream end portion projects beyond the upstream limit of the seat member 35 a selected distance D for the purpose of slightly compressing the resilient seal 56 sufficiently to form a fluid tight seal between the seat member 35 and inlet means 16 but without distorting the seal 56. The distance D is preferably relatively small, on the order of 0.010 inches (0.0254 mm). The inside diameter of the seal, defined by the wall 62, relative to the seat member bore 38 is such that the resilient seal surface 64 is initially contacted by the ball valve 30 in a bubble tight seal before the ball valve contacts the surface 44. Fluid pressure in the inlet passageway 20, opposed by the spring force against the ball valve 30, acts on the inner peripheral inclined edge surface 68 of the resilient seal to enhance the seal ring surface 64 sealing in a line point contact with the ball valve. This results in the ball valve popping or unseating at 1% to 2% of the pressure setting of the valve 10.
When the fluid pressure initially lifts the ball valve out of bubble tight contact with the seal ring surface 64 the escaping fluid is momentarily confined by the huddling chamber 50 so that it is effective on the entire upstream hemispherical portion of the ball valve 30. Stated another way, fluid pressure against the part-spherical portion of the ball valve exposed to the fluid pressure within the inner periphery 62 of the seal ring initially lifts the valve at a predetermined pressure setting wherein the escaping fluid, restricted by the huddling chamber wall 40, is applied to a greater surface area of the ball valve.
Additionally, the inclined annular surface 44 may be lapped at its line point contact with the ball valve 30 for seating therewith thus in effect forming a second or supplemental valve "hard seat" for high temperature installations.
It seems obvious the valve 30 could be a configuration other than spherical if provided with a hemispherical or at least a part-spherical portion, not shown, facing the resilient seal 56.
Obviously the invention is susceptible to changes or alterations without defeating its practicability. Therefore, we do not wish to be confined to the preferred embodiment shown in the drawings and described herein.
|
In a poppet-type relief valve, including a housing having a spring guide assembly axially biasing a valve toward a seat in its inlet passageway, a soft valve seat member is coaxially disposed in the inlet passageway. The soft seat member includes a rigid surface limiting movement of the spring urged valve toward the inlet passageway and further includes a resilient ring seal positioned adjacent the rigid surface in a manner to be cushion contacted by and form a bubble tight seal with the spring urged valve before the valve contacts the rigid surface.
| 5
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.